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Sample records for acrylic intraocular lenses

  1. Laboratory analyses of two explanted hydrophobic acrylic intraocular lenses

    Directory of Open Access Journals (Sweden)

    Yunhai Dai

    2014-01-01

    Full Text Available Two three-piece hydrophobic acrylic intraocular lenses (IOLs were explanted from two patients at 7 and 9 years, respectively, after implantation, because of poor fundus visualisation and/or a clinically significant decrease in visual acuity related to their opacified IOLs. In addition to light microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, confocal laser scanning microscopy was used for the first time to observe the explanted IOLs. The clinical aspect seemed to correspond to the phenomenon of surface light scattering, while laboratory analyses showed dense glistenings in the central layer of the IOL optic, which had no change next to the surface. Further studies on these phenomena are needed.

  2. Evaluation of in vitro glistening formation in hydrophobic acrylic intraocular lenses

    OpenAIRE

    Thomes BE; Callaghan TA

    2013-01-01

    Brett E Thomes, Thomas A CallaghanAlcon Research Ltd (A Novartis Company), Fort Worth, TX, USAPurpose: To evaluate the impact of continuous manufacturing process improvements on glistening formation in AcrySof hydrophobic acrylic intraocular lenses (IOLs) by comparing lenses manufactured in 2003 with lenses manufactured in 2012.Methods: Glistenings were experimentally created as aqueous-filled microvacuoles utilizing an accelerated laboratory method by immersing the lens in water at 45&de...

  3. Findings of an experimental study in a rabbit model on posterior capsule opacification after implantation of hydrophobic acrylic and hydrophilic acrylic intraocular lenses

    Directory of Open Access Journals (Sweden)

    Nikolaos Trakos

    2009-01-01

    Full Text Available Nikolaos Trakos1, Elli Ioachim2, Elena Tsanou2, Miltiadis Aspiotis1, Konstantinos Psilas1, Chris Kalogeropoulos11University Eye Clinic of Ioannina, Ioannina, Greece; 2Pathology Department, University of Ioannina, Ioannina, GreecePurpose: Study on cell growth on the posterior capsule after implantation of hydrophobic acrylic (Acrysof SA 60 AT and hydrophilic acrylic (Akreos Disc intraocular lenses (IOL in a rabbit model and comparison of posterior capsule opacification (PCO.Methods: Phacoemulsification was performed in 22 rabbit eyes, and two different IOL types (Acrysof SA60 AT and Akreos Disc were implanted. These IOLs had the same optic geometry (square edged but different material and design. Central PCO (CPCO, peripheral PCO (PPCO, Sommering’s ring (SR formation, type of growth, extension of PCO, cell type, inhibition, and fibrosis were evaluated three weeks after surgery. Histological sections of each globe were prepared to document the evaluation of PCO.Results: No statistically significant difference was observed between a hydrophobic acrylic IOL and a hydrophilic acrylic IOL in relation to the CPCO, PPCO, type of growth, extension, cell type, inhibition, and fibrosis. Statistically significant difference was observed in relation to the formation of SR with Acrysof SA 60 AT group presenting more SR than Akreos Disc group.Conclusion: PCO was not influenced by the material of the IOL or the design of the haptics of the IOLs we studied.Keywords: posterior capsule opacification, intraocular lenses, rabbit model

  4. Surface modification of acrylate intraocular lenses with dielectric barrier discharge plasma at atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    WANG Yao; LIU ZhenMei; XU ZhiKang; YAO Ke

    2009-01-01

    Surface modification with dielectric barrier discharge (DBD) plasma was carried out at atmospheric pressure (argon as the discharge gas) to improve the biocompatibility of hydrophobic acrylate intraocular lens (IOL). Changes of the plasma-treated IOL surface in chemical composition,morphology and hydrophilicity were comprehensively evaluated by X-ray photoelectron spectroscopy (XPS),field emission scanning electron microscopy (FESEM),atomic force microscopy (AFM) and water contact angle (WCA) measurements. The surface biocompatibility of the untreated and plasma-treated IOLs was compared with the adhesion behavior of platelets,macrophages and lens epithelial cells (LECs) in vitro. After DBD plasma treatment,the hydrophilicity of the IOL surface was obviously improved. The changes in WCA with treatment extension may be attributed to both the introduction of oxygen or/and nitrogen-containing polar groups and the increase of surface roughness induced by plasma etching effect. The existence of low molecular weight oxidized material (LMWOM) was proved on the plasma treated IOL which was caused by the chain scission effect of the plasma treatment. The plasma-treated lOLs resisted the adhesion of platelets and macrophages significantly. The LECs spreading and proliferation were postponed on the lOLs plasma-treated for more than 180 s,with a well maintained epithelial phenotype of LECs. The IOL biocompatibility was improved after the DBD plasma treatment. We speculate that slighter foreign-body reaction and later incidence of anterior capsule opacification (ACO) may be expected after implantation of the argon DBD plasma-treated IOL.

  5. Surface modification of acrylate intraocular lenses with dielectric barrier discharge plasma at atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Surface modification with dielectric barrier discharge(DBD) plasma was carried out at atmospheric pressure(argon as the discharge gas) to improve the biocompatibility of hydrophobic acrylate intraocular lens(IOL).Changes of the plasma-treated IOL surface in chemical composition,morphology and hydrophilicity were comprehensively evaluated by X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM) and water contact angle(WCA) measurements.The surface biocompatibility of the untreated and plasma-treated IOLs was compared with the adhesion behavior of platelets,macrophages and lens epithelial cells(LECs) in vitro.After DBD plasma treatment,the hydrophilicity of the IOL surface was obviously improved.The changes in WCA with treatment extension may be attributed to both the introduction of oxygen or/and nitrogen-containing polar groups and the increase of surface roughness induced by plasma etching effect.The existence of low molecular weight oxidized material(LMWOM) was proved on the plasma-treated IOL which was caused by the chain scission effect of the plasma treatment.The plasma-treated IOLs resisted the adhesion of platelets and macrophages significantly.The LECs spreading and proliferation were postponed on the IOLs plasma-treated for more than 180 s,with a well maintained epithelial phenotype of LECs.The IOL biocompatibility was improved after the DBD plasma treatment.We speculate that slighter foreign-body reaction and later incidence of anterior capsule opacification(ACO) may be expected after implantation of the argon DBD plasma-treated IOL.

  6. Late opacification of a hydrophilic acrylic intraocular lens

    Directory of Open Access Journals (Sweden)

    Al-Bdour Muawyah

    2008-01-01

    Full Text Available Cataract extraction and intraocular lens implantation is considered to be a safe procedure in most cases. However, the new advances in the surgical technique namely phacoemulsification and hence the increased use of foldable intraocular lenses have given rise to new complications including late opacification of intraocular lenses. In this case we report late opacification of a foldable hydrophilic acrylic intraocular lens and the surgical technique for its exchange.

  7. Surface Modification of Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Qi Huang

    2016-01-01

    Full Text Available Objective: This paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs. Data Sources: All articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect. Study Selection: The articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded. Results: Technology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol, polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO 2 , heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments. Conclusion: The surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs.

  8. Surface Modification of Intraocular Lenses

    Institute of Scientific and Technical Information of China (English)

    Qi Huang; George Pak-Man Cheng; Kin Chiu; Gui-Qin Wang

    2016-01-01

    Objective:This paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs).Data Sources:All articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect.Study Selection:The articles on the surface modification of IOLs were included,but those on design modification and surface coating were excluded.Results:Technology of surface modification included plasma,ion beam,layer-by-layer self-assembly,ultraviolet radiation,and ozone.The main molecules introduced into IOLs surface were poly (ethylene glycol),polyhedral oligomeric silsesquioxane,2-methacryloyloxyethyl phosphorylcholine,TiO2,heparin,F-heparin,titanium,titanium nitride,vinyl pyrrolidone,and inhibitors of cytokines.The surface modification either resulted in a more hydrophobic lens,a more hydrophilic lens,or a lens with a hydrophilic anterior and hydrophobic posterior surface.Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments.Conclusion:The surface modification is an efficient,convenient,economic and promising method to improve the biocompatibility ofIOLs.

  9. Adherence of Staphylococcus epidermidis to intraocular lenses.

    OpenAIRE

    Griffiths, P G; Elliot, T. S.; McTaggart, L

    1989-01-01

    We have demonstrated, with an in vitro model, that Staphylococcus epidermidis is able to colonise intraocular lenses. Adherent organisms were quantitated by light microscopy, scanning electron microscopy, and viable counting. Bacterial adherence was associated with production of a polysaccharide glycocalyx. Organisms which were attached to the lenses were resistant to apparently bactericidal concentrations of antibiotics, as determined by conventional testing. We speculate on the role of colo...

  10. Effect of four different intraocular lenses on posterior capsule opacification

    Institute of Scientific and Technical Information of China (English)

    Rahmi; Duman; Fatih; Karel; Pelin; ?zyol; Can; Ates

    2015-01-01

    AIM: To evaluate the impact of 4 different intraocular lenses(IOLs) on posterior capsule opacification(PCO) by comparing the neodymium: yttrium-aluminum-garnet(Nd:YAG) laser capsulotomy rates.METHODS: This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies.· RESULTS: An Nd:YAG laser posterior capsulotomy was performed in 153(3.07%) of the 4970 eyes. The mean follow-up time was 84 mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1-and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared.· CONCLUSION: In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design(1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate.

  11. File list: DNS.Oth.20.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  15. Drug-Eluting Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Angel Concheiro

    2011-11-01

    Full Text Available Notable advances in materials science and in surgical techniques make the management of cataract by replacement of the opaque crystalline with an intraocular lens (IOL, one of the most cost-effective interventions in current healthcare. The usefulness and safety of IOLs can be enhanced if they are endowed with the ability to load and to sustain drug release in the implantation site. Drug-eluting IOLs can prevent infections and untoward reactions of eye tissues (which lead to opacification and also can act as drug depots for treatment of several other ocular pathologies. Such a myriad of therapeutic possibilities has prompted the design of drug-IOL combination products. Several approaches are under study, namely combination of the IOL with an insert in a single device, soaking in drug solutions, impregnation using supercritical fluids, coating with drug/polymer layers, and covalent grafting of the drug. The advantages/limitations of each technique are discussed in the present review on selected examples. Although more in vivo data are required, the information already available proves the interest of some approaches in ocular therapeutics.

  16. 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

  17. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    OpenAIRE

    Ladan Espandar; Shameema Sikder; Majid Moshirfar

    2011-01-01

    Ladan Espandar1, Shameema Sikder2, Majid Moshirfar31Department of Ophthalmology, Tulane University, New Orleans, LA, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 3John A Moran Eye Center, University of Utah, Salt Lake City, UT, USAAbstract: Intraocular lens development is driven by higher patient expectations for ideal visual outcomes. The recently US Food and Drug Administration-approved Softec HD™ lens is an aspheric, hydrophilic acrylic intraocular le...

  18. Development of a hydrophobic polymer composition with improved biocompatibility for making foldable intraocular lenses

    Science.gov (United States)

    Haldar, R. S.; Chauhan, R.; Kapoor, K.; Niyogi, U. K.

    2014-05-01

    A hydrophobic composition for foldable intraocular lenses was developed by copolymerizing phenyl ethyl acrylate, phenyl ethyl methacrylate and butanediol diacrylate by gamma irradiation. Aqueous solution of heparin, a biocompatibilizer absorbed in hydroxyethyl methacrylate was added to the monomer mixture before irradiation to impart desired level of hydrophilicity and improved biocompatibility to the hydrophobic composition. Ketorolac tromethamine, an anti-inflammatory agent and L-glutathione, an antioxidant were added to the composition as functional additive for exhibiting improved performance while in use. Concentrations of monomers, biocompatibilizer and functional additives were optimized to develop an advanced material for foldable intraocular lenses. Transmittance, refractive index, Abbe number, hardness, tensile strength, flexibility and foldability were studied on the final composition. Scanning electron microscopic study, differential scanning calorimetric analysis, leachability and viscometry confirmed the permanent incorporation of additives into the polymer. Results of haemocompatibility, tissue implantation and cytotoxicity confirm that the biocompatibility of the base polymer was improved by incorporation of heparin.

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  20. NEW MATERIAL FOR LOW-COST INTRAOCULAR LENSES

    NARCIS (Netherlands)

    JONGEBLOED, WL; VANDERVEEN, G; KALICHARAN, D; VANANDEL, MV; BARTMAN, G; WORST, JGF

    1994-01-01

    A UV-hardening lacquer material based on polyurethane, used in Philips compact disc lens systems, was tested as suitable material for low-cost intraocular lenses (IOLs). A slightly changed composition (code number I-0.5A) came out as the best and was subsequenly tested, with reference to poly(methyl

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Comparison of visual performance of multifocal intraocular lenses with same material monofocal intraocular lenses.

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    Tomofusa Yamauchi

    Full Text Available PURPOSE: To compare the visual performance of multifocal intraocular lenses (IOLs and monofocal IOLs made of the same material. METHODS: The subjects included patients implanted with either Tecnis® monofocal IOLs (ZA9003 or ZCB00 or Tecnis® multifocal IOLs (ZMA00 or ZMB00 bilaterally. We conducted a retrospective study comparing the two types of IOLs. The multifocal group included 46 patients who were implanted with Tecnis® multifocal IOLs bilaterally. The monofocal group was an age- and sex-matched control group, and included 85 patients who were implanted with Tecnis® monofocal IOLs bilaterally. Lens opacity grading, the radius of corneal curvature, corneal astigmatism, axial length and the refractive status were measured preoperatively. Pupil size, ocular aberrometry, distance, intermediate and near visual acuity, contrast sensitivity with and without glare and the responses to a quality-of-vision questionnaire were evaluated pre- and postoperatively. RESULTS: The uncorrected near visual acuity was significantly better in the multifocal group, whereas both the corrected intermediate and near visual acuity were better in the monofocal group. Contrast sensitivity (with and without glare was significantly better in the monofocal group. The rate of spectacle dependency was significantly lower in the multifocal group. There were no significant differences between the two groups regarding most items of the postoperative quality-of-vision questionnaire (VFQ-25, with the exception that the patients in the monofocal group reported fewer problems with nighttime driving. CONCLUSIONS: The multifocal IOLs used in this study reduced spectacle dependency more so than monofocal IOLs and did not compromise the subjective visual function, with the exception of nighttime driving.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  4. 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.

  5. New two-point scleral-fixation technique for foldable intraocular lenses with four hollow haptics.

    Science.gov (United States)

    Liu, He-Ting; Jiang, Zheng-Xuan; Tao, Li-Ming

    2016-01-01

    The study was to report a new two-point scleral-fixation technique for foldable intraocular lenses with four haptics. Lenses were slid into the anterior chamber from a 2.8 mm corneal incision and fixed under two sclera flaps at two opposite points. The postoperative best-corrected visual acuities (BCVAs) of all patients were significantly better than their preoperative BCVA. The results demonstrate that two-point, scleral fixations of foldable, intraocular lenses might be practicable and effective.

  6. 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.

  7. Psychophysical Vision Simulation of Diffractive Bifocal and Trifocal Intraocular Lenses

    Science.gov (United States)

    Brezna, Wolfgang; Lux, Kirsten; Dragostinoff, Nikolaus; Krutzler, Christian; Plank, Nicole; Tobisch, Rainer; Boltz, Agnes; Garhöfer, Gerhard; Told, Reinhard; Witkowska, Katarzyna; Schmetterer, Leopold

    2016-01-01

    Purpose The visual performance of monofocal, bifocal, and trifocal intraocular lenses was evaluated by human individuals using a vision simulator device. This allowed investigation of the visual impression after cataract surgery, without the need actually to implant the lenses. Methods The randomized, double-masked, three-way cross-over study was conducted on 60 healthy male and female subjects aged between 18 and 35 years. Visual acuity (Early Treatment Diabetic Retinopathy Study; ETDRS) and contrast sensitivity tests (Pelli-Robson) under different lighting conditions (luminosities from 0.14–55 cd/m2, mesopic to photopic) were performed at different distances. Results Visual acuity tests showed no difference for corrected distance visual acuity data of bi- and trifocal lens prototypes (P = 0.851), but better results for the trifocal than for the bifocal lenses at distance corrected intermediate (P = 0.021) and distance corrected near visual acuity (P = 0.044). Contrast sensitivity showed no differences between bifocal and trifocal lenses at the distant (P = 0.984) and at the near position (P = 0.925), but better results for the trifocal lens at the intermediate position (P = 0.043). Visual acuity and contrast sensitivity showed a strong dependence on luminosity (P < 0.001). Conclusions At all investigated distances and all lighting conditions, the trifocal lens prototype often performed better, but never worse than the bifocal lens prototype. Translational Relevance The vision simulator can fill the gap between preclinical lens development and implantation studies by providing information of the perceived vision quality after cataract surgery without implantation. This can reduce implantation risks and promotes the development of new lens concepts due to the cost effective test procedure. PMID:27777828

  8. [To guard against mistakes in selection of intraocular lenses].

    Science.gov (United States)

    He, Shou-zhi

    2008-04-01

    Development of different kinds of new intraocular lenses (IOL) provide more selections to meet various clinical requirements, which may plays an active role in making cataract surgery more perfectible. But there are many misunderstandings about how to select the proper IOL. For example, "the expensive one is the best one", "new product is absolutely perfect", and so on. Some surgeons prefer more practice and ignore the summary of the experiences. Someone unilaterally exaggerates some special function of IOL When selecting the IOL, it is a common challenge for us to fully consider the patients needs, and properly manage the relationship between the basic need and special need, and to avoid fanaticism, and provide the best benefits to the patients. PMID:18844010

  9. Extracapsular cataract extraction : the fate of retained lens material and intraocular lenses

    NARCIS (Netherlands)

    J.P. Kappelhof (Johan)

    1987-01-01

    textabstractThe aim of this study was to examine the fate of the lens material that remains in the eye after an extracapsular cataract extraction both with and without insertion of an intraocular lens. Apart from this, the development of precipitates on the intraocular lenses was morphologically inv

  10. Surgical management of astigmatism with toric intraocular lenses

    Directory of Open Access Journals (Sweden)

    Bruna V. Ventura

    2014-04-01

    Full Text Available Correction of corneal astigmatism is a key element of cataract surgery, since post-surgical residual astigmatism can compromise the patient's uncorrected visual acuity. Toric intraocular lenses (IOLs compensate for corneal astigmatism at the time of surgery, correcting ocular astigmatism. They are a predictable treatment. However, accurate measurement of corneal astigmatism is mandatory for choosing the correct toric IOL power and for planning optimal alignment. When calculating the power of toric IOLs, it is important to consider anterior and posterior corneal astigmatism, along with the surgically induced astigmatism. Accurate toric lens alignment along the calculated meridian is also crucial to achieve effective astigmatism correction. There are several techniques to guide IOL alignment, including the traditional manual marking technique and automated systems based on anatomic and topographic landmarks. The aim of this review is to provide an overview on astigmatism management with toric IOLs, including relevant patient selection criteria, corneal astigmatism measurement, toric IOL power calculation, toric IOL alignment, clinical outcomes and complications.

  11. Surface modification of intraocular lenses to reduce corneal endothelial damage.

    Science.gov (United States)

    Knight, P M; Link, W J

    1979-04-01

    Two methods of surface modification of PMMA, permanent and temporary, were investigated for use on intraocular lenses to reduce corneal endothelial damage due to corneal-IOL touch. Monomer grafting using gamma irradiation was found to produce permanently hydrophilic surfaces. Temporary surface modifications developed and tested were peelable and dissolvable coatings. Test samples were touched to freshly excised rabbit corneas to evaluate the effectiveness of the various surface modifications in reducing endothelial cell damage. This touch testing was performed using static testing in which the test sample was touched to the cornea without movement and dynamic testing in which there was relative movement between the cornea and the test sample. While unmodified PMMA did significant cell damage in both static and dynamic tests perpamently modified (hydrophilic grafted) surfaces were found to perform well in the static, but not in the dynamic tests. Dissolvable coatings performed well in both tests, even with very thin coatings. There was little differentiation between the various water-soluble coatings tested. Due to its characteristics and rate of dissolution, polyvinyl alcohol appears to be an optimum material for coating IOLs. A series of in vitro and in vivo tests performed to assess its safety indicate that PVA is nontoxic and safe in animal eyes. PMID:479004

  12. Quality of vision through diffractive bifocal intraocular lenses.

    OpenAIRE

    Jay, J L; Chakrabarti, H S; Morrison, J D

    1991-01-01

    Two elderly women have each received a monofocal intraocular lens in one eye and a 3M diffractive bifocal intraocular lens in the other eye. Both eyes were shown to have equivalent retinal/neural function by measuring contrast sensitivity to laser interference fringes which bypassed refractive and other defects of the ocular media. The eyes with a bifocal intraocular lens displayed a much greater depth of focus, though at the expense of diminished contrast sensitivity compared with the normal...

  13. 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.

  14. Drug loading of foldable commercial intraocular lenses using supercritical impregnation.

    Science.gov (United States)

    Bouledjouidja, A; Masmoudi, Y; Sergent, M; Trivedi, V; Meniai, A; Badens, E

    2016-03-16

    The drug delivery through intraocular lenses (IOLs) allows the combination of cataract surgery act and postoperative treatment in a single procedure. In order to prepare such systems, "clean" supercritical CO2 processes are studied for loading commercial IOLs with ophthalmic drugs. Ciprofloxacin (CIP, an antibiotic) and dexamethasone 21-phosphate disodium (DXP, an anti-inflammatory drug) were impregnated into foldable IOLs made from poly-2-hydroxyethyl methacrylate (P-HEMA). A first pre-treatment step was conducted in order to remove absorbed conditioning physiological solution. Supercritical impregnations were then performed by varying the experimental conditions. In order to obtain transparent IOLs and avoid the appearance of undesirable foaming, it was necessary to couple slow pressurization and depressurization phases during supercritical treatments. The impregnation yields were determined through drug release studies. For both drugs, release studies show deep and reproducible impregnation for different diopters. For the system P-HEMA/CIP, a series of impregnations was performed to delimit the experimental range at two pressures (80 and 200 bar) in the presence or absence of ethanol as a co-solvent for two diopters (+5.0 D and +21.0 D). Increase in pressure in the absence of a co-solvent resulted in improved CIP impregnation. The addition of ethanol (5 mol%) produced impregnation yields comparable to those obtained at 200 bar without co-solvent. A response surface methodology based on experimental designs was used to study the influence of operating conditions on impregnation of IOLs (+21.0 D) in the absence of co-solvent. Two input variables with 5 levels each were considered; the pressure (80-200 bar) and the impregnation duration (30-240 min). CIP impregnation yields ranging between 0.92 and 3.83 μg CIP/mg IOL were obtained from these experiments and response surface indicated the pressure as a key factor in the process. The DXP impregnation in P-HEMA was

  15. Haptic Breakage after Transscleral Fixation of a Single-Piece Acrylic Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Hiroki Tanaka

    2014-07-01

    Full Text Available Purpose: To report the case of a patient with a damaged haptic of an acrylic intraocular lens (IOL after transscleral IOL fixation. Methods: This is a retrospective and descriptive case report. Results: A 40-year-old man presented with sudden visual loss in the left eye. He had undergone phacoemulsification/aspiration and IOL implantation 3 years previously and IOL repositioning with transscleral fixation 2 years before the initial visit. His visual acuity was 0.3 in the left eye due to corneal edema caused by a foreign body, i.e., the severed haptic tip of the single-piece acrylic IOL, which was surgically removed. The IOL itself was tilted and therefore explanted. The surface of the tip of the haptic suggested that the monofilament suture thread had exerted continuous force across the haptic. Conclusions: The haptics of acrylic IOLs can be damaged after transscleral fixation.

  16. Clinical comparison of the optical performance of aspheric and spherical intraocular lenses

    NARCIS (Netherlands)

    van Gaalen, Kim W.; Koopmans, Steven A.; Jansonius, Nomdo M.; Kooijman, Aart C.

    2010-01-01

    PURPOSE: To compare the optical performance of aspheric Tecnis ZA9003 and spherical Sensar AR40e intraocular lenses (IOLs). SETTING: Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. METHODS: An aspheric IOL was implan

  17. Surface characterization of polymer-drug modified vascular stents and intraocular lenses

    Science.gov (United States)

    Elachchabi, Amin

    human coronary smooth muscle cell growth in vitro whereas dexamethasone exhibited no similar effect. A second major subject of this research was a series of studies concerning the properties of foldable hydrophobic acrylic intraocular lenses (IOLs) which have not previously been investigated. Most IOLs implanted today in the U.S. and the western world are foldable. The goal of this research was to conduct new surface characterization studies on the surfaces of several different foldable lenses in clinical use. Atomic force microscopy showed that these IOLs have different morphologies and that hydration greatly altered the surface morphology of these implants. Contact angle goniometry studies indicated that water contact angles varied significantly from one lens to the other and that prolonged hydration led to a reduction of the water contact angle. Nanoindentation experiments yielded new information on the surface mechanical properties of IOLs and a new methodology was developed to analyze nanoindent data to determine the surface modulus and hardness of foldable IOLs and low modulus polymers in general. The novel surface properties studies reported here can be important in guiding the design and the development of new ocular implants.

  18. Method for in vitro assessment of straylight from intraocular lenses

    NARCIS (Netherlands)

    Łabuz, Grzegorz; Vargas-Martín, Fernando; van den Berg, Thomas J T P; López-Gil, Norberto

    2015-01-01

    Ocular straylight has been measured by means of psychophysical methods over the years. This approach gives a functional parameter yielding a straight comparison with optically defined light scattering, and the point-spread-function. This is of particular importance when the effect of intraocular len

  19. 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.

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

    OpenAIRE

    Wong, S Chien; Ramkissoon, Yashin D; Lopez, Mauricio; Page, Kristopher; Ivan P. Parkin; 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...

  1. Straylight Measurements in Two Different Apodized Diffractive Multifocal Intraocular Lenses

    NARCIS (Netherlands)

    Lapid-Gortzak, Ruth; Labuz, Grzegorz; van der Meulen, Ivanka J; van der Linden, Jan Willem; Mourits, M P; van den Berg, Tom J

    2015-01-01

    PURPOSE: To evaluate differences in straylight between eyes implanted with a hydrophilic multifocal IOL (Seelens MF; Hanita Lenses, Hanita, Israel) and a hydrophobic multifocal IOL (SN6AD1; Alcon Laboratories, Inc., Fort Worth, TX). METHODS: In a prospective cohort study, routinely obtained straylig

  2. Comparisons of amplitude of pseudoaccommodation with aspheric yellow, spheric yellow, and spheric clear monofocal intraocular lenses

    OpenAIRE

    Nishi T.; Taketani F; Ueda T; Ogata N.

    2013-01-01

    Tomo Nishi, Futoshi Taketani, Tetsuo Ueda, Nahoko Ogata Department of Ophthalmology, Nara Medical University, Kashihara City, Nara, Japan Purpose: To determine the amplitude of pseudoaccommodation and higher-order aberrations with three types of implanted monofocal intraocular lenses (IOLs): aspheric yellow (IQ); spheric yellow (NT); and spheric clear (AT). Setting: Department of Ophthalmology, Nara Medical University, Nara, Japan. Methods: We studied 60 patients who underwent small incision...

  3. Evaluation of actual retinal images produced by misaligned aspheric intraocular lenses in a model eye

    OpenAIRE

    Fujikado, Takashi

    2014-01-01

    Takashi Fujikado,1 Makoto Saika2 1Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan; 2Research and Development Department of Topcon Corporation, Tokyo, Japan Purpose: To examine the effect of misalignment (decentration and tilt) of intraocular lenses (IOLs) on retinal image quality using a water-immersed model eye with corneal spherical aberration adjusted to the values found in normal human eyes (spherical aberration 0.25 µm; pupil d...

  4. 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...... evaluated as surgical complications and residual astigmatism. CLINICAL RELEVANCE: Postoperative astigmatism is an important cause of suboptimal UCDVA and need for distance spectacles. Toric IOLs may correct for preexisting corneal astigmatism at the time of surgery. METHODS: We performed a systematic...

  5. 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.

  6. Sulcus Fixation of Foldable Intraocular Lenses Guided by Ultrasound Biomicroscopy.

    Science.gov (United States)

    Gao, Shasha; Qin, Tingyu; Wang, Shengnan; Lu, Yong

    2015-01-01

    Background. To evaluate the clinical efficacy of suture fixation of foldable intraocular lens (IOL) in ciliary sulcus guided by ultrasound biomicroscopy (UBM). Methods. Thirty-five eyes of 32 cases needing suture fixation of foldable IOL in ciliary sulcus in our hospital were collected and divided into two groups: group A and group B. In group A, UBM was performed on 19 eyes of 17 cases before surgery to locate the projection position of ciliary sulcus in iris surface. In group B, the traditional sulcus fixation of IOL was performed on 16 eyes of 15 cases. The inserting position of needles, the haptics position of IOL and the IOL tilt, and decentration were observed by UBM examination 3 months after the surgery. Meanwhile, the vision and contrast sensitivity were analysed. Results. The differences in inserting position of the needle, the IOL tilt and decentration, the ratio of IOL haptics in sulcus, and uncorrected visual acuity were statistically significant (P 0.05). Conclusions. Sulcus fixation of foldable IOL aided by UBM can increase the accuracy of IOL haptics implanted into ciliary sulcus and reduce the IOL tilt and decentration.

  7. Sulcus Fixation of Foldable Intraocular Lenses Guided by Ultrasound Biomicroscopy

    Directory of Open Access Journals (Sweden)

    Shasha Gao

    2015-01-01

    Full Text Available Background. To evaluate the clinical efficacy of suture fixation of foldable intraocular lens (IOL in ciliary sulcus guided by ultrasound biomicroscopy (UBM. Methods. Thirty-five eyes of 32 cases needing suture fixation of foldable IOL in ciliary sulcus in our hospital were collected and divided into two groups: group A and group B. In group A, UBM was performed on 19 eyes of 17 cases before surgery to locate the projection position of ciliary sulcus in iris surface. In group B, the traditional sulcus fixation of IOL was performed on 16 eyes of 15 cases. The inserting position of needles, the haptics position of IOL and the IOL tilt, and decentration were observed by UBM examination 3 months after the surgery. Meanwhile, the vision and contrast sensitivity were analysed. Results. The differences in inserting position of the needle, the IOL tilt and decentration, the ratio of IOL haptics in sulcus, and uncorrected visual acuity were statistically significant (P0.05. Conclusions. Sulcus fixation of foldable IOL aided by UBM can increase the accuracy of IOL haptics implanted into ciliary sulcus and reduce the IOL tilt and decentration.

  8. 三种非球面单焦点丙烯酸酯人工晶状体植入术后视觉质量的临床观察%Clinical observation on visual function in patients implanted three kinds of aspheric acrylic monofocal intraocular lenses

    Institute of Scientific and Technical Information of China (English)

    冀海轮; 肖伟; 赵芳; 赵岱新; 濮伟

    2013-01-01

    Objective To evaluate best corrected visual acuity(BCVA) and contrast sensitivity(CS) under photopic condition with no glare in patients following implantation of three different kinds of aspheric acrylic monofocal intraocular lens. Methods 77 cases(90 eyes) of age-related cataract patients were selected,who were undergone phacoemulsification and intraocular lens(IOL) implantation in our hospital during December 2011 to November 2012. Preoperatively, the patients were randomly divided into three groups. Group 1 including 30 eyes(25 cases) were implanted with hydrophobic yellow-tinted acrylic IOLs; Group 2(30 eyes of 28 cases) with hydrophilic acrylic IOLs;Group 3(30 eyes of 24 cases) with hydrophilic acrylic surface heparin processing IOLs. All eyes were evaluated at 1 month and 3 months postoperatively. The BCVA and CS under photopic 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 contrast sensitivity results (after standardization of contrast sensitivity value: lgCS)(P>0.05) between groups. Conclusions There were not marked differences of BCVA and CS between groups of patients at the follow-up intervals of 1 month and 3 months. The blue-filter type artificial lens protect the retina, thus, it is advisable to implant yellow-tinted filter blue artificial lens.%目的:研究三种非球面丙烯酸酯人工晶状体植入术后患者在最佳矫正视力及明视下对比敏感度(contrast sensitivity,CS)的变化,评价白内障超声乳化联合单焦点非球面丙烯酸酯人工晶状体植入术后患者的视觉质量。方法选择2011年12月至2012年11月期间于我院行白内障超声乳化吸除联合人工晶状体植入术的年龄相关性白内障患者77例(90眼)。术前将患者随机分成三组:A组(25例,30眼)植入疏水性染黄色

  9. Hydrophilic Acrylic Intraocular Lens Opacification after Descemet Stripping Automated Endothelial Keratoplasty

    Science.gov (United States)

    Norouzpour, Amir; Zarei-Ghanavati, Siamak

    2016-01-01

    Purpose: To report hydrophilic acylic intraocular lens (IOL) opacification after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) in an eye with multiple prior intraocular surgeries and iatrogenic aniridia. Case Report: A 34-year-old woman with history of penetrating keratoplasty (PKP) for advanced keratoconus and subsequent Urrets-Zavalia Syndrome (UZS) underwent phacoemulsification and hydrophilic acrylic IOL implantation for her cataract. In order to control post-PKP glaucoma, multiple glaucoma surgeries including two glaucoma drainage implants were performed. As the original corneal graft failed, the patient subsequently underwent re-PKP. Four years later, she underwent DSAEK for treatment of the second graft failure. Ten months after DSAEK, a double semi-circular pattern of IOL opacification was observed on the anterior surface of the IOL. The patient did not report any complaints and we decided not to exchange the IOL. Conclusion: In an eye with UZS and iatrogenic aniridia, IOL opacification may result from direct contact between the IOL surface and exogenous air. Aniridia can be a risk factor for development of IOL opacification after DSAEK. Further studies are required to confirm this hypothesis. PMID:27413506

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

    OpenAIRE

    Frank Schaeffel; Hakan Kaymak

    2014-01-01

    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 “recept...

  11. 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.

  12. Causes and correction of dissatisfaction after implantation of presbyopia-correcting intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gibbons A

    2016-10-01

    Full Text Available Allister Gibbons, Tayyeba K Ali, Daniel P Waren, Kendall E Donaldson Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA Purpose: The purpose of this study was to assess the causes and possible solutions for patient dissatisfaction after the implantation of presbyopia-correcting intraocular lenses (IOLs. Methods: This study was a retrospective review of clinical records. All patients who were seen between January 2009 and December 2013 whose primary reason for consultation was dissatisfaction with visual performance after presbyopia-correcting IOL implantation were included in the study. A single treating physician, who determined the most probable cause of dissatisfaction, decided which interventions to pursue following the initial consultation. Results: Data from 74 eyes of 49 patients were analyzed. The most common cause for complaint was blurry or foggy vision both for distance and near (68%. Complaints were most frequently attributed to residual refractive error (57% and dry eye (35%. The most common interventions pursued were treatment of refractive error with glasses or contact lenses (46% and treatment for dry eye (24%. Corneal laser vision correction was done in 8% of eyes; 7% required an IOL exchange. After the interventions, 45% of patients had completed resolution of symptoms, 23% of patients were partially satisfied with the results, and 32% remained completely dissatisfied with the final results. Conclusion: The most identifiable causes of dissatisfaction after presbyopia-correcting IOL implantation are residual refractive error and dry eye. Most patients can be managed with conservative treatment, though a significant number of patients remained unsatisfied despite multiple measures. Keywords: intraocular lens, cataract, presbyopia, multifocal intraocular lens

  13. Calcium-phosphate deposits on a hydrophilic acrylic intraocular lens after silicon oil tamponade

    Directory of Open Access Journals (Sweden)

    Rashid Alsaeidi

    2008-01-01

    Full Text Available We report a 52-year-old man who underwent uncomplicated cataract operation and posterior chamber lens implantation (hydrophilic acrylic lens in his left eye 5 years prior to presentation. Two years after surgery he developed pseudophakic retinal detachment which was successfully treated with pars plana vitrectomy and silicon oil tamponade. The silicon oil was removed one year after surgery. A year later he complained of increasing blurred vision in the left eye. Clinical examination revealed vesicular alterations located superficially on the intraocular lens (IOL, which could not be removed by perflourocarbon-perflourohexloctane lavage. As the patient complained about increasing visual impairment, the IOL was removed. The IOL was investigated by electronmicroscopy and biochemical analysis. During electron microscopy and following biochemical analysis the observed alterations were identified as calcium-phosphate particles located on the superficial aspect of the IOL. The occurrence of calcium-phosphate deposits on a posterior chamber IOL after silicon oil tamponade is a rare complication and has not been described so far. As these deposits interfere with visual acuity, removal of the lens has to be considered.

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

    Science.gov (United States)

    Ventura, Bruna Vieira; MacLean, Kyle Douglas; Lira, Wagner; Oliveira, Daniele Mendes de; Ventura, Camila Vieira; Werner, Liliana

    2016-01-01

    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.

  15. Comparison of Through-Focus Image Quality Across Five Presbyopia-Correcting Intraocular Lenses (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Pepose, Jay S.; Wang, Daozhi; Altmann, Griffith E.

    2011-01-01

    Purpose To assess through-focus polychromatic image sharpness of five US Food and Drug Administration–approved presbyopia-correcting intraocular lenses (IOLs) through a range of object vergences and pupil diameters utilizing an image sharpness algorithm. Methods A 1951 US Air Force resolution target was imaged through a Crystalens AO (AO) (Bausch & Lomb Surgical, Aliso Viejo, California), Crystalens HD (HD) (Bausch & Lomb Surgical, Aliso Viejo, California), aspheric ReSTOR +4.0 (R4) (Alcon Laboratories, Fort Worth, Texas), aspheric ReSTOR +3.0 (R3) (Alcon Laboratories, Fort Worth, Texas), and Tecnis Multifocal Acrylic (TMF) (Abbott Medical Optics, Irvine, California) IOL in an anatomically and optically accurate model eye and captured digitally for each combination of pupil diameter and object vergence. The sharpness of each digital image was objectively scored using a two-dimensional gradient function. Results The AO lens had the best distance image sharpness for all pupil diameters, followed by the HD. With a 5-mm pupil, the R4 lens achieved distance image quality similar to the HD, but inferior to the AO. The R3 successfully moved the near focal point farther from the patient compared to the R4, but did not improve image sharpness at intermediate distances and showed worse distance and near image sharpness. Consistent with apodization, the ReSTOR IOLs displayed better distance and poorer near image sharpness as pupil diameter increased. The TMF lens showed consistent distance and near image sharpness across pupil diameters and exhibited the best near image sharpness for all pupil diameters. Conclusions Differing IOL design strategies to increase depth of field are associated with quantifiable differences in image sharpness at varying vergences and pupil sizes. An objective comparison of the imaging properties of specific presbyopia-correcting IOLs, in conjunction with patients’ pupil sizes, can be useful in selecting the most appropriate IOL for each patient

  16. Location and composition of haptics of posterior chamber intraocular lenses. Histopathologic study of postmortem eyes.

    Science.gov (United States)

    McDonnell, P J; Champion, R; Green, W R

    1987-02-01

    Of 110 eyes with posterior chamber intraocular lenses (IOLs) examined postmortem, 37% had both haptics outside of the capsular bag; 57% had one haptic in the capsular bag and the other haptic outside of the bag. Typically, these optics were decentered by 1 to 2 mm. Only six eyes (5%) had both haptics within the capsular bag. Erosion into the ciliary sulcus produced obliteration of the major arterial circle of the iris in 12 eyes (11%). The local tissue response to eroding haptics was similar for haptics composed of polypropylene and haptics composed of polymethylmethacrylate (PMMA). The authors found considerable discrepancy between the actual location of haptics and the surgeon's desired location (i.e., capsular bag or ciliary sulcus). Most of these cases were clinically successful.

  17. One Year Follow-Up After Veriflex Phakic Intraocular Lenses Implantation for Correction of Myopia

    Science.gov (United States)

    Pjano, Melisa Ahmedbegovic; Biscevic, Alma; Grisevic, Senad; Pidro, Ajla; Ratkovic, Mirko; Bohac, Maja; Husovic, Amila Alikadic; Gojak, Refet

    2016-01-01

    Objectives: The aim of this study was to evaluate visual and refractive outcomes after Veriflex phakic intraocular lenses (pIOL) implantation in moderately myopic eyes as well as postoperative complications. Methods: This prospective clinical study included 40 eyes of 26 patients which underwent implantation of Veriflex for correction of myopia from -6.00 to -14.50 diopters (D) in the Eye Clinic Svjetlost Sarajevo, from January 2011 to January 2014. Uncorrected distance visual acuity (UDVA), manifest residual spherical equivalent (MRSE), intraocular pressure (IOP), endothelial cell (EC) density were evaluated at one, three, six and 12 months. Other complications in postoperative period were evaluated. For statistical analysis SPSS for Windows and Microsoft Excel were used. Results: Out of 26 patients 14 had binocular and 12 monocular procedure, with mean age of 29.8±6.5 years. After 12 months mean UDVA was 0.73±0.20. Mean MRSE was -0.39±0.31D and 90% of eyes had MRSE within ±1D. EC loss was 7.18±4.33%. There was no significant change of IOP by the end of 12 months follow up period. The only intraoperative complication was hyphema and occurred in one eye. Few postoperative complications were: subclinical inflammation in three eyes (7,5%), pigment dispersion in four eyes (10%), ovalisation of papilla in 2 eyes (5%) and decentration of pIOL in 2 eyes (5%). Conclusion: Implantation of iris-claw phakic lenses Veriflex for treating moderately high myopia is a procedure with good visual and refractive results and few postoperative complications. PMID:27482131

  18. Wavefront analysis and modulation transfer function of three multifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Santhiago Marcony

    2010-01-01

    Full Text Available Purpose: To evaluate wavefront performance and modulation transfer function (MTF in the human eye after the implantation of diffractive or refractive multifocal intraocular lenses (IOLs. Materials and Methods: This was a prospective, interventional, comparative, nonrandomized clinical study. Uncorrected distance and near visual acuity, and wavefront analysis including MTF curves (iTrace aberrometer, Tracey Technologies, Houston, TX, USA were measured in 60 patients after bilateral IOL implantation with 6 months of follow-up. Forty eyes received the diffractive ReSTOR (Alcon, 40 eyes received the refractive ReZoom (Advanced Medical Optics and 40 eyes, the Tecnis ZM900 (Advanced Medical Optics. The comparison of MTF and aberration between the intraocular lenses was performed using analysis of variance (ANOVA, followed by the Dunn test when necessary. Results: The mean uncorrected distance visual acuity was similar in all three groups of multifocal IOLs. The ReSTOR group provided better uncorrected near visual acuity than the ReZoom group ( P < 0.001, but similar to the Tecnis group. Spherical aberration was significantly higher in the ReZoom group ( P = 0.007. Similar MTF curves were found for the aspheric multifocal IOL Tecnis and the spheric multifocal IOL ReSTOR, and both performed better than the multifocal IOL ReZoom in a 5 mm pupil ( P < 0.001 at all spatial frequencies. Conclusions: Diffractive IOLs studied presented similar MTF curves for a 5 mm pupil diameter. Both diffractive IOLs showed similar spherical aberration, which was significantly better with the full-diffractive IOL Tecnis than with the refractive IOL ReZoom.

  19. The Relation of the Location of Haptics of Posterior Chamber Intraocular Lenses and Peripheral Anterior Synechia

    Institute of Scientific and Technical Information of China (English)

    RuiduanLiao; ShaozhenLi

    1995-01-01

    Purpose:To investigate the occurrence,outcome and influencial factors of the pe-ripheral anterior synechia(PAS)following implantation of posterior chamber in-traocular lenses for finding a way to reduce thePAS.Subjects;40 eyes of 38senile cataract patients with normal chamber angle and in-traocular pressue(IOP)preoperatively were examined.Methods:Extracapsular cataract extraction was performed under microscope with insertion of a posterior chamber lens implant vaulted anteriorly by 10°.Go-nioscopy and slit-lamp examination and photography of the operated eyes were performed 3to 6months postoperatively.Results:PAS were found in 20(50%)of the 40eyes.Among the 20eyes with PAS the locations of 23haptics in17eyes corresponded with those of the PAS.PAS were seen more frequently with vertically sulcus-fixated haptics than with the horizontally capsular-fixated haptics.showing a significant difference(P<0.05).88%of the eyes withPAS had pupillary edformation,but their visual acuities and IOP were not affected.Conclusions:PAS is more likely to occur with vertically sulcus-fixated IOL.Rotat-ing the capsular-fixated haptics to the horizontal position may reduce the inci-dence of PAS.Gonioscopy should be a routine follow-up examination.

  20. Causes and correction of dissatisfaction after implantation of presbyopia-correcting intraocular lenses

    Science.gov (United States)

    Gibbons, Allister; Ali, Tayyeba K; Waren, Daniel P; Donaldson, Kendall E

    2016-01-01

    Purpose The purpose of this study was to assess the causes and possible solutions for patient dissatisfaction after the implantation of presbyopia-correcting intraocular lenses (IOLs). Methods This study was a retrospective review of clinical records. All patients who were seen between January 2009 and December 2013 whose primary reason for consultation was dissatisfaction with visual performance after presbyopia-correcting IOL implantation were included in the study. A single treating physician, who determined the most probable cause of dissatisfaction, decided which interventions to pursue following the initial consultation. Results Data from 74 eyes of 49 patients were analyzed. The most common cause for complaint was blurry or foggy vision both for distance and near (68%). Complaints were most frequently attributed to residual refractive error (57%) and dry eye (35%). The most common interventions pursued were treatment of refractive error with glasses or contact lenses (46%) and treatment for dry eye (24%). Corneal laser vision correction was done in 8% of eyes; 7% required an IOL exchange. After the interventions, 45% of patients had completed resolution of symptoms, 23% of patients were partially satisfied with the results, and 32% remained completely dissatisfied with the final results. Conclusion The most identifiable causes of dissatisfaction after presbyopia-correcting IOL implantation are residual refractive error and dry eye. Most patients can be managed with conservative treatment, though a significant number of patients remained unsatisfied despite multiple measures. PMID:27784985

  1. Evaluation of actual retinal images produced by misaligned aspheric intraocular lenses in a model eye

    OpenAIRE

    Fujikado T; Saika M

    2014-01-01

    Takashi Fujikado,1 Makoto Saika2 1Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan; 2Research and Development Department of Topcon Corporation, Tokyo, Japan Purpose: To examine the effect of misalignment (decentration and tilt) of intraocular lenses (IOLs) on retinal image quality using a water-immersed model eye with corneal spherical aberration adjusted to the values found in normal human eyes (spherical aberration 0.25 µm; pupil diame...

  2. Toric intraocular lenses for correction of astigmatism in keratoconus and after corneal surgery

    Directory of Open Access Journals (Sweden)

    Mol IEMA

    2016-06-01

    Full Text Available Ilse EMA Mol,1,2 Bart TH Van Dooren1,2 1Department of Ophthalmology, Amphia Hospital, Breda, 2Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands Purpose: To describe the results of cataract extraction with toric intraocular lens (IOL implantation in patients with preexisting astigmatism from three corneal conditions (keratoconus, postkeratoplasty, and postpterygium surgery.Methods: Cataract patients with topographically stable, fairly regular (although sometimes very high corneal astigmatism underwent phacoemulsification with implantation of a toric IOL (Zeiss AT TORBI 709, Alcon Acrysof IQ toric SN6AT, AMO Tecnis ZCT. Postoperative astigmatism and refractive outcomes, as well as visual acuities, vector reduction, and complications were recorded for all eyes.Results: This study evaluated 17 eyes of 16 patients with a mean age of 60 years at the time of surgery. Mean follow-up in this study was 12 months. The corrected distance Snellen visual acuity (with spectacles or contact lenses 12 months postoperatively was 20/32 or better in 82% of eyes. The mean corneal astigmatism was 6.7 diopters (D preoperatively, and 1.5 D of refractive cylinder at 1-year follow-up. No vision-compromising intra- or postoperative complications occurred and decentration or off-axis alignment of toric IOLs were not observed.Conclusion: Phacoemulsification with toric IOL implantation was a safe and effective procedure in the three mentioned corneal conditions. Patient selection, counseling, and IOL placement with optimal astigmatism correction are crucial. Keywords: toric intraocular lens, phacoemulsification, corneal astigmatism, keratoconus, postkeratoplasty, postpterygium surgery

  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. 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

  5. An investigation of the effect of silicone oil on polymer intraocular lenses by means of PALS, FT-IR and Raman spectroscopies.

