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Sample records for acrylic intraocular lenses

  1. Laboratory analyses of two explanted hydrophobic acrylic intraocular lenses

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

    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.

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

    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.

  4. Late opacification of a hydrophilic acrylic intraocular lens

    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.

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

    Ladan Espandar

    2011-01-01

    Full Text Available 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 lens (IOL. The hydrophilic design of the lens is optimized to address dysphotopsia while maintaining biocompatibility, optical clarity, resistance to damage, and resistance to biocontamination. Aspheric lenses decrease postoperative spherical aberration. The addition of the Softec lens provides clinicians with another option for IOL placement; however, randomized comparative studies of this lens to others already on the market remain to be completed.Keywords: hydrophilic acrylic intraocular lens, Softec HD intraocular lens, aspheric intraocular lens, IOL

  6. Analytical design of intraocular lenses

    Barbero Briones, Sergio; Marcos Celestino, Susana; Dorronsoro Díaz, Carlos

    2008-01-01

    The invention relates to a method for designing intraocular lenses, comprising: the definition of a pseudoaphakic eye model; the definition of a merit function in multiple dimensions, which analytically connects the quality of the image on the retina to the optical and geometric parameters of the pseudoaphakic eye model; and the algorithm optimisation of the previous merit function using analytical and numerical methods in order to obtain one or more minimum globals which provide the optimal ...

  7. Developments in Accommodating Intraocular Lenses

    Zeki Tunç

    2012-07-01

    Full Text Available Technical progress in cataract surgery has decreased the incidence of severe complications in this type of surgery. The introduction of micro incision cataract surgery (MICS (sub- 2.0 mm incision allow the surgeon to achieve better postoperative control of astigmatism and higherorder aberration (HOAs with minimum induction of both. It is believed that multifocal lenses provide very successful results, however, there are limitations to these. Implantation of accommodating intraocular lenses (IOLs is an option to treat presbyopia. The IOLs work by using the continued functionality of the ciliary muscle after cataract removal. Accommodating IOLs were designed to avoid the optical side effects of multifocal IOLs. Two main design concepts exist. First, axial shift concepts rely on anterior axial movement of one or two optics creating accommodative ability. Second, curvature change designs are designed to provide significant amplitudes of accommodation with little physical displacement. Accommodative IOLs to correct astigmatism and HOAs in the future are needed. (Turk J Ophthalmol 2012; 42: 288-93

  8. Surface Modification of Intraocular Lenses

    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.

  9. Surface Modification of Intraocular Lenses

    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.

  10. DESIGN OF THE MULTIORDER INTRAOCULAR LENSES

    V. G. Kolobrodov

    2015-12-01

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

  11. Adherence of Staphylococcus epidermidis to intraocular lenses.

    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...

  12. File list: DNS.Oth.05.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available DNS.Oth.05.AllAg.Lenses,_Intraocular mm9 DNase-seq Others Lenses, Intraocular http:...//dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Oth.05.AllAg.Lenses,_Intraocular.bed ...

  13. File list: DNS.Oth.10.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available DNS.Oth.10.AllAg.Lenses,_Intraocular mm9 DNase-seq Others Lenses, Intraocular http:...//dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Oth.10.AllAg.Lenses,_Intraocular.bed ...

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

    Full Text Available DNS.Oth.20.AllAg.Lenses,_Intraocular mm9 DNase-seq Others Lenses, Intraocular http:...//dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  15. File list: DNS.Oth.50.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available DNS.Oth.50.AllAg.Lenses,_Intraocular mm9 DNase-seq Others Lenses, Intraocular http:...//dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Oth.50.AllAg.Lenses,_Intraocular.bed ...

  16. Drug-Eluting Intraocular Lenses

    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.

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

    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. Evaluating the method increasing of toric intraocular lenses rotational stability

    G. A. Fedjashev

    2015-01-01

    Purpose. To suggest a safe and effective way to improve the rotational stability of the position of toric the intraocular lenses in the capsular bag.Patients and methods.86 patients (97 eyes) with corneal astigmatism undergoing cataract surgery and Acrysof Toric (Alcon, USA) intraocular lens implantation. In 42 patients (47 eyes), the intraocular lens (IOL) were implanted in accordance with the proposed invention.Results. Average rotation angle IOL implanted by traditional technology was 2,2±...

  19. Corrigendum: Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    Espandar L

    2011-02-01

    Full Text Available Espandar L, Sikder S, Moshirfar M. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision. Clin Ophthalmol. 2011;5:65–70.There was an error in the reported optic size of Lenstec’s Softec HD intraocular lens, which was reported to be 5.5 mm in Espandar et al’s work, but is 5.75 mm.Please see the specifications on Lenstec’s Web site for further details (see http://www.lenstec.com/lenstec/hd_specs.html.Read the original article

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

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

  1. File list: Pol.Oth.50.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Pol.Oth.50.AllAg.Lenses,_Intraocular mm9 RNA polymerase Others Lenses, Intraocular ...SRX957689 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Oth.50.AllAg.Lenses,_Intraocular.bed ...

  2. File list: InP.Oth.05.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available InP.Oth.05.AllAg.Lenses,_Intraocular mm9 Input control Others Lenses, Intraocular S...RX957681,SRX957691,SRX957693 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Oth.05.AllAg.Lenses,_Intraocular.bed ...

  3. File list: Oth.Oth.50.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Oth.Oth.50.AllAg.Lenses,_Intraocular mm9 TFs and others Others Lenses, Intraocular ...SRX957680 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Oth.50.AllAg.Lenses,_Intraocular.bed ...

  4. File list: Unc.Oth.20.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Unc.Oth.20.AllAg.Lenses,_Intraocular mm9 Unclassified Others Lenses, Intraocular SR...X1127448 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  5. File list: His.Oth.50.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available His.Oth.50.AllAg.Lenses,_Intraocular mm9 Histone Others Lenses, Intraocular SRX9576...85,SRX957687,SRX957683,SRX957695 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Oth.50.AllAg.Lenses,_Intraocular.bed ...

  6. File list: Pol.Oth.05.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Pol.Oth.05.AllAg.Lenses,_Intraocular mm9 RNA polymerase Others Lenses, Intraocular ...SRX957689 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Oth.05.AllAg.Lenses,_Intraocular.bed ...

  7. File list: InP.Oth.20.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available InP.Oth.20.AllAg.Lenses,_Intraocular mm9 Input control Others Lenses, Intraocular S...RX957681,SRX957691,SRX957693 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  8. File list: NoD.Oth.20.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available NoD.Oth.20.AllAg.Lenses,_Intraocular mm9 No description Others Lenses, Intraocular ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  9. File list: His.Oth.20.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available His.Oth.20.AllAg.Lenses,_Intraocular mm9 Histone Others Lenses, Intraocular SRX9576...85,SRX957687,SRX957695,SRX957683 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  10. File list: Unc.Oth.50.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Unc.Oth.50.AllAg.Lenses,_Intraocular mm9 Unclassified Others Lenses, Intraocular SR...X1127448 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.50.AllAg.Lenses,_Intraocular.bed ...

  11. File list: Unc.Oth.05.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Unc.Oth.05.AllAg.Lenses,_Intraocular mm9 Unclassified Others Lenses, Intraocular SR...X1127448 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Oth.05.AllAg.Lenses,_Intraocular.bed ...

  12. File list: InP.Oth.10.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available InP.Oth.10.AllAg.Lenses,_Intraocular mm9 Input control Others Lenses, Intraocular S...RX957681,SRX957691,SRX957693 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Oth.10.AllAg.Lenses,_Intraocular.bed ...

  13. File list: Oth.Oth.10.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Oth.Oth.10.AllAg.Lenses,_Intraocular mm9 TFs and others Others Lenses, Intraocular ...SRX957680 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Oth.10.AllAg.Lenses,_Intraocular.bed ...

  14. File list: NoD.Oth.10.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available NoD.Oth.10.AllAg.Lenses,_Intraocular mm9 No description Others Lenses, Intraocular ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Oth.10.AllAg.Lenses,_Intraocular.bed ...

  15. File list: NoD.Oth.05.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available NoD.Oth.05.AllAg.Lenses,_Intraocular mm9 No description Others Lenses, Intraocular ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Oth.05.AllAg.Lenses,_Intraocular.bed ...

  16. File list: NoD.Oth.50.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available NoD.Oth.50.AllAg.Lenses,_Intraocular mm9 No description Others Lenses, Intraocular ...http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Oth.50.AllAg.Lenses,_Intraocular.bed ...

  17. File list: Pol.Oth.20.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Pol.Oth.20.AllAg.Lenses,_Intraocular mm9 RNA polymerase Others Lenses, Intraocular ...SRX957689 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  18. File list: Pol.Oth.10.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Pol.Oth.10.AllAg.Lenses,_Intraocular mm9 RNA polymerase Others Lenses, Intraocular ...SRX957689 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Oth.10.AllAg.Lenses,_Intraocular.bed ...

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

    Full Text Available Oth.Oth.20.AllAg.Lenses,_Intraocular mm9 TFs and others Others Lenses, Intraocular ...SRX957680 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Oth.20.AllAg.Lenses,_Intraocular.bed ...

  20. File list: Oth.Oth.05.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available Oth.Oth.05.AllAg.Lenses,_Intraocular mm9 TFs and others Others Lenses, Intraocular ...SRX957680 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Oth.05.AllAg.Lenses,_Intraocular.bed ...

  1. File list: His.Oth.10.AllAg.Lenses,_Intraocular [Chip-atlas[Archive

    Full Text Available His.Oth.10.AllAg.Lenses,_Intraocular mm9 Histone Others Lenses, Intraocular SRX9576...85,SRX957687,SRX957695,SRX957683 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Oth.10.AllAg.Lenses,_Intraocular.bed ...

  2. The dangers of metal-loop intraocular lenses.

    Shepard, D D

    1977-10-01

    The author implanted 500 intraocular lenses (IOLs) during intracapsular surgery. Data from the 60 lenses with metal posterior loops showed a markedly high incidence of complication compared to plastic loops: twice as many overall complications, three times the cystoid mascular edema, three times the rate for subsequent corrective surgical procedures, and 30 times more IOLs had to be removed. IOL manufacturers are advised to abandon metal loops for intracapsular implantation. Polypropylene is suggested as the apparent ideal loop material. PMID:304550

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

    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.

