Optic Edge Design Research Articles

Contributed Session I: Negative dysphotopsia evaluation using individualized eye models

Building on our previously communicated results, the current study evaluates the predictive ability of individualized eye models to localize negative dysphotopsia (ND) in the peripheral field of view (PFoV) In a prospective study conducted at Hanusch Hospital, Vienna, Austria, post-operative biometrical data were acquired from five patients implanted with monofocal IOLs and with ND complaints. A Harms tangent screen subjective method was used to localize in PFoV the perceived shadow (HvF). For computing theoretical retinal irradiance maps, individualized Liou-Brennan (non)-sequential eye models were generated using the acquired biometrical data. Mean axial length was 22.83 (21.05 - 24.80) mm, mean IOL power 24.4 (20.5 - 30.0) D, mean IOL tilt -1.86 (-6.21 - 2.96) degrees and mean decentration 0.16 (-0.27 - 0.44) mm. Average residual astigmatism difference between theoretical and measured data was 0.49 (0.02 - 0.97) D. Aligned with HvF data, the irradiance maps localized ND in the peripheral visual field up to 85 degrees. Previously presented theoretical results evidenced that in identical biometrical conditions, IOLs from different manufacturers with similar mechanical platforms but different optic edge designs are characterized by comparable ND profiles with the peripheral location of the shadows between 69 and 76 degrees. Further expanding the utilization of these eye models, the current results demonstrate their clinical relevance in terms of PFoV localization of ND.

Intraocular lens optic edge design for the prevention of posterior capsule opacification after cataract surgery.

Intraocular lens optic edge design for the prevention of posterior capsule opacification after cataract surgery.

A COMPARISION OF POSTERIOR CAPSULAR OPACITY FORMATION UPTO 1 YEAR IN PATIENTS WITH SMALL INCISION CATARACT SURGERY WITH FOLDABLE INTRAOCULAR LENS AND PHACOEMULSIFICATION WITH THE SAME INTRAOCULAR LENS

Introduction: Cataract is most common cause of curable blindness worldwide and cataract surgery is most common procedure performed in ophthalmology. Posterior capsular opacification (PCO) is most common complication after cataract surgery which is usually treated with Neodymium-doped: Yttrium Garnet (Nd:YAG) laser posterior capsulotomy or occasionally with a surgical capsulotomy. The incidence and severity of PCO correlates to the type of surgical technique, IOL optic edge designs and IOL materials. Material and Methods: 70 eyes of 64 patients operated for age related cataract were studied in this prospective interventional study. Phacoemulsification was done in 35 eyes and SICS in 35 eyes with hydrophobic single piece biconvex foldable intraocular lens. Patients were followed up at 1, 3, 6, 9 and 12 months for the development of PCO. Clinically significant PCO (loss of 2 or more lines of Snellen’s visual acuity chart) was treated with Nd:YAG laser capsulotomy. Results: The overall incidence of PCO was 22.85%. Amongst the patients who developed PCO, SICS and phacoemulsification was performed in 62.5% and 37.5% patients respectively. Result was statistically significant with p value <0.05 using z test. On first postoperative day, patients operated with phacoemulsification had better visual acuity than SICS. Conclusion: Phacoemulsification can provide early and better visual outcome than SICS and has lower incidence of PCO formation which may be due to difference in irrigation and aspiration and less disruption of blood aqueous barrier than SICS. PCO can be reduced by atraumatic surgery and thorough cortical clean up and capsular polishing.

Effect of AcrySof versus other intraocular lens properties on the risk of Nd:YAG capsulotomy after cataract surgery: A systematic literature review and network meta-analysis.

