Incidence Of Posterior Capsule Opacification Research Articles

Visual outcome and complications of bilateral intraocular lens implantation in children

Purpose To determine the safety and efficacy of bilateral intraocular lens (IOL) implantation in children. Setting Tertiary referral pediatric ophthalmology department. Methods This retrospective study comprised 13 children (26 eyes) who had bilateral cataract surgery with IOL implantation. Patients were divided into 2 groups: congenital cases, diagnosed during the first year of life, and developmental cases, diagnosed after 1 year of age. All patients had small incision phacoemulsification with primary implantation of a poly(methyl methacrylate) or a foldable acrylic IOL. Primary posterior capsulotomy was performed in 16 eyes (61.5%). Results Age at surgery ranged from 1 week to just under 8 years. Seven patients (53.8%) had a systemic diagnosis: Down’s syndrome (n = 4); developmental delay or cerebral atrophy (n = 3). Five children with systemic problems could not cooperate with formal vision testing; 2 could fix and follow bilaterally, and 3 had central, steady, and maintained vision bilaterally. In the congenital group, 37.5% of eyes attained a visual acuity of 20/20 and 87.5%, 20/120 or better. In the developmental group, formal vision testing was possible in 4 children. Five eyes (83.3%) attained a visual acuity of 20/40 or better. Thirteen eyes (50.0%) required posterior capsulotomy. Primary posterior capsulotomy reduced the incidence of posterior capsule opacification (PCO), but there was no correlation between PCO and IOL material. One patient developed glaucoma bilaterally. Conclusion Bilateral IOL implantation was safe and produced good visual results in children of all ages with bilateral cataract.

The Madurai Intraocular Lens Study IV: posterior capsule opacification

PURPOSE: To estimate the cumulative incidence of posterior capsule opacification 4 years after surgery in patients who participated in the Madurai Intraocular Lens Study and had extracapsular cataract extraction with posterior chamber intraocular lens implantation. METHODS: In the Madurai Intraocular Lens Study, 1,700 patients with best-corrected visual acuity 20/120 or worse in the better eye had extracapsular cataract extraction with posterior chamber intraocular lens implantation, and 1,474 (86.7%) of these completed the 1-year follow-up examination. From this group of 1,474 pseudophakic patients, 400 were randomly selected for reexamination 4 years after the original surgery. The eye that was operated on was examined by an ophthalmologist who was involved in the 1-year follow-up examinations and posterior capsule opacification grading. A grading of I to III was used to reflect the degree of opacification. With grades II and III, posterior capsule opacification detectable with an undilated pupil was present in the central axis. RESULTS: Three hundred twenty-seven (81.8%) of the selected population were examined between October 1997 and December 1998. Thirty-four (8.5%) were confirmed as being deceased, and 39 (9.8%) were unavailable for follow-up. The median age was 60 years, and 57.2% were women. The 4-year incidence of grade II or III posterior capsule opacification, including eyes already treated with laser capsulotomy, was 13.1% (95% confidence interval [CI], 9.7% to 17.3%). Each year of increased age was associated with a decreased risk of posterior capsule opacification (odds ratio, 0.96; 95% CI, 0.92 to 1.00). Based on best-corrected visual acuity of 20/40 or worse without co-existing pathology, the 4-year incidence of posterior capsule opacification was 13.5%. CONCLUSION: Because patients with relatively mature cataracts routinely receive extracapsular cataract extraction with posterior chamber intraocular lens implantation instead of the traditional intracapsular extraction, the subsequent need for laser capsulotomy may be less than that anticipated, based on previous reports.

Posterior capsule opacification after phacoemulsification: foldable acrylic versus poly(methyl methacrylate) intraocular lenses