  4. Antireflection coatings for intraocular lenses of sapphire and fianite

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

  5. Pseudoexfoliation material on posterior chamber intraocular lenses

    Rocha-Bastos RA; Silva SE; Prézia F; Falcão-Reis F; Melo AB

    2014-01-01

    Ricardo António da Rocha-Bastos,1 Sérgio Estrela Silva,1 Flávio Prézia,1 Fernando Falcão-Reis,1,2 António B Melo11Department of Ophthalmology, Hospital São João, Alameda Prof Hernâni Monteiro, Porto, Portugal; 2Department of Sense Organs, Faculty of Medicine, University of Porto, Alameda Prof Hernâni Monteiro, Porto, PortugalAbstract: The presence of pseudoexfoliation material on the surface of an intraocular lens (IOL) is a ...

  6. Surgical management of astigmatism with toric intraocular lenses

    Ventura, Bruna V.; Li Wang; Weikert, Mitchell P.; Shaun B. Robinson; Koch, Douglas D.

    2014-01-01

    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...

  7. Single-optic positional accommodating intraocular lenses: a review

    Tomás Juan, Javier; Piñero Llorens, David Pablo; Larrañaga Murueta-Goyena, Ane

    2014-01-01

    Presbyopia is an age-related physiological condition that causes a gradual loss in the ability to focus on near objects, secondary to changes in zonular fibers, ciliary muscle and crystalline lens. Different surgical approaches are being pursued to surgically compensate presbyopia, such as corneal techniques or implantation of multifocal intraocular lenses (IOLs); however, their inability to restore accommodation has led to the development of single-optic positional accommodative IOLs. The ax...

  8. Pseudoexfoliation material on posterior chamber intraocular lenses

    Rocha-Bastos RA

    2014-08-01

    Full Text Available Ricardo António da Rocha-Bastos,1 Sérgio Estrela Silva,1 Flávio Prézia,1 Fernando Falcão-Reis,1,2 António B Melo11Department of Ophthalmology, Hospital São João, Alameda Prof Hernâni Monteiro, Porto, Portugal; 2Department of Sense Organs, Faculty of Medicine, University of Porto, Alameda Prof Hernâni Monteiro, Porto, PortugalAbstract: The presence of pseudoexfoliation material on the surface of an intraocular lens (IOL is a rare finding. We report a series of seven cases with different patterns of pseudoexfoliation material deposition on the posterior chamber IOLs, recognized 2–20 years after cataract surgery. Six patients had an IOL implanted in the capsular bag and one in the ciliary sulcus. Two patients had undergone posterior capsulotomy. Although the pathophysiological mechanisms and clinical significance of this finding remain unknown, the careful follow-up of pseudophakic patients with known or suspected pseudoexfoliation syndrome is essential to monitor the development or progression of glaucoma, since deposition of pseudoexfoliation material continues even after cataract surgery.Keywords: intraocular lens, glaucoma, exfoliation syndrome, cataract

  9. Standardized methods for assessing the imaging quality of intraocular lenses

    Norrby, N. E. Sverker

    1995-11-01

    The relative merits of three standardized methods for assessing the imaging quality of intraocular lenses are discussed based on theoretical modulation-transfer-function calculations. The standards are ANSI Z80.7 1984 from the American National Standards Institute, now superseded by ANSI Z80.7 1994, and the proposed ISO 11979-2 from the International Organization for Standardization. They entail different test 60% resolution efficiency in air, 70% resolutionefficiency in aqueous humor, and 0.43 modulation at 100 line pairs/mm in a model eye. The ISO working group found that the latter corresponds to 60% resolution efficiency in air in a ring test among eight laboratories on a sample of 39 poly(methyl) methacrylate lenses and four silicone lenses spanning the power (in aqueous humor) range of 10-30 D. In both ANSI Z80.7 1994 and ISO 11979-2, a 60% resolution efficiency in air remains an optional approval limit. It is concluded that the ISO configuration is preferred, because it puts the intraocular lens into the context of the optics of the eye. Note that the ISO standard is tentative and is currently being voted on.

  10. Evaluating the method increasing of toric intraocular lenses rotational stability

    G. A. Fedjashev

    2015-10-01

    Full Text Available Purpose. To suggest a safe and effective way to improve the rotational stability of the position of toric the intraocular lenses in the capsular bag.Patients and methods.86 patients (97 eyes with corneal astigmatism undergoing cataract surgery and Acrysof Toric (Alcon, USA intraocular lens implantation. In 42 patients (47 eyes, the intraocular lens (IOL were implanted in accordance with the proposed invention.Results. Average rotation angle IOL implanted by traditional technology was 2,2±2,0 degrees during 12 months. In patients with IOL implanted by the proposed method, the average angle of rotation of the IOL in all operated eyes was significantly lower and amounted to 0,8±1,2 degrees (p <0,05. Сonclusion. The proposed method of fixing the toric IOL provides for prevention the IOL rotation and decentration relative to the eye optical axis, take steps to prevent phimosis anterior lens capsule, maintaining high visual function for a long time, and as there is no need for repeated surgery.

  11. Intraocular lenses and clinical treatment in paediatric cataract

    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.

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

    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

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

    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 investigated in order to get a better understanding of the interactions between eye and intraocular lens. This thesis is divided into a first part covering animal experiments and a second part about m...

  14. The effect of ionizing radiation on intraocular lenses

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

  15. Comparative visual performance with monofocal and multifocal intraocular lenses

    Gundersen KG

    2013-10-01

    Full Text Available Kjell Gunnar Gundersen,1,* Richard Potvin2,*1Privatsykehuset Haugesund, Haugesund, Norway; 2Science in Vision, Burleson, TX, USA *These authors contributed equally to this workBackground: To compare near, intermediate, and distance vision, and quality of vision using appropriate subjective questionnaires, when monofocal or apodized diffractive multifocal intraocular lenses (IOLs are binocularly implanted.Methods: Patients with different binocular IOLs implanted were recruited after surgery and had their visual acuity tested, and quality of vision evaluated, at a single diagnostic visit between 3 and 8 months after second-eye surgery. Lenses tested included an aspheric monofocal and two apodized diffractive multifocal IOLs with slightly different design parameters. A total of 94 patients were evaluated.Results: Subjects with the ReSTOR® +2.5 D IOL had better near and intermediate vision than those subjects with a monofocal IOL. Intermediate vision was similar to, and near vision slightly lower than, that of subjects with a ReSTOR® +3.0 D IOL implanted. The preferred reading distance was slightly farther out for the +2.5 D relative to the +3.0 D lens, and farthest for the monofocal. Visual acuity at the preferred reading distance was equal with the two multifocal IOLs and significantly worse with the monofocal IOL. Quality of vision measures were highest with the monofocal IOL and similar between the two multifocal IOLs.Conclusion: The data indicate that the ReSTOR +2.5 D IOL provided good intermediate and functional near vision for patients who did not want to accept a higher potential for visual disturbances associated with the ReSTOR +3.0 D IOL, but wanted more near vision than a monofocal IOL generally provides. Quality of vision was not significantly different between the multifocal IOLs, but patient self-selection for each lens type may have been a factor.Keywords: multifocal IOL, near vision, cataract, presbyopia

  16. Experiment design for through-focus testing of intraocular lenses

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

    2013-11-01

    Eye models to test intraocular lenses (IOLs) in an optical bench are commonly designed in agreement with the ISO 11979-2 and 11979-9 standard requirements. However, modifications to the ISO eye model have been proposed to test IOLs in conditions closer to real human eye. Wavefront analysis and aberration characterization, wavelength dependence, efficiency, off-axis performance and imaging degradation under certain amount of misalignment can thus be measured in vitro. The main parts of the system to test IOLs are: the illumination system and object test, the eye model including the IOL immersed in a wet cell and a microscope assembled to a sensor that magnifies and captures the aerial image of the object formed by the eye model. A problem concerning the simultaneous variation of defocus and magnification arises when using the microscope to capture out-of-focus images in a through-focus study. Using the eye model, we study the problem of implementing a through-focus measurement of the imaging quality of an IOL. We find a solution based on geometrical optics and compare it with other proposals reported in the literature. The effects on the measurement of the Modulation Transfer Function and the Point Spread Function are predicted. Experimental results are obtained and discussed.

  17. Surgical management of astigmatism with toric intraocular lenses

    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.

  18. Quality of vision through diffractive bifocal intraocular lenses.

    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...

  19. Phacoemulsification and acryl foldable intraocular lens implantation in dogs: 32 cases

    Yi, Na-Young; Park, Shin-Ae; JEONG, Man-Bok; Kim, Won-Tae; Kim, Se-Eun; Chae, Je-Min; Seo, Kang-moon

    2006-01-01

    This study evaluated the surgical outcome and complications of phacoemulsification and the implantation of an acryl foldable intraocular lens (IOL) with a squared edge in dogs with cataracts. Thirty-two eyes from 26 dogs were examined. The mean follow up period was 75.9 days ranging from 23 to 226 days. The complications after phacoemulsification were posterior capsular opacity (PCO) around the IOL (n = 11), ocular hypertension (n = 4), focal posterior synechia (n = 4), hyphema (n = 3) and co...

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

    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

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

    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.

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

    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.

  3. Rotational stability of the AcrySof SA60TT toric intraocular lenses: A cohort study

    Gale Richard

    2008-05-01

    Full Text Available Abstract Background To evaluate the rotational stability of the three types of AcrySof SA60TT toric intraocular lenses (Alcon, Switzerland in cataract surgery after the first postoperative week. Methods A retrospective study of 44 eyes in 33 patients. All patients underwent similar uncomplicated phacoemulsification cataract surgery. Seven eyes with corneal astigmatism of less than 1.5 D were implanted with the AcrySof SA60T3 intraocular lens. Seventeen eyes with astigmatism between 1.5 D and 2.25 D received the SA60T4 intraocular lens, and 20 eyes with more than 2.25 D of corneal astigmatism received the SA60T5 intraocular lens. Intraoperatively, the axis of the toric lens was aligned to the steepest axis of the corneal astigmatism. Main outcome measure was the postoperative position of the lens, assessed at 1 week and 3 months, using a specially designed angle measuring eyepiece for the slit lamp. Results There was no significant difference in the rotational stability of the three types of toric intraocular lenses. Overall, the postoperative rotation was within 5 degrees in 95% and within 2 degrees in 68% of eyes. The mean absolute rotation was 2.2 ± 2.2 degrees. No lens showed more than 9 degrees of rotation, and no lens required secondary repositioning. There was no trend for either clockwise or anti-clockwise rotation. The surgical procedure did not change the corneal astigmatism. Conclusion Once placed to it's position, each of the three types of the AcrySof SA60TT toric intraocular lenses demonstrate rotational stability in the capsular bag.