ObjectiveThe purpose of this study was to evaluate the impact of different intraocular lens materials (IOL) and optic edge designs on the incidence of Nd:YAG laser capsulotomy.MethodsRandomized controlled trials (RCTs) reporting incidence of Nd:YAG capsulotomy in patients with monofocal IOLs were identified for systematic literature review (SLR) using Cochrane methodology. A network meta-analysis was conducted under a Bayesian framework. Mean hazard ratios (HRs), 95% credible intervals, and one-sided p-values were estimated for Nd:YAG capsulotomy incidence by comparing AcrySof IOLs with a group of non-AcrySof hydrophobic acrylic, hydrophilic acrylic, silicone, and PMMA IOLs. Sensitivity analysis was conducted comparing the risk of Nd:YAG capsulotomy between sharp- and round-edged designs of the above IOLs.ResultsAcrySof IOLs had a lower risk of Nd:YAG capsulotomy compared to hydrophobic acrylic (HR: 2.68; 95% CrI: 1.41, 4.77; p < 0.01), hydrophilic acrylic (HR: 7.54; 95% CrI: 4.24, 14.06; p < 0.001), PMMA (HR: 3.64, 95% CrI: 1.87, 6.33; p < 0.001), and silicone (HR: 1.13; 95% CrI: 0.59, 1.91; p <0.1) IOLs. The risk for Nd:YAG was highest among sharp-edged IOLs for hydrophilic acrylic IOLs (HR: 9.32; 95% CrI: 4.32, 19.29; p < 0.01), followed by other hydrophobic acrylic (HR: 2.91; 95% CrI: 1.27, 5.88; p < 0.01), silicone (HR: 0.838; 95% CrI: 0.328, 1.74; p = 0.69), and PMMA (HR: 0.39; 95% CrI: 0.042, 1.49; p = 0.93) IOLs, compared to AcrySof. Acrysof IOLs had a lower risk of Nd:YAG compared to PMMA (HR: 3.25; 95% CrI: 1.21, 7.37; p < 0.01) and silicone, round edge IOLs (HR: 3.84; 95% CrI: 1.08, 10.64; p = 0.015).ConclusionThe risk of Nd:YAG capsulotomy is lower in eyes implanted with AcrySof IOLs compared to non-AcrySof hydrophobic or hydrophilic acrylic IOLs. Sharp-edged AcrySof, PMMA, and silicone IOLs are comparable in terms of reducing the risk of Nd:YAG laser capsulotomy.

Incidence and associated factors of posterior capsule opacification formation in pseudophakic patients at Cipto Mangunkusumo Hospital : January - December 2010

&#x0D; &#x0D; &#x0D; Objective: Posterior capsule opacification (PCO) is the most common postoperative consequence of cataract surgery which may cause visual acuity reduction. The incidence of PCO in Indonesia has not been reported yet. The objectives of this study were to evaluate three years cumulative incidence of PCO and factors associated with PCO formation at Cipto Mangunkusumo (CM) Hospital. &#x0D; Methods: This was a retrospective descriptive study to patients with uneventful senile cataract surgery in year of 2010. All related data were retrieved from those medical records in year of 2013, which included patient demographics, type of surgery, time of PCO stated, IOL characteristics (material, optic edge design and diametere. Best corrected visual acuity (BCVA) pre operatively, when PCO was determined and Nd:YAG laser (Neodymium- doped yttrium aluminium garnet) was performed in decimal. &#x0D; Result: A total of 578 eyes (485 patients) was involved in this study. Three years cumulative incidence of the PCO was 8.82% (51 eyes). Phacoemulsification surgery was conducted in 496 (85.8%) eyes. The median time to PCO was being determined was 21 months (range 1 to 34 months) with the mean of BCVA was 0.50±0.26. Age, gender, and type of surgery had no related factors to PCO, but higher evidence in using of hydrophilic acrylic IOL (10.7%) was found. After laser Nd:YAG laser was performed, BCVA was improved. &#x0D; Conclusion: Three years cumulative incidence of PCO was 8.82% and there was no defined related factor to PCO reformation, but eye had been using hydrophilic acrylic IOL seem to be higher percentage &#x0D; &#x0D; &#x0D;

Intraocular lens optic edge design for the prevention of posterior capsule opacification after cataract surgery

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: The aim of this review is to summarise the effects of modifications in intraocular lens optic edge design on PCO after cataract surgery.

