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Retention durability, especially in the eye, is one of the most important properties of ophthalmic viscosurgical devices (OVDs) during ocular surgery. However, the information on the physical properties of OVDs is insufficient to explain their retention durability. The purpose of this study is to clarify the mechanism of OVD retention to improve understanding of the behavior of OVDs during ocular surgery. To elucidate the mechanism of OVD retention, we have developed a new test method for measuring repulsive force. As a result, the maximum repulsive force of OVDs was positively and well correlated with the retention durability of investigated OVDs. Consequently, we demonstrated that the repulsive force could be used as an index of retention durability on the ocular surface and in the eye. We directly compared the intraocular retention durability of three OVDs (Shellgan, Viscoat, and Opegan-Hi) in ex vivo porcine eyes. Opegan-Hi was immediately removed from the anterior chamber, but Shellgan and Viscoat remained largely in the anterior chamber as determined by fluorescence imaging. These results showed that the intraocular retention behavior of OVDs was similar to their ocular surface behavior in our previous report, suggesting that retention durability is dependent on the OVD itself. The retention durability of Shellgan seemed to be higher than that of Viscoat, and the maximum repulsive force of Shellgan was 1.35-fold higher than that of Viscoat. Therefore, the repulsive force might be a useful index for assessing the difference in the retention durability between OVDs such as Shellgan and Viscoat.

Purpose To evaluate the effects of D-sorbitol addition on changes in the extrusion force of ophthalmic viscosurgical devices (OVDs). Methods OVD formulations; the mixtures of 3% hyaluronic acid (HA) and 4% chondroitin sulfate (CS) containing 0%, 0.5%, or 1.0% D-sorbitol were prepared. Each prefilled syringe of OVD was stored at room temperature for 0, 15, 30, 60, or 120 mins after a small amount of viscoelastic agent was discharged from the needle. The extrusion force values (kgf) of these OVDs when reused after storage were measured with a texture analyzer. Moreover, 10 healthy adults (5 men and 5 women) used a pinch sensor to measure the extrusion force values for the HA/CS combination without D-sorbitol which was stored in the above manner, and used a 4-step scale to score the usability of OVD. Results For the HA/CS combination without D-sorbitol, the extrusion force value was increased from its initial value (storage duration, 0 min) as storage duration increased. However, for the HA/CS combination containing 0.5% or 1.0% D-sorbitol, this value remained almost unchanged over time. Likewise, the pinch sensor-determined extrusion force values of HA/CS combination without D-sorbitol increased, depending on storage duration. Conclusion The addition of D-sorbitol to viscoelastic agent may suppress the needle clogging that occurs with OVD storage, and may improve the usability of OVDs during surgery.

Purpose To compare the effect of decentration and tilt on the optical performance of 6 aspheric intraocular lens (IOL) designs in a model eye. Setting Department of Ophthalmology, Graduate School of Medicine, Dokkyo Medical University, Tochigi, Japan. Design Experimental study. Methods In theoretical simulations, the amount of spherical aberration in the IOL was varied to produce residual ocular spherical aberration (range −0.15 to 0.30 μm) at a 6.0 mm entrance pupil. Wavefront aberration analyses were performed with the ZEMAX optical design program (version August 20, 2014) to obtain the ocular root-mean-square values of astigmatism, coma, trefoil, and higher-order aberrations (HOAs) when the IOL was centered on the insertion position and misaligned at a 4.0 mm entrance pupil. The retinal visual images were calculated using the same conditions. Six 20.0 diopter (D) aspheric IOLs and one 20.0 D spherical IOL were used for the experimental studies. Each IOL was inserted in the model eye. The actual alignments were measured using a Scheimpflug camera (EAS-1000). The wavefront aberrations and visual images were gauged using a wavefront analyzer (KR-1W) at several IOL alignments. Results Intraocular lens decentration and tilt increased wavefront aberrations and degraded optical performance. Astigmatism, coma, and HOAs generated by misaligned IOLs were related to the amount of spherical aberration correction of the IOLs. The extent of spherical aberration remained unchanged by the amount of misalignment. Experimental model eye results showed trends similar to theoretical results. Conclusions The spherical aberration correction amount in the aspheric IOL design was critical for the astigmatism, coma, and HOAs generated by the IOL misalignment. Additional spherical aberration corrections led to a more sensitive optical performance degradation resulting from IOL misalignment.