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

    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...

  5. Astigmatism correction in cataract surgery with Rayner toric intraocular lenses

    Painter, Sally

    2010-01-01

    Sally L Painter, Kikkeri S Arun, Jonathan K Kam, CK PatelOxford Eye Hospital, John Radcliffe Hospital, Headley Way, Headington, Oxford, United KingdomBackground: Cataract surgery is increasingly regarded as a refractive procedure. Corneal astigmatism can be reduced by the insertion of a toric intraocular lens (T-IOL). Rayner T-flex T-IOLs are licensed for the correction of astigmatism.Methods: In this retrospective study, 46 eyes from 34 patients, in whom T-IOLs were inserted, have been exami...

  6. [Refraction after Implantation of Multifocal and Presbyopia-Correcting Intraocular Lenses].

    Kretz, F T A; Linz, K; Mueller, M; Gerl, M; Koss, M J; Gerl, R H; Auffarth, G U

    2015-08-01

    Nowadays, further developments in the field of intraocular lenses offer a higher level of spectacle independence for our patients. As light gets scattered on different focal points a wider range of defocus is created. This greater defocus area makes it more difficult for us to determine the objective or subjective refraction. This contribution is concerned with the difficulties of measuring visual acuity in different intraocular lens designs and different measurement distances. Measuring refraction after implantation of a multifocal intraocular lens is a complex procedure and the experience of the examiner plays a crucial role. Retinoscopy, keratometry and the defocus curve are reliable methods for testing, while the auto refractometer, bichromatic testing and the cross-cylinder have limitations. PMID:25927177

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

    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...

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

    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...

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

    Unsal, Ugur; Baser, Gonen

    2016-01-01

    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). PMID:27340560

  10. Refractive errors induced by displacement of intraocular lenses within the pseudophakic eye.

    Atchison, D A

    1989-03-01

    Simple methods were developed to estimate refractive errors when intraocular lenses are not fitted optimally within pseudophakic eyes. The accuracy of these methods was determined by comparing results obtained with them to results obtained by raytracing through a model eye. Accuracy was good for longitudinal displacement and tilting, and reasonable for transverse displacement. Refractive errors are related linearly to the magnitude of the longitudinal displacement, and are related to the square of the magnitude of tilt or transverse displacement. The refractive error upon transverse displacement is quadratically dependent upon lens shape. PMID:2717142

  11. Postoperative Astigmatic Outcomes Based on the Haptic Axis of Intraocular Lenses Inserted in Cataract Surgery

    Kim, In-Tae; Park, Hae-Young Lopilly; Kim, Hyun-Seung

    2011-01-01

    Purpose This study was conducted to compare post-operative astigmatic outcomes of two groups, with-the-rule (WTR) and against-the-rule (ATR) astigmatism patients, according to the haptic axis of intraocular lenses (IOLs) inserted in cataract surgery. Methods Seventy-two eyes with WTR astigmatism and 79 eyes with ATR astigmatism had cataract surgery through a clear corneal temporal incision. These two groups of eyes were then each divided into 2 groups based on whether the haptic axis of the i...

  12. Prospective evaluation of visual outcomes with three presbyopia-correcting intraocular lenses following cataract surgery

    Ang RE; Martinez GA; EM Cruz; Tiongson AA; Dela Cruz AG

    2013-01-01

    RE Ang,1,2 GA Martinez,2,3 EM Cruz,1 AA Tiongson,1 AG Dela Cruz1 1Asian Eye Institute, Makati City, Philippines; 2Cardinal Santos Medical Center, San Juan City, Philippines; 3Pasig City General Hospital, Pasig City, Philippines Purpose: To compare the visual acuity and quality of vision achieved with three widely-used intraocular lenses (IOLs) in subjects with bilateral cataracts. Patients and methods: This three-arm, parallel, prospective, partially masked, single-surgeon study randomized 78...

  13. Ultraviolet or blue-filtering intraocular lenses: what is the evidence?

    Downes, S M

    2016-02-01

    Cataract surgery was revolutionised by the introduction of modern intraocular lenses in the late 1940's. By the late 1960's to 1970's evidence had emerged that short-wavelength light caused phototoxicity at the retina and retinal pigment epithelium. By the early 1980's ultraviolet filters had been incorporated into intraocular lenses. This caused intense controversy, as there was concern that the UV-filtering chromophore might leach out into the eye causing toxicity. With the arrival of blue-filtering intraocular lenses (BFIOLs) in 1990's, a further debate was ignited as to their safety and potential disadvantages. Selecting the optimal performing intraocular lens to obtain the best visual performance with the fewest potential drawbacks has become complex and challenging for cataract surgeons and their patients with the wide choice of lenses available. Choosing a personalised lens to address astigmatism, presbyopia, spherical aberration, chromatic aberration, and potentially to shield the retina from short-wavelength light is now possible. The potential benefits and possible side effects of these different innovations emphasise the importance of assessing the evidence for their clinical utility, allowing the surgeon and the patient to weigh-up the risk benefit ratio and make an informed decision. The BFIOLs were developed to reduce cyanopsia, address chromatic aberration, and improve contrast sensitivity in different lighting conditions, as well as to prevent short-wavelength light reaching the retina thus potentially reducing the risk of developing age-related macular degeneration. Further design development of the BFIOLs was to mimic the natural crystalline lens absorption and transmittance properties in adulthood. Multiple publications have reported on the potential benefits and pitfalls of implanting a blue-filtering lens. The potential disadvantages raised in the literature over the last 25 years since their introduction, regarding compromise of visual

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

    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...

  15. Intraocular lens exchange through a 3.2-mm corneal incision for opacified intraocular lenses

    Kubaloglu Anil

    2011-01-01

    Full Text Available Aim: The aim was to evaluate visual and refractive results and complications of intraocular lens (IOL exchange through a 3.2 mm corneal incision for opacified IOLs. Materials and Methods: This retrospective study comprised 33 eyes of 32 patients with IOL opacification requiring an IOL exchange between July 2003 and March 2007. Exchange surgery was performed through a 3.2-mm temporal clear corneal incision followed by implantation of a new foldable hydrophobic IOL. Uncorrected visual acuity (UCVA, best spectacle-corrected visual acuity (BSCVA, topographical astigmatism, and refractive cylinder were evaluated. Surgically induced astigmatism (SIA was calculated and complications were recorded. Results: Opacification was observed in 25 eyes (76% with Aqua-Sense, 3 eyes (9% with Hydroview, 3 eyes (9% with MemoryLens IOLs, and 2 eyes (6% with DgR. The mean follow-up period was 36.54 months. An uneventful IOL exchange was achieved in 18 eyes (55%. Zonular dehiscence occurred in 9 eyes (27%, and posterior capsule tear developed in 4 eyes (12%. The mean preoperative BSCVA (mean ± standard deviation, decimal scale was 0.13 ± 0.08 (mean: 20/150, range 20/2000 to 20/60 and improved to 0.63 ± 0.18 (mean: 20/32, range 20/60 to 20/20, P < 0.001. The mean SIA was 0.70 D. Seven eyes (21% had 0.5 D or lower SIA. Conclusion: IOL exchange is a technically challenging procedure with potential risks of reversing the advantages of a prior small-incision cataract surgery. The use of a small corneal incision for IOL exchange could preserve the advantages of modern phacoemulsification surgery with acceptable SIA related to the procedure.

  16. Causes of elevated intraocular pressure following implantation of phakic intraocular lenses for myopia.

    Almalki, Salem; Abubaker, Abdullah; Alsabaani, Nasser A; Edward, Deepak P

    2016-04-01

    The purpose of this study is to present the causes and visual acuity outcomes in patients with elevated intraocular pressure (IOP) following implantable collamer lens (ICL) implantation. A chart review identified patients who developed high IOP at any postoperative examination and a minimum follow-up period of 3 months after ICL implantation. Data are reported out to 6 months postoperatively. Outcome measures included causes of elevated IOP, best-corrected visual acuity (BCVA) at last visit, number of glaucoma medications, other interventions, and glaucomatous damage. Elevated IOP occurred in 58 (10.8 %) of 534 eyes that received ICL. The mean age was 28 ± 7.2 years. The preoperative IOP was 16.3 ± 1.2 mmHg. Elevated IOP most commonly occurred on the first postoperative day (23/58 (39.7 %) eyes) due to retained viscoelastic. This was followed by steroid response in 22/58 (37.9 %) eyes at 2-4 weeks postoperatively. IOP elevation in 6 (10.3 %) eyes was related to high ICL vault and pupillary block, and in 4 (6.9 %) eyes due to synechial angle closure. At last visit, BCVA was 20/40 or better in 56/58 (96.6 %) eyes, and 5/58 (8.6 %) eyes remained on glaucoma medications due to persistent steroid response (2 eyes), synechial angle closure glaucoma (1 eye), and other causes (2 eyes). One eye showed glaucomatous damage. Two eyes with high vault and elevated IOP underwent ICL explantation. There is a moderate risk of transiently developing elevated IOP after ICL implantation. Thorough removal of viscoelastic and use of anti-glaucoma medications during steroid use will reduce the majority of cases with postoperative IOP elevation. PMID:26265323

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

    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.

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

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

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

    R. K. Khandal

    2009-01-01

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

  20. Clinical features of removing phakic intraocular lenses in cataract at high myopia

    M. E. Konovalov

    2014-07-01

    Full Text Available Purpose: Development and an assessment of efficiency of a technique of phakic intraocular lenses (FIOL at cataract phacoemul- sification.Methods: 25 FIOL, a pupillary lens RSC-3, a posterior chamber lens, production of MNtK, Russia, and posterior chamber lens ICL S4 StAAR were removed. Before complex surgical intervention (FIOL + phacoemulsification were carried out standard ophthalmo- logic examination, and also automatic detection of density of endothelial cells.Results: the developed technique of removal of FIOL included subconjunctival anesthesia, formation of a corneal tunnel, filling of the anterior chamber viscoelastic, FIOL mobilization, removal of the bottom haptic element in the anterior chamber, removal of the top haptic element in the of anterior chamber, FIOL removal. In the early postoperative period in 8% transitory hypertensia was observed, in one case (4% cornea hypostasis developed. In 92.4% of cases of the maximal visual acuity with correction was corresponded to the planned. Loss of endothelial cells after operation made 4.8% that in full corresponds to standard loss of cells after not complicated phacoemulsification.Conclusion: the technique of removal of FIOL developed as part of this research allows enough effectively and to carry out safelyto patients surgical treatment of the complicated cataract with a phakic intraocular lenses explantation.