Incidence and associated factors of posterior capsule opacification in pseudophakic patients at Cipto Mangunkusumo Hospital

Background: Posterior capsule opacification (PCO) is the most common postoperative consequence of cataract surgery which may cause visual acuity reduction, yet the incidence in Indonesia has not been reported. The objectives of this study were to evaluate three years cumulative incidence of PCO and factors associated with PCO formation at Cipto Mangunkusumo Hospital, Jakarta.Methods: This was a retrospective descriptive study on patients with uneventful senile cataract surgery during year 2010. All related data were retrieved from medical records in year 2013, which included patient demographics, type of surgery, intraocular lens (IOL) characteristics (material, optic edge design and diameter). Moreover, time to first PCO diagnosis (month), and best corrected visual acuity (BCVA) pre-operatively, at time PCO was diagnosed and two weeks after Neodymium-doped yttrium aluminum garnet (Nd:YAG) laser were noted (decimal).Results: A total of 578 eyes (485 patients) were involved in this study. Three years cumulative incidence of the PCO was 8.82% (51 eyes). Phacoemulsification surgery was performed in 496 (85.8%) eyes. The median time to PCO diagnosis was 21 months (range 1 to 34 months), mean of BCVA was 0.50 ± 0.26. Age (&lt;65 and &gt;65 years old) was not associated to PCO. Higher incidence of PCO was found in patients using hydrophilic acrylic IOL (10.7%) than in hydrophobic acrylic (6.2%). After Nd:YAG laser was performed, BCVA was improved to 1.00.Conclusion: Three years cumulative incidence of PCO was 8.82% and there was no defined factor related to PCO formation, but higher percentage of PCO occured in patients using hydrophilic acrylic IOL than in hydrophobic acrylic.

Posterior capsule opacification after lens implantation: incidence, risk factors and management

Postoperative capsular opacification is a multifactorial physiological consequence of cataract surgery. Opacification involving the central posterior capsule has a significant impact on high- and low-contrast acuity and low-contrast sensitivity. The proliferation, migration and abnormal differentiation of residual lens epithelial cells and fibers in the capsular bag have been implicated in the pathogenesis of posterior capsule opacification (PCO). The incidence and severity of PCO correlates to the use of surgical techniques, intraocular lens optic edge designs and intraocular lens materials. This article summarizes the clinical studies with recommendations for retarding the development of central PCO. These studies will remain critical for future endeavors undertaken for the eradication of PCO.

Effect of intraocular lens design on posterior capsule opacification

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. Many studies have attempted to identify factors that influence the development of PCO. The aim of this systematic review based on Cochrane methodology was to summarize the effects of intraocular lens (IOL) geometry, including modifications of the IOL optic (especially optic edge design) and haptics, on the development of PCO. Twenty-six prospective randomized controlled trials with a follow-up of at least 12 months were included. In 5 of 7 studies, visual acuity was better in sharp-edged IOLs than in round-edged IOL. The PCO score was significantly lower with sharp-edged IOLs but did not differ significantly between 1-piece and 3-piece open-loop IOLs. Because of the significant difference in the PCO score, sharp-edged IOL optics should be preferred to round-edged IOL optics.

Fellow-eye comparison of posterior capsule opacification with AcrySof SN60AT and AF-1 YA-60BB blue-blocking intraocular lenses