    Science.gov (United States)

    Chamerski, Kordian; Lesniak, Magdalena; Sitarz, Maciej; Stopa, Marcin; Filipecki, Jacek

    2016-10-01

    The effect of the polydimethylsiloxane (PDMS) based silicone oil, that is widely used in vitreoretinal surgery, on internal structures of the polymer intraocular lenses was investigated. The effect of PDMS was studied on the polymethyl methacrylate (PMMA) rigid lenses and poly(2-hydroxyethyl methacrylate) (PHEMA) flexible lenses. The research was carried out by means of the positron lifetime spectroscopy (PALS) as well as the infrared spectroscopy (FT-IR) and the Raman spectroscopy (RS). The studies involving the use of PALS and FT-IR methods have revealed that the PHEMA based lenses absorbed, whereas the PMMA lenses did not absorb, silicone oil. The results obtained with the use of the RS method were inconclusive, probably due to the too low intensity of the characteristic PDMS bands. The evidence from this study was discussed in terms of physics and related to the clinical use of both silicone oil and intraocular lenses. PMID:27261889

  6. An investigation of the effect of silicone oil on polymer intraocular lenses by means of PALS, FT-IR and Raman spectroscopies

    Science.gov (United States)

    Chamerski, Kordian; Lesniak, Magdalena; Sitarz, Maciej; Stopa, Marcin; Filipecki, Jacek

    2016-10-01

    The effect of the polydimethylsiloxane (PDMS) based silicone oil, that is widely used in vitreoretinal surgery, on internal structures of the polymer intraocular lenses was investigated. The effect of PDMS was studied on the polymethyl methacrylate (PMMA) rigid lenses and poly(2-hydroxyethyl methacrylate) (PHEMA) flexible lenses. The research was carried out by means of the positron lifetime spectroscopy (PALS) as well as the infrared spectroscopy (FT-IR) and the Raman spectroscopy (RS). The studies involving the use of PALS and FT-IR methods have revealed that the PHEMA based lenses absorbed, whereas the PMMA lenses did not absorb, silicone oil. The results obtained with the use of the RS method were inconclusive, probably due to the too low intensity of the characteristic PDMS bands. The evidence from this study was discussed in terms of physics and related to the clinical use of both silicone oil and intraocular lenses.

  7. Toric intraocular lenses for correction of astigmatism in keratoconus and after corneal surgery

    Science.gov (United States)

    Mol, Ilse EMA; Van Dooren, Bart TH

    2016-01-01

    Purpose To describe the results of cataract extraction with toric intraocular lens (IOL) implantation in patients with preexisting astigmatism from three corneal conditions (keratoconus, postkeratoplasty, and postpterygium surgery). Methods Cataract patients with topographically stable, fairly regular (although sometimes very high) corneal astigmatism underwent phacoemulsification with implantation of a toric IOL (Zeiss AT TORBI 709, Alcon Acrysof IQ toric SN6AT, AMO Tecnis ZCT). Postoperative astigmatism and refractive outcomes, as well as visual acuities, vector reduction, and complications were recorded for all eyes. Results This study evaluated 17 eyes of 16 patients with a mean age of 60 years at the time of surgery. Mean follow-up in this study was 12 months. The corrected distance Snellen visual acuity (with spectacles or contact lenses) 12 months postoperatively was 20/32 or better in 82% of eyes. The mean corneal astigmatism was 6.7 diopters (D) preoperatively, and 1.5 D of refractive cylinder at 1-year follow-up. No vision-compromising intra- or postoperative complications occurred and decentration or off-axis alignment of toric IOLs were not observed. Conclusion Phacoemulsification with toric IOL implantation was a safe and effective procedure in the three mentioned corneal conditions. Patient selection, counseling, and IOL placement with optimal astigmatism correction are crucial. PMID:27382249

  8. 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.

  9. Visian implantable contact lens versus AcrySof Cachet phakic intraocular lenses: comparison of aberrmetric profiles

    Directory of Open Access Journals (Sweden)

    Hosny MHM

    2013-07-01

    Full Text Available Mohamed HM Hosny, Ahmad MM ShalabyDepartment of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, EgyptPurpose: To evaluate the in vivo aberrometric performance of two phakic intraocular lenses (PIOLs; the Visian implantable contact lens (ICL and the AcrySof Cachet PIOL.Methods: Thirty eight eyes from 29 patients with an age range of 23–32 years and more than 9 D of myopia were divided into two groups; one group of 20 eyes received a Visian ICL model V4c, another group of 18 eyes received an AcrySof Cachet PIOL. Total higher order aberrations (HOAs root mean square, total coma, and total spherical aberrations were recorded pre and 6 weeks postoperatively to evaluate and compare the aberrometric performance of the Visian ICL and the AcrySof Cachet PIOL implanted in highly myopic patients.Results: Preoperatively, there were no significant differences in any studied parameters, except for preoperative spherical equivalent. Postoperatively, there were no statistically significant differences in the induction of HOAs between both PIOLs. The reduction in spherical aberrations was statistically significant in each group as well as in all study patients.Conclusion: Both AcrySof Cachet PIOL and ICLs are effective phakic implants to correct high refractive errors. They both induce small amounts of negative spherical aberration that do not affect the total HOAs, yet reduce the positive ocular spherical aberration. This result is expected to improve the quality of vision in such patients.Keywords: high myopia, higher order aberrations, refractive procedures, phakic implants

  10. Capsule Contraction Syndrome with a Microincision Foldable Hydrophilic Acrylic Intraocular Lens: Two Case Reports and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Angelo Balestrazzi

    2014-10-01

    Full Text Available Here we present 2 cases of capsule contraction syndrome (CCS. In both cases, a hydrophilic acrylic Akreos MI60 (Bausch and Lomb intraocular lens (IOL was implanted in the capsular bag through microincision cataract surgery, and the literature on the subject is reviewed. Since CCS has been described after the implantation of every IOL type, it is unlikely that the Akreos MI60 chemical and physical properties may cause CCS. When CCS occurs with IOLs composed of increasingly flexible materials that are inserted through incisions of decreasing size, a severe dislocation and deformation of IOL optics and haptics may develop. In both cases illustrated here, Nd:YAG laser anterior capsulotomy was highly effective. Hence, also based on the literature, which reports severe complications as a result of surgical intervention, it is suggested that Nd:YAG laser anterior capsulotomy be the first line of CCS treatment when the luxation of an IOL capsular bag is absent.

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lin Lin; Wang Yao; Huang Xiaodan [Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China); Xu Zhikang [Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Yao Ke, E-mail: xlren@zju.edu.cn [Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China)

    2010-10-01

    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.

  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. 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

  15. Incidence of posterior capsule opacification following the implantation of a foldable hydrophilic acrylic intraocular lens: a 4 year follow-up study

    OpenAIRE

    Priscilla de Almeida Jorge; Delano Jorge; Camila Vieira Ventura; Bruna Vieira Ventura; Wagner lira; Marcelo Carvalho Ventura; Marcony Rodrigues de Santhiago; Newton Kara-Junior

    2014-01-01

    Purpose: To evaluate the incidence of posterior capsule opacification (PCO) four years after the implantation of a hydrophilic acrylic intraocular lens (IOL). Methods: Fifty-eight randomly selected eyes from 58 patients were analyzed four years after phacoemulsification and Ioflex IOL implantation. The patients underwent an ophthalmic examination to detect PCO and a detailed medical history was obtained. The patients' charts were reviewed for their corrected distance visual acuity prior to ...

  16. 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

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

    International Nuclear Information System (INIS)

    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

  18. Comparison of ocular straylight after implantation of multifocal intraocular lenses

    NARCIS (Netherlands)

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

    2016-01-01

    UNLABELLED: A comprehensive review of the effect of multifocal intraocular lens (IOL) designs on postoperative ocular straylight was performed. Studies reporting straylight values obtained with the natural pupil using the C-Quant device after uneventful multifocal IOL implantation were included. The

  19. 不同人工晶体植入术后白内障患者的视力满意度调查%The survey of patients'satisfaction of sight after implanted different intraocular lenses

    Institute of Scientific and Technical Information of China (English)

    韦秋红; 陈琛; 杜卫静

    2013-01-01

    Objective:To investigate patients’postoperative visual satisfaction of phacoemulsification in order to provide reference for the choice of IOL. Method:347 patients after phacoemulsification were inquired satisfaction of vision. Results: There 286 patients finished the survey. There were 79 patients implanted clear intraocular lenses, 79 patients implanted yel ow intraocular lenses, 80 patients implanted photochromic intraocular lenses, 58 patients implanted aspheric intraocular lenses and 54 patients implanted multifocal intraocular lenses. Few implanted multifocal intraocular lenses patients had reading difficulty. But most implanted monofocal intraocular lens patients had reading difficulty. Implanted clear intraocular lenses patients and yel ow intraocular lenses patients had more difficulty at night and in distinguishing color than the patients implanted photochromic intraocular lenses. Conclusions:multifocal intraocular lenses and aspheric intraocular lenses indeed could improve the visual quality of postoperative patients.%目的:调查植入不同人工晶体材料的白内障患者术后视力满意度,更好的为白内障手术提供参考。方法:对2000年至2010年于我院行白内障手术的347例白内障患者进行回访和问卷调查。了解白内障术后患者的术后视觉满意度和生活质量。结果:286人完成问卷调查,植入普通折叠人工晶体者79例,蓝光滤过人工晶体者79例,光变色人工晶体者80例,非球面人工晶体者58例,多焦点人工晶体者54例。植入多焦点人工晶体的患者术后很少有阅读困难、夜间活动困难以及眩光现象。植入单焦点人工晶体的患者大多数表示有阅读困难。其中植入普通折叠人工晶体和蓝光滤过人工晶体的患者比植入光变色人工晶体的患者有更多的夜间活动障碍和视色困难。结论:多焦点及非球面人工晶体的确可以明显的改善患者术后的视觉质量。

  20. AN EXPERIMENTAL STUDY OF THE INTERLEUKIN 1 LEVELS IN AQUEOUS HUMOR AFTER TRANSSCLERAL FIXATION OF INTRAOCULAR LENSES

    Institute of Scientific and Technical Information of China (English)

    周朝晖; 何守志

    1998-01-01

    Purpose. To study the interleukin 1 (IL-1) levels in aqueous humor after transscleroal fixation of intraocular lenses (IOLs) implantation in rabbits and disciss the effect of IL-1 on postoperative anterior ocular inflammation, Methods. Twenty-seven pigmented rabbits were divided into three groups: G1, transscleral fixation of posterior chamber (PC) IOLs implantation; G2, Lens of rabbits were removed without IOLs implantation; GS, the control group, without surgical intervention. On the Ist, 3rd, 7th and 14th postoperative days, aqueous humor samples were obtained. Methyl thiazolyl tetrazolium(MTT) colormetry was used to detected for the presence of IL-1. The data were analyzed hy using analysis of variance of SAS soft ware. Results. It was found that IL-1 level in aqueous humor was increased after transscleral fixation of IOLs implantatlon, IL-1 level reached its maximum on the 14th postoperative days in the IOL implanted group. IL-1 levels on 1st, 3rd, 7th and 14th days postoperatively was significantly higher (P<0. 05) in IOLs implanted group than that of only extracapsular lenses extraction but no IOLs implantation group and that of the none sttrgical intervention group. Conclusions. IL-1 levels increased had a close relationship with a specific response to IOL implantation. The increase of IL-1 may be suggested as the principal mediators of immunological and inflammlatory responses, so that may play critical role in anterior ocular inflammative response after IOL implantation.

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

    OpenAIRE

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

    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 ...

  2. Comparison of retinal image quality with spherical and customized aspheric intraocular lenses

    OpenAIRE

    Guo, Huanqing; Goncharov, Alexander V.; Dainty, Chris

    2012-01-01

    We hypothesize that an intraocular lens (IOL) with higher-order aspheric surfaces customized for an individual eye provides improved retinal image quality, despite the misalignments that accompany cataract surgery. To test this hypothesis, ray-tracing eye models were used to investigate 10 designs of mono-focal single lens IOLs with rotationally symmetric spherical, aspheric, and customized surfaces. Retinal image quality of pseudo-phakic eyes using these IOLs together with individual variati...

  3. Toric intraocular lenses for correction of astigmatism in keratoconus and after corneal surgery

    OpenAIRE

    Mol, Ilse

    2016-01-01

    Ilse EMA Mol,1,2 Bart TH Van Dooren1,2 1Department of Ophthalmology, Amphia Hospital, Breda, 2Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands Purpose: To describe the results of cataract extraction with toric intraocular lens (IOL) implantation in patients with preexisting astigmatism from three corneal conditions (keratoconus, postkeratoplasty, and postpterygium surgery).Methods: Cataract patients with topographically stable, fairly regular (although sometim...

  4. Optical aberrations of intraocular lenses measured in vivo and in vitro

    Science.gov (United States)

    Barbero, Sergio; Marcos, Susana; Jiménez-Alfaro, Ignacio

    2003-10-01

    Corneal and ocular aberrations were measured in a group of eyes before and after cataract surgery with spherical intraocular lens (IOL) implantation by use of well-tested techniques developed in our laboratory. By subtraction of corneal from total aberration maps, we also estimated the optical quality of the intraocular lens in vivo. We found that aberrations in pseudophakic eyes are not significantly different from aberrations in eyes before cataract surgery or from previously reported aberrations in healthy eyes of the same age. However, aberrations in pseudophakic eyes are significantly higher than in young eyes. We found a slight increase of corneal aberrations after surgery. The aberrations of the IOL and the lack of balance of the corneal spherical aberrations by the spherical aberrations of the intraocular lens also degraded the optical quality in pseudophakic eyes. We also measured the aberrations of the IOL in vitro, using an eye cell model, and simulated the aberrations of the IOL on the basis of the IOL's physical parameters. We found a good agreement among in vivo, in vitro, and simulated measures of spherical aberration: Unlike the spherical aberration of the young crystalline lens, which tends to be negative, the spherical aberration of the IOL is positive and increases with lens power. Computer simulations and in vitro measurements show that tilts and decentrations might be contributors to the increased third-order aberrations in vivo in comparison with in vitro measurements.

  5. Intraocular lens employed for cataract surgery

    International Nuclear Information System (INIS)

    The aim of this paper is to illustrate the techniques of cataract surgery with implantation of intraocular lenses and some physical properties of the used materials. The new technology, coupled with extensive experience and the studied cases, permits to increase the standardization and accuracy of the engravings, by reducing the use and handling of surgical instruments inside the eye. At present it is possible to replace the cataract with crystalline lenses based on biopolymers such as PMMA, silicone, acrylic hydrophilic and hydrophobic acrylic. These materials are increasingly able to replace the natural lens and to ensure the fully functional of the eye. The role of femtosecond lasers in cataract surgery, to assist or replace several aspects of the manual cataract surgery, are discussed.

  6. Intraocular lens employed for cataract surgery

    Science.gov (United States)

    Roszkowska, A. M.; Torrisi, L.

    2014-04-01

    The aim of this paper is to illustrate the techniques of cataract surgery with implantation of intraocular lenses and some physical properties of the used materials. The new technology, coupled with extensive experience and the studied cases, permits to increase the standardization and accuracy of the engravings, by reducing the use and handling of surgical instruments inside the eye. At present it is possible to replace the cataract with crystalline lenses based on biopolymers such as PMMA, silicone, acrylic hydrophilic and hydrophobic acrylic. These materials are increasingly able to replace the natural lens and to ensure the fully functional of the eye. The role of femtosecond lasers in cataract surgery, to assist or replace several aspects of the manual cataract surgery, are discussed.

  7. A truly knotless technique for scleral fixation of intraocular lenses: Two-year results

    Directory of Open Access Journals (Sweden)

    Naresh K Yadav

    2012-01-01

    Full Text Available Scleral fixated intraocular lens (SFIOL is a safe and effective option for managing optical aphakia. Suture related complications like suture erosion, suture breakage, endophthalmitis, etc. are unique to SFIOL. The knots can be covered by partial thickness flaps or they can be rotated into scleral tissues without flaps to reduce the complications. We performed a recently described novel technique which obviates the need for knot and scleral flaps in securing the SFIOL. This novel 2-point Ab externo knotless technique may reduce the knot related problems. Twenty-three eyes undergoing this knotless SFIOL procedure were analyzed for intraoperative and postoperative complications. Twenty-two eyes either maintained or improved on their preoperative vision. All patients had a minimum follow-up of 24 months.

  8. Correction of high myopia with foldable Artiflex Phakic intraocular lenses: 1 year follow-up results.

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2013-09-01

    Full Text Available To assess the one year results of Artiflex Phakic intraocular lens (IOL implantation in the treatment of high myopia. In this non-random interventional study, myopic patients with spherical equivalent worse than -5.0 diopters (D who were not eligible for laser surgery were assessed. All patients had refraction, uncorrected and best corrected visual acuity tests (UCVA and BCVA, endothelial cell count (ECC, and measurement of the anterior chamber depth and intraocular pressure before surgery and at 1, 3, 6, and 12 months after surgery. Main outcome measures of this study were refractive stability, refractive predictability, safety, and efficacy after implanting Artiflex IOLs. We studied 53 eyes of 20 female and 8 male patients. The mean preoperative spherical equivalent was -10.22±3.02 D which reached -0.69±1.08 D one year after surgery (P<0.001. On the last follow-up visit, 75% of the eyes were within +0.5 D of emmetropia, 2 eyes had lost one line of BCVA, 18.75% had gained one line and 31.25% had gained 2 or more lines of BCVA. Others showed no change in BCVA. At one year after surgery, 72.2% of the eyes had 20/25 vision or better. The safety and efficacy indices were 1.16 and 1.05, respectively. ECC showed 3.04% decrease (P=0.176. In cases where laser surgery is not an option for myopic patients, use of Artiflex IOLs can have good results with acceptable safety and efficacy.

  9. Biological safety of hydrophobic acrylic foldable intraocular lens%疏水性丙烯酸酯折叠式人工晶体的生物安全性

    Institute of Scientific and Technical Information of China (English)

    段晓杰; 姜宝光; 王召旭

    2015-01-01

    背景:在临床试验前,需对疏水性丙烯酸酯人工晶体以新西兰白兔作为植入对象进行生物学评价。目的:观察新型疏水性丙烯酸酯折叠式人工晶体的生物安全性。方法:取新西兰家兔12只,右侧眼做实验眼,植入沈阳百奥医疗器械有限公司研制疏水性丙烯酸酯折叠式人工晶体,左侧眼做对照眼,植入美国爱尔康公司的Acrysof IQ SN60WF人工晶体。结果与结论:与对照眼相比,兔实验眼植入后各时间点角膜、前房、植入物位置、眼后节变化差异无显著性意义;且角膜和晶体囊袋无炎症反应,组织增生差异无显著性意义;人工晶体表面无巨噬细胞等炎症细胞,晶体表面、襻根部可见纤维组织。说明此款新材料与临床中已经广泛应用的产品无显著差别,即具有生物安全性。%BACKGROUND:Hydrophobic acrylic foldable intraocular lens should be evaluated biologicaly with New Zealand rabbits as implant objects prior to clinical trial. OBJECTIVE:To observe the biological safety of hydrophobic acrylic foldable intraocular lens. METHODS: Twelve New Zealand rabbits were enroled. The right eyes were implanted with self-developed hydrophobic acrylic foldable intraocular lens (Shenyang Baiao Medical Device Co., Ltd., China) as experimental group, and the left eyes were implanted with Acrysof IQ SN60WF (Alcon, USA) as control group. RESULTS AND CONCLUSION: After implantation, there were no significant differences in the cornea, anterior chamber, implant position, posterior segment of eyebal between two groups. Tissue proliferation had no obviously difference between the two groups, and there were cornea and lens pouch inflammations. No macrophages and other inflammatory cels were visualized on the surface of intraocular lens, and fibrous tissues were found on the intraocular lens surface and in the haptics root. These findings suggest that the self-developed hydrophobic acrylic

  10. A knotless, one-haptic fixation of posterior chamber intraocular lenses: one-year results

    Institute of Scientific and Technical Information of China (English)

    Pipat; Kongsap

    2015-01-01

    AIM: To assess the results of a modified technique for scleral fixation of a posterior chamber intraocular lens(IOL) in eyes which had deficient of posterior capsular support.METHODS: This retrospective study was comprised of ten patients with deficient posterior capsular support who underwent one-haptic fixation of posterior chamber IOLs, between February 2010 and October 2011. IOL as implanted with one haptic supported on the capsular remnant and the other haptic drawn into the sulcus by anchoring suture without a knot. All patients were evaluated for pre- and postoperative visual acuity, lens centration, intra-and postoperative complications.RESULTS: A knotless, one-haptic fixation of posterior chamber IOLs has successfully been performed on ten eyes. All cases had inadequate capsular support(i.e. a capsular tear ranged from 5 to 7 clock hours). The average age was 74.25 ±8.87y(SD). The average postoperative uncorrected visual acuity was 0.51 log MAR.Complications included hyphema in one eye, a mild inflammatory reaction in the anterior chamber in two eyes, and a transient rise in IOP in one eye. Neither IOL tilt nor dislocation was observed and there were no later complications.CONCLUSION: In the presence of insufficient capsular support, a knotless, one-haptic fixation of posterior chamber IOLs is a safe and viable option which reduces the operation time, and minimizes postoperative suture-related complications.

  11. 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. PMID:26294964

  12. 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.

  13. Out-of-the-bag intraocular lens dislocation: outcomes of posterior chamber intraocular lens exchange, risk factors, and prevention

    Institute of Scientific and Technical Information of China (English)

    ZHENG Dan-ying; CHEN Li-na; SUN Yi; SHAO Ying-feng; LIANG Jing-li; LIU Yi-zhi

    2010-01-01

    eye, 2.8%) and anterior vitreous cavity (6 eyes, 16.7%) was found in this series. The foldable intraocular lenses (acrylic or silicone) were explanted from 27 eyes (75%) and rigid intraocular lenses (poly methyl methacrylate,PMMA) from 9 eyes (25%). The most common explanted intraocular lens material was single-piece acrylic (13 pieces,36.1%), followed by 3-piece acrylic (9 pieces, 25%), single-piece PMMA (9 pieces, 25%), and 3-piece silicone (5 pieces,13.9%). Uncorrected visual acuity postoperatively improved in 29 eyes (81%), unchanged in 4 eyes (11%), and worsened in 3 eyes (8%) in comparison to that before exchange operation (P=0.006). Best corrected visual acuity tended to improve, but the improvement was not significant (P=0.206). Complications related to lens exchange surgery were mainly intraocular lens redislocation (1 eye), retinal detachment (1 eye), vitreous hemorrhage (1 eye), and cystoid macular edema (1 eye).Conclusions Out-of-the-bag intraocular lens dislocation was mainly caused by posterior capsule rupture during the initial cataract extraction procedure and the foldable lens was the most common dislocated intraocular lens. In most cases, posterior chamber intraocular lens exchange surgery could provide satisfied final visual outcomes.

  14. Tilt and decentration tolerance of intraocular lenses: measurements with an improved mechanical model eye

    Science.gov (United States)

    Traxler, Lukas; Reutterer, Bernd; Bayer, Natascha; Rank, Elisabet; Krause, Sylvio; Beckert, Erik; Drauschke, Andreas

    2016-03-01

    Cataract, a clouding of the crystalline eye lens, is the leading cause of blindness. It can effectively be treated by cataract surgery, where the clouded lens is replaced by an artificial intraocular lens (IOL). Postoperative healing processes can cause a displacement of the IOL, which further leads to the fact that the quality of vision is deteriorated. Studies have shown that the imaging quality of high sophisticated IOL designs is more sensitive to lens displacements than simpler designs. The effects of IOL displacements are not well represented and tested within the current IOL test standard ISO 11979-2. This fact leads to the necessity to develope new test standards for novel and more sophisticated IOL designs. In this paper we present an improved model eye, which extends the current standard in three main aspects: First, the eye-model is very close to the physiology of the human eye. Second, electromechanic drives allow an automatic and precise simulation of postoperative lens tilts and decentrations, and finally in addition to standard conform MTF analysis, in the proposed setup also wavefront aberrations are measured. The latter reveals specific image aberrations caused by lens displacements. The model eye allows to objectively analyze the displacement tolerance of various IOL designs. The functionality of this novel setup is tested by measuring a spherical and an aspheric IOL design. Additionally, for comparison, IOLs that were already investigated with a previous version of the presented model eye are used for analysis. Measurements results reveal improvements compared to the previous version of the model eye and a functional prototype for wavefront measurement.

  15. Membrane Formation on the Surface of implanted Posterior Chamber Intraocular Lenses

    Institute of Scientific and Technical Information of China (English)

    FangyaoYang; GuijunWu

    1995-01-01

    Purpose:To study the prevention and treatment of the membrane formation on the lens surface after extracapsular cataract extraction(ECCE)with posterior chamber intraocular lens(PCIOL)implantation.Methods:We reviewed the records of 312 cataractous patients that had undergone ECCEwith PCIOLimplantation between1989and1993,Postoperatively all pa-tients were examined under slit-lamp microscopy.The membrane formation on the surface of PCIOLin pupilar area was divided into four grades.Two mem-branes of surgical removal were observed under a transmission electrom mi-croscopy.One PCIOLof surgical removal was observed under a scanning electron microscopy.Results;Of312 patients,21 had the membrane formation on the surface of the PCIOL postoperatively.The incidence of the membrane formation was6.7%.Comparisone with cases of senile cataract showed the incidence to be significantly the highest among;1.patients who had traumatic cataract(P<0.05);2.pa-tients with complicated cataract(P<0.05).Interoperatively residual lens corten and rupture of posterior capsule,interval time betwwen the first and second eye operations less than 1month are the main factors of menbrane formation.The ultrastructure in membrane and cytology on the lens surface showed that the membrane on the surface of PCIOLs is usually composed of acellular protein film and cellular elements,including macrophages.fibroblast-like cells,epithelioid cells,giant cells,fibroblasts and collagen fibrils,etc.Conclusions:The cellular response on the surface of an implanted PCIOLis a chonic foreign-body inflammatory reaction and the membrane of the surfaceof implanted PCIOL is a reactive membrane of the foreign-body.Eye Science1995;11:131-135.

  16. Evaluation of actual retinal images produced by misaligned aspheric intraocular lenses in a model eye

    Directory of Open Access Journals (Sweden)

    Fujikado T

    2014-11-01

    Full Text Available Takashi Fujikado,1 Makoto Saika2 1Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan; 2Research and Development Department of Topcon Corporation, Tokyo, Japan Purpose: To examine the effect of misalignment (decentration and tilt of intraocular lenses (IOLs on retinal image quality using a water-immersed model eye with corneal spherical aberration adjusted to the values found in normal human eyes (spherical aberration 0.25 µm; pupil diameter 6 mm.Methods: Three types of IOL holders were prepared. The first was without decentration or tilt, the second had a decentration of 0.5 mm, and the third had a tilt of 5.0°. One spherical IOL and three aspherical IOLs, each with a power of +20 D, were set in the holders and their optical properties (wave front aberration, defocused modulation transfer function, defocused point spread function, and Landolt ring simulations were compared.Results: Coma aberrations generated by misaligned IOLs were related to the spherical aberration corrective power of the IOLs. Landolt ring simulations show that the depth of focus increased as spherical aberration increased and that the retinal image quality was degraded by increases in coma aberration.Conclusion: Coma aberration was generated by IOLs with a large degree of spherical aberration correction, leading to reduced retinal image quality when the IOL was misaligned. This suggests that, in a clinical setting, the quality of vision might be improved by reducing the degree of coma aberration using IOLs that retain, or minimally correct, spherical aberration. Keywords: coma aberration, decentration, misalignment, spherical aberration, tilt

  17. Comparison of posterior capsule opacification at 360-degree square edge hydrophilic and sharp edge hydrophobic acrylic intraocular lens in diabetic patients

    Institute of Scientific and Technical Information of China (English)

    Ling; Bai; Jin; Zhang; Ling; Chen; Ting; Ma; Hou-Cheng; Liang

    2015-01-01

    ·AIM: To compare posterior capsule opacification(PCO)degree and visual functions after phacoemulsification in eyes implanted with 360-degree square edge hydrophilic acrylic intraocular lens(IOL)(570C C-flex, Rayner) and sharp edge hydrophobic acrylic IOL(Sensar AR40 e,AMO) in diabetic patients.· METHODS: Sixty diabetic patients underwent uneventful phacoemulsification and randomly implanted one of the two IOLs. The PCO value was measured by retroillumination photographs and Evaluation of Posterior Capsule Opacification(EPCO) 2000 image-analysis software at 1, 6, 12, and 24 mo after surgery. Visual acuity, and contrast sensitivity in photopic and mesopic conditions were also examined at each follow up time point. The incidence of eye that required Nd:YAG laser posterior capsulotomy were also compared.·RESULTS: There was not any statistically significant difference in PCO scores between Rayner C-flex 570 C group and Sensar AR40 e group at each follow up time point. Visual acuity, Nd:YAG capsulotomy incidence and contrast sensitivity also had no significant difference during the 24 mo follow-up.·CONCLUSION: For diabetic patients, Rayner 570 C Cflex and Sensar AR40 e IOLs are same effective for prevent PCO. The 360-degree square edge design maybe is a good alternative technique to improve PCO prevention.

  18. 亲水性丙烯酸酯人工晶状体植入后的生物相容性和并发症%Hydrophilic acrylic intraocular lens:biocompatibility and complications following implantation

    Institute of Scientific and Technical Information of China (English)

    魏芬; 艾明

    2015-01-01

    BACKGROUND:Hydrophilic acrylic materials with good biocompatibility have been widely used in clinic. However, there are some problems about the biocompatibility and safety of hydrophilic acrylic intraocular lens after long-term clinical application. OBJECTIVE:To discuss the biocompatibility and stability issues and corresponding processing methods after hydrophilic acrylic intraocular lens implantation. METHODS:A computer-based search of Wanfang and PubMed database was performed for articles related to clinical application of hydrophilic acrylic intraocular lens published from 2005 to 2014. The keywords were “hydrophilic acrylic,intraocular lens” in Chinese and English, respectively. A total of 618 articles were initialy retrieved, and finaly 35 articles were included in result analysis. RESULTS AND CONCLUSION:As the hydrophilic acrylic intraocular lens is foldable, a smal incision is required for implantation and the operation is simple that cause less damage to the patients. In addition, the hydrophilic acrylic intraocular lens has poor bacterial and inflammatory cel adhesion, which leads to a low probability of infective endophthalmitis after implantation. But there is a high incidence of posterior capsule opacification as wel as some refractive errors and visual quality problems after implantation. Taken together, to solve these problems depends on the continuous improvements and updates of intraocular lens materials and designs.%背景:亲水性丙烯酸酯材料的生物相容性良好,在临床得到广泛的应用。但随着亲水性丙烯酸酯人工晶状体临床应用的时间延长,其长期的生物相容性及稳定性问题逐渐显现。目的:讨论亲水性丙烯酸酯人工晶状体植入后的生物相容性及稳定性问题和处理方法。方法:应用计算机检索万方数据库及PubMed数据库2005至2014年与亲水性丙烯酸酯人工晶状体临床应用相关的文献,中文检索词为“亲水性丙烯酸酯

  19. 大焦深人工晶体的设计%Design of multi-focus intraocular lenses

    Institute of Scientific and Technical Information of China (English)

    饶丰

    2012-01-01

    运用Zemax光学设计软件构建Liou-Brennan眼模型,设计了增大焦深的非球面、折射型多焦点和衍射型多焦点人工晶体,并用点列图和视锐度分析了所设计的人工晶体的光学质量。对于非球面人工晶体,在3mm瞳孔下,当人眼无球差时,最佳视锐度相当高,但焦深仅为1.4m^-1;当人眼球差为0.4λ时,最佳视锐度可达0.9,焦深达2.2m,同时在整个焦深范围内视觉质量均优越。对于衍射型和折射型多焦点人工晶体,在明视条件下,虽然视远和视近时视觉质量良好,但是中间距离的视锐度〈0.5。衍射型多焦点人工晶体只有81%的光能用于成像,远近焦点能量均分,且与瞳孔大小无关;折射型多焦点人工晶体的远近焦点能量与瞳孔大小相关。设计的人工晶体均能增大人眼的焦深,但各有优缺点,临床上应该酌情选用。%Abstract : The Liou-Brennan eye model is constructed using the optical design software ZEMAX. The Depth of Focus(DOF), extended Intraocular Lenses(IOL) that includes aspherical IOL, refractive muhifocal IOL and diffractive muhifocus IOL are included in the design. The optical performance of the pseudophakic eye for the designed IOLs is analyzed for both the spot diagram and visual acuity. For the pseudophakic eye with a 3 mm pupil, when the spherical aberration is fully corrected by the aspherical IOL, the best visual acuity reaches 1.2 with a DOF of only 1.4 m^1. When the spherical aberration is 0.4λ, the best visual acuity is 0.9 with a DOF as high as 2.2 m-^1. With the implantation of refractive or diffractive muhifocus IOLs, the pseudophakic eye has fairly good distant and near vision, while the intermediate vision is lower than 0. 5. Diffractive muhifocal IOL allows 81% input energy to image and the energy distribution is not affected by the pupil size. The energy distribution of the refractive multifocal IOL is dependent on the pupil

  20. Incidence of posterior capsule opacification following the implantation of a foldable hydrophilic acrylic intraocular lens: a 4 year follow-up study

    Directory of Open Access Journals (Sweden)

    Priscilla de Almeida Jorge

    2014-08-01

    Full Text Available Purpose: To evaluate the incidence of posterior capsule opacification (PCO four years after the implantation of a hydrophilic acrylic intraocular lens (IOL. Methods: Fifty-eight randomly selected eyes from 58 patients were analyzed four years after phacoemulsification and Ioflex IOL implantation. The patients underwent an ophthalmic examination to detect PCO and a detailed medical history was obtained. The patients' charts were reviewed for their corrected distance visual acuity prior to the IOL implantation, as well as for one month postoperatively. The Student's t-test was used for statistical analysis. Results: The mean age of patients without PCO was 74.6 ± 9.5 years, compared to 70.3 ± 15 years in patients with PCO. Four years after surgery, 39 of the 58 eyes (67% had detectable PCO and 24 eyes (41.3% had decreased visual acuity (VA due to PCO. These patients were referred for Nd:YAG laser capsulotomy. Three patients (5.1% had decreased VA due to glaucoma, IOL opacification, or age-related macular degeneration. Twelve eyes (20.7% presented mild PCO with unchanged VA. Systemic arterial hypertension was reported by 45% of the patients, and in 3.5% of these cases this was associated with diabetes mellitus. Conclusion: This study found the incidence of PCO to be 67% four years after phacoemulsification and Ioflex IOL implantation.

  1. claw intraocular lens

    OpenAIRE

    Gonnermann, Johannes

    2015-01-01

    There is a wide range of alternative fixation techniques of intraocular lenses in the absence of adequate capsular support, such as angle- or iris-supported anterior chamber lenses and intra- / transsclerally-fixated (suture, fibrin glue, etc.) and iris-supported posterior chamber lenses. All procedures have different advantages and disadvantages depending on the anatomical situation and integrity of the capsular bag complex and the neighboring structures such as the iris, sclera and corneal ...

  2. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

    Science.gov (United States)

    Gundersen, Kjell Gunnar; Potvin, Rick

    2016-01-01

    Purpose To compare the visual acuity (VA) and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL) and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye. Patients and methods Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated. Results Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (Pdashboard or grocery shelf. VA was similar between groups at viewing distances from 60 to 40 cm, corresponding to computer or reading distance. PMID:27274184

  3. Comparison of Visual Quality after Implantation of Big Bag and Akreos Adapt Intraocular Lenses in Patients with High Myopia

    Institute of Scientific and Technical Information of China (English)

    Shengsheng Ma; Dongjian Zheng; Ling Lin; Fanjian Meng; Yonggang Yuan

    2015-01-01

    Purpose: To compare vision quality following phacoemulsifi-cation cataract extraction and implantation of a Big Bag or Akreos Adapt intraocular lens (IOL) in patients diagnosed with high myopia complicated with cataract. Methods:.This was a randomized prospective control study. The patients with high myopia complicated with cataract , with axial length ≥28 mm,.and corneal astigmatism ≤1D were enrolled and randomly divided into the Big Bag and Akreos Adapt IOL groups. All patients underwent phacoemulsification cataract extraction and lens implantation..At 3 months after surgery,.intraocular high-order aberration was measured by a Tracey-iTrace wavefront aberrometer at a pupil diameter of 5 mm in an absolutely dark room and statistically compared be-tween two groups. The images of the anterior segment of eyes were photographed with a Scheimpflug camera using Penta-cam three-dimensional anterior segment analyzer..The tilt and decentration of the IOL were calculated by Image-pro plus 6.0 imaging analysis software and statistically compared between two groups. Results:.In total,.127 patients (127 eyes),..including 52 males and 75 females, were enrolled in this study. The total high-or-der aberration and coma in the Akreos Adapt group (59 eyes) were significantly higher compared with those in the Big Bag (P0.05). The horizontal and vertical decentration were significantly smaller in the Big Bag lens group than in the Akreos Adapt group (both P0.05). Conclusion:.Both Big Bag and Akreos Adapt IOLs possess relatively good intraocular stability implanted in patients with high myopia. Compared with the Akreos Adapt IOL, the Big Bag IOL presents with smaller intraocular high-order aberra-tion. Coma is the major difference between the two groups.

  4. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

    Science.gov (United States)

    Gundersen, Kjell Gunnar; Potvin, Rick

    2016-01-01

    Purpose To compare the visual acuity (VA) and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL) and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye. Patients and methods Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated. Results Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05) at vergences from −0.5 to −1.5 D (from 2 m to 67 cm viewing distance, P<0.05). There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05). Conclusion Both lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at viewing distances from 60 to 40 cm, corresponding to computer or reading distance. PMID:27274184

  5. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gundersen KG

    2016-05-01

    Full Text Available Kjell G Gundersen,1 Rick Potvin21IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USAPurpose: To compare the visual acuity (VA and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye.Patients and methods: Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated.Results: Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05 at vergences from -0.5 to -1.5 D (from 2 m to 67 cm viewing distance, P<0.05. There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05.Conclusion: Both lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at

  6. Synthesis and properties of acrylic copolymers for ocular implants

    Science.gov (United States)

    Reboul, Adam C.

    There is a need for flexible polymers with higher refractive index and extended UV absorbing properties for improved intraocular lenses (IOLs). This research was devoted to the synthesis of new acrylic copolymers for foldable IOLs and to studies concerning IOL polymer properties. New polymers were synthesized from phenylated acrylates copolymerized with N-vinyl carbazole derivatives using bulk free radical addition methods. The copolymers had low Tg values, high refractive index, and were flexible. The N-vinyl carbazole derivatives were characterized by NMR and copolymers were characterized by DSC, UV-Vis, and refractometry. New phenothiazine based UV absorbers with high extinction coefficients were also synthesized for incorporation into ocular materials. Patent disclosures on UV absorbers and high refractive index polymers were prepared. A so called "glistening" phenomenon that occurs in all foldable intraocular lenses currently in clinical use is poorly understood and was studied. Research on this microvoid forming behavior included studies and development of methods to inhibit glistening in low Tg acrylic based copolymers. Glistenings were characterized using SEM and optical microscopy. A novel technique for inhibiting glistening was found and a patent disclosure was prepared.

  7. Progress of Toric intraocular lenses%散光人工晶状体的应用进展

    Institute of Scientific and Technical Information of China (English)

    张劲松

    2010-01-01

    Astigmatism can affect visual quality and visual acuity, and it can be corrected by different methods. Toric intraocular lens (Toric IOL) which combined astigmatism correction and spherical correction together is a newest kind of functional intraocular lens. Using Toric IOL is a reliable, predictable and stable refractive correction choice. With Toric IOL popularized, more and more technical experience were accumulated. The patients selection, insert techniques and complications prevention were improved greatly.%散光会造成视觉质量和视力的下降,可以通过多种方法矫正.散光人工晶状体(Toric IOL)是将散光矫正与人工晶状体的球镜度数相结合的一种新型功能性人工晶状体.利用这种人工晶状体矫正角膜散光是一种合理的、预测性强、术后效果更加稳定的屈光矫正方式.随着Toric IOL在临床应用的推广,这一技术的应用经验得到不断的积累,Toric IOL的适应证选择、植入技术、并发症的预防等方面日趋完善.

  8. COMPARISON OF ANTERIOR CHAMBER REACTION WITH SINGLE-PIECE AND THREE-PIECE INTRAOCULAR LENSES IN MANUAL SMALL INCISION CATARACT SURGERY

    Directory of Open Access Journals (Sweden)

    Usha

    2014-11-01

    Full Text Available OBJECTIVES: To study the anterior chamber reaction between single-piece and three-piece intraocular lenses in manual small incision cataract surgery. METHODS: Prospective study done at Mysore Race Club Charitable Eye Hospital. 140 Patients underwent suture less sclerocorneal tunnel cataract surgeries with single-piece or three-piece Polymethylmethacrylate (PMMA intra ocular lenses (3-piece IOL. Accurate Keratometry was done with the help of Bausch and Lomb Keratometer. IOL power was calculated by using SRK (Sanders-Retzlaff-Kraff II formula, with the help of non-immersion, contact type of A-Scan biometry. Single-piece IOLs were inserted in 70 patients. Three-piece IOL inserted in rest of 70 patients. Slit lamp examination for anterior chamber cells was graded according to Hogan system. Aqueous cells were measured by counting within the visible field under Slit lamp, keeping the beam at maximum intensity. Anterior chamber reaction (AC in 1stPostoperative week and at 8 weeks are compared and analyzed by ANOVA statistics. RESULTS: Single piece IOL group had anterior chamber reaction ranging from 1 to 2+ cells i.e., in 97%. In three-piece IOL group, 70%of eyes had 2+ cells and 12.8% had 3± cells. At 8 weeks, single- piece IOL showed either no cells or occasional cells in 98.6% of patients, compared to three –piece IOL group showing in 77%of cases. 23% had 1+ cells in later group. CONCLUSION: Single-piece implanted IOLs had significant less number of cells were seen in anterior chamber from 1 week to 8 weeks as compared to three-piece IOLs.

  9. To guard against mistakes in selection of intraocular lenses%警惕人工晶状体选择的误区

    Institute of Scientific and Technical Information of China (English)

    何守志

    2008-01-01

    各种新型人工晶状体面世,为满足临床不同需求提供了更多的选择机会,对于推动白内障手术更趋完美起到了积极作用.但在进行人工晶状体选择时,尚存在很多误区.比如"贵的就是好的","新的就一定是完美的"等;还有重使用轻总结,片面夸大某些特殊功能等倾向.在人工晶状体选择时,如何充分考虑患者的需求,处理好特殊需求和基本需求之间的关系,避免盲目性,把最大的受益提供给患者,是我们共同面临的问题.%Development of different kinds of new intraocular lenses(IOL)provide more selections to meet various clinical requirements,which may plays an active role in making cataract surgery more perfectible.But there are many misunderstandings about how to select the proper IOL.For example,"the expensive one is the best one","new product is absolutely perfect",and SO on.Some surgeons prefer more practice and ignore the summary of the experiences.Someone unilaterally exaggerates some special function of IOL When selecting the IOL,it is a common challenge for us to fully consider the patients needs,and properly manage the relationship between the basic need and special need,and to avoid fanaticism,and provide the best benefits to the patients.

  10. Optical bench performance of AcrySof® IQ ReSTOR®, AT LISA® tri, and FineVision® intraocular lenses

    Directory of Open Access Journals (Sweden)

    Carson D

    2014-10-01

    Full Text Available Daniel Carson,1 Warren E Hill,2 Xin Hong,1 Mutlu Karakelle1 1Alcon Research, Ltd., Fort Worth, TX, USA; 2East Valley Ophthalmology, Mesa, AZ, USA Purpose: To compare the resolution and optical quality of the ReSTOR® +3.0 D and ReSTOR +2.5 D multifocal intraocular lenses (IOLs with the AT LISA® tri and FineVision® trifocal IOLs.Methods: Resolution, image quality, and photic phenomena were evaluated in the AcrySof® IQ ReSTOR +3.0 D and +2.5 D multifocal IOLs and compared with the AT LISA tri 839MP and FineVision Micro F12 trifocal IOLs, using a Badal optometer and a Snellen visual acuity chart. Simulated headlight images were obtained using a modulation transfer function (MTF bench and a 50 µm pinhole target. MTF values, using vertical and horizontal slits, were determined at far, intermediate, and near distances. Results: Resolution at 20/40 Snellen visual acuity equivalence was attainable over nearly the entire viewing distance range with the AT LISA tri and FineVision IOLs, but background shadows were more prominent with the AT LISA tri and FineVision IOLs than with the ReSTOR IOLs. Distance MTF peaks at 20/20 Snellen–equivalent spatial frequency were greatest for ReSTOR +2.5 D and ReSTOR +3.0 D IOLs. The near MTF peak occurred at 53 cm with ReSTOR +2.5 D and had a 20/20 Snellen–equivalent value that was lower than the near peaks of the other models but higher than the intermediate foci of the trifocal IOLs. Conclusion: AT LISA tri and FineVision trifocal IOLs achieved a useful third focus for intermediate vision but were associated with increased background halos and reduced distance visual quality compared with ReSTOR +2.5 D and +3.0 D multifocal IOLs. Keywords: multifocal, trifocal, modulation transfer function, Badal image, visual acuity, resolution

  11. Opaque intraocular lens implantation

    OpenAIRE

    Yusuf IH; Patel CK

    2013-01-01

    Imran H Yusuf, CK Patel The Oxford Eye Hospital, West Wing, John Radcliffe Hospital, Headley Way, Headington, Oxford, United KingdomWe read with great interest the recent article by Lee et al,1 who described their clinical experience with three patients who underwent primary implantation of Morcher (Stuttgart, Germany) occlusive intraocular lenses (IOLs) across a variety of neuro-ophthalmic indications. We hope to offer some further insight into these clinical observations in the context of o...

  12. Progresses of Materials of Intraocular Lenses and their Surface Modification%用于治疗白内障的人工晶体材料及表面修饰研究进展

    Institute of Scientific and Technical Information of China (English)

    牛国光; 朱思全; 郑欲东; 张红斌; 宋黎; 杨槐

    2008-01-01

      The recent development of surface modification and materials of intraocular lenses had been described at detail. The Bio-compatibility of materials surface-modified has been improved and post-operation syndrome reduced after modification. With the advancement of IOL materials, the size of incision would be smaller and IOL would prone to the property of bio-self accommodation.%  从材料角度对人工晶体材料及其表面修饰以及材料的发展做了详细介绍。通过表面改性提高了材料的生物相容性,降低术后并发症。人工晶体材料的发展,使得 IOL 植入手术切口更小,倾向于生理调节。

  13. Spectacle Independence after Cataract Extraction in Post-Radial Keratotomy Patients Using Hybrid Monovision with ReSTOR® Multifocal and TECNIS® Monofocal Intraocular Lenses

    OpenAIRE

    Gupta, Isha; Oakey, Zack; Ahmed, Faisal; Ambati, Balamurali K

    2014-01-01

    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 Implant...

  14. 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

  15. 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

  16. 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.

  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. Coated with nanomaterials intraocular lenses, ophthalmic and human body implantable devices with high catalytic antioxidant activities: a new nanotechnology strategy of peroxidase cellular enzyme mimics increasing the biocompatibility and therapeutic deployment of the medical prosthetic device.

