Hydrophobic acrylic and plate-haptic silicone intraocular lens implantation in diabetic patients: pilot randomized clinical trial.

PURPOSE: To compare the capsular and uveal reaction after implantation of a plate-haptic silicone intraocular lens (IOL) (C11UB, Chiron) and a hydrophobic acrylic (AcrySof MA60, Alcon) IOL in diabetic patients. SETTING: Moorfields Eye Hospital and St. Thomas' Hospital, London, United Kingdom. METHODS: Thirty-five diabetic patients were recruited consecutively and randomly assigned to have implantation of either of the 2 IOLs. The percentage area of posterior capsule opacification (PCO), anterior capsule contraction (ACC), and postoperative inflammatory indices (flare and cells) were assessed objectively at 2 to 3 weeks, 6 months, and 1 year. Between-group and within-group analyses were conducted using the Student t test or Mann-Whitney test and Friedmann test, respectively. RESULTS: Between-group analysis showed the percentage area of PCO was significantly greater in patients with plate-haptic silicone IOLs at 6 and 12 months (P = .002). At 6 months, ACC was significantly greater in the plate-haptic group (P = .04), but the difference was not significant at 12 months. There was higher flare in the hydrophobic acrylic IOL group than in the plate-haptic silicone IOL group at 2 to 3 weeks (P = .08). Within-group analysis showed that over the follow-up period, the plate-haptic silicone group, but not the hydrophobic acrylic group, had a progressive increase in PCO (P = .003). In the hydrophobic acrylic group, but not the plate-haptic silicone group, there was a significant reduction in the mean anterior chamber flare value (P = .01). There was no significant difference in visual acuity or contrast sensitivity at any postoperative visit. CONCLUSION: In diabetic patients, hydrophobic acrylic IOLs can lead to an increased flare in the early postoperative period but they seem to be more favorable than plate-haptic silicone IOLs because the latter lead to more PCO.

Comparison of posterior capsule opacification rates between hydrophilic and hydrophobic single-piece acrylic intraocular lenses.

PURPOSE: To determine the effect of intraocular lens (IOL) material on the development of posterior capsule opacification (PCO) at 1 year. SETTING: Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: One hundred six eyes of 53 patients with bilateral cataract and no other ocular comorbidity were prospectively randomized to receive a hydrophobic acrylic or hydrophilic acrylic single-piece IOL in the first eye to have surgery. The alternate IOL was implanted in the fellow eye 4 to 6 weeks later. All surgery was performed by a single surgeon. Postoperative follow-up was 1 day, 1 and 6 months, and 1 year. At each visit, the best corrected high- and low-contrast visual acuities were assessed and a high-intensity digital retroillumination photograph was taken. Posterior capsule opacification was assessed from the digital images by a single operator using a dedicated software program and calculated as the percentage area of opacified capsule. RESULTS: One year postoperatively, the median percentage area of PCO was 50.3% in the hydrophilic IOL group and 4.9% in the hydrophobic IOL group (P<.001). The difference in PCO was not accounted for by loss of contact between the capsulorhexis and IOL surface. Further analysis showed that lens epithelial cells tended to invade the posterior capsule at the haptic-optic junction. This was more marked in the hydrophilic IOL group. CONCLUSIONS: The rate of PCO was significantly higher with the hydrophilic IOL. However, the results cannot be attributed to the IOL material alone as they show the importance of both IOL material and design.

Correlation between the measurement of posterior capsule opacification severity and visual function testing.

PURPOSE: To develop software to measure the severity of posterior capsule opacification (PCO) using analysis of retroillumination images and to correlate the results with clinical evaluation of PCO severity and visual function. SETTING: Department of Physics, King's College, and Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: A technique for calculating PCO severity was developed based on calculating the variance of intensity by transforming retroillumination images to a similar mean intensity. The computer-derived severity was compared to grading of clinical severity by 3 independent observers using a library of 100 retroillumination images ranging from clear posterior capsules to very severe PCO. The computer results were also compared with the following other current methods of measuring PCO: Evaluation of Posterior Capsule Opacification (EPCO), POCOman, and Automated Quantification of After-Cataract. A further 35 images were used to compare the results of computer-derived severity with the results of visual function analysis (high-contrast acuity, 100%; low-contrast acuity, 9%) using the Early Treatment Diabetic Retinopathy Study chart, contrast sensitivity testing using the Pelli-Robson chart, and glare assessment using the van den Berg straylight meter. RESULTS: The severity scores showed a good correlation with clinical severity scores for the library of images (r=0.86) and with severity scores using POCOman and EPCO (r=0.85 and r=0.81, respectively). The correlations with visual function tests were also good, with low-contrast visual acuity (9%) showing the best correlation (r=0.87). CONCLUSION: Variance in intensity of PCO was successfully used to calculate the severity of PCO.

Effect of 1-piece and 3-piece AcrySof intraocular lenses on the development of posterior capsule opacification after cataract surgery.

PURPOSE: To evaluate the effect of 1-piece and 3-piece hydrophobic acrylic intraocular lenses (IOLs) on posterior capsule opacification (PCO) after cataract surgery. SETTING: Ophthalmology departments of 3 hospitals in the United Kingdom and Germany and the Department of Physics at a United Kingdom university. METHODS: A series of 131 patients having cataract surgery had implantation of an acrylic 1-piece (SA30AL) or an acrylic 3-piece (MA30BA) IOL (AcrySof, Alcon). Surgery was performed according to standardized protocol by a single surgeon at each hospital. Posterior capsule opacification was assessed using digital retroillumination photography. All images were analyzed at a single center according to a standard protocol. Data were analyzed 6 months and 1 year after surgery. RESULTS: There was no statistically significant difference in the percentage area of PCO between the 1-piece (mean 16.0% +/- 15.7% [SD]) and 3-piece (mean 13.6% +/- 19.8%) cohorts 6 months and 1 year after surgery (P =.0664). CONCLUSION: There was no evidence of a difference in the area of PCO after cataract surgery between 1-piece and 3-piece IOLs, which were otherwise matched for material and lens geometry.

Predicting posterior capsule opacification: value of early retroillumination imaging.

PURPOSE: To investigate the value of early retroillumination imaging of the posterior capsule in predicting the eventual development of posterior capsule opacification (PCO). SETTING: Ophthalmology Department, St. Thomas' Hospital, and Department of Physics, King's College, London, United Kingdom. METHODS: All patients with retroillumination images of the posterior capsule taken 6 months and 2 years after uneventful phacoemulsification with in-the-bag intraocular lens (IOL) implantation were selected. The images were taken using the same hardware and analyzed with the same software to calculate the percentage area of the posterior capsule covered by lens epithelial cells. The percentage area of PCO with all IOL types 6 months postoperatively was correlated with that at 2 years. RESULTS: One hundred forty patients had analyzable images at 6 months and 2 years. Of these, 63 had a poly(methyl methacrylate) (PMMA) IOL (Pharmacia 812A or Storz P497UV), 33 an acrylic (Alcon AcrySof MA30 or SA30), 22 a silicone (Allergan SI-30), and 22 a hydrophilic acrylic (Bausch & Lomb Hydroview H60). The correlation of the percentage area of PCO at 6 months with that at 2 years resulted in an r value of 0.71 (P <.0001) in the entire group. The r value was 0.48 in the PMMA group and 0.86 in the foldable IOL group (P <.0001) (r value: AcrySof, 0.66; silicone, 0.82; Hydroview, 0.75). CONCLUSIONS: Retroillumination imaging of the posterior capsule 6 months after cataract surgery predicted the PCO outcome at 2 years in eyes with foldable IOLs.