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

    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

  2. Irradiation system for two-photon induced activation of agents in novel intraocular lenses

    Klämpfl, Florian; Roth, Stephan; Schmidt, Michael

    This paper presents a newly designed irradiation system for the photochemically triggered two-photon activation of an agent loaded in novel intraocular lenses. After activation, this agent suppresses the formation of after-cataract, a very common disease after the treatment of an eye cataract by implanting an intraocular lens. For this application, intrinsic safety is also important: the laser radiation is applied to one of the most light-sensitive organs: the eye. This has to be taken into account during development of the system. Moreover, the activation uses a two-photon process so a relatively small laser focus is required. To address these issues in combination with economic requirements, a mirror based objective was designed and built, specifically tailored to these needs. Besides the laser beam guidance elements, the irradiation system consists of a camera based monitoring module and an illumination unit. While the first part of the paper shows the design of the system, the second part presents the results of the characterization of the system. The paper closes with a conclusion and an outlook discussing what further development is needed to prepare the system for treatments of human eyes.

  3. [Optimisation of the visualisation technique for optical paths through intraocular lenses for characterisation of multifocal imaging properties of Fresnel-zone plates].

    Reiß, S; Forbrig, J; Guthoff, R F; Terwee, T; Stolz, H; Siewert, S; El-Tamer, A; Hinze, U; Chichkov, B N; Stachs, O

    2014-12-01

    The utilisation of the diffractive properties of Fresnel zone plates offers the possibility of intraocular lens designs with multiple foci. Such intraocular lenses can be manufactured by two-photon polymerisation (2PP). This paper explains the underlying concept and shows the principles for visualisation of the focus properties of such implants. PMID:25519505

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

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

    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

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

    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...

  7. 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

    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.

  8. Prospective evaluation of visual outcomes with three presbyopia-correcting intraocular lenses following cataract surgery

    Ang RE

    2013-09-01

    Full Text Available RE Ang,1,2 GA Martinez,2,3 EM Cruz,1 AA Tiongson,1 AG Dela Cruz1 1Asian Eye Institute, Makati City, Philippines; 2Cardinal Santos Medical Center, San Juan City, Philippines; 3Pasig City General Hospital, Pasig City, Philippines Purpose: To compare the visual acuity and quality of vision achieved with three widely-used intraocular lenses (IOLs in subjects with bilateral cataracts. Patients and methods: This three-arm, parallel, prospective, partially masked, single-surgeon study randomized 78 subjects to receive bilateral Crystalens® Advanced Optics (AO accommodating IOLs, AcrySof® IQ ReSTOR® +3.0 multifocal IOLs, or TECNIS® Multifocal IOLs. Examinations were assessed through days 120 to 180. Results: The Crystalens AO group had statistically significantly better monocular and binocular, high-contrast (HC and low-contrast (LC uncorrected intermediate visual acuity, HC and LC distance-corrected intermediate visual acuity, and significantly fewer monocular and binocular halos and starbursts than did the ReSTOR and TECNIS groups. Monocular and binocular, HC and LC uncorrected near visual acuity exhibited no significant differences among the three lenses. For monocular and binocular HC distance-corrected near visual acuity, the Crystalens AO performed significantly better than the TECNIS and was not significantly different from the ReSTOR. For monocular and binocular LC distance-corrected near visual acuity, the Crystalens AO performed significantly better than both the ReSTOR and the TECNIS. Contrast sensitivity was clinically similar between groups. The Crystalens AO produced statistically fewer halos and starbursts. Conclusion: All three IOLs had excellent uncorrected acuity results at all distances and had good safety, confirming the established safety and effectiveness of these IOLs. Distance and near vision were similar between all three IOLs, and the Crystalens AO provided statistically significantly better intermediate vision. Keywords

  9. Interaction with therapeutic soft contact lenses affects the intraocular efficacy of tropicamide and latanoprost in dogs.

    Hatzav, M; Bdolah-Abram, T; Ofri, R

    2016-04-01

    Therapeutic soft contact lenses (TSCLs) are frequently used to support or protect the cornea during healing. Our aim was to quantitatively evaluate the efficacy of topical medications in TSCL-fitted dogs and determine whether it is affected by the presence of TSCLs. In Phase I, pupil diameter was measured in eyes treated with tropicamide and in eyes covered with TSCLs and then treated with tropicamide, with 1-week intervals between sessions. In Phase II, intraocular pressure (IOP) was measured in uncovered and TSCL-covered eyes treated with latanoprost, with 1-week intervals between sessions. Tropicamide caused significant mydriasis in both uncovered and TSCL-covered eyes (P = 0.005). On the other hand, latanoprost caused a significant decrease in IOP when applied to uncovered eyes (P = 0.002), but had no significant effect on IOP when applied to TSCL-covered eyes (P = 0.7). As we used the same dogs and identical TSCLs throughout the study, we conclude that the different outcomes of the two drugs are due to properties of the drugs themselves, or their formulations, affecting their interaction with the TSCLs. The clinical efficacy of topical drugs applied to TSCL-covered eyes may have to be determined for each drug and/or formulation. PMID:26411631

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

    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

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

    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.

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

    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

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

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

    2016-01-01

    Phacoemulsification with in-the-bag intraocular lens (IOL) implantation is the standard procedure for cataract surgery. Pigment dispersion and uveitis can result when an IOL is placed in the sulcus. We report a case of a 64-year-old woman, with pigmentary glaucoma, who developed recurrent uveitis following uneventful cataract surgery and an in-the-bag hydrophobic acrylic IOL implant. Recurrent uveitis did not subside despite use of topical steroids over 3 months. Dilated examination revealed capsulophimosis with anterior dislocation of the IOL haptic. The mechanical trauma to the iris due to the displaced haptic was implicated as the cause of recurrent uveitis, which completely resolved after capsular excision and IOL repositioning. This case illustrates a rare cause of recurrent uveitis due to IOL haptic dislocation following severe capsulophimosis. PMID:26921366

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

    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.

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

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

    2014-03-01

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

  16. Personal A-constant in relation to axial length with various intraocular lenses

    Mohamed A Eldaly

    2014-01-01

    Full Text Available Purpose: To study the relationship between the axial length and personal A-constant for the 1-piece Tecnis (Abbott ZCB00, AcrySof MA60AC (Alcon and the Quatrix aspheric preloaded (CROMA intraocular lenses (IOL. Materials and Methods: Patients matching the inclusion criteria were further subdivided according to the implanted IOL in this prospective comparative study. The obtained refractive outcomes were introduced into the formula installed in the biometry machine (Humphrey model 820 ultrasonic biometer to obtain the personal A-constant for each eye. Polynomial regression analysis was done to study the individualized A-constant for each type of IOL in relation to preoperative axial length measurement. Results: Two hundred and forty five eyes of 186 patients were enrolled into this study, of whom 73 eyes with Tecnis 1-piece, 116 eyes with MA60AC, and 56 eyes with Quatrix. The median of personalized A-constant for Tecnis 1-piece, MA60AC, and Quatrix were 119.21 (SD 1.3, Std. Mean error 0.15, 119 (SD 1.2, Std. Mean error 0.11 and 120.4 (SD 1.2, Std. Mean error 0.16 respectively. Regression plots for the same range of axial length among all the groups showed that the Tecnis1 group followed the same pattern of the Quatrix group in which there was a linear relationship of a trend towards myopia when the axial length had increased and a hyperopic shift when decreased. This relationship changed into a plateau when the axial length became in the range of 23.5 mm to 27 mm in the MA60AC group. Conclusions: Personal A-constant follows different trends with different IOLs even for the same range of axial length.

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

    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

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

    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 ...

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

    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

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

    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

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

    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

  2. Comparative Assessment of Implantation of Bifocal Diffractiverefractive and Monofocal Intraocular Lenses

    Kh.P. Takhchidi

    2009-03-01

    Full Text Available ABSTRACT Purpose To assess the functional results of implantation of bifocal diffractiverefractive and monofocal lenses. Material and methods Long-term visual functions in patients with bifocal diffractive-refractive lenses (MIOL-Accord, AcrySof Restor ® and monofocal lens (MIOL-2 were examined. Postop refraction, distance and near visual acuity, visual acuity at low-contrast values and contrast sensitivity were evaluated. Results Distance visual acuity in patients with MIOL-Accord and AcrySof Restor® did not differ from the visual acuity in patients with MIOL-2. Uncorrected and corrected near visual acuity was better in eyes with diffractive lenses. Visual acuity at low-contrast values and with glare, contrast sensitivity in patients with diffractive lenses were comparable (p>0,05, but were slight lower than those with the monofocal lens. Conclusion Despite different design the bifocal diffractive-refractive lenses MIOLAccord and AcrySof Restor® provided comparable postop visual functions. Uncorrected near visual acuity in patients with the multifocal lens was better than in monofocal patients. Uncorrected distance vision show comparable results in multifocal and monofocal patients. Visual acuity at low-contrast values and contrast sensitivity with glare in patients with diffractive lenses were slight lower than with the monofocal lens.

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

    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.

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

    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...

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

    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 ...

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

    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...

  7. Experience with extracapsular extraction and binkhorst 2-loop intraocular lenses: preliminary communication.

    Marsh, R J; Andrew, N C

    1981-01-01

    Extracapsular cataract extraction and implantation of a Binkhorst 2-loop intraocular lens were performed on 50 patients. The majority of the patients achieved a corrected postoperative acuity of 6/9. Operative, immediate postoperative and late postoperative complications are discussed. The commonest postoperative complication was the formation of a dense capsular membrane which required capsulotomy in 9 patients. Suggestions are put forward for improving the result of this rewarding operation.

  8. Intraocular lens employed for cataract surgery

    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.

  9. Intraocular lens employed for cataract surgery

    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.

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

    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.

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

    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.