To evaluate intraindividual differences in posterior capsule opacification (PCO) and visual performance of AcrySof SN60AT (Alcon Laboratories) and AF-1 YA-60BB (Hoya Corp.) intraocular lenses (IOLs). Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom. In this prospective single-surgeon standardized-surgical-procedure fellow-eye comparison, an AcrySof SN60AT or an AF-1 YA-60BB IOL was randomized to the first eye of 36 patients and fellow-eye surgery was performed within 4 to 6 weeks. Follow-up was at 1, 3, 6, 12, and 24 months. Best distance- corrected logMAR visual acuity was measured at 100% and 9% contrast. Contrast sensitivity was measured using the Functional Acuity Contrast Test (FACT) on the Optec 3500 instrument (Stereo Optical Company, Inc.). Color vision was assessed with the Farnsworth Munsell 100-hue test. After pupil dilation, digital retroillumination photographs were taken and the percentage area of PCO was calculated using POCO software. Posterior capsule opacification was significantly greater in the AF-1 YA-60BB group than in the AcrySof SN60AT group at all time points (P<.0001), with the difference greatest at 24 months. At 24 months, 100% contrast visual acuity was significantly better in the AcrySof SN60AT group than in the AF-1 YA-60BB group (P = .0313); 9% contrast visual acuity was significantly better in the AcrySof SN60AT group from 6 months onward. There was no significant difference between groups in color vision or contrast sensitivity. Electron microscopy showed the AcrySof SN60AT IOL has a much sharper posterior edge profile. The AcrySof SN60AT IOL had better PCO performance and thus visual performance than the AF-1 YA-60BB IOL. This is attributable to the differences in optic edge design.

Optic Edge Design as Long-term Factor for Posterior Capsular Opacification Rates

To compare the difference in posterior capsular opacification (PCO) between highly refractive silicone and hydrophobic acrylic foldable intraocular lenses (IOLs) with sharp and round edge designs 3 years after in-the-bag IOL implantation in subjects undergoing bilateral cataract surgery. Open-label, prospective, randomized, multicenter clinical trial. Two hundred and eighty-eight patients with bilateral surgery for senile cataract operated in German university clinics, eye hospitals, and private ophthalmic surgical centers (Aachen, Ahaus, Bad Hersfeld, Frankfurt/Main, Jena, Rosenheim, and Sulzbach/Saar). At each center, a highly refractive index silicone IOL with a sharp optic edge (CeeOn) was intraindividually compared either with a high-refractive index silicone IOL with a round optic edge (PhacoFlex) in 108 patients or with an acrylic IOL with a sharp optic edge (AcrySof) in 139 patients. All patients received standard phacoemulsification with IOL implantation in the bag in both eyes from the same surgeon. A morphological evaluation of PCO was performed by the Evaluation of the Posterior Capsule Opacification (EPCO) system 1 to 2 weeks and 11 to 14 and 35 to 37 months after surgery. The blinded digital pictures were evaluated by an independent investigator. Posterior capsular opacification was statistically evaluated by paired comparisons of 3-year cumulative incidences of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser treatment and EPCO scores. Posterior capsular opacification. The 3-year cumulative incidences of Nd:YAG laser capsulotomy were 2.1% (CeeOn), compared with 2.1% (AcrySof) (risk difference, 0%; 90% confidence interval, -3.4% to 3.4%), and 5.7% (CeeOn), compared with 17.0% (PhacoFlex) (risk difference, -11.4%; 90% confidence interval, -18.1% to -4.7%). In patients without Nd:YAG laser treatment, medians of the total area EPCO score were 0.0005 (CeeOn) versus 0.0440 (AcrySof) and 0 (CeeOn) versus 0.0700 (PhacoFlex) at 3 years. Functional results, safety, and handling did not significantly differ for the 3 lenses. Our results suggest that modern foldable IOLs have a low incidence of PCO after 3 years. There is less PCO for sharp optic edge designs independent of IOL material.

Post-operative Capsular Opacification: A review

Post-operative capsular opacification is a multifactorial physiological consequence of cataract surgery. Opacification involving the central posterior capsule has a significant impact on high and low contrast acuity and low contrast sensitivity. The assessment of Posterior Capsule Opacification (PCO) on cadaver eyes, experimental studies, culture models and in clinical studies has provided an understanding of its pathogenesis. The proliferation, migration and abnormal differentiation of residual lens epithelial cells and fibers in the capsular bag have been implicated in the pathogenesis of PCO. The incidence and severity of PCO correlates to the meticulous use of surgical techniques, IOL optic edge designs and IOL materials. This article summarizes the clinical studies with recommendations for retarding the development of central PCO. It discusses experiments with pharmacological agents broadly categorized as anti-inflammatory, immuno-modulating, antiproliferative, antiadhering, antitransdifferentiating agents for the prevention of PCO. These studies will remain critical for future endeavors undertaken for eradication of PCO.

