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Sample records for acrylic intraocular lenses

  1. In vitro study of antibiotic effect on bacterial adherence to acrylic intraocular lenses.

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    Gaál, Valéria; Kilár, Ferenc; Acs, Barnabás; Szijjártó, Zsuzsanna; Kocsis, Béla; Kustos, Ildikó

    2005-11-10

    Implantation of artificial intraocular lenses into the eye during ophthalmic surgical procedures ensures an unliving surface on which bacterial pathogens may attach and form biofilms. Despite antibiotic treatment bacteria growing in biofilms might cause inflammation and serious complications. In this study the adhesive ability of 7 Staphylococcus aureus and 11 coagulase-negative Staphylococcus (CNS) strains to the surface of acrylic intraocular lenses had been examined by the ultrasonic method. In untreated cases adhesion of the S. aureus and CNS strains did not differ significantly. We could not demonstrate significant differences between the adhesive ability of the standard strains and the clinical isolates. In this study a single--60 min long--antibiotic (ciprofloxacin and tobramycin) treatment had been applied, that correlate well with the single or intermittant antibiotic prophylaxis of patients. Ciprofloxacin administration was able to reduce significantly the number of attached cells on the surface of acrylic lenses both in the case of S. aureus and CNS strains. Dependence of the effect from concentration could also be demonstrated. Tobramycin treatment was able to inhibit significantly the attachment of S. aureus cells. Despite the debate on antibiotic prophylaxis we presented in our experiments that a single antibiotic administration can decrease the attachment of bacterial cells to the surface of acrylic intraocular lenses, and might be effective in the prevention of postoperative endophthalmitis, that is a rare but serious complication of ophthalmic surgery.

  2. Calcification of Hydrophilic Acrylic Intraocular Lenses With a Hydrophobic Surface: Laboratory Analysis of 6 Cases.

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    Gartaganis, Sotirios P; Prahs, Philipp; Lazari, Eftichia D; Gartaganis, Panos S; Helbig, Horst; Koutsoukos, Petros G

    2016-08-01

    To investigate the nature and characteristic features of deposits causing opacification of intraocular lenses (IOLs) based on the examination of clinical findings using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) analysis. Retrospective, observational case series. This is a multicenter study of 6 hydrophilic acrylic IOLs (Lentis LS-502-1; Oculentis GmbH, Berlin, Germany) with a hydrophobic surface that were explanted from 5 patients because of opacification. Three patients had an uncomplicated phacoemulsification. One patient underwent combined phacoemulsification and pars plana vitrectomy for retinal detachment and later silicone oil endotamponade owing to redetachment. The last patient had a pars plana vitrectomy and silicone oil instillation combined with phacoemulsification for tractive retinal detachment and diabetic retinopathy. The explanted lenses were submitted to our laboratory and were examined by SEM and EDX in order to identify the morphologic features and the composition of the deposits. SEM and EDX analyses confirmed the presence of calcific deposits in the interior of the opacified hydrophilic IOLs, with a pattern showing the formation of lumps on the surface. The lumps were due to subsurface formation of calcium phosphate crystalline deposits. The crystallite clusters seemed to diffuse from the IOL interior to the surface. We demonstrated the calcification pattern of the hydrophilic IOL (Lentis LS-502-1) with a hydrophobic surface. Although hydrophilic acrylic lenses have a hydrophobic surface, the development of calcification is a possible threat initiating from the hydrophilic subsurface of the IOLs. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Mesopic visual quality after three kinds of aspheric acrylic monofocal intraocular lenses

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    Hai-Lun Ji

    2013-08-01

    Full Text Available AIM:To evaluate best corrected visual acuity(BCVAand contrast sensitivity(CSunder mesopic condition with no glare in patients following implantation of three different kinds of aspheric acrylic monofocal intraocular lens(IOLs.METHODS: Seventy-seven cases(90 eyesof age-related cataract patients were selected, who were undergone phacoemulsification and intraocular lens(IOLimplantation in our hospital during December 2011 to November 2012. Preoperatively, the patients were randomly divided into three groups: 30 eyes(25 caseswere implanted with hydrophobic yellow-tinted acrylic(HOYAIOLs in group 1; 30 eyes(28 caseswith hydrophilic acrylic IOLs(Raynerin group 2; 30 eyes(24 caseswith hydrophilic acrylic surface heparin processing IOLs(XOin group 3. All eyes were evaluated at 1 month and 3 months postoperatively. The BCVA and CS under mesopic condition without glare were measured and underwent statistical analysis.RESULTS: There was neither statistically significant difference in the BCVA(P>0.05, nor statistically significant difference in CS results(after standardization of contrast sensitivity value: lgCS(P>0.05between groups under mesopic condition, but the lgCS of the HOYA group decreased slightly. CONCLUSION: There were not marked differences of BCVA and CS between groups of patients at the follow-up intervals of 1 month and 3 months under mesopic condition. The blue-filter type artificial lens may protect the retina, thus, it is advisable to implant yellow-tinted filter blue artificial lens, especially for patients who are children or young persons.

  4. Aderência in vitro do Staphylococcus epidermidis e da Pseudomonas alcaligenes em lentes intra-oculares In vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to intraocular lenses

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    Patrícia Ioschpe Gus

    2006-06-01

    used in the experiment. Four of polymethylmethacrylate (PMMA, four of silicone, four of hidrogel and two of acrylic. Eight intraocular lenses were placed in eight test tubes containing 4 ml of Pseudomonas alcaligenes suspension, and six intraocular lenses were placed in six test tubes containing 4 ml of Staphylococcus epidermidis suspension. The bacterial suspension used for adherence tests was 10(8 colony-forming units per milliliter (CFU/mL which corresponds to 0.5 in the scale of McFarland. The lenses were incubated at 37° for two hours. After this, intraocular lenses were removed from the test tubes and dried twice with the use of distilled and sterile water. The material was spread on blood-agar for cultivation at 35-37°C and was evaluated every 24 hours up to 72 hours. In the samples where there was bacterial growth, the colonies were counted using the conventional laboratory methods. All assays were performed in duplicate. RESULTS: Adherence of Staphylococcus epidermidis to PMMA intraocular lenses was lower than to hydrogel and silicone intraocular lenses. Adherence of Pseudomonas alcaligenes to hydrogel intraocular lenses was lower than to PMMA, acrylic and silicone intraocular lenses. CONCLUSIONS: Results suggest that in vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to intraocular lenses is influenced by type of material of the lens and by microorganism species. Bacterial adherence may play a role in the pathogenesis of some forms of endophthalmitis after cataract surgery. More in vitro and clinical studies are necessary to elucidate the mechanisms by which Staphylococcus epidermidis and Pseudomonas alcaligenes cause endophthalmitis.

  5. DESIGN OF THE MULTIORDER INTRAOCULAR LENSES

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    V. G. Kolobrodov

    2015-01-01

    Full Text Available Intraocular lenses (IOLs are used to replace the natural crystalline lens of the eye. Just few basic designs of IOLs are used clinically. Multiorder diffractive lenses (MODL which operate simultaneously in several diffractive orders were proposed to decrease the chromatic aberration. Properties analysis of MODL showed a possibility to use them to develop new designs of IOLs. The purpose of this paper was to develop a new method of designing of multiorder intraocular lenses with decreased chromatic aberration. The theoretical research of the lens properties was carried out. The diffraction efficiency dependence with the change of wavelength was studied. A computer simulation of MODL in a schematic model of the human eye was carried out. It is found the capability of the multiorder diffractive lenses to focus polychromatic light into a segment on the optical axis with high diffraction efficiency. At each point of the segment is present each component of the spectral range, which will build a color image in combination. The paper describes the new design method of intraocular lenses with reduced chromaticism and with endless adaptation. An optical system of an eye with an intraocular lens that provides sharp vision of objects located at a distance of 700 mm to infinity is modeled.

  6. Light transmission through intraocular lenses with or without yellow chromophore (blue light filter) and its potential influence on functional vision in everyday environmental conditions.

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    Owczarek, Grzegorz; Gralewicz, Grzegorz; Skuza, Natalia; Jurowski, Piotr

    2016-01-01

    In this research the factors used to evaluate the light transmission through two types of acrylic hydrophobic intraocular lenses, one that contained yellow chromophore that blocks blue light transmission and the other which did not contain that filter, were defined according to various light condition, e.g., daylight and at night. The potential influence of light transmission trough intraocular lenses with or without yellow chromophore on functional vision in everyday environmental conditions was analysed.

  7. Opacification of hydrophilic intraocular lenses after Descemet stripping automated endothelial keratoplasty

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    Morgan-Warren PJ

    2015-02-01

    Full Text Available Peter J Morgan-Warren, Walter Andreatta, Amit K Patel Department of Ophthalmology, Solihull Hospital, Heart of England NHS Foundation Trust, Birmingham, UK Purpose: Opacification of hydrophilic acrylic intraocular lenses (IOLs is an emerging complication following Descemet stripping automated endothelial keratoplasty (DSAEK. We report six cases and review the current literature.Methods: In this retrospective, noncomparative, observational case series, patients with IOL opacification after previous DSAEK surgery were identified from corneal clinic records. Case notes were reviewed for demographic details, indication for DSAEK, IOL model, incidence of rebubbling, and postoperative course.Results: Six patients developed IOL opacification after DSAEK. All patients had Fuchs’ endothelial dystrophy and had previously received hydrophilic acrylic IOL models. Central anterior IOL opacification was noted in all six cases. Five cases (83% had required rebubbling due to dislocated graft tissue, and one had an early postoperative intraocular pressure (IOP rise. Five cases (83% were managed conservatively, and one case with a failed graft underwent redo DSAEK and IOL exchange.Conclusion: Repeated exposure to intracameral air, raised IOP, and other patient influences may be major etiological factors for IOL opacification after DSAEK. We advise avoiding hydrophilic acrylic IOL models in patients who may require future endothelial keratoplasty. Keywords: IOL, DSAEK, lamellar keratoplasty, endothelial corneal transplantation

  8. UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

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    Spyratou, E.; Asproudis, I.; Tsoutsi, D.; Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A.

    2010-01-01

    Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV (λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

  9. UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

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    Spyratou, E., E-mail: ellas5@central.ntua.gr [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece); Asproudis, I. [Department of Ophthalmology, University Hospital of Ioannina, Ioannina, 45110 (Greece); Tsoutsi, D. [Department of Chemistry, University of Ioannina, Ioannina, 45110 (Greece); Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A. [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece)

    2010-02-01

    Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV ({lambda} = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

  10. [Subluxation of hydrophilic acrylate intraocular lenses due to massive capsular fibrosis].

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    Kramer, S; Schröder, A C; Brückner, K; Jonescu-Cuypers, C; Seitz, B

    2010-05-01

    Compared with other biomaterials, hydrophilic acrylate provides better uveal biocompatibility, lower adhesion rates of bacteria and silicone oil, and less glare. Because of reduced capsular biocompatibility, increased fibrosis may initiate dislocation of the intraocular lens (IOL). In six eyes of four patients, enhanced fibroses led to IOL dislocation, leading to an IOL exchange an average of 40 weeks after implantation of the same hydrophilic acrylate lens type. Predisposing factors were found in 90% of all reported cases of IOL dislocation in the literature, but not in the cases described here. The lens type that was implanted was unable to adapt to the massive fibrosis induced by its hydrophilic biomaterial. The pattern of lens opacification should receive attention when one is choosing an IOL type. Eyes showing pseudoexfoliation syndrome as well as post-uveitis eyes might require a hydrophilic IOL for less cellular reaction, whereas a posterior subcapsular cataract might need a hydrophobic IOL to prevent a massive capsular fibrosis. In the case of increased capsular contraction, unreflected YAG laser capsulotomy may result in IOL subluxation when the lens design cannot handle capsule shrinkage, as demonstrated here.

  11. Comparison of the Retinal Straylight in Pseudophakic Eyes with PMMA, Hydrophobic Acrylic, and Hydrophilic Acrylic Spherical Intraocular Lens

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    Ya-wen Guo

    2014-01-01

    Full Text Available Purpose. To investigate the intraocular straylight value after cataract surgery. Methods. In this study, 76 eyes from 62 patients were subdivided into three groups. A hydrophobic acrylic, a hydrophilic acrylic, and a PMMA IOL were respectively, implanted in 24 eyes, 28 eyes, and 24 eyes. Straylight was measured using C-Quant at 1 week and 1 month postoperatively in natural and dilated pupils. Results. The hydrophilic acrylic IOLs showed significantly lower straylight values than those of the hydrophobic acrylic IOLs in dilated pupils at 1 week and 1 month after surgery (P0.05. Moreover, no significant difference was found in straylight between natural and dilated pupils in each group at 1 week and 1 month postoperatively (P>0.05. Conclusions. Although the hydrophobic acrylic IOL induced more intraocular straylight, straylight differences among the 3 IOLs were minimal. Pupil size showed no effect on intraocular straylight; the intraocular straylight was stable 1 week after surgery.

  12. [Comparison of surface light scattering of acrylic intraocular lenses made by lathe-cutting and cast-molding methods--long-term observation and experimental study].

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    Nishihara, Hitoshi; Ayaki, Masahiko; Watanabe, Tomiko; Ohnishi, Takeo; Kageyama, Toshiyuki; Yaguchi, Shigeo

    2004-03-01

    To compare the long-term clinical and experimental results of soft acrylic intraocular lenses(IOLs) manufactured by the lathe-cut(LC) method and by the cast-molding(CM) method. This was a retrospective study of 20 patients(22 eyes) who were examined in a 5- and 7-year follow-up study. Sixteen eyes were implanted with polyacrylic IOLs manufactured by the LC method and 6 eyes were implanted with polyacrylic IOLs manufactured by the CM method. Postoperative measurements included best corrected visual acuity, contrast sensitivity, biomicroscopic examination, and Scheimpflug slit-lamp images to evaluate surface light scattering. Scanning electron microscopy and three-dimensional surface analysis were conducted. At 7 years, the mean visual acuity was 1.08 +/- 0.24 (mean +/- standard deviation) in the LC group and 1.22 +/- 0.27 in the CM group. Surface light-seatter was 12.0 +/- 4.0 computer compatible tapes(CCT) in the LC group and 37.4 +/- 5.4 CCT in the CM group. Mean surface roughness was 0.70 +/- 0.07 nm in the LC group and 6.16 +/- 0.97 nm in the CM group. Acrylic IOLs manufactured by the LC method are more stable in long-termuse.

  13. Magnetic resonance imaging diagnosis of intraocular lenses. Die kernspintomographische Diagnostik der Hinterkammerlinse

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    Tosch, U. (Strahlenklinik und Poliklinik, Universitaetsklinik Rudolf Virchow, Berlin (Germany)); Bleckmann, H. (Strahlenklinik und Poliklinik, Universitaetsklinik Rudolf Virchow, Berlin (Germany)); Kaczmarek, U. (Strahlenklinik und Poliklinik, Universitaetsklinik Rudolf Virchow, Berlin (Germany))

    1994-09-01

    Intraocular lenses were investigated by MRI to obtain information about the quality of this method. In experimental studies, seven lenses of between 0 and 30 diopters were visualized. By MRI it was possible to differentiate the various diameters of lenses. It was not possible to discriminate the material of the intraocular lenses. After these first studies the eyes of two corpses and eight patients were investigated. Because of the resolution of MRI it was possible to tell the diopter of implanted lenses. However, by use of MRI in the regular position, a tilting or decentration of the intraocular lens was demonstrated. (orig.)

  14. Staphylococcus epidermidis biofilm formation and structural organization on different types of intraocular lenses under in vitro flow conditions.

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    Baillif, Stéphanie; Leduff, Frank; Hartmann, Daniel J; Kodjikian, Laurent

    2013-01-01

    To compare the adherence and structural organization of Staphylococcus epidermidis biofilm on intraocular lenses (IOLs). IOLs made of 3 different biomaterials [polymethyl methacrylate (PMMA), hydrophilic acrylic or hydrophobic acrylic] were incubated into an S. epidermidis bacterial solution. Scanning electron microscopy was used to count the bound bacteria and to analyze the structural biofilm architecture. After 4-6 h of incubation, adherence was statistically weakest on the hydrophilic acrylic polymer. On the hydrophobic acrylic material, the bacterial cells tended to cover the substratum in a horizontal spread in a continuous monolayer. On the hydrophilic acrylic material or on the PMMA material bacterial cells tended to form only few, small scattered cell clusters. The data suggest that the pattern of S. epidermidis adhesion varies with the IOL biomaterial. Hydrophobic IOLs seem to be more permissive to S. epidermidis adhesion. Copyright © 2013 S. Karger AG, Basel.

  15. The Effect of Various Contact Lenses on Intraocular Pressure Measurement by Goldman Tonometer

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    Monireh Mahjoob

    2014-06-01

    Full Text Available Background: Today, contact lenses have extensive usages. Contact lens places on cornea, so it may induce variation on cornea and these variations can influence the measurement of intraocular pressure (IOP by Goldman tonometer. The aim of this research was to study the effect of various contact lenses on measurement of intraocular pressure by Goldman tonometer. Materials and Methods: In this study, 80 subjects aged 18-25 were selected randomly among patients of Al-Zahra ophthalmology center. None of them has any eye pathological problems. Before wearing the lens, intraocular pressure was measured, and then patients were divided into two groups of soft and hard contact lenses. Soft and hard contact lenses were placed on the eye for two hours, and the intraocular pressure was measured again. Results: The mean of IOP before wearing contact lenses and two hours later was 15.96 mmHg and 13.93, s respectively. Paired test showed a significant difference between IOP before and after wearing contact lenses (p=0.001.There was no significant differences in mean of intraocular pressure decline before and after placing the contact lens in both soft and hard lenses. Conclusion: According to this study, the intraocular pressure decreases after wearing contact lenses (CL. This decline may be due to variation in properties of cornea after wearing CL that can also affect IOP measurement.

  16. Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children.

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    Das, Pranab; Ram, Jagat; Brar, Gagandeep Singh; Dogra, Mangat R

    2009-01-01

    To evaluate the outcome of intraocular lens (IOL) implantation using capsular tension ring (CTR) in subluxated crystalline or cataractous lenses in children. Tertiary care setting. We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90 degrees up to 210 degrees after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO). Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA) in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation.

  17. Pigment dispersion and chronic intraocular pressure elevation after sulcus placement of 3-piece acrylic intraocular lens.

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    Almond, M Camille; Wu, Michael C; Chen, Philip P

    2009-12-01

    A 55-year-old man had phacoemulsification and implantation of a 3-piece acrylic intraocular lens (IOL) (AcrySof MA60AC) in the right eye. One month postoperatively, the intraocular pressure (IOP) was 48 mm Hg and peripheral transillumination defects were noted in the iris circumferentially, with the IOL optic edge visible as a silhouette. Gonioscopy showed dense pigmentation of the trabecular meshwork in the right eye, but in the left eye, only mild trabecular meshwork pigment was seen, along with a concave peripheral iris insertion. At 21 months, the right eye required 3 medications for IOP control. While pigment dispersion has been widely reported after placement of 1-piece acrylic IOLs in the ciliary sulcus, we conclude that in susceptible individuals with a concave peripheral iris insertion, pigment dispersion can occur with sulcus placement of a 3-piece acrylic model despite its thinner optic and angulated haptics.

  18. Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children

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    Das Pranab

    2009-01-01

    Full Text Available Purpose : To evaluate the outcome of intraocular lens (IOL implantation using capsular tension ring (CTR in subluxated crystalline or cataractous lenses in children. Setting : Tertiary care setting Materials and Methods : We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90° up to 210° after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO. Results : Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Conclusions : Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation

  19. [Reasons for exchange and explantation of intraocular lenses].

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    Neuhann, I; Fleischer, F; Neuhann, T

    2012-08-01

    This study was performed to analyse the reasons for explantation/exchange of intraocular lenses (IOL), which had originally been implanted for the correction of aphakia during cataract extraction. All cases with IOL explantation, which had been performed at one institution between 1/2008 and 12/2009 were analysed retrospectively. A total of 105 eyes of 100 patients were analysed. The median time interval between implantation and explantation of the IOL was 5.9 years (min. 0, max. 29.6). The most frequent cause for the intervention was subluxation/dislocation of the implant in 55.2% of cases. This group comprised 21% of cases with subluxation within the capsular bag in pseudoexfoliation syndrome. Other reasons were optical problems/incorrect IOL power (21%), calcification of hydrophilic acrylic IOL (7.6%), corneal decompensation associated with an anterior chamber lens (4.8%), and single cases with varying problems. The reasons for IOL exchange presented in this study are comparable to those of other series in the literature. Explantations due to optical problems may gain weight in the future due to a rise in refractive procedures and demands. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Biofilm Formation by Staphylococcus epidermidis on Foldable and Rigid Intraocular Lenses.

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    Fazly Bazzaz, Bibi Sedigheh; Jalalzadeh, Monireh; Sanati, Maryam; Zarei-Ghanavati, Syamak; Khameneh, Bahman

    2014-05-01

    Biofilm formation of Staphylococcus epidermidis is a major etiological factor of inducing device-related infections. The ability of biofilm formation by the S. epidermidis was assessed in vitro on two brands of foldable (hydrophilic) and two brands of rigid (hydrophobic) intraocular lens materials in order to investigate the role of lens material in postoperative endophthalmitis. To ensure reproducibility of biofilm formation on intraocular lenses, two strains of S. epidermidis and three quantification methods were performed. The S. epidermidis strains, DSMZ3270 (biofilm-producer) and ATCC12228 (non-biofilm-producer) were applied. Organisms were cultivated on disks of different brands of foldable hydrophilic Intra Ocular Lens (IOL) made of acrylic (Didar, Iran; (A) and Omni, India; (B)), and rigid hydrophobic IOL made of polymethyl methacrylate (PMMA; Didar, Iran; (C) and Hexavision, France; (D)). Biofilms were stained with crystal violet (CV) dye, which is an index of biofilm formation. The bacterial population was counted after biofilm homogenization. Scanning electron microscopy (SEM) was performed to examine the extent of biofilm formation. Adherence of DSMZ3270 strain on both types of foldable and rigid IOLs, was significantly more than ATCC12228 (P brands of foldable and PMMA IOLs. According to statistical analyses the incubation time influenced the biofilm formation on both types of IOLs which meant that by increasing incubation time, the biofilm formation increased. According to the SEM pictures, biofilm seems to be lysed at 72 hours. These data demonstrated that the attachment of bacteria to hydrophilic acrylic IOLs was more than hydrophobic PMMA ones independent of the brand. According to these results the bacterial strain might have more hydrophilic properties. Augmenting the biomass of biofilm by passing of time demonstrated the key role of time in biofilm formation on the IOL surfaces. The differences between IOL brands in the biofilm formation

  1. Bilateral spontaneous subluxation of scleral-fixated intraocular lenses.

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    Assia, Ehud I; Nemet, Arie; Sachs, Dani

    2002-12-01

    Two young men with primary ectopic lenses had intracapsular cataract extraction and scleral fixation of posterior chamber intraocular lenses (PC IOLs) using 10-0 polypropylene sutures tied to the IOL eyelets. Three to 9 years after implantation, spontaneous IOL vertical subluxation occurred in all 4 eyes (5 IOL loops), probably because of suture breakage. Late subluxation of a sutured IOL may occur several years after implantation. Double fixation and thicker sutures should be considered, especially in young patients.

  2. Comparison of Biofilm Formation Capacities of Two Clinical Isolates of Staphylococcus Epidermidis with and without icaA and icaD Genes on Intraocular Lenses

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    Sertaç Argun Kıvanç

    2017-03-01

    Full Text Available Objectives: To compare biofilm formations of two Staphylococcus epidermidis (S. epidermidis isolates with known biofilm formation capacities on four different intraocular lenses (IOL that have not been studied before. Materials and Methods: Two isolates obtained from ocular surfaces and identified in previous studies and stored at -86 °C in 15% glycerol in the microbiology laboratory of the Anadolu University Department of Biology were purified and used in the study. The isolates were S. epidermidis KA 15.8 (ICA+, a known biofilm producer isolate positive for icaA, icaD and bap genes, and S. epidermidis KA 14.5 (ICA-, known as a non-biofilm producer isolate negative for icaA, icaD and bap genes. The biofilm formation capacities of the 2 isolates on 4 different IOLs were compared. Two of the IOLs were acrylic (UD613 [IOL A], Turkey; SA60AT [IOL B], USA, and the other two were polymethyl methacrylate (PMMA (B60130C [IOL C], India; B55125C [IOL D], India. Bacterial enumeration and optical density measurements were done from biofilms that formed on the IOLs. Biofilms were imaged using scanning electron microscopy. Results: Mean bacterial counts on the IOLs were 7.1±0.4 log10 CFU/mL with the ICA+ isolate, and 6.7±0.8 log10 CFU/mL with the ICA- isolate; there were no statistically significant differences. Biofilm formation was lower with acrylic lenses than PMMA lenses with both isolates (p=0.009 and p=0.013. The highest biofilm production was obtained on IOL C (PMMA (p<0.001 and the lowest was obtained on IOL A (hydrophilic acrylic (p<0.001. Conclusion: Bacterial counts after biofilm formation were lower on acrylic lenses, especially hydrophilic acrylic with hydrophobic properties. Further animal and in vivo studies are required to support the findings of this study.

  3. Corneal edema and permanent blue discoloration of a silicone intraocular lens by methylene blue.

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    Stevens, Scott; Werner, Liliana; Mamalis, Nick

    2007-01-01

    To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye. A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion. The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations. This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.

  4. Antireflection coatings for intraocular lenses of sapphire and fianite

    Energy Technology Data Exchange (ETDEWEB)

    Babin, A.A.; Konoplev, Yu.N.; Mamaev, Yu.A. [Inst. of Applied Physics, Nizhnii Novgorod (Russian Federation)] [and others

    1995-10-01

    Broadband antireflection coatings for intraocular lenses of sapphire and fianite are calculated and implemented practically. Their residual reflectance in the liquid with a refracting index of 1.336 is below 0.2% from each face virtually over the entire visible region. 7 refs., 2 figs., 2 tabs.

  5. Straylight from glistenings in intraocular lenses : In vitro study

    NARCIS (Netherlands)

    Łabuz, Grzegorz; Reus, Nicolaas J; van den Berg, Thomas J T P

    PURPOSE: To assess light scattering from intraocular lenses (IOLs) with different numbers of laboratory-induced glistenings and create a model for predicting glistening effects on straylight. SETTING: Rotterdam Ophthalmic Institute, Rotterdam, the Netherlands. DESIGN: Experimental study. METHODS:

  6. Effect of cefuroxime and moxifloxacin on Staphylococcus epidermidis adherence to intraocular lenses.

    Science.gov (United States)

    Karadağ, Serhat; Ozkan, Berna; Karabaş, V Levent; Alintaş, Ozgül; Yumuk, Zeki; Cağlar, Yusuf

    2009-12-01

    To investigate and compare the effect of cefuroxime and moxifloxacin on adhesion of Staphylococcus epidermidis to intraocular lenses (IOLs). Experimental study. The 3-pieced hydrophobic acrylic lenses were contaminated with S. epidermidis (American Type Culture Collection 35983) solutions containing 108 colony-forming units. IOLs were inoculated into test tubes containing tryptic soy broth after being held in antibiotic solutions for 15 minutes. Sonication and vortex procedures were performed in order to remove all the remaining bacteria. From each tube 10 microL and 100 microL was taken and inoculated into sheep blood agar. The colonies were counted overnight. The statistical analyses were made using one-way ANOVA, Turkey Honestly Significant Differences test (HSD) and independent t tests, and a p value less than 0.05 was considered statistically significant. Overall, the mean numbers of colony-forming units on the lenses that were held in control, cefuroxime, moxifloxacin 0.5 mg/0.1 mL and moxifloxacin 0.1 mg/0.1 mL solutions were 1398 (SE 10.01 x 10(3)), 29.9 (SE 1.16 x 10(3)), 0.23 (SD 0.04 x 10(3)), and 0.41 (SD 0.05 x 10(3)), respectively. The evaluation using one-way ANOVA and Turkey HSD tests revealed significant statistical differences among the groups (p = 0.000). The evaluation using independent t tests revealed significant statistical differences between the 2 moxifloxacin groups (p < 0.05). Our results suggest that moxifloxacin and cefuroxime significantly inhibit bacterial adherence to IOLs. The effect of moxifloxacin on inhibition of bacterial adherence was significantly greater than that of cefuroxime. For this reason moxifloxacin might be considered as a better prophylactic agent.

  7. Optimizing outcomes with multifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gitansha Shreyas Sachdev

    2017-01-01

    Full Text Available Modern day cataract surgery is evolving from a visual restorative to a refractive procedure. The advent of multifocal intraocular lenses (MFIOLs allows greater spectacle independence and increased quality of life postoperatively. Since the inception in 1980s, MFIOLs have undergone various technical advancements including trifocal and extended depth of vision implants more recently. A thorough preoperative workup including the patients' visual needs and inherent ocular anatomy allows us to achieve superior outcomes. This review offers a comprehensive overview of the various types of MFIOLs and principles of optimizing outcomes through a comprehensive preoperative screening and management of postoperative complications.

  8. Professor Peter Choyce: an early pioneer of intraocular lenses and corneal/refractive surgery.

    Science.gov (United States)

    Pandey, Suresh K; Apple, David J

    2005-06-01

    Professor Peter Choyce, FRCS, DOMS, MS, was one of the pioneers of intraocular lens implant surgery. He developed an interest in artificial lens implantation following cataract surgery, a procedure that was widely criticized by the ophthalmic establishment in the UK, Europe, North America and other countries. Owing to the opposition to the intraocular lenses, Peter Choyce together with Sir Harold Ridley co-founded the International Intraocular Implant Club in 1966, which was responsible for the gradual acceptance of artificial lens implantation. Peter Choyce developed several models of intraocular lens, but did not patent the majority of them. The Choyce Mark IX, manufactured by Rayner Intraocular Lenses, became the first US Food and Drug Administration-approved intraocular lens in 1981. A review of Peter Choyce's record confirms a significant number of original innovations in the field of anterior segment surgery, including many procedures taken for granted today, but not associated with his name. These include early work on both kerato- and intraocular lens-refractive procedures, keratoprosthesis, pioneering paediatric implant procedures and others. Unfortunately his tenacious adherence to anterior chamber lens technology, while in general clinically sound, caused many to question his influence and hence he remained poorly understood even until after his death. He passed away on 8 August 2001 after a long fight with colon cancer. In this article, we provide evidence and elaborate Peter Choyce's accomplishments, which places him as one of the most innovative ophthalmologist in his surgical field in the twentieth century.

  9. Single-suture scleral fixation of subluxated foldable intraocular lenses.

    Science.gov (United States)

    Yarangumeli, Alper; Alp, Mehmet Numan; Kural, Gulcan

    2012-01-01

    To evaluate the results of single-suture scleral fixation of subluxated foldable intraocular lenses (IOL) in eyes with sufficient residual capsular support. The results of IOL repositioning by single-suture scleral fixation in 6 eyes of 6 patients with IOL subluxation were included. All subluxated IOLs were single-piece hydrophilic acrylic. Subluxation resulted from posterior capsule tears in 3 eyes, zonular dialyses in 2 eyes, and zonular dialysis with a capsulorhexis tear in 1 eye. A similar technique was used in all eyes in which one haptic was externalized through a superior clear corneal incision and tied with a Pair-PAK 10-0 polypropylene suture, and was finally retracted and fixated behind the iris close to the ciliary sulcus at the 12:00 meridian. All patients were followed up for at least 6 months. Best-corrected visual acuities ranged between finger counting and 20/70 (mean logMAR 1.02±0.64) preoperatively, and between 20/100 and 20/20 (mean logMAR 0.22±0.26) at the final postoperative visit. All IOLs remained centered and no significant postoperative complications were encountered except for an IOL tilt which resulted in a considerable oblique astigmatism in one eye. Subluxated foldable IOLs may safely be repositioned and secured with a single scleral fixation suture in selected cases with adequate amount of capsular remnants.

  10. Toric Intraocular Lenses in the Correction of Astigmatism During Cataract Surgery

    DEFF Research Database (Denmark)

    Kessel, Line; Andresen, Jens; Tendal, Britta

    2016-01-01

    TOPIC: We performed a systematic review and meta-analysis to evaluate the benefit and harms associated with implantation of toric intraocular lenses (IOLs) during cataract surgery. Outcomes were postoperative uncorrected distance visual acuity (UCDVA) and distance spectacle independence. Harms were...

  11. A simple technique of intraocular lenses explantation for single-piece foldable lenses

    Directory of Open Access Journals (Sweden)

    Arup Bhaumik

    2017-01-01

    Full Text Available Foldable intraocular lenses (IOLs are most commonly used in modern-day cataract surgery. Explantation of these IOLs is not frequently encountered, but sometimes extreme situations may demand the same. Commonly explantation is achieved by bisecting the IOL inside the anterior chamber with a cutter and delivering the pieces out one by one. This may require corneal wound extension with associated damage and endothelial loss leading to visual deterioration. We devised a simple, innovative IOL explantation technique utilizing a modified Alcon A cartridge and snare. This can successfully refold the IOL to be explanted inside the eye and deliver it out through the same wound. The device has limitations with very thick optic lenses, multipiece, and silicon IOLs. In conclusion, we describe a simple, innovative, and reproducible technique to explant almost any single piece IOL without compromising the original surgery and yielding very satisfactory outcomes.

  12. A study of patient satisfaction after cataract surgery with implantation of different types of intraocular lenses

    Directory of Open Access Journals (Sweden)

    Wei Ching-Kuo

    2012-10-01

    Full Text Available Abstract Background The implementation of capitated payment has driven medical institutions through developing balance billing for medical services. By exploring the patients’ decision-making factors on different self-pay items, a reference for the pricing and sales strategy for the related products can be formed. The major purposes of this study were to analyze the determinants of preoperative selection and postoperative satisfaction with implantation of different types of intraocular lenses in cataract surgery. Methods This cross-sectional study consisted of 127 patients that were 50 years of age and older, and who had phacoemulsification with intraocular lens implantation in both eyes. Data were collected by using a structured questionnaire. The following parameters were measured: access to medical care, attitude towards receiving medical products at one’s own expense, overall patient satisfaction and postoperative visual clarity. Results The results showed that the patient’s gender, educational level and economic status influenced the type of intraocular lens chosen. Patients in the insurance group cared about access to medical care, and patients in the balance billing group cared about product differentiation. ANOVA results showed no statistically significant differences in the overall satisfaction of the patients among the groups with different types of intraocular lenses. Patients that received cataract surgery with implantation of multifocal intraocular lenses had better vision when trying to view smaller objects and when looking at objects under strong light. Conclusions Manufacturers should increase the number of differences between their products, and health care providers can then recommend the appropriate intraocular lens in accordance with the needs or demands of their patients, and also by keeping in mind the financial constraints of their patients.

  13. A study of patient satisfaction after cataract surgery with implantation of different types of intraocular lenses.

    Science.gov (United States)

    Wei, Ching-Kuo; Wang, Shun-Mu; Lin, Jen-Chieh

    2012-10-29

    The implementation of capitated payment has driven medical institutions through developing balance billing for medical services. By exploring the patients' decision-making factors on different self-pay items, a reference for the pricing and sales strategy for the related products can be formed. The major purposes of this study were to analyze the determinants of preoperative selection and postoperative satisfaction with implantation of different types of intraocular lenses in cataract surgery. This cross-sectional study consisted of 127 patients that were 50 years of age and older, and who had phacoemulsification with intraocular lens implantation in both eyes. Data were collected by using a structured questionnaire. The following parameters were measured: access to medical care, attitude towards receiving medical products at one's own expense, overall patient satisfaction and postoperative visual clarity. The results showed that the patient's gender, educational level and economic status influenced the type of intraocular lens chosen. Patients in the insurance group cared about access to medical care, and patients in the balance billing group cared about product differentiation. ANOVA results showed no statistically significant differences in the overall satisfaction of the patients among the groups with different types of intraocular lenses. Patients that received cataract surgery with implantation of multifocal intraocular lenses had better vision when trying to view smaller objects and when looking at objects under strong light. Manufacturers should increase the number of differences between their products, and health care providers can then recommend the appropriate intraocular lens in accordance with the needs or demands of their patients, and also by keeping in mind the financial constraints of their patients.

  14. Evaluation of Different Power of Near Addition in Two Different Multifocal Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Ugur Unsal

    2016-01-01

    Full Text Available Purpose. To compare near, intermediate, and distance vision and quality of vision, when refractive rotational multifocal intraocular lenses with 3.0 diopters or diffractive multifocal intraocular lenses with 2.5 diopters near addition are implanted. Methods. 41 eyes of 41 patients in whom rotational +3.0 diopters near addition IOLs were implanted and 30 eyes of 30 patients in whom diffractive +2.5 diopters near addition IOLs were implanted after cataract surgery were reviewed. Uncorrected and corrected distance visual acuity, intermediate visual acuity, near visual acuity, and patient satisfaction were evaluated 6 months later. Results. The corrected and uncorrected distance visual acuity were the same between both groups (p=0.50 and p=0.509, resp.. The uncorrected intermediate and corrected intermediate and near vision acuities were better in the +2.5 near vision added intraocular lens implanted group (p=0.049, p=0.005, and p=0.001, resp. and the uncorrected near vision acuity was better in the +3.0 near vision added intraocular lens implanted group (p=0.001. The patient satisfactions of both groups were similar. Conclusion. The +2.5 diopters near addition could be a better choice in younger patients with more distance and intermediate visual requirements (driving, outdoor activities, whereas the + 3.0 diopters should be considered for patients with more near vision correction (reading.

  15. Mechanical properties of intra-ocular lenses

    Science.gov (United States)

    Ehrmann, Klaus; Kim, Eon; Parel, Jean-Marie

    2008-02-01

    Cataract surgery usually involves the replacement of the natural crystalline lens with a rigid or foldable intraocular lens to restore clear vision for the patient. While great efforts have been placed on optimising the shape and optical characteristics of IOLs, little is know about the mechanical properties of these devices and how they interact with the capsular bag once implanted. Mechanical properties measurements were performed on 8 of the most commonly implanted IOLs using a custom build micro tensometer. Measurement data will be presented for the stiffness of the haptic elements, the buckling resistance of foldable IOLs, the dynamic behaviour of the different lens materials and the axial compressibility. The biggest difference between the lens types was found between one-piece and 3-piece lenses with respect to the flexibility of the haptic elements

  16. Moxifloxacin superior to cefuroxime in reducing bacterial adhesion of Staphylococcus epidermidis on hydrophobic intraocular lenses.

    Science.gov (United States)

    Benbouzid, Fathalah; Kodjikian, Laurent; Hartmann, Daniel; Renaud, François; Baillif, Stéphanie

    2016-02-01

    To compare the anti-adhesive effect of cefuroxime and moxifloxacin on the primary attachment phase of Staphylococcus epidermidis on hydrophobic acrylic intraocular lenses (IOLs). Forty hydrophobic acrylic IOLs were used. Two groups of IOLs were soaked in a moxifloxacin (Mox-T1: 0.5 mg/0.1 ml) or a cefuroxime (Cef-T1: cefuroxime 1 mg/0.1 ml) solution before incubation in a S. epidermidis bacterial suspension. Two other groups were incubated in the bacterial suspension before antibiotics (Cef-T2 and Mox-T2) were added. The control group (Ctrl) consisted of IOLs incubated in the bacterial suspension. After incubation, IOLs were sonicated and vortexed. The resultant suspension was spread over a nutritive agar plate. Bacterial colonies were counted after 24 hr of incubation. Mean number of colony-forming units per IOL was Cef-T1: 184 × 10(3) (SE: 5.24; SD: 28.21), Cef-T2: 117 × 10(3) (SE: 5.74; SD: 30.37), Mox-T1: 1.27 × 10(3) (SE: 0.12; SD: 0.61), Mox-T2: 25 × 10(3) (SE:1.98; SD: 9.72) and Ctrl: 361 × 10(3) (SE: 26.9; SD: 107.6). The number of adhering bacteria did not vary whether cefuroxime was added before or after IOL incubation in the bacterial suspension (p = 0.132). Moxifloxacin was more effective in reducing the number of adhering bacteria when used before IOL incubation (p < 0.001). Overall for T1 and T2, moxifloxacin was more effective than cefuroxime in reducing bacterial adhesion on IOLs (p < 0.001). Moxifloxacin and cefuroxime significantly reduced S. epidermidis adhesion on hydrophobic acrylic IOLs. The anti-adhesive effect was superior with moxifloxacin. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  17. Pigment dispersion syndrome and pigmentary glaucoma after secondary sulcus transscleral fixation of single-piece foldable posterior chamber intraocular lenses in Chinese aphakic patients.

    Science.gov (United States)

    Tong, Nianting; Liu, Fuling; Zhang, Ting; Wang, Liangyu; Zhou, Zhanyu; Gong, Huimin; Yuan, Fuxiang

    2017-05-01

    To describe secondary pigment dispersion syndrome (PDS) and pigmentary glaucoma after secondary sulcus transscleral fixation of 1-piece hydrophobic acrylic foldable posterior chamber intraocular lenses (PC IOLs) in aphakic patients in a Chinese population. Department of Ophthalmology, Qingdao Municipal Hospital, Qingdao, China. Retrospective case series. This chart review included eyes that had secondary sulcus transscleral fixation of a 1-piece hydrophobic acrylic foldable PC IOL (Tecnis ZCB00) between March 2011 and March 2014. The patients' demographic data, clinical data, postoperative complications, intervals between initial surgery and the onset of PDS, pigmentary glaucoma occurrences, and findings on slitlamp biomicroscopy, gonioscopy, and ultrasound biomicroscopy (UBM) were recorded. The study comprised 23 consecutive eyes of 21 patients. Seventeen eyes of 16 patients were diagnosed with PDS, and 7 eyes of 6 patients were diagnosed with pigmentary glaucoma. The slitlamp examination and UBM showed that the location between the IOL optic and the posterior surface of the iris was very close. Slitlamp examination of the anterior chamber angle using a gonioscope showed dense pigment deposition on the IOL surfaces. A reverse pupillary block was found in 10 eyes of 9 patients. Other postoperative complications included intraocular hemorrhage, pupillary capture of the IOL optic, IOL tilt, IOL decentration, IOL dislocation, and suture erosion. The 1-piece hydrophobic acrylic foldable PC IOL was not suitable for sulcus transscleral fixation because of a high incidence of PDS and pigmentary glaucoma after surgery in a Chinese population. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. Spectral properties of common intraocular lens (IOL) types

    Science.gov (United States)

    Milne, Peter J.; Chapon, Pascal F.; Hamaoui, Marie; Parel, Jean-Marie A.; Clayman, H.; Rol, Pascal O.

    1999-06-01

    Currently over 50 kinds of intraocular lenses (IOLs) are approved for patient use in the treatment of cataracts and ametropia. These lenses are manufactured from at least 2 kinds of silicones as well as several kinds of acrylic polymers including polyHEMA, Poly HOXEMA, a range of polymethacrylate and polyacrylate formulations. We sought to measure spectral transmission curves of a range of IOLS in the UV-visible and near IR spectral regions in order to better characterize their optical properties and to provide a baseline from which to assess their alteration following implantation over time. Consideration of how this may best be achieved are discussed. The variable ability of both explained IOLs and some samples from a range of manufacturers to block UV wavelengths is commented upon.

  19. [Comparison of four MICS intraocular lenses regarding their rates of neodymium:YAG laser capsulotomy].

    Science.gov (United States)

    Spyridaki, M; Höh, H

    2010-03-01

    The aim of this study was to evaluate the incidence of posterior capsule opacification up to 50 months following 1.7-mm bimanual MICS-cataract surgery. Bimanual MICS cataract surgery was performed in 197 eyes (135 patients) via two 1.7-mm corneal incisions. Four MICS acrylic foldable IOLs were implanted: AcriSmart 48S-5, n = 54 (Acritec GmbH, Hennigsdorf, now AT.Smart 48S Carl-Zeiss-Meditec, AG, Jena, Germany), ThinLens UltraChoice 1.0, n = 53 (Technomed GmbH, Baesweiler, Germany), AcriFlex 46, n = 41 und AcriFlex 48 CSE, n = 7 (Acrimed GmbH, Berlin, now: Lentis L-303, Oculentis GmbH, Berlin, Germany) and CareFlex, n = 43 (w2o Medizintechnik AG, Bruchsal, Germany). Statistical analysis was performed using the Kaplan-Meier technique. High levels of completeness of follow-up rates were: ThinLens 96%, CareFlex 100%, AcriSmart 93%, AcriFlex 92%. The capsulotomy rate was 43.13% for ThinLens within a mean/max. follow-up period of 801/1131 days, 34.88% for CareFlex (565/872 days), 40% for AcriSmart (988/1506 days) and 15.91% for AcriFlex (728/975 days). By limiting the follow-up period to a comparable maximum of 850 days for all four IOLs, our capsulotomy rates were as follows: ThinLens 33.33%, CareFlex 32.56 %, AcriSmart 20.0% and AcriFlex 11.36%. MICS IOLs have higher capsulotomy rates than hydrophobic acrylic lenses and sharp-edged silicone lenses. In literature comparisons MICS-IOLs do not exceed the variance levels of capsulotomy rates of PMMA, hydrophilic acrylic and silicone lenses without sharp edges. Cases of decentration or luxation of MICS-IOLs following Neodym:YAG laser capsulotomy were not detected. Capsulotomy frequency with the CareFlex was statistically significantly higher in comparison to the AcriSmart (Log Rank Mantel Cox Test, p = 0.007) and AcriFlex (log rank Mantel Cox test, p = 0.002). Capsulotomy rates observed varied for the four MICS-IOL-types tested. The posterior capsule opacification frequency of the two best MICS-IOLs (AcriFlex, Acri

  20. Effect of gamma radiation on the optical properties of intraocular lenses

    International Nuclear Information System (INIS)

    Naguib, N.I.

    2006-01-01

    The effect of gamma rays in the range of doses up to 150 gray on optical and thermal properties of the intraocular lenses (IOL) made of polymethyl methacrylate (PMMA) was studied. Thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC) have been performed to study the effect of gamma irradiation on the IOL. The results indicate that irradiation up to 150 Gy did not affect greatly the optical and thermal properties of the investigated IOL

  1. Effect of transscleral neodymium: YAG cyclophotocoagulation on intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Blomquist, P.H.; Gross, R.L.; Koch, D.D. (Baylor College of Medicine, Houston, TX (USA))

    1990-03-01

    A neodymium: YAG laser operating in the thermal mode was used to irradiate isolated intraocular lenses (IOLs) and to perform transscleral cyclophotocoagulation on pseudophakic autopsy eyes to investigate the potential damage to IOL haptics such irradiation may cause. In the isolated IOLs, 70 mJ of energy deformed and partially melted both polymethylmethacrylate (PMMA) and polypropylene haptics. One of the capsular-fixated PC-IOL haptics in an autopsy eye partially melted when irradiated with the maximum energy level (8.8 J), with the aiming beam focused 1 mm posterior to the limbus and maximal posterior focus offset.

  2. Intraocular lenses and clinical treatment in paediatric cataract

    Directory of Open Access Journals (Sweden)

    Camila Ribeiro Koch Pena

    2015-06-01

    Full Text Available Pediatric cataract is the most common treatable cause of blindness in children. Prevalence, etiology and morphology vary with the socioeconomic development. The treatment goal is to reduce amblyopia, being difficult management especially in unilateral cases. The decision on aphakia or primary intraocular lens should be individualized as well as correction with contact lens or spectacles. The intraocular lens single-piece hydrophobic acrylic are the most implanted in children and the preferably is in the capsular bag. The Sanders-Retzlaff-Kraff theoretic (SRK/T stressing that is described as more predictable, following Holladay I and SRK II and the recommendation is to under correction +6.0 or +8.0 dioptrias expecting the growth of the eye. The posterior capsule opacity is the most frequent complication and varies with the material choice of the lens. Glaucoma is the most serious postoperative complication and depends on the timing of the surgery, primary lens implantation and time of post surgical follow-up. The adherence to occlusion therapy with patching is critical to the visual prognosis and is determined by the child’s age and laterality of the cataract. There was significant improvement in the surgery and in IOLs, however the final visual prognosis is still not desirable.

  3. Incidência de opacificação de cápsula posterior em pacientes submetidos à facoemulsificação e implante de lentes intra-oculares acrílicas hidrofílicas expansíveis Incidence of posterior capsule opacification in patients submitted to phacoemulsification and expandable acrylic intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Hilton Arcoverde Gonçalves de Medeiros

    2006-06-01

    Full Text Available OBJETIVO: Avaliar prospectivamente os resultados das lentes intra-oculares de polímeros expansíveis implantadas em pacientes submetidos à facoemulsificação, quanto à incidência de opacificação de cápsula posterior, levando em consideração a biocompatibilidade das lentes expansíveis. MÉTODOS: O grupo de estudo foi composto por 830 pacientes, 1.200 olhos, que foram submetidos a facoemulsificação, utilizando a mesma técnica, variando-se apenas o diâmetro da capsulorrexe, pelo mesmo cirurgião, no período de 1998 a 2002, com implante de lente intra-ocular hidrofílica expansível. O acompanhamento médio foi de 2,4 anos, variando de seis meses a quatro anos. RESULTADOS: O número total de opacificação de cápsula posterior foi de 54 casos. CONCLUSÃO: A incidência de opacificação de cápsula posterior encontrada no grupo foi de 4,6%.PURPOSE: To evaluate prospectively the results of expandable acrylic intraocular lenses in patients submitted to phacoemulsification as regard posterior capsule opacification. METHODS: The study group consisted of 830 patients, 1,200 eyes that underwent phacoemulsification from 1998 to 2002, by the same surgeon, using the same technique but with different diameters of capsulorrhexis, with expandable hydrophilic acrylic intraocular lens implantation. The mean follow-up was 2.4 years, ranging from 6 months to 4 years. RESULTS: The total number of posterior capsule opacification was 54 cases. CONCLUSIONS: The incidence of posterior capsule opacification was 4.6% in these patients.

  4. Anterior capsular support for posterior chamber intraocular lenses following vitreous loss in endocapsular surgery

    Directory of Open Access Journals (Sweden)

    Jacob Pushpa

    1993-01-01

    Full Text Available We used anterior capsular support for posterior chamber intraocular lenses (PC IOLs in fourteen eyes with large posterior capsular ruptures. An endocapsular technique preserved the anterior capsule and facilitated implantation. With a median follow up of 8.5 months, all patients had a visual acuity of 6/9 or better. One lens was lost in the vitreous and one patient had a clinically significant cystoid macular edema. In the event of a posterior capsular rupture we suggest this technique as an alternative to anterior chamber or scleral-fixated lenses

  5. Use of hydroxypropylmethylcellulose 2% for removing adherent silicone oil from silicone intraocular lenses

    OpenAIRE

    Wong , S Chien; Ramkissoon , Yashin D; Lopez , Mauricio; Page , Kristopher; Parkin , Ivan P; Sullivan , Paul M

    2009-01-01

    Abstract Background / aims: To investigate the effect of hydroxypropylmethylcellulose (HPMC) on the physical interaction (contact angle) between silicone oil and a silicone intraocular lens (IOL). Methods: In vitro experiments were performed, to determine the effect of HPMC (0.5%, 1% or 2%), with or without an additional simple mechanical manoeuvre, on the contact angle of silicone oil at the surface of both silicone and acrylic (control) IOLs. A balanced salt solu...

  6. [Scheimpflug photography for the examination of phakic intraocular lenses].

    Science.gov (United States)

    Baumeister, M

    2014-10-01

    High myopia phakic intraocular lenses (IOL) have become an established means of surgical correction for high ametropia. Scheimpflug photography is one of the methods which are frequently applied for postoperative examination of the implants. Results from published studies employing Scheimpflug photography for examination of anterior chamber angle-fixated, iris-fixated and sulcus-fixated phakic IOLs were evaluated. In several published studies Scheimpflug photography was used to examine the position of the implant and opacification of the crystalline lens. The results provided valuable evidence for the improvement of phakic IOL design. Scheimpflug photography offers an easy to use, rapid non-contact examination of phakic IOLs.

  7. Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children

    OpenAIRE

    Das, Pranab; Ram, Jagat; Brar, Gagandeep Singh; Dogra, Mangat R

    2009-01-01

    Purpose : To evaluate the outcome of intraocular lens (IOL) implantation using capsular tension ring (CTR) in subluxated crystalline or cataractous lenses in children. Setting : Tertiary care setting Materials and Methods : We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90° up to 210° after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior ...

  8. A Rapid and Convenient Procedure to Evaluate Optical Performance of Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Frank Schaeffel

    2014-09-01

    Full Text Available A new portable lens scanner was developed and tested for measuring focal lengths and relative contrast transfer of mono- and multifocal intraocular lenses (IOLs. A photograph of a natural scene was imaged in white light through an IOL in a water-filled cuvette, with their +21D base power largely neutralized by a −20D trial lens, using a USB monochrome video camera that could be focused via a laptop-controlled stepping motor from −8.5 to + 8.0D. The output of 10000 ON-OFF antagonistic “receptive fields” measuring the video image with adjustable diameter was continuously recorded by custom written software to quantify focus and relative contrast. Six monofocal and four multifocal IOLs, as well as two radial refractive gradient (RRG lenses were measured. After calibration with trial lenses the optical powers and relative contrast transfer of mono- and multifocal IOLs were readily measured. Refractive power profiles measured in RRG lenses closely matched data obtained from the manufacturer. The lens scanner uses a rapidly operating procedure, is portable and can be used to verify positions of the focal planes of mono- and multifocal IOLs in less than 3 s.

  9. [Effect of intraocular pressure measurement through therapeutic soft contact lenses by noncontact tonometer].

    Science.gov (United States)

    Sugimoto-Takeuchi, R; Yamamoto, R; Kuwayama, Y; Kinoshita, S

    1991-09-01

    The measurement of intraocular pressure (IOP) was compared with and without soft contact lenses by a non-contact tonometer. The soft contact lenses examined were Plano-T and Plano-B4 therapeutic contact lenses and Breath-O refractive lens. Twenty-nine eyes of 18 patients with an IOP ranging from 9 to 48mmHg were studied. The measurements of IOP were 19.7 +/- 8.6mmHg with Plano-T and 18.9 +/- 9.2mmHg with Plano-B4. Both numbers were not statistically different, when compared with controls (19.3 +/- 9.8mmHg without lens). There was, however, a significant difference significant difference with (44.7 +/- 10.7mmHg) and without the Breath-O (p less than 0.01). The results suggest that accurate IOP measurements can be obtained through therapeutic soft contact lens by a non-contact tonometer.

  10. Combined pars plana lensectomy-vitrectomy with open-loop flexible anterior chamber intraocular lens (AC IOL) implantation for subluxated lenses.

    Science.gov (United States)

    Kazemi, S; Wirostko, W J; Sinha, S; Mieler, W F; Koenig, S B; Sheth, B P

    2000-01-01

    To review our experience with combined pars plana lensectomy-vitrectomy and open-loop flexible anterior chamber intraocular lens (AC IOL) implantation for managing subluxated crystalline lenses. Retrospective review of 36 consecutive eyes (28 patients), all of which had subluxated crystalline lenses, managed by pars plana lensectomy-vitrectomy with insertion of an open-loop flexible AC IOL. The study was performed at the Medical College of Wisconsin, Milwaukee, over an 8-year period. An average preoperative visual acuity of 20/163 (range, 20/25 to hand motions) improved to 20/36 (range, 20/20 to 4/200) with surgery after a mean follow-up of 14 months (range, 1 to 59 months) (P IOL implantation appears to be an excellent technique for managing subluxated crystalline lenses. It is associated with a significant improvement in visual acuity (P subluxated lens through a limbal wound. Additionally, use of an AC IOL offers a simplified alternative to placement of a ciliary sulcus sutured posterior chamber intraocular lens (PC IOL).

  11. The effect of ionizing radiation on intraocular lenses

    International Nuclear Information System (INIS)

    Ellerin, Bruce E.; Nisce, Lourdes Z.; Roberts, Calvin W.; Thornell, Cliff; Sabbas, Albert; Wang Huili; Li, P. Mark; Nori, Dattatreyudu

    2001-01-01

    Background: The native crystalline lens is the principal shield against ultraviolet radiation (UV), damage to the human retina. Every year in the United States, more than one million patients undergo removal of the natural lens in the course of cataract surgery (phakectomy), at which time an intraocular lens (IOL) is placed in the lens capsule. The IOL thenceforth serves as the principal barrier to ultraviolet radiation over the life of the implant, potentially for decades. The synthetic organic molecules of which IOLs are composed offer little UV protection unless ultraviolet-absorbing chromophores are incorporated into the lens material during manufacture. However, chromophores are alkenes potentially subject to radiolytic degradation. It is unknown whether ionizing radiation at clinical doses (e.g., to the brain or in the head-and-neck region) affects the UV-absorbing capacity of chromophore-bearing IOLs and consequently exposes the retina to potentially chronic UV damage. In addition, the polymers of which IOLs are composed are themselves subject to radiation damage, which theoretically might result in optical distortion in the visible light range. Objective: To determine whether megavoltage photon ionizing radiation alters the absorption spectra of ultraviolet-shielding polymethylmethacrylate (PMMA) and organopolysiloxane (silicone) intraocular lenses (IOLs) in the UV (280 nm ≤ λ < 400 nm), visible (400 nm ≤ λ ≤ 700 nm), and low-end near-infrared (700 nm < λ ≤ 830 nm) ranges. Design: Prospective, nonrandomized trial of dose-paired IOL cohorts. Methods: Fourteen IOLs, seven of PMMA (Chiron 6842B) and seven of silicone (IOLAB L141U), were paired and examined for absorption spectra in 1-nm intervals over the range λ = 280-830 nm on a Cary 400 deuterium and quartz halogen source-lamp UV/visible spectrophotometer before and after undergoing megavoltage ionizing irradiation to doses of 2, 5, 10, 20, 40, 60, and 100 Gray, respectively. Because of

  12. Bilateral implantation of +2.5 D multifocal intraocular lens and contralateral implantation of +2.5 D and +3.0 D multifocal intraocular lenses: Clinical outcomes

    NARCIS (Netherlands)

    Nuijts, Rudy M. M. A.; Jonker, Soraya M. R.; Kaufer, Robert A.; Lapid-Gortzak, Ruth; Mendicute, Javier; Martinez, Cristina Peris; Schmickler, Stefanie; Kohnen, Thomas

    2016-01-01

    To assess the clinical visual outcomes of bilateral implantation of Restor +2.5 diopter (D) multifocal intraocular lenses (IOLs) and contralateral implantation of a Restor +2.5 D multifocal IOL in the dominant eye and Restor +3.0 D multifocal IOL in the fellow eye. Multicenter study at 8

  13. Intraocular pressure measurement with the noncontact tonometer through soft contact lenses.

    Science.gov (United States)

    Liu, Yi-Chun; Huang, Jehn-Yu; Wang, I-Jong; Hu, Fung-Rong; Hou, Yu-Chih

    2011-03-01

    To assess the accuracy of measuring intraocular pressure (IOP) through a soft contact lens (SCL) with different refractive powers using a noncontact tonometer (NCT). Thirty-two healthy adult volunteers free of glaucoma or corneal disease participated in this study. IOP was measured in the right eyes without SCLs and with different lens powers, from -3.0 to -12.0 D as measured by NCT. IOP of the left eyes was also measured, as an internal control. Corneal curvature was measured in both eyes using an autokeratometer. Sixteen volunteers wore one brand of SCL (group A) and the other 16 wore a different brand, with 2 different curvatures (groups B and C). Statistical data were analyzed by SPSS using the Wilcoxon signed rank test for comparison of IOP readings and multiple linear regression analysis for the relationship among power of contact lenses, corneal power, and difference in IOP measurements. The difference in mean IOP between eyes without lenses and those with lenses was statistically significant in lens with -6.0 D and below in all 3 groups. The decrease in IOP significantly correlated with the refractive power of contact lenses in all 3 groups. The difference in IOP measurements was influenced by the mean K in group A but not in group B or C. There was no statistically significant difference in the IOP measurements in the left eyes or in the mean K between the right and left eyes. IOP measurement through myopic SCLs by NCT may be inaccurate and tends toward underestimation, especially in high myopic lenses. A strong relationship exists between IOP reduction and myopic lens power.

  14. The effects of the modulus of the lens material on intraocular pressure measurement through soft contact lenses.

    Science.gov (United States)

    Boyraz, S; Güngör, I

    2013-09-01

    To investigate the effects of the modulus of the lens material on the intraocular pressure measurement using the Tono-Pen XL applanation tonometer through soft contact lenses. Thirty eyes of 15 patients with myopia were evaluated. Intraocular pressure (IOP) measurements were performed using Tono-Pen XL directly over cornea, and subsequently through three soft contact lenses made up of different lens materials. All were -3.00 diopter soft contact lenses: lotrafilcon A with a low water content (24%) and high modulus (1.4 MPa) (CL-I), balafilcon A with a moderate water content (36%) and moderate modulus (1.1 MPa) (CL-II), and vifilcon A with a moderate water content (55%) and low modulus (0.79 MPa) (CL-III). IOP measurements through contact lenses were compared with each other, and with direct corneal measurements. The mean age of the patients (11 males and 4 females) was 26.86±5.62 years. All measurements obtained through CLs were significantly higher than the direct corneal measurements. The measurements through CLs differed by 4.61±0.54 mmHg (P=0,001), 2.9±0.46 mmHg (P=0.001), and 1.94±0.51 mmHg (P=0,003) for CL-I, CL-II and CL-III, respectively. In the paired comparisons of measurements through CLs, all comparisons were significant except the comparison of measurements through CL-II and CL-III (P=0.128). IOP measurements through silicone-hydrogel contact lenses with a high modulus and low water content were higher compared to the other contact lenses. While measuring IOP through CLs, the clinicians should consider the effect of the lens material and the features of the device used.

  15. Anterior haptic flexing and in-the-bag subluxation of an accommodating intraocular lens due to excessive capsular bag contraction.

    Science.gov (United States)

    Kramer, Gregory D; Werner, Liliana; Neuhann, Tobias; Tetz, Manfred; Mamalis, Nick

    2015-09-01

    We describe the case of a patient who had cataract surgery with implantation of the hydrophilic acrylic Tetraflex accommodating intraocular lens (IOL), with subsequent development of capsulorhexis phimosis and in-the-bag IOL subluxation. Contraction of the capsular bag secondary to fibrosis resulted in significant anterior flexing of the lens haptic component. Explantation of the IOL-capsular bag complex was required 7 years after implantation. Histopathologic analysis demonstrated multiple areas of thick anterior subcapsular fibrosis. Pseudoexfoliative material was present throughout the surface of the lens capsule. Intraocular lenses manufactured from hydrophilic acrylic material are highly flexible and may be more susceptible to capsule contraction, even in the absence of predisposing ocular and systemic conditions. This case highlights the importance of developing guidelines regarding patient screening and selection for the appropriate use of accommodating and other highly flexible IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  16. In vivo chromatic aberration in eyes implanted with intraocular lenses.

    Science.gov (United States)

    Pérez-Merino, Pablo; Dorronsoro, Carlos; Llorente, Lourdes; Durán, Sonia; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2013-04-12

    To measure in vivo and objectively the monochromatic aberrations at different wavelengths, and the chromatic difference of focus between green and infrared wavelengths in eyes implanted with two models of intraocular lenses (IOL). EIGHTEEN EYES PARTICIPATED IN THIS STUDY: nine implanted with Tecnis ZB99 1-Piece acrylic IOL and nine implanted with AcrySof SN60WF IOL. A custom-developed laser ray tracing (LRT) aberrometer was used to measure the optical aberrations, at 532 nm and 785 nm wavelengths. The monochromatic wave aberrations were described using a fifth-order Zernike polynomial expansion. The chromatic difference of focus was estimated as the difference between the equivalent spherical errors corresponding to each wavelength. Wave aberration measurements were highly reproducible. Except for the defocus term, no significant differences in high order aberrations (HOA) were found between wavelengths. The average chromatic difference of focus was 0.46 ± 0.15 diopters (D) in the Tecnis group, and 0.75 ± 0.12 D in the AcrySof group, and the difference was statistically significant (P Chromatic difference of focus in the AcrySof group was not statistically significantly different from the Longitudinal chromatic aberration (LCA) previously reported in a phakic population (0.78 ± 0.16 D). The impact of LCA on retinal image quality (measured in terms of Strehl ratio) was drastically reduced when considering HOA and astigmatism in comparison with a diffraction-limited eye, yielding the differences in retinal image quality between Tecnis and AcrySof IOLs not significant. LRT aberrometry at different wavelengths is a reproducible technique to evaluate the chromatic difference of focus objectively in eyes implanted with IOLs. Replacement of the crystalline lens by the IOL did not increase chromatic difference of focus above that of phakic eyes in any of the groups. The AcrySof group showed chromatic difference of focus values very similar to physiological values in

  17. Effects of intraocular lenses with different diopters on chromatic aberrations in human eye models

    OpenAIRE

    Song, Hui; Yuan, Xiaoyong; Tang, Xin

    2016-01-01

    Background In this study, the effects of intraocular lenses (IOLs) with different diopters (D) on chromatic aberration were investigated in human eye models, and the influences of the central thickness of IOLs on chromatic aberration were compared. Methods A Liou-Brennan-based IOL eye model was constructed using ZEMAX optical design software. Spherical IOLs with different diopters (AR40e, AMO Company, USA) were implanted; modulation transfer function (MTF) values at 3?mm of pupil diameter and...

  18. [In Vitro Evaluation of the Optical Quality of Segmental Refractive Multifocal Intraocular Lenses].

    Science.gov (United States)

    Yildirim, Timur Mert; Auffarth, Gerd Uwe; Tandogan, Tamer; Liebing, Stephanie; Labuz, Grzegorz; Choi, Chul Young; Khoramnia, Ramin

    2017-11-08

    In customised patient care, it is important to know the optical quality of different intraocular lenses (IOL). In this study, the optical quality of three segmental intraocular lenses were compared. The LENTIS Comfort LS-313 MF15, LENTIS Mplus X LS-313 MF30 and LENTIS High Add IOL LS-313 MF80 (Oculentis, Berlin, Germany) with a far power of + 21 D were analysed at the optical bench OptiSpheric IOL PRO (Trioptics GmbH, Wedel, Germany). The lenses have almost the same optical design but differ in the power of the near segment. The MF15 has a + 1.5 D addition to improve vision in intermediate distances, the MF30 has a near addition of + 3 D and the MF80 has a near addition of + 8 D. The modulation transfer function area (MTFa) and the Strehl ratio were examined for apertures of 3 mm (photopic) and 4.5 mm (mesopic). The MTFa values for the far focus are 33.34/30.80/51.53 (MF15/MF30/MF80) with an aperture of 3 mm and 25.38/22.52/43.15 for 4.5 mm. The MTFa values for the intermediate focus are 29.85/16.21/6.25 for a 3 mm aperture and 23.92/8.05/3.08 for 4.5 mm. The MTFa values for the near focus are 9.75/21.49/33.12 for an aperture of 3 mm and 4.95/22.70/31.68 for 4.5 mm. The Strehl ratio of the far focus is 0.34/0.30/0.52 for an aperture of 3 mm and 0.24/0.22/0.43 for 4.5 mm. For the intermediate focus, the Strehl ratio is 0.30/0.17/0.07 for an aperture of 3 mm and 0.24/0.08/0.03 for 4.5 mm. The Strehl ratio of the near focus is 0.10/0.22/0.33 for an aperture of 3 mm and 0.05/0.23/0.32 for 4.5 mm. We confirmed that the addition influences the optical quality of segmental bifocal intraocular lenses. For the far focus, the results of the MF15 and MF30 are similar. In intermediate distances, the MF15 achieves the best results. For near distances, the MF30 achieves better optical values than the MF15. The lens MF80, which has been designed for patients with maculopathies, achieves good results for far and near distances. Georg

  19. The measurement of intraocular pressure over positive soft contact lenses by rebound tonometry.

    Science.gov (United States)

    Zeri, Fabrizio; De Cusatis, Mario; Lupelli, Luigi; Swann, Peter Graham

    2016-01-01

    To investigate if the accuracy of intraocular pressure (IOP) measurements using rebound tonometry over disposable hydrogel (etafilcon A) contact lenses (CL) is affected by the positive power of the CLs. The experimental group comprised 26 subjects, (8 male, 18 female). IOP measurements were undertaken on the subjects' right eyes in random order using a Rebound Tonometer (ICare). The CLs had powers of +2.00D and +6.00D. Measurements were taken over each contact lens and also before and after the CLs had been worn. The IOP measure obtained with both CLs was significantly lower compared to the value without CLs (t test; p<0.001) but no significant difference was found between the two powers of CLs. Rebound tonometry over positive hydrogel CLs leads to a certain degree of IOP underestimation. This result did not change for the two positive lenses used in the experiment, despite their large difference in power and therefore in lens thickness. Optometrists should bear this in mind when measuring IOP with the rebound tonometer over plus power contact lenses. Copyright © 2016 The Authors. Published by Elsevier Espana.. All rights reserved.