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

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

    2016-01-01

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

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

    Jeroni Nadal

    2015-01-01

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

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

    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

  15. Comparison Between Digital and Manual Marking for Toric Intraocular Lenses: A Randomized Trial.

    Elhofi, Abdel Hamid; Helaly, Hany Ahmed

    2015-09-01

    To compare the clinical outcome of digital and manual marking for toric intraocular lens (IOL) alignment. This is a prospective clinical study that included 60 eyes of 60 patients undergoing cataract surgery with coexisting corneal astigmatism more than 1 diopter (D). The eyes were randomly assigned to either digital image guidance using VERION digital marker (Alcon Laboratories, Ft. Worth, TX) or manual slitlamp-assisted preoperative marking using pendulum-attached marker. Tecnis toric IOL (Abbott Medical Optics, Inc, Santa Ana, CA) was implanted in all cases. The mean postoperative uncorrected distance visual acuity (UCDVA) for the digital-marking group was 0.12 + 0.12 logMAR, and for the manual-marking group was 0.18 + 0.14 logMAR (P = 0.104). The mean deviation from targeted induced astigmatism (TIA) for the first group was 0.10 + 0.08 D and for the second group was 0.20 + 0.14 D (P = 0.001). The mean postoperative toric IOL misalignment measured by the slitlamp was 2.4° + 1.96° for the first group and was 4.33° + 2.72° for the second group (P = 0.003). Accurate alignment of the toric IOL is important to achieve the desired astigmatism correction. VERION system has the advantage of preoperative planning and intraoperative digital guidance of the toric IOL alignment. The use of VERION system resulted in less postoperative deviation from TIA and showed less postoperative toric IOL misalignment than using manual-marking technique. PMID:26402830

  16. Materials for intraocular lenses enabling photo-controlled tuning of focal length in vivo

    Träger, Jens; Heinzer, Jasmin; Kim, Hee-Cheol; Hampp, Norbert

    2007-07-01

    Typical postoperative complications in cataract surgery are that refractive power and curvature of the implanted intraocular lens (IOL) do not have optimum values, requiring the patient to wear viewing aids. This is mainly because biometric data relevant for calculation of the IOL's shape cannot be determined with the required precision. Hence, there is a need for methods to tune the focal length postoperatively in a non-invasive manner. We have developed polymers where we can induce a change in refractive index by linking or cleaving bonds between a su.ciently large number of side groups of the polymer main chain in a photoinduced cycloaddition or cycloreversion reaction, respectively. These photoreactions lead to a change in refractive index great enough to be interesting for the concept of in vivo tunable IOL's. The photochemical reaction can be triggered by a two-photon process (TPA) using a pulsed laser system, i.e. the energy required for bond breaking is provided by two photons in the visible range. This is important because light in the UV cannot induce undesired changes of the refractive index owing to the strong UV-absorption of the cornea. Undesired changes due to light in the visible range of the spectrum are unlikely to happen because photon density of sun light is much too low for TPA. Due to the excellent spatial resolution that can be achieved with two-photon processes one cannot only modify the refractive index of the entire lens but also selectively in well defined areas enabling to correct for aberrations such as astigmatism. Here, we present new polymers that do not only exhibit a photo induced change of refractive index great enough to induce a change of focal length of more than two diopters in a standard IOL. These new polymers have also significantly improved material properties with respect to the fabrication of the IOL and the TPA-sensitivities and the light energy required to induce the refractive index change.

  17. Optimum form of posterior chamber intraocular lenses to minimize aberrational astigmatism.

    Takei, K; Hommura, S; Okajima, H

    1995-01-01

    To optically determine the optimum form for a posterior chamber intraocular lens (PC IOL), we calculated the aberrational astigmatism induced by tilt and decentration of the PCIOL using an exact raytracing. First, the position and the radii of curvatures of the IOL were determined to make an emmetropic eye model using a paraxial raytracing. Next, the chief rays originating from the fovea centralis were traced backward through the tilted and/or decentrated PC IOL, the center of the pupil and the cornea, using trigonometric raytracing. Finally, the maximum and minimum aberrational astigmatism were calculated based on the Coddington's Equations for the sagittal and the tangential foci of the ray. All the refractive parameters in Gullstrand's No. 1 schematic eye were adopted. The effect of varying anterior corneal asphericity on the results was also examined. Four forms of polymethylmethacrylate PC IOLs (refractive index: 1.491) were analyzed; a plano-convex IOL with the curved surface facing the cornea, and three bi-convex forms with the ratio of anterior-to-posterior radii of curvatures of 1:4, 1:2 and 1:1, respectively. The 1:4 bi-convex form showed the lowest values for the maximum aberrational astigmatism calculated at every combination of tilt and decentration except 0 degrees tilt and/or 0 mm decentration. The aberrational astigmatism with the 1:4 bi-convex form of PC IOL did not exceed 1.0 D at the maximum tilt and decentration. The variation of anterior corneal asphericity did not influence the results. We conclude that the 1:4 bi-convex form of PC IOL minimizes the postoperative astigmatism induced by tilt and/or decentration of the lens. PMID:8926647

  18. Clinical outcomes using standard phacoemulsification and femtosecond laser-assisted surgery with toric intraocular lenses

    Espaillat, Arnaldo; Pérez, Obniel; Potvin, Richard

    2016-01-01

    Purpose To compare the 1-month and 1-year results of toric intraocular lens (IOL) implantation with standard (manual) phacoemulsification vs femtosecond laser-assisted surgery. Patients and methods Refractive data, visual acuity data, and ocular aberration measured with a wavefront aberrometer were collected for two groups of patients from one site. The first group had standard phacoemulsification, while the second group had femtosecond laser-assisted surgery, and both groups were implanted with toric IOLs, either monofocal or multifocal. Differences in visual acuity, refractive outcomes, and higher order aberrations – total, corneal, and internal – were evaluated at 1 month and 1 year postoperatively. Results Toric IOLs were implanted in 62 eyes using standard phacoemulsification and 53 eyes using femtosecond laser-assisted surgery. Uncorrected visual acuity and best-spectacle-corrected visual acuity at 1 month and 1 year were not statistically significantly different between the groups (P>0.05) nor was the mean cylinder or mean spherical equivalent refraction (P>0.12). Total ocular higher order aberrations were significantly different between the groups (P<0.05), but absolute differences appeared to be the same. Internal vertical coma was significantly lower in the femto group at 1 year (P=0.03). Differences in aberrations did not correlate with corrected or uncorrected visual acuity. Conclusion Patients who underwent uncomplicated lens surgery with toric IOLs in both the groups had comparable refractive outcomes in terms of visual acuity and residual refraction at 1 year. The femto group had significantly lower internal vertical coma at 1 year. PMID:27099462

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

    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.

  20. Experimental study of aberration characteristics changing in case of intraocular lenses decentration

    D.G. Zhaboiedov

    2014-01-01

    Full Text Available Nowadays the creation of high functional vision in intraocular correction which depends much on the optical properties of implanted IOL is of great importance. So far as even after an impeccably performed operation an IOL decentration occurs that inevitably induces aberrations which reduce the vision of a pseudophakic eye, it is important to use IOL models that are least sensitive to decentration. Purpose. To identify IOL models that are less sensitive to decentration using an artificial model of eye optical system. Material and methods. The experimental study of aberration properties of different IOL models TECNIS®, SA60AT, SN60WF, SL-907 «CentriX DZ» has been conducted on an original model. Results. At first the aberrometry of the eye model was performed without IOL, later an investigated IOL was placed into the eye model and centered by localization of mirror images of LEDs centering. Artificially created IOL decentration along the X-axis had ±0.5mm and ±1.0mm values, IOL angular rotations around the vertical axis were ±4° and ±8°. Decentration of all IOL models as well as its rotation around the vertical axis caused the change in the aberrations amplitude. The study showed that the SL-907 «CentriX DZ» IOL model is less sensitive to any IOL decentration and rotation (tilt, the TECNIS® and SN60WF models are more sensitive. The SA60AT IOL is the most sensitive to the decentr ation and rotation. Conclusions. Thus, the IOL decentration in the range of ±1mm and rotation angles of ±8 degrees cause an increase in the amplitude of the aberration modes, equal values of IOL decentration entail unequal changes in the values of aberrations between different IOL models. It has been found that the SL-907 «CentriX DZ» IOL model is less sensitive to decentration, rotation and tilt, that allows its use in cases with a high risk of its displacement in the postoperative period.

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

    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

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

    Giuliano de Oliveira Freitas

    2014-01-01

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

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

    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.

  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

    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

  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

    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. Retinal image quality with the different types of intraocular lenses including new idea of the hybrid IOLs

    Siedlecki, D.; Zając, M.; Nowak, J.

    2007-07-01

    Cataract is one of the most frequent reasons of blindness all around the world. Its treatment relies on removing the pathologically altered crystalline lens and replacing it with an artificial intraocular lens (IOL). There exists plenty of types of such implants, which differ in the optical materials and designs (shapes). However one of the important features, which is rather overlooked in the development of the intraocular implants is the chromatic aberration and its influence on the retinal image quality. In this study authors try to estimate the influence of the design and optical material of the implant on the retinal image quality in the polychromatic light, taking into consideration several exemplary types of IOLs which are commercially available. Authors also propose the partially achromatized hybrid IOLs, the longitudinal chromatic aberration (LCA)of which reduces the total LCA of the phakic eye to the level of a healthy eye's LCA. Several image characteristics, as the polychromatic Point Spread Function (PSF) and the Modulation Transfer Function (MTF) and the polychromatic encircled energy are estimated. The results of the simulations show the significance of the partial chromatic aberration correction.