    Science.gov (United States)

    Babizhayev, Mark A

    2013-04-01

    While cataract surgery is generally recognized as being one of the safest operations, there is still a significant complication rate. From 30 to 50% of all patients in the United States having cataract extraction develop opacification of the posterior lens capsule within two years and require laser treatment with its own significant risk of complications. Of the patients having cataract surgery, 0.8% develop retinal detachments, from 0.6% to 1.3% were rehospitalized for corneal edema or required corneal transplantation and about 0.1% presented with endophthalmitis . Thus, aside from secondary cataract, about 2% of 1.3 million people, or 26,000 individuals in the United States annually develop serious complications as a result of cataract surgery. The aim of this investigation was to increase the safety and effectiveness of an individual intraocular lens (IOL) preventing an impairment in peroxide metabolism of the mature human cataractous lenses compared to normal lenses employing the specific nanotechnology coating which substitutes the inhibitory effect of the implantable device towards the active species of oxygen and the ability of IOL to regulate the H2O2 and lipid hydroperoxides levels in the surrounding medium. The implantation of IOLs with metabolic activity improves the capability of the surrounding ocular tissues to withstand oxidative stress induced in ocular humors by the photochemical and other metabolic reactions. The coated implantable medical device with thin film of platinum applied with magnetron sputtering, reacts as a body enzyme with deleterious peroxide compounds and free radical oxygen species in body fluids and tissue when said device is implanted into human body. The IOL having haptics coated with thin film of platinum, catalyzes the reduction of peroxide compounds to decrease their levels within the aqueous humor. Further, the coatings also scavenge toxic free radicals of oxygen, thus preventing cellular dysfunction resulting from oxidative

  19. Estudo comparativo do desempenho visual e análise de frente de onda entre as lentes intra-oculares multifocais difrativas Tecnis® ZM900 e AcrySof® ResTor® SN60D3 Comparison between OPD-Scan results and visual outcomes of Tecnis® ZM900 and Restor® SN60D3 diffractive multifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Wilson Takashi Hida

    2008-12-01

    Full Text Available OBJETIVOS: Comparar o desempenho visual e a análise de frente de onda entre as lentes intra-oculares (LIOs multifocal difrativa Tecnis® ZM900 asférica e AcrySof® Restor® esférica SN60D3. MÉTODOS: Trata-se de estudo prospectivo comparativo que incluiu 78 olhos de 39 pacientes. A avaliação oftalmológica contou com medida da acuidade visual para longe, intermediária e curta distância, sem correção e com a melhor correção óptica, teste de sensibilidade ao contraste e análise de frente de onda por meio do aberrômetro OPD-Scan. RESULTADOS: Acuidade visual para longe e para perto sem correção óptica e análise de aberrometria foram estatisticamente semelhantes em relação a ambas as LIOs; já a visão intermediária e a sensibilidade ao contraste em condições fotópicas revelaram diferença estatisticamente significante entre as duas lentes a favor da Tecnis ZM900. CONCLUSÃO: Ambas as lentes intra-oculares promoveram excelente visão para longe e para perto em situações de alto contraste. A LIO Tecnis multifocal necessita de menos luminosidade para visão em situações de alto contraste, apresenta menos aberrações ópticas e melhor visão intermediária que a LIO ResTor.PURPOSE: Comparison of the visual performance and wavefront analysis between patients with Tecnis® ZM900 aspheric and AcrySof ReStor® SN60D3 spheric diffractive multifocal intraocular lenses (IOL. METHODS: This prospective comparative study included 78 eyes of 39 patients. The performed ophthalmologic evaluation included near, intermediate and distance corrected and uncorrected visual acuity, contrast sensitivity measurement (under photopic and mesopic conditions and wavefront analysis with the OPD-Scan aberrometrer. RESULTS: Uncorrected near and distance visual acuity and aberrometry analysis were similar with both intraocular lenses; nevertheless, intermediate visual acuity and contrast sensitivity under photopic conditions were statistically better

  20. Classification of intraocular lens and its intraocular biocompatibility%人工晶体分类及其在眼内的生物相容性

    Institute of Scientific and Technical Information of China (English)

    胡莉群

    2009-01-01

    目的:通过手术摘除自身浑浊晶体,植入人工晶体是治疗白内障的惟一有效措施.文章总结人工晶体材料的研究进展,为今后的临床应用和研究提供参考.方法:应用计算机检索1997/2009 Medline数据库、中国期刊网和万方数据库、SpringerLink数据库和ScienceDirect数据库.结果:共有25篇文章符合纳入标准.文章主要从人工晶体的发展现状、分类、生物相容性、人工晶体的并发症和发展趋势进行阐述.人工晶体按照硬度,可以分为硬质人工晶体和软性人工晶体.丙烯酸人工晶体比硅凝胶人工晶体的生物相容性更好.人工晶状体脱位是白内障摘除联合人工晶状体植入术后较常见的并发症之一.注入式人工晶体材料是今后研究的方向.结论:人工晶体植入眼内作为一种异物,机体对此产生反应是机体正常的防御现象.人工晶体材料和设计应充分的考虑人工晶体的生物相容性、术后视功能、调节功能、光保护等方面性能.保证术后的疗效和减少并发症的发生,使白内障患者获得更高质量的视力康复.%OBJECTIVE: The sole effective measure for cataract is replaced the epinephelos lens with intraocular lens. So, in this paper, we summarize the research process of intraocular lens, which can provide a reference for further study. METHODS: Medline, China Journal Net, Wanfang Data, SpringerLink, and ScienceDirect database were computer retrieved from 1997 to 2009. RESULTS: A total of 25 papers were included. All the papers were explained intraocular lens from the aspect of current situation, complication following implantation, and develop tendency. According to hardness, intraocular lens can be divided into hard intraocular lens and soft intraocular lens. Acrylic intraocular lenses showed better biocompatibility than the silicone intraocular lenses. In addition, the common complication following implantation was dislocation of lens. Therefore

  1. The measurement of intraocular pressure by non-contact tonometer through bandage contact lenses%应用非接触性眼压计经绷带型角膜接触镜的眼压测量

    Institute of Scientific and Technical Information of China (English)

    陈约洁; 王爱孙; 郑钦象

    2015-01-01

    Objective To evaluate the feasibility and accuracy of the measurement of inttrocular pressure (IOP) by non-contact tonometer (NCT) through bandage contact lenses.Methods IOPs were measured by (NCT) in 42 eyes of 42 patients with and without bandage contact lenses for three times each to get the averages.The values of with and without bandage contact lenses were compared.The correlation of the measurements with and without bandage contact lenses was analyzed.Results The measurement with bandage contact lenses appeared greater than the one without bandage contact lenses (15.26±6.81mmHg vs 13.05±6.16mmHg, P <0.05).The difference of IOPs was 2.21±2.04mmHg, with a maximum of 8mmHg, a minimum of-1.5mmHg, and 95% confidence interval (1.58-2.85mmHg).The measurements with bandage contact lenses significantly correlated with the measurements without bandage contact lenses (r =0.96, P <0.01), while the differences of IOPs did not significantly correlated with the native measurement (r =0.17, P =0.28).Conclusions The measurement of intraocular pressure by non-contact tonometer through bandage contact lens is feasible, so it's unnecessary to remove lenses frequently before the procedures, lest the corneas will be injured once more.However, it should be noted that IOPs through bandage contact lenses may be overestimated.%目的 评价非接触性眼压计(non-contact tonometry,NCT)经绷带型角膜接触镜测量眼压的可行性和准确性.方法 选取2013年11月至2014年6月在温州医科大学眼视光医院需要配戴绷带型角膜接触镜的角膜病、角膜外伤及角膜术后患者42例,共42只患眼.应用NCT分别在患者配戴角膜接触镜前、后测量眼压3次取平均值,比较配戴角膜接触镜前后眼压测值,并进行相关分析以判断角膜接触镜对眼压测量的影响.结果 42例患者配戴前的眼压为(13.05±6.16) mmHg,配戴后的眼压为(15.26±6.81) mmHg,差异有统计学意义(P<0.05),

  2. Visual and optical performance of diffractive multifocal intraocular lenses with different haptic designs: 6 month follow-up

    Directory of Open Access Journals (Sweden)

    Wang M

    2014-05-01

    Full Text Available Mengmeng Wang,1,* Christine Carole C Corpuz,1 Megumi Fujiwara,1 Minoru Tomita1,2,*1Shinagawa LASIK Center, Tokyo, Japan; 2Department of Ophthalmology, Wenzhou Medical College, Wenzhou, People’s Republic of China*These authors contributed equally to this workPurpose: To evaluate and compare the visual acuity outcomes and optical performances of eyes implanted with two diffractive multifocal intraocular lens (IOL models with either a plate haptic design or a modified-C design.Methods: This retrospective study comprised cataract patients who were implanted with either a plate haptic multifocal IOL model (AcrivaUD Reviol BB MFM 611 [VSY Biotechnology, Amsterdam, the Netherlands], group 1 or a modified-C haptic multifocal IOL model ( AcrivaUD Reviol BB MF 613 [VSY Biotechnology, Amsterdam, the Netherlands], group 2 between June 2012 and May 2013. The 6 month postoperative visual acuity, refraction, defocus curve, contrast sensitivity, and wave-front aberration were evaluated and compared between these eyes, using different IOL models.Results: One hundred fifty-eight eyes of 107 patients were included in this study. Significant improvement in visual acuities and refraction was found in both groups after cataract surgery (P<0.01. The visual acuity and contrast sensitivity were statistically better in group 1 than in group 2 (P<0.01. No statistically significant difference in the corneal higher-order aberrations was found between the two groups (P>0.05. However, the ocular higher-order aberrations in group 2 were significantly greater than in group 1 (P<0.05.Conclusion: At 6 months postoperatively, both AcrivaUD Reviol BB MFM 611 IOL and AcrivaUD Reviol BB MF 613 IOL achieved excellent visual and refractive outcomes. The multifocal IOL model with plate haptic design resulted in better optical performances than that with the modified-C haptic design.Keywords: AcrivaUD, VSY, plate haptic, modified-C haptic, multifocal

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

    Science.gov (United States)

    Kelkar, Aditya; Shah, Rachana; Kelkar, Jai; Kelkar, Shreekant; Arora, Ekta

    2015-01-01

    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. The Predictability of Preoperative Pilocarpine-Induced Lens Shift on the Outcomes of Accommodating Intraocular Lenses Implanted in Senile Cataract Patients

    Science.gov (United States)

    Li, Jin; Chen, Qi; Lin, Zhibo; Leng, Lin; Huang, Fang

    2016-01-01

    Purpose. To evaluate the predictability of lens shift induced by pilocarpine (LSPilo) on the outcomes of accommodating intraocular lens (Acc-IOL) implantation. Methods. Twenty-four eyes of 24 senile cataract patients who underwent phacoemulsification and Acc-IOL implantation were enrolled. LSPilo was evaluated with anterior segment optical coherence tomography (AS-OCT). At 3 months postoperatively, the best corrected distance visual acuities (BCDVA), distance-corrected near visual acuities (DCNVA), and subjective and objective accommodations were measured. IOL shifts under accommodation stimulus (IOLSAcc) were evaluated with AS-OCT. Results. The mean LSPilo was 112.29 ± 30.72 µm. LSPilo was not associated with any preoperative parameters. The mean IOLSAcc was 130.46 ± 42.71 µm. The mean subjective and objective accommodation were 1.54 ± 0.39 D and 1.27 ± 0.41 D, respectively. The mean postoperative BCDVA and DCNVA (log MAR value) were 0.22 ± 0.11 and 0.24 ± 0.12, respectively. LSPilo positively correlated with IOLSAcc (r = 0.541; P = 0.006), subjective accommodation (r = 0.412; P = 0.022), and objective accommodation (r = 0.466; P = 0.045), respectively. Conclusion. LSPilo is an independent preoperative parameter associated with the postoperative Acc-IOL mobility and pseudophakic accommodation. It may offer valuable information for ophthalmologists in determining the suitable candidates for Acc-IOL implantation. PMID:27516899

  5. Patient-reported benefit of ReSTOR® multi-focal intraocular lenses after cataract surgery: Results of Principal Component Analysis on clinical trial data

    Directory of Open Access Journals (Sweden)

    Viala Muriel

    2008-01-01

    Full Text Available Abstract Background Restoration of functional distance and near vision independently of additional correction remains a goal for cataract surgery. ReSTOR®, a new multi-focal intraocular lens (IOL addresses this issue with an improvement in both distance and near vision, often without need for glasses. This analysis attempted to discuss the patient-reported benefit of ReSTOR® using a full but organised representation of data. Methods Two non-randomised, open-label clinical trials conducted in Europe and the United-States were conducted to compare the efficacy of ReSTOR® to AcrySof® mono-focal IOLs. A total of 710 patients in need of bilateral cataract extraction were included in the pooled study. The TyPE, a patient questionnaire, was fully completed by 672 of them before and after each eye surgery. The TyPE, composed of 67 items measuring overall visual functioning in both conditions (with and without wearing glasses, evaluates limitations, troubles and satisfaction in distance and near vision. A principal component analysis (PCA of the TyPE questionnaire was performed on pooled data from baseline and post-surgery observations in order to fully represent the change in the TyPE data over time. ReSTOR® and mono-focal groups were used as illustrative variables. The coordinates of the first 2 factors were compared between visits and between IOLs (ReSTOR® vs. mono-focal, using paired t-tests and t-tests, respectively. Results The first factor of the PCA explained 55% of the variance and represented 'visual functioning and patient satisfaction'. The second factor explained 6% of the variance and was interpreted as 'independence from glasses'. An overall difference in factorial coordinates in both factors was seen between baseline and the first eye surgery, and between the first and the second eye surgery. No difference between ReSTOR® and mono-focal IOL groups was observed at baseline. After surgery, ReSTOR® treated-patients had higher

  6. Closed intraocular microsurgery in ocular trauma.

    Science.gov (United States)

    Kanski, J J

    1978-04-01

    A series of 53 eyes that had suffered severe trauma was treated by closed intraocular microsurgery with vitreous cutters. The cases were divided into three categories: (a) anterior segment reconstruction for traumatic cataracts and post-traumatic pupillary membranes, (b) vitreous haemorrhage with and without retinal detachment, and (c) traumatically dislocated lenses.

  7. Comparison of visual functions and quality of life with aspheric monofocal intraocular lenses and aspheric multifocal intraocular lenses after bilateral cataract surgery%多焦点人工晶状体和单焦点非球面人工晶状体植入术后患者视功能及生存质量比较

    Institute of Scientific and Technical Information of China (English)

    郭别川; 柯敏; 田朕; 韩芳芳

    2014-01-01

    目的 比较植入多焦点人工晶状体(intraocular lens,IOL)和单焦点非球面IOL对单纯白内障患者术后视功能及生存质量的影响.方法 采用前瞻性和回顾性调查研究,共纳入72例(144眼)老年性白内障患者,均行超声乳化联合IOL植入术,其中20例植入折叠式多焦点IOL(多焦点IOL组),52例植入折叠式单焦点非球面IOL(单焦点IOL组),问卷调查并比较患者术前和术后6个月的视功能及生存质量.结果 术后两组患者总体视功能及生存质量之间的差异均无统计学意义(均为P>0.05),但较术前均有提高,差异均有统计学意义(均为P<0.05).在活动能力、社会交际能力和心理健康方面,单焦点非球面IOL植入后却表现出较为明显的优势,差异均有统计学意义(均为P<0.05);多焦点IOL的术后脱镜率明显高于单焦点非球面IOL(P <0.05);而在术后视功能、生存质量的其他具体方面(与视力有关的日常活动限制、周边视野、感觉适应、立体觉和自理能力),两组之间的差异均无统计学意义(均为P >0.05).结论 单焦点IOL和多焦点IOL在改变视功能和生存质量方面总体效果相同,但多焦点IOL在患者脱镜方面有明显优势,而单焦晶状体在价格上表现出比较明显的优势.

  8. 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.

  9. Ophthalmic halo reduced lenses design

    Science.gov (United States)

    Limon, Ofer; Zalevsky, Zeev

    2015-05-01

    The halo effect is a very problematic visual artifact occurring in extended depth of focus or multi-focal ophthalmic lenses such as e.g. intra-ocular (after cataract surgery) or contact lenses when used in dark illumination conditions. This artifact is generated due to surface structures added on top of those lenses in order to increase their depth of focus or to realize multiple focal lengths. In this paper we present novel solution that can resolve this major problem of ophthalmic lenses. The proposed solution involves modification to the surface structure that realizes the extended depth of focus. Our solution is fabricated and numerically and experimentally validated also in preliminary in-vivo trials.

  10. 人工晶体因素对白内障角膜散光患者术后获益的影响%Influence of different intraocular lenses on postoperative benefit of cataract patients with astigmatism

    Institute of Scientific and Technical Information of China (English)

    巨朝娟; 楚妙; 张骞; 林伟

    2015-01-01

    BACKGROUND:Monofocal and multifocal Toric intraocular lens that have been widely used in clinic exhibit xcelent biological and optical characteristics and have good safety and stability after implantation. OBJECTIVE:To compare the outcomes and rotation stability in patients with cataract and astigmatism after implantation of monofocal and multifocal intraocular lens. METHODS:A total of 210 patients with cataract and astigmatism who received phacoemulsification and intraocular lens implantation were included in this study. Of them, 105 patients were assigned to monofocal intraocular lens implantation and the other 105 patients to multifocal intraocular lens implantation. Uncorrected visual acuity, best corrected visual acuity, residual astigmatism were reexamined at 1, 3 weeks and 1 month after surgery. The rotation of Toric intraocular lens was determined. The incidence of complications and spectacles- independent rate were recorded. RESULTS AND CONCLUSION:Visual acuity and residual astigmatism in each group were significantly improved after 1 week of intraocular lens implantation (P < 0.05); furthermore, these two indicators became better over time. Improvement of visual acuity and residual astigmatism in multifocal intraocular lens group was more obvious than that in monofocal intraocular lens group. Postoperative intraocular lens rotation at < 5° occurred in both groups. The intraocular lens rotation degree in multifocal intraocular lens group was higher than that in monofocal intraocular lens group at different time points (P < 0.05). There were no significant differences in incidence of complications and spectacles-independent rates between two groups at 1 month after surgery. These results demonstrate that multifocal Toric intraocular lens provides better visual acuity and residual astigmatism improvement, while monofocal Toric intraocular lens provides better rotation stability.%背景:单焦点与多焦点Toric散光型人工晶体具有良好的生物

  11. Clinical Study on the Visual Quality of Eyes Implanted With AcrySof IQ Aspherical Intraocular Lenses%非球面AcrySof IQ人工晶状体植入术后视觉质量临床研究

    Institute of Scientific and Technical Information of China (English)

    陈迎迎; 谭少健; 梁皓; 刘彦斌

    2012-01-01

    目的 评价非球面人工晶状体(IOL)AcrySof IQ IOL植入术后年龄相关性白内障患者的视觉质量.方法 年龄相关性白内障患者42例55眼,按随机数字表法将患者分成两组.其中非球面人工晶体组24例(28眼),植入AcrySof IQ IOL;球面人工晶体组18例(27眼),植入AcrySof Natural IOL.术后随访3个月的裸眼视力(UCVA)、最佳矫正远视力(BCVA),不同亮度环境下的对比敏感度等.结果 手术后3个月非球面组UCVA为0.76±0.18,优于球面组的0.66±0.17,差异有统计学意义(P<0.05).非球面组BCVA为0.85±0.19,优于球面组的0.74±0.19,差异有统计学意义(P<0.05).两组球镜、柱镜差异无统计学意义(P>0.05).在明视觉条件下,非球面组在12.0 cpd、18.0 cpd的对比敏感度明显优于球面组(P<0.01).在暗视觉条件下非球面组所有空间频率的对比敏感度非球面组均优于球面组(P<0.05).非球面组眩光、光晕等的发生率均低于球面组(P<0.05).结论 白内障术后早期,非球面人工晶状体能够提供较好的术后裸眼视力、最佳矫正远视力、亮环境下高频对比敏感度和暗环境下的所有空间频率的对比敏感度,提示非球面人工晶状体能够提供较好的视觉质量.%Objective To evaluate the visual quality of eyes implanted with AcrySof IQ aspherical intraocular lenses( IOLs ). Methods Forty-two patients( 55 eyes ) with age-related cataracts were enrolled in the study, who were randomly divided into two groups according to random number table. Phacoemulsification and IOL implantation were applied to patients with aspherical IOLs( AcrySof IQ ) in 28 eyes and spherical IOLs( AcrySof Natural IOL ) in 27 eyes, respectively. All patients were followed up for 3 months. The examinations included uncorrected visual acuity ( UCVA ),best corrected visual acuityC BCVA ),contrast sensitivity( Functional Acuity Contrast Test ),and questionnaires were applied on the 3rd month after operation

  12. Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.

    Science.gov (United States)

    Pintwala, Robert; Postnikoff, Cameron; Molladavoodi, Sara; Gorbet, Maud

    2015-03-01

    Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal biocompatibility, specifically through the quantification of cell-surface markers of leukocyte activation.

  13. 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.

  14. Binocular clinical comparison study of Tecnis multifocal aspheric and monofocal spherical intraocular lenses%双眼植入Tecnis多焦点和单焦点球面人工晶状体的临床比较研究

    Institute of Scientific and Technical Information of China (English)

    叶盼盼; 姚克; 李霞; 吴炜; 黄晓丹; 俞一波

    2010-01-01

    pseudophakic patients with bilateral implantation of Tecnis multifocal aspheric and conventional monofocal spherical intraocular lenses (IOL). Methods A prospective study of 100 consecutive cases (200 eyes) was conducted. All cataract patients underwent phaocoemulsification were randomized to receive multifocal aspheric IOL ( Tecnis ZM900, AMO, multifocal aspheric group) or conventional spherical IOL ( Akreos Adapt, Bausch&Lomb, monofocal spherical group) . The following investigations were performed to assess the uncorrected and distance-corrected visual acuity of distance, intermediate and near distances, accommodative amplitude, spherical aberrations of total eye, contrast sensitivity, glare sensitivity and near stereoacuity. Patients were surveyed for visual disturbances and lifestyle visual quality. The independent-samples t test waa used to compare the measure data which met normal distribution and the Mann-Whitney U test was used to compare the measure data which didn' t meet. The chi-square test was applied to compare categorical variables. Results The uncorrected and distance-corrected bilateral visual acuity of multifocal aspheric group at 30 cm and 40 cm were 0. 24 ± 0. 12 and 0. 22 ± 0. 11 (logMAR) , better than monofocal spherical group ( Z = - 8. 261, P = 0. 000;Z = -5. 508, P =0.000), but the visual acuity at other distances had no statistical difference between two groups. Patients with multifocal aspheric IOL had significantly higher accommodative amplitude than those with monofcal spherical IOL, improved about 2. 3 - 2. 8 D ( Z= -10. 655, P = 0. 000; Z =- 2. 709, P = 0. 007). Mean spherical aberration of multifocal aspheric group was ( 0. 027 ±0. 160) μm and (0. 006 ±0. 083)μm, significantly lower than that of monofocal spherical group (0. 269 ±0. 161) μm, (0.037 ±0.205) μm at 5 mm and 3 mm pupil diameter(Z= - 8. 815, P = 0. 000; Z = -2. 791, P = 0. 005) . The difference of contrast sensitivity was not significant, but glare sensitivity was higher

  15. Radiation sensitive acrylate composition

    International Nuclear Information System (INIS)

    This application relates to radiation-sensitive compositions and more particularly to such compositions comprising acrylated esters. As used in this specification, the term acrylated esters refers to either acrylic or methacrylic acid resins. 3 tabs

  16. 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.

  17. Controversies in intraocular lens implantation in pediatric uveitis.

    Science.gov (United States)

    Phatak, Sumita; Lowder, Careen; Pavesio, Carlos

    2016-12-01

    Cataract is one of the most common and visually debilitating complications of pediatric uveitis. It develops as a consequence of chronic inflammation and steroid use and is seen most often in juvenile idiopathic arthritis (JIA)-associated uveitis. Cataract extraction with intraocular lens (IOL) insertion has been carried out with a measure of success in non-uveitic pediatric eyes, but in cases of uveitis, multiple factors affect the final outcome. Chronic inflammation and its sequelae such as band keratopathy, posterior synechiae, and cyclitic membranes make surgical intervention more challenging and outcome less certain. Postoperative complications like increased inflammation, glaucoma, posterior capsular opacification, retrolental membranes, and hypotony may compromise the visual outcome. Early refractive correction is imperative in pediatric eyes to prevent amblyopia. The use of contact lenses and intraocular lenses in pediatric uveitic eyes were fraught with complications in the past. Surgical interventions such as vitreo-lensectomy followed by contact lens fitting and small incision cataract surgery followed by different types of intraocular lenses have been utilized, and many reports have been published, albeit in small patient groups. This review analyzes and discusses the existing literature on intraocular lens implantation in cases of pediatric uveitic cataract surgery. PMID:27009616

  18. Controversies in intraocular lens implantation in pediatric uveitis.

    Science.gov (United States)

    Phatak, Sumita; Lowder, Careen; Pavesio, Carlos

    2016-12-01

    Cataract is one of the most common and visually debilitating complications of pediatric uveitis. It develops as a consequence of chronic inflammation and steroid use and is seen most often in juvenile idiopathic arthritis (JIA)-associated uveitis. Cataract extraction with intraocular lens (IOL) insertion has been carried out with a measure of success in non-uveitic pediatric eyes, but in cases of uveitis, multiple factors affect the final outcome. Chronic inflammation and its sequelae such as band keratopathy, posterior synechiae, and cyclitic membranes make surgical intervention more challenging and outcome less certain. Postoperative complications like increased inflammation, glaucoma, posterior capsular opacification, retrolental membranes, and hypotony may compromise the visual outcome. Early refractive correction is imperative in pediatric eyes to prevent amblyopia. The use of contact lenses and intraocular lenses in pediatric uveitic eyes were fraught with complications in the past. Surgical interventions such as vitreo-lensectomy followed by contact lens fitting and small incision cataract surgery followed by different types of intraocular lenses have been utilized, and many reports have been published, albeit in small patient groups. This review analyzes and discusses the existing literature on intraocular lens implantation in cases of pediatric uveitic cataract surgery.

  19. Comparison of shape recovery ratios in various intraocular lens haptics.

    Science.gov (United States)

    Kimura, W; Kimura, T; Sawada, T; Kikuchi, T; Toda, H; Yamada, Y; Nagai, H

    1992-11-01

    Since understanding the mechanical properties of intraocular lens (IOL) haptic materials can minimize decentration after surgery, we have examined shape recovery ratios of various intraocular lens haptics (polypropylene [PP], polyvinylidene fluoride [PVDF], extruded poly(methyl methacrylate) [PMMA]) currently on the market under conditions that approximate clinical use. The results using various Ascon lens-holding forceps and compression tests, during which the lenses were held in a cylindrical holder for seven days, one month, and three months, indicated that PVDF haptics had better shape recovery capability than PP and extruded three-piece PMMA haptics.

  20. Development and experimental verification of an intraocular scattering model

    Science.gov (United States)

    Jiang, Chong-Jhih; Jhong, Tian-Siang; Chen, Yi-Chun; Sun, Ching-Cherng

    2011-10-01

    An intraocular scattering model was constructed in human eye model and experimentally verified. According to the biometric data, the volumetric scattering in crystalline lens and diffusion at retina fundus were developed. The scattering parameters of cornea, including particle size and obscuration ratio, were varied to make the veiling luminance of the eye model matching the CIE disability glare general formula. By replacing the transparent lens with a cataractous lens, the disability glare curve of cataracts was generated and compared with that of transparent lenses. The MTF of the intraocular scattering model showed nice correspondence with the data measured by a double-pass experiment.

  1. Bilateral Primary Intraocular Lymphoma

    Directory of Open Access Journals (Sweden)

    Mehrdad Karimi

    2011-01-01

    Full Text Available Purpose: To report a case of bilateral primary intraocular lymphoma. Case report: A 33-year-old man presented with bilateral blurred vision since two years ago. Examination revealed large keratic precipitates, anterior chamber reaction, posterior subcapsular cataracts, and vitreous infiltration. After a short trial of topical and periocular steroids, diagnostic 25-gauge pars plana vitrectomy was performed and cytologic evaluation of the aspirate confirmed a diagnosis of intraocular lymphoma. The patient was subsequently managed with intravitreal methotrexate in both eyes and responded favorably. Central nervous system workup for lymphoma was negative. Conclusion: Primary intraocular lymphoma should be considered in young adults suffering from chronic recalcitrant panuveitis.

  2. 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

    OpenAIRE

    Raul de Camargo Vianna Filho; Lincoln de Freitas; Norma Allemann; Ana Luísa Hofling de Lima

    2000-01-01

    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 a...

  3. Bilateral Primary Intraocular Lymphoma

    OpenAIRE

    Mehrdad Karimi; Masoud Soheilian; Mozhgan Rezaei Kanavi

    2011-01-01

    Purpose: To report a case of bilateral primary intraocular lymphoma. Case report: A 33-year-old man presented with bilateral blurred vision since two years ago. Examination revealed large keratic precipitates, anterior chamber reaction, posterior subcapsular cataracts, and vitreous infiltration. After a short trial of topical and periocular steroids, diagnostic 25-gauge pars plana vitrectomy was performed and cytologic evaluation of the aspirate confirmed a diagnosis of intraocular lympho...

  4. Bilateral intraocular dirofilariasis

    Directory of Open Access Journals (Sweden)

    Viney Gupta

    2014-01-01

    Full Text Available Ocular dirofilariasis mostly presents as a subconjunctival or eyelid lesion. [1] Intraocular dirofilarial infestation is rare. [2],[3] We report a case of a young woman who was accidentally detected to have a live motile worm in the anterior segment in one eye and a cystic lesion on the optic disc in the other eye. To our knowledge, bilateral intraocular dirofilariasis has never been reported.

  5. Misdiagnosis induced intraocular lens dislocation in anterior megalophthalmos

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-wei; XU Wen; ZHU Ya-nan; LI Jin-yu; ZHANG Li; YAO Ke

    2012-01-01

    Anterior megalophthalmos (AM) is an uncommon developmental anomaly of the anterior segment of the eye with a constellation of findings that includes enlarged cornea,deep anterior chamber,posterior positioning of the iris and lens,iris stroma atrophy,hypoplasia of iris dilator,pupil displacement,large capsular bag,lens subluxation,prematurely cataract and the tendency to retinal detachment.AM,especially when symptoms are mild,is not an easy disease to diagnose.We present 3 AM cases that were misdiagnosed as congenital cataract with weak zonule and megalocornea.Intraocular lenses (IOLs) dislocated after standard cataract surgeries and subsequent surgery (replacing the dislocated IOLs with iris-claw intraocular lenses) achieved satisfactory outcome.Although rare,AM should be included in the differential diagnosis of enlarged cornea and we recommend implanting Artisan lens in AM patients.

  6. Phacoemulsification and intraocular lenses implanted for super high myopia combined cataract%超声乳化联合人工晶体植入治疗超高度近视白内障疗效观察

    Institute of Scientific and Technical Information of China (English)

    董立红

    2012-01-01

    目的 观察超声乳化联合人工晶体植入治疗超高度近视白内障的疗效及安全性.方法 60例共98眼超高度近视白内障患者,按眼轴长度分为3组,I组眼轴长度(27.00~29.59)mm 35只眼,Ⅱ组眼轴长度(29.60~32.19)mm 30只眼,Ⅲ组眼轴长度(32.20~34.70)mm 33只眼,均采用超声乳化联合人工晶体植入术治疗.结果 术后3个月最佳校正视力≤0.1者7眼(7.14%),0.2~0.4者19眼(19.39%),≥0.5者72眼(73.47%).其中≥0.5者I组34眼(97.14%),Ⅱ组23眼(76.67%),Ⅲ组15眼(45.45%).结论 超声乳化联合人工晶体植入治疗超高度近视白内障可以充分矫正屈光不正,解除光传导通路障碍,提高视力,手术并发症少,是一种安全、有效的方法.%Objective To observe the therapeutic effect of phacoemulsificafion with intraocular lens ( IOL ) implantation for cataract with hish myopia. Methods Sixty patients ( 98 eyes ) with cataract associated with high myopia received phacoemulsification and IOL implantation. They were divided into 3 groups according to ocular axial length, patients in group I with ocular axial length at 27. 00 ~ 29. 59 mm in 35 eyes, patients in group II with ocular axial length at 29. 60 ~32.19 mm in 30 eyes, and patients in group III with ocular axial length at 32. 20 ~ 34.70 mm in 33 eyes. The visual acuity of patients was examined on preoperative day and three months after operation. Results Postoperative vi-sualacuity:BCVAS0.1 in 7 eyes(7.14% ), 0.2-0.4 in 19 eyes( 19.39% ), SO. 5 in 72 eyes(73.47% ), Among BCVA&0. 5 patient, 34 eyes (97.14% ) in I group, 23 eyes ( 76.67% ) in II group, 15 eyes ( 45.45% ) in 111 group. Conclusion Phacoemulsification with and intraocular lens implantation significantly improves visual acuity in patients with cataract and high myopia.

  7. Symbolic algebra approach to the calculation of intraocular lens power following cataract surgery

    Science.gov (United States)

    Hjelmstad, David P.; Sayegh, Samir I.

    2013-03-01

    We present a symbolic approach based on matrix methods that allows for the analysis and computation of intraocular lens power following cataract surgery. We extend the basic matrix approach corresponding to paraxial optics to include astigmatism and other aberrations. The symbolic approach allows for a refined analysis of the potential sources of errors ("refractive surprises"). We demonstrate the computation of lens powers including toric lenses that correct for both defocus (myopia, hyperopia) and astigmatism. A specific implementation in Mathematica allows an elegant and powerful method for the design and analysis of these intraocular lenses.

  8. 折叠式人工晶状体囊袋内植入后偏心与倾斜的临床研究%Decentration and tilt of foldable intraocular lenses in the lens capsule

    Institute of Scientific and Technical Information of China (English)

    方艳文; 卢奕; 汪琳

    2008-01-01

    目的 比较目前临床上常用的四种折叠式人工晶状体(intraocular lens,IOL)在囊袋内植入后偏心与倾斜的差异.方法 对65例/眼单纯性白内障患者进行术后3个月的随访.这些患者分别植入了一体式疏水丙烯酸酯IOL(SA60AT,Alcon)、三体式疏水丙烯酸酯IOL(AR40e,AMO)、三点固定式亲水丙烯酸酯IOL(XISTABI,IOLTECH)及四点固定式亲水丙烯酸酯IOL(QUATTRO SE,Corneal).用眼前节成像系统Pentacam(Oculus) 集各眼的Scheimpflug图像,用图像分析的方法得出IOL的偏心值与倾斜度.结果 SA60AT、AR40e、XLSTABI、QUATTRO SE四组患者IOL的平均偏心值分别为(281.49±169.58)ìm、(346.35±177.08)ìm、(531.33±254.70)ìm、(360.59±185.91)ìm,其差异有显著统计学意义(P=0.0100).四组患者IOL的倾斜度的中位数分别为0.98°(0.70°~1.73°)、1.33°(0.86°~1.83°)、1.50°(0.80°~2.68°)、1.38°(0.94°~2.37°),其差异无统计学意义(P=0.3885).四组患者的最佳矫正视力和对比敏感度差异无统计学意义(P>0.05).结论 四种IOL囊袋内植入后在倾斜度方面无差异,而在居中性方面,SA60AT优于XLSTABI,其他各种IOL间两两比较均无明显差异.

  9. Synthesis of acrylic prepolymer

    International Nuclear Information System (INIS)

    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)

  10. 非球面人工晶状体在个体化人眼模型中成像质量的研究%Optical quality of aspheric intraocular lenses in individual eye models

    Institute of Scientific and Technical Information of China (English)

    南莉; 汤欣; 刘永基

    2011-01-01

    Objective An aspheric intraocular lens (IOL) with fixed spherical aberration (SA) implanted in an individual patient will not always obtain ideal optical quality since human corneal structure and SA have large individual variations.The aim of this research was to study optical performance of individual pseudophakic eye models that were constructed based on individual anatomic parameters and implanted IOL with different optical designs.Methods Computer numerical simulation experiment.The anatomic parameters of individual pseudophakic patients were obtained by Pentacam and IOL Master.Parameters were input into ZEMAX to build individual eye models.Three aspheric IOL (SofPort AO,Tecnis Z9000,FY60AD) and one spherical IOL (YA60BBR) were implanted into individual eye models.Modulation transfer function (MTF) and contrast sensitivity function (CSF) were calculated for 3 mm to 5 mm pupil diameters and 550 nm wavelength.Results The height of the MTF and CSF curves were decreased with larger pupils.They were similar with the 4 IOL implanted in the individual eye models for 3 mm pupil diameter,but they were different from each other for 4 and 5 mm pupils,indicating that individual people with different anatomic structures need certain types of IOL to obtain optimal optical performance.This phenomenon was more pronounced for larger pupil.Conclusion The individual eye model based on an individual patient's anatomic parameters should mimic the optical performance of an individual's eye.The type of IOL is varied to obtain optimal optical performance for the optical system of the human eye with different anatomic structures.We should choose an IOL based on the individual eye's structure to obtain optimal retinal image clinically.%目的 根据不同患者眼部解剖参数建立个体化眼模型,研究植入不同设计的人工晶状体(IOL)后的光学表现.方法 计算机数字模拟实验.采用Pentacam眼前节分析系统、IOL Master采集白内障摘除联合IOL植入

  11. Meta - analysis of clinical randomized controlled trials comparing ReZOOM with ReSTOR multifocal intraocular lenses in cataract surgery%ReZOOM与ReSTOR多焦点人工晶状体应用效果的Meta分析

    Institute of Scientific and Technical Information of China (English)

    邵德望; 杨春燕; 陈威; 王华; 刘兵

    2014-01-01

    AIM: To systematic review the effectiveness of refractive multifocal intraocular lens ( MIOL ) ReZOOM vs diffractive MIOL ReSTOR in the treatment of cataract. METHODS: Randomized controlled trials comparing refractive MIOL ReZOOM with diffractive MIOL ReSTOR were identified by searching CENTRAL, MEDLINE, EMbase, WANFANG MED ONLINE, CMJD, SinoMed, and CNKI. Related journals also were hand-searched. Methodological quality of randomized controlled trials ( RCTs ) was evaluated by simple evaluate method that recommended by the Cochrane Collaboration. Data extracted by two reviewers with designed extraction form. RevMan software ( release 5. 2 ) was used for data management and analysis. RESULTS:A total of 7 trials (846 eyes) were included for systematic review. Subgroup analyses were used according to different model comparison of ReSTOR MIOL. The results showed a significant difference in the mean of the best distance corrected intermediate visual acuity ( BDCIVA) in the ReZOOM MIOL group with WMD=-0.11, 95% CI (-0.16, -0.06) (P CONCLUSION: Patients implanted with ReZOOM MIOL can provide better BDCIVA; patients implanted with ReSTOR MIOL show better UCNVA, are less likely to appear light halo, glare and other visual adverse reactions; correction in spectacles cases, patients implanted with ReZOOM or ReSTOR MIOL have considerable performances in the far and near visual acuity.%方法:计算机检索 CENTRAL、MEDLINE、EMbase、万方医学网数据库、维普中文生物医学期刊全文数据库、中国生物医学文献数据库、中国期刊全文数据库,手工检索相关会议文献,纳入所有ReZOOM与ReSTOR对照的超声乳化白内障吸出联合 IOL 植入的随机对照试验。采用Cochrane系统评价方法,由两名评价员分别提取资料,评价方法学质量后,应用RevMan 5.2软件进行Meta分析。结果:共纳入7个随机对照试验(846眼)。结果显示:裸眼远视力:ReZOOM组与ReSTOR组间差异无统计学意义[WMD=-0

  12. Estimation of visual performance of two diffractive multifocal intraocular lenses%两种常用衍射型多焦点人工晶状体的视觉评估

    Institute of Scientific and Technical Information of China (English)

    季樱红; 卢奕; 汪琳; 蒋永祥

    2010-01-01

    Objective To evaluate the visual performance after implantation of the Tecnis ZM900 multifocal intraocular lens (IOL) ( TMF) and the Restor SA60D3 multifocal IOL (Restor). Methods In a prospective study, TMF or Restor was implanted randomly in 73 patients (90 eyes) . The following parameters were assessed 3 months after surgery: refraction, uncorrected and best corrected visual acuities (VA) for distance, intermediate, near and different contrast levels, reading ability, pupil size, wave-front error, defocus curve and position of IOL Patient satisfaction (overall satisfaction, spectacle independence, photic phenomena) was assessed by a questionnaire. The chi-square test was applied to compare categorical variables and Mann-Whitney U test was used to compare the measured data. Results The uncorrected, best corrected and/or distance-corrected VA for distance, intermediate, near and different contrast levels did not show statistically significant differences between the two groups (P > 0. 05 ). Near reading acuity and reading speed were better in TMF under low-light conditions (Z= -2.579, P=0.009; Z = -5.244, P=0.000). The curve of defocus showed that TMF had significantly better intermediate distance (at 50 cm) (Z = -5.300, P = 0.000) and worse near distance (from 25 to 28 cm) than those of Restor (Z= -3.745, P = 0. 000; Z= -5. 691, P=0. 000). Measurements under pupil diameter at 3. 0 mm and 5. 0 mm, ocular and intraocularZ (4, 0) were significantly lower (Z = -8.175, P = 0.000; Z= -5.210, P=0.000andZ = -4.453, P=0.000; Z= -3.790, P = 0.000) , the values of PSF Strehl Ratio and MTF AreaRatio A/D were significantly higher (Z = - 3. 047, P = 0. 002; Z = - 3. 672, P = 0. 008 and Z = - 2. 038, P = 0.042; Z = -2.579, P =0.009) in TMF than those in Restor. On the questionnaire, there was no difference of overall satisfaction, spectacle independence and photic phenomena (P > 0.05 ). Conclusions Implantation of the TMF and Restor offers excellent distant and near VA. Restor

  13. Ophthalmic Lenses

    CERN Document Server

    Bhootra, Ajay Kumar

    2009-01-01

    This book is uniquely meant for the ophthalmologists, optometrists and opticians to help the world see better by excellent vision through the services of technicians and clinical principle based ophthalmology so that the management of ocular problems can be done for a better vision . Informs that a wide range of material and design of ophthalmic lenses with innovative developments is available. This book presents comprehensively rich information about the ophthalmic lenses and their dispensing tips . It will be highly useful mainly for the students of optometry and opticians, ophthalmologists,

  14. Intraocular Lens Calcification; a Clinicopathologic Report

    Directory of Open Access Journals (Sweden)

    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.

  15. Intraocular lens implantation for the treatment of astigmatism%人工晶状体植入术矫正散光

    Institute of Scientific and Technical Information of China (English)

    施俊廷; 徐雯

    2013-01-01

    Refractive intraocular lens surgery can be used for the treatment of moderate and high regular astigmatism.Refractive intraocular lens surgery includes aphakic intraocular lens surgery and phakic intraocular lens surgery.In phakic intraocular lens surgery two types of intraocular lenses are used:iris-claw intraocular lens and posterior chamber intraocular lens.The purpose of this article is to review current knowledge of surgical treatments of astigmatism with a particular focus on toric implantable collamer lenses.%人工晶状体(IOL)植入术能矫正中、高度规则散光.矫正散光的IOL植入术可分为无晶状体眼及有晶状体眼的环曲面IOL植入两类,其中有晶状体眼的环曲面IOL又可分为虹膜夹持型及后房型.本文旨在介绍IOL矫正散光的手术治疗方法,并着重介绍有晶状体眼植入后房型IOL矫正屈光不正合并散光的治疗技术.

  16. Smart lenses

    International Nuclear Information System (INIS)

    If you wear glasses and want to protect your eyes from harmful ultraviolet rays when you step outside into the bright sunshine, you can do a number of things. You can switch to a pair of prescription sunglasses or don some clip-on shades. Alternatively, you can invest in a pair of glasses with 'photochromatic' lenses, which go dark in strong sunlight. Such lenses are said to be 'smart' because they can adapt to their environment without human intervention. An example of a more complex smart system is the adaptive optics used by astronomers to image faint objects. The system compensates for the distorting effect of the atmosphere by first measuring how much a uniform light wavefront is perturbed and then applying an opposite distortion, usually by making the appropriate changes to a deformable mirror. Now, physicists are starting to develop 'adaptive lenses' made from liquids or soft polymer materials that can change their focal length in response to external stimuli. At varying degrees of commercialization, these devices hold great promise in imaging applications where space is at a premium, from mobile-phone cameras to surgical endoscopes. In the November issue of Physics World, Hongrui Jiang and Liang Dong take a look at different methods of producing smart lenses, including 'responsive hydrogels' that focus when given different chemical, biological or physical stimuli. (U.K.)

  17. Iris-fixated anterior chamber phakic intraocular lens for myopia moves posteriorly with mydriasis.

    NARCIS (Netherlands)

    Cruysberg, L.P.J.; Doors, M.; Berendschot, T.T.; Brabander, J. De; Webers, C.A.; Nuijts, R.M.

    2009-01-01

    PURPOSE: To elucidate the physiological characteristics of eyes implanted with iris-fixated anterior chamber phakic intraocular lenses (pIOLs), which are increasingly being used for the correction of higher myopic and hyperopic refractive errors. METHODS: In a case series of 20 patients (39 eyes), t

  18. CORRECTION OF HIGH MYOPIA WITH THE WORST MYOPIA CLAW INTRAOCULAR-LENS

    NARCIS (Netherlands)

    LANDESZ, M; WORST, JGF; SIERTSEMA, JV; VANRIJ, G

    1995-01-01

    BACKGROUND: Phakic anterior chamber lenses is one of the modalities used to correct high myopia, We report the initial results of our prospective study on the Worst myopia claw intraocular lens (IOL) that is fixated to the anterior iris, METHODS: We studied 35 eyes in 18 patients with a preoperative

  19. Intraocular lens exchange-removing the optic intact

    Science.gov (United States)

    Lee, Matthew Hao; Webster, Diane Lesley

    2016-01-01

    Current practice for intraocular lens (IOL) exchange is to cut the optic of the posterior chamber intraocular lens (PCIOL) prior to removing it. Great care must be taken during this maneuver to avoid a posterior capsular tear. Removing the haptics from the fibrosed capsule can also be hazardous, as it may result in zonular stress and dehiscence. A technique is described for performing foldable (one-piece acrylic) IOL removal without cutting the optic. Careful visco-dissection of the haptics with a low viscosity ophthalmic viscosurgical device (OVD) in the fibrosed peripheral capsular tunnel avoids zonular or capsular stress. Internal wound enlargement permits foldable IOL removal in one piece, whilst preserving a self-sealing sutureless corneal wound. This technique may enhance the safety and efficacy of foldable IOL exchange. PMID:27366699

  20. Intraocular lens exchange-removing the optic intact.

    Science.gov (United States)

    Lee, Matthew Hao; Webster, Diane Lesley

    2016-01-01

    Current practice for intraocular lens (IOL) exchange is to cut the optic of the posterior chamber intraocular lens (PCIOL) prior to removing it. Great care must be taken during this maneuver to avoid a posterior capsular tear. Removing the haptics from the fibrosed capsule can also be hazardous, as it may result in zonular stress and dehiscence. A technique is described for performing foldable (one-piece acrylic) IOL removal without cutting the optic. Careful visco-dissection of the haptics with a low viscosity ophthalmic viscosurgical device (OVD) in the fibrosed peripheral capsular tunnel avoids zonular or capsular stress. Internal wound enlargement permits foldable IOL removal in one piece, whilst preserving a self-sealing sutureless corneal wound. This technique may enhance the safety and efficacy of foldable IOL exchange.

  1. Phakic Intraocular lens- a review

    OpenAIRE

    Cruz, Francisco Miguel

    2015-01-01

    Introduction: Intraocular refractive procedures with the implantation of a Phakic Intraocular lens have become a safe efficient and predictable alternative for treating high ametropias when the use of corneal photoablative procedures is not possible. The implantation of Phakic intraocular lens preservs the accomodative function,is a reversable refractive procedure, with minimal induction of higher order aberrations compaed with corneal photoablative procedures. Methods: An analytical review o...

  2. Ectopic intraocular lens: An unusual complication of cataract surgery

    Directory of Open Access Journals (Sweden)

    Mehul A Shah

    2014-01-01

    Full Text Available We wish to report an unusual complication of intraocular lens (IOL insertion following uneventful phacoemulsification. After successful phacoemulsification surgery, a hydrophobic acrylic IOL was loaded in the injector for insertion into the capsular bag. During insertion, the IOL inadvertently extended into the corneal stromal lamella. The complication was recognized at a late stage, and the foldable acrylic lens was retrieved and reinserted correctly in the bag. The anterior chamber was made viscoelastically taut and was maintained in this state for 10 min, followed by a routine viscoelastic wash and air bubble injection. Cornea was slightly edematous with stromal haze, and the corneal thickness was 908 μm. At the 1-month follow-up visit, the patient′s vision was 20/40, the stromal haze had subsided, the corneal thickness was 572 μm, and the patient was comfortable. Though it was unknown complication, following proper management patient recovered satisfactorily.

  3. 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.

  4. Silicone/Acrylate Copolymers

    Science.gov (United States)

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

  5. Contact Lenses for Vision Correction

    Science.gov (United States)

    ... Ask an Ophthalmologist Español Eye Health / Glasses & Contacts Contact Lenses Sections Contact Lenses for Vision Correction Proper ... to Know About Contact Lenses Colored Contact Lenses Contact Lenses for Vision Correction Written by: Kierstan Boyd ...

  6. IOL Implants: Lens Replacement and Cataract Surgery (Intraocular Lenses)

    Science.gov (United States)

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ...