  20. Multifocal versus monofocal intraocular lenses after cataract extraction

    Directory of Open Access Journals (Sweden)

    Daniel Calladine

    Full Text Available BACKGROUND: Good unaided distance visual acuity is now a realistic expectation following cataract surgery and intraocular lens (IOL implantation. Near vision, however, still requires additional refractive power, usually in the form of reading glasses. Multiple optic (multifocal IOLs are available which claim to allow good vision at a range of distances. It is unclear whether this benefit outweighs the optical compromises inherent in multifocal IOLs. OBJECTIVES: The objective of this review was to assess the effects of multifocal IOLs, including effects on visual acuity, subjective visual satisfaction, spectacle dependence, glare and contrast sensitivity, compared to standard monofocal lenses in people undergoing cataract surgery. METHODS: Search methods: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register, The Cochrane Library 2012, Issue 2, MEDLINE (January 1946 to March 2012, EMBASE (January 1980 to March 2012, the metaRegister of Controlled Trials (mRCT (www.controlled-trials.com, ClinicalTrials.gov (www.clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP (www.who.int/ictrp/search/en. We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 6 March 2012. We searched the reference lists of relevant articles and contacted investigators of included studies and manufacturers of multifocal IOLs for information about additional published and unpublished studies. Selection criteria: All randomised controlled trials comparing a multifocal IOL of any type with a monofocal IOL as control were included. Both unilateral and bilateral implantation trials were included. Data collection and analysis: Two authors collected data and assessed trial quality. Where possible, we pooled data from the individual studies using a random-effects model, otherwise we tabulated data. MAIN RESULTS: Sixteen completed trials

  1. Postoperative diffuse opacification of a hydrophilic acrylic intraocular lens: analysis of an explant.

    Science.gov (United States)

    Cavallini, Gian Maria; Volante, Veronica; Campi, Luca; De Maria, Michele; Fornasari, Elisa; Urso, Giancarlo

    2017-06-14

    We describe the clinicopathological and ultrastructural features of an opaque single-piece hydrophilic acrylic intraocular lens (IOL) explanted from a patient. The main outcome of this report is the documentation of calcium deposits confirmed by surface analysis. The decrease in visual acuity was due to the opacification of the IOL. The opacification involved both the optic plate and the haptics. The analysis at the scansion electron microscope revealed that the opacity was caused by the deposition of calcium and phosphate within the lens optic and haptics. This is the first case about the opacification of an Oculentis L-313. The opacification was characterized by calcium and phosphate deposition probably due to a morphological alteration of the posterior surface of the IOL.

  2. Customized computer models of eyes with intraocular lenses.

    Science.gov (United States)

    Rosales, P; Marcos, S

    2007-03-05

    We compared experimental wave aberrations in pseudophakic eyes with aspheric intraocular lenses (IOLs) to simulate aberrations from numerical ray tracing on customized computer eye models using corneal topography, angle lambda, ocular biometry, IOL geometry, and IOL tilt and decentration measured on the same eyes. We found high correlations between real and simulated aberrations even for the eye with only the cornea, and these increased on average when the IOL geometry and position were included. Relevant individual aberrations were well predicted by the complete eye model. Corneal spherical aberration and horizontal coma were compensated by the IOL, and in 58.3% of the cases IOL tilt and decentration contributed to compensation of horizontal coma. We conclude that customized computer eye models are a good representation of real eyes with IOLs and allow understanding of the relative contribution of optical, geometrical and surgically-related factors to image quality. Corneal spherical aberration is reduced by aspheric IOLs, although other corneal high order aberrations are still a major contributor to total aberrations in pseudophakic eyes. Tilt and decentration of the IOLs represent a relatively minor contribution of the overall optical quality of the eye.

  3. Sutureless, Glueless, Scleral Fixation of Single-Piece and Toric Intraocular Lens: A Novel Technique

    Directory of Open Access Journals (Sweden)

    Aditya Kelkar

    2015-07-01

    Full Text Available Sutureless, glueless, scleral fixation of an intraocular lens is a known technique of fixing a lens in the scleral pockets. However, this technique is applied to single-piece and toric lenses instead of 3-piece lenses, allowing the advantage of the use of premium lenses in patients with poor capsular support. Favourable results without complications of pigment dispersion, iris transillumination defects, dysphotopsia, elevated intraocular pressure, intraocular hemorrhage and cystoid macular edema with a well-centered, stable intraocular lens have been observed in the 3-month postoperative period in both cases.

  4. Studies on Development of Polymeric Materials Using Gamma Irradiation for Contact and Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Pranshu Chhabra

    2009-01-01

    Full Text Available For the development of materials for contact lenses and intraocular lenses, the selection criteria is based on the (i capacity to absorb and retain water, (ii hydrophilicity and hydrophobicity, (iii refractive index and (iv hardness besides the other essential properties. Various monomers are being studied to develop suitable materials for such applications. Selection of suitable monomers that can be converted into optical materials of desired characteristics is the most essential step. In the present paper, an attempt has been made to develop suitable optical polymers based on 2-hydroxy ethyl methacrylate (HEMA, N-vinyl pyrrolidone (NVP, methyl methacrylate (MMA, methacrylic acid (MAA, and styrene. Compositions were prepared in such a way that polymers of varying hydrophilicity or hydrophobicity could be obtained keeping HEMA as the base (main monomer. For polymerization, gamma irradiation (Co-60 as a source was used. The results of the study showed that: (i an increase in NVP and MAA content brought in an increase in hydrophilicity of polymerized HEMA (pHEMA, while the addition of styrene and MMA decreased hydrophilicity of polymerized HEMA (pHEMA, (ii polymers for contact lenses with water retention capacity as high as >50 wt.% and as low as <10 wt% with varying content of suitable comonomers can be designed, (iii polymeric materials for contact lenses can be made by using radiation processing such as Co-60 and (iv a dose of 40 kGy was found to be ideal for purpose.

  5. Towards customized intraocular lenses

    NARCIS (Netherlands)

    de Jong, Tim

    2017-01-01

    In the eye there are two refractive components that make light focus on the retina and let you see: the cornea and the lens. When a eye develops cataract the lens becomes caractarous and is removed and replaced with a synthetic intraocular lens during a cataract surgery procedure. Although there was

  6. The effect of blue-blocking and neutral intraocular lenses on circadian photoentrainment and sleep one year after cataract surgery

    DEFF Research Database (Denmark)

    Brøndsted, Adam Elias; Haargaard, Birgitte; Sander, Birgit

    2017-01-01

    surgery with implantation of either a neutral or a blue-blocking intraocular lens (IOL). Main outcome was activation of the intrinsically photosensitive retinal ganglion cells (ipRGC) measured by chromatic pupillometry. The circadian rhythm was analysed by 24-hr melatonin profiles and actigraphy......PURPOSE: To compare the long-term effect on circadian photoentrainment and sleep in patients implanted with neutral and blue-blocking intraocular lenses 1 year after cataract surgery. METHODS: Randomized, controlled trial involving 67 patients with age-related cataract. Intervention was cataract...... compared with neutral IOLs. Cataract surgery improved the response of ipRGCs and sleep quality. However, the effect of cataract surgery on sleep quality may be unrelated to circadian photoentrainment....

  7. Management of subluxated capsular bag-fixated intraocular lenses using a capsular anchor.

    Science.gov (United States)

    Ton, Yokrat; Naftali, Modi; Gortzak, Ruth Lapid; Assia, Ehud I

    2016-05-01

    We describe the use of the capsular anchor (AssiAnchor) to manage a subluxated intraocular lens (IOL) in the capsular bag. The anchor comprises 2 prongs that hold the anterior lens capsule and a central rod that is sutured to the scleral wall, enabling centration of the IOL-capsular bag complex. Six pseudophakic patients presenting with subluxated posterior chamber IOLs in the capsular bag were operated on using the device. The anchor was used successfully in all cases, although in 2 cases only 1 prong was placed under the capsulorhexis edge. In 1 eye, 2 anchors were used 1 month apart following repeated traumatic zonular injury. The capsular bag holding the IOL remained centered and stable throughout the follow-up period. The anchoring device, which was originally designed to preserve the lens capsule and stabilize subluxated crystalline lenses, can also be used to treat subluxation of a capsular bag-fixated IOL. Dr. Assia is the inventor of the AssiAnchor, has a licensed patent of the anchor, and is consultant to Hanita Lenses. Dr. Lapid-Gortzak is a consultant to and speaker for Alcon Surgical, Inc., Hanita Lenses, Orca Surgical, and Sanoculis Ltd.; a speaker for Santen; and a consultant to Icon. Drs. Ton and Naftali have no financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Near-point string: Simple method to demonstrate anticipated near point for multifocal and accommodating intraocular lenses.

    Science.gov (United States)

    George, Monica C; Lazer, Zane P; George, David S

    2016-05-01

    We present a technique that uses a near-point string to demonstrate the anticipated near point of multifocal and accommodating intraocular lenses (IOLs). Beads are placed on the string at distances corresponding to the near points for diffractive and accommodating IOLs. The string is held up to the patient's eye to demonstrate where each of the IOLs is likely to provide the best near vision. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  9. Neodymium: YAG laser damage threshold. A comparison of injection-molded and lathe-cut polymethylmethacrylate intraocular lenses.

    Science.gov (United States)

    Wilson, S E; Brubaker, R F

    1987-01-01

    The possibility that injection-molded intraocular lenses (IOLs) with imperfections called iridescent clefts could have a decreased threshold to neodymium: YAG (Nd:YAG) laser-induced damage was investigated. Thresholds for Nd:YAG laser-induced damage were determined for injection-molded and lathe-cut polymethylmethacrylate lenses. When aimed at a membrane in contact with a posterior convex surface, the average thresholds were 0.96 +/- 0.18 mJ (Standard deviation [SD]) and 1.80 +/- 0.55 mJ, respectively. The difference was significant at P = 0.001. When injection-molding polymethylmethacrylate was used to make lathe-cut IOLs, very few iridescent clefts were present, and the threshold to Nd:YAG laser-induced damage was 0.94 +/- 0.25 mJ. Iridescent clefts are therefore produced during the injection-molding process but they do not lower the threshold to Nd:YAG laser-induced damage. Rather, the reduced threshold in injection-molded lenses is most probably a result of the polymethylmethacrylate used in their manufacture. Clinically, iridescent clefts in a lens suggest that it has been manufactured by an injection-molding process and that Nd:YAG laser posterior capsulotomy must be performed at the lowest possible energy level to avoid damage.

  10. Prótese intra-ocular de resina acrílica em cães e gatos Acrylic resin intraocular prosthesis in dogs and cats

    Directory of Open Access Journals (Sweden)

    S.C. Rahal

    2000-08-01

    Full Text Available Foram atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Unesp - Campus de Botucatu, 11 animais (oito cães e três gatos, com alterações oftálmicas unilaterais graves que levaram à perda total da função ocular (protrusão de globo com injúria nervosa e estrutural, perfurações de córnea com perda de conteúdo intra-ocular e endoftalmites, entre outras. Os animais, com idades entre dois meses e 10 anos, foram submetidos à evisceração e posterior inclusão de esfera de resina acrílica (metilmetacrilato na capa córneo-escleral ou escleral. As esferas foram previamente confeccionadas e esterilizadas por autoclavagem. No pós-operatório foram utilizados antiinflamatórios e antibioticoterapia tópica combinada ou não a sistêmica. O período de observação variou de 2 meses a 3 anos e os aspectos avaliados foram secreção ocular, blefarospasmo, sinais de desconforto e estética. Obtiveram-se resultados satisfatórios em oito casos. Concluiu-se que a resina acrílica pode ser uma alternativa para uso como inclusão em cavidade anoftálmica.Eleven animals (eight dogs and three cats, aged between two months and ten years were referred to the Veterinary Hospital of Faculty of Veterinary Medicine and Animal Science - Unesp, Botucatu, Brazil. These animals presented severe unilateral ophthalmic changes that lead to a total loss of ocular function, such as prolapsed eyes with nervous and structural injury, corneal damage with loss of intraocular contents or endophthalmitis among others. They were submitted to evisceration followed by the insertion of an acrylic resin prosthesis (methylmethacrylate in the corneoscleral or scleral shell. The spheres were previously made and sterilized by autoclave. The postoperative medical therapy included topical and systemic broad-spectrum antibiotics for seven days and anti-inflammatory drugs. The follow-up time varied from two months to three years. The evaluated

  11. Microscopic analysis of an opacified OFT CRYL® hydrophilic acrylic intraocular lens

    Directory of Open Access Journals (Sweden)

    Bruna Vieira Ventura

    Full Text Available ABSTRACT A 51-year-old patient underwent posterior vitrectomy with perfluoropropane gas injection, phacoemulsification, and implantation of an Oft Cryl® hydrophilic acrylic intraocular lens (IOL because of traumatic retinal detachment and cataract in the right eye. On the first postoperative day, gas was filling the anterior chamber because of patient's non-compliance in terms of head positioning, and was reabsorbed within one week. Eight months later, the patient returned complaining of a significant decrease in vision. IOL opacification was noticed by slit-lamp examination. The lens was explanted to undergo gross and light microscopic analysis. The lens was also stained with the alizarin red method for calcium identification. Light microscopic analysis confirmed the presence of granular deposits, densely distributed in an overall circular pattern in the central part of the lens optic. The granules stained positive for calcium. This is the first case of the opacification of this type of hydrophilic lens. Surgeons should be aware of this potential postoperative complication, and the use of hydrophilic IOLs should be avoided in procedures involving intracameral gas because of the risk of IOL opacification.

  12. Micro-Raman analysis of glisterings in intraocular lenses

    Science.gov (United States)

    Rusciano, G.; Martinez, A.; Pesce, G.; Zito, G.; Sasso, A.

    2017-06-01

    The phenomenon of inclusions or microvacuoles in intraocular lenses (IOL), often referred to glistenings due to their appearance when visualized in slit-lamp exams, is main cause of decreased visual in people after IOL implantation. For this reason, there is a huge request by the market of new polymers able to reduce, or even eliminate, the formation of such microvacuoles. In such frame, the use of advanced optical techniques, able to provide a deeper insight on the glistering formation, is strongly required. In particular, Raman spectroscopy (RS) is ideally suited for the analysis of polymers, due to its well-know sensitivity to highly polarizable chemical groups, commonly found in the polymer chains backbones. Moreover, the combination of RS with optical microscopy (Raman micro-spectroscopy) paves the way for real, information-rich chemical mapping of polymeric materials (Raman imaging). In this paper, we analyze the formation of microvacuoles in IOLs following a thermal treatment. In particular, we performed a chemical mapping of a single microvacuole, which allowed us to infer on its effective chemical composition. In order to investigate on the reversibility of glistenings formation, this analysis was repeated as function of time after thermal treatment, in different IOL environments. It turns out that this phenomenon is partially reversible, with an almost complete disappearance of microvacuoles in a dry environment.

  13. Aderência bacteriana in vitro a lentes intra-oculares de polimetilmetacrilato e de silicone In vitro bacterial adherence to silicone and polymetylmethacrylate intraocular lenses

    Directory of Open Access Journals (Sweden)

    Claudete Inês Locatelli

    2004-04-01

    Full Text Available OBJETIVOS: Verificar a aderência bacteriana a lentes intra-oculares de silicone e de polimetilmetacrilato como possível fator de risco no desenvolvimento de endoftalmite pós-operatória, utilizando-se um modelo in vitro com três microrganismos potencialmente patogênicos. MÉTODOS: As análises foram realizadas com cepas de Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis (amostra clínica e Pseudomonas aeruginosa ATCC 27853 incluindo a determinação de curvas de crescimento, testes para verificação de produção de cápsula, avaliação da hidrofobicidade, testes de aderência a diferentes materiais, microscopia óptica, microscopia eletrônica de varredura e microscopia de força atômica. RESULTADOS: A produção de cápsula e a aderência das três diferentes cepas não mostraram qualquer relação com a quantidade de microrganismos; em relação às lentes intra-oculares de polimetilmetacrilato e de silicone, não houve diferença estatisticamente significativa na aderência de S. aureus e S. epidermidis; P. aeruginosa foi o microrganismo mais aderente a ambos os materiais. A microscopia eletrônica de varredura confirmou estes achados em relação à aderência, ao peso que a microscopia de força atômica evidenciou a produção de biofilme pelas cepas de S. aureus, S. epidermidis e P. aeruginosa. CONCLUSÕES: Constatou-se, in vitro, que os materiais analisados não diferiram com relação à taxa de aderência bacteriana, porém, P. aeruginosa apresentou maior eficiência de adesão entre as bactérias testadas. Todas as cepas produziram biofilme. Silicone foi o material mais hidrofóbico, quando comparado ao polimetilmetacrilato.PURPOSE: To evaluate bacterial adherence to silicone and polymetylmethacrylate (PMMA intraocular lenses as a risk factor for postsurgery endophthalmitis by using an in vitro model with three potentially pathogenic microorganisms. METHODS: In vitro experiments were carried out with the

  14. Characteristics of the retinal images of the eye optical systems with implanted intraocular lenses

    Science.gov (United States)

    Siedlecki, Damian; Zając, Marek; Nowak, Jerzy

    2007-04-01

    Cataract, or opacity of crystalline lens in the human eye is one of the most frequent reasons of blindness nowadays. Removing the pathologically altered crystalline lens and replacing it with artificial implantable intraocular lens (IOL) is practically the only therapy in this illness. There exist a wide variety of artificial IOL types on the medical market, differing in their material and design (shape). In this paper six exemplary models of IOL's made of PMMA, acrylic and silicone are considered. The retinal image quality is analyzed numerically on the basis of Liou-Brennan eye model with these IOL's inserted. Chromatic aberration as well as polychromatic Point Spread Function and Modulation Transfer Function are calculated as most adequate image quality measures. The calculations made with Zemax TM software show the importance of chromatic aberration correction.

  15. 21 CFR 886.4300 - Intraocular lens guide.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device intended to be inserted into the eye during surgery to direct... lenses, the device is exempt from the premarket notification procedures in subpart E of part 807 of this...

  16. Surface modification of polymethyl methacrylate intraocular lenses by plasma for improvement of antithrombogenicity and transmittance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lihua; Wu Di; Chen Yashao; Wang Xiaoli; Zhao Guowei; Wan Haiyan [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, School of Chemistry and Materials Science, Chang' an South Road 199, Xi' an 710062 (China); Huang Changzheng [Able Eye Device Co. Ltd, Zhengzhou 450008 (China)

    2009-05-15

    To improve antithrombogenicity and reduce ultraviolet transmittance, polymethyl methacrylate intraocular lenses (PMMA IOLs) were pretreated with Ar plasma and combined with heparin (Hp), with polyglycol (PEG) and with both Hp and PEG in a plasma atmosphere. The resulting modified PMMA IOLs denoted as PEG-PMMA, Hp-PMMA and Hp-PEG-PMMA were characterized by attenuated total reflectance Fourier transfer infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis), contact angle (CA) and platelet adhesion experiments. The results indicated that Hp and PEG had been successfully immobilized onto the surfaces of PMMA IOLs. Antithrombogenicity was improved remarkably and ultraviolet transmittance was reduced as well.

  17. Comparison of hydrophobic and hydrophilic intraocular lens in preventing posterior capsule opacification after cataract surgery

    Science.gov (United States)

    Zhao, Yang; Yang, Ke; Li, Jiaxin; Huang, Yang; Zhu, Siquan

    2017-01-01

    Abstract Background: Posterior capsular opacification (PCO) is a common long-term complication of cataract surgery. Intraocular lens design and material have been implicated in influencing the development of PCO. This study evaluated the association of hydrophobic and hydrophilic intraocular lenses on preventing PCO. Methods: Medline, Cochrane, EMBASE, and Google Scholar databases were searched until August 3, 2016, using the following search terms: cataract, posterior capsule opacification, and intraocular lens. Eligible studies included randomized controlled trials (RCTs), retrospective, and cohort studies. Results: Eleven studies were included in the study with a total of 889 eyes/patients. The overall analysis revealed that hydrophobic intraocular lenses were associated with lower Nd:YAG laser capsulotomy rates than hydrophilic lenses [odds ratio (OR) = 0.38, 95% confidence interval (95% CI) = 0.16–0.91, P = .029]. Hydrophobic intraocular lenses were also associated with lower subjective PCO score (diff. in means: −1.32, 95% CI = −2.39 to −0.25, P = .015) and estimated PCO score (diff. in means: −2.23; 95% CI, −3.80 to −0.68, P = .005) as compared with hydrophilic lenses. Objective PCO score was similar between lens types. (diff. in means: −0.075; 95% CI, −0.18 to 0.035; P = .182). Pooled analysis found that visual acuity was similar between hydrophobic and hydrophilic intraocular lenses (diff. in means: −0.016; 95% CI, −0.041 to 0.009, P = .208). Conclusion: In general, PCO scores and the rate of Nd:YAG laser capsulotomy were influenced by intraocular lens biomaterial. Lens made of hydrophobic biomaterial were overall superior in lowering the PCO score and the Nd:YAG laser capsulotomy rate, but not visual acuity. PMID:29095259

  18. Refractive accuracy with light-adjustable intraocular lenses.

    Science.gov (United States)

    Villegas, Eloy A; Alcon, Encarna; Rubio, Elena; Marín, José M; Artal, Pablo

    2014-07-01

    To evaluate efficacy, predictability, and stability of refractive treatments using light-adjustable intraocular lenses (IOLs). University Hospital Virgen de la Arrixaca, Murcia, Spain. Prospective nonrandomized clinical trial. Eyes with a light-adjustable IOL (LAL) were treated with spatial intensity profiles to correct refractive errors. The effective changes in refraction in the light-adjustable IOL after every treatment were estimated by subtracting those in the whole eye and the cornea, which were measured with a Hartmann-Shack sensor and a corneal topographer, respectively. The refractive changes in the whole eye and light-adjustable IOL, manifest refraction, and visual acuity were obtained after every light treatment and at the 3-, 6-, and 12-month follow-ups. The study enrolled 53 eyes (49 patients). Each tested light spatial pattern (5 spherical; 3 astigmatic) produced a different refractive change (Plight adjustments induced a maximum change in spherical power of the light-adjustable IOL of between -1.98 diopters (D) and +2.30 D and in astigmatism of up to -2.68 D with axis errors below 9 degrees. Intersubject variability (standard deviation) ranged between 0.10 D and 0.40 D. The 2 required lock-in procedures induced a small myopic shift (range +0.01 to +0.57 D) that depended on previous adjustments. Light-adjustable IOL implantation achieved accurate refractive outcomes (around emmetropia) with good uncorrected distance visual acuity, which remained stable over time. Further refinements in nomograms and in the treatment's protocol would improve the predictability of refractive and visual outcomes with these IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. Recurrent uveitis and pigment dispersion in an eye with in-the-bag acrylic foldable intraocular lens.

    Science.gov (United States)

    Thakur, Monica; Bhatia, Prashant; Chandrasekhar, Garudadri; Senthil, Sirisha

    2016-02-26

    Phacoemulsification with in-the-bag intraocular lens (IOL) implantation is the standard procedure for cataract surgery. Pigment dispersion and uveitis can result when an IOL is placed in the sulcus. We report a case of a 64-year-old woman, with pigmentary glaucoma, who developed recurrent uveitis following uneventful cataract surgery and an in-the-bag hydrophobic acrylic IOL implant. Recurrent uveitis did not subside despite use of topical steroids over 3 months. Dilated examination revealed capsulophimosis with anterior dislocation of the IOL haptic. The mechanical trauma to the iris due to the displaced haptic was implicated as the cause of recurrent uveitis, which completely resolved after capsular excision and IOL repositioning. This case illustrates a rare cause of recurrent uveitis due to IOL haptic dislocation following severe capsulophimosis. 2016 BMJ Publishing Group Ltd.

  20. Visual function after implantation of single-piece toric hydrophilic acrylic intraocular lenses with hydrophobic surface six months after cataract surgery

    Directory of Open Access Journals (Sweden)

    Alja Črnej

    2012-06-01

    Conclusion: Patients with medium to high corneal astigmatism and implanted single-piece toric hydrophilic acrylic IOLs with hydrophobic surface have very good visual function six months postoperatively.

  1. Modification of hydrophobic acrylic intraocular lens with poly(ethylene glycol) by atmospheric pressure glow discharge: A facile approach

    International Nuclear Information System (INIS)

    Lin Lin; Wang Yao; Huang Xiaodan; Xu Zhikang; Yao Ke

    2010-01-01

    To improve the anterior surface biocompatibility of hydrophobic acrylic intraocular lens (IOL) in a convenient and continuous way, poly(ethylene glycol)s (PEGs) were immobilized by atmospheric pressure glow discharge (APGD) treatment using argon as the discharge gas. The hydrophilicity and chemical changes on the IOL surface were characterized by static water contact angle and X-ray photoelectron spectroscopy to confirm the covalent binding of PEG. The morphology of the IOL surface was observed under field emission scanning electron microscopy and atomic force microscopy. The surface biocompatibility was evaluated by adhesion experiments with platelets, macrophages, and lens epithelial cells (LECs) in vitro. The results revealed that the anterior surface of the PEG-grafted IOL displayed significantly and permanently improved hydrophilicity. Cell repellency was observed, especially in the PEG-modified IOL group, which resisted the attachment of platelets, macrophages and LECs. Moreover, the spread and growth of cells were suppressed, which may be attributed to the steric stabilization force and chain mobility effect of the modified PEG. All of these results indicated that hydrophobic acrylic IOLs can be hydrophilic modified by PEG through APGD treatment in a convenient and continuous manner which will provide advantages for further industrial applications.

  2. Instrumental studies on silicone oil adsorption to the surface of intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chun Ho [Lab. of Tissue Engineering, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Joo, Choun-Ki [Department of Ophthalmology and Visual Science, Medical College of Catholic University, Seoul 137-701 (Korea, Republic of); Chun, Heung Jae, E-mail: chunhj@catholic.ac.kr [Institute of Cell and Tissue Engineering, Medical College of Catholic University, Seoul 137-701 (Korea, Republic of); Yoo, Bok Ryul [Organosilicone Chemistry Laboratory, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Noh, Dong Il; Shim, Young Bock [Research Institute of Biomedical Engineering, Korea Bone Bank Co. Ltd., Seoul 153-782 (Korea, Republic of)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer It was found that PHEMA and Acrysof IOLs possess silicone oil repellant ability. Black-Right-Pointing-Pointer The residual silicone oil was detected on the surfaces of PMMA and silicone IOLs. Black-Right-Pointing-Pointer XPS studies showed that silicone oil coverage of PMMA lenses was 12%. Black-Right-Pointing-Pointer Silicone oil covered the entire surface of the silicone IOLs. - Abstract: The purpose of this study was to examine the degree of adherence of silicone oil to various intraocular lenses (IOLs) through comparison of the physico-chemical properties of the oil and IOLs. Four kinds of IOLs comprising various biomaterials were examined: PMMA (720A Trade-Mark-Sign ), PHEMA (IOGEL 1103 Trade-Mark-Sign ), Acrysof (MA60BM Trade-Mark-Sign ), and silicone (SI30NB Trade-Mark-Sign ). Each lens was immersed in silicone oil or carboxylated silicone (CS-PDMS) oil for 72 h. For determination of the changes in chemical and elemental compositions on the surfaces of IOLs caused by the contact with silicone oil, IOLs were washed and rinsed with n-pentane to remove as much of the adsorbed silicone oil as possible, then subjected to Fourier transform infrared spectroscopic (FTIR) and X-ray photoelectron spectroscopic (XPS) analyses. The results of FTIR studies strongly indicate that washing with n-pentane completely removed the adhered silicone oil on the surfaces of PHEMA and Acrysof IOLs, whereas the residual silicone oil was detected on the surfaces of PMMA and silicone IOLs. XPS studies showed that silicone oil coverage of PMMA lenses was 12%, even after washing with n-pentane. In the case of silicone IOLs, the relative O1s peak area of carboxyl group in the residual CS-PDMS oil was found to be {approx}2.7%. Considering that 2.8% carboxyl group-substituted silicone oil was used in the present study, CS-PDMS oil covered the entire surface of the silicone IOLs.

  3. Epidemiological evaluation of YAG capsulotomy incidence for posterior capsule opacification in various intraocular lenses in Japanese eyes

    Directory of Open Access Journals (Sweden)

    Nishi Y

    2015-09-01

    Full Text Available Yutaro Nishi,1,2 Tomohiro Ikeda,1 Kayo Nishi,2 Osamu Mimura1 1Department of Ophthalmology, Hyogo College of Medicine, Hyogo, 2Nishi Eye Hospital, Osaka, Japan Background and objective: We investigated the yttrium aluminum garnet (YAG capsulotomy rates in various intraocular lenses (IOLs. Study design/patients and methods: We retrospectively analyzed 23,440 eyes implanted with either MA60BM, MA60AC, VA-60BB, CeeOnEdge, Clariflex, Technis Z9002, SI-40NB, or UV26T IOLs. We calculated the YAG capsulotomy rates at 1, 3, 5, and 10 years post lens implantation. Results: YAG capsulotomy rates at 3 years postimplantation for the eight groups of IOLs were, respectively, 3.7%, 3.9%, 23.7%, 3.4%, 4.5%, 4.7%, 10.4%, and 21.0%. YAG capsulotomy rates at 10 years postimplantation for the MA60BM and SI-40NB IOLs were, respectively, 9.1% and 15% (P<0.05. The average YAG rates for all sharp-edged and round-edged IOLs at 5 years postimplantation were, respectively, 5.2%±0.7% and 25.6%±9.0% (P<0.05. Conclusion: In all studied IOLs, posterior capsule opacification prevention seemed to be associated with the posterior optic sharp-edge design. Round-edged silicone IOLs may also retard posterior capsule opacification formation, though not as much as sharp-edged IOLs. As the follow-up period progressed, round-edged silicone IOLs showed significantly higher YAG rates than sharp-edged IOLs. Keywords: silicone, intraocular lenses, sharp optic edge, chi-square test, implantation surgery, posterior capsule opacification

  4. [Halos and multifocal intraocular lenses: origin and interpretation].

    Science.gov (United States)

    Alba-Bueno, F; Vega, F; Millán, M S

    2014-10-01

    To present the theoretical and experimental characterization of the halo in multifocal intraocular lenses (MIOL). The origin of the halo in a MIOL is the overlaying of 2 or more images. Using geometrical optics, it can be demonstrated that the diameter of each halo depends on the addition of the lens (ΔP), the base power (P(d)), and the diameter of the IOL that contributes to the «non-focused» focus. In the image plane that corresponds to the distance focus, the halo diameter (δH(d)) is given by: δH(d)=d(pn) ΔP/P(d), where d(pn) is the diameter of the IOL that contributes to the near focus. Analogously, in the near image plane the halo diameter (δH(n)) is: δH(n)=d(pd) ΔP/P(d), where d(pd) is the diameter of the IOL that contributes to the distance focus. Patients perceive halos when they see bright objects over a relatively dark background. In vitro, the halo can be characterized by analyzing the intensity profile of the image of a pinhole that is focused by each of the foci of a MIOL. A comparison has been made between the halos induced by different MIOL of the same base power (20D) in an optical bench. As predicted by theory, the larger the addition of the MIOL, the larger the halo diameter. For large pupils and with MIOL with similar aspheric designs and addition (SN6AD3 vs ZMA00), the apodized MIOL has a smaller halo diameter than a non-apodized one in distance vision, while in near vision the size is very similar, but the relative intensity is higher in the apodized MIOL. When comparing lenses with the same diffractive design, but with different spherical-aspheric base design (SN60D3 vs SN6AD3), the halo in distance vision of the spherical MIOL is larger, while in near vision the spherical IOL induces a smaller halo, but with higher intensity due to the spherical aberration of the distance focus in the near image. In the case of a trifocal-diffractive IOL (AT LISA 839MP) the most noticeable characteristic is the double-halo formation due to the 2 non

  5. Intraocular pressure measurements in relation to head position and through soft contact lenses: comparison of three portable instruments.

    Science.gov (United States)

    Klein, Ainat; Shemesh, Gabi; Loewenstein, Anat; Kurtz, Shimon

    2011-01-01

    to compare the reproducibility of three portable instruments-the Tono-Pen tonometer (Reichert Ophthalmic Instruments, Depew, NY), the Phosphene tonometer (Bausch & Lomb, Rochester, NY), and the TERT (Through Eyelid Russian Tonometer; Rjazan State Instrument Making, Rjazan, Russia)-in the measurement of intraocular pressure (IOP) with and without soft contact lenses and in different head positions. twenty-six eyes of healthy volunteers were examined by the three instruments while the subjects were sitting, recumbent, and hyperextending their heads, and with and without contact lenses. IOP measurements were compared and the effects of head position and presence of contact lenses on the resultant values were analyzed. the average difference between the recumbent and sitting positions was 3.56, 2.68, and 2.62 mm Hg for the Tono-Pen tonometer, Phosphene tonometer, and TERT, respectively. There was an increase of 5.60, 2.78, and 2.63 mm Hg in hyperextension compared to sitting for the Tono-Pen tonometer, Phosphene tonometer, and TERT, respectively. The difference in the IOP values obtained in the presence and absence of therapeutic contact lens for the three instruments in the three positions was between -1.23 and +1.47 mm Hg. IOP measurements of bedridden patients are only slightly higher than those of sitting patients except for the Tono-Pen tonometer in the hyperextension position. The presence of contact lenses does not affect IOP values obtained by the three evaluated instruments.

  6. Comparison of hydrophobic and hydrophilic intraocular lens in preventing posterior capsule opacification after cataract surgery: An updated meta-analysis.

    Science.gov (United States)

    Zhao, Yang; Yang, Ke; Li, Jiaxin; Huang, Yang; Zhu, Siquan

    2017-11-01

    Posterior capsular opacification (PCO) is a common long-term complication of cataract surgery. Intraocular lens design and material have been implicated in influencing the development of PCO. This study evaluated the association of hydrophobic and hydrophilic intraocular lenses on preventing PCO. Medline, Cochrane, EMBASE, and Google Scholar databases were searched until August 3, 2016, using the following search terms: cataract, posterior capsule opacification, and intraocular lens. Eligible studies included randomized controlled trials (RCTs), retrospective, and cohort studies. Eleven studies were included in the study with a total of 889 eyes/patients. The overall analysis revealed that hydrophobic intraocular lenses were associated with lower Nd:YAG laser capsulotomy rates than hydrophilic lenses [odds ratio (OR) = 0.38, 95% confidence interval (95% CI) = 0.16-0.91, P = .029]. Hydrophobic intraocular lenses were also associated with lower subjective PCO score (diff. in means: -1.32, 95% CI = -2.39 to -0.25, P = .015) and estimated PCO score (diff. in means: -2.23; 95% CI, -3.80 to -0.68, P = .005) as compared with hydrophilic lenses. Objective PCO score was similar between lens types. (diff. in means: -0.075; 95% CI, -0.18 to 0.035; P = .182). Pooled analysis found that visual acuity was similar between hydrophobic and hydrophilic intraocular lenses (diff. in means: -0.016; 95% CI, -0.041 to 0.009, P = .208). In general, PCO scores and the rate of Nd:YAG laser capsulotomy were influenced by intraocular lens biomaterial. Lens made of hydrophobic biomaterial were overall superior in lowering the PCO score and the Nd:YAG laser capsulotomy rate, but not visual acuity.

  7. Controlled release of moxifloxacin from intraocular lenses modified by Ar plasma-assisted grafting with AMPS or SBMA: An in vitro study.

    Science.gov (United States)

    Pimenta, A F R; Vieira, A P; Colaço, R; Saramago, B; Gil, M H; Coimbra, P; Alves, P; Bozukova, D; Correia, T R; Correia, I J; Guiomar, A J; Serro, A P

    2017-08-01

    Intraocular lenses (IOLs) present an alternative for extended, local drug delivery in the prevention of post-operative acute endophthalmitis. In the present work, we modified the surface of a hydrophilic acrylic material, used for manufacturing of IOLs, through plasma-assisted grafting copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), with the aim of achieving a controlled and effective drug release. The material was loaded with moxifloxacin (MFX), a commonly used antibiotic for endophthalmitis prevention. The characterization of the modified material showed that relevant properties, like swelling capacity, wettability, refractive index and transmittance, were not affected by the surface modification. Concerning the drug release profiles, the most promising result was obtained when AMPS grafting was done in the presence of MFX. This modification led to a higher amount of drug being released for a longer period of time, which is a requirement for the prevention of endophthalmitis. The material was found to be non-cytotoxic for rabbit corneal endothelial cells. In a second step, prototype IOLs were modified with AMPS and loaded with MFX as previously and, after sterilization and storage (30days), they were tested under dynamic conditions, in a microfluidic cell with volume and renovation rate similar to the eye aqueous humour. MFX solutions collected in this assay were tested against Staphylococcus aureus and Staphylococcus epidermidis and the released antibiotic proved to be effective against both bacteria until the 12th day of release. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Safety and effectiveness of a glistening-free single-piece hydrophobic acrylic intraocular lens (enVista

    Directory of Open Access Journals (Sweden)

    Packer M

    2013-09-01

    Full Text Available Mark Packer,1 Luther Fry,2 Kevin T Lavery,3 Robert Lehmann,4 James McDonald,5 Louis Nichamin,6 Brian Bearie,7,† Jon Hayashida,8 Griffith E Altmann,8 Omid Khodai8 1Department of Ophthalmology, Oregon Health and Science University, Eugene, OR, USA; 2University of Kansas Medical Center, Kansas City, KS, USA; 3Wayne State University, Detroit, MI, USA; 4Baylor College of Medicine, Houston, TX, USA; 5University of Arkansas for Medical Sciences, Little Rock, AR, USA; 6Laurel Eye Clinic, Brookville, PA, USA; 7Grand Rapids Eye Institute, Grand Rapids, MI, USA; 8Bausch & Lomb, Aliso Viejo, CA, USA †Brian Bearie passed away on March 9, 2011 Purpose: To evaluate the safety and effectiveness of a single-piece hydrophobic acrylic intraocular lens (IOL; enVista model MX60; Bausch & Lomb, Rochester, NY, USA when used to correct aphakia following cataract extraction in adults. Methods: This was a prospective case series (NCT01230060 conducted in private practices in the US. Eligible subjects were adult patients with age-related cataract amenable to treatment with standard phacoemulsification/extracapsular cataract extraction. With follow-up of 6 months, primary safety and effectiveness end points included the rates of US Food and Drug Administration (FDA-defined cumulative and persistent adverse events and the percentage of subjects who achieved best-corrected visual acuity (BCVA of 20/40 or better at final visit. To evaluate rotational stability, subjects were randomized (1:1:1:1 to have the lens implanted in one of four axis positions in 45° increments. Results: A total of 122 subjects were enrolled. The rate of cumulative and persistent adverse events did not significantly exceed historical controls, as per FDA draft guidance. At the final postoperative visit, all subjects (100% achieved a BCVA of 20/40 compared with the FDA historical control of 96.7%. Rotation of the IOL between the two final follow-up visits was ≤5° for 100% of eyes, and refractive

  9. Plasma surface modification of rigid contact lenses decreases bacterial adhesion.

    Science.gov (United States)

    Wang, Yingming; Qian, Xuefeng; Zhang, Xiaofeng; Xia, Wei; Zhong, Lei; Sun, Zhengtai; Xia, Jing

    2013-11-01

    Contact lens safety is an important topic in clinical studies. Corneal infections usually occur because of the use of bacteria-carrying contact lenses. The current study investigated the impact of plasma surface modification on bacterial adherence to rigid contact lenses made of fluorosilicone acrylate materials. Boston XO and XO2 contact lenses were modified using plasma technology (XO-P and XO2-P groups). Untreated lenses were used as controls. Plasma-treated and control lenses were incubated in solutions containing Staphylococcus aureus or Pseudomonas aeruginosa. MTT colorimetry, colony-forming unit counting method, and scanning electron microscopy were used to measure bacterial adhesion. MTT colorimetry measurements showed that the optical density (OD) values of XO-P and XO2-P were significantly lower than those of XO and XO2, respectively, after incubation with S. aureus (P lenses and to the XO2-P versus XO2 lenses incubated with S. aureus (P lenses incubated with P. aeruginosa (P lenses. Plasma surface modification can significantly decrease bacterial adhesion to fluorosilicone acrylate contact lenses. This study provides important evidence of a unique benefit of plasma technology in contact lens surface modification.

  10. A comparison of visual outcomes in three different types of monofocal intraocular lenses.

    Science.gov (United States)

    Shetty, Vijay; Haldipurkar, Suhas S; Gore, Rujuta; Dhamankar, Rita; Paik, Anirban; Setia, Maninder Singh

    2015-01-01

    To compare the visual outcomes (distance and near) in patients opting for three different types of monofocal intraocular lens (IOL) (Matrix Aurium, AcrySof single piece, and AcrySof IQ lens). The present study is a cross-sectional analysis of secondary clinical data collected from 153 eyes (52 eyes in Matrix Aurium, 48 in AcrySof single piece, and 53 in AcrySof IQ group) undergoing cataract surgery (2011-2012). We compared near vision, distance vision, distance corrected near vision in these three types of lenses on day 15 (±3) post-surgery. About 69% of the eyes in the Matrix Aurium group had good uncorrected distance vision post-surgery; the proportion was 48% and 57% in the AcrySof single piece and AcrySof IQ group (P=0.09). The proportion of eyes with good distance corrected near vision were 38%, 33%, and 15% in the Matrix Aurium, AcrySof single piece, and AcrySof IQ groups respectively (P=0.02). Similarly, The proportion with good "both near and distance vision" were 38%, 33%, and 15% in the Matrix Aurium, AcrySof single piece, and AcrySof IQ groups respectively (P=0.02). It was only the Matrix Aurium group which had significantly better both "distance and near vision" compared with the AcrySof IQ group (odds ratio: 5.87, 95% confidence intervals: 1.68 to 20.56). Matrix Aurium monofocal lenses may be a good option for those patients who desire to have a good near as well as distance vision post-surgery.

  11. Bacterial contamination of intraocular lens surgery.

    OpenAIRE

    Vafidis, G C; Marsh, R J; Stacey, A R

    1984-01-01

    One hundred sterile intraocular lenses were placed on the external eye of 50 patients during cataract surgery. Half of the specimens were cultured for bacteria, the other half were examined under the light microscope after fixing and staining. A bacterial contamination rate of 26% was recorded. This is significantly higher than that found in conjunctival swabs (6%) or irrigation specimens (8%) taken at the same time, and higher than that recorded in a group of control lenses (15.2%) exposed t...

  12. Piggyback intraocular lens implantation to correct pseudophakic refractive error after segmental multifocal intraocular lens implantation.

    Science.gov (United States)

    Venter, Jan A; Oberholster, Andre; Schallhorn, Steven C; Pelouskova, Martina

    2014-04-01

    To evaluate refractive and visual outcomes of secondary piggyback intraocular lens implantation in patients diagnosed as having residual ametropia following segmental multifocal lens implantation. Data of 80 pseudophakic eyes with ametropia that underwent Sulcoflex aspheric 653L intraocular lens implantation (Rayner Intraocular Lenses Ltd., East Sussex, United Kingdom) to correct residual refractive error were analyzed. All eyes previously had in-the-bag zonal refractive multifocal intraocular lens implantation (Lentis Mplus MF30, models LS-312 and LS-313; Oculentis GmbH, Berlin, Germany) and required residual refractive error correction. Outcome measurements included uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, distance-corrected near visual acuity, manifest refraction, and complications. One-year data are presented in this study. The mean spherical equivalent ranged from -1.75 to +3.25 diopters (D) preoperatively (mean: +0.58 ± 1.15 D) and reduced to -1.25 to +0.50 D (mean: -0.14 ± 0.28 D; P < .01). Postoperatively, 93.8% of eyes were within ±0.50 D and 98.8% were within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity improved significantly from 0.28 ± 0.16 to 0.01 ± 0.10 logMAR and 78.8% of eyes achieved 6/6 (Snellen 20/20) or better postoperatively. The mean uncorrected near visual acuity changed from 0.43 ± 0.28 to 0.19 ± 0.15 logMAR. There was no significant change in corrected distance visual acuity or distance-corrected near visual acuity. No serious intraoperative or postoperative complications requiring secondary intraocular lens removal occurred. Sulcoflex lenses proved to be a predictable and safe option for correcting residual refractive error in patients diagnosed as having pseudophakia. Copyright 2014, SLACK Incorporated.

  13. The effect of hydrogel and silicone hydrogel contact lenses on the measurement of intraocular pressure with rebound tonometry.

    Science.gov (United States)

    Zeri, Fabrizio; Calcatelli, Paolo; Donini, Bernardo; Lupelli, Luigi; Zarrilli, Luciana; Swann, Peter G

    2011-12-01

    To assess the accuracy of intraocular pressure (IOP) measurements using rebound tonometry over disposable hydrogel (etafilcon A) and silicone hydrogel (senofilcon A) contact lenses (CLs) of different powers. The experimental group comprised 36 subjects (19 male, 17 female). IOP measurements were undertaken on the subject's right eyes in random order using a rebound tonometer (ICare). The CLs had powers of +2.00D, -2.00D and -6.00D. Six measurements were taken over each contact lens and also before and after the CLs had been worn. A good correlation was found between IOP measurements with and without CLs (all r≥0.80; pContact Lens Association. Published by Elsevier Ltd. All rights reserved.

  14. [IOP measurement through frequent-replacement soft contact lenses].

    Science.gov (United States)

    Touboul, J

    2008-07-01

    Intraocular pressure (IOP) can be measured through soft contact lenses with an air-puff tonometer. These measurements seemed accurate for low-power negative lenses. For positive soft contact lenses, IOP is overestimated. The measurement of IOP through a soft contact lens is acceptable in clinical practice only for glaucoma screening. In glaucomatous patients or patients with ocular hypertension, IOP measurements should be performed without a contact lens. The main technique for IOP measurement remains Goldmann applanation tonometry.

  15. Aberration-free intraocular lenses - What does this really mean?

    Science.gov (United States)

    Langenbucher, Achim; Schröder, Simon; Cayless, Alan; Eppig, Timo

    2017-09-01

    So-called aberration-free intraocular lenses (IOLs) are well established in modern cataract surgery. Usually, they are designed to perfectly refract a collimated light beam onto the focal point. We show how much aberration can be expected with such an IOL in a convergent light beam such as that found anterior to the human cornea. Additionally, the aberration in a collimated beam is estimated for an IOL that has no aberrations in the convergent beam. The convergent beam is modelled as the pencil of rays corresponding to the spherical wavefront resulting from a typical corneal power of 43m -1 . The IOLs are modelled as infinitely thin phase plates with 20m -1 optical power placed 5mm behind the cornea. Their aberrations are reported in terms of optical path length difference and longitudinal spherical aberration (LSA) of the marginal rays, as well as nominal spherical aberration (SA) calculated based on a Zernike representation of the wavefront-error at the corneal plane within a 6mm aperture. The IOL designed to have no aberrations in a collimated light beam has an optical path length difference of -1.8μm, and LSA of 0.15m -1 in the convergent beam of a typical eye. The corresponding nominal SA is 0.065μm. The IOL designed to have no aberrations in a convergent light beam has an optical path length difference of 1.8μm, and LSA of -0.15m -1 in the collimated beam. An IOL designed to have no aberrations in a collimated light beam will increase the SA of a patient's eye after implantation. Copyright © 2017. Published by Elsevier GmbH.

  16. Photochemical generation of antimicrobial Ag-nanoparticles in intraocular lenses

    Science.gov (United States)

    Badur, Thorben; Kim, Hee-Cheol; Hampp, Norbert

    2017-02-01

    The antimicrobial properties of silver (Ag) nanoparticles (NP) have been investigated in depth during the last decades.[1] For cataract treatment minimal invasive surgery has become state-of-the-art. The physicians are still fighting against postoperative inflammations, such as endophthalmitis.[2] We present a novel approach to reduce these postoperative complications by equipping the hydrophilic intraocular lenses (IOL) with a Ag NP depot. As the Ag NP are completely entrapped inside the polymeric IOL no direct contact of the nanoparticles with epithelial cells may occur. Using 1-hydroxybenzotriazole (HOBt) or 7-hydroxycumarine (7HOCum) as photo reduction mediators (PRM) the formation of the Ag NP is accomplished in situ. PRM and Ag nitrate are diffused into the ready made IOL. By means of two-photon-absorption (TPA) photochemistry at λTPA = 532 nm the Ag NP generation is precisely controlled to occur inside the IOL only. At no point NP are directly exposed to the surface.[3] Interesting dependencies between the used PRM and the resulting particle size distribution or the effectiveness of the silver ion reduction inside the polymer matrix are reported. The Ag NP were prepared in the outer area of the IOL not to affect the optical properties of the ophthalmic implant. The amount of Ag ions released was determined and found to be sufficient to effectively reduce the counts of airborne germs. Besides HOBt and 7HOCum we also investigated the photo reductive properties of several other organic reagents, such as benzophenone (BP) and 4-hydroxybenzophenone (4HOBP) for the ability to produce even three-dimensional nanoparticle structures inside a polymer matrix.

  17. Computerized calculation scheme for toric intraocular lenses.

    Science.gov (United States)

    Langenbucher, Achim; Seitz, Berthold

    2004-06-01

    While a number of intraocular lens (IOL) power prediction formulae are well established for determination of spherical lenses, no common strategy has been published for the computation of toric IOLs. The purpose of this study is to describe a paraxial computing scheme for tracing an axial pencil of rays through the 'optical system eye' containing astigmatic refractive surfaces with their axes at random. The capabilities of this computing scheme are demonstrated with clinical examples. Based on a schematic model eye with spherocylindric surfaces, we use two alternative notations for description of vergences or prescriptions: (1) standard notation (refraction in both cardinal meridians and axis), and (2) component notation (spherical equivalent and cylindric component in 0 degrees and 45 degrees. Refractive surfaces are added to the vergence in component notation, whereas the transformation of the vergence through media is performed in the standard notation for both cardinal meridians. For calculation of the toric lens implant, a pencil of rays is traced through the spectacle and the cornea to the estimated lens position as well as backwards from the retina to the estimated lens position. For calculation of residual spectacle refraction, a pencil of rays is traced backwards from the retina through the toric lens implant and the cornea to the spectacle plane. In example 1 we calculate a 'thin toric lens' for compensation of a corneal astigmatism to achieve a spherical target refraction. In example 2 we compute a 'thick toric lens', which has to compensate for an oblique corneal astigmatism and rotate the spectacle cylinder to the against the rule position to enhance near vision. In example 3 we estimate the residual refraction at the corneal plane after implantation of a thick toric lens, when the cylinder of the lens implant is compensating the corneal cylinder in part and the axis of implantation is not fully aligned with the axis of the corneal astigmatism. This

  18. Gas chromatographic determination with electron capture detection of residual ethylene oxide in intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, H.; Nakamura, A.; Tsuji, K.

    1988-01-01

    A sensitive method is described to determine trace quantities of ethylene oxide (EO) in EO-sterilized intraocular lenses (IOLs). An IOL is dipped in ethanol containing 0.25 ppm propylene oxide (PO) in a 4 mL vial, 2 drops of freshly distilled hydrobromic acid is added through a septum, and the mixture is warmed at 50/sup 0/C for 24 h. It is then neutralized by vigorous shaking with sodium bicarbonate, dehydrated with anhydrous sodium sulfate, and filtered. The filtrate is injected into a gas chromatograph with electron-capture detection, and the peak height ratio of ethylene bromohydrin/propylene bromohydrin is measured. EO residue is calculated from the calibration curve obtained through a similar procedure with the standard EO/PO solutions. The limit of determination is 0.04 ..mu..g/lens (ca 2.0 ppm). When EO residue levels were determined for IOLs sampled at 3 different aeration periods after stabilization, the authors found that 9 days of aeration was necessary to meet the US Food and Drug Administration proposed limit for EO residue in IOLs.

  19. Bilateral spontaneous dislocation of posterior chamber intraocular lens in a patient with gyrate atrophy

    Directory of Open Access Journals (Sweden)

    Michael Kinori

    2012-01-01

    Full Text Available We report a patient with gyrate atrophy, a rare metabolic disease, who had bilateral late spontaneous posterior dislocation of in-the-bag posterior chamber intraocular lens (PCIOL. He underwent pars plana vitrectomy, PCIOL retrieval and anterior chamber intraocular lens implantation in both eyes. This report may imply that patients with gyrate atrophy are at risk for spontaneous dislocation of intraocular lenses.

  20. Phakic intraocular lenses for the treatment of refractive errors: an evidence-based analysis.

    Science.gov (United States)

    2009-01-01

    The objective of this analysis is to review the effectiveness, safety, and cost-effectiveness of phakic intraocular lenses (pIOLs) for the treatment of myopia, hyperopia, and astigmatism. CONDITION AND TARGET POPULATION REFRACTIVE ERRORS: Refractive errors occur when the eye cannot focus light properly. In myopia (near- or short-sightedness), distant objects appear blurry because the axis of the eye is too long or the cornea is too steep, so light becomes focused in front of the retina. Hyperopia (far sightedness) occurs when light is focused behind the retina causing nearby objects to appear blurry. In astigmatism, blurred or distorted vision occurs when light is focused at two points rather than one due to an irregularly shaped cornea or lens. Refractive errors are common worldwide, but high refractive errors are less common. In the United States, the prevalence of high myopia (≤ -5 D) in people aged 20 to 39, 40 to 59, and 60 years and older is 7.4% (95% confidence interval [CI], 6.5% - 8.3%), 7.8% (95% CI, 6.4% - 8.6%), and 3.1% (95% CI, 2.2% - 3.9%), respectively. The prevalence of high hyperopia (≥ 3 D) is 1.0% (95% CI, .6% - 1.4%), 2.4% (95% CI, 1.7% - 3.0%), and 10.0% (95% CI, 9.1% - 10.9%) for the same age groupings. Finally, the prevalence of astigmatism (≥ 1 D cylinder) is 23.1% (95% CI, 21.6% - 24.5%), 27.6% (95% CI, 25.8% - 29.3%) and 50.1% (48.2% - 52.0%). LOW VISION: According to the Ontario Schedule of Benefits, low visual acuity is defined by a best spectacle corrected visual acuity (BSCVA) of 20/50 (6/15) or less in the better eye and not amenable to further medical and/or surgical treatment. Similarly, the Ontario Assistive Devices Program defines low vision as BSCVA in the better eye in the range of 20/70 or less that cannot be corrected medically, surgically, or with ordinary eyeglasses or contact lenses. Estimates of the prevalence of low vision vary. Using the criteria of BSCVA ranging from 20/70 to 20/160, one study estimated that 35

  1. Comparação da análise da frente de onda e da sensibilidade ao contraste em olhos pseudofácicos com implante de lentes intra-oculares esférica e asférica Wavefront analysis and contrast sensitivity comparison between spheric and aspheric intraocular lenses

    Directory of Open Access Journals (Sweden)

    Wilson Takashi Hida

    2008-06-01

    Full Text Available OBJETIVO: Comparar a análise da frente de onda e a sensibilidade de contraste pós-operatórias em pacientes submetidos à facoemulsificação com implante de lentes intra-oculares esféricas num olho e asféricas no olho contralateral. MÉTODOS: Este estudo prospectivo comparativo, randomizado, duplo-cego, incluiu 32 olhos de 16 pacientes. Uma avaliação oftalmológica completa foi realizada durante as visitas antes e depois da cirurgia (no primeiro, terceiro, sétimo, e nonagésimo dias pós-cirúrgicos, que incluiu acuidade visual, teste de sensibilidade ao contraste, aberrometria. Todos exames (menos aberrometr=ia foram feitos monocularmente com pupilas não dilatadas. Os pacientes foram submetidos a facectomia ultra-sônica convencional com implante de uma lente asférica SN60WF num olho e esférica SN60ATno outro. RESULTADOS: A acuidade visual média com a melhor correção foi -0,146 LogMAR no grupo da lente intra-ocular esférica, e -0.165 logMAR no grupo da lente intra-ocular asférica sob condições fotópicas, -0,003 LogMAR sob condições mesópicas. A sensibilidade ao contraste foi semelhante em ambos os grupos tanto em condições fotópicas e mesópicas. Em relação às aberrações ópticas ocorreu uma diferença significativa nas aberrações totais (1,09 ± 0,56 no grupo asférico e 1,52 ± 1,19 no grupo esférico e no componente esférico das aberrações de alta ordem(0,422 ± 0,202 no grupo asférico e 0,124 ± 0,087 no grupo esférico. CONCLUSÃO: As duas lentes intra-oculares promoveram uma excelente visão em situações de alto contraste, e os olhos implantados com a lente asférica tiveram menos aberrações totais e esféricas que aqueles implantados com a lente esférica.PURPOSE: Compare the wavefront and contrast sensitivity of bilateral pseudophakic patients with aspheric in one eye and spheric intraocular lenses in the other. METHODS: This prospective, comparative, randomized study, double masked, included 32

  2. Subluxation of suture-fixated posterior chamber intraocular lenses a clinicopathologic study.

    Science.gov (United States)

    Parekh, Parag; Green, W Richard; Stark, Walter J; Akpek, Esen Karamursel

    2007-02-01

    To report the occurrence of subluxation of suture-fixated posterior chamber (PC) intraocular lenses (IOL) and elucidate the mechanisms involved. Prospective clinicopathologic study. A single 10-0 Prolene suture explanted from a patient who experienced subluxation of his PC-IOL, 11.5 years after placement. Furthermore, multiple 10-0 Prolene sutures and PC-IOLs used for iris fixation were studied as controls. Scanning electron microscopy (SEM) was used to analyze the surface of the explanted suture. In addition, randomly selected 10-0 Prolene sutures cut with Vannas scissors and cut with the positioning holes of a randomly selected PC-IOL identical to that implanted in the patient's eye were examined as controls. Finally, the positioning holes of several randomly selected, iris-fixated PC-IOLs were studied using SEM with particular attention to surface quality and edge finish. Presence of any signs of suture degradation, the character of the cut edge of the suture, as well as the characteristics of the positioning holes of the PC-IOLs. Scanning electron microscopy of the explanted suture revealed sharply cut edges, without significant degradation of the suture, and no intact loop. Scanning electron microscopy of the control suture cut with a PC-IOL demonstrated a similarly cut edge. The positioning holes of the examined PC-IOLs had a sharp edge, and some also had an imperfect finish. We conclude that the surface properties of the positioning holes lead to cutting of the suture, and subsequent subluxation of the PC-IOL.

  3. The influence of lens power and center thickness on the intraocular pressure measured through soft lenses: a comparison of two noncontact tonometers.

    Science.gov (United States)

    Ogbuehi, Kelechi C

    2012-06-01

    To quantify the influence of soft contact lens power and thickness on the intraocular pressure (IOP). Thirty-nine young, healthy adult volunteers completed this study. One eye of each subject was randomly assigned either a +6D or a -6D high water content daily disposable lens. The other eye was fitted with the second lens. Triplicate measurements of IOP were taken before, during, and after contact lens wear. Each time, IOP was assessed in a randomized order with two noncontact tonometers. The lenses were swapped between eyes during a second session of measurements, one week later. In the first session with the +6D lenses, the average IOPs (±SDs) before, with the lenses fitted, and after the lenses were removed, were: 14.3 ± 2.9 mmHg, 17.0 ± 3.3 mmHg and 13.9 ± 3.1 mmHg, respectively, for the CT80 and 13.6 ± 3.1 mmHg, 17.1 ± 4.5 mmHg and 13.3 ± 2.9 mmHg, respectively, for the PT100. The corresponding values for the first session with the -6D lenses were: 14.3 ± 3.1 mmHg, 13.1 ± 3.1 mmHg and 14.1 ± 3.3 mmHg, respectively, for the CT80 and 13.6 ± 3.2 mmHg, 13.0 ± 3.0 mmHg and 13.6 ± 3.2 mmHg, respectively, for the PT100. IOP significantly (Psoft contact lens-induced changes were consistent between sessions but varied between tonometers. The measurement of IOP through soft contact lenses resulted in consistent, statistically significant differences in IOP, which were not uniform across tonometers and which did not appear to be solely related to the central thickness of the soft contact lenses. Copyright © 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  4. Intraocular pressure readings obtained through soft contact lenses using four types of tonometer

    Directory of Open Access Journals (Sweden)

    Takenaka J

    2015-10-01

    Full Text Available Joji Takenaka,1 Eriko Kunihara,1 Ulfah Rimayanti,2 Junko Tanaka,3 Makoto Kaneko,4 Yoshiaki Kiuchi1 1Department of Ophthalmology and Visual Science, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan; 2Faculty of Medicine and Health Sciences, UIN Alauddin Makassar, South Sulawesi, Indonesia; 3Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan; 4Graduate School of Engineering, Osaka University, Osaka, Japan Purpose: To compare the reliability and accuracy of intraocular pressure (IOP measured while wearing soft contact lenses (SCLs using a non-contact tonometer (NCT, Goldmann applanation tonometer (GAT, iCare rebound tonometer (RBT and the Tono-Pen XL.Methods: Twenty-six healthy subjects were examined. The IOP was measured using NCT, GAT, RBT, and the Tono-Pen XL, while the subjects wore SCLs -5.00 D, -0.50 D and +5.00 D. Bland–Altman plots and a regression analysis were used to compare the IOPs obtained with those instruments and the IOPs of the naked eyes measured using GAT (the standard IOPs in this study.Results: The IOPs obtained by the Tono-Pen XL while the subjects were wearing -5.00 D, -0.50 D, and +5.00 D SCLs were significantly higher than those of the naked eyes obtained using GAT. RBT showed that the IOPs were similar to the GAT standard IOPs under all conditions. The IOPs measured with NCT and GAT while the subjects were wearing -5.00 D and -0.50 D SCLs were similar to the GAT standard IOPs. The IOPs obtained with RBT and NCT while the subjects were wearing -5.00 D and -0.50 D SCLs exhibited a good correlation with the standard IOPs.Conclusion: The NCT and RBT are best when measuring IOP through hydrogel SCLs. Keywords: soft contact lens, intraocular pressure, rebound tonometer, non-contact tonometer

  5. Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children.

    Directory of Open Access Journals (Sweden)

    Martina Brandner

    Full Text Available To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population.Retrospective study.Ten consecutive pediatric patients (15 eyes underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed.Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident.Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate.

  6. Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children

    Science.gov (United States)

    Brandner, Martina; Thaler-Saliba, Sarah; Plainer, Sophie; Vidic, Bertram; El-Shabrawi, Yosuf; Ardjomand, Navid

    2015-01-01

    Purpose To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population. Design Retrospective study. Patients and Methods Ten consecutive pediatric patients (15 eyes) underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed. Results Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident. Conclusion Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate. PMID:26110864

  7. Change in corneal aberrations after cataract surgery with 2 types of aspherical intraocular lenses.

    Science.gov (United States)

    Marcos, Susana; Rosales, Patricia; Llorente, Lourdes; Jiménez-Alfaro, Ignacio

    2007-02-01

    To study the effect of cataract surgery through 3.2 mm superior incisions on corneal aberrations with 2 types of monofocal intraocular lenses (IOLs) with an aspherical design. Instituto de Optica, Consejo Superior de Investigaciones Científicas, and Fundación Jiménez Díaz, Madrid, Spain. Corneal topography of 43 eyes was obtained before and after small corneal incision cataract surgery. Twenty-two eyes had implantation of a Tecnis Z9000 silicone IOL (Advanced Medical Optics) and 21 had implantation of an AcrySof IQ SN60WF acrylic IOL (Alcon Research Labs) using the recommended injector for each IOL type. The intended incision size (3.2 mm) was similar in the 2 groups. Corneal aberrations were estimated using custom-developed algorithms (based on ray tracing) for 10.0 mm and 5.0 mm pupils. Comparisons between preoperative and postoperative measurements and across the groups were made for individual Zernike terms and root-mean-square (RMS) wavefront error. The RMS (excluding tilt and defocus) did not change in the AcrySof IQ group and increased significantly in the Tecnis group with the 10.0 mm and 5.0 mm pupil diameters. Spherical aberration and coma-like terms did not change significantly; however, vertical astigmatism, vertical trefoil, and vertical tetrafoil changed significantly with surgery with the 10.0 mm and 5.0 mm pupil diameters (Porder aberrations consistently showed a superior lobe, resulting from a combination of positive vertical trefoil (Z(3)(-3)) and negative tetrafoil (Z(4)(4)). The mean vertical astigmatism increased by 2.47 microm +/- 1.49 (SD) and 1.74 +/- 1.44 microm, vertical trefoil increased by 1.81 +/- 1.19 microm and 1.20 +/- 1.34 microm, and tetrafoil increased by -1.10 +/- 0.78 microm and -0.89 +/- 0.68 microm in the Tecnis group and AcrySof IQ group, respectively. There were no significant differences between the corneal aberrations in the 2 postoperative groups, although there was a tendency toward more terms or orders changing

  8. Biomicroscopia ultra-sônica na avaliação da posição das lentes intra-oculares em uma técnica de fixação escleral Ultrasound biomicroscopy in the assessment of the intraocular lenses positioning in a transscleral fixation technique

    Directory of Open Access Journals (Sweden)

    Raul de Camargo Vianna Filho

    2000-10-01

    Full Text Available Objetivo: Avaliar pela biomicrospia ultra-sônica (UBM o posicionamento, em relação ao sulco ciliar, das alças de lentes intra-oculares (LIO, em uma técnica de fixação escleral, avaliando-se também se dois pontos de fixação são suficientes para que não haja inclinação da parte óptica. Métodos: Dezesseis olhos afácicos foram submetidos a implante LIO por uma mesma técnica de fixação escleral, realizados por um mesmo cirurgião. Um mês após a cirurgia, o posicionamento das alças das LIO foram avaliados pelo UBM, assim como distâncias entre as LIO e córnea. Os resultados foram submetidos a testes estatísticos. Resultados: Das 32 alças fixadas à esclera, oito estavam localizadas no sulco ciliar e 24 fora deste. Não houve diferença estatística nas distâncias entre LIO e córnea para alças posicionadas no sulco ciliar quando comparadas àquelas localizadas fora do sulco. Isto sugere que, além da distância ao limbo que se transfixa a esclera, outros fatores devem estar associados ao posicionamento da alça no sulco ciliar. As medidas LIO -- córnea realizadas na periferia das LIO às 3, 6, 9, e 12 horas foram semelhantes, mostrando que dois pontos de fixação são suficientes para que a LIO não fique inclinada. Conclusões: Outros fatores (por exemplo o ângulo de abertura do corpo ciliar, além da distância ao limbo na qual se transfixa a esclera, são importantes para o posicionamento das alças no sulco ciliar. Dois pontos de fixação são suficientes para que a LIO não apresente inclinação dentro do olho.Purpose: To assess, through ultrasound biomicroscopy (UBM, the positioning of the intraocular lenses (IOL haptics as related to the ciliary sulcus by using a scleral fixation technique; and to evaluate, as well, if two fixation points are sufficient to avoid tilting of the lenses. Methods: Sixteen aphakic eyes underwent an IOL implan-tation by means of the same scleral fixation technique, performed by the

  9. Accuracy of intraocular pressure measurements in dogs using two different tonometers and plano therapeutic soft contact lenses.

    Science.gov (United States)

    Ahn, Jeong-Taek; Jeong, Man-Bok; Park, Young-Woo; Kim, Se-Eun; Ahn, Jae-Sang; Lee, Yes-Ran; Lee, Eui-Ri; Seo, Kangmoon

    2012-03-01

    To compare and evaluate the accuracy of intraocular pressure (IOP) measured through a therapeutic contact lens, using applanation (TonoPen XL(®)) and rebound (TonoVet(®)) tonometers in enucleated dog eyes. A total of 30 enucleated eyes from 15 beagle dogs. To measure accurate IOP, the anterior chamber of each enucleated eye was cannulated with two 26-gauge needles and two polyethylene tubes were connected vertically to an adjustable reservoir bag of normal saline and a pressure transducer. IOP was measured by the TonoPen XL(®) followed by the TonoVet(®) without a contact lens. After a contact lens was applied to the cornea, IOP was re-measured in the same order. Three consecutive IOP measurements were performed using both tonometers. Without the contact lens, the IOP values obtained by both tonometers correlated well according to the regression analysis (TonoVet(®): γ(2) = 0.98, TonoPen XL(®): γ(2) = 0.97, P contact lens was applied to the cornea. Bland-Altman analysis was used to determine the lower and upper limits of agreement (TonoVet(®): -29.7 and +21.1 mmHg, TonoPen XL(®): -3.9 and +3.6 mmHg) between the two devices. This study suggests that the TonoPen XL(®) is a useful tonometer for dogs wearing therapeutic contact lenses, and importantly, contact lenses would not need to be removed prior to IOP measurement. © 2012 American College of Veterinary Ophthalmologists.

  10. Small-incision 4-point scleral suture fixation of a foldable hydrophilic acrylic intraocular lens in the absence of capsule support.

    Science.gov (United States)

    Terveen, Daniel C; Fram, Nicole R; Ayres, Brandon; Berdahl, John P

    2016-02-01

    To determine the visual outcomes and complications of a new small-incision technique for 4-point fixation of a hydrophilic acrylic posterior chamber intraocular lens (IOL) in the absence of capsule support. Three North American tertiary referral centers and a private practice. Retrospective case series. Secondary IOL placement was performed from 2011 to 2014. Indications for surgery, clinical results, and complications were analyzed. Primary outcomes included postoperative corrected distance visual acuity (CDVA) and surgical complications. Charts of 35 patients (37 eyes) were reviewed. The mean age at surgery was 56 years, and the mean follow-up was 6 months (range 3 to 24 months). Clinical indications included a dislocated IOL (30%), ocular trauma (19%), crystalline lens subluxation (19%), uveitis-glaucoma-hyphema syndrome (5%), post-complicated cataract (8%), congenital cataract (8%), and decompensated cornea (3%). The mean CDVA improved from 20/80 preoperatively to 20/40 postoperatively (P IOL dislocation (3%). Small-incision 4-point scleral fixation of the Akreos AO60 hydrophilic acrylic IOL in the absence of capsule support appears to be a safe and effective technique for secondary IOL placement. Drs. Berdahl and Ayres are consultants to Bausch & Lomb, Inc. Drs. Ayres and Fram have received speaker fees from Bausch & Lomb. Dr. Terveen does not have a financial or proprietary interest in any material or methods mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. Late dislocation of in-the-bag intraocular lenses in uveitic eyes: An analysis of management and complications

    Directory of Open Access Journals (Sweden)

    Sudha K Ganesh

    2017-01-01

    Full Text Available Aim: An analysis of late in-the-bag dislocation of intraocular lenses (IOL, in uveitic eyes. Setting: Referral uveitis clinic. Design: Retrospective case series. Materials and Methods: All case records of eyes with chronic uveitis that had phacoemulsification with IOL implantation, at a referral uveitis clinic between February 1997 and January 2015 were retrieved and analyzed. Only those eyes with no documented intraoperative complication and no predisposing risks to IOL dislocation, such as pseudoexfoliation, high myopia, trauma, and prior VR surgery were included in this study. Results: A total of 581 eyes with chronic uveitis underwent phacoemulsification with IOL implantation under steroid cover from February 1997 to December 2015. Out of these 581 eyes, 10 patients (11 eyes had experienced late in-the-bag IOL dislocation (1.89%. All 11 eyes had chronic intermediate uveitis. The mean duration from the time of cataract surgery to IOL dislocation was 11.24 years. 5 out of 11 eyes had pars plana vitrectomy (PPV with IOL removal with 4-point sutured scleral fixated IOL. Two out of 11 eyes had PPV with in-the-bag IOL re-fixation. Out of 11, 2 eyes had PPV with IOL removal only. Remaining 2 eyes of 2 patients did not opt for surgery. Out of 11, 8 eyes had improved vision at last follow-up. Conclusions: In-the-bag dislocation of IOL is a rare late complication in uveitic eyes. With tight perioperative inflammatory control, scleral-fixated posterior chamber intraocular lens or IOL re-fixation are good options of restoring vision in these high-risk eyes.