Purpose To study the effects of foldable acrylic and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation on posterior capsule opacification (PCO). Setting Department of Ophthalmology, Dokuz Eylül University School of Medicine, Izmir, Turkey. Methods This consecutive series comprised 157 eyes having phacoemulsification with implantation of a foldable acrylic IOL with rectangular optic edges and a 5.5 mm optic (AcrySof®) (n = 80 eyes) or a PMMA IOL with rounded optic edges and 5.5 mm optic (n = 77). Evaluated were incidence, location, and degree of PCO. Mean postoperative follow-up was 17.8 months ± 1.7 (SD) (range 16 to 22 months). Results Posterior capsule opacification occurred in 8.7% of eyes in the foldable acrylic IOL group and in 24.7% of eyes in the PMMA IOL group. The difference between the 2 groups was statistically significant ( P < .01). Centrally located PCO was significantly lower in the acrylic group ( P < .01). There were 3 eyes with severe PCO in the PMMA group and none in the acrylic group. Anterior capsule contraction and fibrosis were present in 4 eyes in the PMMA group but none in the acrylic group. Soemmering’s ring cataract formation was detected in 3 eyes, all with the AcrySof IOL. Conclusion In addition to its optic material and rectangular optic edges, the AcrySof IOL provides additional advantages in lowering the incidence of PCO compared with rounded-edge PMMA IOLs.

Surgical prevention of posterior capsule opacification: Part 1: progress in eliminating this complication of cataract surgery

PurposeTo evaluate over almost 2 decades the success of a component of cataract surgery that represents a critical step in reducing the incidence of posterior capsule opacification (PCO); namely, the efficacy of cortical cleanup. SettingCenter for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. MethodsAccessioned from the early 1980s to 1997, 3320 eyes obtained postmortem with posterior chamber intraocular lenses were analyzed with respect to formation of a postoperative Soemmering’s ring. This anatomic lesion, the precursor of clinical PCO, represents an important and measurable indication of the quality of cortical cleanup. Its formation was documented using Miyake–Apple posterior photographic analysis. ResultsThe quality and thoroughness of cortical cleanup and overall effectiveness in eliminating retained and/or regenerating cortical cells, as measured by scoring of Soemmering’s rings, showed virtually no net change since the early 1980s. The intensity of Soemmering’s ring was higher in the most recent specimens than in those in the early 1980s. ConclusionThe results indicate that renewed attention to cortical cleanup in cataract surgery is warranted for significant reduction in incidence or the elimination of PCO. More attention to the hydrodissection (cortical cleaving hydrodissection) step of the procedure is likely a practical, immediately implementable, and inexpensive remedy.

Surgical prevention of posterior capsule opacification: Part 2: enhancement of cortical cleanup by focusing on hydrodissection

PurposeTo experimentally analyze the role and efficacy of hydrodissection in achieving maximal cortical cleanup. SettingCenter for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. MethodsPhacoemulsification and irrigation/aspiration were performed in 10 pairs of human eyes (20 eyes) obtained postmortem. Ten eyes had previous hydrodissection and 10 eyes, no hydrodissection. The time (seconds) required for complete lens substance removal in each procedure was measured. In addition, a qualitative evaluation of difficulty of surgery was noted. ResultsPhacoemulsification required 28.6% less time in eyes with previous hydrodissection than in those without. Irrigation/aspiration time was reduced by 50.9% when hydrodissection was performed. The total time of each procedure required for complete evacuation of the capsular bag was reduced by an average of 37.7% in eyes with hydrodissection. Furthermore, qualitatively the procedure was far easier, less stressful, and caused less posterior capsule stress or rupture when copious hydrodissection was performed. ConclusionsHydrodissection enhances the general safety and efficiency of cortical cleanup, especially at 12 o’clock. Hydrodissection is the best available, practical, immediately implementable, and inexpensive means to help remove equatorial E-cells and thus alleviate the incidence of posterior capsule opacification.

Effect of intraocular lens and anterior capsule opening type on posterior capsule opacification