  7. Extended drug delivery by contact lenses for glaucoma therapy.

    Science.gov (United States)

    Peng, Cheng-Chun; Burke, Michael T; Carbia, Blanca E; Plummer, Caryn; Chauhan, Anuj

    2012-08-20

    We combine laboratory-based timolol release studies and in vivo pharmacodynamics studies in beagle dogs to evaluate the efficacy of glaucoma therapy through extended wear contact lenses. Commercial contact lenses cannot provide extended delivery of ophthalmic drugs and so the studies here focused on increasing the release duration of timolol from ACUVUE TruEye contact lenses by incorporating vitamin E diffusion barriers. The efficacy of timolol delivered via extended wear contact lenses was then compared to eye drops in beagle dogs that suffer from spontaneous glaucoma. The lenses were either replaced every 24h or continuously worn for 4 days, and the pharmacodynamics effect of changes in the intraocular pressure (IOP) of timolol from the ACUVUE TruEye contact lenses can be significantly increased by incorporation of vitamin E. The in vivo studies showed that IOP reduction from baseline by pure contact lens on daily basis was comparable with that by eye drops but with only 20% of drug dose, which suggested higher drug bioavailability for contact lenses. In addition, by inclusion of vitamin E into the lenses, the IOP was reduced significantly during the 4-day treatment with continuous wear of lens.

  8. Neutrino Lensing

    Institute of Scientific and Technical Information of China (English)

    LUO Xin-Lian

    2009-01-01

    Due to the intrinsic properties of neutrinos, the gravitational lens effect for a neutrino should be more colorful and meaningful than the normal lens effect of a photon. Other than the experiments operated at terrestrial laboratory, in principle, we can propose a completely new astrophysical method to determine not only the nature of the gravity of lens objects but also the mixing parameters of neutrinos by analyzing neutrino trajectories near the central objects.However, the angular, energy and time resolution of the neutrino telescopes are still comparatively poor, so we just concentrate on the two classical tests of general relativity, i.e.the angular deflection and the time delay of the neutrino by a lens object as a preparative work in this paper.In addition, some simple properties of neutrino lensing are investigated.

  9. Clinical observation of foldable intraocular lenses in ciliary sulcus suture fixation with Ultrasound biomicroscope-guided%超声生物显微镜引导下折叠人工晶状体睫状沟缝线固定术临床观察

    Institute of Scientific and Technical Information of China (English)

    王胜男; 吕勇

    2013-01-01

    Objective To evaluate the clinical effectiveness of foldable intraocular lenses in ciliary sulcus suture fixation with ultrasound biomicroscope-guided,for clinical application.Methods This study was performed on 37 eyes in 34 patients who needed a foldable intraocular lens in ciliary sulcus suture fixation surgery.A total of 19 eyes in 18 patients had a ultrasound biomicroscope (UBM) examination to ensure the ciliary sulcus localization before the surgery (Group Ⅰ).A total of 18 eyes in 16 patients didn't have a UBM examination (Group Ⅱ).After the surgery,the visual acuity,contrast sensitivity,UBM were checked up in both groups.The results were analyzed by SPSS17.0 statistical software.Results The mean suture position in group Ⅰ was significantly less than that of the group Ⅱ (P <0.001,t-test).The UBM examination showed that the IOL decentration,the optic tilt and the rate of haptics located in the sulcus were statistically significant between the 2 groups.The uncorrected visual acuity (UCVA) 3 months after operation had statistical significance between the 2 groups.But the best corrected visual acuity (BCVA) and the contrast sensitivity function in 3cpd,6cpd,12cpd and 18cpd spatial frequencies 3 months after operation had no significant difference between the 2 groups.Conclusions The use of UBM can help the surgeon identify the ciliary sulcus more precisely,and reduce the tilt and decentration of the IOL,which is conducive to upgrade the operated effect.%目的 通过对比性临床观察,评价超声生物显微镜(UBM)引导下定位睫状沟,行折叠人工晶状体睫状沟缝线固定术的手术效果,为临床应用提供依据.方法 临床病例对照研究.对2010年4月至2012年1月在郑州大学第一附属医院眼科将34例(37只眼)需行人工晶状体睫状沟缝线固定术的患者按术前应用UBM检查和未用UBM检查分为两组:1组18例19只眼,术前行UBM检查,定位睫状沟在巩膜表面投影位置,

  10. Intraocular coenurosis: a case report.

    OpenAIRE

    Ibechukwu, B. I.; Onwukeme, K. E.

    1991-01-01

    A case of intraocular coenurosis was clinically diagnosed and treated with praziquantel. The drug destroyed the coenurus, but vision was lost through toxic endophthalmitis and retinal detachment. There were no systemic side effects.

  11. Opacificação tardia de lente intra-ocular de polimetilmetacrilato (PMMA: relato de caso Late opacification of a polymethylmethacrylate (PMMA intraocular lens: case report

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2005-10-01

    Full Text Available O implante das lentes intra-oculares foi grande avanço na reabilitação visual de pacientes submetidos à cirurgia de extração da catarata. Contudo, os materiais utilizados na fabricação destas lentes, apesar de terem boa biocompatibilidade, são passíveis de alterações posteriores ao implante. No presente estudo, os autores relatam um caso raro de opacificação tardia de lente de polimetilmetacrilato, material inerte e bem tolerado intra-ocularmente, discutindo aspectos importantes no manejo desta complicação, bem como indicação de explante e substituição da lente.The use of intraocular lenses was a great advance in visual recovery after cataract surgery. Although usually with good biocompatibility, some alterations in the intraocular lens material may occur after implantation. Polymethylmethacrylate was the first intraocular lens material to be used on a large scale and assumed to be inert and well-tolerated. We present a rare case of late opacification of a polymethylmethacrylate lens, discussing important aspects of its management such as the indication for intraocular lens exchange.

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

    Science.gov (United States)

    Simon, V.; Radu, T.; Vulpoi, A.; Rosca, C.; Eniu, D.

    2015-01-01

    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.

  13. Laser-triggered intraocular implant to induce photodynamic therapy for posterior capsule opacification prevention.

    Science.gov (United States)

    Zhang, Zhaoguo; Huang, Wenyong; Lei, Ming; He, Yuanfeng; Yan, Mina; Zhang, Xuefei; Zhao, Chunshun

    2016-02-10

    Posterior capsule opacification (PCO) is one of the main reasons for loss of vision again after cataract surgery. In this study, intraocular lenses were modified with indocyanine green (ICG) and sealed up with PLGA to form long-term intraocular implants (ICG-IOL). When triggered by laser, ICG-IOL would induce photodynamic therapy (PDT). In-vitro cell viability assay and scratch wound healing assay demonstrated that ICG-IOL could effectively inhibit HLEpiC proliferation and migration without causing damage to the cells far away from it. Laser attenuation test indicated that ICG-IOL could be applied in vivo. In-vivo pharmacodynamics and safety study showed that ICG-IOL could significantly prevent the occurrence of PCO and was safe for intraocular normal tissue. All these results suggested that ICG-IOL would be a very promising candidate for PCO prevention.

  14. The Effect of Phacoemulsification with Posterior Chamber Intraocular Lens Implantation on Intraocular Pressure and Anterior Chamber Depth

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Mohamadi

    2013-12-01

    Full Text Available Purpose: To evaluate intraocular pressure (IOP and anterior chamber depth (ACD change after phacoemulsification with posterior chamber intraocular lens implantation Methods: In this quasi-experimental study, 84 patients with senile cataract were included. All patients had normal IOP. Patients with traumatic and complicated cataract, any history of uveitis, glaucoma, or other ocular disease or surgery were excluded. Patients underwent phacoemulsification and intraocular lens implantation by the same surgeon. IOP, ACD, and lens thickness were measured and recorded before surgery. IOP was measured at 4, 8 and 12 postoperative weeks and ACD was measured 12 weeks after surgery. Results: The mean preoperative ACD significantly increased from 2.93 mm to 3.54 mm postoperatively (p<0.0001. Mean preoperative IOP was 16.06 mmHg which decreased to 12.01 IOP mmHg, 12.57 mmHg and 12.90 mmHg at 4 weeks, 8 weeks and 12 weeks postoperatively, respectively (all p-values<0.0001. There was a correlation between lens thickness and changes of and ACD after the surgery. There was also a positive correlation between preoperative IOP and IOP reduction after the surgery. Conclusion: Phacoemulsification decreases IOP specially in eyes with higher preoperative IOP and thicker lenses.

  15. Acrylic purification and coatings

    CERN Document Server

    ,

    2012-01-01

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  16. Treatment of dystrophic calcification on a silicone intraocular lens with pars plana vitrectomy

    OpenAIRE

    Mehta N; Goldberg RA; Shah CP

    2014-01-01

    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 po...

  17. The Impact of Multifocal Intraocular Lens in Retinal Imaging with Optical Coherence Tomography

    OpenAIRE

    Dias-Santos, A; Costa, L; Lemos, V; Anjos, R.; Vicente, A.(IFPA, Dep. AGO, Université de Liège, Bat B5, Sart-Tilman, B-4000, Liège 1, Belgium); Ferreira, J; Cunha, JP

    2015-01-01

    Multifocal intraocular lenses (MF IOLs) have concentric optical zones with different dioptric power, enabling patients to have good visual acuity at multiple focal points. However, several optical limitations have been attributed to this particular design. The purpose of this study is to access the effect of MF IOLs design on the accuracy of retinal optical coherence tomography (OCT). Cross-sectional study conducted at the Refractive Surgery Department of Central Lisbon Hospital Center. Twent...

  18. 单眼角膜散光白内障患者不同人工晶状体组合植入的对比研究%Comparison of different combinations of intraocular lenses implantation in cataract patients with unilateral astigmatism

    Institute of Scientific and Technical Information of China (English)

    田芳; 张红; 胡尊霞

    2011-01-01

    Objective To assess binocular visual function after combined implantation of toric and multifocal or monofocal intraocular lenses in unilateral astigmatism cataract patients. Methods This was a prospective case control study. A total of thirty unilateral astigmatism patients undergoing phacoemulsification were recruited. AcrySof Toric IOL were implanted in the astigmatic eye of patients, with ReSTOR (15 eyes) or AcrySof IQ (15 eyes) in the contralateral eye. Six months postoperatively, patients were assessed for visual acuity (5.0 m, 60.0 cm, 40.0 cm), contrast sensitivity, amplitude of accommodation, and stereoacuity. Patients were surveyed for visual disturbances and lifestyle visual quality. Data were analyzed with a paired t test, an independent samples t test, or chi-square test. Results At 6 months postoperatively, for Toric-ReSTOR patients, uncorrected binocular logMAR visual acuity at 5.0 m, 60.0 cm, 40.0 cm was 0.05±0.05, 0.24±0.10, and 0.14±0.06, respectively. For Toric-AcrySof IQ patients, uncorrected binocular logMAR visual acuity was 0.06±0.07, 0.26±0.08, and 0.37 ±0.10, respectively. These values between the two group did not achieve significant differences except for near visual acuity (t=5.476, P=0.000). The contrast sensitivity for ReSTOR eyes was lower at 18 cpd under photopic and photopic glare circumstance than for the AcrySof IQ eyes (0.30 ± 0.37 versus 0.94 ±0.58, t=3.476, P=0.001; 0.34 ± 0.44 versus 0.88 ±0.52, t =2.975, P= 0.006). And was lower at 12 cpd under scotopic and scotopic glare circumstance than for the AcrySof IQ eyes (0.05±0.22 versus 0.50±0.61, t=3.057, P=0.005; 0.05±0.22 versus 0.59±0.75, t=3.154, P=0.004). The amplitude curve of accommodation in Toric-ReSTOR patients had two wave peak (0 and-2.5 D), but only one (0 D) in Toric-AcrySof IQ patients. The stereopsis of Toric-ReSTOR eyes decreased slightly (53% versus 73%, x2=1.262, P=0.263). Patient satisfaction for mean near vision was significantly different: 80

  19. Surgical management of intraocular lens dislocations

    Directory of Open Access Journals (Sweden)

    Adem Gul

    2015-10-01

    Full Text Available ABSTRACTPurpose:To report and compare the surgical, visual, and anatomical outcomes following treatment of dislocated intraocular lenses (IOLs.Methods:The medical records of 28 eyes of 28 patients were evaluated. Age, gender, pre-and postoperative best-corrected visual acuity (BCVA, surgical methods, and complications were recorded.Results:Pre-and postoperative BCVA ranged from counting fingers to 20/32 and from counting fingers to 20/25, respectively. Late-onset dislocations were the most frequently observed complication. The most frequent surgical method was IOL repositioning in 15 of 28 patients, followed by IOL exchange in 11 patients, and IOL removal in 2 patients. Only 1 patient required surgical re-intervention with IOL capture.Conclusions:Visual acuity improved following the use of either IOL repositioning or IOL exchange. No superiority of one method over the other was observed. In the present retrospective case series, management of dislocated IOLs with repositioning or exchange of the primary implant conferred comparable surgical and visual outcomes.

  20. Hyperbranched urethane-acrylates

    Directory of Open Access Journals (Sweden)

    Tasić Srba

    2004-01-01

    Full Text Available The synthesis, characterization and UV-curing of hyperbranched urethaneacrylates (HB-UA were investigated in this study. They were evaluated as oli-gomers in model UV curable coatings. HB-UAs were synthesized by reaction of an aliphatic hyperbranched polyester of the second generation (HBRG2 and an isocyanate adduct, obtained by the reaction of isophoronediisocyana-te and different hydroxy alkyl acrylates. Their thermal properties and viscosities depend on the degree of modification of HBRG2 and the type of hydroxy alkyl acrylate used. The introduction of a flexible alkoxylated spacer between the HBP core and acrylate end groups reduces steric hindrance by moving the cross linkable acrylate groups away from the HBP core and increase its reactivity. Due to the presence of abstractable H-atoms in the α-position to the ether links, HB-UAs based on poly(ethylene oxide monoacrylate are very reactive and do not show oxygen inhibition. The obtained coatings combine a high cross linking density with flexible segments between the cross links, which results in a good compromise between hardness and flexibility and have the potential to be used in different UV-curing applications.

  1. 21 CFR 886.3600 - Intraocular lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens. 886.3600 Section 886.3600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials...

  2. Gravitational Lensing in Astronomy

    CERN Document Server

    Wambsganss, J

    1998-01-01

    Deflection of light by gravity was predicted by General Relativity and observationaly confirmed in 1919. In the following decades various aspects of the gravitational lens effect were explored theoretically, among them the possibility of multiple or ring-like images of background sources, the use of lensing as a gravitational telescope on very faint and distant objects, and the possibility to determine Hubble's constant with lensing. Only relatively recently gravitational lensing became an observational science after the discovery of the first doubly imaged quasar in 1979. Today lensing is a booming part of astrophysics. In addition to multiply-imaged quasars, a number of other aspects of lensing have been discovered since, e.g. giant luminous arcs, quasar microlensing, Einstein rings, galactic microlensing events, arclets, or weak gravitational lensing. By now literally hundreds of individual gravitational lens phenomena are known. Although still in its childhood, lensing has established itself as a very use...

  3. Specific features of measuring the optical power of artificial refractive and diffractive-refractive eye lenses

    Science.gov (United States)

    Lenkova, G. A.

    2016-08-01

    Methods for monitoring the optical power of artificial refractive eye lenses (intraocular lenses) based on measuring focal lengths in air and in medium are analyzed. The methods for determining the refraction of diffractive-refractive lenses (in particular, of MIOL-Akkord type), with allowance for the specific features of the diffractive structure, are considered. A computer simulation of the measurement of the focal length of MIOL-Akkord lenses is performed. The effective optical power of the diffractive component of these lenses is shown to depend on the diaphragm diameter. The optimal diaphragm diameter, at which spherical aberrations do not affect the position of foci, is found to be 3 mm. Possible errors in measuring the focal lengths are analyzed, and the necessary corrections that must be introduced into measurement results and calculations of refractions are determined.

  4. Study on Titanium Nitride Film Modified for Intraocular Lens

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective:To study the characteristics of the intraocular lens using ion beam sputtering depositing titanium nitride thin film on the intraocular lens(IOLs).Methods:To deposite titanium nitride thin film on the top of intraocular lens by ion beam sputtering depositing.We analyzed the surface morphology of intraocular lens through SEM and AFM.We detected intraocular lens resolution through the measurement of intraocular lens.Biocompatibility of intraocular lens is preliminary evaluated in this test.Results:T...

  5. 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

    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 twelve patients, 4) subluxation of the IOL was observed in one patient, and 5) macular edema was found in three eyes. Conclusion 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

  6. 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

  7. Comparison study of visual function and patient satisfaction in patients with monovision and patients with bilateral multifocal intraocular lenses%双眼植入多焦点人工晶状体与单眼视设计术后视功能及满意度的比较

    Institute of Scientific and Technical Information of China (English)

    穆晶; 陈晖; 李一壮

    2014-01-01

    multifocal intraocular lenses (IOL) and patients with monofocal IOL monovision.Methods Prospective nonrandomized controlled study.This study comprised consecutive bilateral cataract patients 45 cases(90eyes) between January 2011 and March 2012.All cases were divided into two groups:multifocal IOL group(23 patients) having implantation of AcrySof ReSTOR +3D(SN6AD1) multifocal IOL,monovision group(22 patients) having implantation of AcrySof IQ (SN60WF) IOL.Parameters analyzed 3 months postoperatively included binocular uncorrected distance,intermediate,and near visual acuities; stereo vision;photopic and mesopic contrast sensitivity function without glare.Parameters analyzed 6 months postoperatively included spectacle independence; subjective visual symptoms; and patient satisfaction.The independent-samples t test were used to compare the measure data which met normal distribution.The chisquare test was applied to compare categorical variables.Results There were no significant differences between groups in bilateral uncorrected distance vision(0.13 ±0.06,0.17 ±0.19;Z =1.755,P =0.086),intermediate(0.34-0.05,0.33 ±0.06;Z =-0.821,P =0.416),and near vision (0.35 ±0.06,0.41 ± 0.09 ;Z =2.117,P =0.051).There were significant differences between groups in stereo vision (Median:150",525" ;Z =-2.092,P =0.036).Percentage of patients wearing spectacle were less than 10% in all groups [91.3% (21/23),90.9% (20/22)].On the questionnaire,patients in multifocal IOL group complained with double vision,trouble in night vision and halo(21.7%).Conclusions Pseudophakic monovision and MIOL achieved distance vision,intermediate vision and near vision.But monovision was no risk for disturbing visual symptoms associated with multifocal IOL.

  8. 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

    OpenAIRE

    Navarro, Rodrigo M.; Machado, Leonardo M.; Ossires Maia; Lihteh Wu; Farah, Michel E.; Octaviano Magalhaes; J Fernando Arevalo; Mauricio Maia

    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, biomicro...

  9. 23-gauge Transconjunctival Sutureless Vitrectomy in Eyes with Posteriorly Dislocated Intraocular Lens after Cataract Surgery

    Directory of Open Access Journals (Sweden)

    Fatih Horozo¤lu

    2011-08-01

    Full Text Available Purpose: To evaluate the outcomes of 23-gauge (23-G transconjunctival sutureless vitrectomy (TSV in eyes with posteriorly dislocated intraocular lens (IOL after cataract surgery. Material and Method: In this retrospective study, we evaluated 6 eyes of 6 consecutive cases with posteriorly dislocated intraocular lens after cataract surgery between April 2007 and November 2010. Visual acuity, intraocular pressure, detailed fundus examination and details of surgery were recorded. Results: The mean age of the patients was 64.7 years and the mean follow-up was 5.5 months (3-12 months. All eyes received 23-G TSV. Dislocated IOL was removed from the vitreous and implanted into ciliary sulcus in 2 eyes (33.3% with polymethylmetacrilate IOL and in 4 eyes (66.7% with 3-piece hydrophilic acrylic IOL. In 5 of the 6 eyes (83.7%, visual acuity improved postoperatively. In one eye (16.7%, elevation of intraocular pressure was observed postoperatively and controlled by topical treatment. Discussion: 23-G TSV surgery may be used in eyes with posteriorly IOLs after cataract surgery. Studies with a larger number of patients would better demonstrate the efficacy of this method. (Turk J Ophthalmol 2011; 41: 213-6

  10. 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.

  11. 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…

  12. [Intraocular Inflammation: Autoimmune or Infectious?].

    Science.gov (United States)

    Auw-Hädrich, C; Heinzelmann, S; Coupland, S

    2016-07-01

    Presentation of 3 cases of intraocular inflammation: 1. 47-year old female patient with severe necrotising scleritis and uveitis with underlying granulomatous polyangiitis (formerly known as Wegener granulomatosis, in honour of the German pathologist Friedrich Wegener), known for 10 years. 2. 48-year old male patient with longstanding bilateral uveitis and granulomatous polyangiitis for 2 years. In the histopathological examination of the enucleation specimen, a retrolental tumour turned out to be a granuloma. 3. 57-year old male patient in status post renal transplantation with intraocular cellular infiltration suspicious for lymphoma, which surprisingly proved to be Toxoplasma gondii-associated uveitis. The clinical course and characteristic histological signs and therapeutic options are discussed. PMID:27468098

  13. The Orphan Lenses Project

    Science.gov (United States)

    Moustakas, Leonidas A.; Brownstein, J.; Fadely, R.; Fassnacht, C. D.; Gavazzi, R.; Goodsall, T.; Griffith, R. L.; Keeton, C. R.; Kneib, J. P.; Koekemoer, A.; Koopmans, L. V. E.; Marshall, P. J.; Merten, J.; Metcalf, R. B.; Oguri, M.; Papovich, C.; Rein, H.; Ryan, R.; Stewart, K. R.; Treu, T.

    2012-01-01

    Strong gravitational lenses are uniquely suited for the study of dark matter structure and substructure within massive halos of many scales, act as gravitational telescopes for distant faint objects, and can give powerful and competitive cosmological constraints. Some 300 lenses have been identified in the literature in one form or another; many others have been found, but perhaps have not warranted dedicated publications. The Orphan Lenses project aims to be a master compilation of all strong gravitational lenses that are known, and a community repository for candidate lenses. A clear and uniform database of basic properties and gravitational lens models is being developed, which will be available online and through a smartphone interactive application. I will present the project, and scientific highlights with this dataset.

  14. Cosmology with Gravitational Lensing

    CERN Document Server

    Heavens, Alan

    2011-01-01

    In these lectures I give an overview of gravitational lensing, concentrating on theoretical aspects, including derivations of some of the important results. Topics covered include the determination of surface mass densities of intervening lenses, as well as the statistical analysis of distortions of galaxy images by general inhomogeneities (cosmic shear), both in 2D projection on the sky, and in 3D where source distance information is available. 3D mass reconstruction and the shear ratio test are also considered, and the sensitivity of observables to Dark Energy is used to show how its equation of state may be determined using weak lensing. Finally, the article considers the prospect of testing Einstein's General Relativity with weak lensing, exploiting the differences in growth rates of perturbations in different models.} \\abstract{In these lectures I give an overview of gravitational lensing, concentrating on theoretical aspects, including derivations of some of the important results. Topics covered include...

  15. [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

  16. Acrylic Acid and Esters Will Be Oversupply

    Institute of Scientific and Technical Information of China (English)

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  17. 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...

  18. Intraocular lens with accommodation capacity

    OpenAIRE

    Dorronsoro, Carlos; Alejandre, Nicolás; Bekesi, Nandor; Marcos, Susana

    2014-01-01

    Intraocular lens with accommodation capacity comprising a first optical member (1) having a dynamic optical power, to which a second optical member (2) with a fixed optical power is affixed, in such a manner that at least a central part of each of one of one of the curved surfaces (2a, 2b) of the second optical member (2) and of at least one of the surfaces (1a, 1b) of the first optical member (1) are in contact with each other, the second optical member (2) and the first optical member (1) p...

  19. Pars plana cicatrization of sewn-in posterior chamber intraocular lens haptics.

    Science.gov (United States)

    McDermott, M L; Puklin, J E

    1997-03-01

    The authors describe the unexpected finding of cicatrization of posterior chamber lens haptics to the pars plana. This was found during removal of a secondary, transscleral sewn-in pseudophakos during a retinal reattachment procedure. Ophthalmic history and intraoperative photography revealed pars plana cicatrization of haptics. Despite removal of trans-scleral prolene fixation sutures and application of gentle traction, the posterior chamber lens haptics remained firmly adherent to pars plana retina. The haptics were amputated to prevent significant chorioretinal damage. The conventional belief that all sewn-in posterior chamber intraocular lenses cause little or no scarring response around the haptics may be unfounded.

  20. Experimentally observe the effect of spherical aberration on diffractive intraocular lens using adaptive optics

    Science.gov (United States)

    Guo, Huanqing; DeLestrange, Elie

    2015-03-01

    We first investigated the similarity in optical quality of a batch of diffractive intraocular lenses (DIOLs), providing experimental evidence for one DIOL as representative of a batch. Using adaptive optics, we then evaluated one DIOL under different levels of Zernike spherical aberration (SA) by applying both a point spread function test and a psychophysical visual acuity test. We found that for small aperture size SA has the effect of shifting the through-focus curve of DIOL. Also, for a relatively large aperture size, it has different effects on the distant and near foci.

  1. Biocompatibility of intraocular lens materials%人工晶体材料的生物相容性特征★

    Institute of Scientific and Technical Information of China (English)

    王洋; 韩宏光

    2013-01-01

      BACKGROUND: The visual recovery and complications of the cataract patients are various after different intraocular lens materials implantation, so the selection of appropriate intraocular lens materials is the key of the research. OBJECTIVE: To investigate the properties and biocompatibility of intraocular lens materials. METHODS: The materials were classified according to the hardness and location of the intraocular lens after implantation in order to analyze the pros and cons of the intraocular lens thus guiding the patients to select the appropriate intraocular lens for implantation. The properties and biocompatibility of the commonly used intraocular lens materials were evaluated. RESUTLS AND CONCLUSION: Polymethylmethacrylate intraocular lens is the first choice of rigid material, but it cannot tolerate autoclaving. Acrylic intraocular lens is the soft and foldable intraocular lens that has the similar optical and biological properties with polymethylmethacrylate intraocular lens, and it can improve the visual acuity after implantation with less complications. Posterior capsular opacification is the most important indicator for biocompatibility evaluation which is related with the material and design of intraocular lens. The stability of intraocular lens in the capsular bag is also the indicator to evaluate the biocompatibility. The material properties, biocompatibility, and visual function should be taking into consideration in the design and selection of intraocular lens materials. Guarantee the efficacy after intraocular lens implantation and reduce the incidence of complications, so that to get vision rehabilitation for the cataract patients.%  背景:白内障患者植入不同材料人工晶体治疗后的视力恢复情况和并发症有所不同,选择适宜的人工晶体材料是研究的关键。目的:探讨人工晶体材料的特征和生物相容性。方法:按人工晶体的硬度和植入后不同位置将材料进行分类

  2. Weak Gravitational Lensing

    Science.gov (United States)

    Pires, Sandrine; Starck, Jean-Luc; Leonard, Adrienne; Réfrégier, Alexandre

    2012-03-01

    This chapter reviews the data mining methods recently developed to solve standard data problems in weak gravitational lensing. We detail the different steps of the weak lensing data analysis along with the different techniques dedicated to these applications. An overview of the different techniques currently used will be given along with future prospects. Until about 30 years ago, astronomers thought that the Universe was composed almost entirely of ordinary matter: protons, neutrons, electrons, and atoms. The field of weak lensing has been motivated by the observations made in the last decades showing that visible matter represents only about 4-5% of the Universe (see Figure 14.1). Currently, the majority of the Universe is thought to be dark, that is, does not emit electromagnetic radiation. The Universe is thought to be mostly composed of an invisible, pressure less matter - potentially relic from higher energy theories - called "dark matter" (20-21%) and by an even more mysterious term, described in Einstein equations as a vacuum energy density, called "dark energy" (70%). This "dark" Universe is not well described or even understood; its presence is inferred indirectly from its gravitational effects, both on the motions of astronomical objects and on light propagation. So this point could be the next breakthrough in cosmology. Today's cosmology is based on a cosmological model that contains various parameters that need to be determined precisely, such as the matter density parameter Omega_m or the dark energy density parameter Omega_lambda. Weak gravitational lensing is believed to be the most promising tool to understand the nature of dark matter and to constrain the cosmological parameters used to describe the Universe because it provides a method to directly map the distribution of dark matter (see [1,6,60,63,70]). From this dark matter distribution, the nature of dark matter can be better understood and better constraints can be placed on dark energy

  3. Toric intraocular lens orientation and residual refractive astigmatism: an analysis

    Directory of Open Access Journals (Sweden)

    Potvin R

    2016-09-01

    Full Text Available Rick Potvin,1 Brent A Kramer,2 David R Hardten,3 John P Berdahl4 1Science in Vision, Akron, NY, 2University of Iowa Carver College of Medicine, Iowa City, IA, 3Minnesota Eye Consultants, Minnetonka, MN, 4Vance Thompson Vision, Sioux Falls, SD, USA Purpose: To analyze intraocular lens (IOL orientation data from an online toric back-calculator (astigmatismfix.com for determining if differences were apparent by lens type.Methods: A retrospective review of astigmatismfix.com toric back-calculations that included IOL identification and intended orientation axis.Results: Of 12,812 total validated calculation records, 8,229 included intended orientation and lens identification data. Of the latter, 5,674 calculations (69% involved lenses oriented 5° or more from their intended position. Using estimated toric lens usage data, the percentage of lenses with orientation ≥5° from intended was 0.89% overall, but the percentage varied significantly between specific toric lens brands (P<0.05. The percentage of back-calculations related to lenses that were not oriented as intended was also statistically significantly different by lens brand (P<0.05. When IOLs were misoriented, they were significantly more likely to be misoriented in a counterclockwise direction (P<0.05. This was found to be due to a bias toward counterclockwise orientation observed with one specific brand, a bias that was not observed with the other three brands analyzed here.Conclusion: The percentage of eyes with lens orientation ≥5° from intended in the Toric Results Analyzer data set was <1% of toric IOLs in general, with the relative percentage of Tecnis® Toric IOLs significantly higher than AcrySof® Toric IOLs. Both of these had higher rates than the Staar® Toric and Trulign® Toric lenses, with the availability of higher Tecnis and AcrySof cylinder powers a likely contributing factor. The AcrySof Toric IOL appears to be less likely than the Tecnis Toric IOL to cause residual

  4. 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

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

    Science.gov (United States)

    Alba-Bueno, Francisco; Vega, Fidel; Millán, María S.

    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

  6. Cytomegalovirus retinitis mimicking intraocular lymphoma

    Directory of Open Access Journals (Sweden)

    Patrick Gooi

    2008-12-01

    Full Text Available Patrick Gooi1, James Farmer2, Bernard Hurley3, Elliott Brodbaker41Department of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; 2Department of Pathology and Lab Medicine University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; 3Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada; 4Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CanadaAbstract: We present a case of an unusual retinal infiltrate requiring retinal biopsy for definitive diagnosis. A 62-year-old man with treated lymphoma presented with decreased vision in the right eye associated with a white retinal lesion, which extended inferonasally from an edematous disc. Intraocular lymphoma was considered as a diagnosis; thus, the patient was managed with vitrectomy and retinal biopsy. Cytological analysis of the vitreous aspirate could not rule out a lymphoproliferative disorder. The microbial analysis was negative. Histology of the lesion showed extensive necrosis and large cells with prominent nucleoli. To rule out lymphoma, a battery of immunostains was performed and all were negative. However the limited amount of tissue was exhausted in the process. Subsequently, a hematoxylin and eosin (H/E slide was destained, on which a CMV immunostain was performed. This revealed positivity in the nuclei and intranuclear inclusions within the large atypical cells. A diagnosis of CMV retinitis was made. Retinal biopsy may provide a definitive diagnosis and direct patient care toward intravenous gancyclovir in the case of CMV or toward radiation and chemotherapy for intraocular lymphoma. When faced with a limited amount of tissue, destaining regular H/E slides is a possible avenue to performing additional immunohistochemical studies.Keywords: CMV retinitis, retinal biopsy, immunohistochemistry, destaining

  7. Gravitational Lensing & Stellar Dynamics

    CERN Document Server

    Koopmans, L V E

    2005-01-01

    Strong gravitational lensing and stellar dynamics provide two complementary and orthogonal constraints on the density profiles of galaxies. Based on spherically symmetric, scale-free, mass models, it is shown that the combination of both techniques is powerful in breaking the mass-sheet and mass-anisotropy degeneracies. Second, observational results are presented from the Lenses Structure & Dynamics (LSD) Survey and the Sloan Lens ACS (SLACS) Survey collaborations to illustrate this new methodology in constraining the dark and stellar density profiles, and mass structure, of early-type galaxies to redshifts of unity.

  8. 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.

  9. Weak and Strong Lensing Statistics

    OpenAIRE

    Straumann, Norbert

    2001-01-01

    After a brief introduction to gravitational lensing theory, a rough overview of the types of gravitational lensing statistics that have been performed so far will be given. I shall then concentrate on recent results of galaxy-galaxy lensing, which indicate that galactic halos extend much further than can be probed via rotation of stars and gas.

  10. Clinical study of customized aspherical intraocular lens implants

    Institute of Scientific and Technical Information of China (English)

    Lie-Xi; Jia; Zhao-Hui; Li

    2014-01-01

    AIM:To compare if there is an improvement in visual functions with age-related cataracts between patients receiving a aspherical intraocular lens(IOL) based on corneal wavefront aberration and patients randomly assigned lenses.METHODS:A total of 124 eyes of 124 patients with age-related cataracts were placed in experimental group and a group receiving randomly assigned(RA) lenses.The experimental group was undergone Pentacam corneal spherical aberration measurement before surgery; the targeted range for residual total spherical aberration after surgery was set to 0-0.3 μm. Patients with a corneal spherical aberration <0.3 μm were implanted with a zero-spherical aberration advanced optics(AO) aspherical IOL and patients with an aberration ≥0.3 μm received a Tecnis Z9003 aspherical lens in experimental group. RA patients were randomly implanted with an AO lens or a Tecnis Z9003 lens. Three months after surgery total spherical aberration, photopic/mesopic contrast sensitivities, photopic/mesopic with glare contrast sensitivities, and logMAR vision were measured.RESULTS:Statistical analysis on logMAR vision showed no significant difference between two groups(P =0.413). The post-surgical total spherical aberration was 0.126 ±0.097 μm and 0.152 ±0.151 μm in the experimental and RA groups, respectively(P =0.12). The mesopic contrast sensitivities at spatial frequencies of 6,12 and 18 c/d in the experimental group were significantly higher than of the RA group(P =0.00; P =0.04;P =0.02). The mesopic with glare contrast sensitivity in the experimental group at a spatial frequency of 18 c/d was also significantly higher vs the RA group(P =0.01).CONCLUSION:Pre-surgical corneal spherical aberration measurement in cataract patients followed bycustomized selection of aspherical IOL implants improved mesopic contrast sensitivities at high spatial frequencies, and thus is a superior strategy compared to the random selection of aspherical intraocular lens implants.

  11. Reverse Optic Capture to Stabilize a Toric Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Howard V. Gimbel

    2013-09-01

    Full Text Available Purpose: To describe a technique for stabilizing a rotationally unstable toric intraocular lens (IOL. Method: Case report and literature review. Results: Surgical technique and long-term follow-up for a patient who underwent repositioning and stabilization of a mobile 1-piece acrylic toric IOL using reverse optic capture (ROC are described. This patient presented with early, more than 70° off-axis rotation. The IOL was repositioned but was very mobile within the bag and tended to rotate off-axis; hence, it was stabilized in the desired position by capturing the optic through the anterior continuous curvilinear capsulorhexis, leaving the haptics in the bag. The immediate and 2-year postoperative follow-up revealed a stable and on-axis IOL with no visual, refractive or ocular complications. Conclusions: ROC is a useful and safe technique to address the problem of toric IOLs that tend to rotate at the time of surgery or are not stable postoperatively.

  12. Intraocular cilia associated with perforating injury

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    2000-01-01

    Full Text Available Purpose: To report a case series of penetrating injury complicated by occurrence of intraocular cilia. Methods: Retrospective analysis of charts of 11 eyes of 11 patients with penetrating injury and intraocular cilia, presenting between September 1978 and November 1998. Ten eyes underwent surgery for trauma-related problems such as cataract, vitritis, retinal detachment etc., at which time intraocular cilia were removed. One eye did not have surgery and continues to harbour cilia at the posterior perforation site. Results: Metallic wire was responsible for injury in 6 of 11 eyes with intraocular cilia. Five eyes had significant intraocular inflammation. The cilia were located in the anterior segment in 4 eyes; in the posterior segment in 6 eyes and in both in one eye. At the last follow up, 72.7% had 6/18 or better vision. Poor vision in the rest was due to recurrent retinal detachment (2 eyes and macular scarring (1 eye. Conclusion: Intraocular cilia are more commonly associated with injury by a metallic wire. The presentation and management of an injured eye does not seem to be influenced by the presence of cilia in the eye.

  13. [Results of intraocular lens implantation in cataract complicated by medium and high myopia].

    Science.gov (United States)

    Plotnikova, Iu A; Chuprov, A D; Volkov, D V

    2001-01-01

    Results of surgical treatment of cataract complicated by medium and high myopia are analyzed. The main group consisted of 90 patients (96 eyes) subjected to extracapsular cataract extraction with implantation of posterior-chamber intraocular lenses and the reference group of 128 patients in whom cataract was extracted without implantation of artificial lens. The study included creation of a mathematical model of myopic eye with estimation of pressure fluctuations in various zones of the eye, developing during transposition of the vitreous during patient's movements (head movements, jumps, falling) and the damping effect of the lens in the ocular system. It was proven by mathematical calculations that transpositions of jelly fractions of the vitreous decreased by 70% in an eye with the lens in comparison with their transposition in aphakia. Clinical studies demonstrated the efficiency of intraocular correction of aphakia in high myopia: implantation of an intraocular lens decreases the risk of detachment of the retina during the postoperative period and helps attain the desired refraction. PMID:11765458

  14. Gold Nanoslit Lenses

    OpenAIRE

    Ishii, Satoshi; Kildishev, Alexander V.; Shalaev, Vladimir M.; Chen, Kuo-Ping; Drachev, Vladimir P.

    2011-01-01

    We experimentally demonstrate the focusing properties of arrays of parallel subwavelength-wide nanoslits in a gold film. The lenses are designed to focus either TM- or TE-polarized light and diverge the light of the orthogonal polarization. (C) 2010 Optical Society of America

  15. Primary Posterior Chamber Intraocular Lens Implantation in Traumatic Cataract With Posterior Capsule Breaks

    Institute of Scientific and Technical Information of China (English)

    YupingZou; WenhuiYang

    1995-01-01

    Background:In patients with incomplete posterior capsule support,posterior chamber intraocular lenses(PC-IOLs)were implanted with both haptics transs-cleral fixation.This causes more damage to the eye and may result in more com-plications,In patients with small posterior breaks,non-fixation or single haptic fixation may be adequate.Methods:Thiry-two consecutive patients of traumatic cataract with posterior capsule breaks caused by penetrating eye trauma were retospected.Posterior chamber intraocular lenses were implanted in all these patients with three tech-niques,ie,without fixation,with single haptic fixation and with both haptics fixation .The selection of the technique was based on the position and size of the posterior capsule.The follow-up period was 21days to 28months(mean,15.2months).Results:Intra-operative problems included ciliary body bleeding(Two patents,6.25%)and enlargement of posterior capsule breaks(2patients,6.25).Postoperative visual acuity was0.5or better(Corrected)in28case(87.5%)and 0.1-0.4in four patients(12.5%),Postoperative complications included hyphema(6eyes,18.8%),transient intraocular pressure elevation(6eyes,18.8%),transient hypotention(7eyes,21.8%).Postoperative IOL position were good except one case of IOL tilt.No pupillary capture or endophthalmitis was found.Conclusions:Not all PC-IOLs have to be fixed by two haptics.In patients with small posterior capsule breaks,PC-IOLmay not be fixed or fixed by only one haptics.Eye Science1995;11:140-142.

  16. Phakic anterior chamber intraocular lens (Verisyse™) implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

    OpenAIRE

    Pirouzian, Amir; Ip, Kenneth C; O’Halloran, Henry S

    2009-01-01

    Purpose: The current study aims to evaluate both safety and efficacy of Verisyse™ (AMO, Irvine, CA) phakic anterior chamber intraocular lens (IOL) in the reduction of clinically significant (>−8 D) myopic anisometropia in children who are noncompliant to traditional medical treatment including spectacle correction or contact lenses. Design: Retrospective interventional case series. Methods: Six anisometropic myopic pediatric patients in one practice were identified through chart-review. None ...

  17. Posterior capsular opacification: Incidence and factors influencing and rate of Nd:YAG capsulotomy in diabetic and uveitic patients and after multifocal intraocular lens implantation.

    OpenAIRE

    Elgohary, M A

    2005-01-01

    This thesis examined the incidence and factors affecting the rate of posterior capsular opacification (PCX)), the most common complication of cataract surgery, in diabetic and uvcitic patients and in patients with multifocal intraocular lenses (IOLs). These patients arc particularly sensitive to PCO development because of the risks associated with Nd:YAG capsulotomy in the former two groups and the potential effect on visual function in the latter group. PCO rate was estimated both retrospect...

  18. SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

    Institute of Scientific and Technical Information of China (English)

    Li Jia; Zong-hui Liu; De-qing Wei

    2002-01-01

    Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-freepolymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reactioncondition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in thehydrosols is 2%. The maximum weight average molecular weight (Mw) of polymer that assures soap-free emulsionconversion into hydrosol is about 1.2 × 105-1.3 × 105. The particle transforming process was investigated, and an obviouschange of particle diameter and morphology was observed.

  19. Learning unit: Thin lenses

    Science.gov (United States)

    Nita, L.-S.

    2012-04-01

    Learning unit: Thin lenses "Why objects seen through lenses are sometimes upright and sometimes reversed" Nita Laura Simona National College of Arts and Crafts "Constantin Brancusi", Craiova, Romania 1. GEOMETRIC OPTICS. 13 hours Introduction (models, axioms, principles, conventions) 1. Thin lenses (Types of lenses. Defining elements. Path of light rays through lenses. Image formation. Required physical quantities. Lens formulas). 2. Lens systems (Non-collated lenses. Focalless systems). 3. Human eye (Functioning as an optical system. Sight defects and their corrections). 4. Optical instruments (Characteristics exemplified by a magnifying glass. Paths of light rays through a simplified photo camera. Path of light rays through a classical microscope) (Physics curriculum for the IXth grade/ 2011). This scenario exposes a learning unit based on experimental sequences (defining specific competencies), as a succession of lessons started by noticing a problem whose solution assumes the setup of an experiment under laboratory conditions. Progressive learning of theme objectives are realised with sequential experimental steps. The central cognitive process is the induction or the generalization (development of new knowledge based on observation of examples or counterexamples of the concept to be learnt). Pupil interest in theme objectives is triggered by problem-situations, for example: "In order to better see small objects I need a magnifying glass. But when using a magnifier, small object images are sometimes seen upright and sometimes seen reversed!" Along the way, pupils' reasoning will converge to the idea: "The image of an object through a lens depends on the relative distances among object, lens, and observer". Associated learning model: EXPERIMENT Specific competencies: derived from the experiment model, in agreement with the following learning unit steps I. Evoking - Anticipation: Size of the problem, formulation of hypotheses and planning of experiment. II

  20. Biopsy techniques for intraocular tumors

    Directory of Open Access Journals (Sweden)

    Pukhraj Rishi

    2016-01-01

    Full Text Available Biopsy involves the surgical removal of a tissue specimen for histopathologic evaluation. Most intraocular tumors are reliably diagnosed based on the clinical evaluation or with noninvasive diagnostic techniques. However, accurately diagnosing a small percentage of tumors can be challenging. A tissue biopsy is thus needed to establish a definitive diagnosis and plan the requisite treatment. From fine-needle aspiration biopsy (FNAB to surgical excision, all tissue collection techniques have been studied in the literature. Each technique has its indications and limitations. FNAB has been reported to provide for 88-95% reliable and safe ophthalmic tumor diagnosis and has gained popularity for prognostic purposes and providing eye conserving treatment surgeries. The technique and instrumentation for biopsy vary depending upon the tissue involved (retina, choroid, subretinal space, vitreous, and aqueous, suspected diagnosis, size, location, associated retinal detachment, and clarity of the media. The cytopathologist confers a very important role in diagnosis and their assistance plays a key role in managing and planning the treatment for malignancies.

  1. Biopsy techniques for intraocular tumors.

    Science.gov (United States)

    Rishi, Pukhraj; Dhami, Abhinav; Biswas, Jyotirmay

    2016-06-01

    Biopsy involves the surgical removal of a tissue specimen for histopathologic evaluation. Most intraocular tumors are reliably diagnosed based on the clinical evaluation or with noninvasive diagnostic techniques. However, accurately diagnosing a small percentage of tumors can be challenging. A tissue biopsy is thus needed to establish a definitive diagnosis and plan the requisite treatment. From fine-needle aspiration biopsy (FNAB) to surgical excision, all tissue collection techniques have been studied in the literature. Each technique has its indications and limitations. FNAB has been reported to provide for 88-95% reliable and safe ophthalmic tumor diagnosis and has gained popularity for prognostic purposes and providing eye conserving treatment surgeries. The technique and instrumentation for biopsy vary depending upon the tissue involved (retina, choroid, subretinal space, vitreous, and aqueous), suspected diagnosis, size, location, associated retinal detachment, and clarity of the media. The cytopathologist confers a very important role in diagnosis and their assistance plays a key role in managing and planning the treatment for malignancies. PMID:27488148

  2. Pulsar lensing geometry

    CERN Document Server

    Liu, Siqi; Macquart, J-P; Brisken, Walter; Deller, Adam

    2015-01-01

    Our analysis of archival VLBI data of PSR 0834+06 revealed that its scintillation properties can be precisely modelled using the inclined sheet model (Pen & Levin 2014), resulting in two distinct lens planes. These data strongly favour the grazing sheet model over turbulence as the primary source of pulsar scattering. This model can reproduce the parameters of the observed diffractive scintillation with an accuracy at the percent level. Comparison with new VLBI proper motion results in a direct measure of the ionized ISM screen transverse velocity. The results are consistent with ISM velocities local to the PSR 0834+06 sight-line (through the Galaxy). The simple 1D structure of the lenses opens up the possibility of using interstellar lenses as precision probes for pulsar lens mapping, precision transverse motions in the ISM, and new opportunities for removing scattering to improve pulsar timing. We describe the parameters and observables of this double screen system. While relative screen distances can i...

  3. Gravitational lensing by wormholes

    OpenAIRE

    Dey, Tushar Kanti; Sen, Surajit

    2008-01-01

    We have investigated the gravitational lensing by two wormholes, viz., Janis-Newman-Winnicour (JNW) wormhole and Ellis wormhole. The deflection angle in the strong field limit is calculated and various lens parameters of two wormholes are compared. It is shown that the JNW wormhole exhibits the relativistic images, while the Ellis wormhole does not have any relativistic images due to the absence of its photon sphere.

  4. Evaluation of visual acuity under different contrasts and luminances in eyes implanted with aspheric multifocal intraocular lenses%非球面多焦点人工晶状体植入眼不同背景亮度及不同对比度视功能观察

    Institute of Scientific and Technical Information of China (English)

    赵银莹; 李军花; 常平骏; 赵云娥

    2010-01-01

    目的 分析非球面多焦点人工晶状体(MIOL)[ReSTOR MIOL(SN6AD3)]植入眼在不同背景亮度不同对比度下的视功能.方法 采用前瞻性研究.2009年2月至2009年7月行白内障超声乳化吸除并植入SN6AD3且随访资料完整的病例26例(42眼),术后6个月在最佳远矫正状态下,采用多功能电子视力测量仪(MFVA-100)测试不同背景亮度(250、85、25 cd/m2)下不同对比度(100%、25%、10%、5%)视标的LogMAR视力.采用Dunnett's T3多重比较法对所得视力进行统计分析.结果 在250 cd/m2背景亮度下,不同对比度(100%、25%、10%、5%)视力平均值分别为0.01、0.23、0.40、0.62;85 cd/m2背景亮度下为0.02、0.26、0.46、0.74;25 cd/m2背景亮度下为0.08、0.32、0.49、0.63;在这3种背景亮度下,视力随着对比度下降而下降,差异有统计学意义(P均<0.05).同一对比度视标,不同背景亮度(250、85、25 cd/m2)下的视力采用Dunnett's T3多重比较法分析,结果示差异无统计学意义(P均>0.05).结论 植入非球面ReSTOR MIOL(SN6AD3)患者无论在高亮(250 cd/m2)、标准(85 cd/m2)、中间(25 cd/m2)背景亮度下均可获得满意的视力.视标的对比度对视力的影响较背景亮度更大.%Objective To evaluate the differences in contrast visual acuity (VA) under different background illuminations in patients who had been implanted with the ReSTOR aspheric multifocal intraocular lens (MIOL)(SN6AD3). Methods This was a prospective study. Forty-two eyes of 26 patients who had received ReSTOR MIOL (SN6AD3) implantation after cataract extraction were enrolled. Six months postoperatively, best corrected distance VA was measured at 4 contrast levels (100%, 25%, 10%, 5%) under 3 background illumination levels (250 cd/m2, 85 cd/m2, 25 cd/m2)using a multi-functional visual acuity tester (MFVA-100). Dunnett's T3 multiple comparison was used for statistical anaylysis. Results The mean VA at the 4 contrast levels (100%, 25%, 10%, 5%)under 250 cd

  5. Noiseless Gravitational Lensing Simulations

    CERN Document Server

    Angulo, Raul E; Hilbert, Stefan; Abel, Tom

    2013-01-01

    The microphysical properties of the DM particle can, in principle, be constrained by the properties and abundance of substructures in DM halos, as measured through strong gravitational lensing. Unfortunately, there is a lack of accurate theoretical predictions for the lensing signal of substructures, mainly because of the discreteness noise inherent to N-body simulations. Here we present Recursive-TCM, a method that is able to provide lensing predictions with an arbitrarily low discreteness noise, without any free parameters or smoothing scale. This solution is based on a novel way of interpreting the results of N-body simulations, where particles simply trace the evolution and distortion of Lagrangian phase-space volume elements. We discuss the advantages of this method over the widely used cloud-in-cells and adaptive-kernel smoothing density estimators. Applying the new method to a cluster-sized DM halo simulated in warm and cold DM scenarios, we show how the expected differences in their substructure popul...