To disclose histological advantages of intrascleral fixation of intraocular lens haptics, in comparison with scleral suture fixation, in a study with rabbits. Ten white rabbits, 10 weeks of age, were used in this experimental histopathological study. After unilateral lensectomy and anterior vitrectomy, an intraocular lens haptic was inserted into one eye of each rabbit. Intrascleral fixation was performed in five rabbits, whereas scleral suture fixation was performed in the others. At postoperative 1 week, the globe was enucleated in two rabbits in each group; at postoperative 8 weeks, the globe was enucleated in the remaining three rabbits in each group. Sections of the sclera around haptics and sutures were evaluated with haematoxylin and eosin and immunohistochemical staining methods. We assessed severity of inflammation on histopathological photos, taken near the haptic or suture in the sclera, by counting white blood cells. The Mann-Whitney U test was performed to analyse differences in the severity of inflammation between the groups. Samples in the intrascleral fixation group demonstrated reduced irregularity of collagen fibres; reduced infiltration of fibroblasts, giant cells, lymphocytes, neovascular cells, neutrophils and eosinophils and weaker staining for fibronectin (indicating tissue repair) and heat shock protein 70 (indicating cell damage). In addition, reduced white blood cell infiltration was observed in the intrascleral fixation samples at 8 weeks in both shallow sclera (p = 0.001) and deep sclera (p = 0.002). Histological analysis showed that intrascleral fixation caused fewer inflammatory changes than scleral suture fixation, with reduced fibroblast migration and production of cytotoxic factors.

Purpose To develop a single-piece open-capsule intraocular lens (IOL) that can be inserted through a small incision and that prevents posterior capsule opacification (PCO) by expanding the capsule and circulating aqueous humor into the capsular bag. Setting Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. Design Experimental study. Method Using the same hydrophobic acrylic material as the NY-60 IOL, a prototype open-capsule IOL was constructed. The IOL has a single optic and 2 haptics, with a 2.8 mm high spacer and holes through which aqueous humor circulates into the capsular bag by separating the anterior capsule from the posterior capsule and expanding the capsule. The open-capsule IOL or NY-60 (as a control group) was inserted in rabbit eyes. Posterior capsule opacification development was evaluated by measuring the thickness of the cell layer at the center of the posterior capsule on histopathologic specimens and statistically comparing the thickness between the open-capsule IOL group and control group. Results The open-capsule IOL could be inserted through a 3.2 mm corneal incision using a D cartridge. The mean thickness of the cell layer at the center of the posterior capsule was 4.78 μm ± 2.61 (SD) in the open-capsule IOL group and 101.14 ± 25.19 μm in the control group and was significantly smaller in the open-capsule IOL group. Conclusion The prototype single-piece IOL could be implanted through a small incision and prevented PCO by expanding the lens capsule and circulating aqueous humor into the capsular bag.

Background To report on five patients with decreased visual acuity due to glistening and severe sub-surface nano-glistening (SSNG) formation within their intraocular lenses (IOLs). Design Case reports and analysis of extracted IOLs. Participants and samples We report improved visual acuity when IOLs with severe glistening and SSNG were exchanged for clear IOLs in five patients. Methods Case reports. Main outcome measures The main outcome measure was visual acuity. The secondary outcome measure was light transmission. Explanted IOLs were subjected to investigation. Pre- and postoperative slit lamp images of the anterior eye and microscopic images of the extracted IOLs were taken and compared. Light transmission of the IOL was measured using a double beam type spectrophotometer. An integrated value of the percentage light transmittance in the visible light spectrum was calculated. Results We report on five patients whose visual acuity improved when IOLs were exchanged because of severe glistening and SSNG. All of the affected IOLs were MA60BM (Alcon, Forth Wroth Texas, USA) and the original implantation had occurred over a range of 6–15years prior to the IOL exchange. Light transmission was decreased in all affected lenses compared to a similar control IOL. Conclusions Although only a few reports of cases in which glistening and SSNG have progressed to the level of decreased visual function have been published, the likelihood is that this phenomena will increase as the severity and incidence of these inclusions have been shown to increase with time. Appropriate evaluations of visual function in such patients are needed and consideration should be given to IOL exchange in symptomatic patients.