  7. Safety and effectiveness of a single-piece hydrophobic acrylic intraocular lens (enVista® – results of a European and Asian-Pacific study

    Heiner P

    2014-03-01

    Full Text Available Peter Heiner,1 Edoardo Ligabue,2 Alex Fan,3 Dennis Lam31Vision Eye Institute, Southport, QLD, Australia; 2Ophthalmic Center, San Siro Clinic, Milan, Italy; 3Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong KongPurpose: To evaluate the safety and effectiveness of a single-piece hydrophobic acrylic intraocular lens (IOL (enVista® MX60; Bausch and Lomb Incorporated, Rochester, NY, USA following implantation to correct aphakia subsequent to extracapsular cataract extraction in adults.Subjects and methods: This was an open-label, non-interventional, observational study conducted in 19 university and private-practice settings in Europe and the Asia-Pacific region to investigate clinical outcomes of the MX60 IOL in standard practice. Eligible subjects were at least 18 years of age and had undergone standard phacoemulsification and extracapsular cataract extraction with implantation of the MX60 IOL. The primary safety endpoint was the occurrence of adverse events, and the primary effectiveness endpoints included visual and refractive outcomes and stability, with data collected up to 2 years post-procedure.Results: In this multicenter study, pooled data of 255 eyes were collected and analyzed. Excellent visual and refractive outcomes and stability were demonstrated. At postoperative visit 4 (61–180 days postoperative, 62.2% of subjects achieved a Snellen best-corrected distance visual acuity (CDVA of 20/20 (decimal 1.00, and 97.8% of subjects achieved a CDVA of 20/40 (decimal 0.50 or better. One eye (1.0% underwent neodymium:yttrium aluminum garnet capsulotomy at 12 months post-procedure. No glistenings of any grade were reported for any subject at any visit. Adverse events were infrequent and were consistent with incidences generally reported with cataract surgery.Conclusion: This study, which enrolled all comers, provided evidence of the excellent safety and effectiveness of the MX60

  8. Polymers for refractive index change in intraocular lenses: a novel approach for photoinduced tuning of focal length

    Träger, Jens; Kim, Hee-Cheol; Hampp, Norbert

    2006-02-01

    Before an intraocular lens (IOL) is implanted during cataract surgery, biometric data of the patient's eye have to be determined to calculate the thickness and shape of the IOL. In particular the postoperative anterior chamber depth is an important parameter to predict the correct shape of the IOL. This value, however, cannot be measured without significant uncertainities. We present a solution to this problem, describe novel polymers suitable for IOLs which refractive indices can be changed non-invasively in a photo-induced process. The focal length can be modified by about 2 D, which is sufficient to achive ideal acuteness of vision for almost all patients with implanted IOLs. The change in refractive index is accomplished by linking or cleaving bonds between a sufficiently large number of side groups of the polymer main chain in a photoinduced cyloaddition or cycloreversion, respectively. The photochemical reaction can also be triggered by a two-photon process (TPA) using a pulsed laser system, i.e. the energy required for bond breaking is provided by two photons in the visible range. Light in the UV as well as the visible range of the spectrum cannot induce undesired changes of the refractive index owing to the strong UV-absorption of the cornea and photon densities much too low for TPA, respectively. Due to the excellent spatial resolution that can be achieved with two-photon processes not only modification of the refractive index of the entire lens but also selectively in well defined areas is possible enabling the correction for aberrations such as astigmatism.

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

    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

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

    Wilson Takashi Hida

    2008-06-01

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

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

    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...

  13. Evaluation of a class of polyurethane materials for intraocular lens manufacturing.

    Bozukova, Dimitriya; Bertrand, Virginie; Pagnoulle, Christophe; De Pauw-Gillet, Marie-Claire

    2015-08-01

    Ophthalmic lenses are medical devices with considerable requirements in terms of optical, biomechanical and biological performance. There is limited number of materials used for their manufacturing, comprising mainly silicones and poly(meth)acrylates. This series of publications aims at investigating the applicability of thermoplastic polyurethane elastomers (TPU) for the manufacturing of ophthalmic lenses and examining the properties of the respective devices. This study is related to the synthesis of TPUs with chemical compositions that comprise chemically grafted filters for the hazardous-light. GC-MS, attenuated total reflectance Fourier transform infrared spectroscopy, and UV-vis spectroscopies confirmed the reaction completion and the beneficial effect of the filters on the light transmittance, respectively. Relatively high refractive index of the material was measured and allows for the manufacturing of thinner lenses. The contrast sensitivity determined for a model intraocular lens (IOL) was satisfactory. Few optical defects were, however, present on the model lens prepared by thermoplastic injection molding. The elasticity of the materials was evaluated in view to their potential applicability as foldable IOLs by determining their glass transition temperature and their Young modulus and measuring their shore A. The TPU materials demonstrated more bioadhesive character compared with a benchmark hydrophilic acrylic reference material, which is already used for IOL manufacturing. PMID:25352276

  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

    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

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

    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

  17. 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

    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),

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

    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

  19. Significance of intraocular lens power calculation.

    M. Singh; Dahalan, A

    1987-01-01

    A total of 94 patients underwent extracapsular cataract extraction and insertion of Sinsky style two-loop posterior chamber intraocular lenses. Forty-six eyes received a standard power IOL and 48 eyes were given a preoperatively calculated IOL. A significant difference was found in the two groups with regard to the postoperative refractive error and uncorrected visual acuity.

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

    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.

  1. Ophthalmic halo reduced lenses design

    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.

  2. 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

    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

  3. Determination of heparin on intraocular lens surfaces by ion chromatography.

    Ander, B; Karlsson, A; Ohrlund, A

    2001-05-11

    A sensitive and selective method has been developed for the determination of heparin on heparin coated PMMA, poly(methyl methacrylate), intraocular lenses. Heparin was hydrolysed to glucosamine and glucuronic acid, and the content of glucosamine was determined using ion chromatography with pulsed amperometric detection. In order to verify that a complete hydrolysis was obtained for the heparin on the coated intraocular lenses, electron spectroscopy for chemical analysis (ESCA) was used for analysing traces of sulphur on the lens surfaces. The sensitivity of the method allows quantitative determination of 150 ng of heparin on one individual lens. The new method was compared to a standard spectrophotometric method, measuring the colour intensity of a heparin toluidine blue complex. Correlation between the methods was shown for samples prepared from PMMA lenses coated with different amounts of heparin. PMID:11403462

  4. Radiation sensitive acrylate composition

    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

  5. The Visual Effects of Intraocular Colored Filters

    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.

  6. Accuracy of Intraocular Lens Power Formulas Involving 148 Eyes with Long Axial Lengths: A Retrospective Chart-Review Study

    Chong Chen; Xian Xu; Yuyu Miao; Gaoxin Zheng; Yong Sun; Xun Xu

    2015-01-01

    Purpose. This study aims to compare the accuracy of intraocular lens power calculation formulas in eyes with long axial lengths from Chinese patients subjected to cataract surgery. Methods. A total of 148 eyes with an axial length of >26 mm from 148 patients who underwent phacoemulsification with intraocular lens implantation were included. The Haigis, Hoffer Q, Holladay 1, and SRK/T formulas were used to calculate the refractive power of the intraocular lenses and the postoperative estimated...

  7. Controversies in intraocular lens implantation in pediatric uveitis.

    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

  8. Bilateral Primary Intraocular Lymphoma

    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.

  9. Development and experimental verification of an intraocular scattering model

    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.

  10. Bilateral intraocular dirofilariasis

    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.

  11. Bilateral Primary Intraocular Lymphoma

    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...

  12. Cluster Lenses

    Kneib, Jean-Paul; 10.1007/s00159-011-0047-3

    2012-01-01

    Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining...

  13. 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

    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...

  14. Interactions of benzalkonium chloride with soft and hard contact lenses

    We measured the uptake and washout of benzalkonium chloride, using radioactive tracer, by representative hard and soft contact lenses. Uptake by soft contact lenses after 7 days of continuous exposure is high (30 to 56 micrograms/mg of lens weight), with a low percentage of washout in 24 hours (between 0.2% and 1.5% of total uptake). High-water content lenses absorb greater quantities of benzalkonium than do low-water content lenses. Hard lenses take up a much smaller quantity of benzalkonium but release between 30% and 60% of total uptake during washout for 24 hours. Fluorosilicone-acrylate polymer lenses adsorb and release the most preservative, while polymethylmethacrylate lenses (Paragon Optical Inc, Mesa, Ariz) adsorb and release the least. The released benzalkonium from either soft or hard lenses is of a sufficient concentration to be at or above the upper limits of safety

  15. [The progress of studies on intraocular lens implantation in cataract with high myopia].

    Liu, Xue; Wan, Xiuhua

    2015-07-01

    With development of the technology of cataract surgery, combined phacoemulsification and intraocular lens implantation in cataract with high myopia has been widely carried out in clinical treatment. Due to the particularity of high myopia, phacoemulsification in patients with cataract and high myopia is difficult and has recently received a lot of attentions. In this paper, preoperative examinations, the selection of intraocular lenses, surgery methods and surgical complications of cataract surgery in patients with cataract and high myopia are briefly reviewed. PMID:26310259

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

    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.

  17. Synthesis of acrylic prepolymer

    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)

  18. 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

    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

  19. 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

    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

  20. Ophthalmic Lenses

    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,

  1. Probable edge defect in Acrysof single-piece intraocular lens

    Shah Urmi

    2006-01-01

    Full Text Available The purpose of this article is to report an edge defect in single-piece hydrophobic acrylic intraocular lens (IOL observed during a routine phacoemulsification procedure. The chip was successfully removed intraoperatively with a McPherson′s forceps. However, six months postoperatively patient complained of a disturbing glare due to posterior capsular folds originating from the site of IOL defect. Patient was advised, however refused to undergo Nd:Yag laser capsulotomy to relieve the symptoms. This case highlights the necessity to check each foldable IOL under the microscope before loading it into the cartridge, for possible edge defects.

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

    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. Smart lenses

    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.)

  4. Acoustic lenses

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

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

    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.

  6. Silicone/Acrylate Copolymers

    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.

  7. Malignant intraocular tumors

    The role of the radiation therapist in the management of malignant intraocular tumors is changing. With more active identification of malignant intraocular tumors, and a better recognization of the manner in which one can deal with problems of radiation sensitivity, radiation techniques of all sorts will be more actively employed in the treatment of these tumors. Special techniques must be selected for appropriate circumstances of management in order to diminish to an absolute minimum the impact upon the lens, the impact upon visual acuity and the impact upon the cornea. Cobalt-60 plaques are being used more commonly in the treatment of melanomas of the choroid, and the role for radiation therapy in the management of retinoblastoma is changing markably to where it may be used as the primary treatment program rather than enucleation. In metastatic disease involving the uveal tract, radiation therapy has assumed the most important role for management. Chemotherapy should be considered as an active adjuvant in the management of not only those individuals with retinoblastoma but also in those identified circumstances where metastases to the uveal tract are being treated. The role for chemotherapy or immunotherapy in malignant melanoma is unclear

  8. Optical quality of hyperopic and myopic phakic intraocular lenses

    Cari Pérez-Vives

    2014-01-01

    Full Text Available Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D and two hyperopic V4b ICLs (+3 and +6D were measured in vitro. To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS of total higher order aberrations (HOAs, trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs of each ICL evaluated were calculated from the wavefront aberrations at 3- and 4.5-mm pupil. Statistical Analysis: A Student′s t-test for unpaired data was used for comparison between myopic and hyperopic ICLs. Results: Myopic ICLs showed negative spherical aberration, in contrast hyperopic ICLs showed positive spherical aberration, which increases when the ICL power increases, due to the innate optical properties of the lens. All ICLs evaluated had negligible amounts of other aberrations. We did not find statistical significant differences in any Zernike coefficient RMS values analyzed between myopic and hyperopic ICLs at 3- and 4.5-mm pupil (P > 0.05. Conclusions: Myopic and hyperopic ICLs provide good and comparable optical quality for low to moderate refractive error. The ICLs evaluated showed values of wavefront aberrations clinically negligible to affect the visual quality after implantation.