  12. A novel full-angle scanning light scattering profiler to quantitatively evaluate forward and backward light scattering from intraocular lenses

    International Nuclear Information System (INIS)

    Walker, Bennett N.; James, Robert H.; Ilev, Ilko K.; Calogero, Don

    2015-01-01

    Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to light scatter. However, the specific direction that light scatters makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of scattered light is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning light scattering profiler (SLSP) as a novel approach capable of quantitatively evaluating the light scattering from IOLs with a nearly 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the light source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL light scatter

  13. A novel full-angle scanning light scattering profiler to quantitatively evaluate forward and backward light scattering from intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Bennett N., E-mail: bennett.walker@fda.hhs.gov [Optical Therapeutics and Medical Nanophotonics Laboratory, Office of Science and Engineering Laboratories, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States); Office of Device Evaluation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States); James, Robert H.; Ilev, Ilko K. [Optical Therapeutics and Medical Nanophotonics Laboratory, Office of Science and Engineering Laboratories, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States); Calogero, Don [Office of Device Evaluation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States)

    2015-09-15

    Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to light scatter. However, the specific direction that light scatters makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of scattered light is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning light scattering profiler (SLSP) as a novel approach capable of quantitatively evaluating the light scattering from IOLs with a nearly 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the light source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL light scatter.

  14. Intraocular pressure readings obtained through soft contact lenses using four types of tonometer.

    Science.gov (United States)

    Takenaka, Joji; Kunihara, Eriko; Rimayanti, Ulfah; Tanaka, Junko; Kaneko, Makoto; Kiuchi, Yoshiaki

    2015-01-01

    To compare the reliability and accuracy of intraocular pressure (IOP) measured while wearing soft contact lenses (SCLs) using a non-contact tonometer (NCT), Goldmann applanation tonometer (GAT), iCare rebound tonometer (RBT) and the Tono-Pen XL. Twenty-six healthy subjects were examined. The IOP was measured using NCT, GAT, RBT, and the Tono-Pen XL, while the subjects wore SCLs -5.00 D, -0.50 D and +5.00 D. Bland-Altman plots and a regression analysis were used to compare the IOPs obtained with those instruments and the IOPs of the naked eyes measured using GAT (the standard IOPs in this study). The IOPs obtained by the Tono-Pen XL while the subjects were wearing -5.00 D, -0.50 D, and +5.00 D SCLs were significantly higher than those of the naked eyes obtained using GAT. RBT showed that the IOPs were similar to the GAT standard IOPs under all conditions. The IOPs measured with NCT and GAT while the subjects were wearing -5.00 D and -0.50 D SCLs were similar to the GAT standard IOPs. The IOPs obtained with RBT and NCT while the subjects were wearing -5.00 D and -0.50 D SCLs exhibited a good correlation with the standard IOPs. The NCT and RBT are best when measuring IOP through hydrogel SCLs.

  15. Cionni ring and in-the-bag intraocular lens implantation for subluxated lenses: a prospective case series.

    Science.gov (United States)

    Vasavada, Abhay R; Praveen, Mamidipudi R; Vasavada, Viraj A; Yeh, Ru-Yin; Srivastava, Samaresh; Koul, Archana; Trivedi, Rupal H

    2012-06-01

    To report the intraoperative performance and postoperative outcomes of the Cionni-modified capsule tension ring (CTR) implantation in eyes with subluxated lenses. Prospective, observational case series. This study was carried out at Iladevi Cataract & IOL Research Centre, Ahmedabad, India. The study population comprised 41 eyes with subluxated lenses that underwent lens extraction, capsular bag fixation with modified CTR, and in-the-bag single-piece AcrySof intraocular lens (IOL) implantation. Main outcome measures were intraoperative performance and postoperative best-corrected visual acuity (BCVA), IOL centration, and complications. The mean age was 29.46 ± 16.16 years (3-68 years). Mean extent of subluxation was 6.1 ± 1.0 clock hours. Preoperatively, vitreous was detected in the anterior chambers of 5 eyes (12.2%). Two-port anterior chamber vitrectomy was performed in 2 eyes. Mean follow-up was 45.8 ± 2.9 months. Mean preoperative BCVA was 0.66 ± 0.22 logMAR (35 eyes). Mean postoperative BCVA at final follow-up was 0.33 ± 0.21 logMAR (41 eyes) (P IOL decentration was noted and repositioning was required in 2 eyes. Posterior capsule opacification developed in 14 eyes (34.2%); 12 eyes (29.3%) required Nd:YAG capsulotomy. Other complications included cystoid macular edema in 1 eye (2.4%), posterior synechiae in 1 eye (2.4%), and retinal detachment in 1 eye (2.4%). In-the-bag implantation of a Cionni-modified CTR with IOL appears to be a safe option in eyes with subluxated cataract, ensuring a stable IOL with few complications. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Comparison of outcomes with multifocal intraocular lenses: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Béatrice Cochener

    2011-01-01

    Full Text Available Béatrice Cochener1, Antoine Lafuma2, Babak Khoshnood2, Laurène Courouve2, Gilles Berdeaux3,41Centre Hospitalier Universitaire Brest, Brest, France; 2Cemka Eval, Bourg la Reine, France; 3Alcon France, Rueil-Malmaison, France; 4Conservatoire National des Arts et Métiers, Paris, FrancePurpose: To compare the clinical outcome of different multifocal intraocular lenses (IOLs based on information reported in the international literature.Methods: All comparative clinical trials that involved implanting at least one multifocal IOL in patients with cataract or presbyopia were extracted from the literature. Clinical outcomes included uncorrected near visual acuity, uncorrected distance visual acuity, visual acuity, spectacle independence, and halos. Random effects meta-analyses were conducted to compare outcomes for the different IOL types.Results: Twenty papers were identified describing 11 monofocal IOLs and 35 multifocal IOLs (19 diffractive, including 12 ReSTOR®, 14 refractive, and two accommodative patient cohorts. Multifocal and monofocal uncorrected distance visual acuity was 0.165 (0.090–0.240 and 0.093 (0.088–0.098, respectively. Compared with monofocal IOLs, multifocal IOLs produced better uncorrected near visual acuity (0.470 [0.322–0.618] versus 0.141 [0.131–0.152]; P < 0.0001, resulting in higher spectacle independence (incidence rate ratio [IRR] 3.62 [2.90–4.52]; P < 0.0001. Compared with refractive multifocal IOLs, diffractive multifocal IOLs produced a similar uncorrected distance visual acuity (0.105 [0.098–0.111] versus 0.085 [0.029–0.140]; P ≤ 0.78, not significant and better uncorrected near visual acuity (0.217 [0.118–0.317] versus 0.082 [0.067–0.098]; P < 0.0001 resulting in higher spectacle independence (IRR 1.75 [1.24–2.48]; P < 0.001. Compared with other multifocal IOLs, ReSTOR produced a better uncorrected distance visual acuity (0.067 [0.059–0.076] versus 0.093 [0.088–0.098]; P < 0.0001 and better

  17. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

    1997-01-01

    This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

  18. Comparison of hydrophobic and hydrophilic intraocular lens in preventing posterior capsule opacification after cataract surgery

    OpenAIRE

    Zhao, Yang; Yang, Ke; Li, Jiaxin; Huang, Yang; Zhu, Siquan

    2017-01-01

    Abstract Background: Posterior capsular opacification (PCO) is a common long-term complication of cataract surgery. Intraocular lens design and material have been implicated in influencing the development of PCO. This study evaluated the association of hydrophobic and hydrophilic intraocular lenses on preventing PCO. Methods: Medline, Cochrane, EMBASE, and Google Scholar databases were searched until August 3, 2016, using the following search terms: cataract, posterior capsule opacification, ...

  19. Comparison of clinical performance between trifocal and bifocal intraocular lenses: A meta-analysis.

    Science.gov (United States)

    Xu, Zequan; Cao, Danmin; Chen, Xu; Wu, Song; Wang, Xin; Wu, Qiang

    2017-01-01

    To compare the clinical performance between trifocal and bifocal intraocular lenses in bilateral cataract and/or refractive lens exchange (RLE) surgery. A comprehensive literature search of PubMed, EMBASE, Cochrane Controlled Trials Register and Web of Science was performed through October 2016 to identify randomized, controlled trials (RCTs) and comparative cohort studies. The primary outcomes were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), defocus curve, spectacle independence, patient satisfaction and contrast sensitivity. The secondary outcomes were residual sphere, spherical equivalent (SE), cylinder and complications. Six RCTs and 2 cohort studies including 568 eyes (278 in the trifocal group and 290 in the bifocal group) were identified. There was a statically significant difference between the two groups in UDVA (WMD: -0.03, 95% CI: -0.05 to -0.01, P = 0.005), but the difference (0.03 log MAR) is not clinically significant. Intermediate visual acuity was better in the trifocal IOL group judging from UIVA and defocus curves. There was a statically significant difference between the two groups in residual cylinder (WMD: 0.11, 95% CI: 0.02 to 0.20, P = 0.02), and subgroup AT Lisa tri 839MP trifocal also showed significant better UNVA than bifocal IOLs (WMD: -0.13, 95% CI: -0.17 to -0.08, Pbetter uncorrected near visual acuity than bifocal IOLs. However, more evidence is needed to compare their spectacle independence, higher satisfaction rate, and photic phenomena.

  20. Method for producing an isoplanatic aspheric monofocal intraocular lens, and resul ting lens

    OpenAIRE

    Barbero, Sergio; Marcos, Susana; Dorronsoro, Carlos; Montejo, Javier; Salazar Salegui, Pedro

    2010-01-01

    [EN] The invention can be used to obtain isoplanatic aspheric mono focal intraocular lenses in a viewing range of up to 25° (preferably up to 10°). The method comprises the following steps: l. mathematical defmition of an aphakic eye model; 2. mathematical definition of an intraocular lens model; 3. mathematical defmition of the implantation of the lens; 4. mathematical defmition of the merit function; 5. definition of the contour conditions; 6. defmition of a measurement for charact...

  1. Comparison of PMMA, foldable silicone and foldable acrylic hydrophobic intraocular lenses in combined phacoemulsification and trabeculectomy Comparação entre lentes intra-oculares de PMMA, lentes dobráveis de silicone e lentes acrílicas hidrofóbicas dobráveis em cirurgias combinadas de facoemulsificação e trabeculectomia

    Directory of Open Access Journals (Sweden)

    Ernani Serpa Junior

    2005-02-01

    Full Text Available PURPOSE: To compare the postoperative results of phacotrabeculectomy with implantation of PMMA, foldable silicone or foldable hydrofobic acrylic intraocular lens (IOL. SETTING: Glaucoma unit, The Royal Liverpool University Hospital, Liverpool, United Kingdom. METHODS: We studied a total of 124 eyes of three consecutive groups of patients with glaucoma and cataract that underwent phacotrabeculectomy with implantation of a PMMA (30 eyes, a foldable silicone (57 eyes or a foldable acrylic (37 eyes IOL. Postoperative Snellen visual acuity and intraocular pressure (IOP, and early and late complications were assessed. All data were analyzed by means of c² test, Fisher's exact test, ANOVA/MANOVA tests or a combination whenever appropriate. RESULTS: In all three groups the early and late mean postoperative IOPs were significantly lower than the preoperative ones (p25 mmHg and hypotony (IOPOBJETIVO: Comparar os resultados pós-operatórios de facotrabeculectomias com implante de lentes intra-oculares de PMMA, dobráveis de silicone e acrílicas hidrofóbicas dobráveis. MÉTODOS: Estudo comparativo retrospectivo, realizado no Departamento de Glaucoma da "St. Paul's Eye Unit - The Royal Liverpool University Hospital", em Liverpool, Inglaterra, onde foram estudados um total de 124 olhos de três grupos consecutivos de pacientes com glaucoma e catarata que foram submetidos à cirurgia de facotrabeculectomia com implante de lentes intra-oculares (LIO de PMMA (30 olhos, dobráveis de silicone (57 olhos e acrílicas hidrofóbicas dobráveis (37 olhos. Foram registradas a visão e pressão intra-ocular (PIO pré e pós-operatória, assim como as complicações pós-operatórias precoces e tardias. Todos os dados foram analisados utilizando-se o teste c², teste exato de Fisher, teste de ANOVA/MANOVA ou uma combinação deles quando necessário. RESULTADOS: Nos três grupos as PIOs pós-operatórias precoces e tardias foram significativamente inferiores

  2. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A.; Foreman, L.R.

    1997-07-08

    This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

  3. Photoprotection and photoreception of intraocular lenses under xenon and white LED illumination.

    Science.gov (United States)

    Artigas, J M; Navea, A; García-Domene, M C; Artigas, C; Lanzagorta, A

    2016-05-01

    To analyze the photoprotection and phototransmission that various intraocular lenses (IOLs) provide under the illumination of a xenon (Xe) lamp and white LEDs (light emitting diode). The spectral transmission curves of six representative IOLs were measured using a Perkin-Elmer Lambda 35 UV/VIS spectrometer. Various filtering simulations were performed using a Xe lamp and white LEDs. The spectral emissions of these lamps were measured with an ILT-950 spectroradiometer. The IOLs analyzed primarily show transmission of nearly 100% in the visible spectrum. In the ultraviolet (UV) region, the filters incorporated in the various IOLs did not filter equally, and some of them let an appreciable amount of UV through. The Xe lamp presented a strong emission of ultraviolet A (UVA), and its emission under 300nm was not negligible. The white LED did not present an appreciable emission under 380nm. The cut-off wavelength of most filters is between 380 and 400nm (Physiol Hydriol60C(®), IOLTECH E4T(®), Alcon SA60AT(®), Alcon IQ SN60WF(®)), so that their UV protection is very effective. Nonetheless, the IOL OPHTEC Oculaid(®) contains a filter that, when a Xe lamp is used, lets through up to 20% for 350nm and up to 15% for 300nm, which at this point is ultraviolet B (UVB). The OPHTEC(®) Artisan IOL has a transmission peak below 300nm, which must be taken into account under Xe illumination. White LEDs do not emit energy below 380nm, so no special protection is required in the UV region. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Evaluation of visual quality of spherical and aspherical intraocular lenses by Optical Quality Analysis System

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2017-06-01

    Full Text Available AIM: To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System (OQAS. METHODS: Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity (BCVA was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index (OSI was performed. RESULTS: There were no significant differences in visual acuity (P>0.05 before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA (r=-0.634, P=0.000, and positive corrections between the OSI value and the lens LOCUS III value of nucleus color (NC, nucleus opacity (NO, cortex (C and posterior lens capsular (P (r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=0.000, respectively. OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.5±0.8 before and 1d, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly (P<0.01 between the two groups. CONCLUSION: Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method.

  5. Calidad visual en pacientes con lente intraocular multifocal modelo OcuFlex operados de catarata The quality of vision in patients operated on from cataract and implanted with OcuFlex multifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Eneida Pérez Candelaria

    2010-01-01

    -operative periods, visual phenomena, centration and location of the intraocular lens and the subjective level of satisfaction of the patients were analyzed. The Excel Microsoft and Word 2003 for XP Windows-supported summary statistics were used. RESULTS: The postoperative average spheral equivalent was -0,59. For low and medium frequencies in binocular vision, average contrast sensitivity was 1,12 log unit in the preoperative and 1,74 log unit in the postoperative. The slit lamp-based biomicroscopy showed that 100% of cases had their intraocular lens centered and the ultrasound biomicroscopy yielded that in 93,75% of cases, the ILO was in the capsular sac. None of the patients mentioned the glare whereas just one patient (12,5% reported night halo vision. All the patients were satisfied. CONCLUSIONS: The multifocal lenses reduce the dependence of patients on glasses after cataract surgery. Therefore, this is a good choice for the recovery of optimal visual function.

  6. Prevention of increased abnormal fundus autofluorescence with blue light-filtering intraocular lenses.

    Science.gov (United States)

    Nagai, Hiroyuki; Hirano, Yoshio; Yasukawa, Tsutomu; Morita, Hiroshi; Nozaki, Miho; Wolf-Schnurrbusch, Ute; Wolf, Sebastian; Ogura, Yuichiro

    2015-09-01

    To observe changes in fundus autofluorescence 2 years after implantation of blue light-filtering (yellow-tinted) and ultraviolet light-filtering (colorless) intraocular lenses (IOLs). Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, and the Department of Ophthalmology, University of Bern, Bern, Switzerland. Prospective comparative observational study. Patients were enrolled who had cataract surgery with implantation of a yellow-tinted or colorless IOL and for whom images were obtained on which the fundus autofluorescence was measurable using the Heidelberg Retina Angiogram 2 postoperatively. The fundus autofluorescence in the images was classified into 8 abnormal patterns based on the classification of the International Fundus Autofluorescence Classification Group, The presence of normal fundus autofluorescence, geographic atrophy, and wet age-related macular degeneration (AMD) also was recorded. The fundus findings at baseline and 2 years postoperatively were compared. Fifty-two eyes with a yellow-tinted IOL and 79 eyes with a colorless IOL were included. Abnormal fundus autofluorescence did not develop or increase in the yellow-tinted IOL group; however, progressive abnormal fundus autofluorescence developed or increased in 12 eyes (15.2%) in the colorless IOL group (P = .0016). New drusen, geographic atrophy, and choroidal neovascularization were observed mainly in the colorless IOL group. The incidence of AMD was statistically significantly higher in the colorless IOL group (P = .042). Two years after cataract surgery, significant differences were seen in the progression of abnormal fundus autofluorescence between the 2 groups. The incidence of AMD was lower in eyes with a yellow-tinted IOL. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Visual performance after bilateral implantation of 2 new presbyopia-correcting intraocular lenses: Trifocal versus extended range of vision.

    Science.gov (United States)

    Monaco, Gaspare; Gari, Mariangela; Di Censo, Fabio; Poscia, Andrea; Ruggi, Giada; Scialdone, Antonio

    2017-06-01

    To compare the visual outcomes and quality of vision of 2 new diffractive multifocal intraocular lenses (IOLs) with those of a monofocal IOL. Fatebenefratelli e Oftalmico Hospital, Milan, Italy. Prospective case series. Patients had bilateral cataract surgery with implantation of a trifocal IOL (Panoptix), an extended-range-of-vision IOL (Symfony), or a monofocal IOL (SN60WF). Postoperative examinations included assessing distance, intermediate, and near visual acuity; binocular defocus; intraocular and total aberrations; point-spread function (PSF); modulation transfer function (MTF); retinal straylight; and quality-of-vision (QoV) and spectacle-dependence questionnaires. Seventy-six patients (152 eyes) were assessed for study eligibility. Twenty patients (40 eyes) in each arm of the study (60 patients, 120 eyes) completed the outcome assessment. At the 4-month follow-up, the trifocal group had significantly better near visual acuity than the extended-range-of-vision group (P = .005). The defocus curve showed the trifocal IOL had better intermediate/near performance than the extended-range-of-vision IOL and both multifocal IOLs performed better than the monofocal IOL. Intragroup comparison of the total higher-order aberrations, PSF, MTF, and retinal straylight were not statistically different. The QoV questionnaire results showed no differences in dysphotopsia between the multifocal IOL groups; however, the results were significantly higher than in the monofocal IOL group. Both multifocal IOLs seemed to be good options for patients with intermediate-vision requirements, whereas the trifocal IOL might be better for patients with near-vision requirements. The significant perception of visual side effects indicates that patients still must be counseled about these effects before a multifocal IOL is implanted. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Long-term outcomes of ciliary sulcus versus capsular bag fixation of intraocular lenses in children: An ultrasound biomicroscopy study.

    Directory of Open Access Journals (Sweden)

    Yun-E Zhao

    Full Text Available To evaluate the long-term outcomes of ciliary sulcus versus capsular bag fixation of intraocular lenses (IOLs in children after pediatric cataract surgery.IOL was implanted in the ciliary sulcus in 21 eyes of 14 children, and in the capsular bag in 19 eyes of 12 children for the treatment of pediatric cataract in an institutional setting. Ultrasound biomicroscopy (UBM was performed. Main outcome measures included IOL decentration, IOL tilt, anterior chamber depth (ACD, angle-opening distance at 500 μm (AOD500, trabecular-iris angle (TIA, best-corrected visual acuity (BCVA, intraocular pressure (IOP, and incidence of postoperative complications.The mean follow-up period was 6.81 ± 1.82 years. Comparing to the capsular bag fixation group, the ciliary sulcus fixation group had higher vertical IOL decentration, horizontal IOL tilt, and vertical IOL tilt (p = 0.02, 0.01,0.01, respectively, higher incidence of iris-IOL contact and peripheral anterior synechia (p = 0.001, 0.03, respectively, smaller ACD, AOD500, and TIA (p = 0.02, 0.03, 0.04, respectively, higher mean IOP (17.10 ±6.06 mmHg vs.14.15± 4.74 mmHg, p = 0.01, and higher incidence of secondary glaucoma (28.57% vs. 10.53%, p = 0.007.There was no significant difference between the two groups with regard to the BCVA, refractive errors, incidence of myopic shift, nystagmus, strabismus, and visual axis opacity.Ciliary sulcus fixation of IOLs in pediatric eyes may increase IOL malposition and crowding of the anterior segment, and may associate with a higher risk of secondary glaucoma compared to capsular bag fixation of IOLs.

  9. Visual outcome and changes in corneal endothelial cell density following aphakic iris-fixated intraocular lens implantation in pediatric eyes with subluxated lenses.

    Science.gov (United States)

    Siddiqui, Sorath Noorani; Khan, Ayesha

    2013-01-01

    To evaluate the visual outcome and corneal endothelial cell density after Artisan aphakic intraocular lens (IOL) implantation (Ophtec, Groningen, the Netherlands) in pediatric eyes with subluxated lenses. Artisan aphakic IOLs were implanted in 18 eyes of 11 children with subluxated lenses. Idiopathic subluxations and ectopia lentis due to Marfan syndrome were included, whereas subluxations due to trauma or buphthalmos were excluded. Best-corrected visual acuity (BCVA) and endothelial cell density were monitored. Mean postoperative BCVA and endothelial cell density at last follow-up visit were calculated. The age of children at the time of Artisan aphakic IOL implantation ranged from 8 to 16 years (mean: 11.58 ± 2.9 years). Mean follow-up was 9.12 ± 4.30 months. Mean postoperative logarithm of the minimum angle of resolution BCVA was 0.26 ± 0.13 (P = .001) and mean postoperative endothelial cell density was 2,860 ± 435 cells/mm(2) (P = .000). Mean endothelial cell loss was 17.1%. Artisan aphakic IOL implantation is a safe surgical choice in the management of ectopia lentis in the pediatric age group. It has minimal complications and is less traumatic to pediatric eyes. However, long-term follow-up of these children is required.[J Pediatr Ophthalmol Strabismus 2013;50(3):178-182.]. Copyright 2013, SLACK Incorporated.

  10. A contralateral eye study comparing apodized diffrative and full diffrative lenses: wavefront analysis and distance and near uncorrected visual acuity

    Directory of Open Access Journals (Sweden)

    Marcony Rodrigues de Santhiago

    2009-01-01

    Full Text Available PURPOSE: To evaluate intraindividual visual acuity, wavefront errors and modulation transfer functions in patients implanted with two diffractive multifocal intraocular lenses. METHODS: This prospective study examined 40 eyes of 20 cataract patients who underwent phacoemulsification and implantation of a spherical multifocal ReSTOR intraocular lens in one eye and an aspheric Tecnis ZM900 multifocal intraocular lens in the other eye. The main outcome measures, over a 3-month follow-up period, were the uncorrected photopic distance and near visual acuity and the defocus curve. The visual acuity was converted to logMAR for statistical analysis and is presented in decimal scale. The wavefront error and modulation transfer function were also evaluated in both groups. RESULTS: At the 3-month postoperative visit, the mean photopic distance uncorrected visual acuity (UCVA was 0.74 ± 0.20 in the ReSTOR group and 0.76 ± 0.22 in the Tecnis group (p=0.286. The mean near UCVA was 0.96 ± 0.10 in the ReSTOR group and 0.93 ± 0.14 in the Tecnis group (p=0.963. The binocular defocus curve showed measurements between the peaks better than 0.2 logMAR. The total aberration, higher-order aberration and coma aberration were not significantly different between the groups. The spherical aberration was significantly lower in the Tecnis group than in the ReSTOR group. (p=0.004. Both groups performed similarly for the modulation transfer function. CONCLUSION: The ReSTOR SN60D3 and Tecnis ZM 900 intraocular lenses provided similar photopic visual acuity at distance and near. The diffractive intraocular lenses studied provided a low value of coma and spherical aberrations, with the Tecnis intraocular lens having a statistically lower spherical aberration compared to the ReSTOR intraocular lens. In the 5 mm pupil diameter analyses, both intraocular lens groups showed similar modulation transfer functions.

  11. Effect of aspherical and yellow tinted intraocular lens on blue-on-yellow perimetry

    Directory of Open Access Journals (Sweden)

    Rodrigo França de Espíndola

    2012-10-01

    Full Text Available PURPOSE: To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL on contrast sensitivity and blue-on-yellow perimetry. METHODS: This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes received aspherical intraocular lens in one eye and spherical intraocular lens in the fellow eye; and 27 patients (54 eyes received ultraviolet and blue light filter (yellow tinted IOL implantation in one eye and acrylic ultraviolet filter IOL in the fellow eye. The primary outcome measures were contrast sensitivity and blue-on-yellow perimetry values (mean deviation [MD] and pattern standard deviation [PSD] investigated two years after surgery. The results were compared intra-individually. RESULTS: There was a statistically significant between-group (aspherical and spherical intraocular lens difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. There were no between-group significant differences (yellow tinted and clear intraocular lens under photopic or mesopic conditions. There was no statistically significant difference between all intraocular lens in MD or PSD. CONCLUSION: Contrast sensitivity was better under mesopic conditions with aspherical intraocular lens. Blue-on-yellow perimetry did not appear to be affected by aspherical or yellow tinted intraocular lens. Further studies with a larger sample should be carried out to confirm or not that hypotheses.

  12. Effects of intraocular lenses with different diopters on chromatic aberrations in human eye models.

    Science.gov (United States)

    Song, Hui; Yuan, Xiaoyong; Tang, Xin

    2016-01-11

    In this study, the effects of intraocular lenses (IOLs) with different diopters (D) on chromatic aberration were investigated in human eye models, and the influences of the central thickness of IOLs on chromatic aberration were compared. A Liou-Brennan-based IOL eye model was constructed using ZEMAX optical design software. Spherical IOLs with different diopters (AR40e, AMO Company, USA) were implanted; modulation transfer function (MTF) values at 3 mm of pupil diameter and from 0 to out-of-focus blur were collected and graphed. MTF values, measured at 555 nm of monochromatic light under each spatial frequency, were significantly higher than the values measured at 470 to 650 nm of polychromatic light. The influences of chromatic aberration on MTF values decreased with the increase in IOL diopter when the spatial frequency was ≤12 c/d, while increased effects were observed when the spatial frequency was ≥15 c/d. The MTF values of each IOL eye model were significantly lower than the MTF values of the Liou-Brennan eye models when measured at 555 nm of monochromatic light and at 470 to 650 nm of polychromatic light. The MTF values were also found to be increased with the increase in IOL diopter. With higher diopters of IOLs, the central thickness increased accordingly, which could have created increased chromatic aberration and decreased the retinal image quality. To improve the postoperative visual quality, IOLs with lower chromatic aberration should be selected for patients with short axial lengths.

  13. Intraocular Lens Calcification; a Clinicopathologic Report

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    Mozhgan Rezaei-Kanavi

    2009-04-01

    Full Text Available

    PURPOSE: To describe the clinical and pathological features of a case of hydrogel intraocular lens (IOL calcification. CASE REPORT: A 48-year-old man underwent explantation of a single-piece hydrophilic acrylic intraocular lens in his left eye because of decreased visual acuity and milky white opalescence of the IOL. The opacified lens was exchanged uneventfully with a hydrophobic acrylic IOL. Gross examination of the explanted IOL disclosed opacification of the optic and haptics. Full-thickness sections of the lens optic were stained with hematoxylin and eosin (H&E, von Kossa and Gram Tworts'. Microscopic examination of the sections revealed fine and diffuse basophilic granular deposits of variable size within the lens optic parallel to the lens curvature but separated from the surface by a moderately clear zone. The deposits were of high calcium content as evident by dark brown staining with von Kossa. Gram Tworts' staining disclosed no microorganisms. CONCLUSION: This report further contributes to the existing literature on hydrogel IOL calcification.

  14. Extreme depth-of-field intraocular lenses

    Science.gov (United States)

    Baker, Kenneth M.

    1996-05-01

    A new technology brings the full aperture single vision pseudophakic eye's effective hyperfocal distance within the half-meter range. A modulated index IOL containing a subsurface zeroth order coherent microlenticular mosaic defined by an index gradient adds a normalizing function to the vergences or parallactic angles of incoming light rays subtended from field object points and redirects them, in the case of near-field images, to that of far-field images. Along with a scalar reduction of the IOL's linear focal range, this results in an extreme depth of field with a narrow depth of focus and avoids the focal split-up, halo, and inherent reduction in contrast of multifocal IOLs. A high microlenticular spatial frequency, which, while still retaining an anisotropic medium, results in a nearly total zeroth order propagation throughout the visible spectrum. The curved lens surfaces still provide most of the refractive power of the IOL, and the unique holographic fabrication technology is especially suitable not only for IOLs but also for contact lenses, artificial corneas, and miniature lens elements for cameras and other optical devices.

  15. The measurement of intraocular pressure over positive soft contact lenses by rebound tonometry

    Directory of Open Access Journals (Sweden)

    Fabrizio Zeri

    2016-07-01

    Conclusions: Rebound tonometry over positive hydrogel CLs leads to a certain degree of IOP underestimation. This result did not change for the two positive lenses used in the experiment, despite their large difference in power and therefore in lens thickness. Optometrists should bear this in mind when measuring IOP with the rebound tonometer over plus power contact lenses.

  16. Toric Intraocular Lens Outcomes in Patients With Glaucoma.

    Science.gov (United States)

    Brown, Reay H; Zhong, Le; Bozeman, Caroline W; Lynch, Mary G

    2015-06-01

    To report the outcomes of toric intraocular lens implantation in patients with glaucoma and corneal astigmatism. One hundred twenty-six eyes of 87 patients with glaucoma and corneal astigmatism that underwent cataract surgery with an AcrySof toric intraocular lens (Alcon Laboratories, Inc., Fort Worth, TX) implant were selected for this single-center, retrospective case series. Corrected distance visual acuity, intraocular pressure, and refractive astigmatism were measured in each eye preoperatively and postoperatively. Uncorrected distance visual acuity and toric alignment were measured postoperatively. The uncorrected distance visual acuity was 0.04 ± 0.08 logMAR (20/22 Snellen) for all eyes. Ninety-eight percent of all eyes achieved an uncorrected distance visual acuity of 20/40 or better, with 76% achieving 20/25 or better and 47% achieving 20/20. The corrected distance visual acuity for all eyes was 0.01 ± 0.03 logMAR (20/20.5 Snellen) postoperatively. The refractive cylinder improved from 1.47 ± 1.10 diopters preoperatively to 0.31 ± 0.37 diopters postoperatively. The residual refractive cylinder was 1.00 diopter or less in 97% of eyes, 0.75 diopters or less in 90% of eyes, and 0.50 diopters or less in 83% of eyes. Mean misalignment was 4.4° ± 5.1°. Intraocular pressure decreased by a mean of 2.3 ± 3.3 mm Hg following the surgery. Toric intraocular lenses can reliably reduce astigmatism and improve uncorrected vision in eyes with cataract and glaucoma. Copyright 2015, SLACK Incorporated.

  17. Combining zonal refractive and diffractive aspheric multifocal intraocular lenses.

    Science.gov (United States)

    Muñoz, Gonzalo; Albarrán-Diego, César; Javaloy, Jaime; Sakla, Hani F; Cerviño, Alejandro

    2012-03-01

    To assess visual performance with the combination of a zonal refractive aspheric multifocal intraocular lens (MIOL) (Lentis Mplus, Oculentis GmbH) and a diffractive aspheric MIOL (Acri.Lisa 366, Acri.Tech GmbH). This prospective interventional cohort study comprised 80 eyes from 40 cataract patients (mean age: 65.5±7.3 years) who underwent implantation of the Lentis Mplus MIOL in one eye and Acri.Lisa 366 MIOL in the fellow eye. The main outcome measures were refraction; monocular and binocular uncorrected and corrected distance, intermediate, and near visual acuities; monocular and binocular defocus curves; binocular photopic contrast sensitivity function compared to a monofocal intraocular lens (IOL) control group (40 age-matched pseudophakic patients implanted with the AR-40e [Abbott Medical Optics]); and quality of vision questionnaire. Binocular uncorrected visual acuities were 0.12 logMAR (0.76 decimal) or better at all distances measured between 6 m and 33 cm. The Lentis Mplus provided statistically significant better vision than the Acri.Lisa at distances between 2 m and 40 cm, and the Acri.Lisa provided statistically significant better vision than the Lentis Mplus at 33 cm. Binocular defocus curve showed little drop-off at intermediate distances. Photopic contrast sensitivity function for distance and near were similar to the monofocal IOL control group except for higher frequencies. Moderate glare (15%), night vision problems (12.5%), and halos (10%) were reported. Complete independence of spectacles was achieved by 92.5% of patients. The combination of zonal refractive aspheric and diffractive aspheric MIOLs resulted in excellent uncorrected binocular distance, intermediate, and near vision, with low incidence of significant photic phenomena and high patient satisfaction. Copyright 2012, SLACK Incorporated.

  18. Using a slit lamp-mounted digital high-speed camera for dynamic observation of phakic lenses during eye movements: a pilot study

    Directory of Open Access Journals (Sweden)

    Leitritz MA

    2014-07-01

    Full Text Available Martin Alexander Leitritz, Focke Ziemssen, Karl Ulrich Bartz-Schmidt, Bogomil Voykov Centre for Ophthalmology, University Eye Hospital, Eberhard Karls University of Tübingen, Tübingen, Germany Purpose: To evaluate a digital high-speed camera combined with digital morphometry software for dynamic measurements of phakic intraocular lens movements to observe kinetic influences, particularly in fast direction changes and at lateral end points. Materials and methods: A high-speed camera taking 300 frames per second observed movements of eight iris-claw intraocular lenses and two angle-supported intraocular lenses. Standardized saccades were performed by the patients to trigger mass inertia with lens position changes. Freeze images with maximum deviation were used for digital software-based morphometry analysis with ImageJ.Results: Two eyes from each of five patients (median age 32 years, range 28–45 years without findings other than refractive errors were included. The high-speed images showed sufficient usability for further morphometric processing. In the primary eye position, the median decentrations downward and in a lateral direction were -0.32 mm (range -0.69 to 0.024 and 0.175 mm (range -0.37 to 0.45, respectively. Despite the small sample size of asymptomatic patients, we found a considerable amount of lens dislocation. The median distance amplitude during eye movements was 0.158 mm (range 0.02–0.84. There was a slight positive corrlation (r=0.39, P<0.001 between the grade of deviation in the primary position and the distance increase triggered by movements.Conclusion: With the use of a slit lamp-mounted high-speed camera system and morphometry software, observation and objective measurements of iris-claw intraocular lenses and angle-supported intraocular lenses movements seem to be possible. Slight decentration in the primary position might be an indicator of increased lens mobility during kinetic stress during eye movements

  19. The Visual Effects of Intraocular Colored Filters

    Directory of Open Access Journals (Sweden)

    Billy R. Hammond

    2012-01-01

    Full Text Available Modern life is associated with a myriad of visual problems, most notably refractive conditions such as myopia. Human ingenuity has addressed such problems using strategies such as spectacle lenses or surgical correction. There are other visual problems, however, that have been present throughout our evolutionary history and are not as easily solved by simply correcting refractive error. These problems include issues like glare disability and discomfort arising from intraocular scatter, photostress with the associated transient loss in vision that arises from short intense light exposures, or the ability to see objects in the distance through a veil of atmospheric haze. One likely biological solution to these more long-standing problems has been the use of colored intraocular filters. Many species, especially diurnal, incorporate chromophores from numerous sources (e.g., often plant pigments called carotenoids into ocular tissues to improve visual performance outdoors. This review summarizes information on the utility of such filters focusing on chromatic filtering by humans.

  20. [Management of post-traumatic aphakia and aniridia: Retrospective study of 17 patients undergoing scleral-sutured artificial iris intraocular lens implantation. Management of aphakia-aniridia with scleral-sutured artificial iris intraocular lenses].

    Science.gov (United States)

    Villemont, A-S; Kocaba, V; Janin-Manificat, H; Abouaf, L; Poli, M; Marty, A-S; Rabilloud, M; Fleury, J; Burillon, C

    2017-09-01

    To evaluate the long-term outcomes of artificial iris intraocular lenses sutured to the sclera for managing traumatic aphakia and aniridia. All consecutive cases receiving a Morcher ® combination implant from June 2008 to February 2016 in Edouard-Herriot Hospital (Lyon, France) were included in this single-center retrospective study. Visual acuity, subjective degree of glare, quality of life and surgical complications were evaluated. Seventeen eyes of 17 patients were included, among which 82% were male. The mean age was 42 years. The injuries consisted of 23.5% contusion and 70.5% open globe injuries, of which 41% were globe ruptures. There was one postoperative case. A penetrating keratoplasty was performed at the same time for eight eyes. The mean follow-up was 32 months. Best-corrected visual acuity improved in 41.2%, remained the same in 17.6% and decreased in 41.2% of our cases. Distance vision averaged 1±0.25 line better and near vision 2.2±0.32 lines better when visual acuity was quantifiable before surgery. Glare improved in 80% of patients and remained stable in 20%, decreasing on average from 3.3/5 [min. 3-max. 4; SD: 0.48] before surgery to 1.9/5 [min. 0-max. 4; SD: 1.197] after surgery. Regarding the esthetic results, 78% of the patients declared themselves reasonably to very satisfied; 57% reported no limitation of activities of daily living, and 43% reported mild limitation. Ocular hypertension and glaucoma, found in 40% of eyes, were the main postoperative complications. Implantation of prosthetic iris device combined with an intraocular lens appears to be safe and effective in reducing glare disability and improving visual acuity. Close, long-term monitoring is essential for the success of this surgery. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Laser iridotomy to treat uveitis-glaucoma-hyphema syndrome secondary to reverse pupillary block in sulcus-placed intraocular lenses: Case series.

    Science.gov (United States)

    Singh, Harmanjit; Modabber, Milad; Safran, Steven G; Ahmed, Iqbal Ike K

    2015-10-01

    To present cases of uveitis-glaucoma-hyphema (UGH) syndrome due to reverse pupillary block in sulcus-placed posterior chamber intraocular lenses (PC IOLs) that were managed with laser peripheral iridotomy (LPI). Community-based subspecialty clinics. Retrospective interventional case series. A chart review of patients with a sulcus-placed PC IOLs presenting with UGH syndrome and reverse pupillary block with posterior iris bowing as diagnosed by gonioscopy and anterior segment optical coherence tomography was carried out. Laser peripheral iridotomy was performed in the eyes included in the study. The main outcome measure was clinical resolution of UGH syndrome. The study included 6 eyes of 6 patients with a mean age of 59.8 years (range 43.0 to 66.0 years) who presented with unilateral UGH syndrome a mean of 28.7 months (range 0.3 to 84.0 months) after PC IOL implantation. All patients were previously myopic, with 5 (83.3%) having a history of vitrectomy. The mean axial length was 27.0 mm ± 1.4 (SD). An LPI was used to treat the reverse pupillary block with resultant improvement in iris profile and resolution of UGH syndrome in all eyes. The mean intraocular pressure decreased from 30.5 ± 10.0 mm Hg on 0.5 ± 0.8 glaucoma medications to 15.5 ± 3.2 mm Hg postoperatively on 0.7 ± 1.2 medications. The UGH syndrome due to reverse pupillary block occurred after sulcus-placed PC IOLs in susceptible patients, those with axial myopia, and post-vitrectomized eyes. The cases were managed with LPIs. Dr. Ahmed is a consultant to Alcon Laboratories, Inc. and Abbott Medical Optics, Inc. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  2. Reproducibility analysis of measurements with a mechanical semiautomatic eye model for evaluation of intraocular lenses

    Science.gov (United States)

    Rank, Elisabet; Traxler, Lukas; Bayer, Natascha; Reutterer, Bernd; Lux, Kirsten; Drauschke, Andreas

    2014-03-01

    Mechanical eye models are used to validate ex vivo the optical quality of intraocular lenses (IOLs). The quality measurement and test instructions for IOLs are defined in the ISO 11979-2. However, it was mentioned in literature that these test instructions could lead to inaccurate measurements in case of some modern IOL designs. Reproducibility of alignment and measurement processes are presented, performed with a semiautomatic mechanical ex vivo eye model based on optical properties published by Liou and Brennan in the scale 1:1. The cornea, the iris aperture and the IOL itself are separately changeable within the eye model. The adjustment of the IOL can be manipulated by automatic decentration and tilt of the IOL in reference to the optical axis of the whole system, which is defined by the connection line of the central point of the artificial cornea and the iris aperture. With the presented measurement setup two quality criteria are measurable: the modulation transfer function (MTF) and the Strehl ratio. First the reproducibility of the alignment process for definition of initial conditions of the lateral position and tilt in reference to the optical axis of the system is investigated. Furthermore, different IOL holders are tested related to the stable holding of the IOL. The measurement is performed by a before-after comparison of the lens position using a typical decentration and tilt tolerance analysis path. Modulation transfer function MTF and Strehl ratio S before and after this tolerance analysis are compared and requirements for lens holder construction are deduced from the presented results.

  3. Subluxation of iris-sutured intraocular lenses and results of a closed chamber technique for repositioning after penetrating keratoplasty.

    Science.gov (United States)

    Jabbur, Nada S; Akpek, Esen Karamursel; Stark, Walter J

    2005-05-01

    To describe subluxation of iris-fixated intraocular lenses (IOLs) after penetrating keratoplasty (PK) as a postoperative complication and report the long-term outcomes of a closed-chamber refixation technique used in the management. This was a retrospective, noncomparative interventional case series in which 19 consecutive patient charts with a subluxated iris-fixated IOL after PK were retrospectively reviewed. Fourteen of the patients underwent surgery using a closed-chamber refixation technique. These patients were evaluated for visual outcome and surgical complications associated with the procedure. In 13 patients, postoperative follow-up was available. In all 13 cases, the fixated IOL appeared stable and remained well positioned during a follow-up period of 56 months (range, 6-122). All patients (100%) achieved improved uncorrected visual acuity. The postoperative visual acuity ranged from 20/20 to 20/100 with a mean of 20/40. Vitreous hemorrhage occurred in 1 patient, and an additional patient required a second surgery using the same technique. Both of these patients did well with a final visual acuity of 20/40 and 20/50, respectively. Subluxation of iris-fixated IOL after PK can occur as a postoperative complication. The technique that we herein describe enables secure refixation of subluxated IOLs and yields favorable long-term results.

  4. Comparison of visual outcomes after bilateral implantation of extended range of vision and trifocal intraocular lenses.

    Science.gov (United States)

    Ruiz-Mesa, Ramón; Abengózar-Vela, Antonio; Aramburu, Ana; Ruiz-Santos, María

    2017-06-26

    To compare visual outcomes after cataract surgery with bilateral implantation of 2 intraocular lenses (IOLs): extended range of vision and trifocal. Each group of this prospective study comprised 40 eyes (20 patients). Phacoemulsification followed by bilateral implantation of a FineVision IOL (group 1) or a Symfony IOL (group 2) was performed. The following outcomes were assessed up to 1 year postoperatively: binocular uncorrected distance visual acuity (UDVA), binocular uncorrected intermediate visual acuity (UIVA) at 60 cm, binocular uncorrected near visual acuity (UNVA) at 40 cm, spherical equivalent (SE) refraction, defocus curves, mesopic and photopic contrast sensitivity, halometry, posterior capsule opacification (PCO), and responses to a patient questionnaire. The mean binocular values in group 1 and group 2, respectively, were SE -0.15 ± 0.25 D and -0.19 ± 0.18 D; UDVA 0.01 ± 0.03 logMAR and 0.01 ± 0.02 logMAR; UIVA 0.11 ± 0.08 logMAR and 0.09 ± 0.08 logMAR; UNVA 0.06 ± 0.07 logMAR and 0.17 ± 0.06 logMAR. Difference in UNVA between IOLs (pvisual outcomes. The FineVision IOL showed better near visual acuity. Predictability of the refractive results and optical performance were excellent; all patients achieved spectacle independence. The 2 IOLs gave similar and good contrast sensitivity in photopic and mesopic conditions and low perception of halos by patients.

  5. Ultraviolet-B phototoxicity and hypothetical photomelanomagenesis: intraocular and crystalline lens photoprotection.

    Science.gov (United States)

    Mainster, Martin A; Turner, Patricia L

    2010-04-01

    Ultraviolet-B (UV-B) radiation can cause phototoxic macular injuries in young people who have been sunbathing but not sungazing and in welders. Welders have a reportedly increased risk of uveal melanoma. We analyze phakic and pseudophakic risks for solar and welding arc UV-B exposure. Optical radiation measurement, analysis, and perspective. Spectral transmittances were measured for UV-transmitting, UV-blocking, and blue-blocking intraocular lenses (IOLs). The photoprotective performances of crystalline and intraocular lenses were analyzed using relevant epidemiologic and laboratory data and action spectra for acute retinal phototoxicity and melanoma photocarcinogenesis. Crystalline lens UV-B retinal protection is deficient in children and young adults, increasing their potential susceptibility to acute retinal phototoxicity and hypothetical photomelanomagenesis. UV-B radiation has sufficient energy/photon to induce primary melanomagenic DNA lesions, unlike blue light or UV-A radiation. UV-blocking and blue-blocking IOLs have negligible UV-B transmittance. UV-transmitting IOL transmittance of UV-B radiation is equivalent to that of a 15-year-old crystalline lens. If optical radiation exposure is responsible for welders' increased risk of uveal melanoma, then UV-B radiation is the most probable causative agent and spectacle wear is a potential confounding factor in epidemiologic studies of ocular melanoma. Welders under 30 years of age are at greater risk for welding maculopathy than older welders. Children, adults under 30 years of age, and pseudophakic individuals with UV-transmitting IOLs should wear sunglasses in bright environments because of the UV-B window in their crystalline lenses or IOLs. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Management of subluxated capsular bag-fixated intraocular lenses using a capsular anchor

    NARCIS (Netherlands)

    Ton, Yokrat; Naftali, Modi; Lapid Gortzak, Ruth; Assia, Ehud I.

    2016-01-01

    We describe the use of the capsular anchor (AssiAnchor) to manage a subluxated intraocular lens (IOL) in the capsular bag. The anchor comprises 2 prongs that hold the anterior lens capsule and a central rod that is sutured to the scleral wall, enabling centration of the IOL-capsular bag complex. Six

  7. Cauterization technique for suture erosion in transscleralfixation of intraocular lenses

    Directory of Open Access Journals (Sweden)

    Xu-Ting Hu

    2013-12-01

    Full Text Available Transscleral suturing is a commonly applied technique to fix intraocular implants in the sulcus. A major problem after transscleral implantation is suture erosion that normally happens in the late post-surgery period and may result in an increased incidence of endophthalmitis. Here we describe an original cauterization method by using a glass rod to melt the exposed suture end without damaging the suture knot in the sclera to avoid suture exposure in sclera-fixed IOL implantation. This is a simple, quick and effective technique that can be performed without conjunctiva incisions and will help to reduce suture erosion related complications.

  8. Influence of material and haptic design on the mechanical stability of intraocular lenses by means of finite-element modeling.

    Science.gov (United States)

    Remón, Laura; Siedlecki, Damian; Cabeza-Gil, Iulen; Calvo, Begoña

    2018-03-01

    Intraocular lenses (IOLs) are used in the cataract treatment for surgical replacement of the opacified crystalline lens. Before being implanted they have to pass the strict quality control to guarantee a good biomechanical stability inside the capsular bag, avoiding the rotation, and to provide a good optical quality. The goal of this study was to investigate the influence of the material and haptic design on the behavior of the IOLs under dynamic compression condition. For this purpose, the strain-stress characteristics of the hydrophobic and hydrophilic materials were estimated experimentally. Next, these data were used as the input for a finite-element model (FEM) to analyze the stability of different IOL haptic designs, according to the procedure described by the ISO standards. Finally, the simulations of the effect of IOL tilt and decentration on the optical performance were performed in an eye model using a ray-tracing software. The results suggest the major importance of the haptic design rather than the material on the postoperative behavior of an IOL. FEM appears to be a powerful tool for numerical studies of the biomechanical properties of IOLs and it allows one to help in the design phase to the manufacturers. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  9. Effect of Spherical Aberration on the Optical Quality after Implantation of Two Different Aspherical Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Michael Lasta

    2017-01-01

    Full Text Available Purpose. To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. Methods. 120 eyes of 60 patients underwent phacoemulsification. In patients’ eyes, an aberration-free IOL (Aspira-aA; Human Optics or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics was randomly implanted. After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed. Results. Contrast sensitivity was significantly higher in eyes with Aspira lens under mesopic conditions with 12 cycles per degree (CPD and under photopic conditions with 18 CPD (p=0.02. Wavefront measurements showed a higher total spherical aberration with a minimal pupil size of 4 mm in the Aspira group (0.05 ± 0.03 than in the Tecnis group (0.03 ± 0.02 (p=0.001. Strehl ratio was higher in eyes with Tecnis (0.28 ± 0.17 with a minimal pupil size larger than 5 mm than that with Aspira (0.16 ± 0.14 (p=0.04. In pupils with a minimum diameter of 4 mm spherical aberration had a significant effect on Strehl ratio, but not in pupils with a diameter less than 4 mm. Conclusions. Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. In contrast, this could not be shown in eyes with pupils under 4 mm or larger. This trial is registered with Clinicaltrials.gov NCT03224728.

  10. A stepwise approach for the management of capsular contraction syndrome in hinge-based accommodative intraocular lenses.

    Science.gov (United States)

    Page, Timothy P; Whitman, Jeffrey

    2016-01-01

    The aims of this study are to define the various stages of capsular contraction syndrome (CCS) and its effect on refractive error with hinge-based accommodating intraocular lenses (IOLs) and to describe a systematic approach for the management of the different stages of CCS. Hinge-based accommodative IOLs function via flexible hinges that vault the optic forward during accommodation. However, it is the flexibility of the IOL that makes it prone to deformation in the event of CCS. The signs of CCS are identified and described as posterior capsular striae, fibrotic bands across the anterior or posterior capsule, and capsule opacification. Various degrees of CCS may affect hinge-based accommodating IOLs in a spectrum from subtle changes in IOL appearance to significant increases in refractive error and loss of uncorrected visual acuity. The signs of CCS and its effect on IOL position and the resulting changes in refractive error are matched to appropriate treatment plans. A surgeon can avoid CCS and manage the condition if familiar with the early signs of CCS. If CCS is identified, yttrium-aluminum-garnet laser capsulotomy should be considered. If moderate CCS occurs, it may be effectively treated with insertion of a capsular tension ring. If CCS is allowed to progress to advanced stages, an IOL exchange may be necessary. Surgeons should be familiar with the stages of CCS and subsequent interventions. The steps outlined in this article help to guide surgeons in the prevention and management of CCS with hinge-based accommodative IOLs in order to provide improved refractive outcomes for patients.

  11. Microscopic and spectroscopic investigation of an explanted opacified intraocular lens

    Energy Technology Data Exchange (ETDEWEB)

    Simon, V., E-mail: viosimon@phys.ubbcluj.ro [Babeş-Bolyai University, Faculty of Physics and Interdisciplinary Research Institute on Bio-Nano-Sciences, 400084 Cluj-Napoca (Romania); Radu, T.; Vulpoi, A. [Babeş-Bolyai University, Faculty of Physics and Interdisciplinary Research Institute on Bio-Nano-Sciences, 400084 Cluj-Napoca (Romania); Rosca, C. [Optilens Clinic of Ophthalmology, 400604 Cluj-Napoca (Romania); Eniu, D. [Iuliu Haţieganu University of Medicine and Pharmacy, Department of Molecular Sciences, 400349 Cluj-Napoca (Romania)

    2015-01-15

    Highlights: • Changes on intraocular lens (IOL) surface after implantation. • Partial opacification of IOL central area. • Elemental composition on IOL surface prior to and after implantation. • First XPS depth profiling examination of the opacifying deposits. • Cell-mediated hydroxyapatite structuring. - Abstract: The investigated polymethylmethacrylate intraocular lens explanted an year after implantation presented a fine granularity consisting of ring-like grains of about 15 μm in diameter. In order to evidence the changes occurred on intraocular lens relative to morphology, elemental composition and atomic environments, microscopic and spectroscopic analyses were carried out using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), energy-dispersive X-ray (EDS), and X-ray photoelectron (XPS) spectroscopies. The results revealed that the grains contain hydroxyapatite mineral phase. A protein layer covers the lens both in opacified and transparent zones. The amide II band is like in basal epithelial cells. The shape and size of the grains, and the XPS depth profiling results indicate the possibility of a cell-mediated process involving lens epithelial cells which fagocitated apoptotic epithelial cells, and in which the debris derived from cell necrosis were calcified. To the best of our knowledge, this is the first investigation on explanted intraocular lenses using XPS depth profiling in order to examine the inside of the opacifying deposits.

  12. Acrylic acid surface-modified contact lens for the culture of limbal stem cells.

    Science.gov (United States)

    Zhang, Hong; Brown, Karl David; Lowe, Sue Peng; Liu, Guei-Sheung; Steele, David; Abberton, Keren; Daniell, Mark

    2014-06-01

    Surface treatment to a biomaterial surface has been shown to modify and help cell growth. Our aim was to determine the best surface-modified system for the treatment of limbal stem cell deficiency (LSCD), which would facilitate expansion of autologous limbal epithelial cells, while maintaining cultivated epithelial cells in a less differentiated state. Commercially available contact lenses (CLs) were variously surface modified by plasma polymerization with ratios of acrylic acid to octadiene tested at 100% acrylic acid, 50:50% acrylic acid:octadiene, and 100% octadiene to produce high-, mid-, and no-acid. X-ray photoelectron spectroscopy was used to analyze the chemical composition of the plasma polymer deposited layer. Limbal explants cultured on high acid-modified CLs outgrew more cells. Immunofluorescence and RT2-PCR array results indicated that a higher acrylic acid content can also help maintain progenitor cells during ex vivo expansion of epithelial cells. This study provides the first evidence for the ability of high acid-modified CLs to preserve the stemness and to be used as substrates for the culture of limbal cells in the treatment of LSCD.

  13. Serial corneal endothelial cell loss with lathe-cut and injection-molded posterior chamber intraocular lenses.

    Science.gov (United States)

    Kraff, M C; Sanders, D R; Lieberman, H L

    1983-01-01

    We compared endothelial cell loss of patients implanted with lathe-cut posterior chamber lenses and those implanted with injection-molded lenses over a three-year postoperative period. Results were based on more than 2,500 measurements of corneal endothelial density. Although the technique of cataract extraction (anterior chamber phacoemulsification, posterior chamber phacoemulsification, or planned extracapsular extraction) significantly affected cell loss (P less than .01), the type of implant (lathe-cut or injection-molded) did not. Significant continuing endothelial cell loss did not occur during the first three postoperative years with injection-molded lenses. There was, however, a statistically significant 7% to 15% additional cell loss after surgery over the first two to three postoperative years with lathe-cut implants. There have been no cases of corneal endothelial decompensation developing after implantation of injection-molded or lathe-cut lenses. Because a standard field clinical specular microscope was used in this study, cell counting errors cannot be ruled out as a cause of these findings.

  14. Low Cost DIY Lenses kit For High School Teaching

    Science.gov (United States)

    Thepnurat, Meechai; Saphet, Parinya; Tong-on, Anusorn

    2017-09-01

    A set of lenses was fabricated from a low cost materials in a DIY (Do it yourself) process. The purpose was to demonstrate to teachers and students in high schools how to construct lenses by themselves with the local available materials. The lenses could be applied in teaching Physics, about the nature of a lens such as focal length and light rays passing through lenses in either direction, employing a set of simple laser pointers. This instrumental kit was made from a transparent 2 mm thick of acrylic Perspex. It was cut into rectangular pieces with dimensions of 2x15 cm2 and bent into curved shape by a hot air blower on a cylindrical wooden rod with curvature radii of about 3-4.5 cm. Then a pair of these Perspex were formed into a hollow thick lenses with a base supporting platform, so that any appropriate liquids could be filled in. The focal length of the lens was measured from laser beam drawing on a paper. The refractive index, n (n) of a filling liquid could be calculated from the measured focal length (f). The kit was low cost and DIY but was greatly applicable for optics teaching in high school laboratory.

  15. Trifocal intraocular lenses: a comparison of the visual performance and quality of vision provided by two different lens designs

    Directory of Open Access Journals (Sweden)

    Gundersen KG

    2017-06-01

    Full Text Available Kjell G Gundersen,1 Rick Potvin2 1IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USA Purpose: To compare two different diffractive trifocal intraocular lens (IOL designs, evaluating longer-term refractive outcomes, visual acuity (VA at various distances, low contrast VA and quality of vision.Patients and methods: Patients with binocularly implanted trifocal IOLs of two different designs (FineVision [FV] and Panoptix [PX] were evaluated 6 months to 2 years after surgery. Best distance-corrected and uncorrected VA were tested at distance (4 m, intermediate (80 and 60 cm and near (40 cm. A binocular defocus curve was collected with the subject’s best distance correction in place. The preferred reading distance was determined along with the VA at that distance. Low contrast VA at distance was also measured. Quality of vision was measured with the National Eye Institute Visual Function Questionnaire near subset and the Quality of Vision questionnaire.Results: Thirty subjects in each group were successfully recruited. The binocular defocus curves differed only at vergences of −1.0 D (FV better, P=0.02, −1.5 and −2.00 D (PX better, P<0.01 for both. Best distance-corrected and uncorrected binocular vision were significantly better for the PX lens at 60 cm (P<0.01 with no significant differences at other distances. The preferred reading distance was between 42 and 43 cm for both lenses, with the VA at the preferred reading distance slightly better with the PX lens (P=0.04. There were no statistically significant differences by lens for low contrast VA (P=0.1 or for quality of vision measures (P>0.3.Conclusion: Both trifocal lenses provided excellent distance, intermediate and near vision, but several measures indicated that the PX lens provided better intermediate vision at 60 cm. This may be important to users of tablets and other handheld devices. Quality of vision appeared similar between the two lens designs

  16. Refractive Results: Safety and Efficacy of Secondary Piggyback Sensar™ AR40 Intraocular Lens Implantation to Correct Pseudophakic Refractive Error

    Directory of Open Access Journals (Sweden)

    Alahmady Hamad Alsmman Hassan

    2016-01-01

    Full Text Available In this study we evaluate the visual outcomes, safety, efficacy, and stability of implanting of second sulcus intraocular lens (IOL to correct unsatisfied ametropic patients after phacoemulsification. Methods. Retrospective study of 15 eyes (15 patients underwent secondary intraocular lens implanted into the ciliary sulcus. The IOL used was a Sensar IOL three-piece foldable hydrophobic acrylic IOL. The first IOL in all patients was acrylic intrabagal IOL implanted in uncomplicated phacoemulsification surgery. Results. Fifteen eyes (15 patients were involved in this study. Preoperatively, mean log⁡MAR UDVA and CDVA were 0.88 ± 0.22 and 0.19 ± 0.13, respectively, with a mean follow-up of 28 months (range: 24 to 36 months. At the end of the follow-up, all eyes achieved log⁡MAR UDVA of 0.20 ± 0.12 with postoperative refraction ranging from 0.00 to −0.50 D of attempted emmetropia. Conclusions. Implantation of the second sulcus SensarAR40 IOL was found to be safe, easy, and simple technique for management of ametropia following uncomplicated phacoemulsification.

  17. [Opacification of an intraocular lens: calcification of hydrophilic intraocular lenses after gas tamponade of the anterior chamber].

    Science.gov (United States)

    Schmidinger, G; Pemp, B; Werner, L

    2013-11-01

    A patient with endothelial dystrophy was treated with Descemet stripping automated endothelial keratoplasty (DSAEK) combined with cataract extraction and implantation of a hydrophilic intraocular lens (IOL, Lentis-L312, Oculentis) but visual acuity dropped from 0.15 logMAR to 0.52 logMAR 18 months later due to calcification of the IOL. With new methods of lamellar corneal transplantation being used more frequently the number of necessary anterior chamber tamponades with air/gas are increasing. In cataract cases in which a gas tamponade and transplantation might be necessary later on (cornea guttata), hydrophilic IOLs should be avoided.

  18. Iris-claw intraocular lenses to correct aphakia in the absence of capsule support.

    Science.gov (United States)

    De Silva, Samantha R; Arun, Kikkeri; Anandan, Maghizh; Glover, Nicholas; Patel, Chetan K; Rosen, Paul

    2011-09-01

    To evaluate the indications, postoperative visual efficacy, and complication rate after intraocular implantation of an iris-claw aphakic intraocular lens (IOL). Oxford Eye Hospital, Oxford, United Kingdom. Case series. This chart review comprised eyes with no capsule support that had anterior iris-fixation IOL implantation for aphakia between 2001 and 2009. The study comprised 116 eyes (104 patients). Iris-claw IOLs were inserted during primary lens surgery in 18 eyes (15.5%), during an IOL exchange procedure for dislocated posterior chamber IOLs in 19 eyes (16.4%), and as a secondary procedure in 79 eyes (68.1%). The mean follow-up was 22.4 months (range 3 to 79 months). The final corrected distance visual acuity (CDVA) was 6/12 or better in 68.9% of all eyes and in 47 of 53 eyes (88.7%) with no preoperative comorbidity. Complications included wound leak requiring resuturing in 2.6% of eyes, postoperative intraocular pressure rise in 9.5% of eyes (glaucoma escalation 0.8%), and cystoid macular edema in 7.7% of eyes (0.8% chronic). Iris-claw IOL subluxation occurred in 6.0% of eyes from 5 days to 60 months postoperatively; all the IOLs were repositioned. Corneal decompensation occurred in 1.7% of eyes; 0.8% had retinal detachments. Iris-claw IOL implantation for aphakia gave a good visual outcome and can be used for a wide range of indications. Postoperative complication rates were comparable to, if not better than, those with conventional anterior chamber IOLs. Correct implantation technique is critical in avoiding postoperative IOL subluxation. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. Lente intra-ocular opaca em diplopia intratável: relato de caso Opaque intraocular lens in intractable diplopia: case report

    Directory of Open Access Journals (Sweden)

    Fernanda Teixeira Krieger

    2006-08-01

    Full Text Available Diplopia intratável tem sido descrita em várias situações. Métodos convencionais como prismas e correção cirúrgica do estrabismo falham em neutralizá-la. O objetivo do trabalho é documentar o caso de uma paciente com estrabismo de longa data, cuja diplopia deteriorou-se ao longo dos anos, e não foi possível resolução com cirurgia, prisma, e oclusão com óculos e lente de contato com pupila opaca. A paciente foi então submetida à facoemulsificação com implante de lente intra-ocular opaca que atingiu o objetivo desejado.Intractable diplopia has been described in many situations but poor results are the rule with standard treatment modalities. The authors report a case of a woman with long-standing strabismus and diplopia who failed to improve following surgery, prism, and occlusive spectacles or contact lenses. Then, she was submitted to phacoemulsification and opaque intraocular lens implantation, which successfully neutralized diplopia.

  20. Evaluation of optical performance of 4 aspheric toric intraocular lenses using an optical bench system: Influence of pupil size, decentration, and rotation.

    Science.gov (United States)

    Kim, Min-Ji; Yoo, Young-Sik; Joo, Choun-Ki; Yoon, Geunyoung

    2015-10-01

    To evaluate the effect of pupil size, degree of intraocular lens (IOL) decentration, and rotation of 4 aspheric toric IOLs on the image quality. Department of Ophthalmology, Seoul St. Mary's Hospital, Seoul, South Korea. Experimental study. Four aspheric toric intraocular lenses (IOLs)-the Precizon (transitional conic toric IOL), AT Torbi 709M (bitoric IOL), SN6AT4 (posterior toric surface IOL), and ZCT225 (anterior toric surface IOL)-were evaluated using the optical bench metrology system. Measurements included changes in spherical aberrations, relative spherical equivalent (SE), and image quality at different pupil diameters and image quality degradation due to decentration and rotation of the IOLs. Change in relative SE with pupil size in aberration-free toric IOLs (transitional conic toric and bitoric IOLs) was greater than in negatively aspheric toric IOLs (posterior toric surface and anterior toric surface IOLs). In contrast, the aberration-free IOLs showed higher contrast than the negatively aspheric IOLs. When IOLs were decentered by 1.0 mm, the contrast reduction rates at 17.6 cycles per degree for the transitional conic toric IOL, bitoric IOL, posterior toric surface IOL, and anterior toric surface IOL were 5.1%, 3.1%, 12.2%, and 15.8%, respectively. Rotation-induced deterioration of contrast to 0.5 required a much higher rotation for the transitional conic toric IOL than for the other 3 IOLs. The transitional conic toric IOL and bitoric IOL provided superior image quality despite pupil size changes and the presence of decentration. The transitional conic toric IOL demonstrated maximum rotation tolerance compared with the other IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  1. Analysis of causes of intraocular lens explantations in the material of Department of Ophthalmology, Medical University of Lodz.

    Science.gov (United States)

    Wilczyński, Michał; Wilczyńska, Olena; Omulecki, Wojciech

    2009-01-01

    Implantation of intraocular lenses (IOLS) has become a standard practice in cataract surgery, however, similar to any other type of surgery, using IOLs is not complication-free and sometimes explantation of intraocular lenses may be necessary. This study was to gather data and analyze causes of intraocular lens explantations, performed in the Department of Ophthalmology, Medical University of Łódź. The data were gathered from medical documentation of all patients who underwent intraocular lens removal from January 2003 to July 2006. The examined group consisted of 16 patients (16 eyes): 9 women (fraction 0.56), and 7 men (fraction 0.44), at the age from 21 to 82 years (mean age 62.4 years, SD +/- 15.5). In all patients IOL explantation was performed under local, peribulbar anaesthesia. Two groups of patients were distinguished: patients who had an anterior chamber lens explanted (3 patients, fraction 0.19) and patients who underwent posterior chamber lens explantation (13 patients, fraction 0.81). Causes of AC IOL explantations were: vaulting of the IOL (1 eye, fraction 0.06), luxation of the IOL to the vitreous cavity (1 eye, fraction 0.06), and painful eyeball after anterior chamber lens implantation (1 eye, fraction 0.06). Causes of PC IOL explantations were: subluxation of the IOL (6 eyes, fraction 0.38), luxation of the lens to the vitreous cavity (3 eyes, fraction 0.19), luxation of the lens to the anterior chamber (1 eye, fraction 0.06), endophthalmitis (2 eyes, fraction 0.13) and incorrect lens power (1 eye, fraction 0.06). In the majority of eyes (n = 13, fraction 0.81) the removed implant was replaced by another intraocular lens, but 3 eyes (fraction 0.19) were left aphakic. We did not observe serious intra- or early postoperative complications which might influence the final result of the operation.

  2. Evaluation of rotation and visual outcomes after implantation of monofocal and multifocal toric intraocular lenses.

    Science.gov (United States)

    Garzón, Nuria; Poyales, Francisco; de Zárate, Begoña Ortíz; Ruiz-García, Jose Luis; Quiroga, Juan Antonio

    2015-02-01

    To evaluate rotational stability and its influence on postoperative visual acuity of different monofocal and multifocal toric intraocular lenses (IOLs). A prospective interventional study was designed. Ninety-one patients with a mean age of 71.65 ± 11.82 years were implanted with toric IOLs after phacoemulsification. Three monofocal toric IOLs (the Lentis LT [Oculentis, Berlin, Germany], enVista [Bausch & Lomb, Rochester, NY], and AcrySof IQ [Alcon Laboratories, Inc., Fort Worth, TX]) and one multifocal toric IOL (AcrySof IQ ReSTOR; Alcon Laboratories, Inc.) were implanted. Preoperative and postoperative images were taken to calculate the misalignment due to the marking method. To evaluate rotation in the different follow-up visits, another photograph was taken 1 hour and 1, 7 and 30 days postoperatively. Refraction, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity were measured 30 days postoperatively. Postoperative UDVA was 0.1 logMAR or better in 64.6% of eyes implanted with monofocal IOLs and 46.4% of eyes implanted with multifocal IOLs. The enVista toric IOL showed the best UDVA compared to the other monofocal IOLs, with 81% of eyes with 0.1 logMAR or better. The mean misalignment in the total group studied was 0.07° ± 0.60°; 69.6% of monofocal IOLs and 67.9% of multifocal IOLs showed less than 5° of rotation. A correlation was found between postoperative UDVA and rotation in the monofocal and multifocal IOLs implanted (r = 0.439 [P < .011] and = 0.787 [P = .001], respectively). At 1 month postoperatively, UDVA was slightly more affected by IOL rotation in multifocal than monofocal toric IOLs. The marking method was also effective. Copyright 2015, SLACK Incorporated.