Purpose To evaluate whether and how intraocular lens (IOL) implantation influences the development of anterior capsule contraction and posterior capsule opacification (PCO). Setting Department of Ophthalmology, Dokkyo Medical University, Mibu, Tochigi, Japan. Design Experimental study. Methods Phacoemulsification was performed in 8-week-old white rabbits. A hydrophobic acrylate IOL (12.5 mm) (YA-60BBR) was implanted in 1 eye and no IOL was implanted in the fellow eye. Slitlamp microscopy and anterior segment analysis were performed to evaluate anterior capsule contraction after the surgery. Four weeks postoperatively, sections of the eyes were made, and the thickness of the proliferated lens epithelial cell (LEC) layer at the posterior capsule was measured to assess the PCO. In addition, LECs from white rabbits were cultured in medium containing 50% aqueous humor or in medium containing 50% saline to determine the influence of the aqueous humor on LECs and to compare the degree of LEC proliferation. Results Starting 2 weeks after surgery, anterior capsule contraction progressed more significantly in the IOL group than in the group without IOLs. Four weeks postoperatively, LEC thickness at the posterior capsule was significantly less in the group without IOLs than in the IOL group. In the culture study, LEC proliferation was more inhibited in the aqueous humor group than in the saline group. Conclusions Progression of anterior capsule contraction and PCO is less likely in aphakic eyes than in IOL-implanted eyes. The mechanism of prevention may involve aqueous humor–induced inhibition of LEC proliferation. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Aims: To report the incidence of infectious and noninfectious endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor (VEGF) from a multicenter clinical trial in Japan. Methods: A retrospective multicenter review of the data of patients who received intravitreal anti-VEGF injections between January 2007 and March 2011 was undertaken. Cases with the clinical diagnosis of endophthalmitis resulting from intravitreal injection were identified and reviewed. Results: A total of 5,236 intravitreal anti-VEGF injections (1,209 intravitreal injections of bevacizumab, 3,827 injections of ranibizumab, and 200 injections of pegaptanib sodium) had been administered. Five patients (0.095%), all of whom had received bevacizumab, were diagnosed as having endophthalmitis after the intravitreal injection. All patients visited the institutes for re-examination within 1–2 days after the injection. Among the 5 patients, 2 (0.038%) were culture positive for Streptococcus oralis and Enterococcus faecalis, respectively. The remaining 3 eyes (0.057%) developed presumed noninfectious endophthalmitis. Conclusion: Although endophthalmitis is a rare complication associated with intravitreal injection, in this series intravitreal anti-VEGF injection caused infectious or noninfectious endophthalmitis at a relatively high frequency. Further investigations are needed to consider an appropriate injection protocol for minimizing the incidence rates of endophthalmitis, and to assess the optimal treatment protocol for intravitreal injection-related endophthalmitis although it was difficult to differentiate these two entities.

Advances in intraocular lens (IOL) design have led to the use of lenses with improved performance including tinting, asphericity, multifocality and accommodation. To maximize the visual performance of these IOLs, postoperative complications such as secondary cataracts and anterior capsule contraction must be prevented. Various types of secondary cataracts may occur, each associated with complex biological reactions. Different design configurations, including square-edge IOLs, have been used to prevent secondary cataracts and anterior capsule contraction, but these have not been successful in sufficiently eliminating these complications. We have found that surface modification of IOL surfaces chemically improves surface quality and is also useful in preventing secondary cataracts and anterior capsule contraction. The UV/ozone treatment that we used as a surface modification method is a simple and highly effective method with no safety issues regarding materials following treatment. The combination of square-edge design and surface modification may be able to completely eliminate these postoperative complications.