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

    ... 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 ...

  10. Silicone oil-intraocular lens interaction: which lens to use?

    McLoone, E; Mahon, G; Archer, D.; Best, R

    2001-01-01

    AIM—To determine a suitable intraocular lens for implantation in patients at high risk of lens exposure to silicone oil in their lifetime.
METHODS—PMMA, AcrySof, AR40, AQUA-Sense, and Raysoft lenses were examined. Each lens was immersed for 5 minute intervals in balanced salt solution (BSS), in stained silicone oil, and again in BSS before being photographed in air and in BSS. Percentage silicone oil coverage of the lens optic was determined.
RESULTS—The mean percentage coating (MPC) for the ...

  11. Contact Lenses for Vision Correction

    ... 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 ...

  12. Intraocular coenurosis: a case report.

    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.

  13. Acrylic vessel cleaning tests

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

  14. Neutrino Lensing

    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.

  15. Acrylic purification and coatings

    ,

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

    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...

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

    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...

  18. Cataract surgery to lower intraocular pressure

    Berdahl John

    2009-01-01

    Full Text Available Cataract and glaucoma are common co morbidities. Cataract surgery is frequently performed in patients with glaucoma. In this study, a review of literature with search terms of cataract, glaucoma and intraocular pressure is followed by evaluation and synthesis of data to determine the effect of cataract surgery on intraocular pressure. Cataract surgery seems to lower intraocular pressure on a sustained basis, especially in patients with higher preoperative intraocular pressure. The mechanism of action of these finds remains speculative.

  19. Hyperbranched urethane-acrylates

    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.

  20. [Aberration corrected intraocular lens for microincision cataract surgery (MICS). Intraindividual comparison with a conventional lens - 1-year follow-up].

    Möglich, M; Häberle, H; Pham, D T; Wirbelauer, C

    2009-10-01

    Microincision cataract surgery (MICS) is an important advancement in the field of cataract surgery. This article compares an aberration corrected hydrophilic acrylic intraocular lens (IOL) having a hydrophobic surface for MICS with a one-piece hydrophobic acrylic IOL with respect to capsule sac stability, image quality, and after-cataract formation over the course of 1 year. The operations were performed as bimanual MICS or coaxial phacoemulsification. Overall the results after implantation of the IOL by MICS can be regarded as positive in comparison to the standard operation. PMID:18836727

  1. Broadband waveplate lenses.

    Tabiryan, Nelson V; Serak, Svetlana V; Nersisyan, Sarik R; Roberts, David E; Zeldovich, Boris Ya; Steeves, Diane M; Kimball, Brian R

    2016-04-01

    We report on lenses that operate over the visible wavelength band from 450 nm to beyond 700 nm, and other lenses that operate over a wide region in the near-infrared from 650 nm to beyond 1000 nm. Lenses were recorded in liquid crystal polymer layers only a few micrometers thick, using laser-based photoalignment and UV photopolymerization. Waveplate lenses allowed focusing and defocusing laser beams depending on the sign of the circularity of laser beam polarization. Diffraction efficiency of recorded waveplate lenses was up to 90% and contrast ratio was up to 500:1. PMID:27137003

  2. Gravitational Lensing in Astronomy

    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. 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

    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...

  4. [Acrylic resin removable partial dentures

    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

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

    Martina Brandner

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

  6. Cosmology with Doppler Lensing

    Bacon, David; Andrianomena, Sambatra; Clarkson, Chris; Bolejko, C.; Maartens, Roy

    2014-01-01

    Doppler lensing is the apparent change in object size and magnitude due to peculiar velocities. Objects falling into an overdensity appear larger on its near side, and smaller on its far side, than typical objects at the same redshifts. This effect dominates over the usual gravitational lensing magnification at low redshift. Doppler lensing is a promising new probe of cosmology, and we explore in detail how to utilize the effect with forthcoming surveys. We present cosmological simulations of...

  7. 21 CFR 886.3600 - Intraocular lens.

    2010-04-01

    ... the natural lens of an eye. (b) Classification. Class III. (c) Date PMA or notice of completion of a... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens. 886.3600 Section 886.3600 Food... DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification....

  8. Acrylic Acid and Esters Will Be Oversupply

    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.

  9. Automatic intraocular lens segmentation and detection in optical coherence tomography images.

    Gillner, Melanie; Eppig, Timo; Langenbucher, Achim

    2014-05-01

    We present a new algorithm for automatic segmentation and detection of an accommodative intraocular lens implanted in a biomechanical eye model. We extracted lens curvature and position. The algorithm contains denoising and fan correction by a multi-level calibration routine. The segmentation is realized by an adapted canny edge detection algorithm followed by a detection of lens surface with an automatic region of interest search to suppress non-optical surfaces like the lens haptic. The optical distortion of lens back surface is corrected by inverse raytracing. Lens geometry was extracted by a spherical fit. We implemented and demonstrated a powerful algorithm for automatic segmentation, detection and surface analysis of intraocular lenses in vitro. The achieved accuracy is within the expected range determined by previous studies. Future improvements will include the transfer to clinical anterior segment OCT devices. PMID:23928353

  10. One Episode, Two Lenses

    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…

  11. Cosmology with Gravitational Lensing

    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...

  12. The Orphan Lenses Project

    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.

  13. UV curable lens production using molecular weight controlled PEEK based acrylic oligomer (Ac-PEEK).

    İnan, Tulay Y; Yıldız, Emel; Karaca, Birsen; Dogan, Hacer; Vatansever, Alican; Nalbant, Muhammed; Eken, Koray

    2014-08-01

    We produced UV curable lenses with properties blocking short wave UV light. In the UV-curable formulations, we used an oligomer (Ac-PEEK) with another urethan oligomer (Mw = 2000). Radically active, molecular weight controlled Ac-PEEK was obtained by reacting 2-hydroxyl ethyl methacrylate with molecular- weight- controlled and isocyanate terminated PEEK (Mn = 4500). We characterized all synthesized monomer, oligomer and optical materials with UV/Vis spectrophotometer with interferogram, elemental analyser, mass spectrophotometer, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermal gravimetric analyzer, differential scanning calorimeter, scanning electron microscopy and gas chromatography. Results suggested that newly synthesized oligomer with the structure of PEEK absorbs short wave UV-light. Ageing tests [ISO 11979-5, Ophthalmic implants-intraocular lenses (IOL)-Part 5: Biocompatibility] performed on the IOL materials were successful. High contact angle of the obtained lenses suggests that all lenses were hydrophobic and SEM results revealed that lenses are morphologically homogeneous. Based on all positive properties just mentioned, we safely conclude that the lenses produced in this study are very promising for IOL production. PMID:24796625

  14. Cataract surgery and intraocular pressure.

    Melancia, Diana; Abegão Pinto, Luis; Marques-Neves, Carlos

    2015-01-01

    Cataract surgery is one of the most performed surgeries in the developed world. In addition to its significant impact on visual acuity, phacoemulsification has been hailed as a potential intraocular pressure (IOP)-lowering procedure. While current evidence suggests an overall significant and sustained decrease in IOP to exist after cataract surgery, the specific ocular characteristics that could help predict which patients are likely to benefit from this IOP-lowering effect remain unclear. This definition is important in glaucoma patients if this surgery is to be used in the treatment for this disease. Our review aims to summarize the literature on the subject, depicting possible mechanisms behind this IOP decrease, which type of patients are more likely to benefit from this surgery for IOP-lowering purposes and ultimately help optimizing disease management for the increasing number of patients with concomitant glaucoma and cataract. PMID:25765255

  15. Cytomegalovirus retinitis mimicking intraocular lymphoma

    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

  16. Artiflex versus STAAR® implantable contact lenses for correction of high myopia

    Mohammad Ghoreishi; Amin Masjedi; Kobra Nasrollahi; Aminhossein Rahgozar; Keivan Jenab; Hamid Fesharaki

    2011-01-01

    Purpose : To compare two phakic intraocular lenses, Artiflex and STAAR® implantable contact lens (ICL), in high myopia. Setting : Isfahan Ophthalmology Clinic, Iran. Materials and Methods : In a randomized, prospective clinical trial study, 40 eyes of 20 patients who came to Isfahan ophthalmology clinic to correct their refractive error were examined. Artiflex was inserted in 20 eyes and ICL in the other 20 eyes. After 1 year, uncorrected visual acuity (UCVA), best corrected visual ac...

  17. Cosmology with gravitational lenses

    Falco, E. E.

    2009-05-01

    Gravitational lenses yield a very high rate of return on observational investment. Given their scarcity, their impact on our knowledge of the universe is very significant. In the weak-field limit, lensing studies are based on well-established physics and thus offer a straightforward approach to pursue many currently pressing problems of astrophysics. Examples of these are the significance of dark matter and the density, age and size of the universe. I present recent developments in cosmological applications of gravitational lenses, regarding estimates of the Hubble constant using strong lensing of quasars. I describe our recent measurements of time delays for the images of SDSS1004+4112, and discuss prospects for the future utilizing synoptic telescopes, planned and under construction.

  18. Gravitational lensing of quasars

    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...

  19. COSMOLOGY WITH GRAVITATIONAL LENSES

    Emilio E. Falco

    2009-01-01

    Full Text Available Gravitational lenses yield a very high rate of return on observational investment. Given their scarcity, their impact on our knowledge of the universe is very signi cant. In the weak- eld limit, lensing studies are based on well-established physics and thus o er a straightforward approach to pursue many currently pressing problems of astrophysics. Examples of these are the signi cance of dark matter and the density, age and size of the universe. I present recent developments in cosmological applications of gravitational lenses, regarding estimates of the Hubble constant using strong lensing of quasars. I describe our recent measurements of time delays for the images of SDSS J1004+4112, and discuss prospects for the future utilizing synoptic telescopes, planned and under construction.