  6. Phakic Pattern Pseudoexfoliation Material Accumulation on Intraocular Lens Surface

    Directory of Open Access Journals (Sweden)

    Emre Güler

    2014-03-01

    Full Text Available Pseudophakic pseudoexfoliation is the accumulation of pseudoexfoliation material on the intraocular lens. Most of the cases have showed scattered flecks of pseudoexfoliation material on the surface of the intraocular lens. However, the phakic pattern consisting of classic three-zone on the intraocular lens is rarely observed. In this case report, we describe a phakic pattern pseudoexfoliation material on the intraocular lens surface 8 years after cataract extraction. (Turk J Ophthalmol 2014; 44: 156-7

  7. Phakic Pattern Pseudoexfoliation Material Accumulation on Intraocular Lens Surface

    OpenAIRE

    Emre Güler; Aylin Tenlik; Tuba Kara Akyüz

    2014-01-01

    Pseudophakic pseudoexfoliation is the accumulation of pseudoexfoliation material on the intraocular lens. Most of the cases have showed scattered flecks of pseudoexfoliation material on the surface of the intraocular lens. However, the phakic pattern consisting of classic three-zone on the intraocular lens is rarely observed. In this case report, we describe a phakic pattern pseudoexfoliation material on the intraocular lens surface 8 years after cataract extraction. (Turk J Ophthalm...

  8. Comparison between OPD-scan results and contrast sensitivity of three intraocular lenses: spheric AcrySof SN60AT, aspheric AcrySof SN60WF and multifocal AcrySof Restor lens Estudo comparativo da análise de frente de onda e sensibilidade ao contraste entre as lentes intra-oculares multifocal AcrySof Restor SN60D3, monofocal AcrySof SN60WF asférica e a monofocal SN60AT esférica

    Directory of Open Access Journals (Sweden)

    Celso Takashi Nakano

    2009-08-01

    ção com implantes de lentes intraoculares AcrySof SN60D3 multifocal, AcrySof SN60WF monofocal asférica e AcrySof SA60AT monofocal esférica. Métodos: Trinta e dois olhos com a lente intraocular multifocal, 32 olhos com a lente intraocular monofocal asférica e 32 olhos com a lente intraocular monofocal esférica. A avaliação oftalmológica foi realizada no primeiro, terceiro, sétimo, e nonagésimo dia pós-operatório. Todos os exames foram padronizados, realizada por um único examinador sob condições controladas de luminosidade fotópicas estabelecidas em 85 cd/m², medida por meio de tabelas de ETDRS, sensibilidade ao contraste e análise de aberrometria com OPD-Scan. Resultados: As médias de aberração total foi superior no grupo SN60AT (KW = 9.42; p=0.009 quando comparada com o grupo SN60D3 (p=0.016 e o grupo SN60WF (p=0.0047. O grupo SN60AT (KW = 16.20; p=0.0003 apresentou superioridade nas medias de aberração esférica comparada com o grupo SN60WF (p=0.00046 e o grupo SN60D3 (p=0.0014. Nenhuma diferença significante foi encontrada na acuidade visual para longe com e sem correção óptica com a tabela de ETDRS a 100% e 9% de contraste. O grupo SN60D3 comparada a SN60AT (p=0.016 apresentou baixa sensibilidade ao contraste em condições fotópicas com diferença estatística a 6.0 cpg (KW = 7.84; p=0.0199, mas sem diferença estatística entre os grupos SN60WF e SN60AT (p=0.91 e entre os grupos SN60WF e SN60D3 (p=0.051. O grupo SN60D3 apresentou baixa sensibilidade ao contraste em condições mesópicas (KW = 10.79; p=0,0045 a 6cpg quando comparada com o grupos SN60AT (p=0.011 e SN60WF (p=0.007. Conclusão: As lentes intraoculares multifocais e asféricas apresentaram menos aberração esférica quando comparadas à lente intraocular esférica, além da prevista multifocalidade sem correção para longe e perto. Entretanto, o grupo multifocal apresentou baixa sensibilidade ao contraste.

  9. Capsulorhexis contraction after cataract surgery

    DEFF Research Database (Denmark)

    Corydon, Charlotte; Lindholt, Michael; Knudsen, Ellen B;

    2007-01-01

    PURPOSE: To evaluate the reduction in the anterior capsule opening after phacoemulsification, continuous curvilinear capsulorhexis, and implantation of 1 of 2 acrylic intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Vejle Hospital, Vejle, Denmark. METHODS: Eighty-four patients (84...

  10. Hydrophilic acrylic intraocular lens opacification after descemet stripping automated endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Amir Norouzpour

    2016-01-01

    Conclusion: In an eye with UZS and iatrogenic aniridia, IOL opacification may result from direct contact between the IOL surface and exogenous air. Aniridia can be a risk factor for development of IOL opacification after DSAEK. Further studies are required to confirm this hypothesis.

  11. 21 CFR 886.4300 - Intraocular lens guide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens guide. 886.4300 Section 886.4300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device...

  12. Clinical observation on visual quality in patients implanted with monofocal and multifocal aspheric intraocular lenses%多焦点与单焦点非球面人工晶状体植入后视觉质量的临床观察

    Institute of Scientific and Technical Information of China (English)

    王文莹; 王军; 张晶; 赵世强; 马剑欣

    2010-01-01

    眼近视力较好,阅读脱镜率较高,具有较好的视觉功能,但对比敏感度有所下降.%Objective To evaluate the visual quality in patients implanted with aspheric diffractive multifocal intraocular lens. Methods Prospective nonrandomized controlled study. One hundred cataract eyes in 50 patients were included. Patients received AcrySof IQ ReSTOR IOL (SN6AD3) or AcrySof IQ IOL (SN60WF) implantation. The follow up period was 6 months. The mean of unconnected distance visual acuity ( UCDVA) , best corrected distance visual acuity ( BCDVA), unconnected near visual acuity (UCNVA), best distance-corrected near visual acuity (BCNVA) and intermediate unconrrected visual acuity in patients with SN6AD3 and SN60WF was compared preoperatively and postoperatively in all patients. Photopic and mesopic contrast sensitivity function with and without glare were tested at 6 months after operation. Aberrations were recorded postoperatively. Subjective outcomes were assessed by VF-14 questionnaire. The chi-square test was applied to compare categorical variables and the paired-samples t test was used to compare the measure data. Results Postoperatively, there were no significant differences between groups in spherical equivalent (SE) (t=0.233, P = 0.876), UCDVA (t = 1.018, P=0.265) or BCNVA (t = 0. 679, P = 0. 501). The BCDVA in the monofocal IOL group was better than that in the multifocal IOL group (t = 2. 388, P = 0. 021). UCNVA improved remarkably after the implantation of multifocal IOL (t = 11. 311 ,P =0.000). The intermediate UCVA in the monofocal IOL eyes was butter than that in the multifocal IOL at 60 cm(t =2.414,P=0.020). The total aberration (F = 5. 169,P =0. 041), total low grade (F =4.973,P =0.036) and total high grade total aberrations (F =4.640,P = 0.048) were higher in the multifocal IOL group. There was no difference between these two groups in the defocus ( F = 0.862, P=0.358), astigmatism(F=3.893, P=0.052), spherical aberration(F = 1.743, P=0

  13. Meta-analysis of clinical randomized controlled trials comparing refractive with diffractive multifocal intraocular lenses in cataract surgery%折射型与衍射型多焦点人工晶状体临床应用效果随机临床对照试验的Meta分析

    Institute of Scientific and Technical Information of China (English)

    邵德望; 何守志

    2014-01-01

    及中距视力;衍射型MIOL表现出更好的裸眼近视力,出现光晕、眩光等视觉不良反应的可能性更小;在戴镜矫正状况下,衍射型MIOL与折射型MIOL的远、中、近视力表现相同.%Objective To systematic review the effectiveness of refractive multifocal intraocular lens (MIOL) versus diffractive MIOL in the treatment of cataract.Method Randomized controlled trials comparing refractive MIOL with diffractive MIOL were identified by searching PubMed (1966 to May,2013),EMbase (1980 to May,2013),Medline (1966 to May,2013),and The Cochrane Library (Issue 1,2013).We also hand-searched related journals.All the searches were restricted in English or Chinese.Methodological quality of randomized controlled trials (RCT) was evaluated by simple evaluate method that recommended by the Cochrane Collaboration.Data extracted by two reviewers with designed extraction form.RevMan software (release 5.2) was used for data management and analysis.Results A total of 11 trials (1460 eyes) were included for systematic review.Subgroup analyses were used according to different model comparison of MIOL.The results showed a significant difference in the mean of the uncorrected distance visual acuity (UCDVA) and the uncorrected intermediate visual acuity (UCIVA) in the refractive MIOLgroup with WMD-0.04,95% CI-0.06 to-0.03 (P <0.01) and WMD-0.05,95% CI-0.09 to-0.02 (P =0.001).It showed a significantly difference in the mean of the uncorrected near visual acuity (UCNVA),complete spectacle independent rate,halo rate and glare rate in the diffractive MIOL group with WMD 0.11,95% CI 0.08 to0.15 (P<0.01),WMD2.98,95%CI2.17 to4.09 (P<0.01),WMD 1.52,95% CI 1.14 to 2.04 (P =0.004) and WMD 1.27,95% CI 1.07 to 1.50 (P =0.005).There was no significant difference between the two groups in the mean of the best corrected distance visual acuity (BCDVA),the best distance corrected intermediate visual acuity (BDCIVA),the best distance corrected near visual

  14. Cross-correlating Planck CMB lensing with SDSS: Lensing-lensing and galaxy-lensing cross-correlations

    CERN Document Server

    Singh, Sukhdeep; Brownstein, Joel R

    2016-01-01

    We present first results from cross-correlating Planck CMB lensing maps with the Sloan Digital Sky Survey (SDSS) galaxy lensing shape catalog and BOSS galaxy catalogs. For galaxy position vs. CMB lensing cross-correlations, we measure the convergence signal around the galaxies in configuration space, using the BOSS LOWZ ($z\\sim0.30$) and CMASS ($z\\sim0.57$) samples. With fixed Planck 2015 cosmology, doing a joint fit with the galaxy clustering measurement, for the LOWZ (CMASS) sample we find a galaxy bias $b_g=1.75\\pm0.04$ ($1.95\\pm 0.02$) and galaxy-matter cross-correlation coefficient $r_{cc}=1.0\\pm0.2$ ($0.8\\pm 0.1$) using $20lensing. Using the same scales and including the galaxy-galaxy lensing measurements, we constrain $\\Omega_m=0.284\\pm0.024$ and relative calibration bias between the CMB lensing and galaxy lensing to be $b_\\gamma=0.82^{+0.15}_{-0.14}$. The combination of galaxy lensing and CMB lensing also allows us to measure the cosmolo...

  15. 阶梯渐进衍射型非球面多焦点人工晶状体植入术后的视觉质量研究%Clinical study of visual performance in patients with bilateral implantation of apodized diffractive aspheric multifocal intraocular lenses

    Institute of Scientific and Technical Information of China (English)

    孙懿; 郑丹莹; 宋婷婷

    2010-01-01

    ;阅读速度分别为(173.7±58.1)、(179.3±23.6)和(106.9±31.0)字/分,SN6AD1组和SN6AD3组均较SN60WF组快,差异有统计学意义(Z=-3.423,P=0.001;Z=-4.522,P=0.000).结论 SN6AD1和SN6AD3多焦点人工晶状体可以提供较SN60WF单焦点人工晶状体更好的近视力、40 cm及63 cm高低对比度裸眼中视力,以及更舒适的阅读距离和更快的阅读速度.SN6AD1人工晶状体能提供较SN6AD3更优秀的40 cm及63 cm高低对比度中视力.%Objective To evaluate visual performance after bilateral implantation with either the AcrySof ReSTOR SN6AD1 multifocal intraocular lens (MIOL) or the AcrySof ReSTOR SN6AD3 MIOL. Methods This was a prospective case series study. Sixty age-related cataract patients (120eyes) at the Zhongshan Ophthalmic Center from June 2009 to April 2010 were enrolled in this study.Based on the principal of voluntary choice, phacoemulsification combined with IOL implantation was performed. There were 20 patients (40 eyes) in each group, the SN6AD1 MIOL group, SN6AD3MIOL group and SN60WF group. There were 8 male patients and 12 female patients (8/12) in the SN6AD1 group, and 10/10 and 11/9 in the SN6AD3 and SN60WF groups, respectively. The average ages in years were 64.6±12.7, 67.5±8.5, and 61.1±11.0, respectively. Uncorrected near visual acuity (UCNVA), uncorrected intermediate visual acuity (UCIVA) under high and low contrast conditions,uncorrected distance visual acuity (UCDVA), uncorrected near visual acuity for Chinese characters under high and low contrasts, contrast sensitivity, preferred reading distance and reading speeds were assessed 3 months postoperatively. A one-way ANOVA, Bonferroni, rank-sum test or independent samples t test was used to analyze the data. Results UCNVA was (0.074±0.862)logMAR for the SN6AD1 group and was (0.075±0.772)logMAR for the SN6AD3 group, which was significantly better than the (0.351±0.691)logMAR for the SN60WF group (Z=-6.756, P=0.000; Z=-6.508, P=0.000).Significant differences were found for

  16. Morphological Findings of Intraocular Lens with Haptics Detached from Optics Following Cataract Surgery.

    Science.gov (United States)

    Suzuki, Yukihiko; Suzuki, Kaori; Metok, Tomomi; Nakazawai, Mitsuru

    2010-03-09

    A 55-year-old woman was treated using phacoemulsification, aspiration, and intraocular lens (IOL) implantation. Three months after surgery, the optical zone of the anterior capsule was completely closed due to strong capsular contractions. As the two haptics were found to be completely detached from the optics, the IOL was subsequently extracted and morphologically examined. Although the optics and haptics of the IOL when viewed with a stereomicroscope appeared to have no marked damage on their surfaces, an ultra-structural examination showed that a portion of the acrylic optics on the detached surface was defective. We considered that the IOL haptics might have become detached from the optics due to continuous force from postoperative capsular contractions.

  17. Clinical research of postoperative visual quality in AURIUM photochromic intraocular lens implantation%AURIUM光致变色人工晶状体植入术后视觉质量的临床研究

    Institute of Scientific and Technical Information of China (English)

    熊宇; 刘菲; 张倩; 王彪; 付书华

    2012-01-01

    目的 观察光致变色人工晶状体(MATRIX Acrylic AURIUM 400)与非球面蓝光滤过型人工晶状体(AcrySof IQ)对视力,色觉分辨力及对比敏感度的影响.方法 接受手术的白内障患者122例122只眼按照随机数字表分为两组,白内障超声乳化分别植入MATRIX Acrylic AURIUM 400(62只眼)和AcrySof IQ(60只眼),术后3月检查患者裸眼视力(UCVA),最佳矫正视力(BCVA),色觉分辨力,对比敏感度(CSV-1000E),并填写调查问卷(Catquest-9SF).结果 术后3个月,两组患者UCVA、BCVA及调查问卷分值差异均无统计学意义(P均≥0.05).两组患者色觉无异常.Aurium组在暗适应眩光条件下眩光对比敏感度(空间频率3 cpd、6c pd)分别为1.30+0.11、1.38+0.19、要优于IQ组1.16+0.12、1.10+0.18,差异有统计学意义(P<0.05).结论 在暗环境眩光条件下,Aurium人工晶状体能够提供较好的视觉质量.%Objective To investigate the difference in visual acuity,the color discrimination and contrast sensitivity function after Matrix Acrylic 400 photochromic IOLs and aspherical blue-light-filtering intraocular lenses (Acrysof IQ) implantation.Methods Patients were randomly divided into 2 groups according to random number table.Phacoemulsification and IOL implantation were applied to patients with Matrix Acrylic 400 in 62 eyes and AcrySof IQ in 60 eyes,respectively.All patients were followed up for 3 months.General examinations including uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),color discrimination,contrast sensitivity (csv-1000E) and questionnaire (Catquest-9SF score) were applied at the 3rd month post-operation.Results UCVA,BCVA,color discrimination and questionnaire results were similar between the two groups (P ≥0.05).In mesopic with glare condition,Aurium photochromic group showed significantly higher GS (3cpd/6cpd spatial frequency:1.30+0.11/1.38+0.19) than IQ (3cpd/6cpd spatial frequency:1.16+0.12/1.10+0.18) (P <0.05).Conclusions The

  18. Weak lensing by voids in modified lensing potentials

    CERN Document Server

    Barreira, Alexandre; Li, Baojiu; Baugh, Carlton; Pascoli, Silvia

    2015-01-01

    We study lensing by voids in Cubic Galileon and Nonlocal gravity cosmologies, which are examples of theories of gravity that modify the lensing potential. We find voids in the dark matter and halo density fields of N-body simulations and compute their lensing signal analytically from the void density profiles, which we show are well fit by a simple analytical formula. In the Cubic Galileon model, the modifications to gravity inside voids are not screened and they approximately double the size of the lensing effects compared to GR. The difference is largely determined by the direct effects of the fifth force on lensing and less so by the modified density profiles. For this model, we also discuss the subtle impact on the force and lensing calculations caused by the screening effects of haloes that exist in and around voids. In the Nonlocal model, the impact of the modified density profiles and the direct modifications to lensing are comparable, but they boost the lensing signal by only $\\approx 10\\%$, compared ...

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

    Science.gov (United States)

    Hassan, Alahmady Hamad Alsmman; Sayed, Khulood M.; ElAgooz, Mohammed; Elhawary, Ashraf Mostafa

    2016-01-01

    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. PMID:27313869

  20. Roulettes: A weak lensing formalism for strong lensing - I. Overview

    CERN Document Server

    Clarkson, Chris

    2016-01-01

    We present a new perspective on gravitational lensing. We describe a new extension of the weak lensing formalism capable of describing strongly lensed images. By integrating the non-linear geodesic deviation equation, the amplification matrix of weak lensing is generalised to a sum over independent amplification tensors of increasing rank. We show how an image distorted by a generic lens may be constructed as a sum over `roulettes', which are the natural curves associated with the independent spin modes of the amplification tensors. Highly distorted images can be constructed even for large sources observed near or within the Einstein radius of a lens where the shear and convergence are large. The amplitude of each roulette is formed from a sum over appropriate derivatives of the lensing potential. Consequently, measuring these individual roulettes for images around a lens gives a new way to reconstruct a strong lens mass distribution without requiring a lens model. This formalism generalises the convergence, ...

  1. RHIC electron lenses upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Binello, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Costanzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Pikin, A. I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Shrey, T. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tan, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  2. 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.

  3. 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.

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

    Science.gov (United States)

    Can, Ertuğrul; Koçak, Nurullah; Yücel, Özlem Eşki; Gül, Adem; Öztürk, Hilal Eser; Sayın, Osman

    2016-01-01

    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. PMID:27050346

  5. Radiation curing applications of palm oil acrylates

    International Nuclear Information System (INIS)

    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)

  6. Associations with intraocular pressure across Europe

    DEFF Research Database (Denmark)

    Khawaja, Anthony P; Springelkamp, Henriët; Creuzot-Garcher, Catherine;

    2016-01-01

    Raised intraocular pressure (IOP) is the most important risk factor for developing glaucoma, the second commonest cause of blindness globally. Understanding associations with IOP and variations in IOP between countries may teach us about mechanisms underlying glaucoma. We examined cross-sectional...

  7. In vitro evaluation of chemically cross-linked shape-memory acrylate-methacrylate copolymer networks as ocular implants.

    Science.gov (United States)

    Song, Li; Hu, Wang; Zhang, Hongbin; Wang, Guojie; Yang, Huai; Zhu, Siquan

    2010-06-01

    Acrylates have been used in ophthalmic practice as a paradigmatic implant material for decades, especially as intraocular lens for their excellent transparency. A novel polymeric shape memory system of chemically cross-linked acrylate-methacrylate copolymer networks was developed and characterized in this study. The thermomechanical properties, shape memory properties, transparency, and surface wettability as well as cytotoxicity were systematically evaluated to mimic the in vivo situation by differential scanning calorimetry (DSC), tensile tests, spectrophotometer, Abbe refractometer, contact angle measurements, and MTT assay. It was found that the chemically cross-linked copolymer network behaves as an elastomer capable of arbitrary shaping above the glass-transition temperature. Transition temperatures of the networks were tunable through the change of the composition of monomers. PMID:20462221

  8. Magnetic electron lenses

    CERN Document Server

    1982-01-01

    No single volume has been entirely devoted to the properties of magnetic lenses, so far as I am aware, although of course all the numerous textbooks on electron optics devote space to them. The absence of such a volume, bringing together in­ formation about the theory and practical design of these lenses, is surprising, for their introduction some fifty years ago has created an entirely new family of commercial instruments, ranging from the now traditional transmission electron microscope, through the reflection and transmission scanning microscopes, to co­ lumns for micromachining and microlithography, not to mention the host of experi­ mental devices not available commercially. It therefore seemed useful to prepare an account of the various aspects of mag­ netic lens studies. These divide naturally into the five chapters of this book: the theoretical background, in which the optical behaviour is described and formu­ lae given for the various aberration coefficients; numerical methods for calculat­ ing...

  9. Characterizing intraocular tumors with photoacoustic imaging

    Science.gov (United States)

    Xu, Guan; Xue, Yafang; Gursel, Zeynep; Slimani, Naziha; Wang, Xueding; Demirci, Hakan

    2016-03-01

    Intraocular tumors are life-threatening conditions. Long-term mortality from uveal melanoma, which accounts for 80% of primary intraocular tumors, could be as high as 25% depending on the size, ciliary body involvement and extraocular extension. The treatments of intraocular tumors include eye-sparing approaches such as radiotherapy and thermotherapy, and the more aggressive enucleation. The accurate diagnosis of intraocular tumors is thereby critical in the management and follow-up of the patients. The diagnosis of intraocular tumors is usually based on clinical examination with acoustic backscattering based ultrasonography. By analyzing the high frequency fluctuations within the ultrasound (US) signals, microarchitecture information inside the tumor can be characterized. However, US cannot interrogate the histochemical components formulating the microarchitecture. One representative example is the inability of US imaging (and other contemporary imaging modalities as well) in differentiating nevoid and melanoma cells as the two types of cells possesses similar acoustic backscattering properties. Combining optical and US imaging, photoacoustic (PA) measurements encode both the microarchitecture and histochemical component information in biological tissue. This study attempts to characterize ocular tumors by analyzing the high frequency signal components in the multispectral PA images. Ex vivo human eye globes with melanoma and retinoblastoma tumors were scanned using less than 6 mJ per square centimeters laser energy with tunable range of 600-1700 nm. A PA-US parallel imaging system with US probes CL15-7 and L22-14 were used to acquire the high frequency PA signals in real time. Preliminary results show that the proposed method can identify uveal melanoma against retinoblastoma tumors.

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

    Directory of Open Access Journals (Sweden)

    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

  11. Roulettes: a weak lensing formalism for strong lensing: I. Overview

    Science.gov (United States)

    Clarkson, Chris

    2016-08-01

    We present a new perspective on gravitational lensing. We describe a new extension of the weak lensing formalism capable of describing strongly lensed images. By integrating the nonlinear geodesic deviation equation, the amplification matrix of weak lensing is generalised to a sum over independent amplification tensors of increasing rank. We show how an image distorted by a generic lens may be constructed as a sum over ‘roulettes’, which are the natural curves associated with the independent spin modes of the amplification tensors. Highly distorted images can be constructed even for large sources observed near or within the Einstein radius of a lens where the shear and convergence are large. The amplitude of each roulette is formed from a sum over appropriate derivatives of the lensing potential. Consequently, measuring these individual roulettes for images around a lens gives a new way to reconstruct a strong lens mass distribution without requiring a lens model. This formalism generalises the convergence, shear and flexion of weak lensing to arbitrary order, and provides a unified bridge between the strong and weak lensing regimes. This overview paper is accompanied by a much more detailed paper II, arXiv:1603.04652.

  12. Management of dislocated intraocular implants.

    Science.gov (United States)

    Chan, C K; Agarwal, A; Agarwal, S; Agarwal, A

    2001-12-01

    Implant dislocation may occur in the absence of appropriate capsular or zonular support (PCIOL) (11,35,53) or following traumatic injury to anterior ocular tissues (ACIOL). (11,19,20) Other factors (e.g., advanced patient age, high myopia, previous vitrectomy, pseudoexfoliation syndrome, and certain connective tissue disorders) also may predispose implant dislocation. (9,52) Although reported for all types of IOLs, implant dislocation is becoming more manageable because of the advancement of surgical techniques. A dislocated ACIOL or PCIOL may be explanted, exchanged, or repositioned. (11,48,71) Repositioning the dislocated PCIOL in the ciliary sulcus with modern vitreoretinal techniques provides an optimal environment for visual recovery. (11,71) Implant repositioning techniques generally may be categorized into the external or the internal approaches. (8,11) The former involves external suturing methods for a primary or secondary implant in the absence of adequate capsular or zonular support (15,16,31,42,56,60,61,64,66,73,76) and the latter is achieved through modern pars plana techniques. 8,11,62,69) Recently, several implant repositioning methods gaining increasing acceptance include the scleral loop fixation, (45) the snare approach, (43) the use of the 25-gauge implant forceps, (13) temporary haptic externalization, (8,11,36,71) and the use of perfluorocarbon liquids. (1,28,40,41,44) The temporary haptic externalization method combines the best features of the external and the internal approaches, avoids complex intraocular maneuvers, and allows precise scleral fixation of the dislocated IOL on a consistent basis. (8,11,71) Endoscopy provides the surgeon with optimal viewing of the anterior retropupillary anatomy that is often difficult to appreciate (e.g., capsular-zonular complex, ciliary sulcus, anterior retina, and vitreous base). (6,11) As a result, precise haptic placement is possible during the repositioning process. (6,11) However, a three

  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. LENSED: a code for the forward reconstruction of lenses and sources from strong lensing observations

    Science.gov (United States)

    Tessore, Nicolas; Bellagamba, Fabio; Metcalf, R. Benton

    2016-09-01

    Robust modelling of strong lensing systems is fundamental to exploit the information they contain about the distribution of matter in galaxies and clusters. In this work, we present LENSED, a new code which performs forward parametric modelling of strong lenses. LENSED takes advantage of a massively parallel ray-tracing kernel to perform the necessary calculations on a modern graphics processing unit (GPU). This makes the precise rendering of the background lensed sources much faster, and allows the simultaneous optimisation of tens of parameters for the selected model. With a single run, the code is able to obtain the full posterior probability distribution for the lens light, the mass distribution and the background source at the same time. LENSED is first tested on mock images which reproduce realistic space-based observations of lensing systems. In this way, we show that it is able to recover unbiased estimates of the lens parameters, even when the sources do not follow exactly the assumed model. Then, we apply it to a subsample of the SLACS lenses, in order to demonstrate its use on real data. The results generally agree with the literature, and highlight the flexibility and robustness of the algorithm.

  15. Optimizing distance image quality of an aspheric multifocal intraocular lens using a comprehensive statistical design approach.

    Science.gov (United States)

    Hong, Xin; Zhang, Xiaoxiao

    2008-12-01

    The AcrySof ReSTOR intraocular lens (IOL) is a multifocal lens with state-of-the-art apodized diffractive technology, and is indicated for visual correction of aphakia secondary to removal of cataractous lenses in adult patients with/without presbyopia, who desire near, intermediate, and distance vision with increased spectacle independence. The multifocal design results in some optical contrast reduction, which may be improved by reducing spherical aberration. A novel patent-pending approach was undertaken to investigate the optical performance of aspheric lens designs. Simulated eyes using human normal distributions were corrected with different lens designs in a Monte Carlo simulation that allowed for variability in multiple surgical parameters (e.g. positioning error, biometric variation). Monte Carlo optimized results indicated that a lens spherical aberration of -0.10 microm provided optimal distance image quality.

  16. 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.

  17. Acrylates and methacrylates of formal-glycerine

    International Nuclear Information System (INIS)

    Present article is devoted acrylates and methacrylates of formal-glycerine. The formal-glycerine was obtained in the form of mixture of isomers 1.2 and 1.3 from glycerine and paraform with hydrochloric acid. The structure of obtained acrylates and methacrylates is studied by means of molecular refraction, element analysis and infrared spectroscopy.

  18. Lenses for JWST

    Science.gov (United States)

    Ebeling, Harald; Richard, Johan; Kneib, Jean-Paul; Repp, Andrew; Atek, Hakim; Egami, Eiichi; Windhorst, Rogier; Edge, Alastair

    2016-08-01

    JWST will dramatically advance our knowledge and understanding of the first generations of galaxies at z>10, their role in the re-ionization of the Universe, and the evolutionary processes that gave rise to the complexity and diversity of galaxies at the current epoch. As demonstrated by HST legacy projects like CLASH and the Hubble Frontier Fields, gravitational amplification by massive galaxy clusters can significantly extend the depth of the required observations. However, for JWST, reducing any diffuse background light will be just as crucial. We here propose Spitzer/IRAC observations of six massive cluster lenses, specifically selected as candidates for observation with JWST. By (a) quantifying the amount of intra-cluster light and (b) enabling us to improve our current lens models, the data resulting from the requested observations will be instrumental for the final selection of cluster targets that maximize the scientific returns of deep JWST observations.

  19. Bayesian Lensing Shear Measurement

    CERN Document Server

    Bernstein, Gary M

    2013-01-01

    We derive an estimator of weak gravitational lensing shear from background galaxy images that avoids noise-induced biases through a rigorous Bayesian treatment of the measurement. The Bayesian formalism requires a prior describing the (noiseless) distribution of the target galaxy population over some parameter space; this prior can be constructed from low-noise images of a subsample of the target population, attainable from long integrations of a fraction of the survey field. We find two ways to combine this exact treatment of noise with rigorous treatment of the effects of the instrumental point-spread function and sampling. The Bayesian model fitting (BMF) method assigns a likelihood of the pixel data to galaxy models (e.g. Sersic ellipses), and requires the unlensed distribution of galaxies over the model parameters as a prior. The Bayesian Fourier domain (BFD) method compresses galaxies to a small set of weighted moments calculated after PSF correction in Fourier space. It requires the unlensed distributi...

  20. [Laser scan microscopy: a new imaging procedure in quality assessment of artificial lenses].

    Science.gov (United States)

    Rochels, R; Ziegler, E

    1989-01-01

    Laser-scan microscopy permits the evaluation of surfaces and deeper layers of an object by computer-assisted scanning with a laser beam. The reflected helium-neon or argon laser light is transmitted to a photodetector and after signal processing, to a frame store and a TV monitor. Imaging is realized by synchronous scanning and modulation of light intensity. Laser-scan microscopy revealed a smooth surface of both PMMA and HEMA lenses, whereas tears were detected in folded silicone implants. The physical and chemical homogeneity inside the three different materials was optimal. Compared to scanning electron microscopy, the quality of imaging is not as good with laser-scan microscopy. Nevertheless, one decisive advantage of the latter method is an analysis free of processing and artifacts, which permits a routine control of brand new and folded intraocular lenses. PMID:2722098

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

    Directory of Open Access Journals (Sweden)

    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

  2. Iris-claw intraocular lens implantation: Anterior chamber versus retropupillary implantation

    Science.gov (United States)

    Helvacı, Sezer; Demirdüzen, Selahaddin; Öksüz, Hüseyin

    2016-01-01

    Purpose: To compare the outcomes of anterior chamber and retropupillary implantation of iris-claw Artisan intraocular lenses (IOL). Design: Prospective, randomized, single-blinded study. Patients and Methods: Forty eyes of forty aphakic patients were enrolled. Patients were randomized into two groups. Each group includes twenty patients. Group 1 received anterior chamber Artisan IOL implantation. Group 2 received retropupillary Artisan IOL implantation. Preoperative and postoperative corrected distance visual acuity (CDVA), intraocular pressure (IOP), and all complications were noted and compared at 6 months follow-up. Results: Each two groups obtained a significant improvement in CDVA (P < 0.05). Four patients in Group 1 and five patients in Group 2 had significant but nonpermanent increase at IOP values. There were one and two pupillary irregularity in Group 1 and Group 2, respectively. In one patient, a shallow and inferior located retinal detachment were encountered in anterior chamber group. Conclusions: The results were not significantly different between the two fixation techniques for iris-claw lens. The surgery procedure is dependent to surgeon experience and eye's conditions. PMID:26953023

  3. Lensed: a code for the forward reconstruction of lenses and sources from strong lensing observations

    CERN Document Server

    Tessore, Nicolas; Metcalf, R Benton

    2015-01-01

    Robust modelling of strong lensing systems is fundamental to exploit the information they contain about the distribution of matter in galaxies and clusters. In this work, we present Lensed, a new code which performs forward parametric modelling of strong lenses. Lensed takes advantage of a massively parallel ray-tracing kernel to perform the necessary calculations on a modern graphics processing unit (GPU). This makes the precise rendering of the background lensed sources much faster, and allows the simultaneous optimisation of tens of parameters for the selected model. With a single run, the code is able to obtain the full posterior probability distribution for the lens light, the mass distribution and the background source at the same time. Lensed is first tested on mock images which reproduce realistic space-based observations of lensing systems. In this way, we show that it is able to recover unbiased estimates of the lens parameters, even when the sources do not follow exactly the assumed model. Then, we...

  4. 人工晶体眼异常眩光幻影的研究进展%Research Progress in Pseudophakic Dysphotopsia Associated with Intraocular Lens

    Institute of Scientific and Technical Information of China (English)

    吴来伟

    2011-01-01

    Dysphotopsia ( glare, halos and shadows ) associated with intraocular lenses can degrade the visual performance following cataract surgery. Pseudophakic dysphotopsia is caused by four factors, including intraocular lens design, surgical factors, patient physical factors, and central adaptation. Positive dysphotopsia can be minimized by a larger optic, textured intraocular lens edge, optiEdge edge, and lower posterior capsule opacification. Besides, incision location, and iris - intraocular lens distance may play an important role in negative dysphotopsia. For the treatment of dysphotopsia,six months of clinical observation is necessary. Patients with severe and persistent dysphotopsia need to replace intraocular lens or to implant a piggyback intraocular lens in the ciliary sulcus.%白内障术后发生的眩光、光晕、阴影等眩光幻影问题成为影响视觉质量的重要因素.影响人工晶体眼眩光幻影的因素有晶体设计、手术因素、患者生理因素和心理适应.预防后发性白内障、晶体边缘纹理化、采用前圆后方边缘设计、使用更大的晶体光学面可以减少正像眩光幻影的发生.而手术切口位置和虹膜-晶体间距等可能是负像眩光幻影产生的影响因素.对于眩光幻影的治疗,6个月的临床观察是必要的,症状严重且持续者可考虑晶体置换或睫状沟植入另一枚驼背式人工晶体.

  5. Intraocular pressure in Japanese diabetic patients

    OpenAIRE

    Matsuoka M; Ogata N.; Matsuyama K; Yoshikawa T.; Takahashi K.

    2012-01-01

    Masato Matsuoka,1 Nahoko Ogata,2 Kayako Matsuyama,1 Tadanobu Yoshikawa,1 Kanji Takahashi31Department of Ophthalmology, Kansai Medical University, Takii Hospital, Osaka, 2Department of Ophthalmology, Nara Medical University, Nara, 3Department of Ophthalmology, Kansai Medical University, Hirakata Hospital, Osaka, JapanBackground: To determine whether the intraocular pressure (IOP) in diabetic patients is significantly different from that in nondiabetic patients.Methods: The medical records of a...

  6. Environmental standards for intraocular lens implantation.

    Science.gov (United States)

    Crawford, B A; Kaufman, D V

    1984-02-01

    Successful implantation of prosthetic devices depends upon their freedom from postoperative inflammation and infection. Techniques and lessons learned in orthopaedic and other implant surgery should be applied to intraocular lens implantation. The avoidance of contamination by particles and micro-organisms is one essential principle of the surgical procedure. Practical steps are described to reduce both types of contamination. These measures taken together are recommended for adoption as a standard of environmental safety for lens implantation.

  7. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    OpenAIRE

    Elena Bonafonte Marquez; Sergio Bonafonte Royo

    2015-01-01

    We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL) implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for i...

  8. Introduction to the development of intraocular lens

    Science.gov (United States)

    Li, Yifan; Peng, Runling; Hu, Shuilan; Wei, Maowei; Chen, Jiabi

    2013-08-01

    In order to cure the cataract disease or injuries in eyes, intraocular lens(IOL) has been studied all the time to replace the crystalline lens in human eyes. Researches on IOL are started early from 19th century, and it develops greatly in the hundreds years after. This article introduces several main kinds of IOLs that appear in the development history of IOL, and raises the double-liquid zoom IOL based on electrowetting, which will be the trend of IOL study.

  9. On Perfect Lenses and Nihility

    CERN Document Server

    Lakhtakia, A

    2002-01-01

    The canonical problem of a perfect lens with linear bianisotropic materials is formulated. Its solution is shown to be directly connected with the concept of nihility, the electromagnetic nilpotent. Perfect lenses as well as nihility remain unrealizable.

  10. Planar Lenses at Visible Wavelengths

    CERN Document Server

    Khorasaninejad, Mohammadreza; Devlin, Robert C; Oh, Jaewon; Zhu, Alexander Y; Capasso, Federico

    2016-01-01

    Sub-wavelength resolution imaging requires high numerical aperture (NA) lenses, which are bulky and expensive. Metasurfaces allow the miniaturization of conventional refractive optics into planar structures. We show that high-aspect-ratio titanium dioxide metasurfaces can be fabricated and designed as meta-lenses with NA = 0.8. Diffraction-limited focusing is demonstrated at wavelengths of 405 nm, 532 nm, and 660 nm with corresponding efficiencies of 86%, 73%, and 66%. The meta-lenses can resolve nanoscale features separated by sub-wavelength distances and provide magnification as high as 170x with image qualities comparable to a state-of-the-art commercial objective. Our results firmly establish that meta-lenses can have widespread applications in laser-based microscopy, imaging, and spectroscopy.

  11. Effect of a tight necktie on intraocular pressure

    OpenAIRE

    Božić Marija; Hentova-Senćanin Paraskeva; Branković Aleksandra; Marjanović Ivan; Jocić Đorđević Jasmina; Senćanin Ivan

    2012-01-01

    Introduction. Any factor causing constriction of the neck may lead to an increase in intraocular pressure. A tight necktie may result in increasing intraocular pressure, which could lead to an erroneous diagnosis and treatment of ocular hypertension or even glaucoma. This study was aimed at evaluating the effect of a tight necktie on intraocular pressure measurement using Goldmann applanation tonometry. Material and Methods. This study included forty eyes of 20 patients with primary ope...

  12. VISUAL ACUITY AND CLINICAL REFRACTION FOLLOWING IMPLANTATION OF VARIOUS MULTIFOCAL INTRAOCULAR LENSES

    Directory of Open Access Journals (Sweden)

    N. N. Temirov

    2015-01-01

    Full Text Available Aim. To analyze visual acuity, clinical refraction, and defocusing tolerance after the implantation of monofocal IOL with rotational asymmetric optic (Lentis Mplus 313 MF compared with Acrysof ReSTOR SN6AD1.Materials and methods. Phacoemulsification was performed in a total of 194 patients (288 eyes, i.e., 144 patients (188 eyes with cataract and 50 patients (100 eyes with presbyopia and high ametropia. The patients were divided into two groups. Study group included 132 patients (194 eyes implanted with Lentis Mplus while control group included 62 patients (94 eyes implanted with Acrysof ReSTOR. Uncorrected distance (5 m, intermediate (50‑70 cm, and near (20‑40 cm visual acuity under photopic (85 cd/m2 and mesopic (8 cd/m2 conditions were measured, objective and subjective refractometry were performed, and defocusing tolerance was evaluated.Results. Postoperatively, uncorrected distance and near visual acuity was high while intermediate visual acuity was moderately low. Lentis Mplus patients had better near and intermediate visual acuity under mesopic conditions as compared with Acrysof ReSTOR patients. Emmetropia (target refraction was achieved in 90.2% of study group patients and in 87.2% of control group patients. In patients implanted with Lentis Mplus, refraction was measured by subjective method. Optimal A-constant for Lentis Mplus and Acrysof ReSTOR was 118.0 and 118.6, respectively. Under defocusing, Lentis Mplus patients had better visual acuity than Acrysof ReSTOR patients. This indirectly confirms better intermediate vision.Conclusions. Lentis Mplus provides better vision at various distances that does not almost depend on light levels and induces minimal dysphotopsia. 

  13. VISUAL ACUITY AND CLINICAL REFRACTION FOLLOWING IMPLANTATION OF VARIOUS MULTIFOCAL INTRAOCULAR LENSES

    OpenAIRE

    N. N. Temirov; N. E. Temirov

    2015-01-01

    Aim. To analyze visual acuity, clinical refraction, and defocusing tolerance after the implantation of monofocal IOL with rotational asymmetric optic (Lentis Mplus 313 MF) compared with Acrysof ReSTOR SN6AD1.Materials and methods. Phacoemulsification was performed in a total of 194 patients (288 eyes), i.e., 144 patients (188 eyes) with cataract and 50 patients (100 eyes) with presbyopia and high ametropia. The patients were divided into two groups. Study group included 132 patients (194 eyes...

  14. Primary and secondary implantation of scleral-fixated posterior chamber intraocular lenses in adult patients

    Directory of Open Access Journals (Sweden)

    Zuleyha Yalniz-Akkaya

    2014-01-01

    Conclusion: Both primary and secondary scleral-fixated PCIOL implantations can provide favorable visual outcomes with lower complication rates. An important consideration is the appropriate timing for scleral fixation, taking into account the patient′s characteristics and the course of the operation.

  15. Radiopurity measurement of acrylic for DEAP-3600

    International Nuclear Information System (INIS)

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from 238U and 232Th. Another background of particular concern is diffusion of 222Rn during manufacturing, leading to 210Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of 238U and 232Th equivalent, and 10−8 ppt 210Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented

  16. Radiopurity measurement of acrylic for DEAP-3600

    Energy Technology Data Exchange (ETDEWEB)

    Nantais, C. M.; Boulay, M. G. [Department of Physics, Engineering Physics, and Astronomy, Queen' s University, Kingston, Ontario K7L 3N6 (Canada); Cleveland, B. T. [SNOLAB, Lively, Ontario P3Y 1N2 Canada and Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

    2013-08-08

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from {sup 238}U and {sup 232}Th. Another background of particular concern is diffusion of {sup 222}Rn during manufacturing, leading to {sup 210}Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of {sup 238}U and {sup 232}Th equivalent, and 10{sup −8} ppt {sup 210}Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented.

  17. Occupational respiratory disease caused by acrylates.

    Science.gov (United States)

    Savonius, B; Keskinen, H; Tuppurainen, M; Kanerva, L

    1993-05-01

    Acrylates are compounds used in a variety of industrial fields and their use is increasing. They have many features which make them superior to formerly used chemicals, regarding both their industrial use and their possible health effects. Contact sensitization is, however, one of their well known adverse health effects but they may also cause respiratory symptoms. We report on 18 cases of respiratory disease, mainly asthma, caused by different acrylates, 10 cases caused by cyanoacrylates, four by methacrylates and two cases by other acrylates. PMID:8334539

  18. 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

  19. Opaque perfect lenses

    CERN Document Server

    Milton, G W; McPhedran, R C; Milton, Graeme W.; Nicorovici, Nicolae-Alexandru P.; Phedran, Ross C. Mc

    2006-01-01

    The response of the ``perfect lens'', consisting of a slab of lossless material of thickness $d$ with $\\epsilon=\\mu=-1$ at one frequency $\\omega_0$ is investigated. It is shown that as time progresses the lens becomes increasingly opaque to any physical TM line dipole source located a distance $d_0lenses in the low loss limit. Contrary to the usual picture where the field intensity has a minimum at the front interface we find that the field diverges to infinity there in the long time constant limit.

  20. 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.

  1. Clinical analysis of 49 cases with intraocular lens dislocation%人工晶状体脱位49例临床分析

    Institute of Scientific and Technical Information of China (English)

    王海燕; 庞秀琴; 何雷; 裴雪婷; 王绍莉; 卢海

    2012-01-01

    Objective To discuss the clinical characteristics of intraocular lens (IOL) dislocation. Design Retrospective cases series. Participants 49 eyes (49 cases) of intraocular lens dislocation in Beijing Tongren Hospital from 2004 to 2011. Methods Clinical data of intraocular lens dislocation were reviewed retrospectively. Main Outcome Measures Age, original disease, history of disease, position and type of intraocular lens, cause, surgical method, and complication. Results Majority of 49 cases of intraocular lens dislocation were cases with surgery of age-related cataract (46.9%) and traumatic cataract (28.6%). 6 cases with dislocation of intraocular lens with ciliary sulcus fixation happened 1 year after surgery. Majority of intraocular lenses dislocated located in vitreous body (53.1%) and "C" loop (89.8%). 75.5% of causes were original disease and surgery. Ciliary sulcus fixation or re-fixation of intraocular lens (47 eyes, 95.9%) could achieve good centration and stability of the intraocular lens. Naked vision of 0.1 or more accounted for 59.6% at 2 weeks after fixation or re-fixation. Conclusion Intraocular lens dislocation is related with original disease and surgery. Ciliary sulcus fixation of intraocular lens is an effective strategy to treat intraocular lens dislocation. But intraocular lens with ciliary sulcus fixation still happens to dislocate. (Ophthalmol CHN, 2012, 21: 47-51)%目的 探讨人工晶状体(IOL)脱位的临床特点.设计 回顾性病例系列.研究对象 北京同仁医院2004-2011年治疗的IOL脱位49例49眼.方法 对IOL脱位患者的临床资料进行同顾性分析.主要指标 年龄、原IOL植入原因,发病时间,脱位IOL位置及类型,IOL脱位诱因,手术治疗方法及并发症.结果 49眼IOL脱位中,老年性白内障和外伤性白内障摘除联合IOL植入术者较多,分别占46.9%、28.6%.6例睫状沟固定IOL脱位均发生于手术1年后.脱位IOL53.1%位于玻璃体腔内.89.8

  2. Comparison of Trans-scleral Fixation of PMMA and Foldable Intraocular Lens in Children

    Institute of Scientific and Technical Information of China (English)

    Yuping Zou; Zhende Lin; Bo Feng; Shaozhen Li

    2001-01-01

    Purpose: To observe the difference of the effects of PMMA and foldable intraocular lenses (IOLs) trans-sclerally fixed in pediatric eyes. Methods: Thirty-two children (43 eyes) who had undergone trans-scleral fixation of IOL were retrospected, of whom 5 children were implanted PMMA IOL in both eyes, 6children were implanted PMMA IOL in one eye and foldable IOL in the other eye, 12children were implanted foldable IOL in one eye and 9 chilrden were implanted PMMA IOL in one eye. Mean age was 5.3 years ( range 2.5 ~ 12 years ). Twelve children had traumatic cataract and the others congenital cataract before lens extraction. Results: Foldable group (18 eyes ): Mean follow-up was 12.1 months. Visual acuity (VA): compared with the best corrected VA before IOL fixation, postoperative best corrected VA improved in 16 eyes, remained unchanged in 2 eyes. In 14 eyes, one or two stitches were needed to seal the incision. Complications: Severe anterior chamber reaction was seen in 3 eyes. Intraocular bleeding was found in 3 eyes. IOL decentration was detected in 1 eye. Iris capture of IOL was seen in one eye. PMMA group (25 eyes ):Mean follow-up was 20.3 months. Visual acuity (VA): compared with the best corrected VA before IOL fixation, postoperative best corrected VA improved in 19 eyes,remained unchanged in 5 eyes and got worse in one eye. In 24 eyes, one to three stitches were needed to seal the incision. Complications: Severe anterior chamber reaction was seen in 5 eyes. Intraocular bleeding was found in 4 eyes. IOL decentration was seen in one eye. Iris capture of IOL was seen in 3 eyes. Intraocular pressure elevated in one eye. Conclusion: Our study shows that trans-scleral fixation of IOL is a safe procedure in pediatric eyes. Foldable IOL showed similar effect compared with PMMA IOL in pediatric trans-scleral fixation. Eye Science 2001; 17:61 ~ 64.