Purpose To evaluate active oxygen processing on the surface of acrylic intraocular lenses (IOLs) to prevent secondary posterior capsule opacification (PCO). Setting Department of Ophthalmology, Dokkyo Medical University School of Medicine, Mibu City, Tochigi, Japan. Methods Acrylic IOLs were prepared, and ultraviolet (UV)/ozone (UV/O 3 ) or argon plasma was irradiated to the surface of the IOLs. Elemental analysis (electron spectroscopy for chemical analysis [ESCA]) of the IOL surfaces was performed to confirm surface modification. Changes produced by UV/O 3 or argon plasma treatment were examined for fibronectin and lens epithelial cell (LEC) adhesion. To evaluate the PCO prevention by treated IOLs, 8-week-old albino rabbits were used. The rabbit eyes randomly had phacoemulcification and implantation of 3 different IOLs: the UV/O 3 -treated IOLs, argon plasma–treated IOLs, and the control IOLs. After 2 weeks, the rabbits were killed and their globes were dissected and fixed using formaldehyde 10%. The PCO was observed using light microscopy (DX51, ORIMPUS) after hematoxylin and eosin staining. Results Comparison of IOL surface composition by ESCA showed an increase in nitrogen content and hydroxyl substitute and carboxyl substitute groups on surfaces of treated IOLs. The fibronectin adhesion and the LEC adhesion on the UV/O 3 -treated and argon plasma–treated samples were increased. In the untreated group, there was statistically significant inhibition of PCO formation in the UV/O 3 -treated and argon plasma–treated groups. Conclusion Active oxygen processing and argon plasma irradiation on the surface of IOLs was effective in preventing secondary PCO after cataract surgery.

* BACKGROUND AND OBJECTIVE: Secondary posterior subcapsular opacification is still among the most important complications after phacoemulsification. * MATERIALS AND METHODS: This study was designed to assess the inhibitory effects of drugs delivered via hydrophilic acrylic (hydrogel) intraocular lens (IOL) systems in vitro. Lens epithelial cells were collected from albino rabbits. The following seven groups of hydrogel IOLs were prepared: untreated IOLs and IOLs infiltrated with diclofenac sodium, tranilast, mitomycin C, colchicines, 5-fluorouracil, and ethylenediaminetetraacetic acid. The IOLs were fixed to a Cell Culture Insert; they were then bathed and incubated in minimum essential medium containing cultured lens epithelial cells. Subsequently, a comparative analysis of the cells adhering to the collagen membrane and the lens surfaces was conducted. * RESULTS: Adhesion of lens epithelial cells to the lens surfaces and the collagen membrane was observed in the control group. However, only slight cellular adhesion was found on the surfaces of the IOLs and on the collagen membrane in the treated IOL groups. * CONCLUSION: Use of hydrogel IOLs infiltrated with drugs was associated with inhibition of posterior subcapsular opacification in vitro. [Ophthalmic Surg Lasers Imaging 2005;36:386-392.]

To analyze the effect of calcium on human lens epithelial cells (LECs) in vitroHuman LECs were obtained from the anterior lens capsule during a cataract operation, and were cultured in minimum essential medium (MEM) containing 12% fetal bovine serum for a week at 37 degrees C, 5% CO(2). The LECs were then isolated with trypsin and placed in culture dishes. To analyze the effects of calcium, the LECs were incubated in MEM with calcium concentrations of 0, 2, 10, or 20 mM. After HE staining for 72 h, the LECs were analyzed with the Scion imaging program.The LECs proliferated rapidly and their shapes were uniform in 2-mM-calcium MEM. The LECs proliferated more slowly and had irregular shapes in MEM with lower and higher concentrations of calcium.Calcium affects both the proliferation and the shape of human LECs in culture. Abnormal (hyper- or hypo-) calcium concentrations in the lens and aqueous humor may change the homeostasis of LECs, resulting in cataracts and secondary posterior capsular opacification.

Purpose: To analyze selected lens cytoskeletal proteins in posterior capsule opacification (PCO) 2 weeks after intraocular lens (IOL) implantation in rabbits. Setting: Department of Ophthalmology, Dokkyo University School of Medicine, Tochigi, Japan. Method: Eight 10-week-old albino rabbits were prepared and anesthetized for phacoemulsification and aspiration of the crystalline lens and implantation of an acrylic or a hydrogel IOL. Two weeks postoperatively, the rabbits were killed and the IOLs removed for immunohistochemistry. Deparaffinized tissue sections were processed with antibodies against α-smooth muscle actin (α-SMA) and β-crystallin to observe the types of PCO with the 2 IOL types. The proteins in the PCO tissue and the normal lens were homogenized, centrifuged, and analyzed using SDS-polyacrylamide gel electrophoresis (SDS-PAGE) densitometric analysis and Western immunoblotting for actin and vimentin. Results: Immunohistochemistry demonstrated a fibroblastic cell type expressing α-SMA and partial regeneration of epithelial cells, resulting in a lenticular structure that stained irregularly for β-crystallin. The immunoreactivity of fibroblast-like cells to β-crystallin appeared weaker than that of the regenerated lenticular structure. SDS-PAGE showed variability in the content of cytoskeletal proteins in the insoluble fractions of the PCO. Degradation of the cytoskeletal components was greater with the acrylic IOL than with the hydrogel IOL. Conclusion: Cytoskeletal proteins expressed during the formation of PCO and IOL implantation may have potential as therapeutic target proteins to improve the biocompatibility of IOLs.