  20. Types of Contact Lenses

    ... procedure is primarily used for the correction of myopia (nearsightedness). Overnight Ortho-K lenses are the most ... prescribed maintenance schedule in order to maintain the treatment effect. Your eye care professional will determine the ...

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

    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

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

    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

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

    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

  4. Periocular migration of an intraocular lens.

    Jenkins, C.

    1992-01-01

    A woman presented with a painful eye 6 weeks after cataract extraction and intraocular lens implantation. In the past she had had a sector iridectomy for iris bombé caused by chronic anterior uveitis. On examination the three central corneal sutures were absent, whilst the medial and lateral sutures had broken and were protruding from the section. The eye was quiet and the section intact. Combined clinical and ultrasound examination failed to locate the intraocular lens. Four months postopera...

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

    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.

  6. Intraocular cilia associated with perforating injury

    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.

  7. Weak Gravitational Lensing

    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

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

    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

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

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

    2014-01-01

    , 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...... were found to be substantially improved, where poly(lauryl acrylate) was found to be the superior surface modification, resulting in a conductive composite....

  10. Biopsy techniques for intraocular tumors.

    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

  11. Biopsy techniques for intraocular tumors

    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.

  12. SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

    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.

  13. Weak gravitational lensing

    Hoekstra, H

    2014-01-01

    Luminous tracers have been used extensively to map the large-scale matter distribution in the Universe. Similarly the dynamics of stars or galaxies can be used to estimate masses of galaxies and clusters of galaxies. However, assumptions need to be made about the dynamical state or how well galaxies trace the underlying dark matter distribution. The gravitational tidal ?field a?ffects the paths of photons, leading to observable e?ffects. This phenomenon, gravitational lensing, has become an important tool in cosmology because it probes the mass distribution directly. In these lecture notes we introduce the main relevant quantities and terminology, but the subsequent discussion is mostly limited to weak gravitational lensing, the small coherent distortion of the shapes of distant galaxies by intervening structures. We focus on some of the issues in measuring accurate shapes and review the various applications of weak gravitational lensing, as well as some recent results.

  14. Contact Lenses in the Laboratory.

    Kingston, David W.

    1981-01-01

    Summarizes results of a three-item questionnaire returned by 43 Michigan institutions expressing views on wearing contact lenses in chemical laboratories. Questions focused on eye protection, type of protection, and use of contact lenses. (SK)

  15. Accuracy of Intraocular Lens Power Formulas Involving 148 Eyes with Long Axial Lengths: A Retrospective Chart-Review Study.

    Chen, Chong; Xu, Xian; Miao, Yuyu; Zheng, Gaoxin; Sun, Yong; Xu, Xun

    2015-01-01

    Purpose. This study aims to compare the accuracy of intraocular lens power calculation formulas in eyes with long axial lengths from Chinese patients subjected to cataract surgery. Methods. A total of 148 eyes with an axial length of >26 mm from 148 patients who underwent phacoemulsification with intraocular lens implantation were included. The Haigis, Hoffer Q, Holladay 1, and SRK/T formulas were used to calculate the refractive power of the intraocular lenses and the postoperative estimated power. Results. Overall, the Haigis formula achieved the lowest level of median absolute error 1.025 D (P 33 mm, and median absolute errors were significantly higher for those eyes than eyes with axial length = 26.01-30.00 mm. Absolute error was correlated with axial length for the SRK/T (r = 0.212, P = 0.010) and Hoffer Q (r = 0.223, P = 0.007) formulas. For axial lengths > 33 mm, eyes exhibited a postoperative hyperopic refractive error. Conclusions. The Haigis and SRK/T formulas may be more suitable for calculating intraocular lens power for eyes with axial lengths ranging from 26 to 33 mm. And for axial length over 33 mm, the Haigis formula could be more accurate. PMID:26793392

  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

    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.

    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. Gravitational Lensing & Stellar Dynamics

    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.

  19. Nonparaxial anamorphic diffractive lenses

    Applications of anamorphic diffractive lenses, or in other words elliptical zone plates, are growing in number and diversity. Following this progress, the manufacturing methods of anamorphic diffractive lenses are also a subject of continuous improvement. On the other hand, their design is still based mainly on the paraxial approximation. In the present paper nonparaxial elliptical zone plates are presented and their difference from the paraxial version, termed as the elliptical aberration is shown. A comparison of their focusing quality was performed based on results of numerical modelling as well as experiments. (paper)

  20. Weak and Strong Lensing Statistics

    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.

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

    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.

  2. 21 CFR 886.4300 - Intraocular lens guide.

    2010-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device intended to be inserted into the eye during surgery to direct... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens guide. 886.4300 Section...

  3. Gold Nanoslit Lenses

    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

  4. Fresnel's Lighthouse Lenses

    Greenslade, Thomas B., Jr.

    2007-01-01

    One of the rewards of walking up the scores of steps winding around the inside of the shaft of a lighthouse is turning inward and examining the glass optical system. This arrangement of prisms, lenses, and reflectors is used to project the light from a relatively small source in a beam that can be seen far at sea.

  5. Feline intraocular sarcoma associated with phthisis bulbi

    E. Perlmann

    2011-06-01

    Full Text Available Two cases of feline intraocular sarcoma were reported in stray cats that presented blindness and hypotonia of the affected eye for years before the tumor development. Phthisis bulbi, a final stage of a severe inflammation of the eye, is frequently unmonitored because eyes are blind, small, opaque, and not painful. Yet, this report shows that monitoring and early enucleation of eyes of cats with phthisis bulbi are important and should be considered as a treatment option, because feline intraocular sarcoma is an aggressive tumor that significantly decreases live expectancy.

  6. Radiation curing silicone acrylate systems

    Radiation curing silicone systems by either ultra violet light (UV) or electron beam (EB) is introduced. The cure is based on the polymerization of the acrylic C = C double bond via a radical chain reaction. In the EB curing process a sufficient number of radicals for spontaneous polymerization is produced due to the high radiation energy whereas with UV light the energy is not as intensive thus a photo-initiator is required for a UV process. The required high local radical concentration provided by its decay. The radical generation immediate chain-growing leads to rapid and efficient crosslinking even at room temperature. It is for this reason that silicone acrylates cure immediately. All coater capable of handling 100% thermally curing silicones are suitable for the use with Goldschmidt's RC systems

  7. Treatment of ophidism-induced bilateral canine cataract by extracapsular lens extraction and intraocular lens implantation.

    Kibar, M; Evereklioğlu, C; Doğan, Z

    2014-01-01

    The aim of this study was to report a new cause of cataract, namely snake bite induced cataract in a dog. A 3-year-old male mongrel dog was referred to our clinic for the assessment of cataract in both eyes. The dog was bitten by a snake nearly 4 months ago. A 40 dioptre acrylic lens with 13 mm haptics was implanted into the lens capsule. In the left eye, posterior synechia was detected in the temporal part of the iris, but decentration of the intraocular lens was not observed. To the best of our knowledge, this is the first report of bilateral cataract caused by ophidism and treated by surgical intervention in a dog. PMID:27175143

  8. Bilateral spontaneous anterior dislocation of intraocular lens with the capsular bag in a patient with pseudoexfoliation

    Harsha Bhattacharjee

    2015-01-01

    Full Text Available We report a rare case of bilateral spontaneous anterior partial in-the-bag intraocular lens (IOL dislocation in a 75-year-old man with pseudoexfoliation (PXF. He underwent uneventful phacoemulsification in both eyes with in-the-bag IOL implantation 9 years back. In the right eye, single piece poly (methyl methacrylate (PMMA IOL (+19 D and in the left eye, single piece acrylic foldable IOL (+19 D were implanted. An attempt at pharmacological IOL repositioning was unsuccessful. The dislocated IOLs were explanted and exchanged with scleral suture fixated PMMA IOLs. Vision improved to 20/30 in both eyes following surgery, without any associated ocular morbidity. We believe that zonular weakness secondary to PXF, capsular contraction, and myopia together were the predisposing factors for partial anterior dislocation of IOLs and IOL exchange with scleral suture fixation of IOL is a safe and effective treatment option.

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

    Fernanda Teixeira Krieger

    2006-08-01

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

  10. Capsulorhexis contraction after cataract surgery

    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...

  11. Learning unit: Thin lenses

    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

  12. Characterizing intraocular tumors with photoacoustic imaging

    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.

  13. Radiation curing applications of palm oil acrylates

    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)

  14. Pulsar lensing geometry

    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...

  15. Management of dislocated intraocular implants.

    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

  16. Gravitational lensing by wormholes

    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.

  17. Hydrogels contact lenses

    Michálek, Jiří; Hobzová, Radka; Přádný, Martin; Dušková, Miroslava

    New York : Springer, 2010 - (Ottenbrite, R.; Park, K.; Okano, T.), s. 303-315 ISBN 978-1-4419-5918-8 R&D Projects: GA AV ČR KAN200520804 Institutional research plan: CEZ:AV0Z40500505 Keywords : contact lenses * hydrogels * silicone-hydrogels Subject RIV: EI - Biotechnology ; Bionics http://www.springerlink.com/content/l32kx3303v110unn/

  18. Noiseless Gravitational Lensing Simulations

    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...

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

    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

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

    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...

  1. Acrylates and methacrylates of formal-glycerine

    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.

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

    Francesco Semeraro

    2014-01-01

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

  3. Weak lensing by voids in modified lensing potentials

    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 ...

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

    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, ...

  5. Intraocular pressure in Japanese diabetic patients

    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. Intraocular eyelash after uneventful cataract surgery

    Knyazer, Boris

    2010-01-01

    Boris Knyazer, Jaime Levy, Itamar Klemperer, Tova LifshitzDepartment of Ophthalmology, Soroka University Medical Center, Ben-Gurion, University of the Negev, Beer-Sheva, IsraelIntroduction: Intraocular eyelash is an uncommon complication after cataract surgery. We report a very rare case of corneal foreign body after uneventful phacoemulsification surgery. Methods: A 66-year-old man referred to our outpatient ophthalmology clinic for routine examination one week after uneventful phacoemulsifi...

  7. RHIC electron lenses upgrades

    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.

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

    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

  9. Effect of a tight necktie on intraocular pressure

    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...

  10. Magnetic electron lenses

    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...