  3. Crystal structure transformation in potassium acrylate

    Science.gov (United States)

    Pai Verneker, V. R.; Vasanthakumari, R.

    1983-10-01

    Potassium acrylate undergoes a reversible phase transformation around 335°K with an activation energy of 133 kcal/mole. Differential scanning calorimetry and high temperature X-ray powder diffraction techniques have been used to probe this phenomenon.

  4. Characterization of electron beam cured epoxy acrylate

    International Nuclear Information System (INIS)

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  5. Resistance of acrylic vessel to gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  6. Rapid Output Growth of Special Acrylic Esters

    Institute of Scientific and Technical Information of China (English)

    Wang Lianzhi

    2007-01-01

    @@ Acrylic esters are usually classified into general-purpose varieties and special varieties. The production and application of general-purpose varieties is already quite matured in the world and their output growth tends to be flat. Owing to the development of coatings, electronics, automobiles,textiles, printing and construction sectors, especially the application of radiation curing technology in various sectors, special acrylic esters have developed rapidly.

  7. Gel time of calcium acrylate grouting material.

    Science.gov (United States)

    Han, Tong-Chun

    2004-08-01

    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerization reaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reaction kinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time of calcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and an example is provided to verify the proposed formula. PMID:15236477

  8. Gel time of calcium acrylate grouting material

    Institute of Scientific and Technical Information of China (English)

    韩同春

    2004-01-01

    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerization reaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reaction kinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time of calcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and an example is provided to verify the proposed formula.

  9. Gel time of calcium acrylate grouting material

    Institute of Scientific and Technical Information of China (English)

    韩同春

    2004-01-01

    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerizationreaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reactionkinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time ofcalcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and anexample is provided to verify the proposed formula.

  10. Intraocular lymphoma after cardiac transplantation: Magnetic resonance imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yi Kyung; Kim, Hyung Jin; Woo, Kyung In; Kim, Yoon Duck [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    We report a case of intraocular lymphoma in a 65-year-old man, 15 months after cardiac transplantation. On Magnetic Resonance (MR) images, the iris and the anterior chamber of the right eye were found to be involved with an enhancing soft-tissue lesion. To our knowledge, this is the first case of post-transplantation intraocular lymphoma evaluated with MR imaging.

  11. Surface gravity-wave lensing.

    Science.gov (United States)

    Elandt, Ryan B; Shakeri, Mostafa; Alam, Mohammad-Reza

    2014-02-01

    Here we show that a nonlinear resonance between oceanic surface waves caused by small seabed features (the so-called Bragg resonance) can be utilized to create the equivalent of lenses and curved mirrors for surface gravity waves. Such gravity wave lenses, which are merely small changes to the seafloor topography and therefore are surface noninvasive, can focus or defocus the energy of incident waves toward or away from any desired focal point. We further show that for a broadband incident wave spectrum (i.e., a wave group composed of a multitude of different-frequency waves), a polychromatic topography (occupying no more than the area required for a monochromatic lens) can achieve a broadband lensing effect. Gravity wave lenses can be utilized to create localized high-energy wave zones (e.g., for wave energy harvesting or creating artificial surf zones) as well as to disperse waves in order to create protected areas (e.g., harbors or areas near important offshore facilities). In reverse, lensing of oceanic waves may be caused by natural seabed features and may explain the frequent appearance of very high amplitude waves in certain bodies of water. PMID:25353576

  12. Gravitational Lensing by Burkert Halos

    CERN Document Server

    Park, Y; Park, Yousin; Ferguson, Henry C.

    2003-01-01

    We investigate the gravitational lensing properties of dark matter halos with Burkert profiles. We derive an analytic expression for the lens equation and use it to compute the magnification, impact parameter and image separations for strong lensing. For the scaling relation that provides the best fits to spiral-galaxy rotation curve data, Burkert halos will not produce strong lensing, even if this scaling relation extends up to masses of galaxy clusters. Tests of a simple model of an exponential stellar disk superimposed on a Burkert-profile halo demonstrate that strong lensing is unlikely without an additional concentration of mass in the galaxy center (e.g. a bulge). The fact that most strong lenses on galactic scales are elliptical galaxies suggests that a strong central concentration of baryons is required to produce image splitting. This solution is less attractive for clusters of galaxies, which are generally considered to be dark-matter dominated even at small radii. There are three possible implicati...

  13. Cosmology with weak lensing surveys.

    Science.gov (United States)

    Munshi, Dipak; Valageas, Patrick

    2005-12-15

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening mass. Since the lensing effects arise from deflections of the light rays due to fluctuations of the gravitational potential, they can be directly related to the underlying density field of the large-scale structures. Weak gravitational surveys are complementary to both galaxy surveys and cosmic microwave background observations as they probe unbiased nonlinear matter power spectra at medium redshift. Ongoing CMBR experiments such as WMAP and a future Planck satellite mission will measure the standard cosmological parameters with unprecedented accuracy. The focus of attention will then shift to understanding the nature of dark matter and vacuum energy: several recent studies suggest that lensing is the best method for constraining the dark energy equation of state. During the next 5 year period, ongoing and future weak lensing surveys such as the Joint Dark Energy Mission (JDEM; e.g. SNAP) or the Large-aperture Synoptic Survey Telescope will play a major role in advancing our understanding of the universe in this direction. In this review article, we describe various aspects of probing the matter power spectrum and the bi-spectrum and other related statistics with weak lensing surveys. This can be used to probe the background dynamics of the universe as well as the nature of dark matter and dark energy. PMID:16286284

  14. Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens

    Science.gov (United States)

    Chang, Daniel H

    2016-01-01

    Purpose The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses. Methods In this retrospective–prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50–81 years) who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00) were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft), intermediate (70–80 cm), and near (35–40 cm) under photopic (85 cd/m2) and mesopic (3 cd/m2) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. Results At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night. Conclusion Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction. PMID:27536061

  15. The M31 pixel lensing plan campaign: MACHO lensing and self-lensing signals

    Energy Technology Data Exchange (ETDEWEB)

    Calchi Novati, S.; Scarpetta, G. [Istituto Internazionale per gli Alti Studi Scientifici (IIASS), Via Pellegrino 19, I-84019 Vietri Sul Mare (Italy); Bozza, V. [Dipartimento di Fisica E. R. Caianiello, Università di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano (Italy); Bruni, I.; Gualandi, R. [INAF, Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Dall' Ora, M. [INAF, Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); De Paolis, F.; Ingrosso, G.; Nucita, A.; Strafella, F. [Dipartimento di Matematica e Fisica E. De Giorgi, Università del Salento, CP 193, I-73100 Lecce (Italy); Dominik, M. [SUPA, University of St Andrews, School of Physics and Astronomy, North Haugh, St Andrews, KY16 9SS (United Kingdom); Jetzer, Ph. [Institute for Theoretical Physics, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland); Mancini, L. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Safonova, M.; Subramaniam, A. [Indian Institute of Astrophysics, Bangalore 560 034 (India); Sereno, M. [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Gould, A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Collaboration: PLAN Collaboration

    2014-03-10

    We present the final analysis of the observational campaign carried out by the PLAN (Pixel Lensing Andromeda) collaboration to detect a dark matter signal in form of MACHOs through the microlensing effect. The campaign consists of about 1 month/year observations carried out over 4 years (2007-2010) at the 1.5 m Cassini telescope in Loiano (Astronomical Observatory of BOLOGNA, OAB) plus 10 days of data taken in 2010 at the 2 m Himalayan Chandra Telescope monitoring the central part of M31 (two fields of about 13' × 12.'6). We establish a fully automated pipeline for the search and the characterization of microlensing flux variations. As a result, we detect three microlensing candidates. We evaluate the expected signal through a full Monte Carlo simulation of the experiment completed by an analysis of the detection efficiency of our pipeline. We consider both 'self lensing' and 'MACHO lensing' lens populations, given by M31 stars and dark matter halo MACHOs, in M31 and the Milky Way, respectively. The total number of events is consistent with the expected self-lensing rate. Specifically, we evaluate an expected signal of about two self-lensing events. As for MACHO lensing, for full 0.5(10{sup –2}) M {sub ☉} MACHO halos, our prediction is for about four (seven) events. The comparatively small number of expected MACHO versus self-lensing events, together with the small number statistics at our disposal, do not enable us to put strong constraints on that population. Rather, the hypothesis, suggested by a previous analysis, on the MACHO nature of OAB-07-N2, one of the microlensing candidates, translates into a sizeable lower limit for the halo mass fraction in form of the would-be MACHO population, f, of about 15% for 0.5 M {sub ☉} MACHOs.

  16. How to measure intraocular pressure: applanation tonometry

    Directory of Open Access Journals (Sweden)

    Nick Astbury

    2012-01-01

    Full Text Available Unless there is a contraindication (e.g. trauma or corneal ulcer, all adults attending an eye unit should have their intraocular pressure (IOP measured. Many people with glaucoma have no symptoms and do not know they have the condition. All children who have had cataract surgery should also have their IOP measured at every follow-up visit, if possible. Finding glaucoma early allows treatment to be given which will preserve sight. Although elevated IOP is not the only sign of glaucoma, measuring it is simple and quick to do. Applanation tonometry, using a Goldmann tonometer at a slit lamp, is the preferred method (the ‘gold standard’.

  17. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    Directory of Open Access Journals (Sweden)

    Elena Bonafonte Marquez

    2015-01-01

    Full Text Available We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for it could be the only sign of secondary glaucoma.

  18. Implantable intraocular pressure monitoring systems: Design considerations

    KAUST Repository

    Arsalan, Muhammad

    2013-12-01

    Design considerations and limitations of implantable Intraocular Pressure Monitoring (IOPM) systems are presented in this paper. Detailed comparison with the state of the art is performed to highlight the benefits and challenges of the proposed design. The system-on-chip, presented here, is battery free and harvests energy from incoming RF signals. This low-cost design, in standard CMOS process, does not require any external components or bond wires to function. This paper provides useful insights to the designers of implantable wireless sensors in terms of design choices and associated tradeoffs. © 2013 IEEE.

  19. Lensing smoothing of BAO wiggles

    CERN Document Server

    Di Dio, Enea

    2016-01-01

    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.

  20. Cosmology from weak lensing of CMB

    CERN Document Server

    Namikawa, Toshiya

    2014-01-01

    The weak lensing effect on the cosmic microwave background (CMB) induces distortions in spatial pattern of CMB anisotropies, and statistical properties of CMB anisotropies become a weakly non-Gaussian field. We first summarize the weak lensing effect on the CMB (CMB lensing) in the presence of scalar, vector and tensor perturbations. Then we focus on the lensing effect on CMB statistics and methods to estimate deflection angles and their power spectrum. We end by summarizing recent observational progress and future prospect.

  1. Design of spherical symmetric gradient index lenses

    OpenAIRE

    Miñano Dominguez, Juan Carlos; Grabovičkić, Dejan; Benitez Gimenez, Pablo; Gonzalez Lopez, Juan Carlos; Santamaria Galdon, Maria Asuncion

    2012-01-01

    Spherical symmetric refractive index distributions also known as Gradient Index lenses such as the Maxwell-Fish-Eye (MFE), the Luneburg or the Eaton lenses have always played an important role in Optics. The recent development of the technique called Transformation Optics has renewed the interest in these gradient index lenses. For instance, Perfect Imaging within the Wave Optics framework has recently been proved using the MFE distribution. We review here the design problem of these lenses, ...

  2. Lithographically fabricated magnifying Maxwell fisheye lenses

    CERN Document Server

    Smolyaninova, V N; Jensen, C; Johnson, A; Schaefer, D; Smolyaninov, I I

    2015-01-01

    Recently suggested transformation optics-based magnifying Maxwell fisheye lenses, which are made of two half-lenses of different radii, has been fabricated and characterized. The lens action is based on control of polarization-dependent effective refractive index in a lithographically formed tapered waveguide. We have studied wavelength and polarization dependent performance of the lenses.

  3. In vitro and in vivo evaluation of novel implantation technology in hydrogel contact lenses for controlled drug delivery.

    Science.gov (United States)

    Maulvi, Furqan A; Lakdawala, Dhara H; Shaikh, Anjum A; Desai, Ankita R; Choksi, Harsh H; Vaidya, Rutvi J; Ranch, Ketan M; Koli, Akshay R; Vyas, Bhavin A; Shah, Dinesh O

    2016-03-28

    Glaucoma is commonly treated using eye drops, which is highly inefficient due to rapid clearance (low residence time) from ocular surface. Contact lenses are ideally suited for controlled drug delivery to cornea, but incorporation of any drug loaded particulate system (formulation) affect the optical and physical property of contact lenses. The objective of the present work was to implant timolol maleate (TM) loaded ethyl cellulose nanoparticle-laden ring in hydrogel contact lenses that could provide controlled drug delivery at therapeutic rates without compromising critical lens properties. TM-implant lenses were developed, by dispersing TM encapsulated ethyl cellulose nanoparticles in acrylate hydrogel (fabricated as ring implant) and implanted the same in hydrogel contact lenses (sandwich system). The TM-ethyl cellulose nanoparticles were prepared by double emulsion method at different ratios of TM to ethyl cellulose. The X-ray diffraction studies revealed the transformation of TM to amorphous state. In vitro release kinetic data showed sustained drug release within the therapeutic window for 168h (NP 1:3 batch) with 150μg loading. Cytotoxicity and ocular irritation study demonstrated the safety of TM-implant contact lenses. In vivo pharmacokinetic studies in rabbit tear fluid showed significant increase in mean residence time (MRT) and area under curve (AUC), with TM-implant contact lenses in comparison to eye drop therapy. In vivo pharmacodynamic data in rabbit model showed sustained reduction in intra ocular pressure for 192h. The study demonstrated the promising potential of implantation technology to treat glaucoma using contact lenses, and could serve as a platform for other ocular diseases.

  4. N-body lensed CMB maps: lensing extraction and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Antolini, Claudia; Martinelli, Matteo; Baccigalupi, Carlo [SISSA, Via Bonomea 265, Trieste, I-34136 (Italy); Fantaye, Yabebal [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, Oslo, N-0315 (Norway); Carbone, Carmelita, E-mail: claudia.antolini@sissa.it, E-mail: y.t.fantaye@astro.uio.no, E-mail: mmartin@sissa.it, E-mail: carmelita.carbone@brera.inaf.it, E-mail: bacci@sissa.it [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, Merate, I-23807 (Italy)

    2014-02-01

    We reconstruct shear maps and angular power spectra from simulated weakly lensed total intensity (TT) and polarised (EB) maps of the Cosmic Microwave Background (CMB) anisotropies, obtained using Born approximated ray-tracing through the N-body simulated Cold Dark Matter (CDM) structures in the Millennium Simulations (MS). We compare the recovered signal with the ΛCDM prediction, on the whole interval of angular scales which is allowed by the finite box size, extending from the degree scale to the arcminute, by applying a quadratic estimator in the flat sky limit; we consider PRISM-like instrumental specification for future generation CMB satellites, corresponding to arcminute angular resolution of 3.2' and sensitivity of 2.43 μK-arcmin. The noise contribution in the simulations closely follows the estimator prediction, becoming dominated by limits in the angular resolution for the EB signal, at ℓ ≅ 1500. The recovered signal shows no visible departure from predictions of the weak lensing power within uncertainties, when considering TT and EB data singularly. In particular, the reconstruction precision reaches the level of a few percent in bins with Δℓ ≅ 100 in the angular multiple interval 1000∼<ℓ∼<2000 for T, and about 10% for EB. Within the adopted specifications, polarisation data do represent a significant contribution to the lensing shear, which appear to faithfully trace the underlying N-body structure down to the smallest angular scales achievable with the present setup, validating at the same time the latter with respect to semi-analytical predictions from ΛCDM cosmology at the level of CMB lensing statistics. This work demonstrates the feasibility of CMB lensing studies based on large scale simulations of cosmological structure formation in the context of the current and future high resolution and sensitivity CMB experiment.

  5. Fabrication of nanoscale electrostatic lenses

    NARCIS (Netherlands)

    Sinno, I.; Sanz-Velasco, A.; Kang, S.; Jansen, H.; Olsson, E.; Enoksson, P.; Svensson, K.

    2010-01-01

    The fabrication of cylindrical multi-element electrostatic lenses at the nanoscale presents a challenge; they are high-aspect-ratio structures that should be rotationally symmetric, well aligned and freestanding, with smooth edges and flat, clean surfaces. In this paper, we present the fabrication r

  6. Irlen Lenses and Reading Difficulties.

    Science.gov (United States)

    Hoyt, Creig S.

    1990-01-01

    The article reviews three studies (EC 600 064-066) evaluating the effectiveness of using Irlen tinted lenses with reading-disabled persons. The studies are individually critiqued, and recommendations are offered concerning the methodology of further research. Stressed is the need to determine whether a specific syndrome of scotopic sensitivity…

  7. Gravitational Lensing of Supernova Neutrinos

    OpenAIRE

    Mena Requejo, Olga; Mocioiu, Irina; Quigg, Chris

    2006-01-01

    The black hole at the center of the galaxy is a powerful lens for supernova neutrinos. In the very special circumstance of a supernova near the extended line of sight from Earth to the galactic center, lensing could dramatically enhance the neutrino flux at Earth and stretch the neutrino pulse.

  8. Optics Demonstrations Using Cylindrical Lenses

    Science.gov (United States)

    Ivanov, Dragia; Nikolov, Stefan

    2015-01-01

    In this paper we consider the main properties of cylindrical lenses and propose several demonstrational experiments that can be performed with them. Specifically we use simple glasses full of water to demonstrate some basic geometrical optics principles and phenomena. We also present some less standard experiments that can be performed with such…

  9. Advantages of toric scleral lenses.

    NARCIS (Netherlands)

    Visser, E.S.; Visser, R.; Lier, H.J.J. van

    2006-01-01

    PURPOSE: The purpose of this study was to investigate whether back surface toric scleral lenses stabilized (i.e., returned to their original position after rotation) and how long the return times were. Return time was studied in relation with actual wearing time and comfort; moreover, the performanc

  10. Effect of a tight necktie on intraocular pressure

    Directory of Open Access Journals (Sweden)

    Božić Marija

    2012-01-01

    Full Text Available Introduction. Any factor causing constriction of the neck may lead to an increase in intraocular pressure. A tight necktie may result in increasing intraocular pressure, which could lead to an erroneous diagnosis and treatment of ocular hypertension or even glaucoma. This study was aimed at evaluating the effect of a tight necktie on intraocular pressure measurement using Goldmann applanation tonometry. Material and Methods. This study included forty eyes of 20 patients with primary open angle glaucoma and 20 healthy controls (all male. Intraocular pressure was measured without a necktie, 3 minutes after placing a tight necktie and 3 minutes after loosening it. Student’s t-test was used to analyze the data between two groups. The intraocular pressure measurements were subjected to paired t - test. The value p < 0.05 was considered statistically significant. A possible correlation between the age of subjects and intraocular pressure values was analyzed using linear regression (Pearson′. Results. A statistically significant difference was found in intraocular pressure readings in all three measurements between two tested groups (p<0.05. When analyzed within groups, statistical significance in intraocular pressure readings was found after loosening the necktie (<0.05. No correlation between the age of subjects and increased intraocular pressure was found in either tested group of subjects after the necktie had been tightened (r2=0.006, p=0.70 for primary open angle patients, r2=0.07, p=0.22 for healthy controls. Conclusion. Wearing a tight necktie for a limited period of time during the day could be considered as a possible risk factor for glaucoma development.

  11. 3D printed diffractive terahertz lenses.

    Science.gov (United States)

    Furlan, Walter D; Ferrando, Vicente; Monsoriu, Juan A; Zagrajek, Przemysław; Czerwińska, Elżbieta; Szustakowski, Mieczysław

    2016-04-15

    A 3D printer was used to realize custom-made diffractive THz lenses. After testing several materials, phase binary lenses with periodic and aperiodic radial profiles were designed and constructed in polyamide material to work at 0.625 THz. The nonconventional focusing properties of such lenses were assessed by computing and measuring their axial point spread function (PSF). Our results demonstrate that inexpensive 3D printed THz diffractive lenses can be reliably used in focusing and imaging THz systems. Diffractive THz lenses with unprecedented features, such as extended depth of focus or bifocalization, have been demonstrated. PMID:27082335

  12. Accelerated 20-year sunlight exposure simulation of a photochromic foldable intraocular lens in a rabbit model

    Science.gov (United States)

    Werner, Liliana; Abdel-Aziz, Salwa; Peck, Carolee Cutler; Monson, Bryan; Espandar, Ladan; Zaugg, Brian; Stringham, Jack; Wilcox, Chris; Mamalis, Nick

    2011-01-01

    PURPOSE To assess the long-term biocompatibility and photochromic stability of a new photochromic hydrophobic acrylic intraocular lens (IOL) under extended ultraviolet (UV) light exposure. SETTING John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN Experimental study. METHODS A Matrix Aurium photochromic IOL was implanted in right eyes and a Matrix Acrylic IOL without photochromic properties (n = 6) or a single-piece AcrySof Natural SN60AT (N = 5) IOL in left eyes of 11 New Zealand rabbits. The rabbits were exposed to a UV light source of 5 mW/cm2 for 3 hours during every 8-hour period, equivalent to 9 hours a day, and followed for up to 12 months. The photochromic changes were evaluated during slitlamp examination by shining a penlight UV source in the right eye. After the rabbits were humanely killed and the eyes enucleated, study and control IOLs were explanted and evaluated in vitro on UV exposure and studied histopathologically. RESULTS The photochromic IOL was as biocompatible as the control IOLs after 12 months under conditions simulating at least 20 years of UV exposure. In vitro evaluation confirmed the retained optical properties, with photochromic changes observed within 7 seconds of UV exposure. The rabbit eyes had clinical and histopathological changes expected in this model with a 12-month follow-up. CONCLUSIONS The new photochromic IOL turned yellow only on exposure to UV light. The photochromic changes were reversible, reproducible, and stable over time. The IOL was biocompatible with up to 12 months of accelerated UV exposure simulation. PMID:21241924

  13. 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.

  14. MicroRNA profiling in intraocular medulloepitheliomas.

    Directory of Open Access Journals (Sweden)

    Deepak P Edward

    Full Text Available To study the differential expression of microRNA (miRNA profiles between intraocular medulloepithelioma (ME and normal control tissue (CT.Total RNA was extracted from formalin fixed paraffin embedded (FFPE intraocular ME (n=7 and from age matched ciliary body controls (n=8. The clinical history and phenotype was recorded. MiRNA profiles were determined using the Affymetrix GeneChip miRNA Arrays analyzed using expression console 1.3 software. Validation of significantly dysregulated miRNA was confirmed by quantitative real-time PCR. The web-based DNA Intelligent Analysis (DIANA-miRPath v2.0 was used to perform enrichment analysis of differentially expressed (DE miRNA gene targets in Kyoto Encyclopedia of Genes and Genomes (KEGG pathway.The pathologic evaluation revealed one benign (benign non-teratoid, n=1 and six malignant tumors (malignant teratoid, n=2; malignant non-teratoid, n = 4. A total of 88 miRNAs were upregulated and 43 miRNAs were downregulated significantly (P<0.05 in the tumor specimens. Many of these significantly dysregulated miRNAs were known to play various roles in carcinogenesis and tumor behavior. RT-PCR validated three significantly upregulated miRNAs and three significantly downregulated miRNAs namely miR-217, miR-216a, miR-216b, miR-146a, miR-509-3p and miR-211. Many DE miRNAs that were significant in ME tumors showed dysregulation in retinoblastoma, glioblastoma, and precursor, normal and reactive human cartilage. Enriched pathway analysis suggested a significant association of upregulated miRNAs with 15 pathways involved in prion disease and several types of cancer. The pathways involving significantly downregulated miRNAs included the toll-like receptor (TLR (p<4.36E-16 and Nuclear Factor kappa B (NF-κB signaling pathways (p<9.00E-06.We report significantly dysregulated miRNAs in intraocular ME tumors, which exhibited abnormal profiles in other cancers as well such as retinoblastoma and glioblastoma. Pathway analysis

  15. 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

  16. Primary orbital neuroblastoma with intraocular extension

    Directory of Open Access Journals (Sweden)

    Muthukrishnan Vallinayagam

    2015-01-01

    Full Text Available Neuroblastoma is an undifferentiated malignancy of primitive neuroblasts. Neuroblastoma is among the most common solid tumors of childhood. Orbital neuroblastoma is typically a metastatic tumor. In this case report, we describe a 2-year-old child with a rapidly progressing orbital tumor. Computed tomography revealed an orbital mass lesion with extraocular and intraocular components. An incisional biopsy was done, and a histopathological examination showed features suggestive of neuroblastoma. Systemic workup including ultrasonography of the abdomen, chest roentgenogram, whole body computed tomography, and bone scintigraphy showed no evidence of systemic involvement. The diagnosis of primary orbital neuroblastoma was made, and the child was subjected to chemotherapy followed by rapid melting of the tumor. Neuroblastoma should be considered in the differential diagnosis of childhood orbital tumors.

  17. Occupational fingertip eczema from acrylates in a manicurist

    OpenAIRE

    Denitza Zheleva; Razvigor Darlenski

    2015-01-01

    Occupational hand eczema due to acrylates present in the workplace is a disease frequently reported among dentists, printers, and fiberglass workers. Acrylate monomers are used in the production of a great variety of polymers, including nail cosmetics. Our case report demonstrates a rare clinical presentations of allergic contact dermatitis from acrylic nails. Our patient was working as a manicurist and the diagnostic analyses revealed sensitation to some of the (meth) acrylate compounds of h...

  18. Intraocular pressure in Japanese diabetic patients

    Directory of Open Access Journals (Sweden)

    Matsuoka M

    2012-07-01

    Full Text Available Masato Matsuoka,1 Nahoko Ogata,2 Kayako Matsuyama,1 Tadanobu Yoshikawa,1 Kanji Takahashi31Department of Ophthalmology, Kansai Medical University, Takii Hospital, Osaka, 2Department of Ophthalmology, Nara Medical University, Nara, 3Department of Ophthalmology, Kansai Medical University, Hirakata Hospital, Osaka, JapanBackground: To determine whether the intraocular pressure (IOP in diabetic patients is significantly different from that in nondiabetic patients.Methods: The medical records of all patients who were initially examined in the Department of Ophthalmology, Kansai Medical University, Takii Hospital were reviewed. At the initial examination, patients had a detailed interview and underwent a comprehensive ophthalmic examinations. All patients were over 20 years of age and did not have glaucoma.Results: A total of 703 patients were evaluated. The mean (±standard error IOP of the diabetic patients was 15.5 ± 0.2 mmHg (n = 206, and was significantly higher than the 14.0 ± 0.1 mmHg (n = 497 in the nondiabetic patients (P < 0.0001. The IOP was negatively correlated with age (r = –0.202; P = 0.024 in the diabetic patients and was weakly but significantly correlated with the glycosylated hemoglobin (HbA1c level (r = 0.240; P = 0.015 in the group with diabetic retinopathy.Conclusion: The significantly higher IOP in diabetic patients and positive correlation of IOP with HbA1c levels in patients with diabetic retinopathy indicate that IOP in diabetic patients is higher, especially in those with poor control of diabetes.Keywords: diabetes mellitus, diabetic retinopathy, intraocular pressure, open-angle glaucoma

  19. Computational modeling of intraocular gas dynamics

    Science.gov (United States)

    Noohi, P.; Abdekhodaie, M. J.; Cheng, Y. L.

    2015-12-01

    The purpose of this study was to develop a computational model to simulate the dynamics of intraocular gas behavior in pneumatic retinopexy (PR) procedure. The presented model predicted intraocular gas volume at any time and determined the tolerance angle within which a patient can maneuver and still gas completely covers the tear(s). Computational fluid dynamics calculations were conducted to describe PR procedure. The geometrical model was constructed based on the rabbit and human eye dimensions. SF6 in the form of pure and diluted with air was considered as the injected gas. The presented results indicated that the composition of the injected gas affected the gas absorption rate and gas volume. After injection of pure SF6, the bubble expanded to 2.3 times of its initial volume during the first 23 h, but when diluted SF6 was used, no significant expansion was observed. Also, head positioning for the treatment of retinal tear influenced the rate of gas absorption. Moreover, the determined tolerance angle depended on the bubble and tear size. More bubble expansion and smaller retinal tear caused greater tolerance angle. For example, after 23 h, for the tear size of 2 mm the tolerance angle of using pure SF6 is 1.4 times more than that of using diluted SF6 with 80% air. Composition of the injected gas and conditions of the tear in PR may dramatically affect the gas absorption rate and gas volume. Quantifying these effects helps to predict the tolerance angle and improve treatment efficiency.

  20. Concepts for stereoselective acrylate insertion

    KAUST Repository

    Neuwald, Boris

    2013-01-23

    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  1. Assessing the effect of laser beam width on quantitative evaluation of optical properties of intraocular lens implants

    Science.gov (United States)

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

    2014-05-01

    The design and manufacture of intraocular lenses (IOLs) depend upon the identification and quantitative preclinical evaluation of key optical properties and environmental parameters. The confocal laser method (CLM) is a new technique for measuring IOL optical properties, such as dioptric power, optical quality, refractive index, and geometrical parameters. In comparison to competing systems, the CLM utilizes a fiber-optic confocal laser design that significantly improves the resolution, accuracy, and repeatability of optical measurements. Here, we investigate the impact of changing the beam diameter on the CLM platform for the evaluation of IOL dioptric powers. Due to the Gaussian intensity profile of the CLM laser beam, the changes in focal length and dioptric power associated with changes in beam diameter are well within the tolerances specified in the ISO IOL standard. These results demonstrate some of the advanced potentials of the CLM toward more effectively and quantitatively evaluating IOL optical properties.

  2. SYNTHESIS OF BIOCOMPATIBLE ACRYLIC POLYMERS HAVING ASPIRIN-MOIETIES

    Institute of Scientific and Technical Information of China (English)

    LI Fumian; GU Zhongwei; FENG Xinde(S. T. Voong)

    1983-01-01

    Several new monomers, β-(acetylsalicylyloxy)ethyl methacrylate, β-(acetylsalicylyloxy)propyl methacrylate, β-(acetylsalicylyloxy)ethyl acrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl methacrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl acrylate have been synthesized from aspirin with corresponding hydroxyalkyl or glycidyl acrylates, and then polymerized by free radical initiator.

  3. 40 CFR 721.5325 - Nickel acrylate complex.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  4. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  5. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid...

  6. 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 n...

  7. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  8. 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...

  9. 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 saccharificatio

  10. Application of Foldable Intraocular Lens in Multiple Types of Cataract

    Institute of Scientific and Technical Information of China (English)

    Songtao Yuan; Qinghuai Liu; Qing Jiang; Nanrong Yuan

    2002-01-01

    Objective: To evaluate the clinical results of implantation of foldable intraocular lens inmultiple types of cataract.Methods: This retrospective study comprised 162 eyes of 148 patients undergoingphacoemulsification and implantation of foldable intraocular lens, some of whom under-went combined pars plana vitrectomy or trabeculectomy or silicone oil removal. Theperiod of follow-up was from 3 months to 17 months.Results: There is slight reaction postoperatively in all cases. The postoperative uncorrectedvisual acuites was from 0. 05 to 1.2, patient with 0.6 or above acuity were 70.98%. Aneodymium: YAG capsulotomy was required in 5 eyes. Posterior capsule ruptured in 1eyes, and a PMMA intraocular lens was implanted in ciliary sulcus. In one eye, a lenswas removed because of recurrence of retina detachment.Conclusions: The application of foldable intraocular lens in multiple types of cataract issafe, and there is a slight postoperative reaction. less complications , and fast visualacuity recovery.

  11. Patient acceptability of the Tecnis® multifocal intraocular lens

    Directory of Open Access Journals (Sweden)

    Sood P

    2011-03-01

    Full Text Available Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anterior prolate IOL with a diffractive multifocal lens design. The design aims to minimize spherical aberration and improve range of focus. The purpose of this review is to assess patient acceptability of the Tecnis® multifocal intraocular lens.Keywords: Tecnis®, intraocular lens, multifocal, presbyopia 

  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. Intraocular Gnathostomiasis: Report of a Case and Review of Literature

    OpenAIRE

    Pillai, Gopal S.; Kumar, Anil; Radhakrishnan, Natasha; Maniyelil, Jayasree; Shafi, Tufela; Dinesh, Kavitha R.; Karim, Shamsul

    2012-01-01

    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...

  14. Metabolic Syndrome as a Risk Factor for Elevated Intraocular Pressure

    OpenAIRE

    Sahinoglu-Keskek, Nedime; Keskek, Sakir Ozgur; Cevher, Selim; Kirim, Sinan; Kayiklik, Asim; Ortoglu, Gulay; Saler, Tayyibe

    2014-01-01

    Objective: The aim of this study was to investigate the association between intraocular pressure and metabolic syndrome by comparing central corneal thicknesses. Methods: One hundred sixty-two subjects were enrolled in this cross-sectional study, with 89 subjects in a metabolic syndrome group and 73 subjects in a control group. Ophthalmological examinations, including intraocular pressure and central corneal thickness measurements, were performed on each subject. Serum fasting glucose, trigly...

  15. Patient acceptability of the Tecnis® multifocal intraocular lens

    OpenAIRE

    Woodward, Maria; Sood,Priyanka

    2011-01-01

    Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL) designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anter...

  16. New case of gravitational lensing

    Energy Technology Data Exchange (ETDEWEB)

    Surdej, J.; Swings, J.-P.; Magain, P.; Borgeest, U.; Kayser, R.; Refsdal, S.; Courvoisier, T.J.-L.; Kellermann, K.I.; Kuehr, H.

    1987-10-22

    The authors report a brief description of a gravitational lens system UM673 = Q0142 - 100 = PHL3703. It consists of two images, A and B, separated by 2.2 arc s at a redshift zsub(q) = 2.719. The lensing galaxy has also been found. It lies very near the line connecting the two QSO (quasi-stellar objects) images, approx. 0.8 arc s from the fainter one. Application of gravitational optometry to this system leads to a value Msub(o) or approx. = 2.4 x 10/sup 11/ M solar masses for the mass of the lensing galaxy and to ..delta..t approx. 7 weeks for the most likely travel-time difference between the two light paths to the QSO.

  17. Gravitational Lensing - Einstein's Unfinished Symphony

    CERN Document Server

    Treu, Tommaso

    2014-01-01

    Gravitational lensing - the deflection of light rays by gravitating matter - has become a major tool in the armoury of the modern cosmologist. Proposed nearly a hundred years ago as a key feature of Einstein's theory of General Relativity, we trace the historical development since its verification at a solar eclipse in 1919. Einstein was apparently cautious about its practical utility and the subject lay dormant observationally for nearly 60 years. Nonetheless there has been rapid progress over the past twenty years. The technique allows astronomers to chart the distribution of dark matter on large and small scales thereby testing predictions of the standard cosmological model which assumes dark matter comprises a massive weakly-interacting particle. By measuring distances and tracing the growth of dark matter structure over cosmic time, gravitational lensing also holds great promise in determining whether the dark energy, postulated to explain the accelerated cosmic expansion, is a vacuum energy density or a...

  18. Extinction Curves of Lensing Galaxies

    Science.gov (United States)

    Elíasdóttir, Árdís

    2006-09-01

    Dust extinction causes light from distant sources to be dimmed on itsway to the observer. In cosmological studies, such as SN Ia studies,it is of great importance that the effects of dust extinction becorrectly accounted for. However, although dust properties, andhence extinction, are expected to vary with redshift, not very muchis known about the extinction properties of high redshift galaxies.This is because the methods traditionally used to study extinctioncurves are only applicable for the most nearby galaxies. Studyinggravitationally lensed quasars is an emerging method of studying thedust extinction of high redshift galaxies. I will present an ESO VLTstudy of 10 such lensing galaxies, with redshifts up to 1. The 10systems display varying amount and type of extinction, with thedoubly imaged quasar B1152+199 showing the greatest extinction with A(V)=2.4 and R_V=2.1 for a Galactic type extinction law.

  19. Visual Performance after Bilateral Implantation of a Four-Haptic Diffractive Toric Multifocal Intraocular Lens in High Myopes.

    Science.gov (United States)

    Chang, John S M; Chan, Vincent K C; Ng, Jack C M; Law, Antony K P

    2016-01-01

    Background. The vision with diffractive toric multifocal intraocular lenses after cataract surgery in long eyes has not been studied previously. Objectives. To report visual performance after bilateral implantation of a diffractive toric multifocal intraocular lens in high myopes. Methods. Prospective, observational case series to include patients with axial length of ≥26 mm and corneal astigmatism of >1 dioptre who underwent bilateral AT LISA 909M implantation. Postoperative examinations included photopic and mesopic distance, intermediate, and near visual acuity; photopic contrast sensitivity; visual symptoms (0-5); satisfaction (1-5); and spectacle independence rate. Results. Twenty-eight eyes (14 patients) were included. Postoperatively, mean photopic monocular uncorrected distance, intermediate, and near visual acuities (logMAR) were 0.12 ± 0.20 (standard deviation), 0.24 ± 0.16, and 0.29 ± 0.21, respectively. Corresponding binocular values were -0.01 ± 0.14, 0.13 ± 0.12, and 0.20 ± 0.19, respectively. One eye (4%) had one-line loss in vision. Under mesopic condition, intermediate vision and near vision decreased significantly (all P ≤ 0.001). Contrast sensitivity at all spatial frequencies did not improve significantly under binocular condition (all P > 0.05). Median scores for halos, night glare, starbursts, and satisfaction were 0.50, 0.00, 0.00, and 4.25, respectively. Ten patients (71%) reported complete spectacle independence. Conclusions. Bilateral implantation of the intraocular lens in high myopes appeared to be safe and achieved good visual performance and high satisfaction. PMID:27563460

  20. Visual Performance after Bilateral Implantation of a Four-Haptic Diffractive Toric Multifocal Intraocular Lens in High Myopes

    Science.gov (United States)

    Chan, Vincent K. C.

    2016-01-01

    Background. The vision with diffractive toric multifocal intraocular lenses after cataract surgery in long eyes has not been studied previously. Objectives. To report visual performance after bilateral implantation of a diffractive toric multifocal intraocular lens in high myopes. Methods. Prospective, observational case series to include patients with axial length of ≥26 mm and corneal astigmatism of >1 dioptre who underwent bilateral AT LISA 909M implantation. Postoperative examinations included photopic and mesopic distance, intermediate, and near visual acuity; photopic contrast sensitivity; visual symptoms (0–5); satisfaction (1–5); and spectacle independence rate. Results. Twenty-eight eyes (14 patients) were included. Postoperatively, mean photopic monocular uncorrected distance, intermediate, and near visual acuities (logMAR) were 0.12 ± 0.20 (standard deviation), 0.24 ± 0.16, and 0.29 ± 0.21, respectively. Corresponding binocular values were −0.01 ± 0.14, 0.13 ± 0.12, and 0.20 ± 0.19, respectively. One eye (4%) had one-line loss in vision. Under mesopic condition, intermediate vision and near vision decreased significantly (all P ≤ 0.001). Contrast sensitivity at all spatial frequencies did not improve significantly under binocular condition (all P > 0.05). Median scores for halos, night glare, starbursts, and satisfaction were 0.50, 0.00, 0.00, and 4.25, respectively. Ten patients (71%) reported complete spectacle independence. Conclusions. Bilateral implantation of the intraocular lens in high myopes appeared to be safe and achieved good visual performance and high satisfaction. PMID:27563460

  1. Visual Performance after Bilateral Implantation of a Four-Haptic Diffractive Toric Multifocal Intraocular Lens in High Myopes.

    Science.gov (United States)

    Chang, John S M; Chan, Vincent K C; Ng, Jack C M; Law, Antony K P

    2016-01-01

    Background. The vision with diffractive toric multifocal intraocular lenses after cataract surgery in long eyes has not been studied previously. Objectives. To report visual performance after bilateral implantation of a diffractive toric multifocal intraocular lens in high myopes. Methods. Prospective, observational case series to include patients with axial length of ≥26 mm and corneal astigmatism of >1 dioptre who underwent bilateral AT LISA 909M implantation. Postoperative examinations included photopic and mesopic distance, intermediate, and near visual acuity; photopic contrast sensitivity; visual symptoms (0-5); satisfaction (1-5); and spectacle independence rate. Results. Twenty-eight eyes (14 patients) were included. Postoperatively, mean photopic monocular uncorrected distance, intermediate, and near visual acuities (logMAR) were 0.12 ± 0.20 (standard deviation), 0.24 ± 0.16, and 0.29 ± 0.21, respectively. Corresponding binocular values were -0.01 ± 0.14, 0.13 ± 0.12, and 0.20 ± 0.19, respectively. One eye (4%) had one-line loss in vision. Under mesopic condition, intermediate vision and near vision decreased significantly (all P ≤ 0.001). Contrast sensitivity at all spatial frequencies did not improve significantly under binocular condition (all P > 0.05). Median scores for halos, night glare, starbursts, and satisfaction were 0.50, 0.00, 0.00, and 4.25, respectively. Ten patients (71%) reported complete spectacle independence. Conclusions. Bilateral implantation of the intraocular lens in high myopes appeared to be safe and achieved good visual performance and high satisfaction.

  2. 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...

  3. Biological performance of functionalized biomedical polymers for potential applications as intraocular lens.

    Science.gov (United States)

    Zheng, Zhiwen; Wang, Yingjun; Jiao, Yan; Zhai, Zhichen

    2016-08-01

    To study the biological performance of surface-modified biomedical polymer materials, a model of the functional mechanism of nonspecific adsorption resistance was constructed. Cell behavior on the surface and in vivo transplantation features of intraocular lens (IOL) materials, such as hydrophobic acrylic ester and polymethyl methacrylate (PMMA), were investigated. The results of cell adhesion and proliferation studies showed that the addition of hirudin can significantly resist epithelial cell adhesion, better than the pure amination process, and thereby inhibit excessive proliferation on the surface. Experiments on the eyes of rabbits indicated that the IOL surfaces with hirudin modification reduced the incidence of cell aggregation and inflammation. Combined with a study of protein-resistant layer construction with recombinant hirudin on the material surface, the mechanism of surface functionalization was determined. The biological performance indicated that nonspecific adsorption is greatly decreased due to the existence of amphiphilic ions or hydration layers, which lead to stability and long-term resistance to nonspecific adsorption. These results offer a theoretical basis for the use of traditional biomedical polymer materials in long-term clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1961-1967, 2016.

  4. Relation between intraocular pressure and size of transverse sinuses.

    Science.gov (United States)

    Kantarci, Mecit; Dane, Senol; Gumustekin, Kenan; Onbas, Omer; Alper, Fatih; Okur, Adnan; 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. PMID:15647949

  5. 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.)

  6. Uncontrolled Selling of Contact Lenses

    Directory of Open Access Journals (Sweden)

    Cem Sundu

    2015-05-01

    Full Text Available Objectives: To evaluate the opticians’ perspective about selling and applying contact lenses (CL in the provincial centre of Mersin. Materials and Methods: Twenty opticians who work in the 4 main districts in the provincial centre of Mersin were included in the study. A questionnaire form which was prepared before was filled out by the participants. Results: Seventy-eight percent of the opticians were selling CL without prescription, whereas 25% also carried out its fitting. Seventyfive percent of the participants did not get any education about contact lenses, while 65% of them were feeling themselves disqualified about CLs. Furthermore, half of the participants did not have enough knowledge about the complications associated with CL usage and 75% of them wanted to receive information about CLs. Conclusion: As a result of the questionnaire, we found out that a significant part of the participants were both selling and fitting contact lenses without prescription. We believe that auditing the opticians is as important as educating the contact lens users. (Turk J Ophthalmol 2015; 45: 102-104

  7. Gravitational Lensing: Einstein's unfinished symphony

    Science.gov (United States)

    Treu, Tommaso; Ellis, Richard S.

    2015-01-01

    Gravitational lensing - the deflection of light rays by gravitating matter - has become a major tool in the armoury of the modern cosmologist. Proposed nearly a hundred years ago as a key feature of Einstein's theory of general relativity, we trace the historical development since its verification at a solar eclipse in 1919. Einstein was apparently cautious about its practical utility and the subject lay dormant observationally for nearly 60 years. Nonetheless there has been rapid progress over the past twenty years. The technique allows astronomers to chart the distribution of dark matter on large and small scales thereby testing predictions of the standard cosmological model which assumes dark matter comprises a massive weakly-interacting particle. By measuring the distances and tracing the growth of dark matter structure over cosmic time, gravitational lensing also holds great promise in determining whether the dark energy, postulated to explain the accelerated cosmic expansion, is a vacuum energy density or a failure of general relativity on large scales. We illustrate the wide range of applications which harness the power of gravitational lensing, from searches for the earliest galaxies magnified by massive clusters to those for extrasolar planets which temporarily brighten a background star. We summarise the future prospects with dedicated ground and space-based facilities designed to exploit this remarkable physical phenomenon.

  8. Acrylic Tanks for Stunning Chemical Demonstrations

    Science.gov (United States)

    Mirholm, Alexander; Ellervik, Ulf

    2009-01-01

    We describe the use of acrylic tanks (400 x 450 x 27 mm) for visualization of chemical demonstrations in aqueous solutions. Examples of well-suited demonstrations are oscillating reactions, pH indicators, photochemical reduction of Lauth's violet, and chemoluminiscent reactions. (Contains 1 figure.)

  9. 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; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; 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; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Mazzotta, P; 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; Zonca, A

    2015-01-01

    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 ...

  10. Discovery of eight lensing clusters of galaxies

    CERN Document Server

    Liang, S M; Han, J L; Jiang, Y Y

    2013-01-01

    Clusters of galaxies have a huge mass which can act as gravitational lenses. Galaxies behind clusters can be distorted to form arcs in images by the lenses. Herein a search was done for giant lensed arcs by galaxy clusters using the SDSS data. By visually inspecting SDSS images of newly identified clusters in the SDSS DR8 and Stripe 82 data, we discover 8 strong lensing clusters together with additional 3 probable and 6 possible cases. The lensed arcs show bluer colors than the member galaxies of clusters. The masses and optical luminosities of galaxy clusters interior to the arcs are calculated, and the mass-to-light ratios are found to be in the range of a few tens of M_Solar/L_Solar, consistent with the distribution of previously known lensing clusters.

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

    Science.gov (United States)

    Mendoza-Mendieta, María Elena; Lorenzo-Mejía, Ana Aurora

    2016-01-01

    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 phacoemul-sification 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 observed in the elderly population, whereas no patients in the group with transparent IOLs had depression. PMID:27099465

  12. 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.

  13. 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 ...

  14. A Computer Program to Visualize Gravitational Lenses

    CERN Document Server

    Frutos-Alfaro, F

    2002-01-01

    Gravitational lenses are presently playing an important role in astrophysics. By means of these lenses the parameters of the deflector such as its mass, ellipticity, etc. and Hubble's constant can be determined. Using C, Xforms, Mesa and Imlib a computer program to visualize this lens effect has been developed. This program has been applied to generate sequences of images of a source object and its corresponding images. It has also been used to visually test different models of gravitational lenses.

  15. Instrumental systematics and weak gravitational lensing

    CERN Document Server

    Mandelbaum, Rachel

    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.

  16. Instrumental systematics and weak gravitational lensing

    Science.gov (United States)

    Mandelbaum, R.

    2015-05-01

    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.