This study of lens protein composition found that some cytoskeletal proteins were degraded during the earliest stages of cataract formation. Cataract was induced in 13–14 day old rats by a single subcutaneous injection of sodium selenite (19 μmol kg −1 ). By 24 hr after the injection of selenite, the ratio of insoluble to soluble protein increased as lens opacification began. The increase in insoluble protein aggregates was correlated with an accelerated loss of proteins having molecular weights of 42, 55/57 and 235 kDa which reacted with antibodies to the cytoskeletal proteins actin, tubulin/vimentin and spectrin, respectively. We observed the loss of 49, 60 and 90 kDa proteins which were not identified. In the lenses of animals protected from protein aggregation and opacification by administration of 1.5 mmol kg −1 pantethine, the pattern of proteins in SDS-PAGE gels resembled the pattern for proteins from transparent lenses of normal untreated animals and loss of cytoskeletal proteins was prevented.

Purpose To clinically evaluate postoperative changes in the transparency of hydrophobic acrylic intraocular lenses (IOLs). Setting Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. Design Case-control study. Methods Eyes having phacoemulsification were randomly assigned to have implantation of 1 of 3 hydrophobic acrylic IOL models. The IOLs were photographed at 0 degree and 90 degrees 1 week, 6 months, and 1 year after implantation using a Nidek EAS-1000 anterior chamber analyzer in slit mode. The images were used to determine the intensity of light scattering in the surface and middle regions of the IOL optic. Results The study comprised 65 eyes of 57 patients with a mean age of 72.5 years. The rate of increase in light-scattering intensity was similar in the middle and surface regions of the Tecnis ZA9003 aspheric IOL. The increase in light-scattering intensity in both regions of the AF-1 VA-60BB spherical IOL was greater than that in the aspheric IOL at all the measurement points. The intensity of light scattering was highest and tended to increase over time in both regions of the AcrySof SA60AT spherical IOL; the rate of increase in intensity was higher in the surface region than in the middle region, and the difference was significantly greater at 6 months and 1 year than at 1 week. Conclusion Our results suggest that AcrySof SA60AT and AF-1 VA-60BB IOLs are likely to develop glistenings over time and that the former may develop whitening. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

To investigate the effects of light scattering from the surface of hydrophobic acrylic intraocular lenses (IOLs) on visual function.A 67-year-old man was implanted with an IOL (MA60BM) in January 1998, but became aware of decreased visual function in May 2008. Observation with a slit lamp revealed light scattering throughout the entire optic of the IOL, which was extracted and replaced. Postoperative visual function improved at 1 month. The cause of light scattering was investigated with a focus on water permeating the IOL material. To confirm the effect of light scattering on visual function, light transmission of the extracted IOL was measured in physiological saline at 33 °C, and the simulated retinal image was evaluated in a model eye.Observation of the extracted IOL showed light scattering from the optic surface layer, the main cause of which was phase-separated water within the IOL material. Light transmission in the extracted IOL was 16.3% lower than that in an unused IOL in the visible range. Moreover, the simulated retinal image was hazy compared to that of the unused IOL.Severe surface light scattering from an IOL optic may decrease visual function.