Influence of 360-degree enhanced optic edge design of a hydrophilic acrylic intraocular lens on posterior capsule opacification

To compare the rate of posterior capsule opacification (PCO) with the single-piece hydrophilic acrylic foldable Rayner Centerflex 570H intraocular lens (IOL), which has a sharp optic edge design excluding the optic-haptic junction, and the Rayner C-flex 570C IOL, which has an improved 360-degree sharp edge. Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. As part of a multicenter U.S. Food and Drug Administration (FDA) study, 42 patients who had implantation of a C-flex IOL in 1 eye after uneventful phacoemulsification were enrolled. Six and 12 months postoperatively, PCO was evaluated by retroillumination photographs using Evaluation of Posterior Capsule Opacification (EPCO) 2000 image-analysis software. The data were then compared with those in a matched group of patients with a Centerflex IOL who participated in a previous FDA study. The mean age of the patients with the C-flex IOL was 71.5 years +/- 8.2 (SD) There was a statistically significant difference in EPCO scores between the C-flex group and Centerflex group. Six months after surgery, the mean EPCO value (total IOL optic) was 0.07 +/- 0.17 in the C-flex group (n = 37) and 0.20 +/- 0.20 in the Centerflex group (n = 36) (P<.01, Wilcoxon test). By 12 months, the mean had increased to 0.16 +/- 0.20 in the C-flex group (n = 37) and 0.35 +/- 0.22 in the Centerflex group (n = 31) (P<.01, Wilcoxon test). The C-flex IOLs showed good functional results and significantly lower PCO formation than the earlier model Centerflex IOL. The enhanced edge of the C-flex IOL seemed to improve PCO prevention clinically.

Quantitative Analysis of Posterior Capsule Opacification of Hydrophobic Acrylic Intraocular Lenses

Posterior capsule opacification (PCO) remains a common complication of modern cataract surgery, although both modification of materials used and changes in the intraocular lens (IOL) optic edge design have helped to decrease its incidence slightly. Recently, various kinds of quantitative methods have been developed for measuring PCO. The purpose of this study was to compare the quantitative analysis of PCO between different types of IOL designs. Patients enrolled in the study had age-related cataract and underwent uneventful cataract surgery and implantation of either the AcrySof MA30BA (Alcon) or the Sensor AR40e (AMO), which are differently designed hydrophobic acrylic IOLs with a sharp-edged optic design. Postoperative examination was performed at 6 months. Retroillumination photographs of each eye were obtained, and the degree of PCO was assessed using the Evaluation of Posterior Capsule Opacification (EPCO) system. Grade 1 PCO was noted in both the MA30BA and the AR40e groups. There was no significant difference in the mean PCO score between the MA30BA and AR40e groups. Although the sharp-edged optic designs of both IOLs might similarly inhibit PCO at 6 months, a long-term follow-up period is needed to determine if any PCO differences occur between these 2 hydrophobic acrylic IOLs.

Efficacy of Different Intraocular Lens Materials and Optic Edge Designs in Preventing Posterior Capsular Opacification: A Meta-Analysis