  17. M31 Pixel Lensing PLAN Campaign: MACHO Lensing and Self Lensing Signals

    CERN Document Server

    Novati, S Calchi; Bruni, I; Dall'Ora, M; De Paolis, F; Dominik, M; Gualandi, R; Ingrosso, G; Jetzer, Ph; Mancini, L; Nucita, A; Safonova, M; Scarpetta, G; Sereno, M; Strafella, F; Subramaniam, A; Gould, A

    2014-01-01

    We present the final analysis of the observational campaign carried out by the PLAN (Pixel Lensing Andromeda) collaboration to detect a dark matter signal in form of MACHOs through the microlensing effect. The campaign consists of about 1 month/year observations carried out during 4 years (2007-2010) at the 1.5m Cassini telescope in Loiano ("Astronomical Observatory of BOLOGNA", OAB) plus 10 days of data taken in 2010 at the 2m Himalayan Chandra Telescope (HCT) monitoring the central part of M31 (two fields of about 13'x12.6'). We establish a fully automated pipeline for the search and the characterization of microlensing flux variations: as a result we detect 3 microlensing candidates. We evaluate the expected signal through a full Monte Carlo simulation of the experiment completed by an analysis of the detection efficiency of our pipeline. We consider both "self lensing" and "MACHO lensing" lens populations, given by M31 stars and dark matter halo MACHOs, in the M31 and the Milky Way (MW), respectively. The...

  18. Design of spherical symmetric gradient index lenses

    Science.gov (United States)

    Miñano, Juan C.; Grabovičkić, Dejan; Benítez, Pablo; González, Juan C.; Santamaría, Asunción

    2012-10-01

    Spherical symmetric refractive index distributions also known as Gradient Index lenses such as the Maxwell-Fish-Eye (MFE), the Luneburg or the Eaton lenses have always played an important role in Optics. The recent development of the technique called Transformation Optics has renewed the interest in these gradient index lenses. For instance, Perfect Imaging within the Wave Optics framework has recently been proved using the MFE distribution. We review here the design problem of these lenses, classify them in two groups (Luneburg moveable-limits and fixed-limits type), and establish a new design techniques for each type of problem.

  19. Weak Gravitational Lensing and its Cosmological Applications

    CERN Document Server

    Hoekstra, Henk

    2008-01-01

    Weak gravitational lensing is a unique probe of the dark side of the universe: it provides a direct way to map the distribution of dark matter around galaxies, clusters of galaxies and on cosmological scales. Furthermore, the measurement of lensing induced distortions of the shapes of distant galaxies is a powerful probe of dark energy. In this review we describe how lensing measurements are made and interpreted. We discuss various systematic effects that can hamper progress and how they may be overcome. We review some of the recent results in weak lensing by galaxies, galaxy clusters and cosmic shear and discuss the prospects for dark energy measurements from planned surveys.

  20. Clinical Application of Aspheric Intraocular Lens%浅谈非球面人工晶状体的临床应用

    Institute of Scientific and Technical Information of China (English)

    许玉梅

    2016-01-01

    目的:通过非球面人工晶状体植入术后视功能的变化,观察治疗效果,提出治疗建议,客观评价非球面人工晶状体的临床作用。方法从眼球面像差的特性,非球面人工晶状体的设计及矫正目标,非球面人工晶状体临床应用注意事项,非球面人工晶状体的视觉质量评价等方面进行分析。结果虽然非球面人工晶状体眼术后的高阶像差低于球面人工晶状体,但其视力和对比敏感度的结果并不完全与之相对应。由于目前我们对人眼波前像差的认识还不够深入,检测仪器不够完善,各阶像差与视功能之间的关系尚需进一步的研究。结论正常瞳孔下非球面人工晶状体眼与球面人工晶状体眼相比,非球面人工晶体可以有效减少球面像差,提高部分空间频率的对比敏感度,使患者拥有更好地视觉质量,但其不能体现减少术眼后高阶像差的优势。%Objective Through the changes of visual function after implantation of aspheric intraocular lens(IOL)observed treatment effect,treatment recommendations,and objective evaluation of non spherical intraocular lens(IOL)clinical effect. MethodsFrom the ocular wavefront aberration characteristics,the design of aspheric intraocular lens and correctional goal and clinical application of aspheric intraocular lenses note,aspheric intraocular lens visual quality evaluation were analyzed.Results Although the high order aberrations of the patients with non spherical intraocular lens were lower than that of the spherical intraocular lens,the visual acuity and contrast sensitivity were not completely corresponding with the results. Because at present we of wavefront aberration of understanding is not deep enough,detection equipment is not perfect,aberration and depending on the relationship between function stil need to further study.Conclusion With normal pupil non compared to spherical intraocular lens eyes and spherical

  1. cluster-lensing: Tools for calculating properties and weak lensing profiles of galaxy clusters

    Science.gov (United States)

    Ford, Jes

    2016-05-01

    The cluster-lensing package calculates properties and weak lensing profiles of galaxy clusters. Implemented in Python, it includes cluster mass-richness and mass-concentration scaling relations, and NFW halo profiles for weak lensing shear, the differential surface mass density ΔΣ(r), and for magnification, Σ(r). Optionally the calculation will include the effects of cluster miscentering offsets.

  2. A study of brachytherapy for intraocular tumor

    International Nuclear Information System (INIS)

    Our purpose of this study is to perform brachytherapy for intraocular tumor. The result were as followed. 1. Eye model was determined as a 25 mm diameter sphere. Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15 mm, 17 mm and 20 mm in diameter, and 1.5 mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5 mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within ±10% and distance deviations are within 0.4 mm. Maximum error is -11.3% and 0.8 mm, respectively. 7 figs, 2 tabs, 28 refs. (Author)

  3. Avaliação da eficácia da facectomia com implante de lente intra-ocular na infância Efficacy of pediatric cataract extraction with intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Núbia Cristina de Freitas Maia

    2005-12-01

    Full Text Available OBJETIVO: Avaliar eficácia da utilização da lente intra-ocular na correção da afacia na infância, segundo a acuidade visual e alteração refracional no pós-operatório. MÉTODOS: Foram estudados trinta e três olhos de 27 crianças portadores de catarata, unilateral ou bilateral, submetidos à cirurgia de lensectomia via pars plana com implante de lente intra-ocular, associada à capsulectomia posterior primária e vitrectomia anterior. O cálculo da lente intra-ocular foi realizado com o objetivo da emetropia no pós-operatório imediato. As crianças apresentavam idades inferiores a seis anos no momento da cirurgia e foram acompanhadas em média durante 2,9 anos. Foram divididas em três grupos: crianças portadoras de catarata unilateral operadas com idade inferior a três anos (Grupo I e superior a três anos (Grupo II e grupo III formado pelas crianças portadoras de cataratas bilaterais. RESULTADOS: Acuidade visual pós-operatória obtida no último controle igual ou superior a 20/40 foi encontrada em 85% dos olhos operados. Equivalente esférico no primeiro mês pós-operatório próximo da emetropia foi obtido em 70% das crianças do grupo III e em apenas 30% do grupo I. Quanto à variação refracional pós-operatória, a miopização foi encontrada em 81,81% dos casos, sendo maior esta alteração refracional quanto menor a idade em que a criança foi submetida à cirurgia. CONCLUSÃO: Apesar da miopização pós-operatória que ocorre com o implante de lente intra-ocular na correção da afacia em crianças com menos de seis anos de idade, o resultado visual é bastante satisfatório e a correção refracional residual de fácil execução. Um seguimento pós-operatório mais prolongado há de ser necessário para o acompanhamento dos resultados a longo prazo.PURPOSE: To evaluate the efficacy of the use of intraocular lenses in the treatment of pediatric aphakia, according to postoperative visual acuity and refraction change

  4. METHACRYLATE AND ACRYLATE ALLERGY IN DENTAL STUDENTS.

    Directory of Open Access Journals (Sweden)

    Maya Lyapina

    2013-09-01

    Full Text Available A multitude of acrylic monomers is used in dentistry, and when dental personnel, patients or students of dental medicine become sensitized, it is of great importance to identify the dental ;acrylic preparations to which the sensitized individual can be exposed. Numerous studies confirm high incidence of sensitization to (meth acrylates in dentatal professionals, as well as in patients undergoing dental treatment and exposed to resin-based materials. Quite a few studies are available aiming to evaluate the incidence of sensitization in students of dental medicineThe purpose of the study is to evaluate the incidence of contact sensitization to some (meth acrylates in students of dental medicine at the time of their education, in dental professionals (dentists, nurses and attendants and in patients, the manifestation of co-reactivity.A total of 139 participants were included in the study, divided into four groups: occupationally exposed to (methacrylates and acrylic monomers dental professionals, 3-4 year-of-education students of dental medicine, 6th year–of-education students of dental medicine and patients with suspected or established sensitization to acrylates, without occupational exposure. All of them were patch-tested with methyl methacrylate (MMA, triethyleneglycol dimethacrylate (TREGDMA, ethyleneglycol dimethacrylate (EGDMA, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy phenyl]propane (bis-GMA, 2-hydroxyethyl methacrylate (2-HEMA, and tetrahidrofurfuril metacrylate. The overall sensitization rates to methacrylates in the studied population are comparative high – from 25.9% for MMA to 31.7% for TREGDMA. Significantly higher incidence of sensitization in the group of 3-4 course students compared to the one in the group of dental professionals for MMA and TREGDMA was observed. Highest was the incidence of sensitization to ethyleneglycol dimethacrylate, BIS-GMA, 2-HEMA and tetrahydrofurfuryl methacrylate in the group of patients, with

  5. 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

  6. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation.

    Science.gov (United States)

    Horiguchi, Lie; Garcia, Patricia Novita; Malavazzi, Gustavo Ricci; Allemann, Norma; Gomes, Rachel L R

    2016-01-01

    Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno.

  7. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation

    Directory of Open Access Journals (Sweden)

    Lie Horiguchi

    2016-01-01

    Full Text Available Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL using ultrasound biomicroscopy (UBM. Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6% and the ab interno in 8 eyes (53.3%. In the ab externo technique, 14 haptics were located: 4 (28.57% in the ciliary sulcus; 2 (14.28% anterior to the sulcus; and 8 (57.14% posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0% were in the ciliary sulcus, 2 (12.50% anterior to the sulcus, and 10 (75.0% posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno.

  8. The impact of multifocal intraocular lens in retinal imaging with optical coherence tomography.

    Science.gov (United States)

    Dias-Santos, Arnaldo; Costa, Lívio; Lemos, Vanessa; Anjos, Rita; Vicente, André; Ferreira, Joana; Cunha, João Paulo

    2015-02-01

    Multifocal intraocular lenses (MF IOLs) have concentric optical zones with different dioptric power, enabling patients to have good visual acuity at multiple focal points. However, several optical limitations have been attributed to this particular design. The purpose of this study is to access the effect of MF IOLs design on the accuracy of retinal optical coherence tomography (OCT). Cross-sectional study conducted at the Refractive Surgery Department of Central Lisbon Hospital Center. Twenty-three eyes of 15 patients with a diffractive MF IOL and 27 eyes of 15 patients with an aspheric monofocal IOL were included in this study. All patients underwent OCT macular scans using Heidelberg Spectralis(®). Macular thickness and volume values and image quality (Q factor) were compared between the two groups. There were no statistically significant differences between both groups regarding macular thickness or volume measurements. Retinal OCT image quality was significantly lower in the MF IOL group (p image quality. However, this fact does not seem to compromise the accuracy of spectral domain OCT retinal measurements. PMID:25381578

  9. Visual outcomes and optical quality after implantation of a diffractive multifocal toric intraocular lens

    Science.gov (United States)

    Chen, Xiangfei; Zhao, Ming; Shi, Yuhua; Yang, Liping; Lu, Yan; Huang, Zhenping

    2016-01-01

    Background: This study evaluated the visual function after implantation of a multifocal toric intraocular lenses (IOLs). Materials and Methods: This study involved 10 eyes from eight cataract patients with corneal astigmatism of 1.0 diopter (D) or higher who had received phacoemulsification with implantation of an AcrySof IQ ReSTOR Toric IOL. Six-month evaluations included visual acuity, spherical equivalent (SE), defocus curve, residual astigmatism, IOL rotation, contrast sensitivity (CS), wavefront aberrations, modulation transfer function (MTF), and patient satisfaction assessments. Results: At 6 months postoperatively, uncorrected distance visual acuity (logarithm of the minimum angle of resolution) was 0.09 ± 0.04, corrected distance visual acuity was 0.02 ± 0.11, and uncorrected near visual acuity was 0.12 ± 0.07. The mean SE was −0.095 ± 0.394 D (±0.50 D in 90%). Refractive astigmatism at the 6-month follow-up visit was significantly reduced to 0.35 ± 0.32 D from 1.50 ± 0.41 D presurgery (P 0.05). There was an increase in MTF results between preoperative and postoperative evaluations at all spatial frequencies. Conclusions: The diffractive multifocal toric IOL is able to provide a predictable astigmatic correction with apparently outstanding levels of optical quality after implantation. PMID:27221680

  10. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation

    Science.gov (United States)

    Horiguchi, Lie; Garcia, Patricia Novita; Malavazzi, Gustavo Ricci; Allemann, Norma

    2016-01-01

    Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno. PMID:27293878

  11. N-body lensed CMB maps: lensing extraction and characterization

    CERN Document Server

    Antolini, Claudia; Martinelli, Matteo; Carbone, Carmelita; Baccigalupi, Carlo

    2013-01-01

    We reconstruct shear maps and angular power spectra from simulated weakly lensed total intensity (TT) and polarised (EB) maps of the Cosmic Microwave Background (CMB) anisotropies, obtained using Born approximated ray-tracing through the N-body simulated Cold Dark Matter (CDM) structures in the Millennium Simulations (MS). We compare the recovered signal with the ${\\Lambda}$CDM prediction, on the whole interval of angular scales which is allowed by the finite box size, extending from the degree scale to the arcminute, by applying a quadratic estimator in the flat sky limit; we consider PRISM-like instrumental specification for future generation CMB satellites, corresponding to arcminute angular resolution of 3.2' and sensitivity of 2.43 ${\\mu}$K-arcmin. The noise bias in the simulations closely follows the estimator prediction, becoming dominated by limits in the angular resolution for the EB signal, at l ${\\simeq}$ 1500. The de-biased signal shows no visible departure from predictions of the weak lensing pow...

  12. The Scales of Gravitational Lensing

    CERN Document Server

    De Paolis, Francesco; Ingrosso, Gabriele; Manni, Luigi; Nucita, Achille; Strafella, Francesco

    2016-01-01

    After exactly a century since the formulation of the general theory of relativity, the phenomenon of gravitational lensing is still an extremely powerful method for investigating in astrophysics and cosmology. Indeed, it is adopted to study the distribution of the stellar component in the Milky Way, to study dark matter and dark energy on very large scales and even to discover exoplanets. Moreover, thanks to technological developments, it will allow the measure of the physical parameters (mass, angular momentum and electric charge) of supermassive black holes in the center of ours and nearby galaxies.

  13. Weak lensing by galaxy troughs

    Science.gov (United States)

    Gruen, Daniel

    2016-06-01

    Galaxy troughs, i.e. underdensities in the projected galaxy field, are a weak lensing probe of the low density Universe with high signal-to-noise ratio. I present measurements of the radial distortion of background galaxy images and the de-magnification of the CMB by troughs constructed from Dark Energy Survey and Sloan Digital Sky Survey galaxy catalogs. With high statistical significance and a relatively robust modeling, these probe gravity in regimes of density and scale difficult to access for conventional statistics.

  14. The Scales of Gravitational Lensing

    Directory of Open Access Journals (Sweden)

    Francesco De Paolis

    2016-03-01

    Full Text Available After exactly a century since the formulation of the general theory of relativity, the phenomenon of gravitational lensing is still an extremely powerful method for investigating in astrophysics and cosmology. Indeed, it is adopted to study the distribution of the stellar component in the Milky Way, to study dark matter and dark energy on very large scales and even to discover exoplanets. Moreover, thanks to technological developments, it will allow the measure of the physical parameters (mass, angular momentum and electric charge of supermassive black holes in the center of ours and nearby galaxies.

  15. Comparison of spectacle classical progressive and office progressive lenses.

    Science.gov (United States)

    Kozlík, Marek; Knollová, Libuse Nováková

    2013-04-01

    This paper elaborates on analysis of progressive spectacle lenses, to correct presbyopia, which are nowadays offered at the market. The paper describes different types of progressive lenses, their parameters, length and width of their progressive segments. It also describes degressive spectacles lenses--progressive lenses on middle and near distance. The main part of the paper is a comparison of functional differences among different types of progressive spectacles lenses. The paper also addresses correctness of choice of progressive lenses for different works and professions. Lastly, it elaborates on differences of centration of different types of progressive lenses and parameters for correct choice of glasses frame for progressive spectacles lenses. PMID:23837232

  16. [Intraocular Pressure Sensor Based on a Contact Lens].

    Science.gov (United States)

    Guo, Xuhong; Pet, Weihua; Yao, Zhaolin; Chen, Yuanfang; Hu, Xiaohui; Chen, Hongda; Zhu, Jingyuan; Wu, Huijuan

    2016-02-01

    Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition. PMID:27382734

  17. Effects of 2-alkynyladenosine derivatives on intraocular pressure in rabbits.

    Science.gov (United States)

    Konno, Takashi; Ohnuma, Shin-ya; Uemoto, Kazuhiro; Uchibori, Takehiro; Nagai, Akihiko; Kogi, Kentaro; Endo, Kazuki; Hosokawa, Tomokazu; Nakahata, Norimichi

    2004-02-23

    We evaluated the activities of 2-alkynyladenosine derivatives, relatively selective adenosine A2 receptor agonists, in the intraocular pressure regulation in rabbits. An adenosine A2 receptor agonist 2-[p-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine (CGS-21680) decreased intraocular pressure, while another A2 receptor agonist 2-(phenylamino)adenosine transiently increased it. The first group of 2-alkynyladenosine derivatives (1-hexyn-1-yl derivatives) caused a transient increase followed by decrease in intraocular pressure, while the second group (1-octyn-1-yl and 6-cyano-1-hexyn-1-yl derivatives) only decreased it. The second group is also effective in the ocular hypertensive models induced by water-loading and alpha-chymotrypsin. The outflow facility was increased by a 1-octyn-1-yl derivative. Both increase and decrease in intraocular pressure induced by 2-alkynyladenosine derivatives were inhibited by an adenosine A2 receptor antagonist 3,7-dimethyl-1-propargylxanthine, but not by an adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropyl xanthine. These findings suggest that 2-alkynyladenosine derivatives may affect intraocular pressure via adenosine A2 receptor, and 2-alkynyladenosine derivative-induced ocular hypotension is due to the increase of outflow facility.

  18. Effects of 2-alkynyladenosine derivatives on intraocular pressure in rabbits.

    Science.gov (United States)

    Konno, Takashi; Ohnuma, Shin-ya; Uemoto, Kazuhiro; Uchibori, Takehiro; Nagai, Akihiko; Kogi, Kentaro; Endo, Kazuki; Hosokawa, Tomokazu; Nakahata, Norimichi

    2004-02-23

    We evaluated the activities of 2-alkynyladenosine derivatives, relatively selective adenosine A2 receptor agonists, in the intraocular pressure regulation in rabbits. An adenosine A2 receptor agonist 2-[p-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine (CGS-21680) decreased intraocular pressure, while another A2 receptor agonist 2-(phenylamino)adenosine transiently increased it. The first group of 2-alkynyladenosine derivatives (1-hexyn-1-yl derivatives) caused a transient increase followed by decrease in intraocular pressure, while the second group (1-octyn-1-yl and 6-cyano-1-hexyn-1-yl derivatives) only decreased it. The second group is also effective in the ocular hypertensive models induced by water-loading and alpha-chymotrypsin. The outflow facility was increased by a 1-octyn-1-yl derivative. Both increase and decrease in intraocular pressure induced by 2-alkynyladenosine derivatives were inhibited by an adenosine A2 receptor antagonist 3,7-dimethyl-1-propargylxanthine, but not by an adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropyl xanthine. These findings suggest that 2-alkynyladenosine derivatives may affect intraocular pressure via adenosine A2 receptor, and 2-alkynyladenosine derivative-induced ocular hypotension is due to the increase of outflow facility. PMID:14985053

  19. [Intraocular Pressure Sensor Based on a Contact Lens].

    Science.gov (United States)

    Guo, Xuhong; Pet, Weihua; Yao, Zhaolin; Chen, Yuanfang; Hu, Xiaohui; Chen, Hongda; Zhu, Jingyuan; Wu, Huijuan

    2016-02-01

    Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition.

  20. Intercalation of acrylic acid and sodium acrylate into kaolinite and their in situ polymerization

    Science.gov (United States)

    Zhang, Bo; Li, Yanfeng; Pan, Xiaobing; Jia, Xin; Wang, Xiaolong

    2007-02-01

    Novel nano-composites of poly (acrylic acid)-kaolinite were prepared, and intercalation and in situ polymerization were used in this process. The nano-composites were obtained by in situ polymerization of acrylic acid (AA) and sodium acrylate (AANa) intercalated into organo-kaolinite, which was obtained by refining and chemically modifying with solution intercalation step in order to increase the basal plane distance of the original clay. The modification was completed by using dimethyl-sulfoxide (DMSO)/methanol and potassium acetate (KAc)/water systems step by step. The materials were characterized with the help of XRD, FT-IR and TEM; the results confirmed that poly(acrylic acid) (PAA) and poly(sodium acrylate) (PAANa) were intercalated into the interlamellar spaces of kaolinite, the resulting copolymer composites (CC0 : copolymer crude kaolinite composite, CC1 : copolymer DMSO kaolinite composite, CC2 : copolymer KAc kaolinite composite) of CC2 exhibited a lamellar nano-composite with a mixed nano-morphology, and partial exfoliation of the intercalating clay platelets should be the main morphology. Finally, the effect of neutralization degree on the intercalation behavior was also investigated.

  1. 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…

  2. Modern scleral lenses part I: clinical features.

    NARCIS (Netherlands)

    Visser, E.S.; Visser, R.; Lier, H.J.J. van; Otten, H.M.

    2007-01-01

    PURPOSE: To evaluate the indications for modern scleral lenses and their clinical performance in patients who were fitted with scleral lenses at the authors' practices. METHODS: In this cross-sectional survey, all the necessary data were obtained at the first follow-up visit during the 5-month study

  3. Acrylic Bone Cements Modified with Starch

    OpenAIRE

    Krilova, V; Vītiņš, V

    2010-01-01

    The successful result of restorative and replacement surgical operation depends significantly on properties of used bone cement. Acrylic bone cements are usually based on methylmethacrylate polymer, while monomer polymerization begins after mixing of components in mixing device and terminates in living tissue. Polymerization of methylmethacrylate is exothermic process, and temperature increase might cause tissue necrosis with concomitant implant aseptic loosening. Developed non-ionogenic and ...

  4. Gravitational Lensing: Strong, Weak and Micro

    CERN Document Server

    Schneider, Peter; Wambsganss, Joachim

    2006-01-01

    The theory, observations, and applications of gravitational lensing constitute one of the most rapidly growing branches of astrophysics. The gravitational deflection of light generated by mass concentrations along a light path produces magnification, multiplicity, and distortion of images and delays photon propagation from one line of sight relative to another. The huge amount of scientific work on gravitational lensing produced over the last decade has clearly revealed its already substantial and wide impact and its potential for future astrophysical applications. The up-to-date contributions in this book are based on the lecture notes of the 33rd Saas–Fee Advanced Course of the Swiss Society of Astronomy and Astrophysics, entitled Gravitational Lensing: Strong, Weak, and Micro. The book comprises four complementary parts, written by leading experts in the field, constituting a genuine textbook about gravitational lensing: • Peter Schneider – Part 1: Introduction to Gravitational Lensing and Cosmology ...

  5. New lensed quasars from the MUSCLES survey

    CERN Document Server

    Jackson, Neal; Ofek, Eran O; Shin, Min-Su

    2011-01-01

    Gravitational lens systems containing lensed quasars are important as cosmological probes, as diagnostics of structural properties of the lensing galaxies and as tools to study the quasars themselves. The largest lensed quasar sample is the SDSS Quasar Lens Search, drawn from the Sloan Digital Sky Survey (SDSS). We are attempting to extend this survey using observations of lens candidates selected from a combination of the quasar sample from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). This adds somewhat higher image quality together with a wider range of wavelength for the selection process. In previous pilot surveys we observed 5 objects, finding 2 lenses; here we present further observations of 20 objects in which we find 4 lenses, of which 2 are independently discovered in SQLS (in preparation). Following earlier work on the combination of these two surveys, we have refined our method and find that use of a colour-separation diagnostic, where we select for separations between components which...

  6. Gravitational Lensing of Cosmic Microwave Background Polarization

    CERN Document Server

    Ade, P A R; Anthony, A E; Arnold, K; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Jeune, M Le; Lee, A T; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Schanning, I; Schenck, D E; Sherwin, B; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

    2013-01-01

    Primary fluctuations in both temperature and polarization of the Cosmic Microwave Background (CMB) reflect the properties of the Universe from the Big Bang until the photons decoupled from matter 380,000 years later. These primary fluctuations are then lensed by large-scale structures (such as clusters of galaxies and filaments of dark matter), with the result that the distribution and properties of dark matter, including the masses of neutrinos, can be determined more accurately by extracting the lensing information than through studying the primary fluctuations alone. Polarization lensing can give cleaner, higher resolution results than temperature lensing. The correlation of lensed CMB polarization with large-scale structure, traced through the Cosmic Infrared Background, was recently detected; however, this correlation does not trace all structure and depends on the relationship between the infrared flux from the galaxies and the underlying mass distribution. Here we report the detection of gravitational ...

  7. Geometry of weak lensing of CMB polarization

    CERN Document Server

    Challinor, A D; Challinor, Anthony; Chon, Gayoung

    2002-01-01

    Hu has presented a harmonic-space method for calculating the effects of weak gravitational lensing on the cosmic microwave background (CMB) over the full sky. Computing the lensed power spectra to first order in the deflection power requires one to formulate the lensing displacement beyond the tangent-space approximation. We point out that for CMB polarization this displacement must undergo geometric corrections on the spherical sky to maintain statistical isotropy of the lensed fields. Although not discussed by Hu, these geometric effects are implicit in his analysis. However, there they are hidden by an overly-compact notation that is both unconventional and rather confusing. Here we aim to ameliorate this deficiency by providing a rigorous derivation of the lensed spherical power spectra.

  8. Image processing challenges in weak gravitational lensing

    CERN Document Server

    Amara, Adam

    2011-01-01

    The field of weak gravitational lensing, which measures the basic properties of the Universe by studying the way that light from distant galaxies is perturbed as it travels towards us, is a very active field in astronomy. This short article presents a broad overview of the field, including some of the important questions that cosmologists are trying to address, such as understanding the nature of dark energy and dark matter. To do this, there is an increasing feeling within the weak lensing community that other disciplines, such as computer science, machine learning, signal processing and image processing, have the expertise that would bring enormous advantage if channelled into lensing studies. To illustrate this point, the article below outlines some of the key steps in a weak lensing analysis chain. The challenges are distinct at each step, but each could benefit from ideas developed in the signal processing domain. This article also gives a brief overview of current and planned lensing experiments that wi...

  9. Cosmology with Strong Lensing Systems

    CERN Document Server

    Cao, Shuo; Gavazzi, Raphaël; Piórkowska, Aleksandra; Zhu, Zong-Hong

    2015-01-01

    In this paper, we assemble a catalog of 118 strong gravitational lensing systems from SLACS, BELLS, LSD and SL2S surveys and use them to constrain the cosmic equation of state. In particular we consider two cases of dark energy phenomenology: $XCDM$ model where dark energy is modeled by a fluid with constant $w$ equation of state parameter and in Chevalier - Polarski - Linder (CPL) parametrization where $w$ is allowed to evolve with redshift: $w(z) = w_0 + w_1 \\frac{z}{1+z}$. We assume spherically symmetric mass distribution in lensing galaxies, but relax the rigid assumption of SIS model in favor to more general power-law index $\\gamma$, also allowing it to evolve with redshifts $\\gamma(z)$. Our results for the $XCDM$ cosmology show the agreement with values (concerning both $w$ and $\\gamma$ parameters) obtained by other authors. We go further and constrain the CPL parameters jointly with $\\gamma(z)$. The resulting confidence regions for the parameters are much better than those obtained with a similar metho...

  10. New trends in intraocular lens imaging

    Science.gov (United States)

    Millán, María S.; Alba-Bueno, Francisco; Vega, Fidel

    2011-08-01

    As a result of modern technological advances, cataract surgery can be seen as not only a rehabilitative operation, but a customized procedure to compensate for important sources of image degradation in the visual system of a patient, such as defocus and some aberrations. With the development of new materials, instruments and surgical techniques in ophthalmology, great progress has been achieved in the imaging capability of a pseudophakic eye implanted with an intraocular lens (IOL). From the very beginning, optical design has played an essential role in this progress. New IOL designs need, on the one hand, theoretical eye models able to predict optical imaging performance and on the other hand, testing methods, verification through in vitro and in vivo measurements, and clinical validation. The implant of an IOL requires a precise biometry of the eye, a prior calculation from physiological data, and an accurate position inside the eye. Otherwise, the effects of IOL calculation errors or misplacements degrade the image very quickly. The incorporation of wavefront aberrometry into clinical ophthalmology practice has motivated new designs of IOLs to compensate for high order aberrations in some extent. Thus, for instance, IOLs with an aspheric design have the potential to improve optical performance and contrast sensitivity by reducing the positive spherical aberration of human cornea. Monofocal IOLs cause a complete loss of accommodation that requires further correction for either distance or near vision. Multifocal IOLs address this limitation using the principle of simultaneous vision. Some multifocal IOLs include a diffractive zone that covers the aperture in part or totally. Reduced image contrast and undesired visual phenomena, such as halos and glare, have been associated to the performance of multifocal IOLs. Based on a different principle, accommodating IOLs rely on the effort of the ciliary body to increase the effective power of the optical system of the

  11. Penetrating Scleral Injury with Intraocular Foreign Body. A Case Report

    Directory of Open Access Journals (Sweden)

    Anay Martínez Díaz

    2014-04-01

    Full Text Available Ocular trauma is a health problem in the world today and a common cause of visual impairment leading to severe sequelae and psychological disorders. The case of a 46-year-old male patient who attended the Ophthalmology emergency services of the Dr. Gustavo Aldereguía Lima University General Hospital of Cienfuegos, recounting that while hammering iron on iron he felt that something entered his right eye, is presented. He suffered from pain, tearing, red eye and blurred vision. A penetrating scleral injury with an intraocular foreign body was diagnosed. Its study was conducted through biomicroscopy, orbital x-ray and ocular ultrasound. Surgical treatment by extracapsular lens extraction with intraocular lens implantation was performed using Blumenthal technique and pars plana approach for removal of the intraocular foreign body.

  12. 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.

  13. Planck 2015 results. XV. Gravitational lensing

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; 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.; Zonca, A.

    2016-09-01

    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 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 40 ≤ L ≤ 400, and an associated likelihood for cosmological parameter constraints. We find good agreement between our measurement of the lensing potential power spectrum and that found in the ΛCDM model that best fits the Planck temperature and polarization power spectra. Using the lensing likelihood alone we obtain a percent-level measurement of the parameter combination σ8Ω0.25m = 0.591 ± 0.021. We combine our determination of the lensing potential with the E-mode polarization, also measured by Planck, to generate an estimate of the lensing B-mode. We show that this lensing B-mode estimate is correlated with the B-modes observed directly by Planck at the expected level and with a statistical significance of 10σ, confirming Planck's sensitivity to this known sky signal. We also correlate our lensing potential estimate with the large-scale temperature anisotropies, detecting a cross-correlation at the 3σ level, as expected because of dark energy in the concordance ΛCDM model.

  14. Performance comparison of acrylic and thiol-acrylic resins in two-photon polymerization.

    Science.gov (United States)

    Jiang, Lijia; Xiong, Wei; Zhou, Yushen; Liu, Ying; Huang, Xi; Li, Dawei; Baldacchini, Tommaso; Jiang, Lan; Lu, Yongfeng

    2016-06-13

    Microfabrication by two-photon polymerization is investigated using resins based on thiol-ene chemistry. In particular, resins containing different amounts of a tetrafunctional acrylic monomer and a tetrafunctional thiol molecule are used to create complex microstructures. We observe the enhancement of several characteristics of two-photon polymerization when using thiol-acrylic resins. Specifically, microfabrication is carried out using higher writing velocities and it produces stronger polymeric microstructures. Furthermore, the amount of shrinkage typically observed in the production of three-dimensional microstructures is reduced also. By means of microspectrometry, we confirm that the thiol-acrylate mixture in TPP resins promote monomer conversion inducing a higher degree of cross-linked network formation. PMID:27410383

  15. Palladium (II) catalyized polymerization of norbornene and acrylates

    Science.gov (United States)

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2000-08-29

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: [(L)Pd(R)(X)].sub.2, where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  16. Palladium (Ii) Catalyzed Polymerization Of Norbornene And Acrylates

    Science.gov (United States)

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2001-10-09

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  17. Pulse radiolysis of aqueous solutions of ethyl acrylate and hydroxy ethyl acrylate

    Science.gov (United States)

    Safrany, A.; Biro, A.; Wojnarovits, L.

    1993-10-01

    Ethyl- and hydroxy ethyl acrylate show high reactivities with hydrated electron and hydroxyl radical intermediates of water radiolysis. The electron adduct reversibly protonate with pK values of 5.7 and 7.3. The adducts may take part in irreversible protonation at the β carbon atom forming α-carboxyl alkyl radicals. Same type of radical forms in reaction of acrylates with OH: at low concentration the adduct mainly disappear in self termination reactions. Above 5 mmol dm -1 the signals showed the startup of oligomerization.

  18. Polyvinylidene Flouride Polymer Applied in an Intraocular Pressure Sensor

    Science.gov (United States)

    González Morán, Carlos Omar; González Ballesteros, Rubén; Rodríguez Guzmán, Maria Dolores Alicia; Suaste Gómez, Ernesto

    2005-06-01

    An indentation intraocular pressure sensor (IIOPS) was designed and manufactured. It is based on piezoelectric polyvinylidene fluoride (PVDF) films. This sensor will help in the detection and diagnosis of intraocular pressure (IOP) in eye diseases like glaucoma. The pressure in the normal aqueous and vitreous phases is, on average, 15.5 mmHg and up of 21 mmHg when glaucoma exists. The proposed IIOPS offers a measurement range from 10-29 mmHg with a resolution of 1 mmHg and an accuracy of ± 0.025.

  19. Palm oil based polyols for acrylated polyurethane production

    International Nuclear Information System (INIS)

    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)

  20. Severe Onychodystrophy due to Allergic Contact Dermatitis from Acrylic Nails.

    Science.gov (United States)

    Mattos Simoes Mendonca, Marcela; LaSenna, Charlotte; Tosti, Antonella

    2015-09-01

    Acrylic nails, including sculptured nails and the new ultraviolet-curable gel polish lacquers, have been associated with allergic contact dermatitis (ACD). We report 2 cases of ACD to acrylic nails with severe onychodystrophy and psoriasiform changes including onycholysis and subungual hyperkeratosis. In both cases, the patients did not realize the association between the use of acrylate-based manicures and nail changes. One patient had been previously misdiagnosed and treated unsuccessfully for nail psoriasis. The informed clinician should elicit a history of acrylic manicure in patients with these nail changes, especially in cases of suspected nail psoriasis refractory to treatment. Patch testing is a useful tool in confirming diagnosis. PMID:27170940

  1. 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.

  2. Plasmonic Luneburg and Eaton Lenses

    CERN Document Server

    Zentgraf, Thomas; Mikkelsen, Maiken H; Valentine, Jason; Zhang, Xiang; 10.1038/NNANO.2010.282

    2011-01-01

    Plasmonics is an interdisciplinary field focusing on the unique properties of both localized and propagating surface plasmon polaritons (SPPs) - quasiparticles in which photons are coupled to the quasi-free electrons of metals. In particular, it allows for confining light in dimensions smaller than the wavelength of photons in free space, and makes it possible to match the different length scales associated with photonics and electronics in a single nanoscale device. Broad applications of plasmonics have been realized including biological sensing, sub-diffraction-limit imaging, focusing and lithography, and nano optical circuitry. Plasmonics-based optical elements such as waveguides, lenses, beam splitters and reflectors have been implemented by structuring metal surfaces or placing dielectric structures on metals, aiming to manipulate the two-dimensional surface plasmon waves. However, the abrupt discontinuities in the material properties or geometries of these elements lead to increased scattering of SPPs, ...

  3. Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens

    Directory of Open Access Journals (Sweden)

    Chang DH

    2016-08-01

    Full Text Available Daniel H Chang Empire Eye and Laser Center, Bakersfield, CA, USA Purpose: The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses. Methods: In this retrospective–prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50–81 years who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00 were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft, intermediate (70–80 cm, and near (35–40 cm under photopic (85 cd/m2 and mesopic (3 cd/m2 lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. Results: At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night. Conclusion: Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction. Keywords: Tecnis multifocal one-piece IOL, photopic visual acuity, mesopic visual acuity, intermediate visual

  4. Wettability and silicone hydrogel lenses: a review.

    Science.gov (United States)

    Keir, Nancy; Jones, Lyndon

    2013-01-01

    One of the major breakthroughs in the development of silicone hydrogel contact lenses has related to the ability of manufacturers to overcome the surface hydrophobicity that occurred with silicone elastomer lenses. However, the wettability of silicone hydrogel lenses continues to be of interest as a potential link between in vivo lens performance and contact lens-related comfort. This article will review some of the knowledge we have gained in the area of contact lens wettability over the past decade and will discuss some of the challenges related to its measurement. PMID:23274760

  5. Edge shape and comfort of rigid lenses.

    Science.gov (United States)

    La Hood, D

    1988-08-01

    One of the main factors determining the comfort of a rigid contact lens is the shape of the edge. The comfort of four different contact lens edge shapes was assessed with four unadapted subjects in a randomized masked trial. Lenses with well rounded anterior edge profiles were found to be significantly more comfortable than lenses with square anterior edges. There was no significant difference in subjective comfort between a rounded and square posterior edge profile. The results suggest that the interaction of the edge with the eyelid is more important in determining comfort than edge effects on the cornea, when lenses are fitted according to a corneal alignment philosophy. PMID:3177585

  6. 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

  7. Tevatron Electron Lenses: Design and Operation

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; /Fermilab; Bishofberger, Kip; /Los Alamos; Kamerdzhiev, Vsevolod; /Fermilab; Kozub, Sergei; /Serpukhov, IHEP; Kufer, Matthew; Kuznetsov, Gennady; Martinez, Alexander; Olson, Marvin; Pfeffer, Howard; Saewert, Greg; Scarpine, Vic; /Fermilab /SLAC /Fermilab /Serpukhov, IHEP /Novosibirsk, IYF /Serpukhov, IHEP /Fermilab

    2008-08-01

    The beam-beam effects have been the dominating sources of beam loss and lifetime limitations in the Tevatron proton-antiproton collider [1]. Electron lenses were originally proposed for compensation of electromagnetic long-range and head-on beam-beam interactions of proton and antiproton beams [2]. Results of successful employment of two electron lenses built and installed in the Tevatron are reported in [3,4,5]. In this paper we present design features of the Tevatron electron lenses (TELs), discuss the generation of electron beams, describe different modes of operation and outline the technical parameters of various subsystems.

  8. Nanofocusing refractive X-ray lenses

    International Nuclear Information System (INIS)

    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

  9. Twin axial vortices generated by Fibonacci lenses.

    Science.gov (United States)

    Calatayud, Arnau; Ferrando, Vicente; Remón, Laura; Furlan, Walter D; Monsoriu, Juan A

    2013-04-22

    Optical vortex beams, generated by Diffractive Optical Elements (DOEs), are capable of creating optical traps and other multi-functional micromanipulators for very specific tasks in the microscopic scale. Using the Fibonacci sequence, we have discovered a new family of DOEs that inherently behave as bifocal vortex lenses, and where the ratio of the two focal distances approaches the golden mean. The disctintive optical properties of these Fibonacci vortex lenses are experimentally demonstrated. We believe that the versatility and potential scalability of these lenses may allow for new applications in micro and nanophotonics. PMID:23609732

  10. Effect of chymase on intraocular pressure in rabbits.

    Science.gov (United States)

    Konno, Takashi; Maruichi, Midori; Takai, Shinji; Oku, Hidehiro; Sugiyama, Tetsuya; Uchibori, Takehiro; Nagai, Akihiko; Kogi, Kentaro; Ikeda, Tsunehiko; Miyazaki, Mizuo

    2005-11-01

    Chymase is a chymotrypsin-like serine protease that is stored exclusively in the secretory granules of mast cells and converts big endothelins to endothelin-1 (1-31). The aim of this study was to evaluate the effect of chymase on intraocular pressure in rabbits. Chymase injection (3 and 10 mU) resulted in a trend toward increased intraocular pressure and a significant increase in intraocular pressure at a dose of 10 mU compared with the control. A specific chymase inhibitor, Suc-Val-Pro-Phe(P)(OPh)(2), attenuated the ocular hypertension induced by chymase. Endothelin-1 (1-31) also caused ocular hypertension, which was inhibited by a selective endothelin ET(A) receptor antagonist, cyclo(D-Asp-Pro-D-Val-Leu-D-Trp) (BQ-123). Moreover, chymase-induced ocular hypertension was inhibited by BQ-123. These results suggest that chymase influences the regulation of intraocular pressure, and it is likely that the formation of endothelin-1 (1-31) and subsequent activation of endothelin ET(A) receptors are involved in the development of ocular hypertension induced by chymase.

  11. Intraocular inflammation following endotamponade with high-density silicone oil.

    NARCIS (Netherlands)

    Theelen, T.; Tilanus, M.A.D.; Klevering, B.J.

    2004-01-01

    BACKGROUND: The use of a mixture of silicone oil and partially fluorinated alkanes (high-density silicone oil) has recently been suggested as intraocular tamponade in complicated retinal detachment of the inferior quadrants. We describe a series of patients who developed a clinical picture resemblin

  12. Hematoporphyrin derivative photoradiation therapy for the treatment of intraocular tumors

    International Nuclear Information System (INIS)

    Hematoporphyrin derivative (HpD) photoradiation therapy (PRT) is currently being examined for the treatment of intraocular tumors (retinoblastoma and uveal melanoma). HpD is preferentially retained in malignant tissue and tumorcidal action can be induced when HpD is activated with visible red light. Preclinical studies have been conducted using pigmented rabbits having transplanted intraocular tumors. A dye laser system has been used to generate red light (630 nm) for localized irradiation of ocular tissue following I.V. administration of HpD. The authors have previously reported that acute toxicity to normal retina (in the form of retinal necrosis) can be induced by HpD PRT, and that this damage can be limited to the treatment field. The results of current preclinical studies related to long term ocular toxicity, HpD distribution in ocular tissue and intraocular tumor tissue response following HpD PRT are presented. In addition, initial clinical results of intraocular HpD PRT are described

  13. Combined aniridic intraocular lens implantation and vitreoretinal surgery

    Science.gov (United States)

    Mehta, Hijab; Jayadev, Chaitra; Natarajan, S

    2007-01-01

    A 45-year-old man presented with post-traumatic aniridia. We describe the combined surgery done to treat both aniridia and epiretinal membrane simultaneously. A combined aniridia intraocular lens and vitreoretinal surgery was done. The case report highlights the advantage of combined surgery in terms of cost factor and surgical time. PMID:17699956

  14. Combined aniridic intraocular lens implantation and vitreoretinal surgery

    OpenAIRE

    Mehta Hitendra; Mehta Hijab; Jayadev Chaitra; Natarajan S

    2007-01-01

    A 45-year-old man presented with post-traumatic aniridia. We describe the combined surgery done to treat both aniridia and epiretinal membrane simultaneously. A combined aniridia intraocular lens and vitreoretinal surgery was done. The case report highlights the advantage of combined surgery in terms of cost factor and surgical time.

  15. Development of a ciliary muscle-driven accommodating intraocular lens

    NARCIS (Netherlands)

    Hermans, Erik A.; Terwee, Thom T.; Koopmans, Steven A.; Dubbelman, Michiel; van der Heijde, Rob G. L.; Heethaar, Rob M.

    2008-01-01

    PURPOSE: To develop a ciliary muscle-driven accommodating intraocular lens (IOL) that has a large and predictable range of variable power as a step toward spectacle independence. SETTING: Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands. METHODS:

  16. Effect of chymase on intraocular pressure in rabbits.

    Science.gov (United States)

    Konno, Takashi; Maruichi, Midori; Takai, Shinji; Oku, Hidehiro; Sugiyama, Tetsuya; Uchibori, Takehiro; Nagai, Akihiko; Kogi, Kentaro; Ikeda, Tsunehiko; Miyazaki, Mizuo

    2005-11-01

    Chymase is a chymotrypsin-like serine protease that is stored exclusively in the secretory granules of mast cells and converts big endothelins to endothelin-1 (1-31). The aim of this study was to evaluate the effect of chymase on intraocular pressure in rabbits. Chymase injection (3 and 10 mU) resulted in a trend toward increased intraocular pressure and a significant increase in intraocular pressure at a dose of 10 mU compared with the control. A specific chymase inhibitor, Suc-Val-Pro-Phe(P)(OPh)(2), attenuated the ocular hypertension induced by chymase. Endothelin-1 (1-31) also caused ocular hypertension, which was inhibited by a selective endothelin ET(A) receptor antagonist, cyclo(D-Asp-Pro-D-Val-Leu-D-Trp) (BQ-123). Moreover, chymase-induced ocular hypertension was inhibited by BQ-123. These results suggest that chymase influences the regulation of intraocular pressure, and it is likely that the formation of endothelin-1 (1-31) and subsequent activation of endothelin ET(A) receptors are involved in the development of ocular hypertension induced by chymase. PMID:16253233

  17. Impact factors on intraocular pressure measurements in healthy subjects.

    NARCIS (Netherlands)

    Theelen, T.; Meulendijks, C.F.M.; Geurts, D.; Leeuwen, A.M. van; Voet, N.B.; Deutman, A.F.

    2004-01-01

    AIM: To evaluate whether intraocular pressure (IOP) calculation by applanation tonometry is determined more essentially by the subject's neck position or by neck constriction. METHODS: 23 right eyes of 23 healthy subjects (12 male, 11 female) were included. IOP was measured by applanation tonometry

  18. Combined aniridic intraocular lens implantation and vitreoretinal surgery

    Directory of Open Access Journals (Sweden)

    Mehta Hitendra

    2007-01-01

    Full Text Available A 45-year-old man presented with post-traumatic aniridia. We describe the combined surgery done to treat both aniridia and epiretinal membrane simultaneously. A combined aniridia intraocular lens and vitreoretinal surgery was done. The case report highlights the advantage of combined surgery in terms of cost factor and surgical time.

  19. Liquid-crystal intraocular adaptive lens with wireless control

    NARCIS (Netherlands)

    Simonov, A.N.; Vdovine, G.V.; Loktev, M.

    2007-01-01

    We present a prototype of an adaptive intraocular lens based on a modal liquid-crystal spatial phase modulator with wireless control. The modal corrector consists of a nematic liquid-crystal layer sandwiched between two glass substrates with transparent low- and high-ohmic electrodes, respectively.

  20. Long-term visual outcomes after Crystalens® HD intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Karavitaki AE

    2014-05-01

    Full Text Available Alexandra E Karavitaki, Ioannis G Pallikaris, Sophia I Panagopoulou, George A Kounis, George Kontadakis, George D KymionisInstitute of Vision and Optics, University of Crete, Crete, GreecePurpose: Our purpose was to evaluate the long-term visual outcomes after bilateral implantation of Crystalens® HD (Bausch and Lomb, Inc. accommodative intraocular lenses.Methods: In this study, 25 patients (50 eyes who underwent cataract surgery and bilateral Crystalens HD accommodative intraocular lens implantation were included. The Crystalens HD lens was implanted in the bag in both eyes, without any intra- or postoperative complications. The visual parameters measured before and after surgery were: uncorrected distance visual acuity, corrected distance visual acuity (CDVA (using the Early Diabetic Retinopathy Study [EDTRS] logMAR charts, uncorrected intermediate visual acuity, and uncorrected near visual acuity using a Birkhäuser reading chart, at a distance of 66 cm and 33 cm for intermediate and near vision, respectively, directly illuminated by a lamp of 60 watts. After surgery, the patients were evaluated at 1, 3, 6, 12, 24, and 36 months.Results: The mean age was 68.70±7.1 (range: 54 to 83 years. The mean follow-up was 42.72±0.49 (range: 42.33 to 43.27 months. The uncorrected distance visual acuity improved from 0.56±0.41 (range: 0 to 2 preoperatively to 0.19±0.13 (range: 0 to 0.38 (logMAR scale at the last follow-up visit, and the CDVA improved from 0.17±0.18 (range: 0 to 0.7 preoperatively to 0.05±0.05 (range: −0.02 to 0.22 at the last follow-up visit. No eyes lost lines of CDVA during the follow-up period, while 54% of patients gained one or more lines of CDVA. The uncorrected intermediate and near visual acuity was J2 or better in 71% and 69% of our patients, respectively.Conclusion: Crystalens HD implantation seems to provide an improvement in visual acuity for far, intermediate, and near distances.Keywords: presbyopia, accommodation

  1. Comparative study of two silicone hydrogel contact lenses used as bandage contact lenses after photorefractive keratectomy

    OpenAIRE

    Hasan Razmjoo; Elham Abdi; Sayna Atashkadi; Akhlaghi M Reza; Peyman A Reza; Mojtaba Akbari

    2012-01-01

    Background: Silicon hydrogel bandage contact lenses are used to enhance epithelial healing, control surface-generated pain, and prevent epithelial erosions after refractive surgery. Considering the importance of faster reepithelialization in preventing complications of photorefractive keratectomy (PRK) and the fact that the features and specifications of these commercially-available lenses are different and their performance as a postoperative bandage lenses would be different also, the aim o...