Purpose To determine the effect of intraocular lens (IOL) type and anterior capsulectomy technique on the incidence of posterior capsule opacification. Setting Department of Ophthalmology, Medical Faculty, University of Ondokuz Mayis, Samsun, Turkey. Methods Three hundred two eyes of 294 patients were examined retrospectively after IOL implantation in the capsular bag performed between February 1991 and November 1996. Patients were divided into 3 groups according to IOL type: poly(methyl methacrylate) (PMMA); heparin-surface-modified PMMA (HSM PMMA); plate-haptic silicone. Envelope capsulectomy or continuous curvilinear capsulorhexis (CCC) was used. Mean follow-up was 27 months (range 12 to 33 months). Results Posterior capsule opacification developed in 47 cases (15.6%): 21.7% in the PMMA lens group after planned extracapsular cataract extraction (ECCE), 17.4% in the HSM PMMA lens group after planned ECCE, and 7.7% in the plate-haptic silicone lens group after phacoemulsification. Posterior capsule opacification occurred less in patients who had anterior capsulectomy using the CCC technique (11.5%) than in those having an envelope capsulectomy (24.5%) ( P < .05). Posterior capsule opacification was significantly less in eyes with a capsular-bag-fixated plate-haptic silicone lens than in those with a PMMA or HSM PMMA IOL ( P < .05). Conclusion This study demonstrated that the anterior capsulectomy technique and the IOL type influence the incidence of PCO.

Retinal complications after cataract extraction in patients with high myopia

Objective To assess risk factors and incidence of retinal complications after cataract extraction in patients with high myopia. Design Retrospective, noncomparative case series. Participants One hundred eighteen patients with highly myopic eyes who had an axial length of 26 mm or more (mean axial length, 30.13 ± 2.08 mm) and who underwent cataract surgery over a period of 6 years were studied. Intervention Patients underwent cataract extraction either by extracapsular cataract extraction (ECCE) or phacoemulsification. Prophylactic argon laser photocoagulation was performed in 13 eyes for retinal tears recognized before surgery and in 13 eyes after surgery; neodymium:YAG (Nd:YAG) laser capsulotomy was performed for patients with posterior capsule opacification (PCO) that affected the vision. Main outcome measures Incidence of retinal detachment and PCO and percentage of prophylactic argon laser or of Nd:YAG laser treatments. Results Of the 118 eyes, 73 (61.9%) underwent ECCE and 45 (38.1%) underwent phacoemulsification. Posterior capsule opacification was the most common complication and was found in 30 eyes (25.4%). Thirteen patients (11%) received prophylactic laser treatment for retinal tears before cataract operation, and 13 more patients (11%) had postoperative retinal tears requiring laser treatments. None of these patients developed retinal detachment. Two patients (1.69%) developed retinal detachment within 6 months after their operations. There were no intraoperative complications, and postoperative Nd:YAG capsulotomy was not performed in these two patients. Conclusions Active searching and prophylactic laser treatments for retinal tears developed before and after cataract extraction in patients with high myopia are recommended. This may lower the incidence of postoperative retinal detachment.

Posterior capsule opacification 5 yearsafter extracapsular cataract extraction

Purpose: To find out whether there is a “hidden” group of patients with posteriorcapsule opacification (PCO) 5 years after cataract surgery and to establish the incidence of PCO. Setting: Department of Ophthalmology, Sahlgrenska University Hospital, Gothenburg, Sweden. Methods: A random sample (n = 164) was selected among patients who had extracapsular cataract extraction (ECCE) with intraocular lens implantation in 1991 (N = 1672). All surgically treated cases that required neodymium:YAG (Nd:YAG) laser capsulotomy (n = 37) within the first 5 years after surgery were recorded. Patients still alive 5 years after surgery who had not had Nd:YAG treatment were offered an eye examination to determine whether PCO requiring capsulotomy existed. Results: Thirty-seven of 110 patients (34%) alive 5 years after surgery had had an Nd:YAG capsulotomy during the first 5 postoperative years. Follow-up was possible in 51 of 73 untreated patients (70%). Clinically significant PCO according to specified criteria was found in 7 cases (14%). Half of them would benefit from treatment, the other half had visual impairment from other eye disease. Conclusions: The estimated incidence of PCO 5 years after ECCE was 43%. Five years after 'surgery, there was an untreated group with clinically significant PCO, approximately 9% of the surgically, treated population. This hidden group must be considered in PCO studies.