  3. [Cause analysis and management of severe dislocated or subluxated intraocular lenses in the capsular bag].

    Science.gov (United States)

    Wang, Wen-qing; Jia, Li-Li; Lu, Bin; Fang, Jian; Chen, Ying

    2006-05-01

    To analyze the causes of severe dislocated and subluxated intraocular lenses (IOL) in capsular bag and the relevancy with abnormal capsular constitution. The abnormality of capsular and the position of IOL were retrospectively analyzed by slit lamp and microscope in dilated pupil. Surgeries were performed in all of 31 cases in order to exchange or reposit the dislocated or subluxated lOL. Among 31 cases, there were 20 cases with the dislocated or subluxated IOL in the earlier postoperative period and 11 cases in the later postoperative period. The subluxated IOL in 5 cases (16.1%) were caused by the large rupture of the posterior capsular, and by the rupture of the posterior capsular in 9 cases (29.0%). A upward subluxated IOL developed in one case (3.2%) as the result of small rupture in the equater capsular. The subluxatd IOL in the anterior chamber in two cases (6.5%) was induced by the radial rupture of residual anterior capsular. The size of the IOLs in 2 cases were not matched to the diameter of the capsule bag. The dislocated IOL into the vitreous in 2 cases was caused by the rupture of the superior capsular. The subluxated IOL in 2 cases (6.5%) was caused by the zonal finers rupture due to trauma. The severe disfiguration of the IOL haptic was found in one case. The dislocated IOL in 6 cases (19.4%) was caused by asymmetric capsular shrinkage. A subluxated IOL in one case was resulted from the zonular defects with pseudoexfoliation syndrome. The postoperative corrected visual acuity was 0.5 - 1.0 in 24 eyes, 0.1 - 0.4 in 6 eyes, and 0.05 in one eye. There are several causes for the dislocated or subluxated IOL. The correction of the IOL position should depend on the cause for the dislocated or subluxated IOL.

  4. Bilateral implantation of +2.5 D multifocal intraocular lens and contralateral implantation of +2.5 D and +3.0 D multifocal intraocular lenses: Clinical outcomes.

    Science.gov (United States)

    Nuijts, Rudy M M A; Jonker, Soraya M R; Kaufer, Robert A; Lapid-Gortzak, Ruth; Mendicute, Javier; Martinez, Cristina Peris; Schmickler, Stefanie; Kohnen, Thomas

    2016-02-01

    To assess the clinical visual outcomes of bilateral implantation of Restor +2.5 diopter (D) multifocal intraocular lenses (IOLs) and contralateral implantation of a Restor +2.5 D multifocal IOL in the dominant eye and Restor +3.0 D multifocal IOL in the fellow eye. Multicenter study at 8 investigative sites. Prospective randomized parallel-group patient-masked 2-arm study. This study comprised adults requiring bilateral cataract extraction followed by multifocal IOL implantation. The primary endpoint was corrected intermediate visual acuity (CIVA) at 60 cm, and the secondary endpoint was corrected near visual acuity (CNVA) at 40 cm. Both endpoints were measured 3 months after implantation with a noninferiority margin of Δ = 0.1 logMAR. In total, 103 patients completed the study (53 bilateral, 50 contralateral). At 3 months, the mean CIVA at 60 cm was 0.13 logMAR and 0.10 logMAR in the bilateral group and contralateral group, respectively (difference 0.04 logMAR), achieving noninferiority. Noninferiority was not attained for CNVA at 40 cm; mean values at 3 months for bilateral and contralateral implantation were 0.26 logMAR and 0.11 logMAR, respectively (difference 0.15 logMAR). Binocular defocus curves suggested similar performance in distance vision between the 2 groups. Treatment-emergent ocular adverse events rates were similar between the groups. Bilateral implantation of the +2.5 D multifocal IOL resulted in similar distance as contralateral implantation of the +2.5 D multifocal IOL and +3.0 D multifocal IOL for intermediate vision (60 cm), while noninferiority was not achieved for near distances (40 cm). Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. Tinting of intraocular lens implants

    International Nuclear Information System (INIS)

    Zigman, S.

    1982-01-01

    Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users

  6. Tinting of intraocular lens implants

    Energy Technology Data Exchange (ETDEWEB)

    Zigman, S.

    1982-06-01

    Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users.

  7. Tilt, Decentration, and Internal Higher-Order Aberrations of Sutured Posterior-Chamber Intraocular Lenses in Patients with Open Globe Injuries

    Directory of Open Access Journals (Sweden)

    Xiangjia Zhu

    2017-01-01

    Full Text Available Purpose. To evaluate the tilt, decentration, and internal higher-order aberrations (HOAs of sutured posterior-chamber intraocular lenses (IOLs in patients with open globe injuries. Methods. 46 consecutive patients (47 eyes who underwent transsclerally sutured IOL implantation were enrolled in this prospective cohort study. Nineteen eyes had a history of open globe injury. The tilt and decentration of the IOLs and the visual quality were measured 1 month after surgery. Results. The horizontal tilt and decentration of the IOLs in the open-globe-injury group were significantly higher than those in the control group (both P<0.05. In the open-globe-injury group, the horizontal decentration was significantly greater in the limbus-sclera-involved group (n=11 than in the only-cornea-involved group (n=8, P=0.040. The internal coma, 3rd-order, and total HOA values at pupil sizes of 4 mm (P=0.006 and 6 mm (P=0.013 were significantly higher in the open-globe-injury group than in the controls. Consequently, the optical quality data for the modulation transfer function and the Strehl ratio (all P<0.05 were significantly poorer in the open-globe-injury group. Conclusions. Open globe injuries damage the structural integrity of the eyeball, resulting in more-misaligned sutured IOLs and poorer visual quality.

  8. Magnifications of Single and Dual Element Accommodative Intraocular Lenses: Paraxial Optics Analysis

    Science.gov (United States)

    Ale, Jit B; Manns, Fabrice; Ho, Arthur

    2010-01-01

    Purpose Using an analytical approach of paraxial optics, we evaluated the magnification of a model eye implanted with single-element (1E) and dual-element (2E) translating-optics accommodative intraocular lenses (AIOL) with an objective of understanding key control parameters relevant to their design. Potential clinical implications of the results arising from pseudophakic accommodation were also considered. Methods Lateral and angular magnifications in a pseudophakic model eye were analyzed using the matrix method of paraxial optics. The effects of key control parameters such as direction (forward or backward) and distance (0 to 2 mm) of translation, power combinations of the 2E-AIOL elements (front element power range +20.0 D to +40.0 D), and amplitudes of accommodation (0 to 4 D) were tested. Relative magnification, defined as the ratio of the retinal image size of the accommodated eye to that of unaccommodated phakic (rLM1) or pseudophakic (rLM2) model eyes, was computed to determine how retinal image size changes with pseudophakic accommodation. Results Both lateral and angular magnifications increased with increased power of the front element in 2E-AIOL and amplitude of accommodation. For a 2E-AIOL with front element power of +35 D, rLM1 and rLM2 increased by 17.0% and 16.3%, respectively, per millimetre of forward translation of the element, compared to the magnification at distance focus (unaccommodated). These changes correspond to a change of 9.4% and 6.5% per dioptre of accommodation, respectively. Angular magnification also increased with pseudophakic accommodation. 1E-AIOLs produced consistently less magnification than 2E-AIOLs. Relative retinal image size decreased at a rate of 0.25% with each dioptre of accommodation in the phakic model eye. The position of the image space nodal point shifted away from the retina (towards the cornea) with both phakic and pseudophakic accommodation. Conclusion Power of the mobile element, and amount and direction of

  9. Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens.

    Science.gov (United States)

    Faria, Mun Yueh; Ferreira, Nuno Pinto; Pinto, Joana Medeiros; Sousa, David Cordeiro; Leal, Ines; Neto, Eliana; Marques-Neves, Carlos

    2016-01-01

    Nowadays, dislocated intraocular lenses (IOLs) and inadequate capsular support are becoming a challenge for every ophthalmic surgeon. Explantation of dislocated IOL and iris claw IOL (ICIOL) are the techniques that have been used in our ophthalmic department. The aim of this study is to report our technique for retropupillar ICIOL. This study is a retrospective case series. A total of 105 eyes with dislocated IOL from the patients at the Department of Ophthalmology in Santa Maria Hospital, a tertiary reference hospital in Lisbon, Portugal, from January 2012 until January 2016, had been analyzed. Of these 105 eyes, 66 eyes had dislocated one-piece IOL and 39 eyes had dislocated three-piece IOL. The latter underwent iris suture of the same IOL and were excluded from this study. The remaining 66 eyes with dislocated one-piece IOL underwent pars plana vitrectomy, that is, explantation of dislocated IOL through corneal incision and an implantation of retropupillary ICIOL. Operative data and postoperative outcomes included best corrected visual acuity, IOL position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, and anterior chamber depth. The mean follow-up was 23 months (range: 6-48 months). The mean preoperative best corrected visual acuity was 1.260±0.771 logMAR, and postoperative best corrected visual acuity was 0.352±0.400 logMAR units. Mean vision gain was 0.909 logMar units. The patients had the following complications: 1) retinal detachment was found in one patient, 2) corneal edema was found in three patients, 3) high intraocular pressure was observed in twelve patients, 4) subluxation of the IOL was observed in one patient, and 5) macular edema was found in three eyes. The results demonstrate that retropupillary ICIOL is an easy and effective method for the correction of aphakia in patients not receiving capsule support. The safety of this procedure must be interpreted in the context of a surgery usually indicated in

  10. Use of intraocular lenses in children with traumatic cataract in south India

    OpenAIRE

    Eckstein, M.; Vijayalakshmi, P; Killedar, M.; Gilbert, C.; Foster, A.

    1998-01-01

    AIMS—To assess the long term results of intraocular lens (IOL) implantation for traumatic cataract in young children in a developing country.
METHODS—Prospective hospital based study of 52 children (age 2-10 years) undergoing unilateral cataract extraction and IOL insertion for traumatic cataract performed by a single surgeon in south India. Children were reviewed regularly and followed up initially for 3 years.
RESULTS—There were no serious operative complications. Clinically significant pos...

  11. Intraocular Lens Use in an Astronaut During Long Duration Spaceflight.

    Science.gov (United States)

    Mader, Thomas H; Gibson, C Robert; Schmid, Josef F; Lipsky, William; Sargsyan, Ashot E; Garcia, Kathleen; Williams, Jeffrey N

    2018-01-01

    The purpose of this paper is to report the first use of an intraocular lens (IOL) in an astronaut during long duration spaceflight (LDSF). An astronaut developed a unilateral cataract and underwent phacoemulsification with insertion of an acrylic IOL. Approximately 15 mo later he flew on a Soyuz spacecraft to the International Space Station (ISS), where he successfully completed a 6-mo mission. Ocular examination, including ultrasound (US), was performed before, during, and after his mission and he was questioned regarding visual changes during each portion of his flight. We documented no change in IOL position during his space mission. This astronaut reported excellent and stable vision during liftoff, entry into microgravity (MG), 6 mo on the ISS, descent, and landing. Our results suggest that modern IOLs are stable, effective, and well tolerated during LDSF.Mader TH, Gibson CR, Schmid JF, Lipsky W, Sargsyan AE, Garcia K, Williams JN. Intraocular lens use in an astronaut during long duration spaceflight. Aerosp Med Hum Perform. 2018; 89(1):63-65.

  12. Influence on Visual Quality of Intraoperative Orientation of Asymmetric Intraocular Lenses.

    Science.gov (United States)

    Bonaque-González, Sergio; Ríos, Susana; Amigó, Alfredo; López-Gil, Norberto

    2015-10-01

    To evaluate visual quality when changing the intraocular orientation of the Lentis Mplus LS-312MF nonrotational symmetric +3.00 diopters aspheric multifocal intraocular lens ([IOL] Oculentis GmbH, Berlin, Germany) in normal eyes. An artificial eye was used to measure the in vitro wavefront of the IOL. The corneal topography of 20 healthy patients was obtained. For each eye, a computational analysis simulated the implantation of the IOL. The modulation transfer function (MTF) and an image quality parameter (visually modulated transfer function [VSMTF] metric) were calculated for a 5.0-mm pupil and for three conditions: distance, intermediate, and near vision. The procedure was repeated for each eye after a rotation of the IOL with respect to the cornea from 0° to 360° in 1° steps. Statistical analysis showed significant differences in mean VSMTF values between orientations for distance vision. Optimal orientation of the IOL (different for each eye) showed a mean improvement of 58% ± 19% (range: 20% to 121%) in VSMTF values with respect to the worst possible orientation. For these orientations, intermediate and near vision quality were statistically indistinguishable. The MTFs were different between orientations, showing a mean difference of approximately 5 cycles per degree in the maximum spatial frequencies that can be transferred between the best and the worst orientations for distance vision. The results suggest that implantation of this nonrotational symmetric IOL should improve visual outcomes if it is oriented to coincide with a customized meridian. A simple, practical method is proposed to find an approximation to the angle that an Mplus IOL should be inserted. Copyright 2015, SLACK Incorporated.

  13. A stepwise approach for the management of capsular contraction syndrome in hinge-based accommodative intraocular lenses

    Directory of Open Access Journals (Sweden)

    Page TP

    2016-06-01

    Full Text Available Timothy P Page,1 Jeffrey Whitman2 1Department of Ophthalmology, Oakland University William Beaumont School of Medicine, Royal Oak, MI, 2Key-Whitman Eye Center, Dallas, TX, USA Purpose: The aims of this study are to define the various stages of capsular contraction syndrome (CCS and its effect on refractive error with hinge-based accommodating intraocular lenses (IOLs and to describe a systematic approach for the management of the different stages of CCS. Methods: Hinge-based accommodative IOLs function via flexible hinges that vault the optic forward during accommodation. However, it is the flexibility of the IOL that makes it prone to deformation in the event of CCS. The signs of CCS are identified and described as posterior capsular striae, fibrotic bands across the anterior or posterior capsule, and capsule opacification. Various degrees of CCS may affect hinge-based accommodating IOLs in a spectrum from subtle changes in IOL appearance to significant increases in refractive error and loss of uncorrected visual acuity. The signs of CCS and its effect on IOL position and the resulting changes in refractive error are matched to appropriate treatment plans. Results: A surgeon can avoid CCS and manage the condition if familiar with the early signs of CCS. If CCS is identified, yttrium–aluminum–garnet laser capsulotomy should be considered. If moderate CCS occurs, it may be effectively treated with insertion of a capsular tension ring. If CCS is allowed to progress to advanced stages, an IOL exchange may be necessary. Conclusion: Surgeons should be familiar with the stages of CCS and subsequent interventions. The steps outlined in this article help to guide surgeons in the prevention and management of CCS with hinge-based accommodative IOLs in order to provide improved refractive outcomes for patients. Keywords: z-syndrome, pseudophakic tilt, IOL subluxation, CTR, capsular tension ring, capsular fibrosis

  14. Comparative analysis of skin sensitization potency of acrylates (methyl acrylate, ethyl acrylate, butyl acrylate, and ethylhexyl acrylate) using the local lymph node assay.

    Science.gov (United States)

    Dearman, Rebecca J; Betts, Catherine J; Farr, Craig; McLaughlin, James; Berdasco, Nancy; Wiench, Karin; Kimber, Ian

    2007-10-01

    There are currently available no systematic experimental data on the skin sensitizing properties of acrylates that are of relevance in occupational settings. Limited information from previous guinea-pig tests or from the local lymph node assay (LLNA) is available; however, these data are incomplete and somewhat contradictory. For those reasons, we have examined in the LLNA 4 acrylates: butyl acrylate (BA), ethyl acrylate (EA), methyl acrylate (MA), and ethylhexyl acrylate (EHA). The LLNA data indicated that all 4 compounds have some potential to cause skin sensitization. In addition, the relative potencies of these acrylates were measured by derivation from LLNA dose-response analyses of EC3 values (the effective concentration of chemical required to induce a threefold increase in proliferation of draining lymph node cells compared with control values). On the basis of 1 scheme for the categorization of skin sensitization potency, BA, EA, and MA were each classified as weak sensitizers. Using the same scheme, EHA was considered a moderate sensitizer. However, it must be emphasized that the EC3 value for this chemical of 9.7% is on the borderline between moderate (10%) categories. Thus, the judicious view is that all 4 chemicals possess relatively weak skin sensitizing potential.

  15. The effects of two different types of bandage contact lenses on the healthy canine eye.

    Science.gov (United States)

    Braus, Barbara Katharina; Riedler, Daniela; Tichy, Alexander; Spergser, Joachim; Schwendenwein, Ilse

    2018-02-06

    To compare two types of bandage contact lenses on the healthy canine eye. Six healthy Beagles. Two different types of bandage contact lenses (single sized human silicone contact lens 'PureVision 2' (Bausch & Lomb Incorporated, Rochester, NY, USA) and specially designed veterinary hydrogel contact lens 'AcriVet Pat D' (Bausch & Lomb Incorporated) were placed in 12 eyes of healthy Beagle dogs. Retention times and the effects of the lenses regarding irritation of the eye, changes in tear production, impact of contact lenses on tonometric readings, and cytologic and microbiological alterations of the canine eye were investigated. Mean retention times for veterinary hydrogel lenses with special dimensions were significantly shorter (2 days) than for one size human silicon lenses (8.8 days). Irritation scores were overall low for both types of lenses apart from one human lens causing severe irritation and keratoconjunctivitis as a sequel to folding and displacement. Tear production remained stable in human contact lenses. Intraocular pressure readings with a contact lens in place were only slightly altered; the most accurate readings were obtained through a human lens with an applanation tonometer. Cytology revealed a slight, nonsignificant increase in neutrophilic granulocytes with both types of lenses; the microflora did not change significantly. Human silicone lenses have significantly longer retention times and are less expensive than veterinary hydrogel lenses. In regard to irritation, bacterial growth and inflammation, both types of lenses can be recommended for use in canine eyes. © 2018 American College of Veterinary Ophthalmologists.

  16. Intraocular Ossification in the GSP/pe Chicken With Imperfect Albinism.

    Science.gov (United States)

    Shibuya, K; Kinoshita, K; Mizutani, M; Oshima, A; Yamashita, R; Matsuda, Y

    2015-07-01

    The eyes of 2 male and 2 female GSP/pe chickens, the imperfect albino strain, were investigated at 52 weeks of age. Aged chickens of the GSP/pe colony became blind with bilateral ocular enlargement and opaque lenses. Affected eyes (bilateral in 2 males and unilateral in 2 females) were hard and difficult to section; histologic specimens were processed after decalcification. A large portion of the posterior chamber was occupied by cancellous bone containing fibrous and cartilaginous foci. Osseous tissues developed adjacent to the choroid, and no retinal pigment epithelium (RPE) was detected between osseous tissues and the choroid. Small segments of degenerate neuronal retina were scattered in the osseous tissue. The irises and ciliary bodies were deformed by osseous tissue, and the lenses had severe cataracts. These observations suggest that the intraocular osseous tissue may be derived from RPE in the hereditary incomplete-albino strain of chickens. © The Author(s) 2014.

  17. Simulation of the Effect of Different Presbyopia-Correcting Intraocular Lenses With Eyes With Previous Laser Refractive Surgery.

    Science.gov (United States)

    Camps, Vicente J; Miret, Juan J; García, Celia; Tolosa, Angel; Piñero, David P

    2018-04-01

    To simulate the optical performance of three presbyopia-correcting intraocular lenses (IOLs) implanted in eyes with previous laser refractive surgery. A simulation of the through-focus modulation transfer function (MTF) was performed for three presbyopia-correcting IOLs (Mplus, Oculentis GmbH, Berlin, Germany; Symfony, Johnson & Johnson Vision, Santa Ana, CA; and Mini Well, SIFI S.p.A., Lavinaio, Italy) in one eye with previous myopic LASIK and another with hyperopic LASIK. Real topographic data and the wavefront aberration profile of each IOL obtained with a Hartmann-Shack sensor were used. In the eye with myopic LASIK, all IOLs lost optical quality at near and intermediate distances for 4- and 4.7-mm pupil size. For 3-mm pupil size, the Mini Well IOL showed the best intermediate and near MTF and maintained the far focus independently of the pupil. In the eye with hyperopic LASIK, the Mini Well IOL showed an intermediate, distance, and -4.00-diopter (D) foci for all pupils. The Symfony IOL showed a depth of focus at far and intermediate distance for 3-mm and a focus at -2.50 D in the rest. The Mplus showed a focus of -4.50 and -3.00 D for the 3- and 4-mm pupil, respectively. The Mini Well and Symfony IOLs seem to work better than the Mplus IOL in eyes with previous myopic LASIK. With previous hyperopic LASIK, the Mini Well IOL seems to be able to provide acceptable near, intermediate, and far foci for all pupil sizes. These findings should be confirmed in future clinical studies. [J Refract Surg. 2018;34(4):222-227.]. Copyright 2018, SLACK Incorporated.

  18. Efficacy and safety of multifocal intraocular lenses following cataract and refractive lens exchange: Metaanalysis of peer-reviewed publications.

    Science.gov (United States)

    Rosen, Emanuel; Alió, Jorge L; Dick, H Burkhard; Dell, Steven; Slade, Stephen

    2016-02-01

    We performed a metaanaysis of peer-reviewed studies involving implantation of a multifocal intraocular lens (IOL) in presbyopic patients with cataract or having refractive lens exchange (RLE). Previous reviews have considered the use of multifocal IOLs after cataract surgery but not after RLE, whereas greater insight might be gained from examining the full range of studies. Selected studies were examined to collate outcomes with monocular and binocular uncorrected distance, intermediate, and near visual acuity; spectacle independence; contrast sensitivity; visual symptoms; adverse events; and patient satisfaction. In 8797 eyes, the mean postoperative monocular uncorrected distance visual acuity (UDVA) was 0.05 logMAR ± 0.006 (SD) (Snellen equivalent 20/20(-3)). In 6334 patients, the mean binocular UDVA was 0.04 ± 0.00 logMAR (Snellen equivalent 20/20(-2)), with a mean spectacle independence of 80.1%. Monocular mean UDVA did not differ significantly between those who had a cataract procedure and those who had an RLE procedure. Neural adaptation to multifocality may vary among patients. Dr. Alió is a clinical research investigator for Hanita Lenses, Carl Zeiss Meditec AG, Topcon Medical Systems, Inc., Oculentis GmbH, and Akkolens International BV. Dr. Dell is a consultant to Bausch & Lomb and Abbott Medical Optics, Inc. Dr. Slade is a consultant to Alcon Surgical, Inc., Carl Zeiss Meditec AG, and Bausch & Lomb. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. HANGING BY A THREAD: THE LONG-TERM EFFICACY AND SAFETY OF TRANSSCLERAL SUTURED INTRAOCULAR LENSES IN CHILDREN (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

    Science.gov (United States)

    Buckley, Edward G.

    2007-01-01

    Purpose To evaluate the long-term efficacy, safety, and advisability of using transscleral sutured posterior chamber intraocular lenses (IOLs) in pediatric patients with no capsular support and to determine whether 10-0 polypropylene suture should be used for this purpose. Methods A long-term retrospective interventional case series review of 33 eyes of 26 patients who had a sutured IOL at Duke University Eye Center were evaluated for the intraoperative surgical risks, postoperative visual and refractive outcomes, and the number, type, and severity of the postoperative complications. In addition, a survey of pediatric ophthalmologists’ experience with suture breakage was performed. Results Postoperative visual acuity was significantly improved after surgery (P subluxation of the IOL secondary to spontaneous 10-0 polypropylene suture breakage at 3.5, 8, and 9 years after surgery. A survey of pediatric ophthalmologists revealed 10 similar cases (mean, 5 years after surgery). Conclusion Transscleral fixation of an IOL in a child appears to be a safe and effective procedure provided that the suture material used is stable enough to resist significant degradation over time. Caution should be exercised in the use of 10-0 polypropylene suture to fixate an IOL to the sclera in children, and an alternative material or size should be considered. PMID:18427618

  20. Comparison of clinical performance between trifocal and bifocal intraocular lenses: A meta-analysis.

    Directory of Open Access Journals (Sweden)

    Zequan Xu

    Full Text Available To compare the clinical performance between trifocal and bifocal intraocular lenses in bilateral cataract and/or refractive lens exchange (RLE surgery.A comprehensive literature search of PubMed, EMBASE, Cochrane Controlled Trials Register and Web of Science was performed through October 2016 to identify randomized, controlled trials (RCTs and comparative cohort studies. The primary outcomes were uncorrected distance visual acuity (UDVA, uncorrected intermediate visual acuity (UIVA, uncorrected near visual acuity (UNVA, defocus curve, spectacle independence, patient satisfaction and contrast sensitivity. The secondary outcomes were residual sphere, spherical equivalent (SE, cylinder and complications.Six RCTs and 2 cohort studies including 568 eyes (278 in the trifocal group and 290 in the bifocal group were identified. There was a statically significant difference between the two groups in UDVA (WMD: -0.03, 95% CI: -0.05 to -0.01, P = 0.005, but the difference (0.03 log MAR is not clinically significant. Intermediate visual acuity was better in the trifocal IOL group judging from UIVA and defocus curves. There was a statically significant difference between the two groups in residual cylinder (WMD: 0.11, 95% CI: 0.02 to 0.20, P = 0.02, and subgroup AT Lisa tri 839MP trifocal also showed significant better UNVA than bifocal IOLs (WMD: -0.13, 95% CI: -0.17 to -0.08, P<0.00001. However, no significant differences were observed in UNVA (WMD: -0.04, 95% CI: -0.11 to 0.02, P = 0.19, spectacle independence (WMD: 1.27, 95% CI: 0.89 to 18.15, P = 0.07, patient satisfaction (WMD: 4.01, 95% CI: 0.07 to 22.72, P = 0.87, residual sphere (WMD: -0.03, 95% CI: -0.18 to 0.13, P = 0.74, SE (WMD: 0.04, 95% CI: -0.09 to 0.16, P = 0.55 or complications (WMD: 2.08, 95% CI: 0.35 to 12.43, P = 0.42.Trifocal IOL technology (especially AT Lisa trifocal 839M trifocal had a clear advantage over bifocal IOLs in intermediate visual acuity, while both trifocal IOLs and

  1. Comparison of glare in YAG-damaged intraocular lenses: injection-molded versus lathe-cut.

    Science.gov (United States)

    Bath, P E; Dang, Y; Martin, W H

    1986-11-01

    A comparative analysis of YAG laser intraocular lens (IOL) damage was undertaken on injection-molded and lathe-cut IOLs. Damage sites were evaluated with polarized light. A consistent positive polarization was observed in the damage sites of lathe-cut IOLs. A consistent negative polarization was observed in the damage sites of injection-molded IOLs. The presence of positive polarization in IOL damage sites may be correlated with increased potential for glare. Results and clinical implications are discussed.

  2. Bilateral intraocular lens subluxation secondary to haptic angulation.

    Science.gov (United States)

    Moreno-Montañés, Javier; Fernández-Hortelano, Ana; Caire, Josemaría

    2008-04-01

    An 82-year-old man had uneventful phacoemulsification with bilateral implantation of a hydrophilic acrylic, single-piece intraocular lens (IOL) (ACR6D SE, Laboratoires Cornéal). Five years later, simultaneous and bilateral IOL subluxations occurred. In both eyes, the subluxation was situated on the side of one haptic that had moved forward (temporal area in the right eye and superior area in the left eye). In the right eye, the haptic-capsular bag was entrapped by the pupil and produced endothelial damage. A transscleral suture was placed over and under the subluxated haptic through the anterior and posterior capsules to capture the haptic. The haptic was then sutured to the sclera. No postoperative complications developed. We hypothesize that 10-degree angulated and broad haptic junctions can lead to zonular damage and IOL subluxation.

  3. Effects of blue light-filtering intraocular lenses on the macula, contrast sensitivity, and color vision after a long-term follow-up.

    Science.gov (United States)

    Kara-Junior, Newton; Espindola, Rodrigo F; Gomes, Beatriz A F; Ventura, Bruna; Smadja, David; Santhiago, Marcony R

    2011-12-01

    To evaluate the possible side effects and potential protection 5 years after implantation of an intraocular lens (IOL) with a blue-light filter (yellow tinted). Ophthalmology Department, University of São Paulo, São Paulo, Brazil. Prospective randomized clinical study. Patients with bilateral visually significant cataract randomly received an ultraviolet (UV) and blue light-filtering IOL (Acrysof Natural SN60AT) in 1 eye and an acrylic UV light-filtering only IOL (Acrysof SA60AT) in the fellow eye. The primary outcome measures were contrast sensitivity, color vision, and macular findings 5 years after surgery. The study enrolled 60 eyes of 30 patients. There were no significant clinical or optical coherence tomography findings in terms of age-related macular degeneration in any eye. There were no statistically significant differences in central macular thickness between the 2 IOL groups (P=.712). There were also no significant between-group differences under photopic or scotopic conditions at any spatial frequency studied. No statistically significant differences in the color discrimination test were found between the 2 IOL groups (P=.674). After 5 years, there were no significant differences in color perception, scotopic contrast sensitivity, or photopic contrast sensitivity between the blue light-filtering (yellow-tinted) IOL and the IOL with a UV-light filter only (untinted). The potential advantage of the tinted IOL in providing protection to macular cells remains unclear. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  4. Comparison of clinical outcomes between limbal relaxing incisions and toric intraocular lenses in eyes with astigmatic corneas

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    Giuliano de Oliveira Freitas

    2014-01-01

    Full Text Available Objective: To compare refractive and vectorial outcomes of limbal relaxing incisions (LRI versus toric intraocular lenses (IOL in the treatment of preexisting corneal astigmatism at the time of phacoemulsification. Methods: This longitudinal observational case series assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism between 0.75 and 2.50 diopters in both eyes. Patients were randomly assorted in two groups: one assigned to receive AcrySof Toric™ IOL in both eyes, and another one assigned to have AcrySof Natural™ IOL associated with LRI, also in both eyes. All patients were re-evaluated, postoperatively, at 1, 3 and 6 months, when refractive astigmatism analysis was performed using vectorial methods proposed by Thibos. Variability of outcomes within each group and between groups were assessed and compared. Results: Manifest refractive cylinder, in diopters (D, as means ± standard deviation, in the LRI group for 1-month, 3-month and 6-month re-evalutions were respectively -0.66 ± 0.30; -0.70 ± 0.21 and -0.74 ± 0.26 when compared to -0.58 ± 0.24; -0.63 ± 0.20, and -0.62 ± 0.17 in the toric IOL group. (p value ≥ 0.06. Vectorial analysis evidenced greater astigmatism reduction in the toric IOL group in the 6th postoperative month, when postoperative mean astigmatic power vector was 0.31 D, when compared to 0.37 D in the LRI group (p value = 0.00. Conclusions: A trend of slightly better refractive outcomes favoring toric IOL group was seen, although such a trend was not statistically significant. Vectorial analysis, however, suggests that the use of toric IOL may constitute a more advantageous approach in the treatment of pre-existing corneal astigmatism, simultaneously with phacoemulsification.

  5. [The influence of a new surface treatment of silicone intracoular lenses with fluoralkylsitan on the adherence of endophthalmitic bacteria in vitro

    Science.gov (United States)

    Kienast, A; Menz, D-H; Dresp, J; Klinger, M; Bunse, A; Ohgke, H; Solbach, W; Laqua, H; Kämmerer, R; Hoerauf, H

    2003-10-01

    Dynasilan is a fluoroalkylsilan which is able to bind to surface active molecules of intraocular lenses (IOLs), thereby offering a new option for surface modification of silicone lenses. The purpose of this in vitro study was to investigate the influence of this new surface treatment on the adherence of two typical endophthalmitis-inducing bacteria ( Staphylococcus epidermidis, Propionibacterium acnes). A total of 14 Dynasilan-treated and 14 untreated silicone lenses were incubated at 37 degrees C for 24 h in brain heart infusion broth (10(8) CFU/ml) either with Staphylococcus epidermidis or with Propionibacterium acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3 x 45 s. After a dilution series and incubation at 37 degrees C for 24 h or 3 days the colonies were counted. On untreated IOLs incubated with Staphylococcus epidermidis the average number of bacteria was 3.6 x 10(7)/ml, and on treated IOLs the number of counted colonies was reduced to 1.09 x 10(7)/ml. Incubated with Propionibacterium acnes the average number of adherent bacteria on untreated IOLs was 4.75 x 10(4)/ml and on modified IOLs the number was reduced to 2.94 x 10(4)/ml. Dynasilan surface treatment may reduce the adherence of Staphylococcus epidermidis and Propionibacterium acnes on silicone intraocular lenses. Further studies regarding the stability of this treatment, its biocompatibility and influence on lens epithelial cell adhesion are in progress.

  6. Light-distortion analysis as a possible indicator of visual quality after refractive lens exchange with diffractive multifocal intraocular lenses.

    Science.gov (United States)

    Brito, Pedro; Salgado-Borges, José; Neves, Helena; Gonzalez-Meijome, José; Monteiro, Manuel

    2015-03-01

    To study the perception of light distortion after refractive lens exchange (RLE) with diffractive multifocal intraocular lenses (IOLs). Clínica Oftalmológica das Antas, Porto, Portugal. Retrospective comparative study. Refractive lens exchange was performed with implantation of an AT Lisa 839M (trifocal) or 909MP (bifocal toric) IOL, the latter if corneal astigmatism was more than 0.75 diopter (D). The postoperative visual and refractive outcomes were evaluated. A prototype light-distortion analyzer was used to quantify the postoperative light-distortion indices. A control group of eyes in which a Tecnis ZCB00 1-piece monofocal IOL was implanted had the same examinations. A trifocal or bifocal toric IOL was implanted in 66 eyes. The control IOL was implanted in 18 eyes. All 3 groups obtained a significant improvement in uncorrected distance visual acuity (UDVA) (P refractive cylinder was less than 1.00 D in 86.7% of cases with the toric IOL. The mean light-distortion index was significantly higher in the multifocal IOL groups than in the monofocal group (P light-distortion index and CDVA. The multifocal IOLs provided excellent UDVA and functional UNVA despite increased light-distortion indices. The light-distortion analyzer reliably quantified a subjective component of vision distinct from visual acuity; it may become a useful adjunct in the evaluation of visual quality obtained with multifocal IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Effect of an ultraviolet-filtering intraocular lens on cystoid macular edema

    Energy Technology Data Exchange (ETDEWEB)

    Kraff, M.C.; Sanders, D.R.; Jampol, L.M.; Lieberman, H.L.

    1985-03-01

    A prospective double-masked study of 301 patients was undertaken to compare the effect of ultraviolet (UV) filtering in implant intraocular lenses (IOL) on the angiographic incidence of cystoid macular edema (CME) in patients undergoing extracapsular cataract extraction. Patients were randomized to receive either a posterior chamber IOL that contained UV-absorbing chromophore or an identical IOL which did not contain such a chromophore. All patients were scheduled for fluorescein angiography between three and six months after surgery; 228 angiograms were obtained that were readable for the presence or absence of angiographic CME. The mean interval following surgery was 4.3 months. The incidence of CME was 18.8% (21 of 112) in patients who received lenses without UV-filtering chromophore and 9.5% (11 of 116) in patients who received IOLs that contained UV-filtering chromophore. These findings show that UV-filtering-IOLs resulted in a statistically significant decrease in the incidence of CME. The presence or absence of the UV-filtering chromophore did not, however, significantly affect visual acuity in the early postoperative period.

  8. Biconvex intraocular lenses and Nd:YAG capsulotomy: Experimental comparison of surface damage with different poly(methyl methacrylate) formulations

    Energy Technology Data Exchange (ETDEWEB)

    Downing, J.E.; Alberhasky, M.T. (Greenview Hospital, Bowling Green, KY (USA))

    1990-11-01

    Biconvex posterior chamber lenses have optical advantages and decrease the risk of capsular opacification, but they are more likely to be pitted during ND:YAG capsulotomy because of apposition of the lens to the capsule. This study reports the likelihood of surface damage to different formulations of poly(methyl methacrylate) at the energy levels required to open posterior capsules. Molded lenses are more easily damaged than higher molecular weight lathe-cut materials (P less than .01), as expected. However, by keeping energy output low, even injection-molded lenses showed minimal damage, with mean pit size 39 +/- 39 microns at 1 mJ. By using a converging contact lens, low power, and keeping the focus behind the capsule, damage to all materials tested should be clinically insignificant.

  9. Ab-interno scleral suture loop fixation with cow-hitch knot in posterior chamber intraocular lens decentration

    Directory of Open Access Journals (Sweden)

    Ertugrul Can

    2016-01-01

    Full Text Available Aim of Study: To describe a simplified ab-interno cow-hitch suture fixation technique for repositioning decentered posterior chamber intraocular lens (PC IOL. Materials and Methods: Two cases are presented with the surgical correction of decentered and subluxated IOL. Ab-interno scleral suture fixation technique with hitch-cow knot in the eye was performed with a ciliary sulcus guide instrument and 1 year follow-up was completed. Results: Both of the patients had well centered lenses postoperatively. Corrected distant and near visual acuities of the patients were improved. There was no significant postoperative complication. In the follow-up period of 1 year, no evidence of suture erosion was found. Conclusions: Ab-interno scleral suture loop fixation with hitch-cow knot in the eye was effective in repositioning decentered or subluxated PC IOLs with excellent postoperative centered lenses and visual outcomes.

  10. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  11. Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

    Energy Technology Data Exchange (ETDEWEB)

    Olivares, M.; Castano, V.M. [Instituto de Fisica, UNAM, A.P. 1-1010, Queretaro, Mexico (Mexico); Molina, J.P.; Vazquez, F. [Facultad de Quimica UAEMex, Paseo Tollocan esq. Paseo Colon, Toluca, Estado de Mexico (Mexico)

    1998-12-31

    A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

  12. Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

    International Nuclear Information System (INIS)

    Olivares, M.; Castano, V.M.; Molina, J.P.; Vazquez, F.

    1998-01-01

    A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

  13. Primary anterior chamber intraocular lens for the treatment of severe crystalline lens subluxation.

    Science.gov (United States)

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2009-10-01

    Subluxated cataractous and clear lenses are commonly treated by limbal or pars plana lensectomy followed by primary or secondary intraocular lens (IOL) implantation. Adjunctive capsular prosthetic devices have facilitated lens removal and IOL centration in these challenging cases but have also added complexity and potential complications to the procedure. Although crystalline lens extraction may be required to clear the visual axis in mild to moderate lens subluxations, we propose insertion of a primary anterior chamber IOL without lens extraction in severe subluxations when the eye is optically aphakic or can be made functionally aphakic following neodymium:YAG laser zonulysis. Two cases demonstrating this approach are presented.

  14. Visual performance after the implantation of a new trifocal intraocular lens

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    Vryghem JC

    2013-10-01

    intraocular lenses improves the intermediate vision with minimal visual discomfort for the patient.Keywords: lens implantation, trifocal diffractive intraocular lens, third focus, diffractive multifocal

  15. Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens

    Directory of Open Access Journals (Sweden)

    Faria MY

    2016-08-01

    Full Text Available Mun Yueh Faria,1–3 Nuno Pinto Ferreira,1–3 Joana Medeiros Pinto,1–3 David Cordeiro Sousa,1–3 Ines Leal,1–3 Eliana Neto,1–3 Carlos Marques-Neves1–3 1Centro de Estudos da Visão, Universidade de Lisboa, 2Department of Ophthalmology, Hospital de Santa Maria, 3Faculty of Medicine, University of Lisbon, Lisbon, Portugal Background: Nowadays, dislocated intraocular lenses (IOLs and inadequate capsular support are becoming a challenge for every ophthalmic surgeon. Explantation of dislocated IOL and iris claw IOL (ICIOL are the techniques that have been used in our ophthalmic department. The aim of this study is to report our technique for retropupillar ICIOL.Methods: This study is a retrospective case series. A total of 105 eyes with dislocated IOL from the patients at the Department of Ophthalmology in Santa Maria Hospital, a tertiary reference hospital in Lisbon, Portugal, from January 2012 until January 2016, had been analyzed. Of these 105 eyes, 66 eyes had dislocated one-piece IOL and 39 eyes had dislocated three-piece IOL. The latter underwent iris suture of the same IOL and were excluded from this study. The remaining 66 eyes with dislocated one-piece IOL underwent pars plana vitrectomy, that is, explantation of dislocated IOL through corneal incision and an implantation of retropupillary ICIOL. Operative data and postoperative outcomes included best corrected visual acuity, IOL position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, and anterior chamber depth.Results: The mean follow-up was 23 months (range: 6–48 months. The mean preoperative best corrected visual acuity was 1.260±0.771 logMAR, and postoperative best corrected visual acuity was 0.352±0.400 logMAR units. Mean vision gain was 0.909 logMar units. The patients had the following complications: 1 retinal detachment was found in one patient, 2 corneal edema was found in three patients, 3 high intraocular pressure was observed in

  16. Fixed mydriatic pupil associated with an intraocular pressure rise as a complication of the implant of a Phakic Refractive Lens (PRL).

    Science.gov (United States)

    Pérez-Cambrodí, Rafael José; Piñero-Llorens, David Pablo; Ruiz-Fortes, Juan Pedro; Blanes-Mompó, Francisco Javier; Cerviño-Expósito, Alejandro

    2014-07-01

    We describe a case report of a patient that was implanted with a posterior chamber phakic intraocular lens (Phakic Refractive Lens, PRL) for the correction of moderate myopia and who developed postoperatively a fixed mydriasis compatible with an Urrets-Zavalia Syndrome (UZS). Specifically, a sudden acute increase of IOP in the left eye was observed in the immediate postoperative period. After IOP stabilization, the refractive result was good, but a fixed and mydriatic pupil appeared. This condition led the patient to experience visual discomfort, halos, and glare associated with high levels of higher-order aberrations in spite of the good visual result. A tinted-contact lens was fitted in order to minimize those symptoms. The UZS should be considered as a possible complication after implantation of posterior chamber phakic intraocular lenses.

  17. Visual outcome and optical quality after bilateral implantation of aspheric diffractive multifocal, aspheric monofocal and spherical monofocal intraocular lenses: a prospective comparison

    Directory of Open Access Journals (Sweden)

    Ke Yao

    2013-06-01

    Full Text Available AIM: To evaluate the visual function after bilateral implantation of aspheric diffractive multifocal Tecnis ZMA00, aspheric monofocal ZA9003 versus spherical monofocal Akreos Adapt intraocular lenses (IOLs.METHODS: Tecnis ZMA00, Tecnis ZA9003 or Akreos Adapt IOLs were bilaterally implanted in 180 eyes from 90 patients. The following parameters were assessed 3 months postoperatively: monocular and binocular uncorrected visual acuity (UCVA and distance-corrected visual acuity (DCVA for distance, intermediate and near, spherical aberration (SA, contrast and glare sensitivity, near point refractive power, uncorrected and best-corrected near stereoscopic acuity (NSA. Patient satisfaction was assessed by a questionnaire.RESULTS: Three months postoperatively, the monocular and binocular UCVA and DCVA at near of Tecnis ZMA00 were significantly better than other two groups. The mean SA for 5.0mm optical zone in Tecnis ZMA00 and Tecnis ZA9003 was significantly lower than that in Akreos Adapt. Mean contrast sensitivity and glare sensitivity were better for Tecnis ZA9003 group than for other two groups. Patients with Tecnis ZMA00 had higher monocular and binocular near point refractive power and uncorrected NSA than monofocal groups. The patients in Tecnis ZMA00 had higher mean values for halo compared with other two groups.CONCLUSION: Tecnis ZMA00 provided better near VA and uncorrected NSA and higher near point refractive power than monofocal IOLs and patients were spectacle independent. The IOLs with Tecnis aspheric design improved contrast and glare sensitivity. Patients with Tecnis ZMA00 reported more disturbances on visual phenomena of halo.

  18. Pathologic evidence of pseudoexfoliation in cases of in-the-bag intraocular lens subluxation or dislocation.

    Science.gov (United States)

    Liu, Erica; Cole, Scott; Werner, Liliana; Hengerer, Fritz; Mamalis, Nick; Kohnen, Thomas

    2015-05-01

    To provide complete histopathologic evaluation of explanted capsular bags that spontaneously dislocated in the late postoperative period, with the main objective being to assess the presence of pseudoexfoliation (PXF) material. Goethe-University Frankfurt, Frankfurt, Germany, and John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Retrospective case series. Standard gross and light microscopy and complete histopathology were performed on explanted subluxated and dislocated capsular bags containing an intraocular lens (IOL) or a capsular tension ring (CTR) and an IOL. Questionnaires were sent to explanting surgeons, and a patient chart review was performed, when available. The specimens were represented by capsular bags containing an IOL (n = 37) or an IOL-CTR (n = 3). The IOLs included 3-piece hydrophobic acrylic (n = 13), 1-piece hydrophobic acrylic (n = 7), 3-piece silicone (n = 6), 1-piece hydrophilic acrylic (n = 6), 3-piece hydrophilic acrylic (n = 2), and 1-piece poly(methyl methacrylate) (PMMA) (n = 6) designs; all CTRs were PMMA. Soemmering ring formation was mild in 8 specimens, moderate in 18 specimens, and severe in 14 specimens. Excessive contraction of the capsular bag with capsulorhexis phimosis was observed in 24 specimens. Twenty-six specimens had histopathologic evidence of PXF; 13 had a clinical history or evidence of PXF. Pseudoexfoliation might be implicated in a larger proportion of late in-the-bag IOL subluxations and dislocations than previously thought as a result of significant clinical underdiagnosis. This might indicate a need for new considerations during the preoperative and postoperative cataract surgery assessments and follow-up. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. Sutureless intrascleral intraocular lens fixation with lamellar dissection of scleral tunnel

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    Kawaji T

    2016-01-01

    Full Text Available Takahiro Kawaji,1,2 Tomoki Sato,2 Hidenobu Tanihara11Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Chuo-ku, 2Sato Eye & Internal Medicine Clinic, Kumamoto, JapanPurpose: To report the results of sutureless scleral fixation of a posterior chamber intraocular lens (IOL by using our developed simple technique.Methods: We retrospectively reviewed the medical records of 48 eyes of 47 patients who underwent sutureless intrascleral IOL fixation by using our modified technique. A 25-gauge microvitreoretinal knife was used to perform sclerotomies and create limbus-parallel scleral tunnels with lamellar dissection in which the haptics were fixed.Results: The IOLs were fixed and centered well. The mean follow-up period was 26.7 months. Postoperative complications included smooth vitreous hemorrhage in four eyes (8.3%, cystoid macular edema in two eyes (4.2%, and iris capture of the IOL in two eyes (4.2%. No other complications, such as breakage of the IOL, spontaneous IOL dislocation, or retinal detachment, were detected during the follow-up period.Conclusion: The lamellar dissection of the limbus-parallel scleral tunnel can simplify the forceps-assisted introduction of the haptics into the scleral tunnel, and this technique seemed to be safe.Keywords: intraocular lenses, ophthalmologic surgical procedures, intrascleral fixation, sutureless fixation

  20. 25G compared with 20G vitrectomy under Resight non-contact wide-angle lenses for Terson syndrome.

    Science.gov (United States)

    Mao, Xinbang; You, Zhipeng

    2017-08-01

    The aim of the present study was to compare the effectiveness of 25G vitrectomy to standard 20G vitrectomy for treatment of Terson syndrome under Resight non-contact wide-angle lenses. This was a case-control study of 20 patients with Terson syndrome (study group) that underwent 25G vitrectomy under Resight non-contact wide-angle lenses, with those of 20 matched patients that underwent 20G vitrectomy (control group). Medical records were reviewed from between July 2011 and October 2013. Data included results of the Early Treatment Diabetic Retinopathy Study examination, ophthalmology B-scan ultrasonography and fundus photography. The mean age, follow-up time, the preoperative visual acuity of LogMAR and the preoperative intraocular pressure (IOP) were all comparable in the two groups (all P>0.05). There were statistically significant differences in postoperative visual acuity of LogMAR compared with preoperative visual acuity (Pcontact wide-angle lenses can achieve a significantly shorter operative time and lower post-operative IOP compared with 20G Vitrectomy.

  1. Intraocular pressure reduction and regulation system

    Science.gov (United States)

    Baehr, E. F.; Burnett, J. E.; Felder, S. F.; Mcgannon, W. J.

    1979-01-01

    An intraocular pressure reduction and regulation system is described and data are presented covering performance in: (1) reducing intraocular pressure to a preselected value, (2) maintaining a set minimum intraocular pressure, and (3) reducing the dynamic increases in intraocular pressure resulting from external loads applied to the eye.

  2. Acrylate Systemic Contact Dermatitis.

    Science.gov (United States)

    Sauder, Maxwell B; Pratt, Melanie D

    2015-01-01

    Acrylates, the 2012 American Contact Dermatitis Society allergen of the year, are found in a range of products including the absorbent materials within feminine hygiene pads. When fully polymerized, acrylates are nonimmunogenic; however, if not completely cured, the monomers can be potent allergens.A 28-year-old woman is presented, who had her teeth varnished with Isodan (Septodont, Saint-Maur-des-Fossés, France) containing HEMA (2-hydroxyethyl methacrylate) with no initial reaction. Approximately 1 month later, the patient developed a genital dermatitis secondary to her feminine hygiene pads. The initial reaction resolved, but 5 months later, the patient developed a systemic contact dermatitis after receiving a second varnishing.The patient was dramatically patch test positive to many acrylates. This case demonstrates a reaction to likely unpolymerized acrylates within a feminine hygiene pad, as well as broad cross-reactivity or cosensitivity to acrylates, and possibly a systemic contact dermatitis with systemic re-exposure to unpolymerized acrylates.

  3. Synthesis of acrylic prepolymer

    International Nuclear Information System (INIS)

    Hussin bin Mohd Nor; Dahlan bin Haji Mohd; Mohamad Hilmi bin Mahmood.

    1988-04-01

    An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

  4. Intraocular (Eye) Melanoma—Health Professional Version

    Science.gov (United States)

    Intraocular (uveal) melanoma of the uveal tract (iris, ciliary body, and choroid), though rare, is the most common primary intraocular malignancy in adults. Find evidence-based information on intraocular melanoma treatment.

  5. Inability to perform posterior segment monitoring by scanning laser ophthalmoscopy or optical coherence tomography with some occlusive intraocular lenses in clinical use.

    Science.gov (United States)

    Yusuf, Imran H; Peirson, Stuart N; Patel, Chetan K

    2012-03-01

    To evaluate whether occlusive intraocular lenses (IOLs) produced by several manufacturers for clinical use equivalently transmit near-infrared (IR) light for scanning laser ophthalmoscopy (SLO) or optical coherence tomography (OCT) imaging. Nuffield Laboratory of Ophthalmology, Oxford University, United Kingdom. Evaluation of diagnostic test or technology. The study evaluated 6 black IOLs of 2 designs: 3 poly(methyl methacrylate) (PMMA) and 3 iris-claw anterior chamber IOLs. Each IOL was placed between a broad-spectrum white light source and a spectroradiometer to generate transmission spectra. Transmission in the near-IR range was examined using an 850 nm light-emitting diode. Scanning laser ophthalmoscopy or OCT imaging using Spectralis spectral-domain SLO or OCT was attempted through occlusive IOLs in a model eye. Artisan iris-claw and MS 612 PMMA occlusive IOLs totally occluded all wavelengths of light, including in the near IR range in which SLO and OCT imaging systems operate. It was not possible to capture SLO or OCT images through the iris-claw and PMMA occlusive IOLs in a model eye. Results suggest the property of near-IR transmission that permits SLO or OCT imaging through occlusive IOLs is restricted to the Morcher range of occlusive IOLs. Patients with non-near IR transmitting IOLs will not be able to receive detailed posterior segment monitoring with SLO or OCT. This finding may have a significant impact on preoperative occlusive IOL selection and the management of current patients with occlusive IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Application of diffractive aspheric multifocal intraocular lens in the Uighur in phacoemulsification

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    Nuersimanguli·Mijiti

    2016-05-01

    Full Text Available AIM:To research the efficacy and safety of diffractive aspheric multifocal intraocular lens(MIOLin the Uighur in phacoemulsification to provide guidance for the clinical treatment of cataracts patients in Xinjiang region. METHODS:Two hundred and twenty-eight Uygur patients(280 eyesreceived phacoemulsification from April 2012 to March 2013 were randomly divided into multifocal group(106 cases with 146 eyesand monofocal group(122 cases with 134 eyes. Patients were followed up for 3mo. The intraocular pressure(IOP, uncorrected distance visual acuity, uncorrected near vision, best-corrected distance visual acuity and best corrected near vision were measured. The delensed rate, visual quality, and satisfaction for lenses in the form of questionnaires were compared. RESULTS:Multifocal group was better on the uncorrected near vision than monofocal group(PP>0.05. The contrast sensitivity of multifocal group under scotopia at spatial frequency 3c/d was lower than that of monofocal group(PP>0.05. Delensed rate of multifocal group was higher than that of monofocal group(PP>0.05.CONCLUSION:MIOL with phacoemulsification can provide patient good full range vision, especially on good near vision. The patients with MIOL implanted have a higher delensed rate, less postoperative adverse symptoms, quicker recovery and satisfaction.

  7. In vivo subjective and objective longitudinal chromatic aberration after bilateral implantation of the same design of hydrophobic and hydrophilic intraocular lenses.

    Science.gov (United States)

    Vinas, Maria; Dorronsoro, Carlos; Garzón, Nuria; Poyales, Francisco; Marcos, Susana

    2015-10-01

    To measure the longitudinal chromatic aberration in vivo using psychophysical and wavefront-sensing methods in patients with bilateral implantation of monofocal intraocular lenses (IOLs) of similar aspheric design but different materials (hydrophobic Podeye and hydrophilic Poday). Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain. Prospective observational study. Measurements were performed with the use of psychophysical (480 to 700 nm) and wavefront-sensing (480 to 950 nm) methods using a custom-developed adaptive optics system. Chromatic difference-of-focus curves were obtained from best-focus data at each wavelength, and the longitudinal chromatic aberration was obtained from the slope of linear regressions to those curves. The longitudinal chromatic aberration from psychophysical measurements was 1.37 diopters (D) ± 0.08 (SD) (hydrophobic) and 1.21 ± 0.08 D (hydrophilic). From wavefront-sensing, the longitudinal chromatic aberration was 0.88 ± 0.07 D and 0.73 ± 0.09 D, respectively. At 480 to 950 nm, the longitudinal chromatic aberration was 1.27 ± 0.09 D (hydrophobic) and 1.02 ± 0.13 D (hydrophilic). The longitudinal chromatic aberration was consistently higher in eyes with the hydrophobic IOL than in eyes with the hydrophilic IOL (a difference of 0.16 D and 0.15 D, respectively). Similar to findings in young phakic eyes, the longitudinal chromatic aberration from the psychophysical method was consistently higher than from wavefront-sensing, by 0.48 D (35.41%) for the hydrophobic IOL and 0.48 D (39.43%) for the hydrophilic IOL. Longitudinal chromatic aberrations were smaller with hydrophilic IOLs than with hydrophobic IOLs of the same design. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Do blue-light filtering intraocular lenses affect visual function?

    Science.gov (United States)

    Lavric, Alenka; Pompe, Manca Tekavcic

    2014-11-01

    To study different aspects of visual function, macular changes, and subjective differences between the eye with an ultraviolet (UV) and blue-light filtering intraocular lens (IOL) and the fellow eye with a UV-light filtering IOL. Thirty patients (60 eyes) with senile cataract had both cataracts extracted, and an IOL was implanted at least 2 years before clinical evaluation. In one eye, AcrySof SA60AT (a UV-light filtering IOL) was implanted, whereas in the contralateral eye, AcrySof IQ SN60WF (a blue-light filtering IOL) was implanted. Each patient underwent visual acuity testing, color vision testing (Ishihara and Farnsworth-Munsell 100-hue tests), and contrast sensitivity (CS) testing. The macula was evaluated with optical coherence tomography and with clinical examination. Patients were asked if they noted any difference between the implanted IOLs concerning visual impression. Subjective visual quality was evaluated using the National Eye Institute Visual Functioning Questionnaire. There was a borderline statistically significant difference in the mean best-corrected visual acuity (p = 0.05). As regards color vision, no significant changes in Ishihara and Farnsworth-Munsell 100-hue error scores were detected between both eyes (p = 0.48 and p = 0.59, respectively). Analysis of CS showed no significant difference between the groups at any spatial frequency. There were also no statistically significant differences in central macular thickness and total macular volume between the two IOL groups (p = 0.72 and p = 0.61, respectively). In both IOL groups, three eyes developed an epiretinal membrane, and six eyes developed early signs of age-related macular degeneration. This study showed no significant effects of a blue-light filtering IOL on visual acuity and no influence on color perception and CS. After more than 2 years, there were no significant differences in macular changes between the IOL groups. Clinical evidence of the effect of a blue-light filtering IOL on

  9. Effect of aspherical and yellow tinted intraocular lens on blue-on-yellow perimetry Efeito das lentes intraoculares asféricas e com pigmentação amarela na campimetria azul-amarelo

    Directory of Open Access Journals (Sweden)

    Rodrigo França de Espíndola

    2012-10-01

    Full Text Available PURPOSE: To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL on contrast sensitivity and blue-on-yellow perimetry. METHODS: This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes received aspherical intraocular lens in one eye and spherical intraocular lens in the fellow eye; and 27 patients (54 eyes received ultraviolet and blue light filter (yellow tinted IOL implantation in one eye and acrylic ultraviolet filter IOL in the fellow eye. The primary outcome measures were contrast sensitivity and blue-on-yellow perimetry values (mean deviation [MD] and pattern standard deviation [PSD] investigated two years after surgery. The results were compared intra-individually. RESULTS: There was a statistically significant between-group (aspherical and spherical intraocular lens difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. There were no between-group significant differences (yellow tinted and clear intraocular lens under photopic or mesopic conditions. There was no statistically significant difference between all intraocular lens in MD or PSD. CONCLUSION: Contrast sensitivity was better under mesopic conditions with aspherical intraocular lens. Blue-on-yellow perimetry did not appear to be affected by aspherical or yellow tinted intraocular lens. Further studies with a larger sample should be carried out to confirm or not that hypotheses.OBJETIVO: Investigar a possibilidade de efeitos na sensibilidade ao contraste e nos resultados da campimetria azul-amarelo com implante de uma lente intraocular (LIO asférica ou de pigmentação amarela. MÉTODOS: Trata-se de um estudo prospectivo, randomizado, duplo-mascarado, envolvendo 52 pacientes portadores de catarata senil bilateral, divididos em dois grupos; 25

  10. [Acrylic resin removable partial dentures].

    Science.gov (United States)

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  11. [Correlation of intraocular pressure variation after visual field examination with 24-hour intraocular pressure variations in primary open-angle glaucoma].

    Science.gov (United States)

    Noro, Takahiko; Nakamoto, Kenji; Sato, Makoto; Yasuda, Noriko; Ito, Yoshinori; Ogawa, Shumpei; Nakano, Tadashi; Tsuneoka, Hiroshi

    2014-10-01

    We retrospectively examined intraocular pressure variations after visual field examination in primary open angle glaucoma (POAG), together with its influencing factors and its association with 24-hour intraocular pressure variations. Subjects were 94 eyes (52 POAG patients) subjected to measurements of 24-hour intraocular pressure and of changes in intraocular pressure after visual field examination using a Humphrey Visual Field Analyzer. Subjects were classified into three groups according to the magnitude of variation (large, intermediate and small), and 24-hour intraocular pressure variations were compared among the three groups. Factors influencing intraocular pressure variations after visual field examination and those associated with the large variation group were investigated. Average intraocular pressure variation after visual field examination was -0.28 ± 1.90 (range - 6.0(-) + 5.0) mmHg. No significant influencing factors were identified. The intraocular pressure at 3 a.m. was significantly higher in the large variation group than other two groups (p field examination. Increases in intraocular pressure during the night might be associated with large intraocular pressure variations after visual field examination.

  12. Associated depression in pseudophakic patients with intraocular lens with and without chromophore

    Directory of Open Access Journals (Sweden)

    Mendoza-Mendieta ME

    2016-03-01

    Full Text Available María Elena Mendoza-Mendieta, Ana Aurora Lorenzo-Mejía Association to Prevent Blindness in Mexico (APEC, Hospital “Dr Luis Sánchez Bulnes”, Mexico City, Mexico Background: With aging, the crystalline lens turns yellowish, which increases the absorption of wavelengths in the blue electromagnetic spectrum, reducing their photoreception in the retina. Since these wavelengths are the main stimulus in the regulation of the circadian rhythm, progressive reduction in their transmission is associated with chronic sleep disturbances and depression in elderly patients. Cataract extraction improves circadian photoreception at any age. However, lenses that block blue waves have 27% to 38% less melatonin suppression than lenses that block only ultraviolet (UV rays. Purpose: To assess the depression symptoms in subjects who have had bilateral phacoemulsification and intraocular lens (IOL implants, one group with yellow chromophore IOLs and the other group with transparent IOLs were compared. Setting: Association to Prevent Blindness in Mexico (APEC, Hospital “Dr Luis Sánchez Bulnes”. Design: This was an observational, cross-sectional, and single-center study. Materials and methods: Twenty-six subjects between 60 and 80 years of age, with a history of bilateral phacoemulsification and placement of the same type of IOL in both eyes from 4 to 12 months prior to the study, who attended the follow-up visits and agreed to participate in this study, and provided signed informed consent were included in the study. They were asked to answer the short version of the 15-item Geriatric Depression Scale. Results: The average age of the study participants was 72.5±5.94 years. The group without chromophore included 46.1% (n=12 of the patients and the group with chromophore included 53.9% (n=14 of the patients (P=0.088. Conclusion: In the group of patients with IOLs that block the passage of blue light, the depression rate was 21.4%, a rate similar to that

  13. Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal; Koester, Benjamin P.; Sharon, Keren; Bayliss, Matthew

    2009-01-29

    We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model of the lensing cluster Abell 1703 with constraints from multiple image families, and find the dark matter inner density profile to be cuspy with the slope consistent with -1, in agreement with expectations.

  14. Phakic iris-fixated intraocular lens placement in the anterior chamber: effects on aqueous flow.

    Science.gov (United States)

    Repetto, Rodolfo; Pralits, Jan O; Siggers, Jennifer H; Soleri, Paolo

    2015-05-01

    Phakic intraocular lenses (pIOLs) are used for correcting vision; in this paper we investigate the fluid dynamical effects of an iris-fixated lens in the anterior chamber. In particular, we focus on changes in the wall shear stress (WSS) on the cornea and iris, which could be responsible for endothelial and pigment cell loss, respectively, and also on the possible increase of the intraocular pressure, which is known to correlate with the incidence of secondary glaucoma. We use a mathematical model to study fluid flow in the anterior chamber in the presence of a pIOL. The governing equations are solved numerically using the open source software OpenFOAM. We use an idealized standard geometry for the anterior chamber and a realistic geometric description of the pIOL. We consider separately the main mechanisms that produce fluid flow in the anterior chamber. The numerical simulations allow us to obtain a detailed description of the velocity and pressure distribution in the anterior chamber, and indicated that implantation of the pIOL significantly modifies the fluid dynamics in the anterior chamber. However, lens implantation has negligible influence on the intraocular pressure and does not produce a significant increase of the shear stress on the cornea, while the shear stress on the iris, although increased, is not enough to cause detachment of cells. We conclude that alterations in the fluid dynamics in the anterior chamber as a result of lens implantation are unlikely to be the cause of medical complications associated with its use.

  15. Capsule-Fixated Intraocular Lens Implantation in Small Pupil Cases.

    Science.gov (United States)

    Schojai, Merita; Schultz, Tim; Burkhard Dick, H

    2017-08-01

    To describe a new technique for implantation of capsule-fixated intraocular lenses (IOLs) (FEMTIS; Oculentis, Berlin, Germany) in patients with small pupils. In 4 eyes with small pupils, an anterior capsule-fixated IOL was implanted into the capsular bag after femtosecond laser treatment. The two large and two small flaps of the IOL were elevated to the front of the iris and the anterior capsule. Finally, the iris was flipped over the flaps to ensure a fixation of the capsule inside of the capsulotomy. In all cases, the implantation of anterior capsule-fixated IOLs was possible. No complications occurred during surgery or within the first months after surgery. With the described technique, capsulefixated IOLs can be implanted in eyes with small pupil easily and safely. This type of IOL has great potential to improve the refractive outcome by better prediction of the postoperative IOL position and eliminating IOL rotation after cataract surgery. [J Refract Surg. 2017;33(8):568-570.]. Copyright 2017, SLACK Incorporated.

  16. Influence of a new surface modification of intraocular lenses with fluoroalkylsilan on the adherence of endophthalmitis-causing bacteria in vitro.

    Science.gov (United States)

    Kienast, Antonia; Kämmerer, Regine; Weiss, Claudia; Klinger, Matthias; Menz, Dirk-Henning; Dresp, Joachim; Ohgke, Helge; Solbach, Werner; Laqua, Horst; Hoerauf, Hans

    2006-09-01

    Dynasilan is a fluoroalkylsilan that is able to interact with surface active centres on intraocular lenses (IOL), offering a new way for surface modification of different IOL materials. The purpose of this in vitro study was to investigate the influence of this new surface modification on the adherence of two typical endophthalmitis causing bacteria (Staphylococcus epidermidis, Propionibacterium acnes). In a pilot experiment, the effect of Dynasilan coating on the adherence of S. epidermidis was tested on glass slides. Forty-two Dynasilan-modified and 42 unmodified IOL (14 PMMA, 14 silicone and 14 hydrogel) were incubated at 37 degrees C in brain heart infusion broth (10(8) CFU/ml) with either S. epidermidis for 24 h or with P. acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3x45 s. After dilution series and incubation at 37 degrees C on Petri dishes for 24 h and 3 days, respectively, the colonies were counted. In the pilot experiment, a markedly lower number of adherent S. epidermidis was observed on Dynasilan-modified glass slides. Of all IOL materials incubated with S. epidermidis, those modified with Dynasilan showed a lower mean number of adherent bacteria (mean 1.37x10(7); SD 2.37x10(7)) than those untreated (2.43x10(7); SD 3.04x10(7)). IOLs incubated with P. acnes showed a significantly lower mean number of adherent bacteria of 2.51x10(4) (SD 2.71x10(4)) on Dynasilan-modified IOLs versus 6.27x10(4) (SD 7.70x10(4)) on untreated IOLs. The presented in vitro results indicate that Dynasilan surface modification is able to reduce the adherence of S. epidermidis and P. acnes on all IOL materials tested. Further studies regarding the stability of this modification and its biocompatibility must be performed.

  17. Ocular surface displacement with and without contact lenses during non-contact tonometry.

    Science.gov (United States)

    Rimayanti, Ulfah; Kiuchi, Yoshiaki; Uemura, Shohei; Takenaka, Joji; Mochizuki, Hideki; Kaneko, Makoto

    2014-01-01

    To evaluate the displacement of the central ocular surface during non-contact tonometry with and without soft contact lenses and determine the factors associated with the displacement of the central ocular surface and intraocular pressure (IOP) reading changes caused by wearing soft contact lenses (CLs). One eye each in 21 subjects was studied. The cornea was photographed using a high-speed camera at 5,000 frames/sec during non-contact tonometry without contact lenses (NCL), with -5.0 diopters (D), -0.5 D and +5.0 D CL. The displacement of the ocular surface and the factors affecting displacement at the IOP reading and maximum displacement time were investigated. The IOP readings while wearing +5 D CL were significantly higher than those obtained while wearing -5 D CL. The ocular surface displacement between +5 D CL and other groups were significantly different. A significant positive correlation was found between the ocular surface displacement of subjects at the IOP reading time and the IOP obtained with the non-contact tonometer. A significant negative correlation was found between the ocular surface curvature and the IOP obtained using the non-contact tonometer. The radius of curvature of the ocular surface affected the displacement during the IOP reading and maximum displacement time. Our results indicate that soft contact lens use changes the ocular surface behavior and IOP readings during non-contact tonometry. The radius of curvature of the eye affects the ocular surface displacement and IOP readings in this situation.

  18. Dermal oncogenicity bioassays of monofunctional and multifunctional acrylates and acrylate-based oligomers.

    Science.gov (United States)

    DePass, L R; Maronpot, R R; Weil, C S

    1985-01-01

    Several important components of photocurable coatings were studied for dermal tumorigenic activity by repeated application to the skin of mice. The substances tested were 2-ethylhexyl acrylate (EHA) and methylcarbamoyloxyethyl acrylate (MCEA) (monomers); neopentyl glycol diacrylate (NPGDA), esterdiol-204-diacrylate (EDDA), and pentaerythritol tri(tetra)acrylate (PETA) (cross-linkers); and three acrylated urethane oligomers. For each bioassay, 40 C3H/HeJ male mice were dosed 3 times weekly on the dorsal skin for their lifetime with the highest dose of the test agent that caused no local irritation or reduction in body weight gain. Two negative control groups received acetone (diluent) only. A positive control group received 0.2% methylcholanthrene (MC). NPGDA and EHA had significant tumorigenic activity with tumor yields of eight and six tumor-bearing mice (three and two malignancies), respectively. The MC group had 34 mice with carcinomas and 1 additional mouse with a papilloma. MCEA had no dermal tumorigenic activity but resulted in early mortality. No skin tumors in the treatment area were observed in the other groups. Additional studies will be necessary to elucidate possible relationships between structure and tumorigenic activity for the acrylates.