Purpose To identify the cause of light scattering on the surface (ie, whitening) of extracted AcrySof intraocular lenses (IOLs). Setting Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. Methods Dislocated IOLs extracted from 3 patients were stored and the IOL surfaces examined under light microscopy. The effect of whitening on visual function was evaluated by measuring light transmission with a spectrophotometer. To determine the cause of opacification, the IOLs were examined for calcium phosphate deposits using an electron probe X-ray microanalyzer. The IOL surface, including the presence of organic deposits and evidence of hydrolysis, was also examined by Fourier-transform infrared spectrophotometry. The IOLs were then dried, immersed again in physiological saline, and serially examined for changes in opacification. Results The optic surfaces of all IOLs had opacification due to whitening. Light transmission in the visible range of 360 to 800 nm was 4% less than that of unused IOLs. The X-ray microanalysis showed no calcium phosphate deposits. Fourier-transform infrared spectrophotometry of the IOL optic material showed no evidence of hydrolysis. Opacification disappeared after the IOLs were dried and then reappeared over time when the IOL was immersed again in physiologic saline. Conclusions The findings strongly suggest that whitening of the hydrophobic acrylic IOL was due to trace water molecules that infiltrate the optic. Within the 3-dimensional network of the polymeric lens material, the molecules are too small to form observable voids but can form water aggregates of sufficient size to scatter visible light, causing opacification (ie, whitening).

Purpose To evaluate the efficacy of ophthalmic nonsteroidal and steroidal antiinflammatory drugs in preventing anterior capsule contraction and secondary posterior capsule opacification (PCO) using an experimental cataract model. Setting Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. Methods Eight-week-old albino rabbits weighing about 2 kg each had phacoemulsification and intraocular lens implantation. After surgery, the rabbits were divided into 3 treatment groups: diclofenac sodium ophthalmic solution, bromfenac sodium ophthalmic solution, and betamethasone ophthalmic solution. In each group, the ophthalmic solution was applied to the left eye of each rabbit twice daily; the right eye served as an untreated control. To evaluate anterior capsule contraction, the percentage of incised anterior capsule opening area was calculated on diaphanoscopic images obtained with an EAS-1000 anterior segment analyzer. For evaluation of PCO, a tissue section was stained with hematoxylin–eosin and observed under a light microscope. The PCO was quantified on the basis of the thickness of the lens epithelial cell layer on the central subcapsular area and compared among groups. Results Fifteen albino rabbits were used in the study. Treatment with diclofenac sodium and bromfenac sodium ophthalmic solution prevented progression of anterior capsule contraction and PCO. Treatment with bromfenac ophthalmic solution did not prevent either complication. Conclusion Postoperative treatment with ophthalmic nonsteroidal antiinflammatory drug solutions prevented anterior capsule contraction and PCO in rabbit eyes.

Purpose To compare anterior capsule contraction in cataract patients having implantation of 1 of 5 foldable intraocular lens (IOL) models and evaluate lens epithelial cell (LEC) adhesion to each model. Setting Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. Methods This study comprised 115 patients (126 eyes) without systemic or ocular complications who had phacoemulsification with IOL implantation. The eyes were randomly assigned to receive 1 of the following IOLs: acrylic MA60BM (Alcon), SA60AT (Alcon), AR40e (Advanced Medical Optics), or YA-60BBR (Hoya) or a silicone AQ310NV (Canon). Two weeks and 1, 3, and 6 months postoperatively, the anterior capsule opening area was measured using an anterior segment analysis system (EAS-1000, Nidek) and the percentage of anterior capsule contraction was compared for each postoperative period and IOL. Cell adhesion to each IOL type was evaluated using LECs from albino rabbits. Results The mean age of the patients was 73.6 years ± 5.6 (SD). Eyes with the AQ310NV and AR40e IOLs had statistically significantly greater anterior capsule contraction. The rabbit study showed statistically significantly less LEC adhesion on these 2 IOL models. Conclusions Anterior capsule contraction was significantly greater with the AQ310NV and AR40e IOLs than with the other IOLs. Results indicate that cell adhesion to the IOL is an important factor in preventing anterior capsule contraction.