Posterior capsule opacification and neodymium:YAG capsulotomy with heparin-surface-modified intraocular lenses

Purpose: To compare the effect of heparin-surface-modified (HSM) and conventional unmodified poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) on the formation of posterior capsule opacification (PCO).Setting: Department of Ophthalmology, Vejle Hospital, Denmark.Methods: This prospective, randomized, double-blind study comprised 250 eyes of 246 patients who had uneventful extracapsular cataract extraction in otherwise healthy eyes with implantation of a biconvex IOL or a convex-piano lens with a continuous laser ridge. Patients were examined once a year for 3 years, at which time the degree of PCO was recorded. A neodymium:YAG laser capsulotomy was performed if certain criteria were met.Results: The incidence of PCO was statistically significantly higher in eyes with an HSM convex-piano laser-ridge IOL than in those with an unmodified convex-piano lens (P < .005). There were no significant differences between any other groups.Conclusion: The incidence of PCO was higher in eyes with an HSM convex-piano IOL with a laser ridge.

Inhibition of Migrating Lens Epithelial Cells at the Capsular Bend Created by the Rectangular Optic Edge of a Posterior Chamber Intraocular Lens

To study the mechanism of the reportedly low incidence of posterior capsule opacification (PCO) in eyes treated with a posterior chamber intraocular lens (PC IOL). Various IOL designs, including the PC IOL, were studied using scanning electron microscopy. Rabbit lens capsules were studied histopathologically 2, 3, and 4 weeks after implantation of a PC IOL in one eye and a biconvex polymethylmethacrylate (PMMA) IOL in the contralateral eye as a control. The optic edge of the PC IOL was sharp and rectangular, whereas that of the biconvex PMMA or silicone IOLs from various manufacturers had been smoothed and rounded by polishing. PCO was significantly reduced in the eye with a PC IOL in all rabbits. The lens capsule wrapped tightly around the optic edge of the PC IOL so that it conformed to the same shape and thereby created a distinct rectangular bend in the capsule or a rectangle between the optic edge and the posterior capsule. Migrating lens epithelial cells (LECs) were obviously inhibited at that site. A discontinuous capsular bend or rectangle created by the sharp, square optic edge of the PC IOL may have induced contact inhibition to migrating LECs and reduced PCO. How, whether, and to what extent this design-dependent effect is influenced by features of the IOL material needs to be clarified by comparison with results achieved with an IOL made from the same material in a different design and vice versa.

A systematic overview of the incidence of posterior capsule opacification

Objective Reported rates of posterior capsule opacification (PCO) vary widely and are based on various definitions of PCO, varying lengths and intervals of follow-up, and the use of different surgical techniques, intraocular lens (IOL) designs, and methods of IOL implantation. This study was designed to obtain a more precise overall estimate of the incidence of PCO and to explore factors that might influence the rate of PCO development. Design A meta-analysis. Methods Published articles were selected for study based on a computerized MEDLINE search of the literature and a manual search of the bibliographies of relevant articles. Articles meeting selected inclusion criteria were reviewed systematically, and the reported data were abstracted and synthesized using the statistical techniques of meta-analysis. Main outcome measure Pooled estimates of the proportion of eyes developing PCO at three postoperative timepoints—1 year, 3 years, and 5 years—were measured. Results There is significant heterogeneity among published rates of PCO. The overall pooled estimates (95% confidence limits) of the incidence of PCO were 11.8% (9.3%–14.3%) at 1 year, 20.7% (16.6%–24.9%) at 3 years, and 28.4% (18.4%–38.4%) at 5 years after surgery. There is no evidence of a significant decline in PCO incidence during the study period. Conclusions Visually significant PCO develops in more than 25% of patients undergoing standard extracapsular cataract extraction or phacoemulsification with posterior chamber intraocular lens implantation over the first 5 years after surgery. Patient characteristics, surgical techniques, and differences in research design and reporting may account for some of the variability in reported rates. However, no specific factors were identified in the authors’ analysis. More precise estimates of incidence and identification of risk factors for PCO will depend on the development of a standardized measurement of PCO and wider adoption of more rigorous study methodology.