  19. INTRAOCULAR LENS POSITION IN COMBINED PHACOEMULSIFICATION AND VITREORETINAL SURGERY.

    Science.gov (United States)

    Ozates, Serdar; Kiziltoprak, Hasan; Koc, Mustafa; Uzel, Mehmet Murat; Teke, Mehmet Yasin

    2017-10-09

    To assess the decentration and angle of tilt of the intraocular lens (IOL) according to the intravitreal tamponade types used in combined phacoemulsification and vitreoretinal surgery. This prospective and randomized clinical study involved 73 eyes of 69 patients who underwent combined vitreoretinal surgery. Eyes with intravitreal tamponades formed the study group and eyes without intravitreal tamponades formed the control group. The study group was further divided into silicone oil and gas tamponade subgroups. Cross-sectional IOL images were captured using a Pentacam HR (Oculus, Germany) and tilt and decentration were calculated with Adobe Photoshop software (Adobe, San Jose, CA). The mean angle of tilt and decentration at the vertical meridian were significantly higher in both tamponade groups than in the control group (P 0.05). When comparing the silicone oil and gas tamponade subgroups, no significant differences were noted on the position of IOL at both meridians (P > 0.05 for all). Intravitreal tamponades have an important effect on the position of IOL in combined vitreoretinal surgery. Silicone oil and gas tamponades may induce postoperative tilt and decentration of one-piece acrylic IOLs.

  20. Acrylic vessel cleaning tests

    International Nuclear Information System (INIS)

    Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

    1997-01-01

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  1. Optical ensemble analysis of intraocular lens performance through a simulated clinical trial with ZEMAX.

    Science.gov (United States)

    Zhao, Huawei

    2009-01-01

    A ZEMAX model was constructed to simulate a clinical trial of intraocular lenses (IOLs) based on a clinically oriented Monte Carlo ensemble analysis using postoperative ocular parameters. The purpose of this model is to test the feasibility of streamlining and optimizing both the design process and the clinical testing of IOLs. This optical ensemble analysis (OEA) is also validated. Simulated pseudophakic eyes were generated by using the tolerancing and programming features of ZEMAX optical design software. OEA methodology was verified by demonstrating that the results of clinical performance simulations were consistent with previously published clinical performance data using the same types of IOLs. From these results we conclude that the OEA method can objectively simulate the potential clinical trial performance of IOLs.

  2. Potential contact and intraocular lenses based on hydrophilic/hydrophobic sulfonated syndiotactic polystyrene membranes

    Directory of Open Access Journals (Sweden)

    Simona Zuppolini

    2017-10-01

    Full Text Available Crystalline films of syndiotactic polystyrene (s-PS, a commercially available thermoplastic polymer, having a highly hydrophilic amorphous phase, were achieved by using a mild solid-state sulfonation procedure. Despite the used mild process conditions, an easy and uniform sulfonation of the phenyl rings of the amorphous phase is obtained. The crystallinity of the polymer was not affect by the sulfonation degree (S, at least at S less than 20%, and the obtained polymer films show the nanoporous crystalline form of s-PS. As widely reported in literature, the nanoporous nature of the polymer crystalline phase gives to these materials the ability to absorb and release organic molecules of appropriate size and polarity. This property, coupled to transparency, makes these materials potentially useful intraocular lens (IOLs and contact lens applications. Sulfonation procedure and sulfonated film samples characterization by using wide-angle X-ray diffraction (WAXD, Fourier-transform infrared (FTIR and ultraviolet-visible (UV-vis spectroscopy techniques and water sorption tests were reported. Furthermore, the biocompatibility study demonstrated no cytotoxicity and appropriate cell interaction properties for the specific applications.

  3. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    LENUS (Irish Health Repository)

    Nagle, Susan

    2009-09-01

    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.

  4. Neodymium:YAG laser cutting of intraocular lens haptics in vitro and in vivo.

    Science.gov (United States)

    Feder, J M; Rosenberg, M A; Farber, M D

    1989-09-01

    Various complications following intraocular lens (IOL) surgery result in explantation of the lenses. Haptic fibrosis may necessitate cutting the IOL haptics prior to removal. In this study we used the neodymium: YAG (Nd:YAG) laser to cut polypropylene and poly(methyl methacrylate) (PMMA) haptics in vitro and in rabbit eyes. In vitro we were able to cut 100% of both haptic types successfully (28 PMMA and 30 polypropylene haptics). In rabbit eyes we were able to cut 50% of the PMMA haptics and 43% of the polypropylene haptics. Poly(methyl methacrylate) haptics were easier to cut in vitro and in vivo than polypropylene haptics, requiring fewer shots for transection. Complications of Nd:YAG laser use frequently interfered with haptic transections in rabbit eyes. Haptic transection may be more easily accomplished in human eyes.

  5. Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

    International Nuclear Information System (INIS)

    Saliza Jam; Mansor Ahmad; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan

    2001-01-01

    Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

  6. Intraocular lymphoma

    Directory of Open Access Journals (Sweden)

    Li-Juan Tang

    2017-08-01

    Full Text Available Intraocular lymphoma (IOL is a rare lymphocytic malignancy which contains two main distinct forms. Primary intraocular lymphoma (PIOL is mainly a sub-type of primary central nervous system lymphoma (PCNSL. Alternatively, IOL can originate from outside the central nervous system (CNS by metastasizing to the eye. These tumors are known as secondary intraocular lymphoma (SIOL. The IOL can arise in the retina, uvea, vitreous, Bruch’s membrane and optic nerve. There are predominantly of B-cell origin; however there are also rare T-cell variants. Diagnosis remains challenging for ophthalmologists and pathologists, due to its ability to masquerade as noninfectious or infectious uveitis, white dot syndromes, or occasionally as other metastatic cancers. Laboratory tests include flow cytometry, immunocytochemistry, interleukin detection (IL-10: IL-6, ratio >1, and polymerase chain reaction (PCR amplification. Methotrexate-based systemic chemotherapy with external beam radiotherapy and intravitreal chemotherapy with methotrexate are useful for controlling the disease, but the prognosis remains poor. Therefore, it is important to make an early diagnose and treatment. This review is focused on the clinical manifestations, diagnosis, treatment and prognosis of the IOL.

  7. Synthesis of Poly(styrene-acrylates-acrylic acid Microspheres and Their Chemical Composition towards Colloidal Crystal Films

    Directory of Open Access Journals (Sweden)

    Luis A. Ríos-Osuna

    2016-01-01

    Full Text Available In this paper, polystyrene colloidal microspheres have been prepared using hexyl acrylate (HA, ethylhexyl acrylate (EHA, isooctyl acrylate (IOA, butyl acrylate (BA, or isobutyl acrylate (IBA as comonomers. Microspheres with diameters from 212 to 332 nm and with a polystyrene content of 65–78% were prepared. The particles prepared in this work do not present the typical core-shell structure; as a consequence, DSC analysis showed that the microspheres exhibited only one Tg. TEM images show that the particles with comonomer content below ~30% were spherical and regular. Microspheres containing comonomer between 21 to 25% produced the less brittle films showing very iridescent colors. The films prepared from microspheres containing hexyl, ethylhexyl, and isooctyl acrylate as comonomers are firmly attached to the substrate due to their adhesive properties. The large decrease of the fragility observed in these films makes them much more attractive materials in sensing applications.

  8. Interactions of Bacteria and Amoebae with Ocular Biomaterials

    OpenAIRE

    John, Thomas

    1991-01-01

    The use of biomaterials in periocular and intraocular sites has resulted in some ocular inflammations and infections which can result in vision-threatening ocular disease. This review addresses bacterial interactions with, and adherence to ocular biomaterials such as soft contact lenses, surgical suture materials, and intraocular lenses. In addition, adherence of Acanthamoeba to soft contact lenses is described, and the role of these lenses in the development of Acanthamoeba keratitis is disc...

  9. Black diaphragm intraocular lens implantation and penetrating keratoplasty in aphakic eyes with traumatic aniridia

    Directory of Open Access Journals (Sweden)

    Xiao-Guang Dong

    2013-04-01

    Full Text Available AIM: To evaluate the long-term outcome of implantation of black diaphragm intraocular (BDI lens combined with penetrating keratoplasty (PKP for managing aphakic eyes with traumatic aniridia and corneal damage. METHODS: Six aphakic eyes of six patients with traumatic aniridia and corneal damage had BDI lens implantation at Qingdao Eye Hospital, Shandong Eye Institute from June 2008 to November 2011. Medical records of the patients were reviewed. Three patients received PKP and after 12-18months were implanted with BDI lens. The other three patients completed PKP and BDI lens implantation at the same time. The corrected visual acuity, intraocular pressure and number of corneal endothelial cells were monitored. RESULTS: The patients were followed up for an average of 24.3±12.1months (range 14-48 months. All BDI lenses were located well. The best corrected visual acuity got improved in 5 patients (0.1-1.0 and decreased in 1 patient from 0.4 to 0.2. Three patients had normal intraocular pressure (IOP after implantation. Two patients required antiglaucoma medications to control IOP within the normal range and 1 patient implanted Ahmed glaucoma valve to control IOP. The corneal grafts kept transparent in all eyes and the corneal endothelial counting >1 000/mm2, although two patients experienced acute graft rejection and loss more than 30% corneal endothelial cells. CONCLUSION: Implantation of BDI lens combined with PKP is an effective option for managing aphakic eyes with traumatic aniridia and corneal damage. Although the results in our study are encouraging, additional studies of the long-term safety and efficacy are required. A larger study population and longer follow-up may be beneficial.

  10. Ocular surface displacement with and without contact lenses during non-contact tonometry.

    Directory of Open Access Journals (Sweden)

    Ulfah Rimayanti

    Full Text Available PURPOSE: To evaluate the displacement of the central ocular surface during non-contact tonometry with and without soft contact lenses and determine the factors associated with the displacement of the central ocular surface and intraocular pressure (IOP reading changes caused by wearing soft contact lenses (CLs. METHODS: One eye each in 21 subjects was studied. The cornea was photographed using a high-speed camera at 5,000 frames/sec during non-contact tonometry without contact lenses (NCL, with -5.0 diopters (D, -0.5 D and +5.0 D CL. The displacement of the ocular surface and the factors affecting displacement at the IOP reading and maximum displacement time were investigated. RESULTS: The IOP readings while wearing +5 D CL were significantly higher than those obtained while wearing -5 D CL. The ocular surface displacement between +5 D CL and other groups were significantly different. A significant positive correlation was found between the ocular surface displacement of subjects at the IOP reading time and the IOP obtained with the non-contact tonometer. A significant negative correlation was found between the ocular surface curvature and the IOP obtained using the non-contact tonometer. The radius of curvature of the ocular surface affected the displacement during the IOP reading and maximum displacement time. CONCLUSIONS: Our results indicate that soft contact lens use changes the ocular surface behavior and IOP readings during non-contact tonometry. The radius of curvature of the eye affects the ocular surface displacement and IOP readings in this situation.

  11. Accommodative intraocular lens versus standard monofocal intraocular lens implantation in cataract surgery.

    Science.gov (United States)

    Ong, Hon Shing; Evans, Jennifer R; Allan, Bruce D S

    2014-05-01

    Following cataract surgery and intraocular lens (IOL) implantation, loss of accommodation or postoperative presbyopia occurs and remains a challenge. Standard monofocal IOLs correct only distance vision; patients require spectacles for near vision. Accommodative IOLs have been designed to overcome loss of accommodation after cataract surgery. To define (a) the extent to which accommodative IOLs improve unaided near visual function, in comparison with monofocal IOLs; (b) the extent of compromise to unaided distance visual acuity; c) whether a higher rate of additional complications is associated the use of accommodative IOLs. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 9), Ovid MEDLINE, Ovid MEDLINE in-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily Update, Ovid OLDMEDLINE (January 1946 to October 2013), EMBASE (January 1980 to October 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 October 2013. We include randomised controlled trials (RCTs) which compared implantation of accommodative IOLs to implantation of monofocal IOLs in cataract surgery. Two authors independently screened search results, assessed risk of bias and extracted data. All included trials used the 1CU accommodative IOL (HumanOptics, Erlangen, Germany) for their intervention group. One trial had an additional arm with the AT-45 Crystalens accommodative IOL (Eyeonics Vision). We performed a separate analysis comparing 1CU and AT-45 IOL. We included four RCTs, including 229 participants (256 eyes

  12. Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren

    2014-01-01

    Two new polymer grafts on an industrial grade multiwalled carbon nanotube (MWCNT) were prepared through a non-oxidative pathway employing controlled free radical polymerization for surface initiated polymer grafting. After photochemical introduction of an ATRP initiator onto the MWCNT......, polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... in loading after 12 h of polymerization. The modified nanomaterials were melt mixed into polypropylene composites with very low filler loading (0.3 wt%), whereafter both the thermal and electrical properties were investigated by DSC and dielectric resonance spectroscopy. The electrical properties were found...

  13. 40 CFR 721.405 - Polyether acrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether acrylate. 721.405 Section... § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyether acrylate (PMN P-95-666) is subject to...

  14. Resultados del implante múltiple de lentes intraoculares en la cirugía de catarata en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" Results of the multiple intraocular lenses implantation in the cataract surgery performed at "Ramón Pando Ferrer" Cuban Institute of Ophthalmology

    Directory of Open Access Journals (Sweden)

    Eric Montero Díaz

    2010-06-01

    Full Text Available OBJETIVO: Valorar los resultados visuales de los pacientes operados con la técnica de piggy back o implantes múltiples de lentes intraoculares. MÉTODOS: Se realizó un estudio descriptivo retrospectivo de corte transversal en el que se tomaron 32 ojos de 30 pacientes del universo operado de catarata, con la técnica antes descrita, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer", en el período comprendido entre enero de 2000 hasta diciembre de 2006. Fueron evaluadas algunas variables demográficas, como edad y sexo, así como agudeza visual y refracción preoperatorio y posoperatoria con cristales y sin ellos. Reportamos las complicaciones transquirúrgicas y posquirúrgicas asociadas a las diferentes técnicas quirúrgicas empleadas para la extracción del cristalino. RESULTADOS: La edad promedio obtenida fue mayor de 50 años, y predominó el sexo femenino. Parte de los pacientes tuvieron una agudeza visual corregida superior a 20/40. La complicación más frecuente fue la opacidad de la cápsula posterior y solo en la tercera parte de los pacientes se obtuvo una buena corrección refractiva. CONCLUSIONES: La técnica de piggy back permitió la recuperación de cuatro líneas en la cartilla de Snellen en la agudeza visual corregida, mientras que en la agudeza visual sin corrección solo aumentó en dos líneas. Se encontró igual número de pacientes hipocorregidos y bien corregidos.OBJECTIVE: To asses the visual results of patients operated on by piggy back technique or multiple implantation of intraocular lenses METHODS: A retrospective cross-sectional descriptive study was conducted in 32 eyes from 30 patients operated on from cataract, using the above-mentioned technique, at "Ramon Pando Ferrer" Cuban Institute of Ophthalmology in the period January 2000 through December 2006. Some demographic variables as age and sex as well as visual acuity and preoperative and postoperative refraction with/without lenses were evaluated

  15. Gravitationally Lensed Quasars in Gaia: II. Discovery of 24 Lensed Quasars

    Science.gov (United States)

    Lemon, Cameron A.; Auger, Matthew W.; McMahon, Richard G.; Ostrovski, Fernanda

    2018-04-01

    We report the discovery, spectroscopic confirmation and preliminary characterisation of 24 gravitationally lensed quasars identified using Gaia observations. Candidates were selected in the Pan-STARRS footprint with quasar-like WISE colours or as photometric quasars from SDSS, requiring either multiple detections in Gaia or a single Gaia detection near a morphological galaxy. The Pan-STARRS grizY images were modelled for the most promising candidates and 60 candidate systems were followed up with the William Herschel Telescope. 13 of the lenses were discovered as Gaia multiples and 10 as single Gaia detections near galaxies. We also discover 1 lens identified through a quasar emission line in an SDSS galaxy spectrum. The lenses have median image separation 2.13″ and the source redshifts range from 1.06 to 3.36. 4 systems are quadruply-imaged and 20 are doubly-imaged. Deep CFHT data reveal an Einstein ring in one double system. We also report 12 quasar pairs, 10 of which have components at the same redshift and require further follow-up to rule out the lensing hypothesis. We compare the properties of these lenses and other known lenses recovered by our search method to a complete sample of simulated lenses to show the lenses we are missing are mainly those with small separations and higher source redshifts. The initial Gaia data release only catalogues all images of ˜ 30% of known bright lensed quasars, however the improved completeness of Gaia data release 2 will help find all bright lensed quasars on the sky.

  16. Pigment dispersion glaucoma induced by the chafing effect of intraocular lens haptics in Asian eyes.

    Science.gov (United States)

    Hong, Ying; Sun, Yan-Xiu; Qi, Hong; Zhou, Ji-Chao; Hao, Yan-Sheng

    2013-03-01

    To study the possible mechanism and treatment for pigment dispersion glaucoma (PDG) caused by single-piece acrylic (SPA) intraocular lens (IOL) ciliary sulcus fixation in Asian eyes. Patients referred for PDG caused by SPA IOL ciliary sulcus fixation to our hospital from April 2005 to June 2011 were included. The patients' general information, IOL type, interval between initial surgery and PDG occurrence, examination findings, antiglaucoma medicine regimen and surgical interventions were recorded. In total, six eyes from five Chinese patients were included in this study. The intraocular pressure (IOP) increased 19-30 days after cataract surgery and was not satisfactorily controlled with antiglaucoma medication. Dense pigmentation was deposited on the IOLs and on the anterior chamber angle. IOL haptic chafing was noted on the rear iris surface. IOL repositioning in the capsular bag was performed in three eyes and was combined with trabeculectomy in two eyes with progressive glaucoma. An IOL exchange with three-piece IOL ciliary sulcus fixation was performed in the other three eyes. Scanning electron microscopy of the explanted IOLs demonstrated a rough edge on the IOL haptics. SPA IOLs were not suitable for ciliary sulcus fixation. The chafing effect of the IOL haptics on the posterior iris pigment epithelium could induce PDG in Asian eyes. IOLs should be positioned in the capsular bag or a three-piece IOL should be used instead.

  17. Comparison between OPD-Scan results and visual outcomes of monofocal and multifocal intraocular lenses Comparação dos resultados do OPD-Scan e performance visual das lentes intraoculares monofocal e multifocal

    Directory of Open Access Journals (Sweden)

    Wilson Takashi Hida

    2009-08-01

    Full Text Available PURPOSE: To compare the visual outcome, contrast sensitivity and wavefront analysis of patients that underwent cataract surgery and implantation of AcrySof SN60D3 multifocal intraocular lens with those who received the AcrySof SN60AT monofocal IOL. METHODS: This was a prospective clinical trial of forty eyes that received the multifocal IOL and thirty-two eyes that received the monofocal IOL after phacoemulsification. RESULTS: Values for total and spherical aberrations in the multifocal group were statistically lower than in the monofocal group. In the monofocal group, 75% achieved uncorrected intermediate visual acuities between Jaeger 1 and 6. In the multifocal group, 75% of the eyes achieved more than Jaeger 6. At least 87.5% of the multifocal group and 6.3% of the monofocal group achieved monocular uncorrected near acuity of 20/30 (J2, N5 or better. And 90.0% of the eyes in the multifocal group and 37.5% in the monofocal group achieved an uncorrected near acuity of 20/40 (J3, N6 or better. The mean spherical error was 0.11 D in the multifocal group and -0.18 D in the monofocal group (p=0.0379. The SN60D3 group compared to SN60AT group had low contrast sensitivity (log units with statistically significant differences in 6.0 cpd in photopic conditions (p=0.014 and the SN60D3 group compared to SN60AT group had higher contrast sensitivity (log units under mesopic conditions (p=0.044. CONCLUSION: The multifocal IOLs induced less spherical aberration than monofocal IOLs and predictably good uncorrected distance and uncorrected near acuities. However, contrast sensitivity was lower in the multifocal group.OBJETIVO: Comparar a performance visual, sensibilidade ao contraste e de wavefront com OPD-Scan em pacientes submetidos a cirurgia de facoemulsificação com implante de lente intraocular AcrySof SN60D3 multifocal e AcrySof SA60AT monofocal. MÉTODOS: Quarenta olhos com a lente intraocular multifocal e trinta e dois olhos com a lente intraocular

  18. 40 CFR 721.8082 - Polyester polyurethane acrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane acrylate...

  19. Assessment of the safety and efficacy of primary retropupillary fixation of iris-claw intraocular lenses in children with large lens subluxations.

    Science.gov (United States)

    Rastogi, Anju; Goray, Apurva; Thacker, Prolima; Kamlesh; Babita

    2017-08-17

    To evaluate whether retropupillary fixation of the iris-claw intraocular lens (IOL) is a safe and effective treatment option in children with large lens subluxations. Fourteen eyes of children between the ages of 8-17 years with lens subluxations more than 7 clock hours underwent pars plana lensectomy-vitrectomy with implantation of the iris-claw IOL in the retropupillary position as a primary procedure. The best corrected visual acuity (BCVA), intraocular pressure (IOP), corneal endothelial count (EC) and the lens position using ultrasound biomicroscopy (UBM) were assessed pre- and postoperatively. Postoperatively, all patients had an increase in the BCVA with a mean of 0.351 ± 0.154 log MAR units which was statistically significant as compared to the preoperative value of 0.771 ± 0.132 log MAR units (p = 0.003). The difference between the mean preoperative IOP (13.642 ± 2.437 mmHg) and the mean postoperative intraocular pressure at the end of 6 months (13.5 ± 2.244 mmHg) was not statistically significant (p = 0.671). The mean EC decreased by 0.99% from 2838.42 ± 474.76 cells/mm 2 preoperatively to 2810 ± 461.24 cells/mm 2 at the end of 6 months postoperatively (p = 0.117). The lens position was analyzed using UBM and was found to be parallel to the iris plane in all cases at the end of 6 months. Our study shows that primary retropupillary iris-claw IOL implantation can be a safe and efficacious option for children with large (>7 clock hours) lens subluxations that is at least comparable to scleral-fixated PCIOLs.

  20. Acuidade visual em implantes bilaterais de lentes intra-oculares monofocais e multifocais Visual acuity of bilateral implants of monofocal and multifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Leonardo Akaishi

    2003-01-01

    Full Text Available OBJETIVO: Comparar a acuidade visual de longe e perto de pacientes submetidos à facoemulsificação binocular não simultânea com implante de lentes multifocais ou monofocais. MÉTODOS: Foram selecionados 20 pacientes com lentes multifocais bilaterais e outros 20 pacientes com lentes monofocais também bilaterais, com acuidade visual sem correção melhor ou igual a 0,63 (20/30, medidos separadamente, nos três primeiros meses de pós-operatório. Foi medida a acuidade visual para longe e perto com e sem correção e testes de sensibilidade ao contraste e ofuscamento. RESULTADOS: A acuidade visual sem correção para longe no grupo das monofocais teve média de 0,82 (DP± 0,16 e no grupo das multifocais, 0,94 (DP±0,12, valor de p 0,001. Os dois grupos de lentes tiveram visão com correção para longe igual a 1. No grupo das multifocais, 75% tiveram J1 e 100% tiveram J3 ou melhor sem correção. No grupo das lentes monofocais, 10% tiveram J1 e 70% tiveram J3 ou melhor sem correção. Não houve diferença significante na avaliação com o teste de sensibilidade ao contraste entre os grupos pesquisados. No teste de ofuscamento, os dois grupos tiveram redução da visão, que foi mais acentuada no grupo dos pacientes com lentes multifocais. CONCLUSÃO: A acuidade visual para longe com correção nos pacientes com implante multifocal foi semelhante a dos pacientes com implantes monofocais, embora a acuidade visual para perto no grupo em que foi implantado lente multifocal foi bastante superior ao grupo da lente monofocal. A sensibilidade ao contraste manteve-se semelhante nos dois grupos, já o ofuscamento ("glare test" no grupo multifocal foi maior que no grupo monofocal.PURPOSE: To compare distant and near visual acuity between patients submitted to bilateral nonsimultaneous facoemulsification and implantation of multifocal or monofocal intraocular lenses (IOL. METHODS: Twenty patients with bilateral multifocal IOL and 20 patients with

  1. Ultrasonic velocities, densities, and excess molar volumes of binary mixtures of N,N-dimethyl formamide with methyl acrylate, or ethyl acrylate, or butyl acrylate, or 2-ethyl hexyl acrylate at T = 308.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Kondaiah, M. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Sravana Kumar, D. [Dr. V.S. Krishna Govt. Degree College, Visakhapatnam, Andhra Pradesh (India); Sreekanth, K. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Krishna Rao, D., E-mail: krdhanekula@yahoo.co.in [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India)

    2011-12-15

    Highlights: > Positive values of V{sub m}{sup E}, indicate dispersion forces between acrylic esters and DMF. > V{sub m}{sup E} values compared with Redlich-Kister polynomial. > Partial molar volumes data conclude that weak interactions exist in the systems. > Measured velocity values compared with theoretical values obtained by polynomials. - Abstract: Ultrasonic velocities, u, densities, {rho}, of binary mixtures of N,N-dimethyl formamide (DMF) with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), and 2-ethyl hexyl acrylate (EHA), including pure liquids, over the entire composition range have been measured at T = 308.15 K. Using the experimental results, the excess molar volume, V{sub m}{sup E}, partial molar volumes, V-bar {sub m,1}, V-bar{sub m,2}, and excess partial molar volumes, V-bar{sub m,1}{sup E}, V-bar{sub m,2}{sup E} have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess values of calculated properties. The excess properties have been fitted to Redlich-Kister type polynomial and the corresponding standard deviations have been calculated. The positive values of V{sub m}{sup E} indicate the presence of dispersion forces between the DMF and acrylic ester molecules. Further theoretical values of sound velocity in the mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the systems studied. Theoretical ultrasonic velocity data have been used to study molecular interactions in the binary systems investigated.

  2. Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

    Science.gov (United States)

    Lones, Joe J.; Stachiw, Jerry D.

    1983-10-01

    Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

  3. Intraocular inflammation in autoimmune diseases.

    Science.gov (United States)

    Pras, Eran; Neumann, Ron; Zandman-Goddard, Gisele; Levy, Yair; Assia, Ehud I; Shoenfeld, Yehuda; Langevitz, Pnina

    2004-12-01

    The uveal tract represents the vascular organ of the eye. In addition to providing most of the blood supply to the intraocular structures, it acts as a conduit for immune cells, particularly lymphocytes, to enter the eye. Consequently, the uveal tract is represented in many intraocular inflammatory processes. Uveitis is probably a misnomer unless antigens within the uvea are the direct targets of the inflammatory process. A better term of the condition is "intraocular inflammation" (IOI). To review the presence of IOI in autoimmune diseases, the immunopathogenic mechanisms leading to disease, and treatment. We reviewed the English medical literature by using MEDLINE (1984-2003) employing the terms "uveitis," "intraocular inflammation," and "autoimmune diseases." An underlying autoimmune disease was identified in up to 40% of patients with IOI, and included spondyloarthropathies, Behcets disease, sarcoidosis, juvenile chronic arthritis, Vogt-Koyanagi-Harada syndrome (an inflammatory syndrome including uveitis with dermatologic and neurologic manifestations), immune recovery syndrome, and uveitis with tubulointerstitial disease. The immunopathogenesis of IOI involves enhanced T-cell response. Recently, guidelines for the use of immunosuppressive drugs for inflammatory eye disease were established and include: corticosteroids, azathioprine, methotrexate, mycophenolate mofetil, cyclosporine, tacrolimus, cyclophosphamide, and chlorambucil. New therapies with limited experience include the tumor necrosis factor alpha inhibitors, interferon alfa, monoclonal antibodies against lymphocyte surface antigens, intravenous immunoglobulin (IVIG), and the intraocular delivery of immunosuppressive agents. An underlying autoimmune disease was identified in up to 40% of patients with IOI. Immunosuppressive drugs, biologic agents, and IVIG are employed for the treatment of IOI in autoimmune diseases.

  4. Reading ability with pseudophakic monovision and with refractive multifocal intraocular lenses: comparative study.

    Science.gov (United States)

    Ito, Misae; Shimizu, Kimiya

    2009-09-01

    To the compare the reading ability after bilateral cataract surgery in patients who had pseudophakic monovision achieved by monofocal intraocular lens (IOL) implantation and patients who had refractive multifocal IOL implantation. Department of Ophthalmology, Kitasato University Hospital, Kanagawa, Japan. This study evaluated patients who had bilateral cataract surgery using the monovision method with monofocal IOL implantation to correct presbyopia (monovision group) or who had bilateral cataract surgery with refractive multifocal IOL implantation (multifocal group). In the monovision group, the dominant eye was corrected for distance vision and the nondominant eye for near vision. The maximum reading speed, critical character size, and reading acuity were measured binocularly without refractive correction using MNREAD-J acuity charts. The monovision group comprised 38 patients and the multifocal group, 22 patients. The mean maximum reading speed was 350.5 characters per minute (cpm) +/- 62.3 (SD) in the monovision group and 355.0 +/- 53.3 cpm in the multifocal group; the difference was not statistically significant. The mean critical character size was 0.24 +/- 0.12 logMAR and 0.40 +/- 0.16 logMAR, respectively (P<.05). The mean reading acuity was 0.05 +/- 0.12 logMAR and 0.19 +/- 0.11 logMAR, respectively (P<.01). The monovision group had better critical character size and reading acuity results. The monovision method group had better reading ability; however, careful patient selection is essential.

  5. Subjective evaluation of uncorrected vision in patients undergoing cataract surgery with (diffractive multifocal lenses and monovision

    Directory of Open Access Journals (Sweden)

    Stock RA

    2017-07-01

    Full Text Available Ricardo Alexandre Stock, Thaís Thumé, Luan Gabriel Paese, Elcio Luiz Bonamigo Universidade do Oeste de Santa Catarina, Rua Getúlio Vargas, Joaçaba, Santa Catarina, Brazil Purpose: To analyze patient satisfaction and difficulties with bilateral multifocal intraocular lenses (IOLs implantation and aspheric monofocal IOLs implantation using monovision, after cataract surgery.Materials and methods: A total of 61 participants were included in the study, 29 with monovision and 32 with multifocal lenses. The inclusion criteria were patients undergoing phacoemulsification for bilateral visual impairment due to cataracts and presenting with postoperative visual acuity of 20/30 or better for distance and line J3 or better for near vision.Results: The 2 groups had similar results regarding difficulties with daily activities such as distance vision, near vision, watching television, reading, cooking, using a computer or cellphone, shaving/putting on makeup and shopping. There were differences in responses between the groups regarding difficulty with night vision (P=0.0565 and night driving (P=0.0291. Degree of satisfaction in terms of distance vision without glasses was statistically significantly better in monovision group (P=0.0332, but not for near (P=0.9101.Conclusion: Both techniques yielded satisfactory results regarding visual acuity for different activities without the need to use glasses. Multifocal lenses are a good option for patients with the exception of night driving, and who desire independence from glasses. Keywords: cataract extraction, aphakia, postcataract, patient satisfaction, night vision

  6. Dynamically formed hydrous zirconium (IV) oxide-polyelectrolyte membranes. III: Poly(acrylic acid) and substituted poly(acrylic acid) homo, co and terpolymer membranes

    International Nuclear Information System (INIS)

    Van Reenen, A.J.; Sanderson, R.D.

    1989-01-01

    A series of acrylic acid and substituted acrylic acid homo, co and terpolymers was synthesised. These polymers were used as polyelectrolytes in dynamically formed hydrous zirconium (iv) oxide-polyelectrolyte membranes. Substitution of the acrylic acid α-hydrogen was done to increase the number of carboxylic acid groups per monomer unit and to change the acid strength of acrylic acid carboxylic acid group. None of these changes improved the salt rejection of these membranes over that of commercially used poly(acrylic acid). Improvement in rejection was found when a hydrophobic comonomer, vinyl acetate, was used in conjunction with acrylic acid in a copolymer dynamic membrane. 16 refs., 6 figs., 1 tab

  7. Comparison between bilateral implantation of a trifocal intraocular lens and blended implantation of two bifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Vilar C

    2017-08-01

    Full Text Available César Vilar,1,2 Wilson Takashi Hida,1–3 André Lins de Medeiros,1,2 Klayny Rafaella Pereira Magalhães,2 Patrick Frensel de Moraes Tzelikis,1,2 Mario Augusto Pereira Dias Chaves,2,4 Antônio Francisco Pimenta Motta,2,3 Pedro Carlos Carricondo,1–3 Milton Ruiz Alves,3 Walton Nosé5 1Cataract Division, Brasília Ophthalmologic Hospital (HOB, Brasília-DF, Brazil; 2Renato Ambrosio Ophthalmologic Research Center (CEORA, 3Ophthalmology Department, São Paulo University – USP, São Paulo-SP, Brazil; 4Cataract Division, ProVisão, João Pessoa-PB, Brazil; 5Ophthalmology Department, Paulista Medical School – UNIFESP, São Paulo-SP, Brazil Purpose: To compare visual outcomes and performance between bilateral implantation of a diffractive trifocal intraocular lens (IOL Acrysof®PanOptix® TFNT00 and blended implantation of two different near add power bifocal IOLs: Acrysof® Restor® SV25T0 in dominant eye and Acrysof® Restor® SN6AD1 in the nondominant eye.Methods: This prospective, nonrandomized, consecutive and comparative study assessed 20 patients (40 eyes who had bilateral cataract surgery performed using the IOLs described. Patients were divided into groups, bilateral trifocal implant and blended implant. Evaluation included measurement of binocular uncorrected and corrected distance visual acuity at 4 m (UDVA, CDVA and uncorrected intermediate (60 cm and near (at 40 cm visual acuity; contrast sensitivity (CS and visual defocus curve.Results: Postoperative CDVA comparison showed no statistical significance between groups. UDVA was significantly better in the trifocal groups. Under photopic conditions, the trifocal group had better CS in higher frequencies with and without glare. The binocular defocus curve demonstrated a trifocal behavior in both groups, with the bilateral trifocal group exhibiting better performance for intermediate vision.Conclusion: Both lens combinations were able to provide good near, intermediate and distance vision

  8. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  9. 21 CFR 886.3600 - Intraocular lens.

    Science.gov (United States)

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials such as glass or plastic intended to be implanted to replace the natural lens of an eye. (b) Classification. Class III. (c) Date PMA or notice of completion of a...

  10. 21 CFR 886.4275 - Intraocular fluid.

    Science.gov (United States)

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4275 Intraocular fluid. (a) Identification. An intraocular fluid is a device consisting of a nongaseous fluid intended to be introduced into the eye to aid... section 515 of the act is required before this device may be commercially distributed. See § 886.3. ...

  11. Radiation curing applications of palm oil acrylates

    International Nuclear Information System (INIS)

    Mohd Hilmi Mahmood; Khairul Zaman; Rida, Anak Tajau; Mek Zah Salleh; Rosley Che Ismail

    2007-01-01

    Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

  12. Interactions between Therapeutic Proteins and Acrylic Acid Leachable.

    Science.gov (United States)

    Liu, Dengfeng; Nashed-Samuel, Yasser; Bondarenko, Pavel V; Brems, David N; Ren, Da

    2012-01-01

    Leachables are chemical compounds that migrate from manufacturing equipment, primary containers and closure systems, and packaging components into biopharmaceutical and pharmaceutical products. Acrylic acid (at concentration around 5 μg/mL) was detected as leachable in syringes from one of the potential vendors (X syringes). In order to evaluate the potential impact of acrylic acid on therapeutic proteins, an IgG 2 molecule was filled into a sterilized X syringe and then incubated at 45 °C for 45 days in a pH 5 acetate buffer. We discovered that acrylic acid can interact with proteins at three different sites: (1) the lysine side chain, (2) the N-terminus, and (3) the histidine side chain, by the Michael reaction. In this report, the direct interactions between acrylic acid leachable and a biopharmaceutical product were demonstrated and the reaction mechanism was proposed. Even thought a small amount (from 0.02% to 0.3%) of protein was found to be modified by acrylic acid, the modified protein can potentially be harmful due to the toxicity of acrylic acid. After being modified by acrylic acid, the properties of the therapeutic protein may change due to charge and hydrophobicity variations. Acrylic acid was detected to migrate from syringes (Vendor X) into a therapeutic protein solution (at a concentration around 5 μg/mL). In this study, we discovered that acrylic acid can modify proteins at three different sites: (1) the lysine side chain, 2) the N-terminus, and 3) the histidine side chain, by the Michael reaction. In this report, the direct interactions between acrylic acid leachable and a biopharmaceutical product were demonstrated and the reaction mechanism was proposed.

  13. Dynamical mechanical analysis of photocrosslinked hyperbranched urethane acrylates

    Directory of Open Access Journals (Sweden)

    BRANKO DUNJIC

    2004-06-01

    Full Text Available A series of acrylate functionalized samples based on hyperbranched hydroxy-terminated polyesters with different molecular weights and different degrees of acrylation were synthesized. The obtained urethane acrylates were slightly yellow viscose liquids. Their composition was characterized by FTIR and 1H-NMR spectroscopy and their molecular weights were measured by GPC. All the synthesized samples were diluted with 25 wt.% 1,4-butanediol dimethacrylate (BDDM. The rheological properties of the uncured samples and the dynamic mechanical properties of the UV cured samples were examined. All the samples exhibit Newtonian behavior, which indicates the absence of physical entanglements in these polymers. The viscosity increases with increasing number of acrylic groups per molecule. The glass transition temperature of the UV cured samples increases with increasing the number of acrylic groups per molecule. The value of the storage modulus in the rubber-elastic plateau and the cross-link density increase with increasing number of acrylic groups per molecule. The formed networks are inhomogeneous and the residual unsaturation is the highest in the samples with the largest number of acrylic groups per molecule.

  14. A Case Report of Intraocular Metastasis Treated with Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ok Bae; Byun, Sang Jun; Kim, Kwang Soo; Kim, Jin Hee [Keimyung University School of Medicine, Daegu (Korea, Republic of); Lee, Ho Jun [Daegu Catholic University School of Medicine, Daegu (Korea, Republic of)

    2009-09-15

    Intraocular metastasis is the most common malignancy of the eye. The frequency of intraocular metastasis in all the patients dying of cancer is about 12% and ocular metastases will be detected more frequently in the future because the patients with malignant tumor are now living longer. Intraocular metastasis can cause a serious clinical problem such as blindness. The early recognition and treatment of intraocular metastasis are very important clinical oncologic issues to maintain vision and to maximize the quality of life. However, significance of intraocular metastasis is still under-evaluated for practicing oncologists. External beam radiotherapy is a safe, effective palliative treatment in terms of preserving both the vision and the eye globe.

  15. 21 CFR 886.4270 - Intraocular gas.

    Science.gov (United States)

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4270 Intraocular gas. (a) Identification. An intraocular gas is a device consisting of a gaseous fluid intended to be introduced into the eye to place pressure... required. As of May 28, 1976, an approval under section 515 of the act is required before this device may...

  16. Analysis of luminosity distributions of strong lensing galaxies: subtraction of diffuse lensed signal

    Science.gov (United States)

    Biernaux, J.; Magain, P.; Hauret, C.

    2017-08-01

    Context. Strong gravitational lensing gives access to the total mass distribution of galaxies. It can unveil a great deal of information about the lenses' dark matter content when combined with the study of the lenses' light profile. However, gravitational lensing galaxies, by definition, appear surrounded by lensed signal, both point-like and diffuse, that is irrelevant to the lens flux. Therefore, the observer is most often restricted to studying the innermost portions of the galaxy, where classical fitting methods show some instabilities. Aims: We aim at subtracting that lensed signal and at characterising some lenses' light profile by computing their shape parameters (half-light radius, ellipticity, and position angle). Our objective is to evaluate the total integrated flux in an aperture the size of the Einstein ring in order to obtain a robust estimate of the quantity of ordinary (luminous) matter in each system. Methods: We are expanding the work we started in a previous paper that consisted in subtracting point-like lensed images and in independently measuring each shape parameter. We improve it by designing a subtraction of the diffuse lensed signal, based only on one simple hypothesis of symmetry. We apply it to the cases where it proves to be necessary. This extra step improves our study of the shape parameters and we refine it even more by upgrading our half-light radius measurement method. We also calculate the impact of our specific image processing on the error bars. Results: The diffuse lensed signal subtraction makes it possible to study a larger portion of relevant galactic flux, as the radius of the fitting region increases by on average 17%. We retrieve new half-light radii values that are on average 11% smaller than in our previous work, although the uncertainties overlap in most cases. This shows that not taking the diffuse lensed signal into account may lead to a significant overestimate of the half-light radius. We are also able to measure

  17. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate polymer...

  18. Differences of Longitudinal Chromatic Aberration (LCA) between Eyes with Intraocular Lenses from Different Manufacturers

    Science.gov (United States)

    Nakajima, Masashi; Hiraoka, Takahiro; Yamamoto, Toshiya; Takagi, Seiu; Hirohara, Yoko; Oshika, Tetsuro

    2016-01-01

    Several researchers have studied the longitudinal chromatic aberration (LCA) of eyes implanted with an intraocular lens (IOL). We investigated the LCA of eyes implanted with yellow-colored IOLs from three different manufacturers: Alcon Inc., HOYA Corp., and AMO Inc. The number of subjects was 11, 16, and 16, respectively. The LCA of eyes implanted with SN60WF and SN60AT (Alcon Inc.), and with XY-1 (HOYA Corp.), was the same as that of phakic eyes. The LCA of eyes with ZCB00V (AMO Inc.) was smaller than that of phakic eyes. The LCA of eyes implanted with Alcon’s and HOYA’s IOLs, but not the LCA of eyes implanted with AMO’s IOLs, was positively correlated with the powers of the IOLs. We also performed simulations to verify the impacts of LCA on visual performance for 4-mm pupil diameter; the simulations were a polychromatic modulation transfer function (MTF) and a visual Strehl ratio computed on the basis of an optical transfer function (VSOTF). We concluded that the differences between the LCA of different manufacturers do not affect visual performances when some extent of higher-order aberration (HOA) exists. The smaller HOA of AMO IOLs may enhance visual performance. PMID:27258141

  19. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-ethyl acrylate copolymers. 177.1320... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1320 Ethylene-ethyl acrylate copolymers. Ethylene-ethyl acrylate copolymers may be safely used to produce packaging materials, containers...

  20. Efectividad de la lente intraocular ACRI. SMART 46-S en la cirugía de catarata por microincisiones Effectiveness of the intraocular lens ACRI SMART 46-S in micro-incision cataract surgery

    Directory of Open Access Journals (Sweden)

    Juan Raúl Hernández Silva

    2007-12-01

    catarata, también permitiría desarrollar en el futuro materiales y tecnologías que abrirían nuevos caminos para la cirugía oftalmológica, y la aplicación de parámetros facodinámicos óptimos conllevaría a un bajo porcentaje de complicaciones.Improvement and application of an industry devoted to modernize intraocular lenses and surgical tools have prompted a set of advances that allow optimizing, correcting and refining the surgical techniques for cataract surgery, particularly phacoemulsification. The most important aspect in this chain of advacements is aimed at reducing the surgical incision size in order to avoid a significant number of complications that are relatively frequent when using conventional extracapsular and intracapsular surgeries with over 10mm incisions. At present, new surgical techniques such as microincision cataract surgery have been developed. A retrospective and descriptive study was performed in 27 patients (eyes diagnosed with pre-senile and senile cataract, who were surgically treated with microincision phacoemulsification and received the implant of an ACRi Smart 46.S 11 x 6mm acrylic intraocular lens in the posterior chamber at the Ocular Microsurgery Center of “Ramón Pando Ferrer” Ophthalmology Institute in the period from January 2004 to January 2005. It was found that most of cases were older than 50 years; the best corrected visual acuity recovered significantly in the postoperative period and induced astigmatism was low. Regarding the used phacodynamic parameters, the ultrasound power was generally low. There were few complications, being vitreous detachment secondary to break in the posterior capsule. It was concluded that microincision cataract surgery with Acri Smart 46 S lens implant is a valid, safe and effective choice of catract treatment that will allow developing in the future materials and technologies which would open up new paths for eye surgery, and also the use of optimal phacodynamic parameters would lead to a

  1. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

  2. Outcomes of presbyopia-correcting intraocular lenses after laser in situ keratomileusis.

    Science.gov (United States)

    Chow, Sharon S W; Chan, Tommy C Y; Ng, Alex L K; Kwok, Alvin K H

    2018-03-28

    Laser in situ keratomileusis (LASIK) is the most common refractive surgery in young patients, which aims at providing a clear distance vision without the use of spectacles. With time, these patients develop symptomatic cataract, which affects activities of daily living, and to improve visual acuity, intraocular lens (IOL) implantation can be considered. In post-myopic LASIK patients, to allow continuation of spectacle independence, the implantation of presbyopia-correcting IOLs is a suitable option. The purpose of this retrospective case series is to report the visual outcome and quality in post-myopic LASIK eyes after the implantation of AT LISA tri839MP IOL. Twenty eyes of 13 patients with history of myopic LASIK within 20 years underwent phacoemulsification by one single surgeon. All eyes were implanted with AT LISA tri839PMP IOL, and their outcomes were evaluated at 6 months postoperation. The mean postoperative uncorrected distance visual acuity (VA) is 0.28 ± 0.29, while the corrected distance VA is 0.06 ± 0.14. The mean postoperative uncorrected near VA is 0.02 ± 0.05, while the corrected near VA is 0.01 ± 0.02. The mean postoperative manifest refraction spherical equivalent (SE) is - 0.92 ± 0.76D. There is a statistically significant difference between the preoperative and postoperative refraction (p = 0.02), which shows a postoperative myopic shift. There is also a statistically significant difference between the mean targeted SE and postoperative manifest refraction SE (p = 0.00). Only one out of 20 eyes (5%) reported halo and glare symptoms. Ten out of 20 eyes (50%) are able to achieve spectacles independence. In conclusion, in post-myopic LASIK eyes, AT LISA tri839MP provides a good visual outcome at both near and distance, but is more predictable at near than at distance. There is a myopic shift in the postoperative SE. Visual quality is satisfactory and has not been exacerbated. Most patients can remain to be

  3. A common humoral background of intraocular and arterial blood pressure dysregulation.

    Science.gov (United States)

    Skrzypecki, Janusz; Grabska-Liberek, Iwona; Przybek, Joanna; Ufnal, Marcin

    2018-03-01

    It has been postulated that intraocular pressure, an important glaucoma risk factor, correlates positively with arterial blood pressure (blood pressure). However, results of experimental and clinical studies are often contradictory. It is hypothesized that, in some hypertensive patients, disturbances in intraocular pressure regulation may depend on biological effects of blood borne hormones underlying a particular type of hypertension, rather than on blood pressure level itself. This review compares the effects of hormones on blood pressure and intraocular pressure, in order to identify a hormonal profile of hypertensive patients with an increased risk of intraocular pressure surge. The PUBMED database was searched to identify pre-clinical and clinical studies investigating the role of angiotensin II, vasopressin, adrenaline, noradrenaline, prostaglandins, and gaseous transmitters in the regulation of blood pressure and intraocular pressure. Studies included in the review suggest that intraocular and blood pressures often follow a different pattern of response to the same hormone. For example, vasopressin increases blood pressure, but decreases intraocular pressure. In contrast, high level of nitric oxide decreases blood pressure, but increases intraocular pressure. Arterial hypertension is associated with altered levels of blood borne hormones. Contradicting results of studies on the relationship between arterial hypertension and intraocular pressure might be partially explained by diverse effects of hormones on arterial and intraocular pressures. Further studies are needed to evaluate if hormonal profiling may help to identify glaucoma-prone patients.

  4. Effects of Novel Structure Bonding Materials on Properties of Aeronautical Acrylic

    Directory of Open Access Journals (Sweden)

    LI Zhisheng

    2017-06-01

    Full Text Available Novel structure bonding materials, J-351 epoxy adhesive film with low curing temperature and liquid modified acrylate SY-50s adhesive were chosen and characterized. The effects of adhesives on the mechanical properties of acrylic were studied. The results reveal that both adhesives have excellent bonding properties to acrylic. The stress-solvent crazing value of J-351 is higher than that of SY-50s. With the application of adhesive on the surface, mechanical properties of acrylic are declined. Casting acrylic shows more drastic decline than that of oriented acrylic. Through the characterization of fracture surface, we find that fracture of tensile sample derives from the side with adhesive. Mechanical properties of acrylic are more sensitive to SY-50s, because the liquid adhesive presents integrate bonding interface with acrylic. The interface between J-351 and acrylic is clear, making acrylic insensitive to J-351 film. Edge attachment strength of samples bonded with J-351 are higher than that of samples bonded with SY-50s due to the effects of adhesives on acrylic. J-351 epoxy adhesive film presents preferable application performance in the structure bonding of aeronautical acrylic.

  5. Acoustic lenses

    International Nuclear Information System (INIS)

    Kittmer, C.A.

    1983-03-01

    Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

  6. Advances in acrylic-alkyd hybrid synthesis and characterization

    Science.gov (United States)

    Dziczkowski, Jamie

    2008-10-01

    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  7. Quality of vision in patients implanted with aspherical and spherical intraocular lens: Intraindividual comparison

    Directory of Open Access Journals (Sweden)

    Francesco Semeraro

    2014-01-01

    Full Text Available Aims: To compare the quality of vision in pseudophakic patients implanted with aspherical and spherical intraocular lenses (IOLs. Materials and Methods: Randomized prospective longitudinal intrapatient comparison between aspherical and spherical IOLs performed on 22 patients who underwent bilateral cataract surgery. Best corrected visual acuity, subjective contrast sensitivity, Strehl ratio and spherical aberrations (SA, and higher order wavefront aberrations for a 3.5 mm and a 6.0 mm pupil were measured after 3 months of cataract surgery. Results: SA (Z4,0 decreased significantly in eyes with aspherical IOL implant (P = 0.004. Modulation transfer function (MTF and point spread function (PSF resulted no significant difference between the two groups (P = 0.87; P = 0.32. Conclusion: Although the SA is significantly lower in eyes implanted with aspherical IOL, the quality of vision determined with MTF and PSF does not significantly differ for subjective and objective parameters that were analyzed.

  8. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  9. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    International Nuclear Information System (INIS)

    Ghim, Deoukchen; Kim, Jung Hyeun

    2016-01-01

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T g of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  10. Additive manufacturing of tunable lenses

    Science.gov (United States)

    Schlichting, Katja; Novak, Tobias; Heinrich, Andreas

    2017-02-01

    Individual additive manufacturing of optical systems based on 3D Printing offers varied possibilities in design and usage. In addition to the additive manufacturing procedure, the usage of tunable lenses allows further advantages for intelligent optical systems. Our goal is to bring the advantages of additive manufacturing together with the huge potential of tunable lenses. We produced tunable lenses as a bundle without any further processing steps, like polishing. The lenses were designed and directly printed with a 3D Printer as a package. The design contains the membrane as an optical part as well as the mechanical parts of the lens, like the attachments for the sleeves which contain the oil. The dynamic optical lenses were filled with an oil. The focal length of the lenses changes due to a change of the radius of curvature. This change is caused by changing the pressure in the inside of the lens. In addition to that, we designed lenses with special structures to obtain different areas with an individual optical power. We want to discuss the huge potential of this technology for several applications. Further, an appropriate controlling system is needed. Wéll show the possibilities to control and regulate the optical power of the lenses. The lenses could be used for illumination tasks, and in the future, for individual measurement tasks. The main advantage is the individuality and the possibility to create an individual design which completely fulfills the requirements for any specific application.

  11. Amylase catalyzed synthesis of glycosyl acrylates and their polymerization

    NARCIS (Netherlands)

    Kloosterman, Wouter M.J.; Jovanovic, Danijela; Brouwer, Sander; Loos, Katja

    2014-01-01

    The enzymatic synthesis of novel (di)saccharide acrylates from starch and 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate (2-HEA, 2-HEMA and 4-HBA) catalyzed by various commercially available amylase preparations is demonstrated. Both liquefaction and

  12. Nanofocusing refractive X-ray lenses

    Energy Technology Data Exchange (ETDEWEB)

    Boye, Pit

    2010-02-05

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  13. Nanofocusing refractive X-ray lenses

    International Nuclear Information System (INIS)

    Boye, Pit

    2010-01-01

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  14. Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

    Directory of Open Access Journals (Sweden)

    Edwin Murillo

    Full Text Available Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR, methyl methacrylate (MMA, butyl acrylate (BA and acrylic acid (AA, by using benzoyl peroxide (BPO and ammonium persulfate (AP as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC, nuclear magnetic resonance (NMR and gel permeation chromatography (GPC. The conversion percentage, glass transition temperature (Tg, content of acrylic polymer (determined by soxhlet extraction and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly monomodal. The film properties (gloss, flexibility, adhesion and drying time of the HBRAA were good.

  15. Allergic contact dermatitis to acrylates in disposable blue diathermy pads.

    Science.gov (United States)

    Sidhu, S. K.; Shaw, S.

    1999-01-01

    We report 2 cases of elicitation of allergic contact dermatitis to acrylates from disposable blue diathermy pads used on patients who underwent routine surgery. Their reactions were severe, and took approximately 5 weeks to resolve. Both patients gave a prior history of finger tip dermatitis following the use of artificial sculptured acrylic nails, which is a common, but poorly reported, cause of acrylate allergy. Patch testing subsequently confirmed allergies to multiple acrylates present in both the conducting gel of disposable blue diathermy pads, and artificial sculptured acrylic nails. We advocate careful history taking prior to surgery to avoid unnecessary exposure to acrylates in patients already sensitized. Images Figure 1 Figure 2 PMID:10364952

  16. Palm oil based polyols for acrylated polyurethane production

    International Nuclear Information System (INIS)

    Rida Tajau; Mohd Hilmi Mahmood; Mek Zah Salleh; Khairul Zaman Mohd Dahlan; Rosley Che Ismail

    2006-01-01

    Palm oil becomes important renewable resources for the production of polyols for the polyurethane manufacturing industry. The main raw materials used for the production of acrylated polyurethane are polyols, isocyanates and hydroxyl terminated acrylate compounds. In these studies, polyurethane based natural polymer (palm oil), i.e., POBUA (Palm Oil Based Urethane Acrylate) were prepared from three different types of palm oil based polyols i.e., epoxidised palm oil (EPOP), palm oil oleic acid and refined, bleached and deodorized (RBD) palm olein based polyols. The performances of these three acrylated polyurethanes when used for coatings and adhesives were determined and compared with each other. (Author)

  17. Lente intra-ocular multifocal difrativa apodizada: resultados Diffractive apodized multifocal intraocular lens: results

    Directory of Open Access Journals (Sweden)

    Virgilio Centurion

    2007-12-01

    Full Text Available OBJETIVO: Mostrar os resultados visuais e refracionais com lente intra-ocular multifocal difrativa apodizada. MÉTODOS: Estudo de 100 olhos de 50 pacientes com catarata, submetidos à facoemulsificação com implante bilateral de lente intra-ocular (LIO multifocal difrativa apodizada. Foi avaliada a acuidade visual binocular sem e com correção para longe e perto, a previsibilidade refracional e a freqüência de uso de óculos. RESULTADOS: A acuidade visual sem correção para longe foi de e " 20/30 em 97,56% dos olhos operados e e" J2 em 100%, sendo que 82% dos pacientes nunca usam óculos e 16% usam de forma esporádica. CONCLUSÃO: A LIO multifocal difrativa apodizada mostrou ser uma opção previsível, reproduzível e segura na correção dos vícios de refração para longe e perto durante a cirurgia da catarata, permitindo elevado índice de independência ao uso de óculos.OBJECTIVE: To show visual and refraction results using multifocal diffractive apodized intraocular lens. METHODS: The study of 100 eyes of 50 patients with cataract, submitted to phacoemulsification with bilateral implant of multifocal diffractive apodized intraocular lens (IOL. Binocular visual acuity was evaluated with and without correction for near and distance, and refraction previsibility and frequency of wearing glasses. RESULTS: Visual acuity without correction for distance was e" 20/30 in 97.56% of eyes operated on and e" J2 in 100%, of these 82% of patients never wear glasses and 16% wear glasses sporadically. CONCLUSION: Multifocal diffractive apodized IOL proved to be a foreseeable option, reproducible and safe in the correction of refraction errors for distance and near during cataract surgery, enabling a high rate of independence from the use of glasses.

  18. Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

    OpenAIRE

    Petrov, P. (Petar); Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S. (Spiro); Irache, J.M. (Juan Manuel); Müller, A.H.E. (Axel H.E.)

    2013-01-01

    The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

  19. Bond strength test of acrylic artificial teeth with prosthetic base

    Directory of Open Access Journals (Sweden)

    Erna Kurnikasari

    2008-07-01

    Full Text Available Denture consists of acrylic artificial teeth and acrylic prothesis base bond chemically with a bond strength of 315 kgF/cm2. Most of the commercial acrylic artificial teeth do not specify their specifications and all of those acrylic artificial teeth do not include mechanical data (bond strength. The aim of this study is to discover which acrylic artificial teeth meet ADA specification no. 15. This study is a descriptive analytic study performed to 5 acrylic artificial teeth posterior brands commonly used by dentists and technicians. From each brand, 3 sample teeth were taken. The acrylic artificial teeth were prepared into a rectangular shape and were attached between acrylic prothesis base simulation and jigs. The sample was given tensile load using a Universal Testing Machine. The amount of force that causes the teeth to be fractured was recorded and the bond strength was calculated. The results of the study show that the average value for the five acrylic artificial teeth for the five brands were as followed: Brand A, 125.993 kgF/cm2; B, 188.457 kgF/cm2; C, 175.880 kgF/cm2; D, 153.373 kgF/cm2; E, 82.839 kgF/cm2. The data can be tested statistically by using One Way ANOVA test and Dunnett test (alpha = 0.05. From the study, it is concluded that the five acrylic artificial teeth have a bond strength below the ADA specification no. 15.

  20. Analysis of poly(styrene-co-methyl acrylate) and poly(styrene-co-butyl acrylate) by high-performance liquid chromatography

    NARCIS (Netherlands)

    Sparidans, R.W.; Claessens, H.A.; van Doremaele, G.H.J.; Herk, van A.M.

    1990-01-01

    Poly(styrene—co-methyl acrylate) and poly(styrene—co-butyl acrylate) were separated according to their chemical composition by gradient elution. The chromatographic separation on silica was optimized for a gradient ranging from n-heptane as a non-solvent to dichloromethane containing a small amount

  1. Capsulorhexis contraction after cataract surgery: Comparison of sharp anterior edge and modified anterior edge acrylic intraocular lenses

    DEFF Research Database (Denmark)

    Corydon, C.; Lindholt, M.; Knudsen, E.B.

    2007-01-01

    eyes) were included in a prospective randomized study. All had phacoemulsification followed by implantation of an IOL with a modified anterior edge (38 eyes) or a sharp anterior edge (46 eyes). One day (baseline) and 3 months postoperatively, the area of the anterior capsule opening was measured using...... retroillumination photographs. RESULTS: There was a significant reduction in the area of the anterior capsule opening from 1 day to 3 months postoperatively in both groups (Psharp...

  2. Relation between intraocular pressure and size of transverse sinuses

    Energy Technology Data Exchange (ETDEWEB)

    Kantarci, Mecit; Onbas, Omer; Alper, Fatih; Okur, Adnan [Atatuerk University, Department of Radiology, Medical Faculty, Erzurum (Turkey); Dane, Senol; Gumustekin, Kenan [Atatuerk University, Department of Physiology, Medical Faculty, Erzurum (Turkey); Aslankurt, Murat [Atatuerk University, Department of Ophtalmatology, Medical Faculty, Erzurum (Turkey); Yazici, Ahmet Taylan [Beyoglu Goez Egitim ve Arastirma Hastanesi, Istanbul (Turkey)

    2005-01-01

    There are asymmetries in the sizes of transverse sinus and intraocular pressure. The purpose of this study was to investigate possible relationships between the asymmetry of transverse sinuses in TOF MR venography and intraocular pressures of right and left eyes. In this study, subjects were 63 male and 42 female medical school students, aged 18-21 years (mean{+-}SD; 19.72{+-}0.67 years). Subjects with neurological and ophthalmologic disease, particularly dural sinus thrombosis, myopia, trauma and glaucoma, were excluded the study. Subjects were divided into five groups according to the magnitudes of the right- and left-transverse sinuses in MR venography results. There is a functional relation between intraocular pressures of the right and left eyes and asymmetry of the transverse sinus. If the transverse sinus on one side is larger and its venous drainage is greater, the intraocular pressure of the eye on this side is lower. It can be speculated that the transverse sinus size may be associated with pathogenesis of diseases with increased intraocular pressure such as glaucoma. We aim to determine the relation between the size and drainage of transverse sinuses in TOF MR venography and intraocular pressure in patients with open-angle glaucoma in our next study. (orig.)

  3. Relation between intraocular pressure and size of transverse sinuses

    International Nuclear Information System (INIS)

    Kantarci, Mecit; Onbas, Omer; Alper, Fatih; Okur, Adnan; Dane, Senol; Gumustekin, Kenan; Aslankurt, Murat; Yazici, Ahmet Taylan

    2005-01-01

    There are asymmetries in the sizes of transverse sinus and intraocular pressure. The purpose of this study was to investigate possible relationships between the asymmetry of transverse sinuses in TOF MR venography and intraocular pressures of right and left eyes. In this study, subjects were 63 male and 42 female medical school students, aged 18-21 years (mean±SD; 19.72±0.67 years). Subjects with neurological and ophthalmologic disease, particularly dural sinus thrombosis, myopia, trauma and glaucoma, were excluded the study. Subjects were divided into five groups according to the magnitudes of the right- and left-transverse sinuses in MR venography results. There is a functional relation between intraocular pressures of the right and left eyes and asymmetry of the transverse sinus. If the transverse sinus on one side is larger and its venous drainage is greater, the intraocular pressure of the eye on this side is lower. It can be speculated that the transverse sinus size may be associated with pathogenesis of diseases with increased intraocular pressure such as glaucoma. We aim to determine the relation between the size and drainage of transverse sinuses in TOF MR venography and intraocular pressure in patients with open-angle glaucoma in our next study. (orig.)

  4. Contact allergy to epoxy (meth)acrylates.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Jungewelter, Soile; Henriks-Eckerman, Maj-Len; Kuuliala, Outi; Jolanki, Riitta

    2009-07-01

    Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. We reviewed the 1994-2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA.

  5. Statistics of gravitational lenses. III. Astrophysical consequences of quasar lensing

    International Nuclear Information System (INIS)

    Ostriker, J.P.; Vietri, M.

    1986-01-01

    The method of Schmidt and Green (1983) for calculating the luminosity function of quasars is combined with gravitational-lensing theory to compute expected properties of lensed systems. Multiple quasar images produced by galaxies are of order 0.001 of the observed quasars, with the numbers over the whole sky calculated to be (0.86, 120, 1600) to limiting B magnitudes of (16, 19, 22). The amount of false evolution is small except for an interesting subset of apparently bright, large-redshift objects for which minilensing by starlike objects may be important. Some of the BL Lac objects may be in this category, with the galaxy identified as the parent object really a foreground object within which stars have lensed a background optically violent variable quasar. 24 references

  6. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...

  7. Gravitational lensing

    CERN Document Server

    Dodelson, Scott

    2017-01-01

    Gravitational lensing is a consequence of general relativity, where the gravitational force due to a massive object bends the paths of light originating from distant objects lying behind it. Using very little general relativity and no higher level mathematics, this text presents the basics of gravitational lensing, focusing on the equations needed to understand the phenomena. It then applies them to a diverse set of topics, including multiply imaged objects, time delays, extrasolar planets, microlensing, cluster masses, galaxy shape measurements, cosmic shear, and lensing of the cosmic microwave background. This approach allows undergraduate students and others to get quickly up to speed on the basics and the important issues. The text will be especially relevant as large surveys such as LSST and Euclid begin to dominate the astronomical landscape. Designed for a one semester course, it is accessible to anyone with two years of undergraduate physics background.

  8. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Directory of Open Access Journals (Sweden)

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  9. 30 CFR 18.30 - Windows and lenses.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Windows and lenses. 18.30 Section 18.30 Mineral... § 18.30 Windows and lenses. (a) MSHA may waive testing of materials for windows or lenses except headlight lenses. When tested, material for windows or lenses shall meet the test requirements prescribed in...

  10. Ionizing radiation method for forming acrylic pressure sensitive adhesives and coated substrates

    International Nuclear Information System (INIS)

    Dowbenko, R.; Christenson, R.M.

    1975-01-01

    Pressure-sensitive adhesive having improved adhesive properties are formed by subjecting a mixture comprising a monomer selected from the group consisting of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, N-alkoxymethylacrylamides, and N-alkoxymethylmethacrylamides, and a homopolymer or copolymer selected from the group consisting of polymers of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, acrylamide, methacrylamide, N-(substituted alkyl) acrylamides, N-(substituted alkyl) methacrylamides, alkyl acrylamides, alkyl methacrylamides, and N-alkoxymethylacrylamides and N-alkoxymethylmethacrylamides to ionizing irradiation. The adhesive material finds utility as binding resins in laminates, coatings on substrates, and as film adhesives. (U.S.)

  11. [Endoscopically controlled optimization of trans-scleral suture fixation of posterior chamber lenses in the ciliary sulcus].

    Science.gov (United States)

    Althaus, C; Sundmacher, R

    1993-08-01

    Two technical difficulties have to be overcome in transscleral suture fixation of posterior chamber intraocular lenses (PCL) in the ciliary sulcus: first, exact needle penetration through the sulcus, and second, exact positioning of the PCL haptics in the sulcus. Incongruence of the two may lead to long-term complications by compression or even strangulation of ciliary processes. Intraocular endoscopy was used intraoperatively to visualize the site of needle penetration and the final location of the haptics in patients. It turned out that with our previously described standard techniques the precision was far less than anticipated. Thus, new technical ways had to be sought to improve the precision of positioning. In secondary implantation without perforating keratoplasty we achieved the best results when the needle was passed ab externo before opening the eye and before anterior vitrectomy, taking advantage of a precisely prepared sclerocorneal zone. Passing the needle ab externo in an already hypotonic eyeball gives much less precise results. In combination with perforating keratoplasty with an open-sky approach, needle penetration ab interno is reliable. Correct positioning of the PCL haptics is at least as difficult as correct needle penetration, a fact which up to now has mostly been ignored. In 33 consecutively operated eyes the technique of implantation and PCL design was varied under endoscopical control.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. COMPARATIVE ANALYSIS OF WATER SORPTION BY DIFFERENT ACRYLIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Milena Kostić

    2014-06-01

    Full Text Available Acrylic materials are used daily for the production of mobile dental restorations and orthodontic appliances. The presence of residual monomer, as a product of incomplete polymerisation of material, results in more porous structure of the material, which greatly reduces the mechanical and physical quality of the acrylic restorations and increases the absorption of liquids. The aim of this study was to examine the water absorption of different types of resin material. In the study it was assumed that the cold polymerized acrylates show a greater potential for absorbing fluid from the environment in relation to the hot polymerized acrylic. The study included two hot and two cold polymerized acrylates, and cold polymerized acrylate impregnated with aesthetic pearls. In order to determine the degree of water absorption, the mass of the samples was measured before and after one day, seven days and thirty days of immersion in a water bath of body temperature. The tested hot and cold polymerized acrylates after immersion in water bath showed standard values of water absorption. The degree of water absorption was not significantly influenced by the type and manner of polymerisation. Water absorption values were significantly higher after seven days and thirty days of water storage relative to the observational period of one day.

  13. Scleral Fixation of Posteriorly Dislocated Intraocular Lenses by 23-Gauge Vitrectomy without Anterior Segment Approach

    Directory of Open Access Journals (Sweden)

    Jeroni Nadal

    2015-01-01

    Full Text Available Background. To evaluate visual outcomes, corneal changes, intraocular lens (IOL stability, and complications after repositioning posteriorly dislocated IOLs and sulcus fixation with polyester sutures. Design. Prospective consecutive case series. Setting. Institut Universitari Barraquer. Participants. 25 eyes of 25 patients with posteriorly dislocated IOL. Methods. The patients underwent 23-gauge vitrectomy via the sulcus to rescue dislocated IOLs and fix them to the scleral wall with a previously looped nonabsorbable polyester suture. Main Outcome Measures. Best corrected visual acuity (BCVA LogMAR, corneal astigmatism, endothelial cell count, IOL stability, and postoperative complications. Results. Mean follow-up time was 18.8 ± 10.9 months. Mean surgery time was 33 ± 2 minutes. Mean BCVA improved from 0.30 ± 0.48 before surgery to 0.18 ± 0.60 (p=0.015 at 1 month, which persisted to 12 months (0.18 ± 0.60. Neither corneal astigmatism nor endothelial cell count showed alterations 1 year after surgery. Complications included IOL subluxation in 1 eye (4%, vitreous hemorrhage in 2 eyes (8%, transient hypotony in 2 eyes (8%, and cystic macular edema in 1 eye (4%. No patients presented retinal detachment. Conclusion. This surgical technique proved successful in the management of dislocated IOL. Functional results were good and the complications were easily resolved.

  14. Scleral Fixation of Posteriorly Dislocated Intraocular Lenses by 23-Gauge Vitrectomy without Anterior Segment Approach.