To evaluate the efficacy of different intraocular lens (IOL) materials and optic edge designs in preventing posterior capsular opacification (PCO). Systematic review and meta-analysis. Pertinent studies were selected through an electronic search of the Cochrane Library, MEDLINE, and Embase. The randomized controlled trials meeting the predefined criteria were reviewed systematically by meta-analysis. The treatment effects were measured as risk difference, and the pooled estimates were computed according to a random effect model. In total, 23 randomized controlled trials were included in the present meta-analysis. The pooled risk differences of Nd:YAG laser capsulotomy rates were -24% (95% confidence interval [CI], -29% to -20%) comparing acrylic with polymethylmethacrylate (PMMA) lenses; -9% (95% CI, -17% to -1%) comparing silicone with PMMA lenses; 14% (95% CI, -8% to 36%) comparing hydrogel with PMMA lenses; 4% (95% CI, -2% to 10%) comparing silicone with acrylic lenses; 19% (95% CI, 8% to 30%) comparing hydrogel with acrylic lenses; and 28% (95% CI, 10% to 46%) comparing hydrogel with silicone lenses. The pooled risk differences of PCO rates were -39% (95% CI, -47% to -31%) comparing acrylic with PMMA lenses; -14% (95% CI, -29% to 0%) comparing silicone with acrylic lenses; 56% (95% CI, 36% to 75%) comparing hydrogel with acrylic lenses; and 48% (95% CI, 31% to 64%) comparing hydrogel with silicone lenses. When comparing sharp with rounded-edge designs, pooled risk differences of capsulotomy rates were -47% (95% CI, -77% to -17%) in PMMA lenses, -22% (95% CI, -47% to 2%) in acrylic lenses, and -9% (95% CI, -17% to 0%) in silicone lenses; pooled risk differences of PCO rates were -28% (95% CI, -50% to -7%) in acrylic lenses and -37% (95% CI, -46% to -27%) in silicone lenses. The rates of PCO and Nd:YAG laser capsulotomy may be influenced by different IOL biomaterials and optic edge designs. The lenses made by acrylic and silicone and those with sharp optic edges are superior in lowering the rates of PCO and laser capsulotomy.

Influences of optic edge design on posterior capsule opacification and anterior capsule contraction

To investigate the influence of optic edge design on posterior capsule opacification (PCO) and anterior capsule contraction (ACC). A total of 43 eyes of 43 patients scheduled to undergo cataract surgery were included in this study. Patients received either a Sensor AR40 intraocular lens (IOL) or a Sensor AR40e IOL. The area of the anterior capsule opening (ACO) was determined by diaphanoscopy using the anterior eye segment analysis system EAS-1000 at 1 day, 1 week and 1, 3, 6 and 12 months postoperatively. Posterior capsule opacification was evaluated objectively in two ways, using either the EAS-1000 or POCOman. There was no significant difference between the two groups in either ACO area or percentage reduction of ACO area at any time-point after surgery. The difference in the degree of PCO 1 year after surgery was not significant when measured by either the EAS-1000 or POCOman. A sharp IOL edge is required to prevent PCO. Sharp-edged IOLs do not appear to be a risk factor for ACC.

Routine posterior optic buttonholing for eradication of posterior capsule opacification in adults

To study the efficacy of posterior optic buttonholing (POBH) through a primary posterior capsulorhexis (PPCCC) to preserve full capsular transparency, and its potential as a routine alternative to standard in-the-bag implantation of sharp-edged optic intraocular lenses (IOLs). Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. After standard cataract removal, a PPCCC 4.0 to 5.0 mm in diameter was performed and the optic of a 3-piece IOL buttonholed posteriorly. One third of the eyes additionally had extensive anterior capsule polishing. All surgeries were performed under topical anesthesia. The first 500 consecutive surgeries were evaluated. In 11 eyes, POBH was not performed as planned. In 4 cases, anterior capsulorhexis fixation of the optic was used as an alternative. In the early series, vitreous entanglement was seen in 5 eyes, of which 1 case prompted translimbal anterior vitrectomy. No case of cystoid macula edema was observed. One case of peripheral retinal detachment in a highly-myopic eye 4 months postoperatively appeared to be unrelated to the surgery. All lenses were well-centered without tilt, and both capsule leaves remained clear especially after additional polishing. Posterior optic buttonholing precludes lens epithelial cells from accessing the retrolental space. The sandwiched posterior capsule blocks optic contact and thus fibrosis of the anterior capsule. Posterior optic buttonholing avoids after-cataract independent of optic edge design. Anterior capsule polishing adds to its efficacy by excluding any residual fibrosis. Surgery under topical anesthesia was well-controlled and safe. Posterior optic buttonholing may become a routine alternative to standard in-the-bag IOL implantation when supported by a longer follow-up.