The Inhibition of Lens Epithelial Cell Migration by a Discontinuous Capsular Bend Created by a Band-Shaped Circular Loop or a Capsule-Bending Ring

This study investigated the inhibitory effect of a discontinuous capsular bend created by an intraocular lens (IOL) with a band-shaped loop or a capsule tension ring on migrating lens epithelial cells (LECs). To create a sharp bend in the capsule, the round form (shown on cross section) of the open-circular loop of a polymethylmethacrylate IOL was changed to a band-like shape, 1.0 mm wide and 0.2 mm thick. A capsule tension ring of the same shape (on cross section) with a 14-mm diameter was also made. After cataract surgery, this IOL or ring was implanted into the capsular bag in 5 rabbit eyes. The same IOL with an unmodified haptic or conventional capsule tension ring was implanted in the contralateral eye as a control. After 8 weeks, Miyake view and histopathologic examinations were performed. LECs accumulated at the equatorial corner outside the haptic or ring, showing the inhibition of LEC migration. In the control eyes, LECs accumulated inside the haptic or ring, forming a Soemmering's ring cataract, thus showing markedly less inhibition of LEC migration on macroscopic and microscopic observations. A discontinuous bend in the capsule significantly inhibited LEC migration in rabbit eyes. The creation of a capsular bend through the appropriate design of the IOL-haptic or capsule tension ring might significantly decrease the incidence of posterior capsule opacification for humans.

Posterior Capsulectomy in Pediatric Cataract Surgery: The Necessity of a Choice

The purpose of the study is to evaluate whether a posterior capsulectomy combined with anterior vitrectomy is a necessity in pediatric cataract. The incidence of posterior capsule opacification, the need for additional surgical interventions, and the influence of a primary posterior capsulectomy after cataract surgery in children were evaluated. The analysis was carried out by studying patients' records retrospectively or after prospective follow-up. In 94 eyes (69 aphakic and 25 pseudophakic), the medical records were studied retrospectively. Twenty-eight eyes (18 aphakic and 10 pseudophakic) were observed prospectively during 1 year after surgery. In 20 eyes (6 aphakic and 14 pseudophakic) of 10 patients with bilateral cataract, a prospective comparison between the 2 eyes of the same patient also was carried out. Cataract surgery through the limbus with or without a primary posterior capsulectomy was performed in 114 eyes (43 of these received a posterior chamber intraocular lens [IOL] and 71 remained aphakic). In 28 eyes, the surgery was carried out by way of the pars plana (6 eyes received an anterior chamber IOL and 22 remained aphakic). Incidence of posterior capsule opacification, the need for secondary surgical intervention, and visual acuity were measured. Opacification of the posterior capsule is observed in all children's eyes when a primary posterior capsulectomy (combined with an anterior vitrectomy) was not carried out. Earlier secondary cataract formation is associated with a younger age and with implantation of an IOL. Eyes undergoing a primary opening of the posterior capsule during the initial surgery of children with bilateral cataract achieved, in most cases, a better visual acuity than did their fellow eyes. Although possibly a choice in older children, a primary posterior capsulectomy combined with anterior vitrectomy is a must in younger children and particularly when implantation of an IOL is planned.

Increased cataract rate and characteristics of Nd:YAG laser capsulotomy in retinitis pigmentosa

Retinitis pigmentosa (RP) is associated with the development of a posterior subcapsular cataract (PSC). The development of posterior capsule opacification (PCO) after cataract surgery and a decrease of central visual acuity is sometimes misinterpreted by the patients as natural course of RP. Therefore, therapeutic intervention is often delayed. In a retrospective study (part 1) the incidence of PCO was evaluated in a group of 26 RP patients who underwent cataract surgery and IOL implantation. In a prospective analyse (part 2) PCO was quantified in 13 RP patients using the standardized photographic technique and image analysis system introduced by Tetz et al. Matched pairs were formed with a control group of 13 patients without retinal disease who matched the RP group in terms of age distribution and postoperative follow-up time. In part 3 the parameters of Nd:YAG laser capsulotomy in 12 RP patients and 14 controls were evaluated. Part 1: The cumulative PCO rate in RP at the end of the first postoperative year was 14.6%, 26.8% in the second, 53.7% in the third and 70.7% after the third year. Nd:YAG laser capsulotomy was performed in 70% of eyes (after 18.4 +/- 14.7 months). In eyes with significant PCO development 70% had PSC preoperatively, while in eyes without PCO formation only 41.7% showed PSC. Part 2: The matched pairs analysis showed a significantly higher PCO value for RP patients (2.11 +/- 1.42) than for the control group (0.89 +/- 0.72) (P = 0.038). Part 3: Average Nd:YAG laser energy levels were 12.8 +/- 11.2 MJ (RP) and 7.6 +/- 6.7 MJ (control). Some 25% of RP patients required further laser treatment of regrown secondary cataract. Patients with RP showed a significantly higher incidence and density of PCO. Whether RP-specific pathomechanisms are responsible for this needs further investigation.