    Science.gov (United States)

    Nadal, Jeroni; Kudsieh, Bachar; Casaroli-Marano, Ricardo P

    2015-01-01

    Background. To evaluate visual outcomes, corneal changes, intraocular lens (IOL) stability, and complications after repositioning posteriorly dislocated IOLs and sulcus fixation with polyester sutures. Design. Prospective consecutive case series. Setting. Institut Universitari Barraquer. Participants. 25 eyes of 25 patients with posteriorly dislocated IOL. Methods. The patients underwent 23-gauge vitrectomy via the sulcus to rescue dislocated IOLs and fix them to the scleral wall with a previously looped nonabsorbable polyester suture. Main Outcome Measures. Best corrected visual acuity (BCVA) LogMAR, corneal astigmatism, endothelial cell count, IOL stability, and postoperative complications. Results. Mean follow-up time was 18.8 ± 10.9 months. Mean surgery time was 33 ± 2 minutes. Mean BCVA improved from 0.30 ± 0.48 before surgery to 0.18 ± 0.60 (p = 0.015) at 1 month, which persisted to 12 months (0.18 ± 0.60). Neither corneal astigmatism nor endothelial cell count showed alterations 1 year after surgery. Complications included IOL subluxation in 1 eye (4%), vitreous hemorrhage in 2 eyes (8%), transient hypotony in 2 eyes (8%), and cystic macular edema in 1 eye (4%). No patients presented retinal detachment. Conclusion. This surgical technique proved successful in the management of dislocated IOL. Functional results were good and the complications were easily resolved.

  15. Synthesis and characterization of acrylated Parkia biglobosa ...

    African Journals Online (AJOL)

    The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum ...

  16. Gabor lenses

    International Nuclear Information System (INIS)

    Mobley, R.M.; Gamml, G.; Maschke, A.W.

    1979-01-01

    Stable operation of Gabor lenses has been reported by at least three experimental groups. At Brookhaven, several lens designs have been tried since February, 1978 with very good results. The lens concept is simple, operation is less complicated than anticipated, and the focussing strengths attainable make them very attractive alternatives to magnetic focussing for heavy ion beams at low energies. Results obtained with five different configurations are presented. The lenses work well, concern is now with fine details of their beam-optical performance

  17. Acute Retention of Urine Following Intraocular Surgery | Nwosu ...

    African Journals Online (AJOL)

    Hyperosmolar agents and carbonic anhydrase inhibitors are used to lower the intraocular pressure and thus minimize the chances of vitreous loss during intraocular surgery. However, these agents could precipitate urinary retention. This is a report on two elderly men who had perioperative acute urinary retention following ...

  18. [Treatment of acrylate wastewater by electrocatalytic reduction process].

    Science.gov (United States)

    Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

    2011-10-01

    High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.

  19. Design of a Test Bench for Intraocular Lens Optical Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Alba-Bueno, Francisco; Vega, Fidel; Millan, Maria S, E-mail: francisco.alba-bueno@upc.edu, E-mail: fvega@oo.upc.edu, E-mail: millan@oo.upc.edu [Departamento de Optica y Optometria, Universidad Politecnica de Cataluna, C/ Violinista Vellsola 37, 08222 Terrassa (Spain)

    2011-01-01

    The crystalline lens is the responsible for focusing at different distances (accommodation) in the human eye. This organ grows throughout life increasing in size and rigidity. Moreover, due this growth it loses transparency through life, and becomes gradually opacified causing what is known as cataracts. Cataract is the most common cause of visual loss in the world. At present, this visual loss is recoverable by surgery in which the opacified lens is destroyed (phacoemulsification) and replaced by the implantation of an intraocular lens (IOL). If the IOL implanted is mono-focal the patient loses its natural capacity of accommodation, and as a consequence they would depend on an external optic correction to focus at different distances. In order to avoid this dependency, multifocal IOLs designs have been developed. The multi-focality can be achieved by using either, a refractive surface with different radii of curvature (refractive IOLs) or incorporating a diffractive surface (diffractive IOLs). To analyze the optical quality of IOLs it is necessary to test them in an optical bench that agrees with the ISO119679-2 1999 standard (Ophthalmic implants. Intraocular lenses. Part 2. Optical Properties and Test Methods). In addition to analyze the IOLs according to the ISO standard, we have designed an optical bench that allows us to simulate the conditions of a real human eye. To do that, we will use artificial corneas with different amounts of optical aberrations and several illumination sources with different spectral distributions. Moreover, the design of the test bench includes the possibility of testing the IOLs under off-axis conditions as well as in the presence of decentration and/or tilt. Finally, the optical imaging quality of the IOLs is assessed by using common metrics like the Modulation Transfer Function (MTF), the Point Spread Function (PSF) and/or the Strehl ratio (SR), or via registration of the IOL's wavefront with a Hartmann-Shack sensor and its

  20. Spontaneous bilateral anterior partial in-the-bag intraocular lens dislocation following routine annual eye examination.

    Science.gov (United States)

    Ford, Joshua R; Werner, Liliana; Owen, Leah; Vasavada, Shail A; Crandall, Alan

    2014-09-01

    We present the case of an 81-year-old man with pseudoexfoliation syndrome (PXF) in whom spontaneous bilateral anterior partial in-the-bag intraocular lens (IOL) dislocation was diagnosed following a routine dilated examination that demonstrated only mild pseudophacodonesis with no evidence of subluxation. Uneventful cataract surgery with placement of single-piece hydrophobic acrylic posterior chamber IOLs had been performed in both eyes 7 years previously. Bilateral IOL repositioning with scleral fixation was performed to correct the dislocation. Postoperative examinations showed remarkable improvement in visual acuity and IOL stability. We hypothesize that zonular weakness secondary to PXF predisposed the patient to bilateral IOL partial dislocation. Pupil dilation in the setting of mild pseudophacodonesis at the time of routine examination may have been a precipitating factor. To our knowledge, bilateral IOL subluxation/dislocation has been described in a limited number of case reports. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  1. Gravitational lenses and cosmological evolution

    International Nuclear Information System (INIS)

    Peacock, J.A.

    1982-01-01

    The effect of gravitational lensing on the apparent cosmological evolution of extragalactic radio sources is investigated. Models for a lens population consisting of galaxies and clusters of galaxies are constructed and used to calculate the distribution of amplification factors caused by lensing. Although many objects at high redshifts are predicted to have flux densities altered by 10 to 20 per cent relative to a homogeneous universe, flux conservation implies that de-amplification is as common as amplification. The effects on cosmological evolution as inferred from source counts and redshift data are thus relatively small; the slope of the counts is not large enough for intrinsically rare lensing events of high amplitude to corrupt observed samples. Lensing effects may be of greater importance for optically selected quasars, where lenses of mass as low as approximately 10 -4 solar mass can cause large amplifications. (author)

  2. Intraocular osseous metaplasia. A clinico-pathological study

    OpenAIRE

    Vemuganti Geeta; Honavar Santosh; Jalali Subhadra

    2002-01-01

    Purpose: To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Methods: Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membra...

  3. Outcomes Associated With Concurrent Iris-Sutured Intraocular Lens Placement and Subluxated Crystalline Lens Extraction.

    Science.gov (United States)

    McClellan, Scott F; Soiberman, Uri; Gehlbach, Peter L; Murakami, Peter N; Stark, Walter J

    2015-08-01

    We have developed a novel surgical technique, to our knowledge, for the management of subluxated crystalline lenses involving preplacement of an iris-sutured posterior chamber intraocular lens (PCIOL) before pars plana vitrectomy and lensectomy. To investigate the outcomes of eyes with subluxated crystalline lenses, predominantly a result of Marfan syndrome (14 eyes [58%]) or trauma (5 eyes [21%]), that underwent pars plana vitrectomy and lensectomy with placement of an iris-sutured PCIOL. We performed a retrospective, noncomparative case series of 24 eyes from 17 consecutive adult patients with surgically treated subluxated crystalline lenses presenting to the Wilmer Eye Institute at Johns Hopkins Hospital from October 6, 2006, through May 1, 2013. The mean (SD) postoperative follow-up was 24.4 (20.5) months for eyes with at least 6 months of follow-up (last date, October 13, 2014). We performed the analysis from January 21, 2014, through January 3, 2015. Improvement in best-corrected visual acuity using an automated Snellen chart and induction of astigmatism for eyes with at least 6 months of follow-up (n = 18) and IOL stability during follow-up for all eyes (n = 24). The mean (SD) age at surgery was 49.4 (10.7 [range, 29-67]) years. We found an improvement in mean (SD [95% CI]) best-corrected visual acuity from 0.66 (0.71 [0.30-1.02]) logMAR preoperatively (Snellen equivalent, approximately 20/90; range, 20/30 to hand motions) to 0.07 (0.11 [95% CI, 0.01-0.12]) logMAR postoperatively (Snellen equivalent, approximately 20/23; range, 20/15 to 20/50). We found little change in astigmatism postoperatively (mean change, -0.1 [95% CI, -0.5 to 0.13] diopters). Postoperative complications included retinal detachment (1 eye [4%]), retained cortical fragment (1 [4%]), cystoid macular edema (2 [8%]), and IOL subluxation (3 [13%]) owing to haptic slippage within 3 months of the procedure. The overall probability of successfully achieving placement of a centered iris

  4. Resultados da troca de lente intra-ocular de hidrogel opacificada

    Directory of Open Access Journals (Sweden)

    Salera Cristina Moreira

    2004-01-01

    Full Text Available OBJETIVO: Avaliar os resultados da explantação e substituição das lentes intra-oculares (LIO de hidrogel opacificadas. MÉTODOS: Foram analisados retrospectivamente os prontuários de 12 pacientes (15 olhos submetidos à explantação e substituição das lentes intra-oculares de hidrogel opacificadas. RESULTADOS: A opacificação das lentes intra-oculares de hidrogel causou perdas de linhas de visão em 13 olhos (86,7%. A troca das lentes intra-oculares opacificadas promoveu o ganho de linhas de visão em 11 olhos (73,3%. As complicações peroperatórias ocorreram em três olhos (20% e foram as seguintes: perda de óleo de silicone, ruptura total de zônula com perda do saco capsular e ruptura parcial de zônula. Durante a explantação das lentes intra-oculares foi necessária a realização de incisões relaxantes na borda da capsulorrexe anterior em três olhos (20% e em dois olhos (13,3% os hápticos foram cortados sendo retirada somente a zona óptica das lentes intra-oculares. CONCLUSÃO: A cirurgia para explantação e substituição das lentes intra-oculares opacificadas mostrou-se eficaz naqueles pacientes com perdas de linhas de visão (p > 0,05.

  5. Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

    2016-10-15

    Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

  6. Biocompatibility of acrylic resin after being soaked in sodium hypochlorite

    Directory of Open Access Journals (Sweden)

    Nike Hendrijatini

    2009-06-01

    Full Text Available Background: Acrylic resin as basic material for denture will stay on oral mucosa for a very long time. The polymerization of acrylic resin can be performed by conventional method and microwave, both produce different residual monomer at different toxicity. Acrylic resin can absorb solution, porous and possibly absorb disinfectantt as well, that may have toxic reaction with the tissue. Sodium Hypochlorite as removable denture disinfectant can be expected to be biocompatible to human body. The problem is how biocompatible acrylic resin which has been processed by conventional method and microwave method after being soaked in sodium hypochlorite solution. Purpose: The aim of this study was to understand in vitro biocompatibility of acrylic resin which has polimerated by conventional method and microwave after being soaked in sodium hypochlorite using tissue culture. Methods: Four groups of acrylic resin plate were produced, the first group was acrylic resin plate with microwave polymeration and soaked in sodium hypochlorite, the second group was acrylic resin plate with microwave polymeration but not soaked, the thirdwas one with conventional method and soaked and the last group was one with conventional method but not soaked, and in 1 control group. Each group consists of 7 plates. Biocompatibility test was performed in-vitro on each material using fibroblast tissue culture (BHK-21 cell-line. Result: The percentage between living cells and dead cells from materials which was given acrylic plate was wounted. The data was analyzed statistically with T test. Conclusion: The average value of living cells is higher in acrylic resin poimerization using microwave method compared to conventional method, in both soaked and non soaked (by sodium hypochlorite group. This means that sodium hypochlorite 0.5% was biocompatible to the mouth mucosa as removable denture disinfectant for 10 minutes soaking and washing afterwards.

  7. BAYESIAN INFERENCE OF CMB GRAVITATIONAL LENSING

    Energy Technology Data Exchange (ETDEWEB)

    Anderes, Ethan [Department of Statistics, University of California, Davis, CA 95616 (United States); Wandelt, Benjamin D.; Lavaux, Guilhem [Sorbonne Universités, UPMC Univ Paris 06 and CNRS, UMR7095, Institut d’Astrophysique de Paris, F-75014, Paris (France)

    2015-08-01

    The Planck satellite, along with several ground-based telescopes, has mapped the cosmic microwave background (CMB) at sufficient resolution and signal-to-noise so as to allow a detection of the subtle distortions due to the gravitational influence of the intervening matter distribution. A natural modeling approach is to write a Bayesian hierarchical model for the lensed CMB in terms of the unlensed CMB and the lensing potential. So far there has been no feasible algorithm for inferring the posterior distribution of the lensing potential from the lensed CMB map. We propose a solution that allows efficient Markov Chain Monte Carlo sampling from the joint posterior of the lensing potential and the unlensed CMB map using the Hamiltonian Monte Carlo technique. The main conceptual step in the solution is a re-parameterization of CMB lensing in terms of the lensed CMB and the “inverse lensing” potential. We demonstrate a fast implementation on simulated data, including noise and a sky cut, that uses a further acceleration based on a very mild approximation of the inverse lensing potential. We find that the resulting Markov Chain has short correlation lengths and excellent convergence properties, making it promising for applications to high-resolution CMB data sets in the future.

  8. Importance of intraocular pressure in glaucoma

    Science.gov (United States)

    Joos, Karen M.

    1999-06-01

    Glaucoma results in permanent vision loss and affects the peripheral vision initially. It is presented in 22.5 million people worldwide and is the 3rd cause of blindness. Present tonometers are not ideal for intraocular pressure measurements in all eyes. Of concern, PRK and LASIK may result in lower intraocular pressure readings. A challenges now exists for the development of a tonometer which can easily compensate for corneas with many parameters to avoid a future increase in normal-tension glaucoma or glaucoma which is advanced.

  9. Cosmology with weak lensing surveys

    International Nuclear Information System (INIS)

    Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan

    2008-01-01

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  10. Cosmology with weak lensing surveys

    Energy Technology Data Exchange (ETDEWEB)

    Munshi, Dipak [Institute of Astronomy, Madingley Road, Cambridge, CB3 OHA (United Kingdom); Astrophysics Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE (United Kingdom)], E-mail: munshi@ast.cam.ac.uk; Valageas, Patrick [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France); Waerbeke, Ludovic van [University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Heavens, Alan [SUPA - Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

    2008-06-15

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  11. clinical and experimental study

    OpenAIRE

    Tornow, Christoph

    2011-01-01

    Posterior capsule opacity (PCO) is a frequent complication in extracapsular cataract extraction in conjunction with an intraocular lens implant. Different studies have shown that a reduction in PCO frequency can be achieved via a number of factors. Lens design is a significant criterion in this process. In this study, two multifocal intraocular lenses (MIOLs) were compared. The design of these lenses differed due to their varying optical principles. They are the refractive MIOL A...

  12. Solid intraocular xanthogranuloma in three Miniature Schnauzer dogs.

    Science.gov (United States)

    Zarfoss, Mitzi K; Dubielzig, Richard R

    2007-01-01

    Macrophages that contain abundant intracytoplasmic lipid are called 'foam cells'. In four canine globes submitted to the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW), foam cells formed a solid intraocular mass. The purpose of this study was to describe the histopathologic findings in these cases. The electronic COPLOW database (1993-2006) was searched for the diagnosis of 'foam cell tumor'. Clinical history, gross pathology and histopathology (5-micron sections, hematoxylin and eosin and Alcian blue periodic acid Schiff) were reviewed in all cases. Cases were included if the globe was grossly filled by a solid mass and if all intraocular structures were effaced by lipid-laden foam cell macrophages admixed with birefringent, Alcian blue-positive crystals oriented in stellate patterns. All three patients (four globes) satisfying the selection criteria were Miniature Schnauzers. In all cases the clinical history included diabetes mellitus, hyperlipidemia and chronic bilateral uveitis that was interpreted to be lens-induced. All globes were enucleated because of glaucoma. The term solid intraocular xanthogranuloma was used to describe these cases because the intraocular contents were effaced by a solid mass of foam cells and birefringent crystals. The cases in this report suggest that diabetic Miniature Schnauzers with hyperlipidemia are at risk for lipid and macrophage-rich uveitis, which may in some cases form a solid inflammatory intraocular mass, precipitate glaucoma, and lead to enucleation.

  13. Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

    DEFF Research Database (Denmark)

    Johnston, Blair F.; Marshall, William G.; Parsons, Simon

    2014-01-01

    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a new...

  14. Chemo-enzymatic synthesis route to poly(glucosyl-acrylates) using glucosidase from almonds

    NARCIS (Netherlands)

    Kloosterman, Wouter M. J.; Roest, Steven; Priatna, Siti R.; Stavila, Erythrina; Loos, Katja

    2014-01-01

    Novel types of glucosyl-acrylate monomers are obtained by beta-glucosidase from almond catalyzed glycosidation reaction. The saccharide-acrylate monomers were synthesized by reaction of D-glucose with hydroxyl functional acrylates: 2-hydroxyethyl acrylate (2-HEA), 2-hydroxyethyl methacrylate

  15. Poly(alkyl acrylate) nonparticles

    International Nuclear Information System (INIS)

    Kreuter, J.

    1985-01-01

    This study deals with the preparation of poly(alkyl acrylic) and poly(alkyl cyanocrylic) nanoparticles. Nonoparticles are solid colloidal particles, consisting of macromolecular materials in which drugs or biologically active materials are dissolved, entrapped, and encapsulated, and/or to which the active substance is adsorbed or attached. Poly(alkyl acrylic) nanoparticles are much more slowly biodegradable than poly(alkyl cyanoacrylate) nanoparticles, and are thus more suitable for drug delivery purposes. Poly(methyl methacrylate) is the material of choice for the use of nanoparticles as an adjuvant for vaccines and are produced by emulsifier-free polymerization in aqueous media. The polymerization, which can be initiated with gamma rays or with potassium peroxodisulfate, is described

  16. Gravitational lenses

    International Nuclear Information System (INIS)

    Turner, E.L.

    1989-01-01

    The author discusses how gravitational lens studies is becoming a major focus of extragalactic astronomy and cosmology. This review is organized into five parts: an overview of the observational situation, a look at the state of theoretical work on lenses, a detailed look at three recently discovered types of lensing phenomena (luminous arcs, radio rings, quasar-galaxy associations), a review of progress on two old problems in lens studies (deriving unique lens mass distribution models, measurements of differential time delays), and an attempt to look into the future of lens studies

  17. Methods of fixation of intraocular lenses according to the anatomical structures in trauma eyes.

    Science.gov (United States)

    Fiorentzis, Miltiadis; Viestenz, Anja; Heichel, Jens; Seitz, Berthold; Hammer, Thomas; Viestenz, Arne

    2018-01-01

    Ocular trauma can lead to severe visual impairment and morbidity, depending on the anatomical structures affected. The main causes of ocular trauma include foreign bodies, impact by an object, falls, and chemicals. Most ocular traumas occur in children or young male adults. A meticulous slit lamp examination is crucial for assessing all anatomical structures. Trauma to the crystalline lens can result in dislocation, an intralenticular foreign body, cataract, fragmentation, and capsular breach. An intraocular lens (IOL) can endure subluxation or luxation under the conjunctiva, into the anterior chamber or the vitreous, or can be extruded. The surgical approach depends on the condition and morphology of the lens and the anatomical structures surrounding it. If there is capsular bag support, a secondary IOL can be placed in the sulcus using remnants of the damaged capsule. If there is no capsular bag support, a secondary IOL can be fixated to the anterior chamber angle, to the iris, or to the sclera. A detailed history of injury cannot always be obtained in trauma settings. Proper education, supervision, and certified safety eye protectors could prevent up to 90% of ocular injuries. Lens trauma can be treated with various surgical procedures and fixation techniques, which nevertheless require advanced surgical skills owing to the fine anatomical structure of the anterior segment. A careful surgical strategy should be established for a globe reconstruction after trauma with secondary lens implantation. Clin. Anat. 31:6-15, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Methacrylate and acrylate allergy in dental personnel.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Alanko, Kristiina; Kuuliala, Outi; Jolanki, Riitta

    2007-11-01

    Methacrylates are important allergens in dentistry. The study aimed to analyse patch test reactivity to 36 acrylic monomers in dental personnel in relation to exposure. We reviewed the test files at the Finnish Institute of Occupational Health from 1994 to 2006 for allergic reactions to acrylic monomers in dental personnel and analysed the clinical records of the sensitized patients. 32 patients had allergic reactions to acrylic monomers: 15 dental nurses, 9 dentists, and 8 dental technicians. The dentists and dental nurses were most commonly exposed to 2-hydroxyethyl methacrylate (2-HEMA), triethyleneglycol dimethacrylate (TREGDMA), and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA). 8 dentists and 12 dental nurses were allergic to 2-HEMA. The remaining dentist was positive to bis-GMA and other epoxy acrylates. The remaining 3 dental nurses reacted to diethyleneglycol diacrylate (DEGDA) or triethyleneglycol diacrylate (TREGDA), but not to monofunctional and multifunctional methacrylates. Our dental technicians were mainly exposed and sensitized to methyl methacrylate (MMA) and ethyleneglycol dimethacrylate (EGDMA). 1 technician reacted only to 2-HEMA, and another to ethyl methacrylate (EMA) and ethyl acrylate (EA). 2-HEMA was the most important allergen in dentists and dental nurses, and MMA and EGDMA in dental technicians. Reactions to bis-GMA, DEGDA, TREGDA, EMA and EA were relevant in some patients.

  19. Toxic Anterior Segment Syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Özlem Öner

    2011-12-01

    Full Text Available Toxic anterior segment syndrome (TASS is a sterile intraocular inflammation caused by noninfectious substances, resulting in extensive toxic damage to the intraocular tissues. Possible etiologic factors of TASS include surgical trauma, bacterial endotoxin, intraocular solutions with inappropriate pH and osmolality, preservatives, denatured ophthalmic viscosurgical devices (OVD, inadequate sterilization, cleaning and rinsing of surgical devices, intraocular lenses, polishing and sterilizing compounds which are related to intraocular lenses. The characteristic signs and symptoms such as blurred vision, corneal edema, hypopyon and nonreactive pupil usually occur 24 hours after the cataract surgery. The differential diagnosis of TASS from infectious endophthalmitis is important. The main treatment for TASS formation is prevention. TASS is a cataract surgery complication that is more commonly seen nowadays. In this article, the possible underlying causes as well as treatment and prevention methods of TASS are summarized. (Turk J Oph thal mol 2011; 41: 407-13

  20. The Increase of Intra-Abdominal Pressure Can Affect Intraocular Pressure

    Directory of Open Access Journals (Sweden)

    Ilhan Ece

    2015-01-01

    Full Text Available Objective. This study aims to explore the usage of intraocular pressure measurements as the early indicator of the increase in intra-abdominal pressure. Methods. In this prospective study, 40 patients undergoing elective surgery were included. Patients were divided into four groups of 10 patients. The control group (Group C was not subjected to laparoscopic intervention. Laparoscopic surgery was, respectively, performed with an intra-abdominal pressure of 9, 12, and 15 mmHg in Groups L (low, M (medium, and H (high pressure. Intraocular pressure was measured binocularly in each patient at three different times (before, during, and end of surgery using a contact tonometer. Results. Patients’ gender, age, body mass index (BMI, American Society of Anesthesiology (ASA class, and operative times were not different among the groups. No complications occurred with either the surgery or measurement of intraocular pressure. Intubation was associated with a severe rise in IOP (P<0.05. An increase in intraocular pressure was seen in groups M and H (P<0.05. Conclusion. Intraocular pressure was increased in the groups with an intra-abdominal pressure of 12 mmHg or more. Measuring the intraocular pressure might be a useful method to estimate the intra-abdominal pressure. This trial is registered with NCT02319213.

  1. Resultados de implante de lente intraocular en niños Results of intraocular lens implantation in children

    Directory of Open Access Journals (Sweden)

    Nashelly I. Mejía Cruz

    2007-12-01

    Full Text Available En este estudio se describen los resultados obtenidos del implante de lente intraocular en niños, quienes acudieron al servicio de Oftalmología Pediátrica de Instituto Cubano de oftalmología “Ramón Pando Ferrer” con el diagnóstico de catarata de diversas etiologías, en período comprendido entre abril del 2002 al 2005 cuyo seguimiento fue durante un año. En nuestro universo de estudio se determinan algunos parámetros como la edad del paciente, etiología de las cataratas, agudeza visual, defecto refractivo preoperatorio y posoperatorio. Se identificó el poder dióptrico del lente intraocular más frecuente, la presencia de complicaciones durante la cirugía y después de esta. Se evaluaron finalmente, los pacientes que requerían de tratamiento adicional como la capsulotomía con láser o membranectomía quirúrgica. El implante del lente intraocular a temprana edad se relacionó con buenos resultados quirúrgicos: mejoría de la agudeza visual corregida, presentándose el astigmatismo como el error refractivo más frecuente. La complicación transoperatorio y postoperatoria más frecuente fue la membrana inflamatoria, mientras que la complicación posoperatoria más frecuente fue la opacidad de la cápsula posterior.This paper described the results of the intraocular lens implantation performed in children, who had been seen at the Pediatric Ophthalmologic Service of " Ramon Pando Ferrer " Cuban Institute of Ophthalmology and had been diagnosed as having cataract of various etiologies, from April 2002 to April 2005. They were all followed-up for a year. Some parameters like the patient’s age, the etiology of cataract, visual acuity, pre-operative and post-operative refractive defect were considered in our study. The dioptric power of the most common intraocular lens and the most frequent complications during and after surgery were identified. The patients requiring additional treatment such as laser capsulotomy and surgical

  2. Antimicrobial activity of poly(acrylic acid) block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  3. Antimicrobial activity of poly(acrylic acid) block copolymers

    International Nuclear Information System (INIS)

    Gratzl, Günther; Paulik, Christian; Hild, Sabine; Guggenbichler, Josef P.; Lackner, Maximilian

    2014-01-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed

  4. New acrylic resin composite with improved thermal diffusivity.

    Science.gov (United States)

    Messersmith, P B; Obrez, A; Lindberg, S

    1998-03-01

    Studies have shown that physical characteristics of denture base materials may affect patient acceptance of denture prostheses by altering sensory experience of food during mastication. Thermal diffusivity is one material property that has been cited as being important in determining gustatory response, with denture base acrylic resins having low thermal diffusivity compared with denture base metal alloys. This study prepared and characterized experimental acrylic resin composite material with increased thermal diffusivity. Sapphire (Al2O3) whiskers were added to conventional denture base acrylic resin during processing to achieve loadings of 9.35% and 15% by volume. Cylindrical test specimens containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 degree to 70 degrees C). Thermal diffusivities of the sapphire containing composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the volume percentage of sapphire filler, which suggested that the high aspect ratio ceramic particles formed a pathway for heat conduction through the insulating polymer matrix. The thermal diffusivity of denture base acrylic resin was increased by the addition of thermally conducting sapphire whiskers.

  5. UV-crosslinkable photoreactive self-adhesive hydrogels based on acrylics

    Directory of Open Access Journals (Sweden)

    Czech Zbigniew

    2016-06-01

    Full Text Available Hydrogels are a unique class of macromolecular networks that can hold a large fraction of an aqueous solvent within their structure. They are suitable for biomedical area including controlled drug delivery and for technical applications as self-adhesive materials for bonding of wet surfaces. This paper describes photoreactive self-adhesive hydrogels based on acrylics crosslinked using UV radiation. They are prepared in ethyl acetate through radical polymerization of monomers mixture containing 2-ethylhexyl acrylate (2-EHA, butyl acrylate (BA, acrylic acid (AA and copolymerizable photoinitiator 4-acryloyloxy benzophenone (ABP at presence of radical starter 2.2’-azobis-diisobutyronitrile AIBN. The synthesized acrylic copolymers were determined by viscosity and GPC analysis and later modified using ethoxylated amines. 4-acryloyloxy benzophenone (ABP was used as crosslinking monomer. After UV crosslinking the properties of these novel synthesized hydrogels, such as tack, peel adhesion, shears strength, elongation and water adsorption were also studied.

  6. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  7. Artificial saliva effect on toxic substances release from acrylic resins

    Directory of Open Access Journals (Sweden)

    Kostić Milena

    2015-01-01

    Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

  8. Planck 2015 results. XV. Gravitational lensing

    CERN Document Server

    Ade, P.A.R.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J.M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P.B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P.M.; Macías-Pérez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P.G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Nørgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G.W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J.P.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; White, M.; Yvon, D.; Zacchei, A.

    2016-01-01

    We present the most significant measurement of the cosmic microwave background (CMB) lensing potential to date (at a level of 40 sigma), using temperature and polarization data from the Planck 2015 full-mission release. Using a polarization-only estimator we detect lensing at a significance of 5 sigma. We cross-check the accuracy of our measurement using the wide frequency coverage and complementarity of the temperature and polarization measurements. Public products based on this measurement include an estimate of the lensing potential over approximately 70% of the sky, an estimate of the lensing potential power spectrum in bandpowers for the multipole range 40lensing potential power spectrum and that found in the best-fitting LCDM model based on the Planck temperature and polarization power spectra. Using the lensing likelihood alone we obtain a percent-level measurement of ...

  9. Gravitational lensing of quasars

    CERN Document Server

    Eigenbrod, Alexander

    2013-01-01

    The universe, in all its richness, diversity and complexity, is populated by a myriad of intriguing celestial objects. Among the most exotic of them are gravitationally lensed quasars. A quasar is an extremely bright nucleus of a galaxy, and when such an object is gravitationally lensed, multiple images of the quasar are produced – this phenomenon of cosmic mirage can provide invaluable insights on burning questions, such as the nature of dark matter and dark energy. After presenting the basics of modern cosmology, the book describes active galactic nuclei, the theory of gravitational lensing, and presents a particular numerical technique to improve the resolution of astronomical data. The book then enters the heart of the subject with the description of important applications of gravitational lensing of quasars, such as the measurement of the famous Hubble constant, the determination of the dark matter distribution in galaxies, and the observation of the mysterious inner parts of quasars with much higher r...

  10. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Science.gov (United States)

    2013-09-11

    ..., 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium, ammonium..., hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium...

  11. The development of epoxidised palm oil acrylate (EPOLA) and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, Mohd Hilmi [Nuclear Energy Unit, Bangi, Selangor (Malaysia)

    1994-12-31

    The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets).

  12. The development of epoxidised palm oil acrylate (EPOLA) and its applications

    International Nuclear Information System (INIS)

    Mohd Hilmi Mahmood

    1993-01-01

    The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets)

  13. Transient anterior subcapsular vacuolar change of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation.

    Science.gov (United States)

    Chung, Jin Kwon; Shin, Jin Hee; Lee, Sung Jin

    2013-10-25

    We present two cases of transient vacuolar changes in the anterior subcapsular space of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation. Implantable collamer lenses (ICL) were implanted in healthy myopic patients. Vacuolar changes developed just after the irrigating procedure through the narrow space between the ICL and the crystalline lens. Slit-lamp examinations and spectral domain optical coherence tomography showed bleb-like lesions in the anterior subcapsular space of one eye in each case, though the lesions gradually improved without visual deterioration. Consequently, the lesions turned into a few anterior subcapsular small faint opacities. Direct irrigation of the narrow space confined by the ICL and the crystalline lens is at risk for the development of vacuolar changes in the crystalline lens. The observed spontaneous reversal indicates that surgeons should not rush to surgical intervention but rather opt for close follow over several weeks.

  14. Photochemistry of acrylates at 222 nm

    International Nuclear Information System (INIS)

    Knolle, Wolfgang; Naumov, Sergej; Madani, Mohamed; Sonntag, Clemens von

    2005-01-01

    Excimer lamps as monochromatic UV sources with an intense short-wavelength emission (especially KrCl * , 222 nm) allow a photoinitiator-free initiation of the acrylate polymerisation. Laser photolysis (KrCl * excimer laser, pulse width 20 ns, up to 5 mJ per pulse) gives rise to similar transient spectra (λ max ∼ 280 nm) for all acrylates studied. As the rather unspecific spectra do not allow conclusions as to the main reaction channel, a product study has been performed by GC-MS following steady-state photolysis of acrylate solutions in acetonitrile, methanol and n-hexane. Somewhat unexpected, α-cleavage seems to be a main reaction channel, and quantum chemical calculations show that such a reaction can occur from either the excited singlet state or the unrelaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented

  15. KINOFORM LENSES - TOWARD NANOMETER RESOLUTION.

    Energy Technology Data Exchange (ETDEWEB)

    STEIN, A.; EVANS-LUTTERODT, K.; TAYLOR, A.

    2004-10-23

    While hard x-rays have wavelengths in the nanometer and sub-nanometer range, the ability to focus them is limited by the quality of sources and optics, and not by the wavelength. A few options, including reflective (mirrors), diffractive (zone plates) and refractive (CRL's) are available, each with their own limitations. Here we present our work with kinoform lenses which are refractive lenses with all material causing redundant 2{pi} phase shifts removed to reduce the absorption problems inherently limiting the resolution of refractive lenses. By stacking kinoform lenses together, the effective numerical aperture, and thus the focusing resolution, can be increased. The present status of kinoform lens fabrication and testing at Brookhaven is presented as well as future plans toward achieving nanometer resolution.

  16. The effect of intraocular gas and fluid volumes on intraocular pressure.

    Science.gov (United States)

    Simone, J N; Whitacre, M M

    1990-02-01

    Large increases in the intraocular pressure (IOP) of postoperative gas-containing eyes may require the removal of gas or fluid to reduce the IOP to the normal range. Application of the ideal gas law to Friedenwald's equation provides a mathematical model of the relationship between IOP, intraocular gas and fluid volumes, and the coefficient of scleral rigidity. This mathematic model shows that removal of a given volume of gas or fluid produces an identical decrease in IOP and that the more gas an eye contains, the greater the volume reduction necessary to reduce the pressure. Application of the model shows that the effective coefficient of scleral rigidity is low (mean K, 0.0021) in eyes with elevated IOP that have undergone vitrectomy and retinal cryopexy and very low (mean K, 0.0013) in eyes with elevated IOP that have undergone placement of a scleral buckle and band. By using the appropriate mean coefficient of rigidity, the volume of material to be aspirated to produce a given decrease in IOP can be predicted with clinically useful accuracy.

  17. Commercial air travel after intraocular gas injection.

    Science.gov (United States)

    Houston, Stephen; Graf, Jürgen; Sharkey, James

    2012-08-01

    Passengers with intraocular gas are at risk of profound visual loss when exposed to reduced absolute pressure within the cabin of a typical commercial airliner. Information provided on the websites of the world's 10 largest airlines offer a considerable range of opinion as to when it might be safe to fly after gas injection. Physicians responsible for clearing pseassengers as 'fit to fly' should be aware modern retinal surgical techniques increasingly employ long-acting gases as vitreous substitutes. The kinetics of long-acting intraocular gases must be considered when deciding how long after surgery it is safe to travel. It is standard practice to advise passengers not to fly in aircraft until the gas is fully resorbed. To achieve this, it may be necessary to delay travel for approximately 2 wk after intraocular injection of sulfur hexafluoride (SF6) and for 6 wk after injection of perfluoropropane (C3F8).

  18. Correlating optical bench performance with clinical defocus curves in varifocal and trifocal intraocular lenses.

    Science.gov (United States)

    Plaza-Puche, Ana B; Alió, Jorge L; MacRae, Scott; Zheleznyak, Len; Sala, Esperanza; Yoon, Geunyoung

    2015-05-01

    To investigate the correlations existing between a trifocal intraocular lens (IOL) and a varifocal IOL using the "ex vivo" optical bench through-focus image quality analysis and the clinical visual performance in real patients by study of the defocus curves. This prospective, consecutive, nonrandomized, comparative study included a total of 64 eyes of 42 patients. Three groups of eyes were differentiated according to the IOL implanted: 22 eyes implanted with the varifocal Lentis Mplus LS-313 IOL (Oculentis GmbH, Berlin, Germany); 22 eyes implanted with the trifocal FineVision IOL (Physiol, Liege, Belgium), and 20 eyes implanted with the monofocal Acrysof SA60AT IOL (Alcon Laboratories, Inc., Fort Worth, TX). Visual outcomes and defocus curve were evaluated postoperatively. Optical bench through-focus performance was quantified by computing an image quality metric and the cross-correlation coefficient between an unaberrated reference image and captured retinal images from a model eye with a 3.0-mm artificial pupil. Statistically significant differences among defocus curves of different IOLs were detected for the levels of defocus from -4.00 to -1.00 diopters (D) (P < .01). Significant correlations were found between the optical bench image quality metric results and logMAR visual acuity scale in all groups (Lentis Mplus group: r = -0.97, P < .01; FineVision group: r = -0.82, P < .01; Acrys of group: r = -0.99, P < .01). Linear predicting models were obtained. Significant correlations were found between logMAR visual acuity and image quality metric for the multifocal and monofocal IOLs analyzed. This finding enables surgeons to predict visual outcomes from the optical bench analysis. Copyright 2015, SLACK Incorporated.

  19. Pigment dispersion and Artisan phakic intraocular lenses: crystalline lens rise as a safety criterion.

    Science.gov (United States)

    Baïkoff, Georges; Bourgeon, Grégoire; Jodai, Horacio Jitsuo; Fontaine, Aline; Lellis, Fernando Viera; Trinquet, Laure

    2005-04-01

    To validate the theory that crystalline lens rise can be used as a safety criterion to prevent pigment dispersion in eyes with an Artisan phakic intraocular lens (IOL) (Ophtec BV). Monticelli Clinic, Marseilles, France. A comparative analysis of crystalline lens rise in 9 eyes with pigment dispersion and 78 eyes without dispersion was performed. All eyes had previous implantation of an Artisan IOL. Anterior segment imaging was done using an anterior chamber optical coherence tomography (AC OCT) prototype. Crystalline lens rise was defined by the distance between the anterior pole of the crystalline lens and the horizontal plane joining the opposite iridocorneal recesses. The study confirmed that crystalline lens rise can be considered a safety criterion for implantation of Artisan-type phakic IOLs. The higher the crystalline lens rise, the greater the risk for developing pigment dispersion in the area of the pupil. This complication occurred more frequently in hyperopic eyes than in myopic eyes. Results indicate there is little or no risk for pigment dispersion if the rise is less than 600 microm; 67% of eyes with a rise of 600 microm or more developed pupillary pigment dispersion. In some cases in which the IOL was loosely fixated, there was no traction on the iris root and dispersion was prevented or delayed. Crystalline lens rise should be considered a new safety criterion for Artisan phakic IOL implantation and should also be applied to other types of phakic IOLs. The distance remaining between the crystalline lens rise and a 600 microm theoretical safety level allows one to calculate how long the IOL can safely remain in the eye.

  20. Synthesis and characterization of acrylated Parkia biglobosa medium oil alkyds

    Directory of Open Access Journals (Sweden)

    E.T. Akintayo

    2004-12-01

    Full Text Available Acrylated Parkia biglobosa medium oil alkyd prepared by the reaction between an acid containing acrylic copolymer and a monoglyceride followed by the addition of polyol and dibasic acid has been investigated for improved properties. The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum levels for modification of alkyds with such copolymers beyond which certain film properties are adversely affected.

  1. Efectividad de los lentes fáquicos Artisan en la corrección de la alta miopía Effectiveness of Artisan phakic lenses in the correction of high myopia

    Directory of Open Access Journals (Sweden)

    Yanele Ruiz Rodríguez

    2010-12-01

    Full Text Available OBJETIVO: Determinar la efectividad de los lentes intraoculares fáquicos Artisan en la corrección de la alta miopía en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" en el período de enero del 2006 a enero del 2009. MÉTODOS: Se realizó un estudio prospectivo, descriptivo. El universo estuvo constituido por el total de ojos (120 a los cuales se les implantó estos lentes. RESULTADOS: Se encontró un componente esférico de 0,5, no astigmatismo inducido y una mejoría de la agudeza visual corregida de 0,9. No se presentaron complicaciones transoperatorias y entre las posoperatorias mediatas predominó la iritis o uveítis (3,4 % así como la atrofia iridiana (5 % entre las tardías. CONCLUSIONES: Los resultados refractivos fueron favorables. Predominaron los pacientes sin complicaciones.OBJECTIVE: To determine the effectiveness of Artisan phakic intraocular lenses in correcting high myopia at "Ramón Pando Ferrer" Cuban Institute of Ophthalmology in January 2006 to January 2009 period. METHODS: A prospective descriptive study was made in which the universe of study was 120 eyes implanted with this type of lenses. RESULTS: Spheral component of 0.5; the induced astigmatism was not found and the corrected visual acuity improvement was 0.9. There were no transoperative complications; the predominant postoperative mediate complications were iritis or uveitis (3.4 % and iridic atrophy (5 % prevailed in the late ones. CONCLUSIONS: The refractive results were favourable. The uncomplicated patients predominated.

  2. Galaxy–Galaxy Weak-lensing Measurements from SDSS. I. Image Processing and Lensing Signals

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wentao [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China); Yang, Xiaohu; Zhang, Jun; Tweed, Dylan [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Fu, Liping; Shu, Chenggang [Shanghai Key Lab for Astrophysics, Shanghai Normal University, 100 Guilin Road, 200234, Shanghai (China); Mo, H. J. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Bosch, Frank C. van den [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Li, Ran [Key Laboratory for Computational Astrophysics, Partner Group of the Max Planck Institute for Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Li, Nan [Department of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Liu, Xiangkun; Pan, Chuzhong [Department of Astronomy, Peking University, Beijing 100871 (China); Wang, Yiran [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States); Radovich, Mario, E-mail: walt@shao.ac.cn, E-mail: xyang@sjtu.edu.cn [INAF-Osservatorio Astronomico di Napoli, via Moiariello 16, I-80131 Napoli (Italy)

    2017-02-10

    We present our image processing pipeline that corrects the systematics introduced by the point-spread function (PSF). Using this pipeline, we processed Sloan Digital Sky Survey (SDSS) DR7 imaging data in r band and generated a galaxy catalog containing the shape information. Based on our shape measurements of the galaxy images from SDSS DR7, we extract the galaxy–galaxy (GG) lensing signals around foreground spectroscopic galaxies binned in different luminosities and stellar masses. We estimated the systematics, e.g., selection bias, PSF reconstruction bias, PSF dilution bias, shear responsivity bias, and noise rectification bias, which in total is between −9.1% and 20.8% at 2 σ levels. The overall GG lensing signals we measured are in good agreement with Mandelbaum et al. The reduced χ {sup 2} between the two measurements in different luminosity bins are from 0.43 to 0.83. Larger reduced χ {sup 2} from 0.60 to 1.87 are seen for different stellar mass bins, which is mainly caused by the different stellar mass estimator. The results in this paper with higher signal-to-noise ratio are due to the larger survey area than SDSS DR4, confirming that more luminous/massive galaxies bear stronger GG lensing signals. We divide the foreground galaxies into red/blue and star-forming/quenched subsamples and measure their GG lensing signals. We find that, at a specific stellar mass/luminosity, the red/quenched galaxies have stronger GG lensing signals than their counterparts, especially at large radii. These GG lensing signals can be used to probe the galaxy–halo mass relations and their environmental dependences in the halo occupation or conditional luminosity function framework.

  3. All-acrylic superelastomers: facile synthesis and exceptional mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei; Goodwin, Andrew; Wang, Yangyang; Yin, Panchao; Wang, Weiyu; Zhu, Jiahua; Wu, Ting; Lu, Xinyi; Hu, Bin; Hong, Kunlun; Kang, Nam-Goo; Mays, Jimmy (Tennessee-K); (ORNL)

    2018-01-01

    All-acrylic multigraft copolymers made by a facile synthesis procedure exhibit elongation at break >1700% and strain recovery behavior far exceeding those of commercial acrylic and styrenic triblock copolymers.

  4. Intraocular Inflammation Associated with Ocular Toxoplasmosis : Relationships at Initial Examination

    NARCIS (Netherlands)

    Dodds, Emilio M.; Holland, Gary N.; Stanford, Miles R.; Yu, Fei; Siu, Willie O.; Shah, Kayur H.; Loon, Ninette Ten Dam-Van; Muccioli, Cristina; Hovakimyan, Anna; Barisani-Asenbauer, Talin

    2008-01-01

    PURPOSE: To describe characteristics of intraocular inflammation in eyes with active ocular toxoplasmosis and to identify relationships between signs of inflammation, complications (including elevated intraocular pressure [IOP]), other disease features, and host characteristics. DESIGN: Multicenter,

  5. Thermogravimetric analysis of the polymer acrylate-vinyl ether mixture cured by radiation

    International Nuclear Information System (INIS)

    Danu, Sugiarto

    1998-01-01

    An experiment on thermal stability of the polymer acrylate-vinyl ether mixture cured by radiation have been done using thermogravimetric analysis. Three kinds of acrylic oligomers i.e., epoxy acrylate, urethane acrylate, and polypropylene glycol diacrylate, and vinyl ether monomers i.e., triethylene glycol divinyl ether (DVE-3), 1,4-cyclohexane dimethanol divinyl ether (CHVE), and butanediol monovinyl ether (HBVE) were used in the experiment. Reaction was taken via radical and cationic polymerisation. In case of cationic polymerisation, diphenyliodonium hexafluorophosphate fotoinisiator was used in the formulation. Thermogravimetric analysis was conducted in a nitrogen atmosphere at a flow rate of 40 ml/minute with a constant heating rate 10 o C and evaluation range were done from 25 to 500 o C. The results of thermogravimetric analysis showed that acrylate and DVE-3 mixture produced the polymer films with higher thermal stability than the mixture of acrylate with CHVE or HBVE. The composition of acrylate-vinyl ether mixture and degree of unsaturation of vinyl ether monomers influenced the thermal stability of polymer. The mixture of epoxy acrylate-vinyl ether and polypropylene glycol diacrylate-vinyl ether have 1 initial decomposition temperature whereas the urethane acrylate-vinyl ether mixture has 2 initial decomposition temperatures. (authors)

  6. Long-Chain Diacrylate Crosslinkers and Use of PEG Crosslinks in Poly(potassium acrylate-acrylic acid)/Kaolin Composite Superabsorbents

    OpenAIRE

    Koroush Kabiri; Siavash Nafisi; Mohammad jalaledin Zohuriaan-Mehr; Ali Akbar Yousefi

    2013-01-01

    Long-chain diacrylate crosslinkers based on linear α,ω-diols were synthesized and characterized using FTIR and 1H NMR spectroscopy. The highest reaction yield (99.5%) was due to polyethylene glycol diacrylate 1000 (PEGDA-1000). Then, kaolin-containing poly(potassium acrylate-acrylic acid) superabsorbent composites and kaolin-free counterparts were synthesized using PEGDA-1000.The effect of the crosslinker concentration on swelling, rheological and thermo-mechanical properties was investigated...

  7. Microbial adhesion to silicone hydrogel lenses: a review.

    Science.gov (United States)

    Willcox, Mark D P

    2013-01-01

    Microbial adhesion to contact lenses is believed to be one of the initiating events in the formation of many corneal infiltrative events, including microbial keratitis, that occur during contact lens wear. The advent of silicone hydrogel lenses has not reduced the incidence of these events. This may partly be related to the ability of microbes to adhere to these lenses. The aim of this study was to review the published literature on microbial adhesion to contact lenses, focusing on adhesion to silicone hydrogel lenses. The literature on microbial adhesion to contact lenses was searched, along with associated literature on adverse events that occur during contact lens wear. Particular reference was paid to the years 1995 through 2012 because this encompasses the time when the first clinical trials of silicone hydrogel lenses were reported, and their commercial availability and the publication of epidemiology studies on adverse events were studied. In vitro studies of bacterial adhesion to unworn silicone hydrogel lens have shown that generally, bacteria adhere to these lenses in greater numbers than to the hydroxyethyl methacrylate-based soft lenses. Lens wear has different effects on microbial adhesion, and this is dependent on the type of lens and microbial species/genera that is studied. Biofilms that can be formed on any lens type tend to protect the bacteria and fungi from the effects on disinfectants. Fungal hyphae can penetrate the surface of most types of lenses. Acanthamoeba adhere in greater numbers to first-generation silicone hydrogel lenses compared with the second-generation or hydroxyethyl methacrylate-based soft lenses. Microbial adhesion to silicone hydrogel lenses occurs and is associated with the production of corneal infiltrative events during lens wear.

  8. Adhesion of Pseudomonas aeruginosa to orthokeratology and alignment lenses.

    Science.gov (United States)

    Choo, Jennifer D; Holden, Brien A; Papas, Eric B; Willcox, Mark D P

    2009-02-01

    To determine whether contact lenses designed for orthokeratology (OK) are colonized by greater numbers of bacteria compared with standard (alignment fitted) design rigid gas permeable lenses before and after lens wear. Eighteen 1-year-old cats were randomly fitted with an OK lens in one eye and an alignment fitted (AF) lens in the other eye. Both lenses were made in the same diameter and central thickness and of the same material. Two separate wearing periods of 2 weeks and 6 weeks were used. After each wearing period, lenses were soaked in Pseudomonas aeruginosa (6294 or 6206) for 10 min. The lenses were then reinserted onto their respective corneas for a wearing period of 16 hours after which lenses were collected and remaining adhered bacteria quantified. Unworn control lenses were also soaked and bacteria enumerated for comparison. There were no significant differences in the number of bacteria adherent to unworn AF and OK lenses. Analysis of lenses after wear showed OK lenses retained significantly higher numbers of viable bacteria than AF lenses in all studies. OK lenses retain more bacteria than AF rigid gas permeable lenses after bacteria-loaded overnight lens wear. This may increase the risk for an infection in OK patients should suitable conditions be present. Specific education on the cleaning of OK lenses is essential.

  9. One Episode, Two Lenses

    Science.gov (United States)

    Drijvers, Paul; Godino, Juan D.; Font, Vicenc; Trouche, Luc

    2013-01-01

    A deep understanding of students' learning processes is one of the core challenges of research in mathematics education. To achieve this, different theoretical lenses are available. The question is how these different lenses compare and contrast, and how they can be coordinated and combined to provide a more comprehensive view on the topic of…

  10. Effect of plasma colloid osmotic pressure on intraocular pressure during haemodialysis

    OpenAIRE

    Tokuyama, T.; Ikeda, T.; Sato, K.

    1998-01-01

    BACKGROUND—In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after haemodialysis is evaluated.
METHODS—Intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight were evaluated before a...

  11. Solutions for care of silicone hydrogel lenses.

    Science.gov (United States)

    Willcox, Mark D P

    2013-01-01

    During wear of contact lenses on a daily wear basis, it is necessary to disinfect the lens overnight before reinserting the lens the next day. The ability of the solutions used for this to disinfect lenses and lens cases is important for safe lens wear. The literature on the disinfecting ability of multipurpose disinfecting solutions (MPDS) commonly used with silicone hydrogel lenses reported during the period 2000 to 2012 is reviewed, as this is the period of time during which these lenses have been commercially available. Particular emphasis is placed on the ability of disinfecting solutions to control colonization of lens cases by microbes and changes in composition and use of the solutions. In addition, the literature is reviewed on ways of minimizing lens case microbial contamination. Maintaining the hygiene of contact lenses and lens cases is important in minimizing various forms of corneal infiltrative events that occur during lens wear. Although lens case contamination is not associated with different lenses, it is determined by use of different MPDS. MPDS that allow more frequent or heavy contamination of cases by Gram-negative bacteria are associated with a higher incidence of corneal infiltrative events. MPDS are now available that contain dual disinfectants. Wiping lens cases with tissues or using lens cases that incorporate silver are associated with reductions in contamination in clinical trials. Similarly, using MPDS to rub and rinse lenses before disinfection may reduce levels of microbes on lenses. The MPDS also contain surfactants that help reduce deposition and denaturation of proteins on lenses. Improvements in MPDS formulations and hygiene practices may help to reduce the incidence of adverse events that are seen during use with silicone hydrogel lenses.

  12. Weak lensing of the Lyman α forest

    Science.gov (United States)

    Croft, Rupert A. C.; Romeo, Alessandro; Metcalf, R. Benton

    2018-06-01

    The angular positions of quasars are deflected by the gravitational lensing effect of foreground matter. The Lyman α (Lyα) forest seen in the spectra of these quasars is therefore also lensed. We propose that the signature of weak gravitational lensing of the Lyα forest could be measured using similar techniques that have been applied to the lensed cosmic microwave background (CMB), and which have also been proposed for application to spectral data from 21-cm radio telescopes. As with 21-cm data, the forest has the advantage of spectral information, potentially yielding many lensed `slices' at different redshifts. We perform an illustrative idealized test, generating a high-resolution angular grid of quasars (of order arcminute separation), and lensing the Lyα forest spectra at redshifts z = 2-3 using a foreground density field. We find that standard quadratic estimators can be used to reconstruct images of the foreground mass distribution at z ˜ 1. There currently exists a wealth of Lyα forest data from quasar and galaxy spectral surveys, with smaller sightline separations expected in the future. Lyα forest lensing is sensitive to the foreground mass distribution at redshifts intermediate between CMB lensing and galaxy shear, and avoids the difficulties of shape measurement associated with the latter. With further refinement and application of mass reconstruction techniques, weak gravitational lensing of the high-redshift Lyα forest may become a useful new cosmological probe.

  13. Achromatic X-ray lenses

    International Nuclear Information System (INIS)

    Umbach, Marion

    2009-01-01

    This thesis presents first results on the development of achromatic refractive X-ray lenses which can be used for scientific experiments at synchrotron sources. First of all the different requirements for achromatic X-ray lenses have been worked out. There are different types of lenses, one type can be used for monochromatized sources when the energy is scanned while the spot size should be constant. The other type can be used at beamlines providing a broad energy band. By a combination of focusing and defocusing elements we have developed a lens system that strongly reduces the chromatic aberration of a refractive lens in a given energy range. The great challenge in the X-ray case - in contrast to the visible range - the complex refractive index, which is very similar for the possible materials in the X-ray spectrum. For precise studies a numerical code has been developed, which calculates the different rays on their way through the lenses to the detector plane via raytracing. In this numerical code the intensity distribution in the detector plane has been analyzed for a chromatic and the corresponding achromatic system. By optimization routines for the two different fields of applications specific parameter combinations were found. For the experimental verification an achromatic system has been developed, consisting of biconcave SU-8 lenses and biconvex Nickel Fresnel lenses. Their fabrication was based on the LIGA-process, including a further innovative development, namely the fabrication of two different materials on one wafer. In the experiment at the synchrotron source ANKA the energy was varied in a specific energy range in steps of 0.1 keV. The intensity distribution for the different energies was detected at a certain focal length. For the achromatic system a reduction of the chromatic aberration could be clearly shown. Achromatic refractive X-ray lenses, especially for the use at synchrotron sources, have not been developed so far. As a consequence of the

  14. Adherence of Pseudomonas aeruginosa to contact lenses

    International Nuclear Information System (INIS)

    Miller, M.J.

    1988-01-01

    The purpose of this research was to examined the interactions of P. aeruginosa with hydrogel contact lenses and other substrata, and characterize adherence to lenses under various physiological and physicochemical conditions. Isolates adhered to polystyrene, glass, and hydrogel lenses. With certain lens types, radiolabeled cells showed decreased adherence with increasing water content of the lenses, however, this correlation with not found for all lenses. Adherence to rigid gas permeable lenses was markedly greater than adherence to hydrogels. Best adherence occurred near pH 7 and at a sodium chloride concentration of 50 mM. Passive adhesion of heat-killed cells to hydrogels was lower than the adherence obtained of viable cells. Adherence to hydrogels was enhanced by mucin, lactoferrin, lysozyme, IgA, bovine serum albumin, and a mixture of these macromolecules. Adherence to coated and uncoated lenses was greater with a daily-wear hydrogel when compared with an extended-wear hydrogel of similar polymer composition. Greater adherence was attributed to a higher concentration of adsorbed macromolecules on the 45% water-content lens in comparison to the 55% water-content lens

  15. Severe pigment dispersion after iris-claw phakic intraocular lens implantation.

    Science.gov (United States)

    Galvis, Virgilio; Carreño, Néstor I; Tello, Alejandro; Laiton, Andrea N

    2017-12-01

    A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

  16. Severe pigment dispersion after iris-claw phakic intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Virgilio Galvis

    2017-01-01

    Full Text Available A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

  17. Treatment of dystrophic calcification on a silicone intraocular lens with pars plana vitrectomy

    Directory of Open Access Journals (Sweden)

    Mehta N

    2014-07-01

    Full Text Available Nitish Mehta,1 Roger A Goldberg,2 Chirag P Shah21University of Massachusetts Medical School, Worcester, MA, USA; 2Department of Retina, Ophthalmic Consultants of Boston, Boston, Massachusetts, USAPurpose: Dense, vision-obscuring calcification on the posterior aspect of silicone intraocular lenses (IOLs is often not amenable to neodymium:yttrium-aluminum-garnet capsulotomy, and, in prior reports, has required IOL exchange. We report the successful removal of dense calcium deposition on the posterior surface of a three-piece silicone lens using pars plana vitrectomy (PPV.Materials and methods: A 23-gauge PPV was performed using the Stellaris® vitrectomy system. A light pipe was used to retroilluminate the IOL, and a dense fibrous tissue setting with a low cut-rate and high aspiration rate was able to clear the visual axis of the dystrophic calcification without damaging the IOL optic.Results: Visual acuity improved from 20/100 to 20/25.Conclusion: Small-gauge PPV may be utilized to remove dense dystrophic calcium deposits on the lens surface in lieu of IOL exchange. Keywords: cataract surgery, technique, Nd:YAG capsulotomy, IOL exchange

  18. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  19. Comparison of posterior capsule folds following intracapsular implantation of three types of intraocular lenses with different haptic design

    Directory of Open Access Journals (Sweden)

    Ling-Lin Zhang

    2018-04-01

    Full Text Available AIM: To compare the incidence of posterior capsule folds among different types of intraocular lens(IOLto determine risk factors of posterior capsule folds. METHODS:It was a retrospective study. We collected the cases in which the patients underwent phacoemulsification(PHACOand IOL implantation and at least one of the three types of IOL was implanted, including 2-haptic 3-piece IOLs(HOYA PY60AD, 4-haptic 1-piece IOLs(Bausch & Lomb AO, 2-haptic 1-piece IOLs(AMO Tecnis ZCB00. The posterior capsule folds were measured using slit lamp microscope 2d after the surgery. Information of patient's age, gender, length of ocular axis, intraocular pressure, types of IOL were recorded. Posterior capsule fold risk indicators were identified by using logistic regression analysis. RESULTS: One hundred eighty-seven patients(242 eyeshad been collected, including 80 eyes implanted with HOYA PY60AD IOLs, 81 eyes implanted with Bausch & Lomb AO IOLs, 81 eyes implanted with AMO Tecnis ZCB00 IOLs. The incidence of posterior capsule folds of patients implanted with HOYA PY60AD IOLs was significantly higher than those of patients implanted with AMO Tecnis ZCB00 IOLs(56.3% vs 38.3%, P=0.027. While the incidence of patients implanted with Bausch & Lomb AO IOLs was significantly lower than those of patients implanted with AMO Tecnis ZCB00 IOLs(14.8% vs 38.3%, P=0.001. Multi-factor logistics regression analysis demonstrated that independent risk factors were type of IOLs and length of ocular axis. Compared with AMO Tecnis ZCB00 IOLs, using HOYA PY60AD IOLs increased the risk of posterior capsule folds \\〖P=0.020, OR(95%CI=2.145(1.129,4.073\\〗, while using Bausch & Lomb AO IOLs reduced the risk \\〖P=0.001, OR(95%CI=0.274(0.127, 0.591\\〗. Shorter ocular axis might increase the risk of posterior capsule folds \\〖P=0.012, OR(95%CI=0.669(0.489, 0.915\\〗. CONCLUSION: Haptic design should be an important consideration in IOL design. Compared with AMO Tecnis ZCB00 IOLs

  20. Microbial adherence to cosmetic contact lenses.

    Science.gov (United States)

    Chan, Ka Yin; Cho, Pauline; Boost, Maureen

    2014-08-01

    To investigate whether cosmetic contact lenses (CCL) with surface pigments affect microbial adherence. Fifteen brands of CCL were purchased from optical, non-optical retail outlets, and via the Internet. A standardized rub-off test was performed on each CCL (five lenses per brand) to confirm the location of the pigments. The rub-off test comprised gentle rubbing on the surfaces of each CCL with wetted cotton buds for a maximum of 20 rubs per surface. A new set of CCL (five lenses per brand) were incubated in Pseudomonas aeruginosa overnight. Viable counts of adhered bacteria were determined by the number of colony-forming units (CFU) on agar media on each lens. The adherence of P. aeruginosa as well as Staphylococcus aureus and Serratia marcescens to three brands of CCL (A-C) (five lenses per brand) were also compared to their adherences on their clear counterparts. Only two of the 15 brands of CCL tested (brands B and C) had pigments that did not detach with the rub-off test. The remaining 13 brands of CCL all failed the rub-off test and these lenses showed higher P. aeruginosa adherence (8.7 × 10(5)-1.9 × 10(6) CFU/lens). Brands B and C lenses showed at least six times less bacterial adhesion than the other 13 brands. Compared to their clear counterparts, bacterial adherence to brands B and C lenses did not differ significantly, whereas brand A lenses showed significantly higher adherence. Surface pigments on CCL resulted in significantly higher bacterial adherence. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  1. The sensitizing capacity of multifunctional acrylates in the guinea pig.

    Science.gov (United States)

    Björkner, B

    1984-10-01

    The multifunctional acrylates used in ultraviolet (UV) curable resins act as cross-linkers and "diluents". They are usually based on di(meth)acrylate esters of dialcohols or tri- and tetra-acrylate esters of polyalcohols. In UV-curable coatings, the most commonly used are pentaerythritol triacrylate (PETA), trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA). In other uses, such as dental composite resin materials, the dimethacrylic monomers based on n-ethylene glycol are the most useful. The sensitizing capacity of various multifunctional acrylates and their cross-reactivity pattern have been investigated with the guinea pig maximization test. The tests show that BUDA (1,4-butanediol diacrylate) and HDDA are moderate to strong sensitizers and that they probably cross-react with each other. The n-ethylene glycol diacrylates and methacrylates tested are weak or non-sensitizers. Tripropylene glycol diacrylate (TPGDA) is a moderate and neopentyl glycol diacrylate (NPGDA) a strong sensitizer, whereas neopentyl glycol dimethacrylate is a non-sensitizer. The commercial PETA is a mixture of pentaerythritol tri- and tetra-acrylate (PETA-3 and PETA-4). PETA-3 is a much stronger sensitizer than PETA-4. Simultaneous reactions were seen between PETA-3, PETA-4 and TMPTA. The oligotriacrylate OTA 480 is a moderate sensitizer, but no concomitant reactions were seen with PETA-3, PETA-4 or TMPTA. Of the multifunctional acrylates tested, the di- and triacrylic compounds should be regarded as potent sensitizers. The methacrylated multifunctional acrylic compounds are weak or non-sensitizers.

  2. UV-Curing of Nanoparticle Reinforced Acrylates

    International Nuclear Information System (INIS)

    Bauer, F.

    2006-01-01

    Polymer reinforcement by silica and alumina nanoparticles evidently yields improved surface hardness. Single mixing of nanoparticles into an acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification providing an interface between the two dissimilar materials. For example, vinyltrimethoxysilane (VTMO) can react via hydrolysis/condensation reactions with hydroxyl groups present on the inorganic surface and should bond via the polymerisation-active vinyl group to an acrylate resin through crosslinking reactions. Grafting reactions of surface OH groups and different trialkoxysilanes were studied by thermogravimetry, infrared, and multinuclear NMR spectroscopy. The copolymeri-zation of modified nanoparticles with the acrylate matrix has been investigated by 13 C NMR spectroscopy. UV curing under nitrogen inertization revealed a lower reactivity of vinyl groups of VTMO-modified silica compared to grafted methacryloxypropyl-trimethoxysilane (MEMO) which showed complete conversion of olefinic carbons (signals at 120 - 140 ppm). Under conditions of oxygen inhibition, the effect of the kind and the concentration of photoinitiator on the photopoly-merization reaction was studied. Compared to neat polyacrylate coatings the nanocomposite materials exhibit markedly improved properties, e.g., heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nano-particles and corundum microparticles. In particular cases, radiation curing with 172 nm photons generated by Xe excimer was performed to obtain structured polymer surfaces, i.e., matting of the reinforced acrylate coatings

  3. Fundus autofluorescence patterns in primary intraocular lymphoma.

    Science.gov (United States)

    Casady, Megan; Faia, Lisa; Nazemzadeh, Maryam; Nussenblatt, Robert; Chan, Chi-Chao; Sen, H Nida

    2014-02-01

    To evaluate fundus autofluorescence (FAF) patterns in patients with primary intraocular (vitreoretinal) lymphoma. Records of all patients with primary intraocular lymphoma who underwent FAF imaging at the National Eye Institute were reviewed. Fundus autofluorescence patterns were evaluated with respect to clinical disease status and the findings on fluorescein angiography and spectral-domain optical coherence tomography. There were 18 eyes (10 patients) with primary intraocular lymphoma that underwent FAF imaging. Abnormal autofluorescence in the form of granular hyperautofluorescence and hypoautofluorescence was seen in 11 eyes (61%), and blockage by mass lesion was seen in 2 eyes (11%). All eyes with granular pattern on FAF had active primary intraocular lymphoma at the time of imaging, but there were 5 eyes with unremarkable FAF, which were found to have active lymphoma. The most common pattern on fluorescein angiography was hypofluorescent round spots with a "leopard spot" appearance (43%). These hypofluorescent spots on fluorescein angiography correlated with hyperautofluorescent spots on FAF in 5 eyes (36%) (inversion of FAF). Nodular hyperreflective spots at the level of retinal pigment epithelium on optical coherence tomography were noted in 43% of eyes. The hyperautofluorescent spots on FAF correlated with nodular hyperreflective spots on optical coherence tomography in 6 eyes (43%). Granularity on FAF was associated with active lymphoma in majority of the cases. An inversion of FAF (hyperautofluorescent spots on FAF corresponding to hypofluorescent spots on fluorescein angiography) was observed in less than half of the eyes.

  4. WHAT HAPPENS TO INTRAOCULAR PRESSURE AFTER PERIBULBAR ANAESTHESIA?

    Directory of Open Access Journals (Sweden)

    Krishnamoorthy Segharipuram Ranganathan

    2017-08-01

    Full Text Available BACKGROUND Most of intraocular surgeries are done under local anaesthesia. The peribulbar anaesthesia provides adequate anaesthesia and akinesia. There is no reported intraoperative and/or postoperative amaurosis. The peribulbar anaesthesia provides adequate anaesthesia and akinesia. The disadvantages of it are the larger quantity of the aesthetic agent. Increasing the bulk load on the globe and a reported rise of intraocular pressure. MATERIALS AND METHODS A study of fifty cases was conducted in patients who received peribulbar anaesthesia undergoing cataract extraction with intraocular lens implantation and their intraocular pressures were noted and studied after giving the peribulbar anaesthesia all given by the same surgeon. RESULTS This study did show that the peribulbar anaesthesia increases the intraocular pressure in all the cases. The external ocular compression indeed helps to dissipate the anaesthetic load thereby reducing the enormous rise in IOP, which is only expected if you recollect the fact that the eyeball occupies one sixth of the total volume of the orbit that is 5 mL and 30 mL. The volume of peribulbar anaesthesia (6 mL does add its effects to increase the IOP. Hence, a properly planned post peribulbar compression helps to minimise the transient rise in IOP. CONCLUSION Summarising the study, it is better to give peribulbar injection initially followed by external ocular compression after a delay of at least 2 to 5 minutes. It is also advised that an initial compression maybe given in slightly risk cases, so that the peribulbarinduced rise may not be alarming. The anaesthetic solution maybe fragmented and the second injection maybe delayed by 5 minutes or omitted if good akinesia and anaesthesia are achieved already.

  5. (Meth)Acrylate Occupational Contact Dermatitis in Nail Salon Workers: A Case Series.

    Science.gov (United States)

    DeKoven, Samuel; DeKoven, Joel; Holness, D Linn

    Recently, many cases of acrylate-associated allergic contact dermatitis have appeared among nail salon workers. Common acrylate-containing products in nail salons include traditional nail polish, ultraviolet-cured shellac nail polish, ultraviolet-cured gel nails, and press-on acrylic nails. Nail salon technicians seen in the occupational medicine clinic in 2015 and 2016 were identified, and their patch test results and clinical features were summarized. Patch testing was done with the Chemotechnique (Meth)Acrylate nail series, and either the North American Standard series or the North American Contact Dermatitis Group screening series. Six patients were identified, all women, ages 38 to 58. Common presentations included erythematous dermatitis of the dorsa of the hands, palms, and forearms and fissures on the fingertips. Less common sites of eruptions included the periorbital region, cheeks, posterior ears, neck, sacral area, lateral thighs, and dorsa of the feet. All patients reacted to hydroxyethyl methacrylate, and 5 patients reacted to ethyl acrylate. Each patient also reacted to (meth)acrylates that are not found on either standard series, including ethyleneglycol dimethacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxyethyl acrylate. The authors report 6 cases of allergic contact dermatitis to acrylates in nail technicians seen over the past year, representing a new trend in their clinic. These cases are reflective of a growing trend of nail technicians with allergic contact dermatitis associated with occupational (meth)acrylate exposure. Efforts to improve prevention are needed.

  6. [Contact dermatitis caused by acrylates among 8 workers in an elevator factory].