  2. Comparison of Spectacle Classical Progressive and Office Progressive Lenses

    OpenAIRE

    Kozlík, Marek; Nováková Knollová, Libuše

    2013-01-01

    This paper elaborates on analysis of progressive spectacle lenses, to correct presbyopia, which are nowadays offered at the market. The paper describes different types of progressive lenses, their parameters, length and width of their progressive segments. It also describes degressive spectacles lenses – progressive lenses on middle and near distance. The main part of the paper is a comparison of functional differences among different types of progressive spectacles lenses. The paper also add...

  3. Safety and efficacy of phacoemulsification and intraocular lens implantation through a small pupil using minimal iris manipulation

    Science.gov (United States)

    Papaconstantinou, Dimitris; Kalantzis, George; Brouzas, Dimitris; Kontaxakis, Anastasios; Koutsandrea, Chryssanthi; Diagourtas, Andreas; Georgalas, Ilias

    2016-01-01

    Purpose The aim of this study was to compare the results of phacoemulsification through a small pupil using minimal iris manipulation versus phacoemulsification through a well-dilated pupil. Methods This prospective randomized control (comparative) study comprised 78 patients (group I) with a maximally dilated pupil size of ≤4.00 mm and 45 patients (group II) with dilated pupil size of ≥7.00 mm. In group I patients, only viscodilation and minimal push-and-pull iris stretching with two collar-button iris-retractor hooks were utilized without iris manipulation. Phacoemulsification was performed by two senior surgeons and the technique used consisted of either stop and chop or quick chop, infusion/aspiration of lens cortex, capsular bag refill with ocular viscoelastic devices, and implantation of an acrylic foldable intraocular lens. Patients were examined on the first day and 1 month postoperatively. Results Forty-six eyes of group I patients had pseudoexfoliation syndrome, eleven eyes had previous glaucoma surgery, 14 eyes had angle-closure or open-angle glaucoma, and seven eyes had posterior synechiae with iritis. In group I patients, the mean pupil size measured under an operating microscope was 3.2 mm preoperatively, 4.3 mm after viscoelastic and mechanical pupil dilation, and 4.1 mm at the end of a surgical procedure. Rupture of the zonular fibers occurred in six patients of group I and the intraocular lens was implanted in the sulcus. Small iris-sphincter rupture and small hemorrhages occurred in four eyes during pupillary manipulation, but they were not evident at the end of the surgery. In group II patients, no intraoperative complications occurred. Signs of significant corneal edema and iritis were observed more frequently in group I eyes (26 eyes and 20 eyes, respectively) on the first postoperative day in comparison with group II eyes (ten eyes and six eyes, respectively). Intraocular pressure was <20 mmHg in all eyes of both groups. One month

  4. Safety and efficacy of phacoemulsification and intraocular lens implantation through a small pupil using minimal iris manipulation

    Directory of Open Access Journals (Sweden)

    Papaconstantinou D

    2016-05-01

    Full Text Available Dimitris Papaconstantinou, George Kalantzis, Dimitris Brouzas, Anastasios Kontaxakis, Chryssanthi Koutsandrea, Andreas Diagourtas, Ilias Georgalas Department of Ophthalmology, National and Kapodistrian University of Athens, Athens, Greece Purpose: The aim of this study was to compare the results of phacoemulsification through a small pupil using minimal iris manipulation versus phacoemulsification through a well-dilated pupil.Methods: This prospective randomized control (comparative study comprised 78 patients (group I with a maximally dilated pupil size of ≤4.00 mm and 45 patients (group II with dilated pupil size of ≥7.00 mm. In group I patients, only viscodilation and minimal push-and-pull iris stretching with two collar-button iris-retractor hooks were utilized without iris manipulation. Phacoemulsification was performed by two senior surgeons and the technique used consisted of either stop and chop or quick chop, infusion/aspiration of lens cortex, capsular bag refill with ocular viscoelastic devices, and implantation of an acrylic foldable intraocular lens. Patients were examined on the first day and 1 month postoperatively.Results: Forty-six eyes of group I patients had pseudoexfoliation syndrome, eleven eyes had previous glaucoma surgery, 14 eyes had angle-closure or open-angle glaucoma, and seven eyes had posterior synechiae with iritis. In group I patients, the mean pupil size measured under an operating microscope was 3.2 mm preoperatively, 4.3 mm after viscoelastic and mechanical pupil dilation, and 4.1 mm at the end of a surgical procedure. Rupture of the zonular fibers occurred in six patients of group I and the intraocular lens was implanted in the sulcus. Small iris-sphincter rupture and small hemorrhages occurred in four eyes during pupillary manipulation, but they were not evident at the end of the surgery. In group II patients, no intraoperative complications occurred. Signs of significant corneal edema and iritis

  5. Comparison of classical dermatoscopy and acrylic globe magnifier dermatoscopy

    DEFF Research Database (Denmark)

    Lorentzen, Henrik F; Eefsen, Rikke Løvendahl; Weismann, Kaare

    2008-01-01

    to histopathology diagnoses, assessed dermatoscopic and acrylic globe magnifier photo-slides according to the dermoscopic risk stratification. The observed agreement over all categories between acrylic globe magnifier dermatoscopy and classical dermatoscopy was 94% and Cohen's kappa coefficient was 90% (95...

  6. 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...

  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. Intrinsic Galaxy Alignments and Weak Gravitational Lensing

    CERN Document Server

    Heavens, A F

    2001-01-01

    Gravitational lensing causes background galaxy images to become aligned, and the statistical characteristics of the image alignments can then be used to constrain the power spectrum of mass fluctuations. Analyses of gravitational lensing assume that intrinsic galaxy alignments are negligible, but if this assumption does not hold, then the interpretation of image alignments will be in error. As gravitational lensing experiments become more ambitious and seek very low-level alignments arising from lensing by large-scale structure, it becomes more important to estimate the level of intrinsic alignment in the galaxy population. In this article, I review the cluster of independent theoretical studies of this issue, as well as the current observational status. Theoretically, the calculation of intrinsic alignments is by no means straightforward, but some consensus has emerged from the existing works, despite each making very different assumptions. This consensus is that a) intrinsic alignments are a small but non-n...

  9. Cosmological applications of strong gravitational lensing

    DEFF Research Database (Denmark)

    Paraficz, Danuta

    value of the energy density of the two above components, together with measuring the Hubble constant that determines the age of the Universe, is a major goal of modern astrophysics. An interesting method for estimating these parameters is strong gravitational lensing of quasars (QSOs). As shown....... The first Chapter presents a historical background of gravitational lensing. It explains the process involved in creating the theory of gravitational lenses. It shows how Newton and then Einstein developed the concept and how Refsdal and others made it a cosmological tool. We present in more detail how...... gravitational lensing influenced the history of physics by being the first proof of Einstein's theory of gravity. The Chapter ends by discussing the first observational discovery of a strong gravitational lens....

  10. The Bianchi identity and weak gravitational lensing

    Energy Technology Data Exchange (ETDEWEB)

    Kling, Thomas P; Keith, Brian [Department of Physics, Bridgewater State College, Bridgewater, MA 02325 (United States)

    2005-07-21

    We consider the Bianchi identity as a field equation for the distortion of the shapes of images produced by weak gravitational lensing. Using the spin coefficient formalism of Newman and Penrose (1962 J. Math. Phys. 3 566-78), we show that certain complex components of the Weyl and Ricci curvature tensors are directly related to fundamental observables in weak gravitational lensing. In the case of weak gravitational fields, we then show that the Bianchi identity provides a field equation for the Ricci tensor assuming a known Weyl tensor. From the Bianchi identity, we derive the integral equation for weak lensing presented by Miralda-Escude (1996 IAU Symp. vol 173 p 131), thus making the Bianchi identity a first principles equation of weak gravitational lensing. This equation is integrated in the important case of an axially symmetric lens and explicitly demonstrated in the case of a point lens and a singular isothermal sphere (SIS) model.

  11. Doubling Strong Lensing as a Cosmological Probe

    CERN Document Server

    Linder, Eric V

    2016-01-01

    Strong gravitational lensing provides a geometric probe of cosmology in a unique manner through distance ratios involving the source and lens. This is well known for the time delay distance derived from measured delays between lightcurves of the images of variable sources such as quasars. Recently, double source plane lens systems involving two constant sources lensed by the same foreground lens have been proposed as another probe, involving a different ratio of distances measured from the image positions and fairly insensitive to the lens modeling. Here we demonstrate that these two different sets of strong lensing distance ratios have strong complementarity in cosmological leverage. Unlike other probes, the double source distance ratio is actually more sensitive to the dark energy equation of state parameters $w_0$ and $w_a$ than to the matter density $\\Omega_m$, for low redshift lenses. Adding double source distance ratio measurements can improve the dark energy figure of merit by 40% for a sample of fewer...

  12. Comparison of a new-generation sectorial addition multifocal intraocular lens and a diffractive apodized multifocal intraocular lens.

    NARCIS (Netherlands)

    Linden, J.W.M. van der; Velthoven, M. van; Meulen, I. van der; Nieuwendaal, C.; Mourits, M.; Lapid-Gortzak, R.

    2012-01-01

    PURPOSE: To compare visual, refractive, and satisfactory outcomes between a new-generation sectorial addition multifocal intraocular lens (IOL) (Lentis Mplus LS-312; study group) and a diffractive apodized multifocal IOL (Restor SN6AD1; control group). SETTING: Private practice, Driebergen, and Depa

  13. The Origin of Weak Lensing Convergence Peaks

    OpenAIRE

    Liu, Jia; Haiman, Zoltan

    2016-01-01

    Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on $\\Omega_m$ and $\\sigma_8$ are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational da...

  14. Coatings and Tints of Spectacle Lenses

    OpenAIRE

    H. Zeki Büyükyıldız

    2012-01-01

    Spectacle lenses are made of mineral or organic (plastic) materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1) Anti-reflection coatings, 2) Hard coatings, 3) Clean coat, 4) Mirror coatings, 5) Color tint coating (one of coloring processes), 6) Photochromic coating (one of photochromic processes), and 7) Anti-fog...

  15. Chromagen lenses and abnormal colour perception

    OpenAIRE

    O. Matthew Oriowo; Abdullah Z. Alotaibi

    2011-01-01

    Background: The Chromagen lens system comprises of tinted spectacle or contact lenses, each with a specific colour wavelength filter which controls the spectra of the light entering the eye. This study investigated whether spectacle-mounted Chromagen lenses would enhance colour perception in individuals with abnormal colour vision.Methods: The Ishihara colour test was used to test for colour vision deficiency (CVD) and also to evaluate the effect of the Chromagen spectacle lens on colour perc...

  16. Occupational fingertip eczema from acrylates in a manicurist

    Directory of Open Access Journals (Sweden)

    Denitza Zheleva

    2015-04-01

    Full Text Available Occupational hand eczema due to acrylates present in the workplace is a disease frequently reported among dentists, printers, and fiberglass workers. Acrylate monomers are used in the production of a great variety of polymers, including nail cosmetics. Our case report demonstrates a rare clinical presentations of allergic contact dermatitis from acrylic nails. Our patient was working as a manicurist and the diagnostic analyses revealed sensitation to some of the (meth acrylate compounds of her new nail cosmetics. Sculptured artificial acrylic and UV-hardened nails s are widely used in developed countries and they are gaining more and more popularity. We expect an increase in the number of cases of contact allergic dermatitis among manicurists and customers.

  17. Cosmological test using strong gravitational lensing systems

    CERN Document Server

    Yuan, C C

    2015-01-01

    As one of the probes of universe, strong gravitational lensing systems allow us to compare different cosmological models and constrain vital cosmological parameters. This purpose can be reached from the dynamic and geometry properties of strong gravitational lensing systems, for instance, time-delay $\\Delta\\tau$ of images, the velocity dispersion $\\sigma$ of the lensing galaxies and the combination of these two effects, $\\Delta\\tau/\\sigma^2$. In this paper, in order to carry out one-on-one comparisons between $\\Lambda$CDM universe and $R_h=ct$ universe, we use a sample containing 36 strong lensing systems with the measurement of velocity dispersion from the SLACS and LSD survey. Concerning the time-delay effect, 12 two-image lensing systems with $\\Delta\\tau$ are also used. In addition, Monte Carlo (MC) simulations are used to compare the efficiency of the three methods as mentioned above. From simulations, we estimate the number of lenses required to rule out one model at the $99.7\\%$ confidence level. Compar...

  18. Statistical challenges in weak lensing cosmology

    CERN Document Server

    Takada, Masahiro

    2014-01-01

    Cosmological weak lensing is the powerful probe of cosmology. Here we address one of the most fundamental, statistical questions inherent in weak lensing cosmology: whether or not we can recover the initial Gaussian information content of large-scale structure by combining the weak lensing observables, here focused on the weak lensing power spectrum and bispectrum. To address this question we fully take into account correlations between the power spectra of different multipoles and the bispectra of different triangle configurations, measured from a finite area survey. In particular we show that super-survey modes whose length scale is larger than or comparable with the survey size cause significant sample variance in the weak lensing correlations via the mode-coupling with sub-survey modes due to nonlinear gravitational clustering -- the so-called super-sample variance. In this paper we discuss the origin of the super-sample variance and then study the information content inherent in the weak lensing correlat...

  19. Ophthalmic glucose monitoring using disposable contact lenses.

    Science.gov (United States)

    Geddes, Chris

    2004-01-01

    We have developed a range of disposable and colorless tear glucose sensing contact lenses, using off-the-shelf lenses embedded with new water soluble, highly fluorescent and glucose sensitive boronic acid containing fluorophores. The new lenses are readily able to track tear glucose levels and therefore blood glucose levels, which are ideally suited for potential use by diabetics. The fluorescence responses from the lenses can be monitored using simple excitation and emission detection devices. The novelty of our approach is two fold. Firstly, the notion of sensing extremely low glucose concentrations in tears, which track blood levels, by our contact lens approach, and secondly, the unique compatibility of our new glucose signaling probes with the internal mildly acidic contact lens environment. The new lenses are therefore ideal for the noninvasive and continuous monitoring of tear glucose, with a 15 minute response time, and a measured shelf life in excess of 3 months. In this invited article, we show that fluorescence based signaling using plastic disposable lenses, which have already been industrially optimized with regard to vision correction and oxygen / analyte permeability etc, may a notable alternative to invasive and random finger pricking, the most widely used glucose monitoring technology by diabetics. PMID:17271473

  20. 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.

  1. Polymethyl methacrylate intraocular lens opacification 20 years after cataract surgery: A case report in a tertiary eye hospital in Saudi Arabia.

    Science.gov (United States)

    Al-Otaibi, Abdullah G; Al-Qahtani, Elham S

    2012-01-01

    Snowflake degeneration is a slow progressive opacification of polymethyl methacrylate (PMMA) intraocular lenses (IOLs). This late postoperative complication can occur a decade or later after implantation. The deposits are composed of IOL materials that tend to aggregate centrally. There is a relative paucity of the literature on snowflake degeneration of IOLs. Symptoms can range from mild visual disturbance to significant loss of visual acuity. In cases of opacification after IOL implantation, the different diagnosis should include snowflake degeneration to prevent surgical intervention such as lens exchange or explantation unless clinically warranted. We report a case of late optical opacification of a PMMA IOL, the clinical diagnosis and treatment that increased best corrected vision. PMID:23960977

  2. Degeneracy between Lensing and Occultation in the Analysis of Self-lensing Phenomena

    CERN Document Server

    Han, Cheongho

    2016-01-01

    More than 40 years after the first discussion, it was recently reported the detection of a self-lensing phenomenon within a binary system where the brightness of a background star is magnified by its foreground companion. It is expected that the number of self-lensing binary detections will be increased in a wealth of data from current and future survey experiments. In this paper, we introduce a degeneracy in the interpretation of self-lensing light curves. The degeneracy is intrinsic to self-lensing binaries for which both magnification by lensing and de-magnification by occultation occur simultaneously and is caused by the difficulty in separating the contribution of the lensing-induced magnification from the observed light curve. We demonstrate the severity of the degeneracy by presenting example self-lensing light curves suffering from the degeneracy. We also present the relation between the lensing parameters of the degenerate solutions. The degeneracy would pose as an important obstacle in accurately de...

  3. Quantitative Measurements of the Decentration Distance of Four Kinds of Intraocular Lens

    Institute of Scientific and Technical Information of China (English)

    Bo Feng; Zhende Lin; Jianjing Li; Yonghua Li

    2004-01-01

    Purpose:To investigate a quantitative method to measure decentration distance(DD) and analyze the DD of four kinds of intraocular lenses (IOLs).Methods :The pseudophakic eye photos were taken under the slit lamp after the IOLs were implanted a year or longer. Then the images were inputted into a computer and the Photoshop software was applied to analyze the DD. Four kinds of IOLs were analyzed,including AcrySof MA60BM (11 eyes), Allergan SA40N (11 eyes), AcrySof SA60AT/SA30AL (5 eyes), Corneal Quattro (4 eyes).Results:The mean value of DD was (0.264 3±0.157 4)mm in the AcrySof MA60BM group,(0.353 6±0.171 9)mm in the Array SA40N group,(0.309 9±0.152 9)mm in the SA60AT/SA30AL group, and (0.326 1±0.187 7)mm in the Quattro group, The difference of the DD values among these 4 kinds of IOLs had no statistic significance (F=0.506,P=0.681) and the values were not equal to zero (t=10.508, P < 0.001). Conclusion:The Photoshop method is a simple and efficient way for DD analysis. The modern foldable posterior-chamber-IOLs have good centration performances when implanted into the capsular bags. Eye Science 2004;20:48-51.

  4. Outcomes of excimer laser enhancements in pseudophakic patients with multifocal intraocular lens

    Science.gov (United States)

    Schallhorn, Steven C; Venter, Jan A; Teenan, David; Schallhorn, Julie M; Hettinger, Keith A; Hannan, Stephen J; Pelouskova, Martina

    2016-01-01

    Purpose The aim of this study was to assess visual and refractive outcomes of laser vision correction (LVC) to correct residual refraction after multifocal intraocular lens (IOL) implantation. Patients and methods In this retrospective study, 782 eyes that underwent LVC to correct unintended ametropia after multifocal IOL implantation were evaluated. Of all multifocal lenses implanted during primary procedure, 98.7% were refractive and 1.3% had a diffractive design. All eyes were treated with VISX STAR S4 IR excimer laser using a convectional ablation profile. Refractive outcomes, visual acuities, patient satisfaction, and quality of life were evaluated at the last available visit. Results The mean time between enhancement and last visit was 6.3±4.4 months. Manifest spherical equivalent changed from −0.02±0.83 D (−3.38 D to +2.25 D) pre-enhancement to 0.00±0.34 D (−1.38 D to +1.25 D) post-enhancement. At the last follow-up, the percentage of eyes within 0.50 D and 1.00 D of emmetropia was 90.4% and 99.5%, respectively. Of all eyes, 74.9% achieved monocular uncorrected distance visual acuity 20/20 or better. The mean corrected distance visual acuity remained the same before (−0.04±0.06 logMAR [logarithm of the minimum angle of resolution]) and after LVC procedure (−0.04±0.07 logMAR; P=0.70). There was a slight improvement in visual phenomena (starburst, halo, glare, ghosting/double vision) following the enhancement. No sight-threatening complications related to LVC occurred in this study. Conclusion LVC in pseudophakic patients with multifocal IOL was safe, effective, and predictable in a large cohort of patients. PMID:27175059

  5. Hyperbranched Acrylated Aromatic Polyester Used as a Modifier in UV-Curable Epoxy Acrylate Resins

    Institute of Scientific and Technical Information of China (English)

    KOU,Hui-Guang; ASIF,Anila; SHI,Wen-Fang

    2003-01-01

    The viscosity, the shrinkage degree and the photoplymerization rate of the epoxy acrylate (EB600 ) blended with hyperbranched acrylated aromatic polyester ( HAAPE ) were investigated. The addition of HAAPE into EB600 largely reduces the viscosity of the blend formulation and the shrinkage degree. For example, EB600resin with 50% weight fraction of HAAPE has the 1250 cps of the viscosity and 2.0% of shrinkage degree, while the pure EB600 resin has 3000 cps of the viscosity and 10.5% of shrinkage degree. The photopolymerization rate of the rein is also promoted by HAAPE addition. The good miscibility between HAAPE and EB600 was also observed from the dynamic mechanical analysis. The tensile, flexural and compressive strength, and the thermal properties of the UVcured films are greatly improved.

  6. 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.

  7. 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 (2-HEMA

  8. PHOTOINITIATED INVERSE EMULSION POLYMERIZATION OF SODIUM ACRYLATE

    Institute of Scientific and Technical Information of China (English)

    Lian-ying Liu; Zhi-xing Zhang; Wan-tai Yang

    2005-01-01

    Photoinitiated inverse emulsion polymerization of sodium acrylate (AANa) in kerosene was carried out at room or lower temperature, using 2,2-dimethoxy-2-phenylacetophenone (DMPA) as the initiator. Kinetic investigations indicated that the polymerization could be completed in about 30 min and produce polymer with high molecular weight (106~107). It was found that monomer droplets are the main sites for the polymerization (nucleation). With the increase of DMPA concentration, polymerization rate (Rp) reaches a maximum value while molecular weight of the produced polymer has an adverse result, but the dependence of Rp on incident light intensity is similar. Influences of other parameters such as monomer concentration, emulsifier content and reaction temperature, etc. were also studied. At lower pH values of water phase, Rp depends strongly on the pH due to the electrostatic interaction between the ionized radicals and the monomer. At higher pH, Rp shows a slight dependence on pH.

  9. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  10. Foldable micro coils for a transponder system measuring intraocular pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ullerich, S.; Schnakenberg, U. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1; Mokwa, W. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1]|[Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany); Boegel, G. vom [Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany)

    2001-07-01

    A foldable transponder system consisting of a chip and a micro coil for measuring intraocular pressure continuously is presented. The system will be integrated in the haptic of a soft artificial intraocular lens. Calculations of planar micro coils with 6 mm and 10.3 mm in diameter show the limits for planar coils with an outer diameter of 6 mm. For the realisation of the transponder system a 20 {mu}m thick coil with an outer diameter of 10.3 mm, an inner diameter of 7.7 mm, 16 turns and a gap of 20 {mu}m between the windings was selected. Measurements show a good agreement between calculated and measured values. Wireless pressure measurements were carried out showing a linear behaviour of the output signal with respect to the applied pressure. (orig.)

  11. A CLINICAL STUDY OF INTRAOCULAR PRESSURE CHANGES WITH VECURONIUM BROMIDE AND PANCURONIUM BROMIDE

    Directory of Open Access Journals (Sweden)

    Nagaraja

    2014-04-01

    Full Text Available BACKGROUND: The maintenance of intraocular pressure forms the mainstay of anesthetic management of intraocular surgery. It is desirable to achieve a normal or reduced intraocular pressure before the eye is opened to avoid expulsive hemorrhage and ocular disruption at the time of incision. Therefore the ideal anesthetic technique for intraocular surgery should produce a moderate reduction in intraocular pressure, or maintain intraocular pressure at near normal values and avoid marked fluctuations during surgery (George et al, 1979. The use of suxamethonium is associated with significant rise in intraocular pressure with a peak increase between 2 and 4 minutes following administration and return to base line value after 6 minutes. The outcome of eye surgery, particularly when there is globe injury depends to a large extent on good control of intraocular pressure not only during maintenance, but also at induction of anesthesia. This is usually achieved by use of non-depolarizing muscle relaxant. Pancuronium when used in relatively larger doses is known to have a faster onset of action and also the block may be prolonged. Vecuronium is intermediate acting and free of cardiovascular and other side effects even when used in larger doses. ABACKGROUND: The maintenance of intraocular pressure forms the mainstay of anesthetic management of intraocular surgery. It is desirable to achieve a normal or reduced intraocular pressure before the eye is opened to avoid expulsive hemorrhage and ocular disruption at the time of incision. Therefore the ideal anesthetic technique for intraocular surgery should produce a moderate reduction in intraocular pressure, or maintain intraocular pressure at near normal values and avoid marked fluctuations during surgery (George et al, 1979. The use of suxamethonium is associated with significant rise in intraocular pressure with a peak increase between 2 and 4 minutes following administration and return to base line value

  12. 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.

  13. Intraocular Pressure Following Intravitreal Injection of Triamcinolone Acetonide§

    OpenAIRE

    Ansari, Ejaz A; Ali, N

    2008-01-01

    Background: To investigate the intraocular pressure (IOP) response following intravitreal injection of triamcinolone acetonide. Methods: This retrospective consecutive non-comparative case series study included 41 patients (52 eyes) (19 male, 22 female, mean age 64.1 ± 13.44; range 22 – 85 years) with progressive exudative ARMD (n = 10 eyes) or diffuse diabetic macular oedema (42 eyes), who received one or more intravitreal injection(s) of 4 mg triamcinolone acetonide. Results: IOP increased ...

  14. NANOTECHNOLOGY IN THE TREATMENT AND DETECTION OF INTRAOCULAR CANCERS

    OpenAIRE

    Nair, Ashwin; Thevenot, Paul; Hu, Wenjing; Tang, Liping

    2008-01-01

    Tremendous progress in nanotechnology has lead to the development of nanometer-sized objects as medical implants or devices. Many of these nanodevices have recently been tested in many cancer diagnostic and therapeutic applications, such as leukemia, melanoma, breast tumor, prostate tumor, and brain cancer. Despite the increasing importance of nanotechnology in cancer, the potential of these nanodevices in diagnosing and treating intraocular cancers has not been systematically evaluated. This...

  15. Intraocular Pressure And Its Determinants In Tehran Population

    OpenAIRE

    Kashi AH; Fotouhil A; Hashemi H.; Mohammadl K

    2005-01-01

    Background: The aim of this study was to provide data, on the distribution or intraocular pressure (IOP) in Tehran population. Materials and Methods: Through a population-based, cross-sectional study, a total of 4565 Tehran citizens were studied in the Tehran Eye Study. The findings of the participants (n=3834) 10 years and older free of glaucoma diagnosis or suspicion who had undergone applanation tonometry examination are presented. All participants received a standardized protocol included...

  16. Black intraocular lens: another cosmetic approach to leukocoria

    OpenAIRE

    Pedrosa, C; Pina, S.; Azevedo, A.; Pêgo, P; Feijóo, B; Prieto, I

    2012-01-01

    Purpose – To present a case report of a black intraocular lens implantation for cosmetic improvement of a blind eye with leukocoria. Setting – Ophthalmology Department - Professor Dr. Fernando Fonseca Hospital, EPE - Amadora, Lisboa, Portugal Methods – We report a 32-year-old woman who was evaluated because of the undesired cosmetic appearance of her amblyopic left eye with exotropia and leukocoria due to traumatic cataract and total retinal detachment during childhood. The Examination ...

  17. Increased Intraocular Pressure after Extensive Conjunctival Removal: A Case Report

    OpenAIRE

    Lee, Young Rok; Na, Jung Hwa; Kim, Jae Yong; Sung, Kyung Rim

    2013-01-01

    A 50-year-old woman, who had undergone extensive removal of conjunctiva on the right eye for cosmetic purposes at a local clinic 8 months prior to presentation, was referred for uncontrolled intraocular pressure (IOP) elevation (up to 38 mmHg) despite maximal medical treatment. The superior and inferior conjunctival and episcleral vessels were severely engorged and the nasal and temporal bulbar conjunctival areas were covered with an avascular epithelium. Gonioscopic examination revealed an o...

  18. Intraocular gnathostomiasis: A rare case report from Central India

    Science.gov (United States)

    Rawat, Preeti; Gautam, Manushree; Jain, Nikhila C; Jain, Rajdeep

    2016-01-01

    We report the first case of intraocular gnathostomiasis from Central India. A 29-year-old male from Indore, Madhya Pradesh, presented with pain and redness of the right eye since 1 month. Slit lamp examination revealed anterior uveitis, multiple iris atrophic patches, and a live worm hooked on iris. The worm was removed through a small sclerocorneal tunnel. Microscopy confirmed Gnathostoma spinigerum. The patient was treated with oral albendazole and steroids. The case is reported because of its rarity. PMID:27146938

  19. Visual functional changes during acute elevation of intraocular pressure

    Institute of Scientific and Technical Information of China (English)

    Tian-De SHOU

    2006-01-01

    Glaucoma is closely related to elevation of intraocular pressure (IOP). Many studies have done on the effect of chronic elevation of IOP on the retina and optic nerve, but less attention was paid to the effect of acute elevated IOP. Here we briefly review experimental studies on functional changes of the visual system from the retina to the visual cortex under acute elevated IOP condition, which is similar to that of acute primary angle-closure glaucoma.

  20. CMB-lensing beyond the Born approximation

    Science.gov (United States)

    Marozzi, Giovanni; Fanizza, Giuseppe; Di Dio, Enea; Durrer, Ruth

    2016-09-01

    We investigate the weak lensing corrections to the cosmic microwave background temperature anisotropies considering effects beyond the Born approximation. To this aim, we use the small deflection angle approximation, to connect the lensed and unlensed power spectra, via expressions for the deflection angles up to third order in the gravitational potential. While the small deflection angle approximation has the drawback to be reliable only for multipoles l lesssim 2500, it allows us to consistently take into account the non-Gaussian nature of cosmological perturbation theory beyond the linear level. The contribution to the lensed temperature power spectrum coming from the non-Gaussian nature of the deflection angle at higher order is a new effect which has not been taken into account in the literature so far. It turns out to be the leading contribution among the post-Born lensing corrections. On the other hand, the effect is smaller than corrections coming from non-linearities in the matter power spectrum, and its imprint on CMB lensing is too small to be seen in present experiments.

  1. Successful Removal of Large Intraocular Foreign Body by 25-Gauge Microincision Vitrectomy Surgery

    OpenAIRE

    Hiroshi Kunikata; Megumi Uematsu; Toru Nakazawa; Nobuo Fuse

    2011-01-01

    We describe a new technique for removing a large intraocular foreign body by 25-gauge microincision vitrectomy surgery (25G-MIVS). Noncomparative interventional case series were performed at a single centre. Two patients with a long smooth intraocular vitreal foreign body underwent phacoemulsification and aspiration, intraocular lens implantation, 25G-MIVS, and extraction of the foreign body. The foreign body was removed through a posterior capsulorhexis, anterior continuous curvilinear capsu...

  2. Effects of Mirtogenol® on ocular blood flow and intraocular hypertension in asymptomatic subjects

    OpenAIRE

    Steigerwalt, Robert D; Gianni, Belcaro; Paolo, Morazzoni; Bombardelli, Ezio; Burki, Carolina; Schönlau, Frank

    2008-01-01

    Purpose The most important variable risk factor for developing glaucoma is intraocular hypertension. Timely lowering of high intraocular pressure (IOP) significantly lowers the likelihood of developing glaucoma. The aim of this study was to evaluate the effects of the food supplement Mirtogenol® (Mirtoselect® and Pycnogenol®) on IOP and ocular blood flow in a product evaluation study. Methods Thirty-eight asymptomatic subjects with intraocular hypertension were either given Mirtogenol® (20 su...

  3. Posterior chamber phakic intraocular lens implantation for high myopia

    Institute of Scientific and Technical Information of China (English)

    沈晔; 杜持新; 顾扬顺; 王竞

    2003-01-01

    Objective To evaluate the efficacy, safety and stability of posterior chamber phakic intraocular lens (PIOLs) implantation for the correction of high myopia.Methods Thirty-nine eyes of twenty patients with high myopia (between-11.75 and-25.75 diopters) had a posterior chamber PIOL (Staar ICL) implanted. During 6-48 months' follow-up, visual acuity, refraction, intraocular pressure (IOP), corneal reaction and space between crystal lens and intraocular lens (IOLs) were tested.Results Successful implantation was achieved in all patients. Visual acuity without correction greater than 0.5 was found in 34 eyes at 1 day and 3 months postoperatively. Thirty-five eyes maintained a low negative power of refraction (-1.42±1.32 doipters), which did not prevent the patients from most of their daily activities. During 3-48 months' follow-up, refraction was stable and no cornea edema and glaucoma was found. Two eyes of one patient had corticosteroid glaucoma and another eye showed cataractogenesis under anterior capsular membrane.Conclusion Posterior chamber PIOL implantation is predictable, safe, and effective in the correction of high myopia, and its indications should be carefully selected.

  4. Removal of Intralenticular Magnetic Foreign Bodies with Intraocular Magnet

    Institute of Scientific and Technical Information of China (English)

    Yiwen Luo; Zhenfang Wang; Xiaofeng Lin; Shuying Hu

    2003-01-01

    Purpose: To investigate the possibility of conservation of the lens after removal of intralenticular magnetic foreign bodies with intraocular magnet.Methods: Intralenticular magnetic foreign bodies of 15 patients were removed by using an intraocular magnet. The lens of each injury eye was conserved. Follow-up observation of these cases ranged from one to four years.Results: The intralenticular magnetic foreign bodies of 15 patients were successfully removed.The lens of each injury eye was conserved and the transparence of the lens was properly maintained. Sizes of these foreign bodies were measured, ranging from 0.3 mm to 3mm in diameter. The follow-up observation showed that the corrected visual acuity of 14 cases was not changed after operation.Conclusions: The intraocular magnet is very helpful for removal of magnetic foreign bodies from the transparent lens. This magnet allows removing of the foreign body by the surgeon and no damage to the lens was induced during the operation. Thus, maintenance of visual acuity of most of the patients can be achieved.

  5. COMPLEX OXIDE CATALYSTS OF ACRYLIC ACID OBTAINING BY ALDOL CONDENSATION METHOD

    OpenAIRE

    Nebesnyi, R.

    2015-01-01

    The present work is dedicated to solving the problem of diversification of the raw materials base for acrylate monomers obtaining,  first of all acrylic acid. Acrylic acid and its derivatives are bulk products of organic synthesis with a wide range of applications. The main industrial method of acrylic acid production is  propylene oxidation. But this method has instable economic indicators as propylene is petroleum origin raw material.It is possible to expand the resource base of acrylic aci...

  6. Keeping an eye on dialysis: the association of hemodialysis with intraocular hypertension.

    Science.gov (United States)

    William, Jeffrey H; Gilbert, Aubrey L; Rosas, Sylvia E

    2015-11-01

    Intraocular hypertension is common during hemodialysis. Dialysis disequilibrium syndrome and intraocular hypertension occur via similar pathophysiologic mechanisms. These mechanisms may contribute to the development of glaucoma and cataracts in a patient population already at high risk for ocular abnormalities, given the common risk factors for chronic kidney disease and impaired aqueous humor outflow. We describe a patient with complicated diabetes mellitus, end-stage renal disease, and recent cataract surgery who developed severe intraocular hypertension during hemodialysis. We recommend increased awareness of the symptoms of intraocular hypertension and subsequent ophthalmologic surveillance in order to prevent long-term visual complications. PMID:26042412

  7. HerMES: Candidate Gravitationally Lensed Galaxies and Lensing Statistics at Submillimeter Wavelengths

    CERN Document Server

    Wardlow, Julie L; De Bernardis, Francesco; Amblard, A; Arumugam, V; Aussel, H; Baker, A J; Béthermin, M; Blundell, R; Bock, J; Boselli, A; Bridge, C; Buat, V; Burgarella, D; Bussmann, R S; Calanog, J; Carpenter, J M; Casey, C M; Castro-Rodríguez, N; Cava, A; Chanial, P; Chapman, S C; Clements, D L; Conley, A; Cox, P; Dowell, C D; Dye, S; Eales, S; Farrah, D; Franceschini, A; Frayer, D T; Frazer, C; Fu, Hai; Gavazzi, R; Glenn, J; Griffin, M; Gurwell, M A; Harris, A I; Hatziminaoglou, E; Hopwood, R; Ibar, E; Ivison, R J; Kim, S; Lagache, G; Levenson, L; Marchetti, L; Marsden, G; Negrello, M; Neri, R; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Page, M J; Panuzzo, P; Papageorgiou, A; Pearson, C P; Pérez-Fournon, I; Pohlen, M; Riechers, D; Rigopoulou, D; Roseboom, I G; Rowan-Robinson, M; Schulz, B; Scott, D; Scoville, N; Seymour, N; Shupe, D L; Smith, A J; Symeonidis, M; Trichas, M; Vaccari, M; Vieira, J D; Viero, M; Wang, L; Xu, C K; Yan, L; Zemcov, M

    2012-01-01

    We present a list of 13 candidate gravitationally lensed submillimeter galaxies (SMGs) from 95 square degrees of the Herschel Multi-tiered Extragalactic Survey, a surface density of 0.14\\pm0.04deg^{-2}. These sources have 500um flux densities (S_500) greater than 100mJy. Follow-up observations confirm gravitational lensing in 9 of the 13 systems (70%); the lensing status of the four remaining sources is undetermined. We also present a supplementary sample of 29 (0.31\\pm0.06deg^{-2}) gravitationally lensed SMG candidates with S_500=80--100mJy, which are expected to contain a higher fraction of interlopers than the primary candidates. The number counts of the candidate lensed galaxies are consistent with a simple statistical model of the lensing rate, which uses a foreground matter distribution, the intrinsic SMG number counts, and an assumed SMG redshift distribution. The model predicts that 43--83% of our S_500>100mJy candidates are strongly gravitationally lensed, with the brightest sources being the most ro...

  8. [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)

  9. Weak lensing in the Dark Energy Survey

    Science.gov (United States)

    Troxel, Michael

    2016-03-01

    I will present the current status of weak lensing results from the Dark Energy Survey (DES). DES will survey 5000 square degrees in five photometric bands (grizY), and has already provided a competitive weak lensing catalog from Science Verification data covering just 3% of the final survey footprint. I will summarize the status of shear catalog production using observations from the first year of the survey and discuss recent weak lensing science results from DES. Finally, I will report on the outlook for future cosmological analyses in DES including the two-point cosmic shear correlation function and discuss challenges that DES and future surveys will face in achieving a control of systematics that allows us to take full advantage of the available statistical power of our shear catalogs.

  10. Electron lenses for super-colliders

    CERN Document Server

    Shiltsev, Vladimir D

    2016-01-01

    This book provides a comprehensive overview of the operating principles and technology of electron lenses in supercolliders.  Electron lenses are a novel instrument for high energy particle accelerators, particularly for the energy-frontier superconducting hadron colliders, including the Tevatron, RHIC, LHC and future very large hadron colliders.  After reviewing the issues surrounding beam dynamics in supercolliders, the book offers an introduction to the electron lens method and its application.  Further chapters describe the technology behind the electron lenses which have recently been proposed, built and employed for compensation of beam-beam effects and for collimation of high-energy high-intensity beams, for compensation of space-charge effects and several other applications in accelerators. The book will be an invaluable resource for those involved in the design, construction and operation of the next generation of hadron colliders.

  11. Gravitational Lensing from a Spacetime Perspective

    Directory of Open Access Journals (Sweden)

    Perlick Volker

    2004-09-01

    Full Text Available The theory of gravitational lensing is reviewed from a spacetime perspective, without quasi-Newtonian approximations. More precisely, the review covers all aspects of gravitational lensing where light propagation is described in terms of lightlike geodesics of a metric of Lorentzian signature. It includes the basic equations and the relevant techniques for calculating the position, the shape, and the brightness of images in an arbitrary general-relativistic spacetime. It also includes general theorems on the classification of caustics, on criteria for multiple imaging, and on the possible number of images. The general results are illustrated with examples of spacetimes where the lensing features can be explicitly calculated, including the Schwarzschild spacetime, the Kerr spacetime, the spacetime of a straight string, plane gravitational waves, and others.

  12. Cluster mass reconstruction from weak gravitational lensing

    CERN Document Server

    Wilson, G; Frenk, C S; Wilson, Gillian; Cole, Shaun; Frenk, Carlos S

    1996-01-01

    Kaiser & Squires have proposed a technique for mapping the dark matter in galaxy clusters using the coherent weak distortion of background galaxy images caused by gravitational lensing. We investigate the effectiveness of this technique under controlled conditions by creating simulated CCD frames containing galaxies lensed by a model cluster, measuring the resulting galaxy shapes, and comparing the reconstructed mass distribution with the original. Typically, the reconstructed surface density is diminished in magnitude when compared to the original. The main cause of this reduced signal is the blurring of galaxy images by atmospheric seeing, but the overall factor by which the reconstructed surface density is reduced depends also on the signal-to-noise ratio in the CCD frame and on both the sizes of galaxy images and the magnitude limit of the sample that is analysed. We propose a method for estimating a multiplicative compensation factor. We test our technique using a lensing cluster drawn from a cosmolo...

  13. Orbital Motion During Gravitational Lensing Events

    CERN Document Server

    Di Stefano, Rosanne

    2014-01-01

    Gravitational lensing events provide unique opportunities to discover and study planetary systems and binaries. Here we build on previous work to explore the role that orbital motion can play in both identifying and learning more about multiple-mass systems that serve as gravitational lenses. We find that a significant fraction of planet-lens and binary-lens light curves are influenced by orbital motion. Furthermore, the effects of orbital motion extend the range of binaries for which lens multiplicity can be discovered and studied. Orbital motion will play an increasingly important role as observations with sensitive photometry, such as those made by the space missions Kepler, Transiting Exoplanet Survey Satellite, (TESS), and WFIRST discover gravitational lensing events. Similarly, the excellent astrometric measurements made possible by GAIA will allow it to study the effects of orbital motion. Frequent observations, such as those made possible with the Korean Microlensing Telescope Network, KMTNet, will al...

  14. The conceptual origins of gravitational lensing

    CERN Document Server

    Valls-Gabaud, David

    2012-01-01

    We critically examine the evidence available of the early ideas on the bending of light due to a gravitational attraction, which led to the concept of gravitational lenses, and attempt to present an undistorted historical perspective. Contrary to a widespread but baseless claim, Newton was not the precursor to the idea, and the first Query in his {\\sl Opticks} is totally unrelated to this phenomenon. We briefly review the roles of Voltaire, Marat, Cavendish, Soldner and Einstein in their attempts to quantify the gravitational deflection of light. The first, but unpublished, calculations of the lensing effect produced by this deflection are found in Einstein's 1912 notebooks, where he derived the lensing equation and the formation of images in a gravitational lens. The brief 1924 paper by Chwolson which presents, without calculations, the formation of double images and rings by a gravitational lens passed mostly unnoticed. The unjustly forgotten and true pioneer of the subject is F. Link, who not only publishe...

  15. Weak Lensing with Radio Continuum Surveys

    CERN Document Server

    Patel, Prina

    2016-01-01

    Weak gravitational lensing is a powerful probe of cosmology and has emerged as a key probe for the Dark Universe. Up till now this science has been conducted mainly at optical wavelengths. Current upgraded and future radio facilities will provide greatly improved data that will allow lensing measurements to be made at these longer wavelengths. In this proceedings I show how the larger facilities such as the SKA can produce game changing cosmological measurements even compared to future optical telescopes. I will also discuss how radio surveys can also provide unique ways in which some of the most problematic systematic errors can be mitigated through the extra information that can be provided in the form of polarisation and rotational velocity measurements. I will also demonstrate the advantages to having overlapping optical and radio weak lensing surveys and how their cross-correlation leads to a cleaner extraction of the cosmological information. Key to the realisation of the great promise of radio weak len...

  16. Trapping light by mimicking gravitational lensing

    CERN Document Server

    Sheng, C; Wang, Y; Zhu, S N; Genov, D A

    2013-01-01

    One of the most fascinating predictions of the theory of general relativity is the effect of gravitational lensing, the bending of light in close proximity to massive stellar objects. Recently, artificial optical materials have been proposed to study the various aspects of curved spacetimes, including light trapping and Hawking's radiation. However, the development of experimental toy models that simulate gravitational lensing in curved spacetimes remains a challenge, especially for visible light. Here, by utilizing a microstructured optical waveguide around a microsphere, we propose to mimic curved spacetimes caused by gravity, with high precision. We experimentally demonstrate both far-field gravitational lensing effects and the critical phenomenon in close proximity to the photon sphere of astrophysical objects under hydrostatic equilibrium. The proposed microstructured waveguide can be used as an omnidirectional absorber, with potential light harvesting and microcavity applications.

  17. PICS: Simulations of Strong Gravitational Lensing in Galaxy Clusters

    CERN Document Server

    Li, Nan; Rangel, Esteban M; Florian, Michael K; Bleem, Lindsey E; Heitmann, Katrin; Habib, Salman; Fasel, Patricia

    2015-01-01

    Gravitational lensing has become one of the most powerful tools available for investigating the 'dark side' of the universe. Cosmological strong gravitational lensing, in particular, probes the properties of the dense cores of dark matter halos over decades in mass and offers the opportunity to study the distant universe at flux levels and spatial resolutions otherwise unavailable. Studies of strongly-lensed variable sources offer yet further scientific opportunities. One of the challenges in realizing the potential of strong lensing is to understand the statistical context of both the individual systems that receive extensive follow-up study, as well as that of the larger samples of strong lenses that are now emerging from survey efforts. Motivated by these challenges, we have developed an image-simulation pipeline, PICS (Pipeline for Images of Cosmological Strong lensing) to generate realistic strong gravitational lensing signals from group and cluster scale lenses. PICS uses a low-noise and unbiased densit...

  18. Baryons, neutrinos, feedback and weak gravitational lensing

    Science.gov (United States)

    Harnois-Déraps, Joachim; van Waerbeke, Ludovic; Viola, Massimo; Heymans, Catherine

    2015-06-01

    The effect of baryonic feedback on the dark matter mass distribution is generally considered to be a nuisance to weak gravitational lensing. Measurements of cosmological parameters are affected as feedback alters the cosmic shear signal on angular scales smaller than a few arcminutes. Recent progress on the numerical modelling of baryon physics has shown that this effect could be so large that, rather than being a nuisance, the effect can be constrained with current weak lensing surveys, hence providing an alternative astrophysical insight on one of the most challenging questions of galaxy formation. In order to perform our analysis, we construct an analytic fitting formula that describes the effect of the baryons on the mass power spectrum. This fitting formula is based on three scenarios of the OverWhelmingly Large hydrodynamical simulations. It is specifically calibrated for z lensing data, from the Canada France Hawaii Telescope Lensing Survey (CFHTLenS). In this analysis, we show that the effect of neutrino mass on the mass power spectrum is degenerate with the baryonic feedback at small angular scales and cannot be ignored. Assuming a cosmology precision fixed by WMAP9, we find that a universe with massless neutrinos is rejected by the CFHTLenS lensing data with 85-98 per cent confidence, depending on the baryon feedback model. Some combinations of feedback and non-zero neutrino masses are also disfavoured by the data, although it is not yet possible to isolate a unique neutrino mass and feedback model. Our study shows that ongoing weak gravitational lensing surveys (KiDS, HSC and DES) will offer a unique opportunity to probe the physics of baryons at galactic scales, in addition to the expected constraints on the total neutrino mass.

  19. Performance behavior of modified cellulosic fabrics using polyurethane acrylate copolymer.

    Science.gov (United States)

    Zuber, Mohammad; Shah, Sayyed Asim Ali; Jamil, Tahir; Asghar, Muhammad Irfan

    2014-06-01

    The surface of the cellulosic fabrics was modified using self-prepared emulsions of polyurethane acrylate copolymers (PUACs). PUACs were prepared by varying the molecular weight of polycaprolactone diol (PCL). The PCL was reacted with isophorone diisocyanate (IPDI) and chain was extended with 2-hydroxy ethyl acrylate (HEA) to form vinyl terminated polyurethane (VTPU) preploymer. The VTPU was further co-polymerized through free radical polymerization with butyl acrylate in different proportions. The FT-IR spectra of monomers, prepolymers and copolymers assured the formation of proposed PUACs structure. The various concentrations of prepared PUACs were applied onto the different fabric samples using dip-padding techniques. The results revealed that the application of polyurethane butyl acrylate copolymer showed a pronounced effect on the tear strength and pilling resistance of the treated fabrics.

  20. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    Directory of Open Access Journals (Sweden)

    U. Akhmedov

    2012-09-01

    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.