Our results indicate that ECCE conversion can achieve good results. Converting to ECCE because of a dense nucleus or the inability to achieve a continuous curvilinear capsulorhexis seems reasonable, given that in these situations one may be able to perform an ECCE similar to the way it would have been performed had it been planned. However, if vitreous loss is present, the ECCE may result in vitreous traction. It is now generally accepted that anything that could result in vitreous traction during complicated cataract surgery should be avoided. Procedures such as cellulose sponge vitrectomy and wound sweeping with a spatula are no longer considered acceptable because of the inherent traction they produce. Delivery of the nucleus during ECCE can be achieved by “pulling”manually or by “pushing” externally or internally (using balanced salt solution or an ophthalmic viscosurgical device). In the presence of vitreous loss, all these techniques may result in vitreoretinal traction (unless fragments anterior to the posterior capsule are manually removedafter a thoroughanteriorvitrectomy). Many trainees now receive little ECCE training, making the chance of a successful conversion less likely. If ECCE is unsuccessful, subsequent vitreoretinal surgery may be hampered by an enlarged wound and a cornea that may take longer to recover than if ECCE had not been attempted. In light of the above, we currently recommend that conversion to ECCE at our unit be considered only by surgeonswho are trained in ECCE surgery and vitreous loss is neither present nor likely. We hope that future studies will elucidate the role of ECCE conversion and allow surgeons to make more informed decisions.

Background and Purpose: Previous studies used sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to characterize the modifications to lens proteins during opacification in the selenite model for cataract. To analyze the protein modifications in more detail, two dimensional electrophoresis (2 DE), which is more sensitive than 1 D electrophoresis, was used. Results: The results of 2 DE demonstrated rapid changes in cytoskeletal proteins including spectrin and vimentin at the earliest stages of opacification. Conclusion: The results suggested that the mechanism of opacification might involve changes in cytoskeletal proteins during the earliest stages of cataract formation.

Purpose : Approximately 50% of congenital and childhood cataracts seen in the clinic is of undetermined origin. Biochemical analysis of the cataracts is rare. This study analyzes lens proteins to determine the mechanism of congenital and childhood cataracts. Method : We analyzed the lens proteins from 10 young patients after cataract operations, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), densitometry analysis, and Western immunoblotting. Results : Densitometry of separated proteins showed a decrease in the high molecular protein bands of posterior subcapsular cataract (PSC). Specifically, spectrin (235 kDa), filensin (100 kDa), and vimentin (57 kDa) were absent from the SDS-PAGE of PSC. Increases in filensin and vimentin were observed in a Christmas tree cataract and lamellar cataracts. Western immunoblots confirmed the densitometry of SDS-PAGE. Conclusion : These results suggest that changes in cytoskeletal proteins may contribute to congenital and childhood cataracts.

Macaca nemestrina pig-tail macaques were administered daily oral doses of 3.85 or 5.78 mg/kg of cortisol for 1 year. The ages of the macaques were from 19 to 29 years. After 1 year, lenses were observed using a slitlamp ophthalmoscope and the stage of cataract was classified in each eye. Enucleated lenses were analyzed for content of soluble and insoluble proteins. Lens proteins were analyzed using SDS polyacrylamide gel electrophoresis (SDS-PAGE) and the changes in lens proteins were quantified using densitometry of the individual gels. Untreated control lenses were obtained over the range of 4 to 29 years of age and the proteins were analyzed. A slow progressive increase in the cataract stage and in the proportion of insoluble protein aggregates corresponded with the animal age, not the cortisol treatment. The observed changes in the protein components may suggest an important role for cytoskeletal proteins in lens transparency during aging. Exposure to high doses of oral steroids over a period of 1 year did not result in detectable modification of crystallin or cytoskeletal proteins. Even at high doses, longer exposure may be necessary to produce the cataract associated with steroid administration.

Background and Purpose: The cataract in Sprague–Dawley rats injected with selenite is a dense nuclear opacity that appears by 4 or 5 days after selenite injection and becomes irreversible by 7 days. Injection of Wistar rats with selenite resulted in a similar nuclear opacity by 4 or 5 days that began to recover transparency by 7 days. In this report, the cytoplasmic proteins were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in lenses from Sprague–Dawley and Wistar rats at 4 and 7 days after injection. Results: In the opaque lens cells, degradation of the 31 kDa protein and cytoskeletal proteins (vimentin, spectrin, and actin) was observed during cataract development using SDS-PAGE and Western blot analysis. During recovery from opacity, the decreased 31 kDa protein and the vimentin increased. Conclusion: The results suggest that the 31 kDa protein and the vimentin may be important for recovery of transparency in a reversible model of cataract formation.