    Science.gov (United States)

    Pérez-Formoso, J L; de Anca-Fernández, J; Maraví-Cecilia, R; Díaz-Torres, J M

    2010-05-01

    Acrylates are widely used low-molecular-weight substances, initially introduced in industry in the 1930s and subsequently applied also in medicine and the home. One of their main features is the ability to undergo polymerization. The most commonly used acrylic compounds are cyanoacrylates, methacrylates, and acrylates. To confirm suspicion of occupational disease in a group of workers in an elevator factory. We studied 8 patients with dermatitis of the hands and finger pads. In their work, the patients came into contact with acrylates. Patch testing was applied with an acrylate panel (BIAL-Aristegui, Bilbao, Spain). Seven of the patients (87. 5%) had a positive result with 1% ethylene glycol dimethacrylate. Positive were also observed for 2% hydroxyethyl methacrylate (5 patients, 62. 5%), 1% triethylene glycol dimethacrylate (4 patients, 50%), 10% ethyl methacrylate monomer (3 patients, 37. 5%), 10% methyl methacrylate monomer (2 patients, 25%), 1% ethyl acrylate (1 patient, 12. 5%), and 0. 1% acrylic acid (1 patient, 12. 5%). We highlight the strong sensitizing capacity of acrylates and the importance of taking all necessary preventive measures in industries where these substances are used. Such measures should include avoidance of contact with the product in cases where sensitization has been confirmed.

  7. Analysis and Testing of Bisphenol A-Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    OpenAIRE

    Jahanshahi , Shayesteh; Pizzi , Antonio; Abdulkhani , Ali; Shakeri , Alireza

    2016-01-01

    International audience; A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET) and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, C-13-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 degrees C for 12 h. FT-MIR, C-13...

  8. Visual outcome with the Oculentis Mplus intraocular lens

    OpenAIRE

    Si-Yuan Liu; Xu Yang

    2017-01-01

    AIM: To evaluate the visual outcome of Oculentis Mplus intraocular lens(IOL).METHODS: Totally 20 eyes in 20 patients received phacoemulsification and Oculentis Mplus intraocular lens implantation were as test group, and 20 eyes(Aspira-aA IOL)were as control group. The following postoperative examinations were performed after operation for 3mo: uncorrected visual acuity of distance and near, refractive results, UBM examination, the rate of wearing spectacles and the complications. RESULTS: At ...

  9. In-the-bag capsular tension ring and intraocular lens subluxation or dislocation: a series of 23 cases.

    Science.gov (United States)

    Werner, Liliana; Zaugg, Brian; Neuhann, Tobias; Burrow, Michael; Tetz, Manfred

    2012-02-01

    To describe clinical and pathologic findings from cases of in-the-bag capsular tension ring (CTR) and intraocular lens (IOL) subluxation or dislocation. Retrospective case series with clinicopathologic correlation. Twenty-three explanted subluxated/dislocated capsular bags containing a CTR and an IOL explanted in Europe and submitted in fixative to the Berlin Eye Research Institute. Standard gross and light microscopy of specimens, complete histopathologic analyses of selected specimens done at the University of Utah, as well as questionnaire sent to explanting surgeons, and patient chart review, when available. Lens design, material, and abnormalities, capsular bag anomalies, patient demographic data, surgical dates, and presence or absence of known risk factors. Patients were aged 76.31 ± 8.24 years at explantation, which was performed 81.5 ± 32.2 months after implantation. The IOLs in these cases were 3-piece hydrophobic acrylic (N = 11), 1-piece hydrophobic acrylic (n = 6), 3-piece silicone (n = 4), or 1-piece hydrophilic acrylic (n = 2) designs; all CTRs were made of poly(methyl methacrylate). Available information on associated ocular conditions included pseudoexfoliation (n = 17), glaucoma (n = 4), vitrectomy/retina surgery (n = 3), and trauma (n = 1). Complete histopathologic assessment in 3 specimens showed signs consistent with pseudoexfoliation, without available history related to this condition in one of the cases. Moderate/severe degrees of Soemmering's ring formation and capsulorhexis phimosis were observed or reported in 13 and 11 specimens, respectively. Fourteen eyes were implanted and explanted by the same surgeon, with an interval of 92.7 ± 23.4 months between the procedures. His rate of explantation because of subluxation/dislocation was 0.76% of the CTRs implanted during the time considered. Explantation because of postoperative subluxation or dislocation of CTR-IOL-capsular bag complexes occurred approximately 6.8 years after implantation

  10. In vitro cytotoxicity of self-curing acrylic resins of different colors

    Directory of Open Access Journals (Sweden)

    Luciana Borges Retamoso

    2014-08-01

    Full Text Available OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6 according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil: Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+, a glass specimen (C- and cell control (CC. Specimens were immersed in Minimum Eagle's Medium (MEM and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA with a 492-nm wavelength λ=492 nm. RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

  11. Efeito do filtro de ultravioleta em lentes de contato hidrofílicas de alta hidratação Ultraviolet filter effect on hydrophilic high hydrated contact lenses

    Directory of Open Access Journals (Sweden)

    Arlindo José Freire Portes

    2008-06-01

    Full Text Available A exposição à radiação ultravioleta está relacionada ao aparecimento de patologias oculares como ceratites, cataratas, degenerações maculares ou pterígio. Esta radiação está dividida em 3 tipos de acordo com o seu comprimento de onda: Uv-A (320-400nm, Uv-B (290-320nm e Uv-C (100-290nm. A indústria óptica desenvolveu filtros de ultravioleta para lentes intra-oculares, lentes de contato e lentes de óculos. OBJETIVO: Avaliar a eficácia do filtro de ultravioleta em lentes de contato de alta hidratação. MÉTODOS: Seis grupos de lentes de contato de alta hidratação e de marcas diferentes, contendo 3 unidades novas e iguais foram estudadas, observando-se o percentual de transmissão da energia luminosa de 200 a 400 nm através de um espectofotômetro. RESULTADOS: Os 3 grupos que apresentavam filtro de ultravioleta causaram uma queda abrupta na transmissão da radiação ultravioleta de 400 nm até 340 nm, ocorrendo um aumento na transmissão entre 240 a 300 nm até um nível máximo de 45%. Abaixo de 240 nm e entre 300 e 340 nm, houve um completo bloqueio da transmissão da radiação ultravioleta. Os 3 grupos que não apresentavam filtros de ultravioleta causaram uma queda abrupta na transmissão da radiação ultravioleta abaixo de 240 nm, ocorrendo um bloqueio completo de transmissão abaixo de 220 nm. CONCLUSÃO: As lentes de contato sem filtro Uv testadas não bloquearam com eficácia a radiação Uv-A, B ou C, e as com filtro bloquearam quase totalmente a radiação Uv-B e parcialmente a radiação Uv-A e Uv-C.The exposure to ultraviolet radiation is associated with the beginning of ocular pathologies like keratites, cataract, age-related macular degeneration and pterygium. This radiation is divided in 3 bands according to the wave length: Uv-A (320-400, Uv-B (290-320, Uv-C (100-290. The optic industry developed ultraviolet filters to intraocular lenses, contact lenses and spectacle lenses. PURPOSE: The issue of this work is

  12. Axial movement of the dual-optic accommodating intraocular lens for the correction of the presbyopia: Optical performance and clinical outcomes

    Directory of Open Access Journals (Sweden)

    Javier Tomás-Juan

    2015-04-01

    Full Text Available Presbyopia occurs in the aging eye due to changes in the ciliary muscle, zonular fibers, crystalline lens, and an increased lens sclerosis. As a consequence, the capacity of accommodation decreases, which hampers to focus near objects. With the aim of restoring near vision, different devices that produce multiple focuses have been developed and introduced. However, these devices are still unable to restore accommodation. In order to achieve that goal, dual-optic accommodating Intraocular Lenses have been designed, whose anterior optic displaces axially to increase ocular power, and focus near objects. Although dual-optic accommodating IOLs are relatively new, their outcomes are promising, as they provide large amplitudes of accommodation and a greater IOL displacement than single-optic accommodating IOLs. The outcomes show comfortable near vision, higher patients’ satisfaction rates, and minimal postoperative complications like Posterior Capsular Opacification and Anterior Capsular Opacification, due to their design and material.

  13. Clinical study on the incidence of vancomycin intraocular injection in treatment with suppurative endophthalmitis

    Directory of Open Access Journals (Sweden)

    Yi-Qin Duan

    2015-05-01

    Full Text Available AIM:To estimate the clinical significance of the microculture of humor and vitreous and vancomycin intraocular injection in treatment of suppurative endophthalmitis associated with intraocular foreign bodies.METHODS: Totally 65 patients with penetrating eye trauma and retained intraocular foreign bodies in emergency operation and intraocular injection from January 2012 to September 2014 were regarded as the study group, another 62 patients with penetrating eye trauma and retained intraocular foreign bodies in emergency operation without intraocular injection before August 2011 were regarded as the control group. Aqueous humor and vitreous humor were taken from each patient of the study group and the control group for bacteria and fungus cultivation. The study group was treated with 1mg vancomycin intraocular injection after operation, while the control group was not. RESULTS: The incidence of endophthalmitis in the control group was 16%(10 cases, while in the study group was 3%(2 cases, with significant difference between two groups(x2=6.32, PP>0.05. The positive rate of vitreous humor germiculture in study group was 14%(9 cases, and the incidence of endophthalmitis was 3%. The positive rate of vitreous humor germiculture in control group was 11%(7 casesand the incidence of endophthalmitis was 16%, with significant differences between two groups(PCONCLUSION: Intraocular foreign bodies treated with emergency operation and vancomycin intraocular injections can decrease the incidence of suppurative endophthalmitis and have a good vision prognosis for the second stage of operation.

  14. Intraocular lens alignment from purkinje and Scheimpflug imaging.

    Science.gov (United States)

    Rosales, Patricia; De Castro, Alberto; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2010-11-01

    The improved designs of intraocular lenses (IOLs) implanted during cataract surgery demand understanding of the possible effects of lens misalignment on optical performance. In this review, we describe the implementation, set-up and validation of two methods to measure in vivo tilt and decentration of IOLs, one based on Purkinje imaging and the other on Scheimpflug imaging. The Purkinje system images the reflections of an oblique collimated light source on the anterior cornea and anterior and posterior IOL surfaces and relies on the well supported assumption of the linearity of the Purkinje images with respect to IOL tilt and decentration. Scheimpflug imaging requires geometrical distortion correction and image processing techniques to retrieve the pupillary axis, IOL axis and pupil centre from the three-dimensional anterior segment image of the eye. Validation of the techniques using a physical eye model indicates that IOL tilt is estimated within an accuracy of 0.261 degree and decentration within 0.161 mm. Measurements on patients implanted with aspheric IOLs indicate that IOL tilt and decentration tend to be mirror symmetric between left and right eyes. The average tilt was 1.54 degrees and the average decentration was 0.21 mm. Simulated aberration patterns using custom models of the patients eyes, built using anatomical data of the anterior cornea and foveal position, the IOL geometry and the measured IOL tilt and decentration predict the experimental wave aberrations measured using laser ray tracing aberrometry on the same eyes. This reveals a relatively minor contribution of IOL tilt and decentration on the higher-order aberrations of the normal pseudophakic eye.

  15. Survey of Intraocular Antibiotics Prophylaxis Practice after Open Globe Injury in China.

    Directory of Open Access Journals (Sweden)

    Bingsheng Lou

    Full Text Available To elucidate the Chinese practice of intraocular antibiotics administration for prophylaxis after open globe injury.A cross-sectional questionnaire survey was performed online by scanning a Quickmark (QR code with smartphones at the 20th Chinese National Conference of Ocular Trauma in November 2014.A total of 153 (30.6% of all participators at the conference responded. Of the respondents, 20.9% were routinely administered with prophylactic intraocular injection of antibiotics at the conclusion of the primary eye repair, and 56.9% were used only in cases with high risk of endophthalmitis development. The intraocular route of delivery was mainly included with intracameral injection (47.9% and intravitreal injection (42.0%. Cephalosporins (53.8% and vancomycin (42.0% were the main choices of antibiotic agents, followed by fluoroquinolones (24.3%, and aminoglycosides (13.4%. Only 21.9% preferred a combination of two or more two drugs routinely. In addition, significantly more respondents from the referral eye hospital (92.7% replied using intraocular antibiotics injection for prophylaxis compared to those respondents from the primary hospital (69.4% (p = 0.001, Fisher's exact test.Intraocular antibiotics injection for post-traumatic endophthalmitis prophylaxis is widely used in China. However, the choice of antibiotic agents and the intraocular route of delivery vary. A well-designed clinical trial is needed to establish a standardized protocol of intraocular antibiotics administration for post-traumatic endophthalmitis prophylaxis.

  16. The evolution of palm oil acrylates within 20 years in Nuclear Malaysia

    International Nuclear Information System (INIS)

    Mek Zah Salleh; Rida Tajau; Nurul Huda Mudri

    2016-01-01

    Acrylated palm oil was synthesized from epoxidized palm oil (EPOP), in early 1989, through acrylation/methacrylation process at Radiation Technology Division laboratory. The acrylated products namely Epoxidized Palm Oil Acrylate/Methacrylate (EPOLA/ EPOMA), with the molecular weight around 2000-3000 g/mol, was found curable when subjected to UV or EB irradiations. Isocyanation of EPOLAs resulted in a resin called Palm Oil Based Urethane Acrylate (POBUA). POBUA possess certain advantages over EPOLA such as much higher molecular weight between 5000 to 20000 g/ mol, better curing speed, crosslinking density, higher abrasion resistance and also higher pendulum hardness. Hyper branched polyurethane acrylate (HBPUA) from palm oil oleic was synthesized by a three-step reaction in 2012. The reaction was confirmed by several analytical data; hydroxyl value (OHV), FTIR, GPC and NMR spectroscopy analyses. The thermal decomposition of HBPUA formulations shows good thermal stability up to 450 degree Celsius. (author)

  17. EDITORIAL: Focus on Gravitational Lensing

    Science.gov (United States)

    Jain, Bhuvnesh

    2007-11-01

    Gravitational lensing emerged as an observational field following the 1979 discovery of a doubly imaged quasar lensed by a foreground galaxy. In the 1980s and '90s dozens of other multiply imaged systems were observed, as well as time delay measurements, weak and strong lensing by galaxies and galaxy clusters, and the discovery of microlensing in our galaxy. The rapid pace of advances has continued into the new century. Lensing is currently one of best techniques for finding and mapping dark matter over a wide range of scales, and also addresses broader cosmological questions such as understanding the nature of dark energy. This focus issue of New Journal of Physics presents a snapshot of current research in some of the exciting areas of lensing. It provides an occasion to look back at the advances of the last decade and ahead to the potential of the coming years. Just about a decade ago, microlensing was discovered through the magnification of stars in our galaxy by invisible objects with masses between that of Jupiter and a tenth the mass of the Sun. Thus a new component of the mass of our galaxy, dubbed MACHOs, was established (though a diffuse, cold dark matter-like component is still needed to make up most of the galaxy mass). More recently, microlensing led to another exciting discovery—of extra-solar planets with masses ranging from about five times that of Earth to that of Neptune. We can expect many more planets to be discovered through ongoing surveys. Microlensing is the best technique for finding Earth mass planets, though it is not as productive overall as other methods and does not allow for follow up observations. Beyond planet hunting, microlensing has enabled us to observe previously inaccessible systems, ranging from the surfaces of other stars to the accretion disks around the black holes powering distant quasars. Galaxies and galaxy clusters at cosmological distances can produce dramatic lensing effects: multiple images of background galaxies

  18. Gauge-invariant formalism of cosmological weak lensing

    Science.gov (United States)

    Yoo, Jaiyul; Grimm, Nastassia; Mitsou, Ermis; Amara, Adam; Refregier, Alexandre

    2018-04-01

    We present the gauge-invariant formalism of cosmological weak lensing, accounting for all the relativistic effects due to the scalar, vector, and tensor perturbations at the linear order. While the light propagation is fully described by the geodesic equation, the relation of the photon wavevector to the physical quantities requires the specification of the frames, where they are defined. By constructing the local tetrad bases at the observer and the source positions, we clarify the relation of the weak lensing observables such as the convergence, the shear, and the rotation to the physical size and shape defined in the source rest-frame and the observed angle and redshift measured in the observer rest-frame. Compared to the standard lensing formalism, additional relativistic effects contribute to all the lensing observables. We explicitly verify the gauge-invariance of the lensing observables and compare our results to previous work. In particular, we demonstrate that even in the presence of the vector and tensor perturbations, the physical rotation of the lensing observables vanishes at the linear order, while the tetrad basis rotates along the light propagation compared to a FRW coordinate. Though the latter is often used as a probe of primordial gravitational waves, the rotation of the tetrad basis is indeed not a physical observable. We further clarify its relation to the E-B decomposition in weak lensing. Our formalism provides a transparent and comprehensive perspective of cosmological weak lensing.

  19. Weak lensing and dark energy

    International Nuclear Information System (INIS)

    Huterer, Dragan

    2002-01-01

    We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy

  20. Mean intraocular pressure in hypertensive adults

    International Nuclear Information System (INIS)

    Irum, S.; Malik, A.M.; Saeed, M.

    2015-01-01

    To determine the mean Intraocular Pressure (IOP) in already diagnosed adult hypertensive patients with different grades of hypertension. Study Design: Cross-sectional descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore, from March 2012 to Aug 2012. Patients and Methods: A total of 178 already diagnosed hypertensive patients were selected. A detailed history of ocular or systemic diseases was taken. Intraocular pressure was measured with help of Goldmann applanation tonometer. Three consecutive readings of IOP of each eye were taken at 30 minutes interval and mean calculated. Blood pressure was recorded in seated position from right upper arm, by mercury sphygmomanometer. Blood pressure measurements were determined by taking the mean value of three systolic and diastolic readings. Results: The results of intraocular pressure (IOP) between various grades of hypertension were determined. There was an increase in mean IOP with rise in blood pressure. The subjects with grade I hypertension showed a mean IOP of 13.95 ± 3.74 mmHg, while grade II and grade III hypertensive subjects had mean IOPs as 18.10 ± 3.32 and 20.21 ± 2.52 mmHg respectively. Conclusion: A higher value of mean IOP was found with increase in systolic and diastolic blood pressures. (author)

  1. Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique.

    Science.gov (United States)

    Canut Jordana, M Isabel; Pérez Formigó, Daniel; Abreu González, Rodrigo; Nadal Reus, Jeroni

    2010-11-11

    We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact. Complete ophthalmologic examination and optical coherence tomography (OCT) of the anterior segment were performed. Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control. Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.

  2. Investigations of Galaxy Clusters Using Gravitational Lensing

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Matthew P. [Northern Illinois Univ., DeKalb, IL (United States)

    2014-08-01

    In this dissertation, we discuss the properties of galaxy clusters that have been determined using strong and weak gravitational lensing. A galaxy cluster is a collection of galaxies that are bound together by the force of gravity, while gravitational lensing is the bending of light by gravity. Strong lensing is the formation of arcs or rings of light surrounding clusters and weak lensing is a change in the apparent shapes of many galaxies. In this work we examine the properties of several samples of galaxy clusters using gravitational lensing. In Chapter 1 we introduce astrophysical theory of galaxy clusters and gravitational lensing. In Chapter 2 we examine evidence from our data that galaxy clusters are more concentrated than cosmology would predict. In Chapter 3 we investigate whether our assumptions about the number of galaxies in our clusters was valid by examining new data. In Chapter 4 we describe a determination of a relationship between mass and number of galaxies in a cluster at higher redshift than has been found before. In Chapter 5 we describe a model of the mass distribution in one of the ten lensing systems discovered by our group at Fermilab. Finally in Chapter 6 we summarize our conclusions.

  3. Instrumental systematics and weak gravitational lensing

    International Nuclear Information System (INIS)

    Mandelbaum, R.

    2015-01-01

    We present a pedagogical review of the weak gravitational lensing measurement process and its connection to major scientific questions such as dark matter and dark energy. Then we describe common ways of parametrizing systematic errors and understanding how they affect weak lensing measurements. Finally, we discuss several instrumental systematics and how they fit into this context, and conclude with some future perspective on how progress can be made in understanding the impact of instrumental systematics on weak lensing measurements

  4. Foot clearance and variability in mono- and multifocal intraocular lens users during stair navigation.

    Science.gov (United States)

    Renz, Erik; Hackney, Madeleine; Hall, Courtney

    2016-01-01

    Intraocular lenses (IOLs) provide distance and near refraction and are becoming the standard for cataract surgery. Multifocal glasses increase variability of toe clearance in older adults navigating stairs and increase fall risk; however, little is known about the biomechanics of stair navigation in individuals with multifocal IOLs. This study compared clearance while ascending and descending stairs in individuals with monofocal versus multifocal IOLs. Eight participants with multifocal IOLs (4 men, 4 women; mean age = 66.5 yr, standard deviation [SD] = 6.26) and fifteen male participants with monofocal IOLs (mean age = 69.9 yr, SD = 6.9) underwent vision and mobility testing. Motion analysis recorded kinematic and custom software-calculated clearances in three-dimensional space. No significant differences were found between groups on minimum clearance or variability. Clearance differed for ascending versus descending stairs: the first step onto the stair had the greatest toe clearance during ascent, whereas the final step to the floor had the greatest heel clearance during descent. This preliminary study indicates that multifocal IOLs have similar biomechanic characteristics to monofocal IOLs. Given that step characteristics are related to fall risk, we can tentatively speculate that multifocal IOLs may carry no additional fall risk.

  5. Soft-contact-lenses-induced complications

    Directory of Open Access Journals (Sweden)

    Suvajac Gordana

    2008-01-01

    Full Text Available Background/Aim. Soft contact lenses occupy significant place in ophthalmology, both in the correction of refraction anomalies and in the treatment of many eye diseases. The number of patients that wear soft contact lenses for the purpose of correcting ametropia is constantly increasing. Due to the increasing number of wearers, the percentage of complications that can lead to serious eye damage and serious vision loss is also increasing. The aim of this study was to point out the most common complications related to soft contact lens use. Methods. In the period from 1995−2004 this prospective study included 510 patients wearing soft contact lenses for correcting ametropia. None of the patients wore contact lenses before and none suffered from any system or local diseases that could affected the development of eventual complications. The study took seven years with the patients who wore conventional lenses and three years with those who wore replacement contact lenses. All the necessary ophthalmologic examinations were done (visual acuity, refractokeratometry, the quantity of tear film, biomicroscopic examination of anterior eye segment. All the complications were filmed by video camera. Results. Of all the patients, 19 had blepharitis, 73 suffered from “dry eye”, 57 had conjunctival hyperemia, 12 had conjunctivitis, 34 had gigantopapillary conjunctivitis (GPC, 93 had punctiform epitheliopathy, 20 had corneal infiltration, one patient had keratitis, 91 had corneal vascularisation, and 95 patients had corneal deposits. Conclusion. Both the type and frequency of complications related to soft contact lens use in our group of patients, proved to be significant. Some of this complications (keratitis can significantly damage vision and lead to loss of vision and sometimes can require operative treatment.

  6. Comparison of visual function and patient satisfaction with AcrySof ReSTORSN6AD1 multifocal intraocular compared to monofocal intraocular lenses 5

    Directory of Open Access Journals (Sweden)

    Aisa S Alchinova

    2016-12-01

    Full Text Available Aim. To compare visual function and satisfaction in patients after implantation of AcrySof ReSTOR SN6AD1 multifocal intraocular lens (IOL, AcrySof SA60AТ spherical monofocal IOL, or Akreos АО aspheric monofocal IOL during cataract surgery. Materials. Overall, 34 patients received SN6AD1 multifocal (group 1, 48 eyes, 19 patients received Akreos АО monofocal aspheric (group 2, 30 eyes, and 13 patients received AcrySof SA60AТ monofocal spherical (group 3, 18 eyes IOL. Patients with multifocal IOL were closely matched for age, sex, and ocular findings with patients who had monofocal IOL implantation. Six months postoperatively, uncorrected/corrected distance visual acuity (UDVA/CDVA, uncorrected intermediate (60 cm and near (35 cm visual acuity (UNVA, defocus curve, contrast sensitivity, and a quality-of-life questionnaire were evaluated. Furthermore, independence from glasses and presence of optical phenomena were assessed. Results. Patients in group 2 had statistically significant increase in UDVA than that in group 1 (p = 0.037. There was no significant difference in the mean uncorrected intermediate and best corrected distance visual acuities between the groups. UNVA was better in group 1 than that in groups 2 and 3 (p < 0.0001. Photopic contrast sensitivity for high spatial frequencies was better in groups 2 and 3. Glare was reported in 5.9% of patients in group 1. Halos occurred in 32.4% of patients in group 1. No one reported undesirable visual symptoms in groups 2 and 3. Conclusion. Multifocal IOLs provided higher spectacle independence and satisfactory functional vision over a broad range of distances but were associated with increased subjective visual symptoms and reduced photopic contrast sensitivity for high spatial frequencies and distance visual quality compared with monofocal IOLs.

  7. Intraocular pressure variations during zygomatic fracture reduction and fixation: a clinical study.

    LENUS (Irish Health Repository)

    Murray, Dylan J

    2012-02-03

    BACKGROUND: The reduction of midface fractures has been associated with the rare but devastating complication of blindness. An increase in intraocular pressure is important in the mechanism of blindness in this setting. In this study, the authors assessed the intraocular pressure in patients who underwent zygomatic fracture reduction (with or without fixation). METHODS: Using applanation tonometry, 29 patients underwent intraocular pressure measurements before, during, and after fracture fixation. The contralateral pressures were measured and used as the control. RESULTS: There were 29 patients with a mean age of 35 years, and the mean time to surgery was 5 days. Preoperatively, all patients had normal intraocular pressures and normal visual acuity. All patients underwent a Gillies lift and 18 patients required open reduction and fixation of the frontozygomatic suture (n = 4) or the infraorbital margin (n = 2), and the remainder (n = 12) required fixation of both points. There was no statistically significant increase in the intraocular pressures following the reduction of uncomplicated zygomatic fractures. Statistically significant pressure reductions were noted immediately after reduction and fixation. CONCLUSIONS: The surgical reduction of uncomplicated zygomatic fractures has no adverse effect on the intraocular pressure. It is the authors\\' opinion that adjunctive measures to reduce the pressures are unnecessary.

  8. Topical tissue plasminogen activator appears ineffective for the clearance of intraocular fibrin.

    Science.gov (United States)

    Zwaan, J; Latimer, W B

    1998-06-01

    To determine the efficacy of topical tissue plasminogen activator (tPA) for the resolution of postoperative or inflammatory intraocular fibrinous exudates. Each treatment consisted of drops of 1 mg/ml tPA given 9 times 5 minutes apart. Records were reviewed and the results at 24 and 48 hours were recorded. Sixty-two patients had a total of 94 treatments. Fibrin exudates following intraocular surgery in 34 patients were treated 44 times. In 6 patients there was a positive result. Fibrin associated with intraocular infection was treated in 9 patients. None showed clear improvement. Nineteen patients had a total of 34 treatments for poorly controlled intraocular pressure (IOP) after glaucoma surgery. Five patients showed adequate control of the IOP, 12 did not change, and 2 had a questionable improvement. Eleven patients had adequate IOP control after additional treatment. Seven required suture lysis, 2 ab interno bleb revision, and 2 YAG capsulotomy or iridotomy to reduce the IOP to an acceptable level. Within the limits of this retrospective study and taking into account that fibrin may resolve spontaneously, it appears that topical tPA drops are not effective for the liquefaction of intraocular fibrin after surgery or in association with intraocular inflammation. They did not improve IOP control after glaucoma surgery.

  9. Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique

    Directory of Open Access Journals (Sweden)

    M Isabel Canut Jordana

    2010-11-01

    Full Text Available M Isabel Canut Jordana1, Daniel Pérez Formigó1, Rodrigo Abreu González2, Jeroni Nadal Reus11Barraquer Ophthalmology Centre, Barcelona, Spain; 2University Hospital of La Candelaria, Tenerife, SpainAims: We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact.Methods: Complete ophthalmologic examination and optical coherence tomography (OCT of the anterior segment were performed.Results: Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control.Conclusion: Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.Keywords: pigmentary glaucoma, intraocular lens, optical coherence tomography, laser

  10. Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant

    Directory of Open Access Journals (Sweden)

    Clara Ye

    2018-06-01

    Full Text Available Purpose: We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL (Visian ICL™, Staar Inc., Monrovia, CA implant that resulted in advanced visual field loss. Observations: A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Conclusions and importance: Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss. Keywords: Phakic intraocular lens, Intraocular collamer lens, Pigment dispersion, Glaucoma

  11. Assessment of intraocular foreign bodies by helical-CT multiplanar imaging

    International Nuclear Information System (INIS)

    Papadopoulos, A.; Fotinos, A.; Maniatis, V.; Kavadias, S.; Michaelides, A.; Avouri, M.; Kalamara, C.; Stringaris, K.

    2001-01-01

    The aim of this study was to examine the effectiveness of helical CT in the assessment of intraocular foreign bodies, evaluating two protocols with different collimation. We performed helical-CT studies in 30 patients. Fifteen patients were examined with 1.5-mm collimation and the other 15 patients with 3.0-mm collimation. All other imaging parameters were identical in both protocols. Multiplanar images were reconstructed. The examinations were reviewed for presence, localization and size of intraocular foreign bodies. We compare our results with the surgical data. We estimate the required examination time. In the first group (collimation 1.5 mm) an intraorbital foreign body was detected in 8 of 15 patients. In 3 of 8 patients an intraocular foreign body (all were metallic) was detected. In the second group (collimation 3.0 mm) an intraorbital foreign body was detected in 9 of 15 patients. In 8 of 9 patients an intraocular foreign body (all were metallic) was detected. Our results were confirmed by surgery in all cases. Examination time was 36 s in the first group and 18 s in the second group. Computed tomography should be considered the imaging modality of choice in the assessment of metallic intraocular foreign bodies and 3.0-mm collimation is optional, because of reduced examination time and radiation exposure. (orig.)

  12. A novel clinical sign in intraocular tuberculosis: Active chorioretinitis within chorioretinal atrophy

    OpenAIRE

    Avinash Pathengay; Bhavik Panchal; Himadri Choudhury; Soumyava Basu; Nidhi Relhan; Harry W. Flynn, Jr.

    2017-01-01

    Purpose: To report a novel clinical sign in patients with intraocular tuberculosis. The current study is an observational consecutive case series of patients diagnosed with intraocular tuberculosis managed at a tertiary eye care centre from June 1, 2012 to December 31, 2015. Observations: The diagnosis of intraocular tuberculosis was made in 6 patients based on ocular features suggestive of tuberculosis along with a positive tuberculin skin testing and chest X-ray consistent with tuberculo...

  13. Weakly oval electron lense

    International Nuclear Information System (INIS)

    Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.

    2001-01-01

    The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system

  14. Lenses matching of compound eye for target positioning

    Science.gov (United States)

    Guo, Fang; Zheng, Yan Pei; Wang, Keyi

    2012-10-01

    Compound eye, as a new imaging method with multi-lens for a large field of view, could complete target positioning and detection fastly, especially at close range. Therefore it could be applicated in the fields of military and medical treatment and aviation with vast market potential and development prospect. Yet the compound eye imaging method designed use three layer construction of multiple lens array arranged in a curved surface and refractive lens and imaging sensor of CMOS. In order to simplify process structure and increase the imaging area of every sub-eye, the imaging area of every eye is coved with the whole CMOS. Therefore, for several imaging point of one target, the corresponding lens of every imaging point is unkonown, and thus to identify. So an algorithm was put forward. Firstly, according to the Regular Geometry relationship of several adjacent lenses, data organization of seven lenses with a main lens was built. Subsequently, by the data organization, when one target was caught by several unknown lenses, we search every combined type of the received lenses. And for every combined type, two lenses were selected to combine and were used to calculate one three-dimensional (3D) coordinate of the target. If the 3D coordinates are same to the some combine type of the lenses numbers, in theory, the lenses and the imaging points are matched. So according to error of the 3D coordinates is calculated by the different seven lenses numbers combines, the unknown lenses could be distinguished. The experimental results show that the presented algorithm is feasible and can complete matching task for imaging points and corresponding lenses.

  15. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu

    2015-01-01

    This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

  16. Comparison of a new refractive multifocal intraocular lens with an inferior segmental near add and a diffractive multifocal intraocular lens.

    Science.gov (United States)

    Alio, Jorge L; Plaza-Puche, Ana B; Javaloy, Jaime; Ayala, María José; Moreno, Luis J; Piñero, David P

    2012-03-01

    To compare the visual acuity outcomes and ocular optical performance of eyes implanted with a multifocal refractive intraocular lens (IOL) with an inferior segmental near add or a diffractive multifocal IOL. Prospective, comparative, nonrandomized, consecutive case series. Eighty-three consecutive eyes of 45 patients (age range, 36-82 years) with cataract were divided into 2 groups: group A, 45 eyes implanted with Lentis Mplus LS-312 (Oculentis GmbH, Berlin, Germany); group B, 38 eyes implanted with diffractive IOL Acri.Lisa 366D (Zeiss, Oberkochen, Germany). All patients underwent phacoemulsification followed by IOL implantation in the capsular bag. Distance corrected, intermediate, and near with the distance correction visual acuity outcomes and contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively during a 3-month follow-up. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), corrected distance near and intermediate visual acuity (CDNVA), contrast sensitivity, intraocular aberrations, and defocus curve. A significant improvement in UDVA, CDVA, and UNVA was observed in both groups after surgery (P ≤ 0.04). Significantly better values of UNVA (P<0.01) and CDNVA (P<0.04) were found in group B. In the defocus curve, significantly better visual acuities were present in eyes in group A for intermediate vision levels of defocus (P ≤ 0.04). Significantly higher amounts of postoperative intraocular primary coma and spherical aberrations were found in group A (P<0.01). In addition, significantly better values were observed in photopic contrast sensitivity for high spatial frequencies in group A (P ≤ 0.04). The Lentis Mplus LS-312 and Acri.Lisa 366D IOLs are able to successfully restore visual function after cataract surgery. The Lentis Mplus LS-312 provided better intermediate vision and contrast sensitivity outcomes than the Acri.Lisa 366D. However, the

  17. Synthesis and characterization of waterborne polyurethane acrylate copolymers

    International Nuclear Information System (INIS)

    Sultan, Misbah; Bhatti, Haq Nawaz; Zuber, Mohammad; Barikani, Mehdi

    2013-01-01

    Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties

  18. Toughening epoxy acrylate with polyurethane acrylates and hyper-branched polyester in three dimensional printing

    Science.gov (United States)

    Fang, Chao; Li, Ning; Liu, Yang; Lu, Gang

    2018-05-01

    In order to improve the toughness of epoxy acrylate (EA) in three dimensional printing (3D-printing), bifunctional polyurethane acrylate (PUA) and trifunctional PUA were firstly blended with EA. The multi-indicators orthogonal experiment, designed with the indicators of tensile strength, elongation at break and impact strength, was used to find out the optimal formulation. Then, hyper-branched polyesters (HBPs) was added to improve the toughness of the photocurable system. The microstructures of the cured specimens were characterized by optical microscopy and scanning electron microscopy. By analyzing their mechanical properties and microstructures, it was revealed that the best addition amounts of HBP are 10 wt%. Results indicated that their toughness improved a lot comparing with pure EA. The changes of mechanical properties were characterized by DMA. The addition of HBP could cause a loss in stiffness, elasticity modulus and thermostability.

  19. Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    Directory of Open Access Journals (Sweden)

    Shayesteh Jahanshahi

    2016-04-01

    Full Text Available A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have confirmed that the resin has been prepared under these conditions. The joints bonded with this resin were tested for block shear strength. The results obtained indicated that the best strength performance was obtained by the bioepoxy-acrylate adhesive resin prepared at 95 °C for a 12-h reaction.

  20. INTRAOCULAR CORRECTION OF PRESBYOPIA BY MONOVISION IN PATIENTS WITH CATARACT AND CORNEAL ASTIGMATISM

    Directory of Open Access Journals (Sweden)

    E. I. Belikova

    2017-01-01

    Full Text Available Purpose: To evaluate the results of intraocular correction of presbyopia by monovision in patients with cataract and primary corneal astigmatism and conduct a comparative analysis of these outcomes with the results of binocular multifocal IOLs implantation. Patients and methods. There were 21 patients with bilateral cataract surgery performed using toric monofocal intraocular lenses (monovision group in the study. The indications for the operation were: 1 primary corneal astigmatism ≥ 1.0D in patients with cataract, 2 inability to conduct excimer laser correction. Reduction of spectacle dependence by monovision was discussed during preoperative conversation. The age of patients range from 32 to 65 years. Target refraction: Emetronopia on the dominant eye (DG and myopia at 1.0–2.0 D in the non-dominant eye (NDG. Evaluation included measurement of uncorrected visual acuity, refraction, stereopsis, contrast sensitivity and patient satisfaction. The results were compared with the outcomes of binocular multifocal Iols implantation in 22 patients (44 eyes. Results. The spherical component decreased from 3.39±2.63D to 0.34±0.24D, cylinder decreased from 3.05±1.47D to 0.44±0,35D (P <0.01 in the monovision group three months after surgery . The deviation from target refraction was 0.30±0.35D. The mean difference between postoperative refraction on the two eyes was 1.92±0.57D. Postoperative corrected visual acuity significantly exceeded preoperative parameters. In 18 patients (88% the stereoscopic visual acuity did not exceed 60 seconds and corresponded to the age norm, in 3 patients (12% it was at the level of 80–100 arc seconds. In patients with multifocal IOLs, the stereovision values were identical (Ferrer-Blasco T. et al, 2008. Conclusion. The monovision is an effective method of reducing dependence on additional correction in patients with cataract and corneal astigmatism. Refractive outcomes, binocular visual acuity, predictability and

  1. Electrochemical investigation on an acrylated thiophene

    Energy Technology Data Exchange (ETDEWEB)

    Hogervorst, A.C.R. (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Kock, T.J.J.M. (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Ruiter, B. de (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Waal, A. van der (TNO Plastics and Rubber Research Inst., Delft (Netherlands))

    1993-03-22

    The electrochemical behaviour of electropolymerized 2-(3-thienyl)ethyl acrylate (PAcrT) has been investigated, and compared to the behaviour of electropolymerized thiophene and 3-n-decylthiophene (PDT). The effect of electron beam irradiation on the electrochemical properties of these three polymers has been studied. It has been found that for PAcrT the oxidation wave shifts to higher potentials upon electron beam irradiation. For PDT a similar but smaller change occurs. We suggest that the shift of the oxidation wave of PAcrT is caused by cross-links, formed between the acrylate substituents, which fixate the main chain parts in twisted states and reduce the conjugation length. (orig.)

  2. Factors influencing bacterial adhesion to contact lenses.

    Science.gov (United States)

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The adhesion of this strain reaches maximum numbers within 1h in most in vitro studies and a biofilm has generally formed within 24 h of cells adhering to the lens surface. Physical and chemical properties of contact lens material affect bacterial adhesion. The water content of hydroxyethylmethacrylate (HEMA)-based lenses and their iconicity affect the ability of bacteria to adhere. The higher hydrophobicity of silicone hydrogel lenses compared to HEMA-based lenses has been implicated in the higher numbers of bacteria that can adhere to their surfaces. Lens wear has different effects on bacterial adhesion, partly due to differences between wearers, responses of bacterial strains and the ability of certain tear film proteins when bound to a lens surface to kill certain types of bacteria.

  3. [Evaluation of accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer].

    Science.gov (United States)

    Chen, X; Peng, D; Zhou, W; Zhong, Y

    1995-06-01

    To evaluate the accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer. 58 patients' (113 eyes) intraocular pressure were measured by Keeler, non-contact tonometer and R 900 Goldmann applanation tonometer and the results of measurement of intraocular pressure by the two kinds of tonometers were compared. The mean intraocular pressure measured by non-contact is 16.31 +/- 5.59 mmHg and 17.49 +/- 6.13 mmHg (1 mmHg = 0.1333 kPa) by Goldmann applanation tonometer, respectively. There was no statistical significance to be found (P > 0.05) between the two methods. By linear correlation and regression analysis, a positive correlation was found between the two methods (r = 0.8942, b = 0.8154). The handheld non-contact tonometer has the same accuracy and reliability of measurement of intraocular pressure comparing with Goldmann applanation tonometer, and it can be used in glaucoma clinic and screening.

  4. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    Directory of Open Access Journals (Sweden)

    Bojanić Vaso

    2010-01-01

    Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

  5. Dynamics of Fermat potentials in nonperturbative gravitational lensing

    International Nuclear Information System (INIS)

    Frittelli, Simonetta; Newman, Ezra T.

    2002-01-01

    We present a framework, based on the null-surface formulation of general relativity, for discussing the dynamics of Fermat potentials for gravitational lensing in a generic situation without approximations of any kind. Additionally, we derive two lens equations: one for the case of thick compact lenses and the other one for lensing by gravitational waves. These equations in principle generalize the astrophysical scheme for lensing by removing the thin-lens approximation while retaining the weak fields

  6. Preparations and applications in UV curing coatings of epoxy acrylates containing carboxyl

    International Nuclear Information System (INIS)

    Wu Yu Min

    1999-01-01

    This paper introduces preparations of epoxy acrylates containing carboxyl through the reactions of epoxy acrylates with butanedioic anhydride, pentanedioic anhydride, cis-butenedioic anhydride, phthalic anhydride, tetrabromophthalic anhydride and -tetrahydrophthalic anhydride. These epoxy acrylates containing carboxyl have been applied to UV-curing coatings and their effects on properties of UV-curing coatings have been studied

  7. Nanofocusing Parabolic Refractive X-Ray Lenses

    International Nuclear Information System (INIS)

    Schroer, C.G.; Kuhlmann, M.; Hunger, U.T.; Guenzler, T.F.; Kurapova, O.; Feste, S.; Lengeler, B.; Drakopoulos, M.; Somogyi, A.; Simionovici, A. S.; Snigirev, A.; Snigireva, I.

    2004-01-01

    Parabolic refractive x-ray lenses with short focal distance can generate intensive hard x-ray microbeams with lateral extensions in the 100nm range even at short distance from a synchrotron radiation source. We have fabricated planar parabolic lenses made of silicon that have a focal distance in the range of a few millimeters at hard x-ray energies. In a crossed geometry, two lenses were used to generate a microbeam with a lateral size of 330nm by 110nm at 25keV in a distance of 41.8m from the synchrotron radiation source. First microdiffraction and fluorescence microtomography experiments were carried out with these lenses. Using diamond as lens material, microbeams with lateral size down to 20nm and below are conceivable in the energy range from 10 to 100keV

  8. Do swimming goggles limit microbial contamination of contact lenses?

    Science.gov (United States)

    Wu, Yvonne T; Tran, Jess; Truong, Michelle; Harmis, Najat; Zhu, Hua; Stapleton, Fiona

    2011-04-01

    Wearing goggles over contact lenses while swimming is often recommended by eye care professionals. Limited data are available to assess this recommendation. The purpose of this study was to examine whether wearing goggles while swimming limits bacterial colonization on contact lenses and whether the type of lens worn affects contamination rates. Twenty-three subjects underwent two swimming sessions at an ocean (salt water) pool (Maroubra beach Rock Pool, Sydney, Australia). Silicone hydrogel (Ciba Focus Night and Day) or hydrogel lenses (Ciba Focus Daily) were inserted into subjects' eyes before 30 min of swimming sessions, and subjects used modified goggles to mimic goggled and non-goggled conditions. At the end of each session, lenses were collected for microbial investigation. Viable bacterial colonies were classified as gram positive and gram negative and enumerated. The level of bacterial colonization on contact lenses between goggled and non-goggled conditions and between the two lens materials were compared. The range of colony forming units recovered from goggled lenses were 0 to 930 compared with 0 to 1210 on non-goggled lenses. The majority of subjects (16/23) had more microorganisms in the non-goggled condition than when wearing goggles (p = 0.03). Gram negative organisms were found in three non-goggled lenses. No significant difference was shown in the number of bacteria isolated from silicone hydrogel and hydrogel lenses (p > 0.6) irrespective of wearing goggles. Water samples had consistently higher numbers of bacterial counts than those adhered to the lenses; however, no association was found between the number of bacteria in the water sample and those found on the contact lenses. Consistently, fewer bacterial colonies were found on the goggled contact lens, thus suggesting goggles offer some protection against bacterial colonization of contact lenses while swimming. These data would support the recommendation encouraging lens wearers to use goggles

  9. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    OpenAIRE

    Kannikar Kwanming; Pairote Klinpituksa; Wae-asae Waehamad

    2009-01-01

    Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR) was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR) prior obtained from LNR with formic...

  10. Flurbiprofen and intraocular pressure.

    Science.gov (United States)

    Gieser, D K; Hodapp, E; Goldberg, I; Kass, M A; Becker, B

    1981-07-01

    Systemic or topical administration of corticosteroids may produce a rise in intraocular pressure (IOP). Nonsteroidal anti-inflammatory drugs (NSAI drugs) are alternate therapy for ocular inflammatory disease. Flurbiprofen, a new NSAI drug, was tested in double-masked fashion to delineate its effect on IOP. Flurbiprofen did not alter IOP in known high corticosteroid responders nor did it block corticosteroid-induced ocular hypertension.

  11. Axial movement of the dual-optic accommodating intraocular lens for the correction of the presbyopia: optical performance and clinical outcomes.

    Science.gov (United States)

    Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane

    2015-01-01

    Presbyopia occurs in the aging eye due to changes in the ciliary muscle, zonular fibers, crystalline lens, and an increased lens sclerosis. As a consequence, the capacity of accommodation decreases, which hampers to focus near objects. With the aim of restoring near vision, different devices that produce multiple focuses have been developed and introduced. However, these devices are still unable to restore accommodation. In order to achieve that goal, dual-optic accommodating Intraocular Lenses have been designed, whose anterior optic displaces axially to increase ocular power, and focus near objects. Although dual-optic accommodating IOLs are relatively new, their outcomes are promising, as they provide large amplitudes of accommodation and a greater IOL displacement than single-optic accommodating IOLs. The outcomes show comfortable near vision, higher patients' satisfaction rates, and minimal postoperative complications like Posterior Capsular Opacification and Anterior Capsular Opacification, due to their design and material. Copyright © 2014. Published by Elsevier Espana.

  12. Using Strong Gravitational Lensing to Identify Fossil Group Progenitors

    Science.gov (United States)

    Johnson, Lucas E.; Irwin, Jimmy A.; White, Raymond E., III; Wong, Ka-Wah; Maksym, W. Peter; Dupke, Renato A.; Miller, Eric D.; Carrasco, Eleazar R.

    2018-04-01

    Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.

  13. Intraocular Telescopic System Design: Optical and Visual Simulation in a Human Eye Model.

    Science.gov (United States)

    Zoulinakis, Georgios; Ferrer-Blasco, Teresa

    2017-01-01

    Purpose. To design an intraocular telescopic system (ITS) for magnifying retinal image and to simulate its optical and visual performance after implantation in a human eye model. Methods. Design and simulation were carried out with a ray-tracing and optical design software. Two different ITS were designed, and their visual performance was simulated using the Liou-Brennan eye model. The difference between the ITS was their lenses' placement in the eye model and their powers. Ray tracing in both centered and decentered situations was carried out for both ITS while visual Strehl ratio (VSOTF) was computed using custom-made MATLAB code. Results. The results show that between 0.4 and 0.8 mm of decentration, the VSOTF does not change much either for far or near target distances. The image projection for these decentrations is in the parafoveal zone, and the quality of the image projected is quite similar. Conclusion. Both systems display similar quality while they differ in size; therefore, the choice between them would need to take into account specific parameters from the patient's eye. Quality does not change too much between 0.4 and 0.8 mm of decentration for either system which gives flexibility to the clinician to adjust decentration to avoid areas of retinal damage.

  14. Separating intrinsic alignment and galaxy-galaxy lensing

    International Nuclear Information System (INIS)

    Blazek, Jonathan; Seljak, Uroš; Mandelbaum, Rachel; Nakajima, Reiko

    2012-01-01

    The coherent physical alignment of galaxies is an important systematic for gravitational lensing studies as well as a probe of the physical mechanisms involved in galaxy formation and evolution. We develop a formalism for treating this intrinsic alignment (IA) in the context of galaxy-galaxy lensing and present an improved method for measuring IA contamination, which can arise when sources physically associated with the lens are placed behind the lens due to photometric redshift scatter. We apply the technique to recent Sloan Digital Sky Survey (SDSS) measurements of Luminous Red Galaxy lenses and typical ( ∼ L * ) source galaxies with photometric redshifts selected from the SDSS imaging data. Compared to previous measurements, this method has the advantage of being fully self-consistent in its treatment of the IA and lensing signals, solving for the two simultaneously. We find an IA signal consistent with zero, placing tight constraints on both the magnitude of the IA effect and its potential contamination to the lensing signal. While these constraints depend on source selection and redshift quality, the method can be applied to any measurement that uses photometric redshifts. We obtain a model-independent upper-limit of roughly 10% IA contamination for projected separations of r p ≈ 0.1–10 h −1 Mpc. With more stringent photo-z cuts and reasonable assumptions about the physics of intrinsic alignments, this upper limit is reduced to 1–2%. These limits are well below the statistical error of the current lensing measurements. Our results suggest that IA will not present intractable challenges to the next generation of galaxy-galaxy lensing experiments, and the methods presented here should continue to aid in our understanding of alignment processes and in the removal of IA from the lensing signal

  15. Experiencia con la lente intraocular RAYNER 620H Experience gained with the use of intraocular lens RAYNER 620 H

    Directory of Open Access Journals (Sweden)

    Juan Raúl Hernández Silva

    2008-06-01

    Full Text Available Un importante eslabón en el progreso alcanzado en la cirugía de cataratas, está fundamentado en el desarrollo industrial paralelo que ha ocurrido durante los últimos años con la introducción de nuevos modelos de lentes intraoculares, como el Rayner 620 H; el perfeccionamiento del instrumental quirúrgico, sistemas de aspiración e irrigación bimanual y bisturí con la medida exacta para colocar el inyector de la lente intraocular. La lente intraocular Rayner 620H significó un gran paso para la facoemulsificación y el control de la opacidad de la cápsula posterior posoperatoria por el diseño peculiar de su óptica y hápticos, que permiten un implante seguro, fácil y una incisión mínima. Se realizó un estudio prospectivo y descriptivo, cuyo universo de estudio fueron 28 ojos con diagnóstico de cataratas a los cuales se les realizó facoemulsificación con implante de lente intraocular Rayner 620 H, en el Centro de Microcirugía Ocular del Instituto Cubano de oftalmología "Ramón Pando Ferrer" en el período comprendido entre junio de 2006 a febrero de 2007. El grupo de edades donde se encontró el de mayor número de pacientes fue en el de más de 60 años. En todos los casos hubo un aumento significativo de la agudeza visual sin corrección y con ella, del preoperatorio al posoperatorio. Hubo un aumento del cilindro queratométrico del preoperatorio al posoperatorio, pero este fue mínimo La pérdida de células endoteliales fue baja del preoperatorio al posoperatorio, respectivamente. No hubo ninguna complicación durante la cirugía ni después de esta. Evaluamos como satisfactoria la efectividad del lente intraocular Rayner 620 H, por el aumento de la agudeza visual del paciente, el bajo astigmatismo inducido, mejoría del campo visual por confrontación, mínima pérdida de células endoteliales, y ausencia de complicaciones y de deslumbramiento posoperatorio en los pacientes.An important link in the advances made by the

  16. Technology and the use of acrylics for provisional dentine protection.

    Science.gov (United States)

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue.

  17. Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

    Science.gov (United States)

    Salih, Ashraf M; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md Zin Wan

    2015-08-04

    Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

  18. Intraocular pressure in very low birth weight preterm infants and its association with postconceptional age

    Directory of Open Access Journals (Sweden)

    Rodrigo L. Lindenmeyer

    2012-11-01

    Full Text Available OBJECTIVE: To evaluate intraocular pressure in very low birth weight preterm infants and correlate it with postconceptional age. METHODS: The intraocular pressure in a prospective cohort of very low birth weight premature infants (defined as a birth weight <1,500 g and gestational age <32 weeks admitted to Hospital de Clínicas de Porto Alegre , Brazil was evaluated weekly. The evaluated outcome was the variation in the intraocular pressure following changes in the postconceptional age (defined as the gestational age at birth plus the age in weeks at the time of examination in the weeks following preterm birth. Mixed-effects models were used for the statistical analysis to determine the intraocular pressure variation according to postconceptional age, and means and 10th and 90th percentiles were calculated for the intraocular pressure values. RESULTS: Fifty preterm infants with a mean gestational age of 29.7 ± 1.6 weeks and a mean birth weight of 1,127.7 ± 222.7 g were evaluated. The mean intraocular pressure for the entire cohort considering both eyes was 14.9 ± 4.5 mmHg, and 13.5% of all recorded intraocular pressure values were greater than 20 mmHg. The analysis revealed a mean reduction in the intraocular pressure of 0.29 mmHg for each increase in postconceptional age (p = 0.047; 95% CI: -0.58 to -0.0035. The mean intraocular pressure (P10-P90 decreased from 16.3 mmHg (10.5222.16 at 26.3 weeks to 13.1 mmHg (7.28-18.92 at 37.6 weeks of postconceptional age. CONCLUSIONS: The mean intraocular pressure in very low birth weight preterm infants was 14.9 ± 4.5 mmHg. This value decreased 0.29 mmHg per week as the postconceptional age increased.

  19. Intraocular manifestations of mycobacterium tuberculosis: A review of the literature

    Directory of Open Access Journals (Sweden)

    Lauren A. Dalvin

    2017-05-01

    Full Text Available Mycobacterium tuberculosis: is most commonly associated with pulmonary infection. However, tuberculosis (TB can also affect the eye. TB can affect nearly any tissue in the eye, and a high index of suspicion is required for accurate diagnosis, as many of the intraocular manifestations of TB can mimic other, more common diseases. Correct diagnosis is critical because systemic anti-tuberculosis treatment may be required, and vision loss or even loss of the affected eye can occur without proper treatment. Thus, it is important for ophthalmologists and infectious disease specialists to work together to accurately diagnose and treat intraocular TB. This article reports the various known presentations of intraocular TB and reviews important elements of diagnosis and treatment. Keywords: Mycobacterium, Tuberculosis, Choroidal granuloma, Retinal vasculitis

  20. Epithelial Downgrowth after Intraocular Surgery Treated with Intracameral 5-Fluorouracil

    Directory of Open Access Journals (Sweden)

    Nina Ni

    2015-01-01

    Full Text Available Purpose. To present the clinical and histopathologic correlation of two cases of epithelial downgrowth (EDG after prior intraocular surgery. Methods. Observational case reports. Results. We present two cases of EDG occurring after intraocular surgery. In both cases, after two anterior chamber injections of 5-fluorouracil (5FU, the area of EDG initially regressed. In Case 1, a limited area of EDG eventually recurred, and penetrating keratoplasty with cryotherapy was curative. In Case 2, subsequent corneal edema required Descemet-stripping automated endothelial keratoplasty, and the patient remained clinically free of EDG without further treatment. Conclusion. Intracameral 5FU may have a role in the treatment of EDG after intraocular surgery, though its precise utilization and impact remain to be defined.

  1. Enzyme-Catalyzed Synthesis of Saccharide Acrylate Monomers from Nonedible Biomass

    NARCIS (Netherlands)

    Kloosterman, Wouter M. J.; Brouwer, Sander; Loos, Katja

    Various cellulase preparations were found to catalyze the transglycosidation between cotton linters and 2-hydroxyethyl acrylate. The conversion and enzyme activity were found to be optimal in reaction mixtures that contained 5 vol% of the acrylate. The structures of the products were revealed by

  2. Comparison between intraocular pressure spikes with water loading and postural change.

    Science.gov (United States)

    Chong, Calum Wk; Wang, Sarah B; Jain, Neeranjali S; Bank, Cassandra S; Singh, Ravjit; Bank, Allan; Francis, Ian C; Agar, Ashish

    2016-12-01

    To compare the agreement between peak intraocular pressures measured through the water drinking test and the supine test, in patients with primary open angle glaucoma. Consecutive, prospective, blinded. Twenty-one patients from the Glaucoma Unit, Prince of Wales Hospital, Sydney, Australia. For the supine test, intraocular pressure was recorded immediately after the patient had lain down and at 20 and 40 min. At the second evaluation, intraocular pressure was measured in each patient after drinking 10 mL/kg body weight of water for the water drinking test. Again, all patients had their intraocular pressure measured at 20 and 40 min (t = 20 and t = 40, respectively). Patients were excluded from the study if they had pre-existing cardiac, renal or pulmonary complications or had concurrent ocular disease or an anatomical abnormality (including angle recession, peripheral anterior synechiae and developmental anomalies of the angle) that may have influenced intraocular pressure. Bland-Altman analysis. Bland-Altman analysis indicated an overall excellent agreement in terms of mean difference between methods (1.0, -1.0 and -0.90 mmHg, at 0, 20 and 40 min, respectively). Further, with the exception of t = 40, all measured time points had 95% confidence intervals within 6.5 mmHg of their mean difference on the Bland-Altman plot. There was close agreement between the intraocular pressure values of the supine test and water drinking test. However, as the water drinking test may be uncomfortable and potentially hazardous, there is potential that the supine test may be a safer and more comfortable alternative. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  3. Predicting gravitational lensing by stellar remnants

    Science.gov (United States)

    Harding, Alexander J.; Stefano, R. Di; Lépine, S.; Urama, J.; Pham, D.; Baker, C.

    2018-03-01

    Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper, we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, five black holes, and ≈35 000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here, we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With Hubble Space Telescope, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets.

  4. Factors influencing bacterial adhesion to contact lenses

    OpenAIRE

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The ...

  5. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    International Nuclear Information System (INIS)

    Rida Tajau; Nurulhuda Mohd Yunus; Mohd Hilmi Mahmood; Mek Zah Salleh; Nik Ghazali Nik Salleh

    2013-01-01

    Full-text: The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidized palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) for example EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80 %) than the palm oil based compounds (up to 70 %), where the different is around 10-15 %. The hardness property from this two type coatings can reached until 50 % at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newton's (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photo initiator give higher adhesion property and their also showed a higher glossiness property on the glass substrate compared to the coatings containing irgacure-819 photo initiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough. (author)

  6. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    International Nuclear Information System (INIS)

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd

    2014-01-01

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough

  7. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    Energy Technology Data Exchange (ETDEWEB)

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang, Selangor (Malaysia); Ibrahim, Mohammad Izzat [Faculty of Science, University of Malaya (UM), 50603 Kuala Lumpur (Malaysia); Yunus, Nurulhuda Mohd [Faculty of Science and Technology, National University Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2014-02-12

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  8. Lensing reconstruction from a patchwork of polarization maps

    International Nuclear Information System (INIS)

    Namikawa, Toshiya; Nagata, Ryo

    2014-01-01

    The lensing signals involved in CMB polarization maps have already been measured with ground-based experiments such as SPTpol and POLARBEAR, and would become important as a probe of cosmological and astrophysical issues in the near future. Sizes of polarization maps from ground-based experiments are, however, limited by contamination of long wavelength modes of observational noise. To further extract the lensing signals, we explore feasibility of measuring lensing signals from a collection of small sky maps each of which is observed separately by a ground-based large telescope, i.e., lensing reconstruction from a patchwork map of large sky coverage organized from small sky patches. We show that, although the B-mode power spectrum obtained from the patchwork map is biased due to baseline uncertainty, bias on the lensing potential would be negligible if the B-mode on scales larger than the blowup scale of 1/f noise is removed in the lensing reconstruction. As examples of cosmological applications, we also show 1) the cross-correlations between the reconstructed lensing potential and full-sky temperature/polarization maps from satellite missions such as PLANCK and LiteBIRD, and 2) the use of the reconstructed potential for delensing B-mode polarization of LiteBIRD observation

  9. A new device to noninvasively estimate the intraocular pressure produced during ocular compression

    Directory of Open Access Journals (Sweden)

    Korenfeld MS

    2016-01-01

    Full Text Available Michael S Korenfeld,1,2 David K Dueker3 1Comprehensive Eye Care, Ltd., 2Department of Ophthalmology and Visual Sciences, Washington University, Washington, MO, USA; 3Hamad Medical Corporation, Doha, Qatar Purpose: To describe a noninvasive instrument that estimates intraocular pressure during episodes of external globe compression and to demonstrate the accuracy and reliability of this device by comparing it to the intraocular pressures simultaneously and manometrically measured in cannulated eyes. Methods: A thin fluid-filled bladder was constructed from flexible and inelastic plastic sheeting and was connected to a pressure transducer with high pressure tubing. The output of the pressure transducer was sent to an amplifier and recorded. This device was validated by measuring induced pressure in the fluid-filled bladder while digital pressure was applied to one surface, and the other surface was placed directly against a human cadaver eye or in vivo pig eye. The human cadaver and in vivo pig eyes were each cannulated to provide a manometric intraocular pressure control. Results: The measurements obtained with the newly described device were within ~5% of simultaneously measured manometric intraocular pressures in both a human cadaver and in vivo pig eye model for a pressure range of ~15–100 mmHg. Conclusion: This novel noninvasive device is useful for estimating the intraocular pressure transients induced during any form of external globe compression; this is a clinical setting where no other devices can be used to estimate intraocular pressure. Keywords: glaucoma, intraocular pressure, tonometer, ocular compression

  10. Clinical Aspects of Combination of Ceramic and Acrylic Occlusal Surfaces

    Directory of Open Access Journals (Sweden)

    Z. Ozhohan

    2017-03-01

    Full Text Available The objective of the research was to develop and substantiate the methods of constructing the occlusal surfaces when manufacturing aesthetic fixed restorations through the combination of different materials. Materials and methods. The study included 65 patients with ceramic and acrylic occlusal surfaces of aesthetic fixed dental prostheses. Group I included 21 patients with a combination of ceramic and acrylic occlusal surfaces. Group II included 22 patients with a combination of ceramic occlusal surfaces. Group III included 22 patients with a combination of acrylic occlusal surfaces. The patients were observed 3, 6 and 12 months after prosthetic repair. Results. The greatest increase in the occlusal contact surface area of fixed restorations was observed in Group I, that is, when combining dental prostheses with ceramic and acrylic occlusal surfaces. Considering uneven abrasion of the occlusal surfaces, we do not recommend to combine different materials when veneering the occlusal surface of the antagonistic teeth. Conclusions. This study demonstrated the important role of the correct combination of materials when veneering the occlusal surfaces. Physical and chemical properties of materials, namely the abrasion resistance play a significant role in the long-term denture functioning. The smallest increase in the occlusal contact surface area was observed in Group II when combining ceramic occlusal surfaces. It was due to a good abrasion resistance of ceramics as compared to acrylic resin as well as the presence of the glazed layer which prevents the premature abrasion of the occlusal surfaces of the antagonistic teeth due to lower surface roughness. The combination of acrylic resin and ceramics when constructing the occlusal surfaces of fixed restorations in Group I demonstrated the highest rate of the increase in the occlusal contact surface area – 9.93%. It was due to a low hardness of acrylic resin and its high surface roughness. In

  11. Precision cosmology with weak gravitational lensing

    Science.gov (United States)

    Hearin, Andrew P.

    In recent years, cosmological science has developed a highly predictive model for the universe on large scales that is in quantitative agreement with a wide range of astronomical observations. While the number and diversity of successes of this model provide great confidence that our general picture of cosmology is correct, numerous puzzles remain. In this dissertation, I analyze the potential of planned and near future galaxy surveys to provide new understanding of several unanswered questions in cosmology, and address some of the leading challenges to this observational program. In particular, I study an emerging technique called cosmic shear, the weak gravitational lensing produced by large scale structure. I focus on developing strategies to optimally use the cosmic shear signal observed in galaxy imaging surveys to uncover the physics of dark energy and the early universe. In chapter 1 I give an overview of a few unsolved mysteries in cosmology and I motivate weak lensing as a cosmological probe. I discuss the use of weak lensing as a test of general relativity in chapter 2 and assess the threat to such tests presented by our uncertainty in the physics of galaxy formation. Interpreting the cosmic shear signal requires knowledge of the redshift distribution of the lensed galaxies. This redshift distribution will be significantly uncertain since it must be determined photometrically. In chapter 3 I investigate the influence of photometric redshift errors on our ability to constrain dark energy models with weak lensing. The ability to study dark energy with cosmic shear is also limited by the imprecision in our understanding of the physics of gravitational collapse. In chapter 4 I present the stringent calibration requirements on this source of uncertainty. I study the potential of weak lensing to resolve a debate over a long-standing anomaly in CMB measurements in chapter 5. Finally, in chapter 6 I summarize my findings and conclude with a brief discussion of my

  12. Posterior Segment Intraocular Foreign Body: Extraction Surgical Techniques, Timing, and Indications for Vitrectomy

    Directory of Open Access Journals (Sweden)

    Dante A. Guevara-Villarreal

    2016-01-01

    Full Text Available Ocular penetrating injury with Intraocular Foreign Body (IOFB is a common form of ocular injury. Several techniques to remove IOFB have been reported by different authors. The aim of this publication is to review different timing and surgical techniques related to the extraction of IOFB. Material and Methods. A PubMed search on “Extraction of Intraocular Foreign Body,” “Timing for Surgery Intraocular Foreign Body,” and “Surgical Technique Intraocular Foreign Body” was made. Results. Potential advantages of immediate and delayed IOFB removal have been reported with different results. Several techniques to remove IOFB have been reported by different authors with good results. Conclusion. The most important factor at the time to perform IOFB extraction is the experience of the surgeon.

  13. Bacillus cereus panophthalmitis associated with intraocular gas bubble.

    Science.gov (United States)

    al-Hemidan, A; Byrne-Rhodes, K A; Tabbara, K F

    1989-01-01

    It has become increasingly apparent that Bacillus cereus can cause a severe and devastating form of endophthalmitis following penetrating trauma by a metallic object. B. cereus is an uncommon aetiological agent in non-clostridial gas-forming infections. The patient studied in this single case report showed evidence of intraocular gas mimicking gas gangrene infection. The physiology of non-clostridial bacteria producing gas from anaerobic metabolic conditions is reviewed. Further intraocular and systemic complications which may be avoided by accurate and early diagnosis and the use of recommended treatment with antibiotics such as clindamycin. Images PMID:2493262

  14. Spectacle Independence after Cataract Extraction in Post-Radial Keratotomy Patients Using Hybrid Monovision with ReSTOR® Multifocal and TECNIS® Monofocal Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Isha Gupta

    2014-05-01

    Full Text Available Background: We report 2 patients who have undergone radial keratotomy (RK preceding ReSTOR® multifocal intraocular lens (IOL; Alcon, Fort Worth, Tex., USA implantation in their nondominant eyes and TECNIS® monofocal IOL (Abbott Medical Optics, Abbott Park, Ill., USA in their dominant eyes. Methods: Retrospective review of 2 patients who underwent hybrid monovision with ReSTOR® multifocal and TECHNIS® monofocal IOLs at the time of cataract surgery after a remote history of RK. Results: Implantation of the ReSTOR® multifocal and the TECHNIS® monofocal IOLs was successful, with no reported adverse events. The patients were able to achieve spectacle freedom. Conclusion: We report a novel technique for the management of post-RK patients to optimize their chances for spectacle independence.

  15. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    Directory of Open Access Journals (Sweden)

    Keslarek Amauri José

    2004-01-01

    Full Text Available Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM. Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+ have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.

  16. Planck 2015 results: XV. Gravitational lensing

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.

    2016-01-01

    We present the most significant measurement of the cosmic microwave background (CMB) lensing potential to date (at a level of 40σ), using temperature and polarization data from the Planck 2015 full-mission release. Using a polarization-only estimator, we detect lensing at a significance of 5σ. We...

  17. [Influence of different multifocal intraocular lens concepts on retinal stray light parameters].

    Science.gov (United States)

    Ehmer, A; Rabsilber, T M; Mannsfeld, A; Sanchez, M J; Holzer, M P; Auffarth, G U

    2011-10-01

    Multifocal intraocular lenses (MIOL) are known to induce various photic phenomena depending on the optical principle. The aim of this study was to investigate the correlation between stray light measurements performed with the C-Quant (Oculus, Germany) and the results of a subjective patient questionnaire. In this study three different MIOLs were compared: AMO ReZoom (refractive design, n=10), AMO ZM900 (diffractive design, n=10) and Oculentis Mplus (near segment design, n=10). Cataract and refractive patients were enrolled in the study. Functional results were evaluated at least 3 months postoperatively followed by stray light measurements and a subjective questionnaire. Surgery was performed for all patients without complications. The three groups were matched for age, IOL power and corrected distance visual acuity (CDVA). Significantly different stray light (median) values log(s) were found (Kruskal-Wallis test, p<0.05): 1.12 log (refractive), 1.13 log (segment) and 1.28 log (diffractive). The subjective questionnaire did not show differences in glare perception but refractive MIOL patients noticed more halos surrounding light sources than the diffractive and segment MIOL patients. Stray light and subjective photopic phenomena do not show any basic correlation. Measurements in patients with refractive MIOLs showed less stray light than near segment or diffractive MIOLs. However, refractive MIOLs induced more halos compared to the other groups analyzed.

  18. Bacterial adhesion to unworn and worn silicone hydrogel lenses.

    Science.gov (United States)

    Vijay, Ajay Kumar; Zhu, Hua; Ozkan, Jerome; Wu, Duojia; Masoudi, Simin; Bandara, Rani; Borazjani, Roya N; Willcox, Mark D P

    2012-08-01

    The objective of this study was to determine the bacterial adhesion to various silicone hydrogel lens materials and to determine whether lens wear modulated adhesion. Bacterial adhesion (total and viable cells) of Staphylococcus aureus (31, 38, and ATCC 6538) and Pseudomonas aeruginosa (6294, 6206, and GSU-3) to 10 commercially available different unworn and worn silicone hydrogel lenses was measured. Results of adhesion were correlated to polymer and surface properties of contact lenses. S. aureus adhesion to unworn lenses ranged from 2.8 × 10 to 4.4 × 10 colony forming units per lens. The highest adhesion was to lotrafilcon A lenses, and the lowest adhesion was to asmofilcon A lenses. P. aeruginosa adhesion to unworn lenses ranged from 8.9 × 10 to 3.2 × 10 colony forming units per lens. The highest adhesion was to comfilcon A lenses, and the lowest adhesion was to asmofilcon A and balafilcon A lenses. Lens wear altered bacterial adhesion, but the effect was specific to lens and strain type. Adhesion of bacteria, regardless of genera/species or lens wear, was generally correlated with the hydrophobicity of the lens; the less hydrophobic the lens surface, the greater the adhesion. P. aeruginosa adhered in higher numbers to lenses in comparison with S. aureus strains, regardless of the lens type or lens wear. The effect of lens wear was specific to strain and lens. Hydrophobicity of the silicone hydrogel lens surface influenced the adhesion of bacterial cells.