Quantitative Nachstarevaluierung von Acrylat- und Silikonintraokularlinsen mit scharfem Kantendesign

At the Department of Ophthalmology, Heidelberg, Germany, posterior capsule opacification (PCO) of a silicone and an acrylic intraocular lens (IOL) with a sharp optic edge design was evaluated. In a prospective study either the AMO ClariFlex silicone IOL or the Sensar AR40e hydrophobic acrylic IOL were implanted in 47 patients following uneventful phacoemulsification. Mean patient age was 76.2+/-7.8 (ClariFlex) and 73.4+/-12.9 years (AR40e), respectively. The mean follow-up time was 19.7+/-5.34 in the ClariFlex and 21.9+/-1.89 months in the AR40e group. PCO development was evaluated postoperatively using the EPCO 2000 analysis software (scale 0-4). Areas of interest were the total IOL optic, the central 3-mm zone as well as the capsulorhexis. In both groups, all patients achieved a BCVA of 20/32 (AR40e) and 20/25 (ClariFlex), respectively. There was a very low incidence of PCO development with a mean EPCO score of 0.07+/-0.2 (ClariFlex and 0.15+/-0.2 (AR40e). Within the 3-mm zone and the capsulorhexis, there was a tendency for even lower EPCO scores in both groups. We calculated a statistically significant difference for the two lens materials for all investigated IOL areas (Wilcoxon's test, p<0.05). Both IOLs with a sharp edge design showed good functional results, a stable position in the capsular bag as well as a low incidence of PCO development. However, the silicone IOL showed statistically significantly lower PCO scores.

Evaluating and defining the sharpness of intraocular lenses

To develop a new method for the evaluation of the optic edge design of intraocular lenses (IOLs). Charité Humboldt University and Berlin Eye Research Institute (Beri), Berlin, Germany. Poly(methyl methacrylate) IOLs with 11 edge designs were manufactured. Each lens design was evaluated using EPCO 2000. Also, edge's ability to stop cell growth was observed by placing each IOL into cell culture and observing cell growth over 18 days on average. Only 3 groups, those with the sharpest edge design, prevented the growth of lens epithelial cells onto the visual axis of the lens. The edge design that effectively stopped cell growth was characterized by an area above the edge of 13.5 microm2 at the most. Results shows that the edge design of IOLs plays an important role in the prevention of posterior capsule opacification. A specific optic edge design was most effective in this prevention.

Influence of optic edge design, optic material, and haptic design on capsular bend configuration

To assess and classify capsular bend configuration at the optic rim and its association with posterior capsule (PCO) and anterior capsule opacification (ACO) and capsulorhexis contraction with various intraocular lenses (IOLs). Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. A total of 659 post-cataract surgery eyes of 370 patients from different prospective randomized studies were evaluated. All eyes had standardized phacoemulsification surgery with implantation of an IOL in the capsular bag. The IOLs had a sharp or round optic edge design and were made of silicone, acrylic, or poly(methyl methacrylate) optic materials. One year postoperatively, the configuration of the capsular bend at the optic rim was assessed at the slitlamp, and standardized slitlamp images of ACO and fibrotic PCO were taken. One week, 1 year, and 3 years postoperatively, digital retroillumination images were taken for objective quantification of regeneratory PCO and the capsulorhexis area. The outcome measures were the type of capsular bend configuration, ACO score (0% to 100%), regeneratory PCO score (0 to 10), fibrotic PCO score (0 to 3), and amount of capsulorhexis contraction (mm(2)). Four main types of capsular bend configuration were classified: parallel, "Y," right angle, and wrapping. The right-angle type was observed in the most cases (52%). Eyes with a wrapping capsular bend configuration had significantly less PCO, more capsulorhexis contraction, and more ACO than eyes with the other configurations. Wrapping capsule configuration was seen most often (55%) in round-edged silicone IOLs that had a thin optic rim. The design and material of IOLs influenced the long-term capsular bend configuration at the optic rim. The right-angle type was the most common capsular bend configuration. Intraocular lenses with silicone optic material and a thin optic rim caused a wrapping capsule configuration and resulted in more capsulorhexis contraction and ACO, but less PCO.