  19. Fimbrolide-coated antimicrobial lenses: their in vitro and in vivo effects.

    Science.gov (United States)

    Zhu, Hua; Kumar, Ajay; Ozkan, Jerome; Bandara, Rani; Ding, Aidong; Perera, Indrani; Steinberg, Peter; Kumar, Naresh; Lao, William; Griesser, Stefani S; Britcher, Leanne; Griesser, Hans J; Willcox, Mark D P

    2008-05-01

    To examine the ability of contact lenses coated with fimbrolides, inhibitors of bacterial quorum sensing, to prevent microbial adhesion and their safety during short-term clinical assessment. A fimbrolide was covalently attached to commercially available high Dk contact lenses. Subsequently Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, or Acanthamoeba sp. were added to the lenses and control uncoated contact lenses. Lenses plus microbes were incubated for 24 h, then washed thoroughly to remove non-adherent microbes. Lenses were macerated and resulting slurry plated onto agar plates. After appropriate incubation, the numbers of colony forming units of bacteria (or numbers of Acanthamoeba trophozoites measured using a hemocytometer) from fimbrolide-coated and uncoated lenses were examined. A Guinea Pig model of lens wear was used to assess the safety of lenses worn on a continuous basis for 1 month. In a separate study, 10 subjects wore fimbrolide-coated lenses for 24 h. The responses of the Guinea Pigs and human volunteers to the lenses were assessed by slit lamp examination. The fimbrolides-coated lenses reduced the adhesion of all bacterial strains tested, with reductions occurring of between 67 and 92%. For Acanthamoeba a reduction of 70% was seen. There were no significant differences in ocular responses to fimbrolide-coated lenses compared with controls in either the 1 month animal model or overnight human trial. Fimbrolide-coated lenses show promise as an antibacterial and anti-acanthamoebal coating on contact lenses and appear to be safe when worn on the eye in an animal model.

  20. Contact lenses fitting after intracorneal ring segments implantation in keratoconus

    Directory of Open Access Journals (Sweden)

    Luciane Bugmann Moreira

    2013-08-01

    Full Text Available PURPOSE: Evaluate contact lenses fitting after intracorneal ring implantation for keratoconus, its visual acuity and comfort. METHODS: Retrospective study of patients undergoing contact lenses fitting, after intracorneal ring for keratoconus. The criterion for contact lens fitting was unsatisfactory visual acuity with spectacle correction as referred by the patients. All patients were intolerants to contact lenses prior to intracorneal implantation. Visual acuity analysis was done by conversion of Snellen to logMAR scales. The comfort was evaluated according subjective questioning of good, medium or poor comfort. RESULTS: Nineteen patients were included in the study. Two patients (10.5% did not achieved good comfort with contact lenses and underwent penetrating keratoplasties. All the others 17 patients showed good or medium comfort. Four rigid gas-permeable contact lenses were fitted, one piggyback approach, 3 toric soft contact lenses, 2 soft lenses specially design for keratoconus and 7 disposable soft lenses. The average visual acuity improved from 0.77 ± 0.37 to 0.19 ± 0.13 logMAR units after contact lenses fitting. CONCLUSION: Contact lens fitting after intracorneal ring is possible, provides good comfort, improves visual acuity, and therefore, may postpone the need for penetrating keratoplasty.

  1. Influence of macular pigment optical density spatial distribution on intraocular scatter.

    Science.gov (United States)

    Putnam, Christopher M; Bland, Pauline J; Bassi, Carl J

    This study evaluated the summed measures of macular pigment optical density (MPOD) spatial distribution and their effects on intraocular scatter using a commercially available device (C-Quant, Oculus, USA). A customized heterochromatic flicker photometer (cHFP) device was used to measure MPOD spatial distribution across the central 16° using a 1° stimulus. MPOD was calculated as a discrete measure and summed measures across the central 1°, 3.3°, 10° and 16° diameters. Intraocular scatter was determined as a mean of 5 trials in which reliability and repeatability measures were met using the C-Quant. MPOD spatial distribution maps were constructed and the effects of both discrete and summed values on intraocular scatter were examined. Spatial mapping identified mean values for discrete MPOD [0.32 (s.d.=0.08)], MPOD summed across central 1° [0.37 (s.d.=0.11)], MPOD summed across central 3.3° [0.85 (s.d.=0.20)], MPOD summed across central 10° [1.60 (s.d.=0.35)] and MPOD summed across central 16° [1.78 (s.d.=0.39)]. Mean intraocular scatter was 0.83 (s.d.=0.16) log units. While there were consistent trends for an inverse relationship between MPOD and scatter, these relationships were not statistically significant. Correlations between the highest and lowest quartiles of MPOD within the central 1° were near significance. While there was an overall trend of decreased intraocular forward scatter with increased MPOD consistent with selective short wavelength visible light attenuation, neither discrete nor summed values of MPOD significantly influence intraocular scatter as measured by the C-Quant device. Published by Elsevier España, S.L.U.

  2. Relative radiosensitivity of rat lenses as a function of age

    International Nuclear Information System (INIS)

    Merriam, G.R. Jr.; Szechter, A.

    1975-01-01

    The effect of age on the development of radiation cataracts in rat lenses has been investigated using the Columbia--Sherman rat as an experiment model. A detailed pattern of age dependence was obtained at several different dose levels. In general at dose levels from 200 to 300 rads the lens changes occurred sooner and progressed faster in the adult lenses than in young lenses. In the dose range from 300 rads to 900 rads opacities developed sooner in the young lenses but progression was faster and severe opacities developed sooner in adult lenses. Above 900 rads opacities developed sooner and progressed faster in the young lenses. (U.S.)

  3. Astrophysical Applications of Gravitational Lensing

    Science.gov (United States)

    Mediavilla, Evencio; Muñoz, Jose A.; Garzón, Francisco; Mahoney, Terence J.

    2016-10-01

    Contributors; Participants; Preface; Acknowledgements; 1. Lensing basics Sherry H. Suyu; 2. Exoplanet microlensing Andrew Gould; 3. Case studies of microlensing Veronica Motta and Emilio Falco; 4. Microlensing of quasars and AGN Joachim Wambsganss; 5. DM in clusters and large-scale structure Peter Schneider; 6. The future of strong lensing Chris Fassnacht; 7. Methods for strong lens modelling Charles Keeton; 8. Tutorial on inverse ray shooting Jorge Jimenez-Vicente.

  4. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Directory of Open Access Journals (Sweden)

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  5. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Science.gov (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  6. Synthesis and characterization of copolymers 4,5-dihydroisoxazole and (-)-menthyl acrylates

    International Nuclear Information System (INIS)

    Passo, Joel A.; Merlo, Aloir A.; Eccher, Juliana; Bechtold, Ivan H.; Kelly, Stephen M.

    2012-01-01

    Five monomers 5-[4-(5-cyano-4,5-dihydroisoxazol-3-yl)phenoxy]undecyl acrylate (7a); n-alkyl 3-{4-[5-(acryloyloxyundecyl)oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylate (7b,c for n-butyl and n-hexyl, respectively); 3-{4-[5-(acryloyloxyundecyl) oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylic acid (7d) and (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl acrylate (9) and the corresponding copolymers 10a-d,11 and homopolymers 12 from 7a and 13 from 9 were designed and synthesized. Except for acrylate 9 which is derived from (-)-menthol, all of the monomers belong to the series containing the isoxazoline ring linked to the acrylate unit by a flexible spacer chain of eleven methylene units. They presented low glass temperature and despite birefringence behavior, these copolymers showed no mesomorphic properties. (author)

  7. Electron beam curable branched chain polyurethane acrylates for magnetic media coatings

    International Nuclear Information System (INIS)

    Ukachi, Takashi; Haga, Kei-ichi; Matsumura, Yoshio

    1989-01-01

    Electron beam curable binder resins have been studied to realize the high quality magnetic coatings. It was supposed that resins with a higher crosslink density could lead to magnetic coatings with higher abrasion resistance. Branched chain polyurethane acrylates show a higher degree of cure by irradiation with an electron beam in comparison with linear polyurethane acrylates. This paper describes the potential wear resistance between properties of magnetic coatings and the physical properties of the cured unpigmented branched chain polyurethane acrylates that were used as the binder resins. (author)

  8. Weak lensing in generalized gravity theories

    International Nuclear Information System (INIS)

    Acquaviva, Viviana; Baccigalupi, Carlo; Perrotta, Francesca

    2004-01-01

    We extend the theory of weak gravitational lensing to cosmologies with generalized gravity, described in the Lagrangian by a generic function depending on the Ricci scalar and a nonminimal coupled scalar field. We work out the generalized Poisson equations relating the dynamics of the fluctuating components to the two gauge-invariant scalar gravitational potentials, fixing the contributions from the modified background expansion and fluctuations. We show how the lensing equation gets modified by the cosmic expansion as well as by the presence of anisotropic stress, which is non-null at the linear level both in scalar-tensor gravity and in theories where the gravitational Lagrangian term features a nonminimal dependence on the Ricci scalar. Starting from the geodesic deviation, we derive the generalized expressions for the shear tensor and projected lensing potential, encoding the spacetime variation of the effective gravitational constant and isolating the contribution of the anisotropic stress, which introduces a correction due to the spatial correlation between the gravitational potentials. Finally, we work out the expressions of the lensing convergence power spectrum as well as the correlation between the lensing potential and the integrated Sachs-Wolfe effect affecting cosmic microwave background total intensity and polarization anisotropies. To illustrate phenomenologically the effects, we work out approximate expressions for the quantities above in extended quintessence scenarios where the scalar field coupled to gravity plays the role of the dark energy

  9. Effect of cholesterol deposition on bacterial adhesion to contact lenses.

    Science.gov (United States)

    Babaei Omali, Negar; Zhu, Hua; Zhao, Zhenjun; Ozkan, Jerome; Xu, Banglao; Borazjani, Roya; Willcox, Mark D P

    2011-08-01

    To examine the effect of cholesterol on the adhesion of bacteria to silicone hydrogel contact lenses. Contact lenses, collected from subjects wearing Acuvue Oasys or PureVision lenses, were extracted in chloroform:methanol (1:1, v/v) and amount of cholesterol was estimated by thin-layer chromatography. Unworn lenses were soaked in cholesterol, and the numbers of Pseudomonas aeruginosa strains or Staphylococcus aureus strains that adhered to the lenses were measured. Cholesterol was tested for effects on bacterial growth by incubating bacteria in medium containing cholesterol. From ex vivo PureVision lenses, 3.4 ± 0.3 μg/lens cholesterol was recovered, and from Acuvue Oasys lenses, 2.4 ± 0.2 to 1.0 ± 0.1 μg/lens cholesterol was extracted. Cholesterol did not alter the total or viable adhesion of any strain of P. aeruginosa or S. aureus (p > 0.05). However, worn PureVision lenses reduced the numbers of viable cells of P. aeruginosa (5.8 ± 0.4 log units) compared with unworn lenses (6.4 ± 0.2 log units, p = 0.001). Similarly, there were fewer numbers of S. aureus 031 adherent to worn PureVision (3.05 ± 0.8 log units) compared with unworn PureVision (4.6 ± 0.3 log units, p = 0.0001). Worn Acuvue Oasys lenses did not affect bacterial adhesion. Cholesterol showed no effect on the growth of any test strain. Although cholesterol has been shown to adsorb to contact lenses during wear, this lipid does not appear to modulate bacterial adhesion to a lens surface.

  10. The Initial Mass Function in the Nearest Strong Lenses from SNELLS: Assessing the Consistency of Lensing, Dynamical, and Spectroscopic Constraints

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Andrew B. [The Observatories of the Carnegie Institution for Science, Pasadena, CA (United States); Smith, Russell J. [Centre for Extragalactic Astronomy, University of Durham, South Road, Durham (United Kingdom); Conroy, Charlie [Department of Astronomy, Harvard University, Cambridge, MA (United States); Villaume, Alexa [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States); Van Dokkum, Pieter, E-mail: anewman@obs.carnegiescience.edu [Department of Astrophysical Sciences, Yale University, New Haven, CT (United States)

    2017-08-20

    We present new observations of the three nearest early-type galaxy (ETG) strong lenses discovered in the SINFONI Nearby Elliptical Lens Locator Survey (SNELLS). Based on their lensing masses, these ETGs were inferred to have a stellar initial mass function (IMF) consistent with that of the Milky Way, not the bottom-heavy IMF that has been reported as typical for high- σ ETGs based on lensing, dynamical, and stellar population synthesis techniques. We use these unique systems to test the consistency of IMF estimates derived from different methods. We first estimate the stellar M {sub *}/ L using lensing and stellar dynamics. We then fit high-quality optical spectra of the lenses using an updated version of the stellar population synthesis models developed by Conroy and van Dokkum. When examined individually, we find good agreement among these methods for one galaxy. The other two galaxies show 2–3 σ tension with lensing estimates, depending on the dark matter contribution, when considering IMFs that extend to 0.08 M {sub ⊙}. Allowing a variable low-mass cutoff or a nonparametric form of the IMF reduces the tension among the IMF estimates to <2 σ . There is moderate evidence for a reduced number of low-mass stars in the SNELLS spectra, but no such evidence in a composite spectrum of matched- σ ETGs drawn from the SDSS. Such variation in the form of the IMF at low stellar masses ( m ≲ 0.3 M {sub ⊙}), if present, could reconcile lensing/dynamical and spectroscopic IMF estimates for the SNELLS lenses and account for their lighter M {sub *}/ L relative to the mean matched- σ ETG. We provide the spectra used in this study to facilitate future comparisons.

  11. Electrochemical lysis at the stage of endoresection for large posterior intraocular tumors

    Directory of Open Access Journals (Sweden)

    Yu. A. Belyy

    2012-01-01

    Full Text Available Purpose: to design the new combined technique of endoresection with intraoperative intraocular electrochemical lysis at the tumor destruction stage for large posterior intraocular tumors.Methods: 3 patients (3 eyes with large choroidal melanomas t3N0M0 (tumor thickness — 8-10 mm, base diameter — 13-15 mm, juxtapapillary localization. Mean age was 55.4 years old. Endoresection with intraoperational intraocular electrochemical lysis of the tumor was performed. Electrochemical lysis was performed with use of the technical unit ECU 300 (Soering, Germany and the original method of combined intratumoral positioning of two platinum electrodes: anode and cathode.Results: the tumor was removal completely in all 3 cases. the anatomical retinal reattachment was reached in all patients. Sclera was safe in all 3 cases. Visual acuity was not changed (NLP. At the place of the removal tumor a surgical choroidal coloboma without pigmentation all over scleral bed and periphery was shown in all cases in distant postoperative period (from 1.5 to 3 years. No local recurrences or metastasis were revealed in all patients.Conclusion: Further investigations in clinical group are necessarily to determinate the real possibilities of the combined method and the indications for endoresection with intraoperative intraocular electrochemical lysis for large intraocular tumors. 

  12. Probing supervoids with weak lensing

    Science.gov (United States)

    Higuchi, Yuichi; Inoue, Kaiki Taro

    2018-05-01

    The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot, is one of such features. If a large underdense region (supervoid) resides towards the Cold Spot, we would be able to detect a systematic shape distortion in the images of background source galaxies via weak lensing effect. In order to estimate the detectability of such signals, we used the data of N-body simulations to simulate full-sky ray-tracing of source galaxies. We searched for a most prominent underdense region using the simulated convergence maps smoothed at a scale of 20° and obtained tangential shears around it. The lensing signal expected in a concordant Λ cold dark matter model can be detected at a signal-to-noise ratio S/N ˜ 3. If a supervoid with a radius of ˜200 h-1 Mpc and a density contrast δ0 ˜ -0.3 at the centre resides at a redshift z ˜ 0.2, on-going and near-future weak gravitational lensing surveys would detect a lensing signal with S/N ≳ 4 without resorting to stacking. From the tangential shear profile, we can obtain a constraint on the projected mass distribution of the supervoid.

  13. Lensing smoothing of BAO wiggles

    Energy Technology Data Exchange (ETDEWEB)

    Dio, Enea Di, E-mail: enea.didio@oats.inaf.it [INAF—Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34143 Trieste (Italy)

    2017-03-01

    We study non-perturbatively the effect of the deflection angle on the BAO wiggles of the matter power spectrum in real space. We show that from redshift z ∼2 this introduces a dispersion of roughly 1 Mpc at BAO scale, which corresponds approximately to a 1% effect. The lensing effect induced by the deflection angle, which is completely geometrical and survey independent, smears out the BAO wiggles. The effect on the power spectrum amplitude at BAO scale is about 0.1 % for z ∼2 and 0.2 % for z ∼4. We compare the smoothing effects induced by the lensing potential and non-linear structure formation, showing that the two effects become comparable at z ∼ 4, while the lensing effect dominates for sources at higher redshifts. We note that this effect is not accounted through BAO reconstruction techniques.

  14. Comparison of intraocular pressure measurement with Scheimpflug-based noncontact tonometer with and without hydrogel contact lenses.

    Science.gov (United States)

    Kumar, Mukesh; Shetty, Rohit; Jayadev, Chaitra; Dutta, Debarun; Nicolsan, Maneck D; Nagaraj, Sriharsha; Kumar, Rajesh S

    2015-04-01

    The objective was to determine the repeatability of intraocular pressure (IOP) measurements made through a soft contact lens (CL) using the Scheimpflug noncontact tonometry in healthy subjects. This prospective, randomized, single-center study included one eye of 88 subjects (40 male and 48 female). Only participants without glaucoma or any other ocular pathology were included in this study. Three consecutive IOP measurements by the Scheimpflug noncontact tonometry were performed with and without daily disposable hydrogel CLs (-0.50 DS) (Dailies-nelfilcon A, 69% water, 8.7 mm base curve, 14 mm diameter, center thickness 0.10 mm) by a single operator. To avoid any bias arising from diurnal variation, all measurements were made at a similar time of day (11 am ± 1 h). The repeatability of IOP measurements using the Scheimpflug noncontact tonometry with and without CLs was evaluated using Pearson's correlation analysis. Bland-Altman plotting was used to assess the limits of agreement between the measurements with and without CLs. The mean (± standard deviation) IOPs with and without CL were 13.80 ± 2.70 and 13.79 ± 2.54 mm of Hg respectively. The mean difference was 0.01 ± 0.16 (95% confidence interval, +1.97 to - 2.00) mm Hg. Statistical analysis via paired t-test showed no statistical difference between the two groups with (P = 0.15). A good correlation was found for IOP measurements with and without CL (r = 0.93, P < 0.001). Good test-retest reliability was found when IOP was measured with and without CL. There was no significant difference between IOP measured with and without CLs by Scheimpflug noncontact tonometry.

  15. Phacoemulsification and intraocular lens implantation in patients with oculocutaneous albinism.

    Science.gov (United States)

    Dávila, Pedro J; Ulloa-Padilla, Jan P; Izquierdo, Natalio J

    2017-01-01

    To evaluate the benefits of phacoemulsification and intraocular lens implantation in patients with oculocutaneous albinism (OCA). The charts of 195 patients with OCA who visited a local eye clinic were reviewed. All of these patients had genetic linkage analysis to establish OCA type. Frequencies and Paired t-test analysis were determined. Of the 195 patients, nine (4.6%) underwent clear cornea phacoemulsification with intraocular lens implantation. Seven of the nine patients with OCA had the Hermansky-Pudlak (HPS) type 1; two had OCA type 1. Pre-operative BCVA of all eyes ranged from 1.0 to 2.3 logMAR with a mean of 1.42 logMAR and a standard deviation of 0.41 logMAR. Post-operative BCVA of all eyes ranged from 1.0 to 1.30 logMAR with a mean of 1.04 logMAR and a standard deviation of 0.10 logMAR. BCVA improved after phacoemulsification surgery and intraocular lens implantation (p = 0.002). Pre-operative astigmatism of all eyes ranged from +0.50 to +5.75 with a mean of +2.25 and a standard deviation of +2.40. Post-operative astigmatism of all eyes ranged from +0.50 to +2.00 with a mean of +1.23 and a standard deviation of +0.42. Astigmatism improved after phacoemulsification surgery and intraocular lens implantation (p = 0.05). Nine patients with OCA who underwent phacoemulsification and intraocular lens implant experienced improved visual acuity and reduced astigmatism post-operatively. These results suggest cataract surgery may improve vision and refractive errors, and thus quality of life, in patients with albinism.

  16. Finding strong lenses in CFHTLS using convolutional neural networks

    Science.gov (United States)

    Jacobs, C.; Glazebrook, K.; Collett, T.; More, A.; McCarthy, C.

    2017-10-01

    We train and apply convolutional neural networks, a machine learning technique developed to learn from and classify image data, to Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) imaging for the identification of potential strong lensing systems. An ensemble of four convolutional neural networks was trained on images of simulated galaxy-galaxy lenses. The training sets consisted of a total of 62 406 simulated lenses and 64 673 non-lens negative examples generated with two different methodologies. An ensemble of trained networks was applied to all of the 171 deg2 of the CFHTLS wide field image data, identifying 18 861 candidates including 63 known and 139 other potential lens candidates. A second search of 1.4 million early-type galaxies selected from the survey catalogue as potential deflectors, identified 2465 candidates including 117 previously known lens candidates, 29 confirmed lenses/high-quality lens candidates, 266 novel probable or potential lenses and 2097 candidates we classify as false positives. For the catalogue-based search we estimate a completeness of 21-28 per cent with respect to detectable lenses and a purity of 15 per cent, with a false-positive rate of 1 in 671 images tested. We predict a human astronomer reviewing candidates produced by the system would identify 20 probable lenses and 100 possible lenses per hour in a sample selected by the robot. Convolutional neural networks are therefore a promising tool for use in the search for lenses in current and forthcoming surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope.

  17. Bubble-point measurement for the binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Baek, Seung-Hyun; Byun, Hun-Soo

    2016-01-01

    Highlights: • Phase behaviours for the (CO_2 + propargyl (meth)acrylate) systems by static method were measured. • (P, x) isotherms is obtained at pressures up to 19.14 MPa and at temperature of (313.2 to 393.2) K. • The (CO_2 + propargyl acrylate) and (CO_2 + propargyl methacrylate) systems exhibit type-I behaviour. - Abstract: Acrylate and methacrylate (acrylic acid type) are compounds with weak polarity which show a non-ideal behaviour. Phase behaviour of these systems play a significant role as organic solvents in industrial processes. High pressure phase behaviour data were reported for binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide. The bubble-point curves for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) mixtures were measured by static view cell apparatus at temperature range from 313.2 K to 393.2 K and at pressures below 19.14 MPa. The (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems exhibit type-I phase behaviour. The (carbon dioxide + (meth)acrylate) systems had continuous critical mixture curves with maximums in pressure located between the critical temperatures of carbon dioxide and propargyl acrylate or carbon dioxide and propargyl methacrylate. The solubility behaviour of propargyl (meth)acrylate in the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl acrylate) systems increases as the temperature increases at a fixed pressure. The experimental results for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems correlate with the Peng–Robinson equation of state using a van der Waals one-fluid mixing rule. The critical properties of propargyl acrylate and propargyl methacrylate were predicted with the Joback–Lyderson group contribution and Lee–Kesler method.

  18. Probabilistic Cosmological Mass Mapping from Weak Lensing Shear

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M. D.; Dawson, W. A. [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Ng, K. Y. [University of California, Davis, Davis, CA 95616 (United States); Marshall, P. J. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94035 (United States); Meyers, J. E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Bard, D. J., E-mail: schneider42@llnl.gov, E-mail: dstn@cmu.edu, E-mail: boutigny@in2p3.fr, E-mail: djbard@slac.stanford.edu, E-mail: jmeyers314@stanford.edu [National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720-8150 (United States)

    2017-04-10

    We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a spatial process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed cosmological lensing shear maps and a reconstruction of the mass distribution of the merging galaxy cluster Abell 781 using galaxy ellipticities measured with the Deep Lens Survey. Given interim posterior samples of lensing shear or convergence fields on the sky, we describe an algorithm to infer cosmological parameters via lens field marginalization. In the most general formulation of our algorithm we make no assumptions about weak shear or Gaussian-distributed shape noise or shears. Because we require solutions and matrix determinants of a linear system of dimension that scales with the number of galaxies, we expect our algorithm to require parallel high-performance computing resources for application to ongoing wide field lensing surveys.

  19. From Spheric to Aspheric Solid Polymer Lenses: A Review

    Directory of Open Access Journals (Sweden)

    Kuo-Yung Hung

    2011-01-01

    Full Text Available This paper presents a new approach in the use of MEMS technology to fabricate micro-optofluidic polymer solid lenses in order to achieve the desired profile, focal length, numerical aperture, and spot size. The resulting polymer solid lenses can be applied in optical data storage systems, imaging systems, and automated optical inspection systems. In order to meet the various needs of different applications, polymer solid lenses may have a spherical or aspherical shape. The method of fabricating polymer solid lenses is different from methods used to fabricate tunable lenses with variable focal length or needing an external control system to change the lens geometry. The current trend in polymer solid lenses is toward the fabrication of microlenses with a high numerical aperture, small clear aperture (<2 mm, and high transmittance. In this paper we focus on the use of thermal energy and electrostatic force in shaping the lens profile, including both spherical and aspherical lenses. In addition, the paper discusses how to fabricate a lens with a high numerical aperture of 0.6 using MEMS and also compares the optical characteristics of polymer lens materials, including SU-8, Norland Optical Adhesive (NOA, and cyclic olefin copolymer (COC. Finally, new concepts and applications related to micro-optofluidic lenses and polymer materials are also discussed.

  20. Microcyst response to high Dk/t silicone hydrogel contact lenses.

    Science.gov (United States)

    Keay, L; Sweeney, D F; Jalbert, I; Skotnitsky, C; Holden, B A

    2000-11-01

    To investigate the microcyst response to extended wear (EW) with high oxygen transmissible (Dk/t) silicone hydrogel lenses. Microcysts were monitored for 12 months in subjects wearing low Dk/t hydrogel lenses on a 6-night EW schedule or high Dk/t hydrogel lenses on a 30-night EW schedule. Subjects wearing low Dk/t lenses transferred to the high Dk/t EW lenses and schedule after 12 months and were monitored for a further 6 months. The mean number of microcysts did not deviate from baseline in the high Dk/t group. Microcysts in the low Dk/t group increased over 12 months, and more microcysts were observed in low Dk/t lens wearers compared with high Dk/t lens wearers after 3 months. Microcysts increased in 50% of subjects 1 week after transfer to high Dk/t lenses and returned to baseline levels seen with high Dk/t lens wear within 3 months. EW with high Dk/t silicone hydrogel lenses did not cause an increase in microcyst numbers. It is not necessary to discontinue lens wear with patients who transfer from low to high Dk/t lenses because the increase in microcysts is transitory. This result has implications for practitioners when fitting and assessing the success of high Dk/t hydrogel lenses.

  1. Three-dimensional quadrupole lenses made with permanent magnets

    International Nuclear Information System (INIS)

    Ivanov, A.S.

    1984-01-01

    The performance of accelerator systems with quadrupole magnets can be improved by using permanent magnets in quadrupole lenses. This requires better methods for treating the three-dimensional nature of the magnetic fields and the nonlinear characteristics of the magnets. A numerical method is described for simulating three-dimensional magnetic fields and used to analyze quadrupole lenses and doublets with permanent magnets. The results, which are confirmed experimentally, indicate that both the quadrupole magnetic gradient and the effective field length are changed in permanent-magnet quadrupole lenses when the pole lengths and the gap between the lenses are varied while the other characteristics of the magnets remain unchanged

  2. X-ray diffraction enhanced imaging study of intraocular tumors in human beings

    International Nuclear Information System (INIS)

    Tan Gao; Wang Huaqiao; Chen Yu; Yuan Qing; Li Gang; Zhu Peiping; Zhang Xiaodan; Zhong Xiufeng; Tang Jintian

    2010-01-01

    Diffraction enhanced imaging (DEI) with edge enhancement is suitable for the observation of weakly absorbing objects. The potential ability of the DEI was explored for displaying the microanatomy and pathology of human eyeball in this work. The images of surgical specimens from malignant intraocular tumor of hospitalized patients were taken using the hard X-rays from the topography station of Beamline 4W1A at Beijing Synchrotron Radiation Facility (BSRF). The obtained radiographic images were analyzed in correlation with those of pathology. The results show that the anatomic and pathologic details of intraocular tumors in human beings can be observed clearly by DEI for the first time, with good visualization of the microscopic details of eyeball ring such as sclera, choroid and other details of intraocular organelles. And the best resolution of DEI images reaches up to the magnitude of several tens of μm. The results suggest that it is capable of exhibiting clearly the details of intraocular tumor using DEI method. (authors)

  3. Quantum Spin Lenses in Atomic Arrays

    Directory of Open Access Journals (Sweden)

    A. W. Glaetzle

    2017-09-01

    Full Text Available We propose and discuss quantum spin lenses, where quantum states of delocalized spin excitations in an atomic medium are focused in space in a coherent quantum process down to (essentially single atoms. These can be employed to create controlled interactions in a quantum light-matter interface, where photonic qubits stored in an atomic ensemble are mapped to a quantum register represented by single atoms. We propose Hamiltonians for quantum spin lenses as inhomogeneous spin models on lattices, which can be realized with Rydberg atoms in 1D, 2D, and 3D, and with strings of trapped ions. We discuss both linear and nonlinear quantum spin lenses: in a nonlinear lens, repulsive spin-spin interactions lead to focusing dynamics conditional to the number of spin excitations. This allows the mapping of quantum superpositions of delocalized spin excitations to superpositions of spatial spin patterns, which can be addressed by light fields and manipulated. Finally, we propose multifocal quantum spin lenses as a way to generate and distribute entanglement between distant atoms in an atomic lattice array.

  4. A new design of a lead-acrylic shield for staff dose reduction in radial and femoral access coronary catheterization

    Energy Technology Data Exchange (ETDEWEB)

    Eder, H. [Deptartment of Radiation Protection (Germany); Seidenbusch, M.C.; Treitl, M. [Muenchen Univ. Clinical Center (Germany). Inst. for Clinical Radiology; Gilligan, P. [Mater Private Hospital, Dublin (Ireland). Medical Physics

    2015-10-15

    Today's standard radiation protection during coronary angiography and percutaneous coronary interventions is the combined use of lead acrylic shields and table-mounted lower body protection. Ambient dose measurements, however, have shown that these protection devices need improvement. Using an anthropomorphic physical phantom, various scenarios were investigated with respect to personnel exposure: (a) enlarging the shield (b) adding a flexible protective curtain to the bottom side of the shield, and (c) application of radioprotective patient drapes. For visualization of the dose reduction effect, Monte Carlo simulations were performed. The flexible curtain in contact with the patient's body reduces the ambient dose rate at the operator's position by up to (87.5 % ± 7.1) compared to the situation with the bare shield. The use of both the flexible curtain and the patient drape reduces the ambient dose rate by up to (90.8 % ± 7). Similar results were achieved for the assisting personnel when they were positioned next to the operator. In addition, the enlarged shield provides better protection of the head region of tall operators. Adding a flexible protective curtain to the bottom side of the shield can protect operators from high doses, especially for body parts which are not protected by lead aprons, e.g. head, and eye lenses. This may be important with respect to lower dose limits for eye lenses in future. The protective effect in real-life working conditions is still being evaluated in an ongoing clinical study.

  5. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    OpenAIRE

    Bojanić Vaso

    2010-01-01

    Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in c...

  6. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    International Nuclear Information System (INIS)

    Postolache, C.; Simion, Corina; Dragomir, A.; Ponta, C.; Chirvasoiu, G.; Postolache, Carmen

    1998-01-01

    The unfixed surface radioactive contamination for low energy β radionuclides ( 3 H and 14 C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm 3 . The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO 4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60 Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3 H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  7. [Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin].

    Science.gov (United States)

    Czerwińska, W; Kedzia, A; Kałowski, M

    1978-01-01

    The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective.

  8. [Changes in intraocular pressure depending on posture].

    Science.gov (United States)

    Barac, Ramona; Pop, Monica; Tătaru, C; Gheorghe, A; Bădescu, Silvia; Stanciu, Maria; Burcea, M

    2014-01-01

    Glaucoma is an important eye disease that, left untreated, causes irreversible blindness by affecting optic nerve threads. Decreasing intraocular pressure and maintaining it at a low level throughout the day is one of the objectives of antiglaucoma therapy. This is a prospective study conducted on a sample of 80 patients who presented at "Emergency Eye Hospital" Bucharest between 1st of December 2013 30th of July 2014. Patients were divided into two groups: 40 patients with glaucoma and 40 patients without glaucoma (control group). THE OBJECTIVE OF THE STUDY: To determine changes in intraocular pressure that may occur depending on body posture and the correlations between changes in intraocular pressure and glaucoma, obesity, hypertension. These IOP changes may be important in the progression of glaucoma regarding that one third of our time is spent on supine position during night. RESULTS AND CONCLUZIONS: IOP varies from sitting down to supine position. IOP increases in supine in most patients (with or without glaucoma) with an average of 1.25 mmHg. The increase among patients with glaucoma is higher (1.67 mmHg) compared to those without glaucoma (0.82 mmHg). In patients with hypertension and glaucoma, IOP increased with 2.62 mmHg. In patients with hypertension and obesity IOP increased with 2.5 mmHg.

  9. Near-infrared transillumination photography of intraocular tumours.

    Science.gov (United States)

    Krohn, Jørgen; Ulltang, Erlend; Kjersem, Bård

    2013-10-01

    To present a technique for near-infrared transillumination imaging of intraocular tumours based on the modifications of a conventional digital slit lamp camera system. The Haag-Streit Photo-Slit Lamp BX 900 (Haag-Streit AG) was used for transillumination photography by gently pressing the tip of the background illumination cable against the surface of the patient's eye. Thus the light from the flash unit was transmitted into the eye, leading to improved illumination and image resolution. The modification for near-infrared photography was done by replacing the original camera with a Canon EOS 30D (Canon Inc) converted by Advanced Camera Services Ltd. In this camera, the infrared blocking filter was exchanged for a 720 nm long-pass filter, so that the near-infrared part of the spectrum was recorded by the sensor. The technique was applied in eight patients: three with anterior choroidal melanoma, three with ciliary body melanoma and two with ocular pigment alterations. The good diagnostic quality of the photographs made it possible to evaluate the exact location and extent of the lesions in relation to pigmented intraocular landmarks such as the ora serrata and ciliary body. The photographic procedure did not lead to any complications. We recommend near-infrared transillumination photography as a supplementary diagnostic tool for the evaluation and documentation of anteriorly located intraocular tumours.

  10. Acrylic Triblock Copolymers Incorporating Isosorbide for Pressure Sensitive Adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, James J.; Hillmyer, Marc A.; Reineke, Theresa M. (UMM)

    2016-05-10

    A new monomer acetylated acrylic isosorbide (AAI) was prepared in two steps using common reagents without the need for column chromatography. Free radical polymerization of AAI afforded poly(acetylated acrylic isosorbide) (PAAI), which exhibited a glass transition temperature (Tg) = 95 °C and good thermal stability (Td, 5% weight loss; N2 = 331 °C, air = 291 °C). A series of ABA triblock copolymers with either poly(n-butyl acrylate) (PnBA) or poly(2-ethylhexyl acrylate) (PEHA) as the low Tg midblocks and PAAI as the high Tg end blocks were prepared using Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization. The triblock copolymers ranging from 8–24 wt % PAAI were evaluated as pressure sensitive adhesives by 180° peel, loop tack, and static shear testing. While the PAAI-PEHA-PAAI series exhibited poor adhesive qualities, the PAAI-PnBA-PAAI series of triblock copolymers demonstrated peel forces up to 2.9 N cm–1, tack forces up to 3.2 N cm–1, and no shear failure up to 10000 min. Dynamic mechanical analysis indicated that PAAI-PEHA-PAAI lacked the dissipative qualities needed to form an adhesive bond with the substrate, while the PAAI-PnBA-PAAI series exhibited a dynamic mechanical response consistent with related high performing PSAs.

  11. Small-Gauge Pars Plana Vitrectomy for the Management of Symptomatic Posterior Vitreous Detachment after Phacoemulsification and Multifocal Intraocular Lens Implantation: A Pilot Study from the Pan-American Collaborative Retina Study Group

    Science.gov (United States)

    Navarro, Rodrigo M.; Machado, Leonardo M.; Maia, Ossires; Wu, Lihteh; Farah, Michel E.; Magalhaes, Octaviano; Arevalo, J. Fernando; Maia, Mauricio

    2015-01-01

    Purpose. To determine the efficacy of 23-gauge pars plana vitrectomy (PPV) for symptomatic posterior vitreous detachment (PVD) on visual acuity (VA) and quality after multifocal intraocular lenses (IOLs). Methods. In this prospective case series, patients who developed symptomatic PVD and were not satisfied with visual quality due to floaters and halos after multifocal IOL implantation underwent PPV. Examinations included LogMAR uncorrected visual acuity (UCVA), intraocular pressure, biomicroscopy, and indirect ophthalmoscopy at baseline and 1, 7, 30, and 180 days postoperatively. Ultrasonography and aberrometry were performed. The Visual Functioning Questionnaire 25 (VFQ-25) was administered preoperatively and at 30 days postoperatively. Both the postoperative UCVA and questionnaire results were compared to preoperative findings using the Wilcoxon test. Results. Sixteen eyes of 8 patients were included. VA significantly improved from 0.17 to 0.09 postoperatively (P = 0.017). All patients reported improvement of halos, glare, and floaters. VFQ-25 scores significantly improved in general vision (P = 0.023), near activities (P = 0.043), distance activities (P = 0.041), mental health (P = 0.011), role difficulties (P = 0.042), and driving (P = 0.016). Conclusion. PPV may increase UCVA and quality of vision in patients with bilateral multifocal IOLs and symptomatic PVD. Larger studies are advised. PMID:26504590

  12. Homogeneous synthesis of cellulose acrylate-g-poly (n-alkyl acrylate) solid-solid phase change materials via free radical polymerization.

    Science.gov (United States)

    Qian, Yong-Qiang; Han, Na; Bo, Yi-Wen; Tan, Lin-Li; Zhang, Long-Fei; Zhang, Xing-Xiang

    2018-08-01

    A novel solid-solid phase change materials, namely, cellulose acrylate-g-poly (n-alkyl acrylate) (CA-g-PAn) (n = 14, 16 and 18) were successfully synthesized by free radical polymerization in N, N-dimethylacetamide (DMAc). The successful grafting was confirmed by fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (NMR). The properties of the CA-g-PAn copolymers were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The phase change temperatures and the melting enthalpies of CA-g-PAn copolymers are in the range of 10.1-53.2 °C and 15-95 J/g, respectively. It can be adjusted by the contents of poly (n-alkyl acrylate) and the length of alkyl side-chain. The thermal resistant temperatures of CA-g-PA14, 16 and 18 copolymers are 308 °C, 292 °C and 273 °C, respectively. It show that all of grafting materials exhibit good thermal stability and shape stability. Therefore, it is expected to be applied in the cellulose-based thermos-regulating field. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Intraocular pressure measurement: Goldmann Applanation Tonometer vs non contact airpuff tonometer.

    Science.gov (United States)

    Shah, Masood Alam; Bin Saleem, Khalid; Mehmood, Talat

    2012-01-01

    An accurate assessment of Intraocular pressure (IOP) is vital in establishing diagnosis of Glaucoma and decision making regarding various treatment modalities available. The purpose of this study is to compare Goldmann Applanation Tonometer (GAT) with Air puff tonometer. Cross-sectional comparative study conducted. 73 eyes from 73 patients were included in this study and intraocular pressure (IOP) was measured by GAT and PT100 at Sheikh Khalifa Bin Zayed Hospital, Muzaffarabad, Benazir Shaheed Teaching Hospital, Abbottabad. Mean age of the patients was 53.17 +/- 13.80 years. Mean IOP measurements showed significant differences in measurements performed by the two tonometers (p contact air-puff tonometer, the Goldmann applanation tonometer is a reliable and consistent technique for measurement of intraocular pressure.

  14. Allergic contact dermatitis from sculptured acrylic nails: special presentation with an airborne pattern

    Science.gov (United States)

    Maio, Paula; Carvalho, Rodrigo; Amaro, Cristina; Santos, Raquel; Cardoso, Jorge

    2012-01-01

    Methylmethacrylate was first reported in 1941 as a cause of contact dermatitis. Since then, occupational contact allergies to acrylates in dentistry, orthopedic surgery, printing industry and industry have been reported, but few reports are found in the literature as a consequence of the contact with sculptured artificial acrylic nails which are increasingly popular. We describe here 3 patients with contact allergy to acrylates in artificial sculptured nails. Patch tests were performed with the Portuguese baseline series of contact allergens and an extended series of acrylates were applied. In particular, we tested three female patients with allergic contact dermatitis from sculptured acrylic nails. Two of these patients were both customers and also technical nail beauticians. Two patients developed periungual eczema; one presented only with face and eyelid dermatitis had no other lesions. The tests showed positive reaction to 2-hydroxyethylmethacrylate (2-HEMA) and 2-hydroxypropylmethacrylate (2-HPMA) in all the three patients. Our cases demonstrate the variety of clinical presentations of allergic contact dermatitis from acrylic sculptured nails. They show the need to warn patients of persistent and sometimes permanent side effects of these products. They also emphasize the importance of cosmetic ingredient labeling. PMID:25386316

  15. Lenses and Perception: Investigations with Light

    Science.gov (United States)

    Akcay, Hakan

    2005-01-01

    The main goals of these activities are to help students learn how a convex lens can serve as a magnifying lens and how light travels and creates images. These explorations will introduce middle school students to different types of lenses and how they work. Students will observe and describe how lenses bend light that passes through them and how…

  16. X-ray lenses with large aperture

    International Nuclear Information System (INIS)

    Simon, Markus

    2010-01-01

    Up to now, most X-ray imaging setups are based on absorption contrast imaging. There is a demand for focused X-rays in many X-ray analysis applications, either to increase the resolution of an imaging system, or, to reduce the time effort of an experiment through higher photon flux. For photon energies higher than 15 keV refractive X-ray optics are more efficient in comparison to non-refractive X-ray optics. The aim of this work was to develop X-ray lenses with large apertures and high transparency. By increasing the number of refracting surfaces while removing unnecessary lens material such lenses have been developed. Utilizing this approach the overall beam deflection angle is large with respect to the lens material it propagates through and so the transparency of the lens is increased. Within this work, X-ray lenses consisting of several thousands of prisms with an edge length in the range of micrometers have been developed and fabricated by deep X-ray lithography. Deep X-ray lithography enables high precision microstrucures with smooth sidewalls and large aspect ratios. The aperture of high-transparency X-ray lenses made this way is greater than 1 mm. They are suitable for photon energies in the range of 8 keV to 24 keV and offer a focal width of smaller than 10 μm at a transparency of around 40%. Furthermore, rolled X-ray lenses have been developed, that are made out of a microstructured polyimide film, which is cut according to the requirements regarding focal length and photon energy. The microstructured film is fabricated by molding, using an anisotropically etched silicon wafer as molding tool. Its mean roughness is in the range of nanometers. The film features prismatic structures, its surface topology is similar to an asparagus field. The measured diameter of the point focus was 18 μm to 31 μm, the calculated opticla efficiency was 37%. Future work will concentrate on increasing the aspect ratio of Prism Lenses and on increasing the rolling accuracy

  17. Comparative evaluation of rotational stability and visual outcome of toric intraocular lenses with and without a capsular tension ring.

    Science.gov (United States)

    Rastogi, Anju; Khanam, Samreen; Goel, Yashpal; Thacker, Prolima; Kumar, Prateek

    2018-03-01

    To evaluate the rotational stability of toric intraocular lens (IOL) when co-implanted with a capsular tension ring (CTR) as compared to that of a toric IOL without a CTR. This was a prospective randomized clinical trial performed in a tertiary care centre in India. Fifty adult human eyes with visually significant cataract and regular corneal astigmatism ≥1.5D divided into two groups of 25 eyes each, A and B by simple randomization. Eyes with corneal pathology, lens subluxation, and a specular endothelial cell count IOL. In Group A, a CTR was put in the bag before IOL implantation. The groups were called for follow-up on day 1, 1 week, 1 month, and 3 months, postoperatively. The axis of the toric IOL on each visit was measured by slit lamp imaging in retroillumination and analyzed digitally. Mean rotation of toric IOL at 3 months postoperatively was 1.85 ± 1.72° in Group A and 4.02 ± 2.04° in Group B. The difference was statistically significant (P = 0.003). Coimplantation of a CTR is a safe and effective technique for ensuring better rotational stability of toric IOLs.

  18. Comparison between liquid and solid tunable focus lenses

    International Nuclear Information System (INIS)

    Santiago-Alvarado, A; Cruz-Martinez, V M; Vazquez-Montiel, S; Munoz-Lopez, J; Diaz-Gonzalez, G; Campos-Garcia, M

    2011-01-01

    Nowadays more reports in the use of tunable lenses are reported, it is due to the benefits they offer in optical systems design. A tunable lens is an optical system that can focus on a range of positions by changing dynamically one of its geometric parameters. There are several types of tunable lenses, the most known types are the liquid, the solid elastic, with variable refractive index, and lenses that use a dielectric medium. This paper presents the analysis and opto-mechanical design of two tunable lenses, a liquid lens and another Solid Elastic Lens (SEL). Both lenses are made in mounting aluminium and polydimethylsiloxane (PDMS) as refractor medium, the liquid lens use two elastic membranes containing a liquid medium between them while the SEL only use PDMS material as body of the lens (medium refractor). We describe the opto-mechanical performance of both types of lens highlighting the main features of each. Finally, results of a opto-functional comparison between these prototypes are showed.

  19. Planck 2013 results. XVII. Gravitational lensing by large-scale structure

    CERN Document Server

    Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Basak, S.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Dechelette, T.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Ho, S.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lavabre, A.; Lawrence, C.R.; Leahy, J.P.; Leonardi, R.; Leon-Tavares, J.; Lesgourgues, J.; Lewis, A.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Pullen, A.R.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; White, M.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    On the arcminute angular scales probed by Planck, the CMB anisotropies are gently perturbed by gravitational lensing. Here we present a detailed study of this effect, detecting lensing independently in the 100, 143, and 217GHz frequency bands with an overall significance of greater than 25sigma. We use the temperature-gradient correlations induced by lensing to reconstruct a (noisy) map of the CMB lensing potential, which provides an integrated measure of the mass distribution back to the CMB last-scattering surface. Our lensing potential map is significantly correlated with other tracers of mass, a fact which we demonstrate using several representative tracers of large-scale structure. We estimate the power spectrum of the lensing potential, finding generally good agreement with expectations from the best-fitting LCDM model for the Planck temperature power spectrum, showing that this measurement at z=1100 correctly predicts the properties of the lower-redshift, later-time structures which source the lensing ...

  20. Gravitational lensing by spinning and radially moving lenses

    International Nuclear Information System (INIS)

    Sereno, M.

    2002-01-01

    The effect of currents of mass on bending of light rays is considered in the weak field regime. Following Fermat's principle and the standard theory of gravitational lensing, we derive the gravito-magnetic correction to time delay function and deflection angle caused by a geometrically-thin lens. The cases of both rotating and shifting deflectors are discussed

  1. [Lens exchange for subluxation of posterior chamber lenses implanted in the capsular bag or in the ciliary sulcus].

    Science.gov (United States)

    Stürmer, J

    2013-04-01

    There are an increasing number of patients with decreased vision due to dislocated posterior chamber lenses, with pseudoexfoliation being the main risk factor. Various techniques for refixation of the subluxated posterior chamber IOL have been described. Experience with our technique of IOL-explantation, anterior vitrectomy and implantation of an Artisan anterior chamber lens are presented. In a retrospective study design all lens exchanges with implantation of an Artisan anterior chamber lens performed between 2003 and 2012 are analyzed. The study included 65 eyes of 61 patients (age 79.6 ± 9.2 years: 43-98). The majority of eyes (46/65; 70.8%) had Sundown Syndrome (late in-the-bag intraocular lens dislocation), in 19 eyes the posterior chamber lens was implanted primary or secondary into the ciliary sulcus. In the 46 eyes with Sundown Syndrome cataract surgery with implantation of a posterior chamber lens in the capsular bag was performed 7.4 ± 3.7 (1-22) years before subluxation within the bag. Pseudoexfoliation was the main risk factor in 42/46 (91.2%) of these eyes. A capsular tension ring (CTR) was implanted during cataract surgery in 34/46 (73.9%) eyes. The 34 IOLs with a CTR luxated significantly earlier (p IOLs without a CTR (6.6 ± 3.6 years; median 5.8 vs. 9.4 ± 3.1 years; median 9.2). The average visual gain was 0.2 logMAR in the group of luxated capsular bag lenses and 0.12 logMAR in the group of luxated sulcus lenses. Postoperative IOP decompensation was seen in 17/65 (26.2%) eyes (requiring IOP-lowering surgery in 8 eyes), 7 eyes developed corneal decompensation, 5 eyes had central retinal vein occlusion and one eye developed postoperative endophthalmitis. Lens exchange with implantation of an Artisan anterior chamber lens has become a routine procedure to improve vision in patients with subluxated IOLs. Postoperative IOP decompensation and vascular problems are the major complications. Georg Thieme Verlag KG Stuttgart · New York.

  2. Constraints on cosmological models from strong gravitational lensing systems

    International Nuclear Information System (INIS)

    Cao, Shuo; Pan, Yu; Zhu, Zong-Hong; Biesiada, Marek; Godlowski, Wlodzimierz

    2012-01-01

    Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning the Hubble constant independent ratio between two angular diameter distances D ds /D s from various large systematic gravitational lens surveys and lensing by galaxy clusters combined with X-ray observations, and check the possibility to use it in the future as complementary to other cosmological probes. On one hand, strongly gravitationally lensed quasar-galaxy systems create such a new opportunity by combining stellar kinematics (central velocity dispersion measurements) with lensing geometry (Einstein radius determination from position of images). We apply such a method to a combined gravitational lens data set including 70 data points from Sloan Lens ACS (SLACS) and Lens Structure and Dynamics survey (LSD). On the other hand, a new sample of 10 lensing galaxy clusters with redshifts ranging from 0.1 to 0.6 carefully selected from strong gravitational lensing systems with both X-ray satellite observations and optical giant luminous arcs, is also used to constrain three dark energy models (ΛCDM, constant w and CPL) under a flat universe assumption. For the full sample (n = 80) and the restricted sample (n = 46) including 36 two-image lenses and 10 strong lensing arcs, we obtain relatively good fitting values of basic cosmological parameters, which generally agree with the results already known in the literature. This results encourages further development of this method and its use on larger samples obtained in the future

  3. Constraints on cosmological models from strong gravitational lensing systems

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Shuo; Pan, Yu; Zhu, Zong-Hong [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Biesiada, Marek [Department of Astrophysics and Cosmology, Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Godlowski, Wlodzimierz, E-mail: baodingcaoshuo@163.com, E-mail: panyu@cqupt.edu.cn, E-mail: biesiada@us.edu.pl, E-mail: godlowski@uni.opole.pl, E-mail: zhuzh@bnu.edu.cn [Institute of Physics, Opole University, Oleska 48, 45-052 Opole (Poland)

    2012-03-01

    Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning the Hubble constant independent ratio between two angular diameter distances D{sub ds}/D{sub s} from various large systematic gravitational lens surveys and lensing by galaxy clusters combined with X-ray observations, and check the possibility to use it in the future as complementary to other cosmological probes. On one hand, strongly gravitationally lensed quasar-galaxy systems create such a new opportunity by combining stellar kinematics (central velocity dispersion measurements) with lensing geometry (Einstein radius determination from position of images). We apply such a method to a combined gravitational lens data set including 70 data points from Sloan Lens ACS (SLACS) and Lens Structure and Dynamics survey (LSD). On the other hand, a new sample of 10 lensing galaxy clusters with redshifts ranging from 0.1 to 0.6 carefully selected from strong gravitational lensing systems with both X-ray satellite observations and optical giant luminous arcs, is also used to constrain three dark energy models (ΛCDM, constant w and CPL) under a flat universe assumption. For the full sample (n = 80) and the restricted sample (n = 46) including 36 two-image lenses and 10 strong lensing arcs, we obtain relatively good fitting values of basic cosmological parameters, which generally agree with the results already known in the literature. This results encourages further development of this method and its use on larger samples obtained in the future.

  4. Plasma lenses for SLAC Final Focus Test facility

    International Nuclear Information System (INIS)

    Betz, D.; Cline, D.; Joshi, C.; Rajagopalan, S.; Rosenzweig, J.; Su, J.J.; Williams, R.; Chen, P.; Gundersen, M.; Katsouleas, T.; Norem, J.

    1991-01-01

    A collaborative group of accelerator and plasma physicists and engineers has formed with an interest in exploring the use of plasma lenses to meet the needs of future colliders. Analytic and computational models of plasma lenses are briefly reviewed and several design examples for the SLAC Final Focus Test Beam are presented. The examples include discrete, thick, and adiabatic lenses. A potential plasma source with desirable lens characteristics is presented

  5. Acrylic composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Meda, Yutaka.

    1969-01-01

    An acrylic composition and a process for the production of an easily hardenable coating material by irradiating with active energy, particularly electron beams and ultraviolet light, are provided using a mixture of 10%-100% by weight of an unsaturated compound and 90%-0% of a vinyl monomer. The composition has a high degree of polymerization, low volatility, low viscosity and other properties similar to thermosetting acrylic or amino alkyd resins. The aforesaid unsaturated compound is produced by primarily reacting saturated cyclocarboxylic anhydride and/or alpha-, beta-ethylene unsaturated carboxylic anhydride and by secondarily reacting an epoxy radical-containing vinyl monomer by addition reaction with polyhydric alcohols. Each reaction is conducted in the presence of a tertiary amino radical-containing vinyl monomer as a catalyst. The cross-linking is effected generally with an electron beam accelerator of 0.1-2.0 MeV or with a light beam in the 2,000-8,000A range in the presence of a photosensitive agent. In one example, 62 parts of ethylene glycol and 196 parts of maleic anhydride were dissolved in a mixture consisting of 100 parts of n-butyl methacrylate and 30 parts of styrene. To the mixture were added 5 parts of 2-methyl 5 vinyl piridine and 0.005 part of hydroquinone monomethyl ether. After the reaction at 90 0 C for 3 hours, a compound HOC:O-CH=CHC:OCH 2 CH 2 C:OOH was produced. To this solution were added 285 parts of glycidyl methacrylate. After the reaction at 90 0 C for 6 hours, 95% of the carboxylic acids reacted with epoxy radicals. Fourteen examples are given. (Iwakiri, K.)

  6. Surface morphology changes of acrylic resins during finishing and polishing phases

    Directory of Open Access Journals (Sweden)

    Glaucio Serra

    2013-12-01

    Full Text Available INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.

  7. Influence of protein deposition on bacterial adhesion to contact lenses.

    Science.gov (United States)

    Subbaraman, Lakshman N; Borazjani, Roya; Zhu, Hua; Zhao, Zhenjun; Jones, Lyndon; Willcox, Mark D P

    2011-08-01

    The aim of the study is to determine the adhesion of Gram positive and Gram negative bacteria onto conventional hydrogel (CH) and silicone hydrogel (SH) contact lens materials with and without lysozyme, lactoferrin, and albumin coating. Four lens types (three SH-balafilcon A, lotrafilcon B, and senofilcon A; one CH-etafilcon A) were coated with lysozyme, lactoferrin, or albumin (uncoated lenses acted as controls) and then incubated in Staphylococcus aureus (Saur 31) or either of two strains of Pseudomonas aeruginosa (Paer 6294 and 6206) for 24 h at 37 °C. The total counts of the adhered bacteria were determined using the H-thymidine method and viable counts by counting the number of colony-forming units on agar media. All three strains adhered significantly lower to uncoated etafilcon A lenses compared with uncoated SH lenses (p 0.05). Lactoferrin coating on lenses increased binding (total and viable counts) of Saur 31 (p lenses showed significantly higher total counts (p lenses. Albumin coating of lenses increased binding (total and viable counts) of all three strains (p lenses does not possess antibacterial activity against certain bacterial strains, whereas lactoferrin possess an antibacterial effect against strains of P. aeruginosa.

  8. Ocular onchocerciasis in the Yanomami communities from Brazilian Amazon: effects on intraocular pressure.

    Science.gov (United States)

    Herzog-Neto, Guilherme; Jaegger, Karen; Nascimento, Erika S do; Marchon-Silva, Verônica; Banic, Dalma M; Maia-Herzog, Marilza

    2014-01-01

    To determine the influence of onchocercal eye disease on the intraocular pressure of the Yanomami Tribe Aratha-ú of Roraima State, Brazil, considered endemic for onchocerciasis, a total of 86 patients were submitted to an ophthalmologic exam that included external examination, slit lamp examination, intraocular pressure measurement, and a fundus ophthalmoscope examination. A high prevalence of onchocerciasis-related eye lesions was encountered in 68.6% of the patients. Punctate keratitis and microfilariae in the anterior chamber were found in ∼28%. The mean of intraocular eye pressure found was 10.47 mm of Hg.

  9. Visual performance with sport-tinted contact lenses in natural sunlight.

    Science.gov (United States)

    Erickson, Graham B; Horn, Fraser C; Barney, Tyler; Pexton, Brett; Baird, Richard Y

    2009-05-01

    The use of tinted and clear contact lenses (CLs) in all aspects of life is becoming a more popular occurrence, particularly in athletic activities. This study broadens previous research regarding performance-tinted CLs and their effects on measures of visual performance. Thirty-three subjects (14 male, 19 female) were fitted with clear B&L Optima 38, 50% visible light transmission Amber and 36% visible light transmission Gray-Green Nike Maxsight CLs in an individualized randomized sequence. Subjects were dark-adapted with welding goggles before testing and in between subtests involving a Bailey-Lovie chart and the Haynes Distance Rock test. The sequence of testing was repeated for each lens modality. The Amber and Gray-Green lenses enabled subjects to recover vision faster in bright sunlight compared with clear lenses. Also, subjects were able to achieve better visual recognition in bright sunlight when compared with clear lenses. Additionally, the lenses allowed the subjects to alternate fixation between a bright and shaded target at a more rapid rate in bright sunlight as compared with clear lenses. Subjects preferred both the Amber and Gray-Green lenses over clear lenses in the bright and shadowed target conditions. The results of the current study show that Maxsight Amber and Gray-Green lenses provide better contrast discrimination in bright sunlight, better contrast discrimination when alternating between bright and shaded target conditions, better speed of visual recovery in bright sunlight, and better overall visual performance in bright and shaded target conditions compared with clear lenses.

  10. Sensitivity of the corneal-plane refractive compensation to change in power and axial position of an intraocular lens

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2009-12-01

    Full Text Available If an intraocular lens is displaced or if its power is changed what are the consequences for the refractive compensation of the eye?  Gaussian optics is used to obtain explicit formulae for the sensitivityof the corneal-plane refractive compensation (also called the refraction, refractive state, etc to change in power and axial displacement of a thin intraocular lens implanted in a simple eye.  In particular, for a pseudophakic Gullstrand simplified eye with intraocular lens placed 5 mm behind the cornea the sensitivity to errors in the power of the intraocular lens is about  71 . 0 − 71 for an intraocular lens of power   for an intraocular lens of power 20 D, that is, the refractive compensation decreases by about 0.71 dioptres per dioptre increase in the power of the intraocular lens.  More generally the sensitivity is approximately  ( m   0037 . 0 63 . 0 F − − 0.63 ( 003 . 0 63 . 0 − − (0.0037mF where FI is the power of the intraocular lens.  Also for Gullstrand’s simplified eye the sensitivity of refractive compensation to axial displacement of the intraocular lens is approximately linear in FI about  (64D FI, in fact.  That is, for each dioptre of the power of the intraocular lens the refractive compensation increases by about 0.064 dioptres per millimetre of axial displacement towards the retina. 

  11. Intraocular Pressure Increases After Intraarticular Knee Injection With Triamcinolone but Not Hyaluronic Acid.

    Science.gov (United States)

    Taliaferro, Kevin; Crawford, Alexander; Jabara, Justin; Lynch, Jonathan; Jung, Edward; Zvirbulis, Raimonds; Banka, Trevor

    2018-03-09

    Intraarticular steroid injections are a common first-line therapy for severe osteoarthritis, which affects an estimated 27 million people in the United States. Although topical, oral, intranasal, and inhalational steroids are known to increase intraocular pressure in some patients, the effect of intraarticular steroid injections on intraocular pressure has not been investigated, to the best of our knowledge. If elevated intraocular pressure is sustained for long periods of time or is of sufficient magnitude acutely, permanent loss of the visual field can occur. How does intraocular pressure change 1 week after an intraarticular knee injection either with triamcinolone acetonide or hyaluronic acid? A nonrandomized, nonblinded prospective cohort study was conducted at an outpatient, ambulatory orthopaedic clinic. This study compared intraocular pressure elevation before and 1 week after intraarticular knee injection of triamcinolone acetonide versus hyaluronic acid for management of primary osteoarthritis of the knee. Patients self-selected to be injected in their knee with either triamcinolone acetonide or hyaluronic acid before being informed of the study. The primary endpoint was intraocular pressure elevation of ≥ 7 mm Hg 1 week after injection. This cutoff is determined as the minimum significant pressure change in the ophthalmology literature recognized as an intermediate responder to steroids. Intraocular pressure was measured using a handheld Tono-Pen® applanation device. This device is frequently used in intraocular pressure measurement in clinical and research settings; 10 sequential measurements are obtained and averaged with a confidence interval. Only measurements with a 95% confidence interval were used. Over a 6-month period, a total of 96 patients were approached to enroll in the study. Sixty-two patients out of 96 approached (65%) agreed. Thirty-one (50%) were injected with triamcinolone and 31 (50%) were injected with hyaluronic acid. Patients

  12. Polyurethane acrylate networks including cellulose nanocrystals: a comparison between UV and EB- curing

    Science.gov (United States)

    Furtak-Wrona, K.; Kozik-Ostrówka, P.; Jadwiszczak, K.; Maigret, J. E.; Aguié-Béghin, V.; Coqueret, X.

    2018-01-01

    A water-based polyurethane (PUR) acrylate water emulsion was selected as a radiation curable matrix for preparing nanocomposites including cellulose nanocrystals (CNC) prepared by controlled hydrolysis of Ramie fibers. Cross-linking polymerization of samples prepared in the form of films or of 1 mm-thick bars was either initiated by exposure to the 395 nm light of a high intensity LED lamp or by treatment with low energy electron beam (EB). The conversion level of acrylate functions in samples submitted to increasing radiation doses was monitored by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to characterize changes in the glass transition temperature of the PUR-CNC nanocomposites as a function of acrylate conversion and of CNC content. Micromechanical testing indicates the positive effect of 1 wt% CNC on Young's modulus and on the tensile strength at break (σ) of cured nanocomposites. The presence of CNC in the PUR acrylate matrix was shown to double the σ value of the nanocomposite cured to an acrylate conversion level of 85% by treatment with a 25 kGy dose under EB, whereas no increase of σ was observed in UV-cured samples exhibiting the same acrylate conversion level. The occurrence of grafting reactions inducing covalent linkages between the polysaccharide nanofiller and the PUR acrylate matrix during the EB treatment is advanced as an explanation to account for the improvement observed in samples cured under ionizing radiation.

  13. Development of a novel oxirane-acrylate composite restorative resin material

    Science.gov (United States)

    Sripathi Panditaradhyula, Anuhya

    The need for resin with a long clinical life can be satiated through the novel formulation of varying concentrations of oxirane and acrylate monomers with an increase in filler loading in the sample, which will allow the creation of a resin that is less susceptible to chemical degradation along with improved mechanical properties. Various concentrations of oxirane and acrylate monomers with a three-component photoinitiation system, which is capable of both free radical (acrylate) and cationic (oxirane) initiation, are used. The resin composites were placed in the Speedmixer for 30 seconds and gravitation convection oven for one minute, repeated 5-7 times. The resin composites were used to create a 9.525 mm diameter * 1.5875 mm thick resin mold. The mold was then photocured for twenty seconds on both sides using VALO blue LED light. The Rockwell hardness and shore D durometer hardness served as relative measures of bonding between the monomers. The ideal formulation of oxirane and acrylate concentrations were used to perform the Instron 3 point bend test, as well as contact angle determination. The goal is to identify a resin with a clinical life twice that of the resins being used in practice. Potential findings include ideal oxirane and acrylate concentrations with the highest shore D durometer hardness, Rockwell hardness, contact angle values, and Instron 3 point bend test values. Ideal color, transparency and properties of the resin are taken into account. Optimization of oxirane and acrylate monomers, impact while using various filler components (salination, number of fillers), filler particle size variations and variations in using different filler concentrations are observed. Results of using micro and nano-sized monomers are also studied. Addition of fluorinated acrylate monomer to the micro and nano composite was the next goal. A comparison of all the above stated compositions to the control group 70/30 BisTEG was done. A study on the degradation behavior

  14. LENSING NOISE IN MILLIMETER-WAVE GALAXY CLUSTER SURVEYS

    International Nuclear Information System (INIS)

    Hezaveh, Yashar; Vanderlinde, Keith; Holder, Gilbert; De Haan, Tijmen

    2013-01-01

    We study the effects of gravitational lensing by galaxy clusters of the background of dusty star-forming galaxies (DSFGs) and the cosmic microwave background (CMB), and examine the implications for Sunyaev-Zel'dovich-based (SZ) galaxy cluster surveys. At the locations of galaxy clusters, gravitational lensing modifies the probability distribution of the background flux of the DSFGs as well as the CMB. We find that, in the case of a single-frequency 150 GHz survey, lensing of DSFGs leads both to a slight increase (∼10%) in detected cluster number counts (due to a ∼50% increase in the variance of the DSFG background, and hence an increased Eddington bias) and a rare (occurring in ∼2% of clusters) 'filling-in' of SZ cluster signals by bright strongly lensed background sources. Lensing of the CMB leads to a ∼55% reduction in CMB power at the location of massive galaxy clusters in a spatially matched single-frequency filter, leading to a net decrease in detected cluster number counts. We find that the increase in DSFG power and decrease in CMB power due to lensing at cluster locations largely cancel, such that the net effect on cluster number counts for current SZ surveys is subdominant to Poisson errors

  15. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Science.gov (United States)

    2010-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

  16. Alkyd-acrylic hybrid systems for use as binders in waterborne paints

    NARCIS (Netherlands)

    Nabuurs, T.; Baijards, R.A.; German, A.L.

    1994-01-01

    Alkyd-acrylic hybrids were prepd. by polymg. the acrylic monomers in the presence of colloidal alkyd droplets. Polymn. in the presence of alkyd caused a retardation of the polymn. through radical delocalization following radical transfer to the unsatd. groups of the fatty acids in the alkyd. The

  17. Intraocular gnathostomiasis: report of a case and review of literature.

    Science.gov (United States)

    Pillai, Gopal S; Kumar, Anil; Radhakrishnan, Natasha; Maniyelil, Jayasree; Shafi, Tufela; Dinesh, Kavitha R; Karim, Shamsul

    2012-04-01

    Intraocular gnathostomiasis is a rare parasitic infection caused by the third-stage larvae of spiruroid nematode Gnanthostoma spp. seen mostly in tropical and subtropical regions. It is a food-borne zoonosis caused by ingestion of raw or undercooked freshwater fish, amphibians, reptiles, birds, and mammals, all of which are known to harbor advanced third-stage larvae of Gnanthostoma spp. To date, 74 cases of intraocular gnathostomiasis have been reported from 12 different countries. Only four countries have reported more than 10 cases each, and India shares the rare distinction of being one of them, with 14 cases. Surprisingly, not a single case of cutaneous gnanthostomiasis has ever been reported from India. We present one such case of intraocular gnathostomiasis in a 41-year-old male who presented with an actively motile worm attached to the iris, and we review the pertinent literature of all such cases reported from India.

  18. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Klint, K.E.S.; Nilsson, B.

    2012-01-01

    Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...

  19. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    OpenAIRE

    Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

    2014-01-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermog...

  20. Sutureless Intrascleral Fixated Intraocular Lens Implantation.

    Science.gov (United States)

    Karadag, Remzi; Celik, Haci Ugur; Bayramlar, Huseyin; Rapuano, Christopher J

    2016-08-01

    To review sutureless intrascleral intraocular lens (IOL) fixation methods. Review of published literature. Sutureless intrascleral IOL fixation methods are newer and have been developed to eliminate the suture-related complications of sutured scleral fixation methods such as suture-induced inflammation or infection and IOL dislocation or subluxation due to suture degradation or suture breakage. Sutureless intrascleral fixation methods aim for intrascleral haptic fixation to achieve stability of the IOL. Various methods of sutureless scleral fixation have been described. Using a needle, a blade, or a trochar, sclerostomies are created in all techniques for intraocular access. Some surgeons prefer to create scleral tunnels, whereas others use scleral flaps for scleral fixation of haptics. The stability of IOLs is attained by the scar tissue formed around the haptics. Short-term results of these new methods are acceptable; studies including more cases with longer follow-up are needed to determine their long-term success. [J Cataract Refract Surg. 2016;32(9):586-597.]. Copyright 2016, SLACK Incorporated.