Posterior Capsule Opacification after Cataract Surgery in Patients with Uveitis

To compare the incidence rate of posterior capsule opacification (PCO) after phacoemulsification and standard extracapsular cataract extraction (P/ECCE) in eyes with antecedent uveitis with the incidence rate in eyes without any history of intraocular inflammation. Review of records of 108 eyes of 78 patients with uveitis and 122 eyes of 106 patients with no uveitis who underwent P/ECCE. Rates of PCO were compared by the log-rank test of differences in the Kaplan-Meier survival curves. Proportional hazards regression models provided estimates of the relative risks of PCO among uveitic compared to nonuveitic eyes. Performance of neodymium: YAG laser posterior capsulotomy was used as a proxy measure for the main outcome of visually significant PCO. Study patients ranged in age from 6 to 81 years (median, 44.5 years) among those with uveitis and 27 to 96 years (median, 68.5 years) among those without uveitis (P = 0.0001). Crude incidence rates for visually significant PCO were 54% over a mean follow-up of 4.3 years in uveitic cases and 40% over a mean follow-up of 3.9 years among nonuveitic cases (P = 0.02). Estimates of PCO incidence (95% confidence interval) in uveitic eyes derived from the Kaplan-Meier models were 38.5% (range, 28.9%-48.2%) at 1 year and 56% (range, 45.8%-66.3%) at 3 years, and estimates among nonuveitic eyes were 11.5% (range, 6.2%-16.8%) at 1 year and 38.4% (range, 29%-47.8%) at 3 years. These rates of PCO among patients with uveitis and those patients without uveitis differed significantly by the log-rank test (P = 0.004). However, after adjusting for the younger age of patients with uveitis, the rates of PCO were no longer statistically different. The apparent higher rate of PCO in patients with uveitis is primarily due to their younger age at the time of surgery. A moderately increased independent risk of PCO from uveitis cannot, however, be ruled out by this study.

Posterior Capsulorhexis with Optic Capture in Pediatric Cataract and Intraocular Lens Surgery

A major concern in pediatric intraocular lens implantation surgery is the high incidence of posterior capsule opacification. The purpose of this article is to investigate a surgical technique for maintaining a clear visual axis after pediatric cataract and intraocular lens surgery. In a prospective evaluation, posterior capsulorhexis with optic capture as a surgical technique for preventing secondary membrane formation after pediatric cataract extraction is investigated. This technique involves capture of an intraocular lens optic through a posterior curvilinear capsulorhexis opening. Perioperative complications and incidence of secondary cataract are presented. Results will be compared to an historic cohort of patients with pediatric cataract-intraocular lens who did not have posterior continuous curvilinear capsulorhexis with optic capture. In 13 consecutive eyes operated on in children aged 2 to 12 years (mean, 5.8 years), there was no opacification of the visual axis at a mean follow-up of 19 months after surgery (range, 8-30 years). Posterior capsulorhexis with optic capture holds promise as a technique for preventing secondary membrane formation. This maneuver ensures centration of the posterior chamber intraocular lens while eliminating the need for an anterior vitrectomy. Apposition of the anterior and posterior capsule leaflets anterior to the optic may limit the migration of Elschnig pearls, reducing the incidence of secondary membranes and the need for additional procedures.

Posterior capsule opacification and capsulotomy rates with taco-style hydrogel intraocular lenses

Purpose: To evaluate posterior capsule opacification (PCO) formation and neodymium:YAG (Nd:YAG) laser capsulotomy results in eyes with an logel intraocular lens (IOL).Setting: First University Hospital, Vienna, Austria.Methods: A retrospective study was done of 108 eyes with one of three types of an logel IOL that had decreased vision from PCO and required posterior capsule discission.Results: In general, in eyes with sulcus-placed IOLs, a Soemmering's ring formed and the capsulorhexis rim tightly adhered to the posterior capsule, sealing the capsular bag periphery. Elschnig pearls had broken the barrier, invading the retrolental space. In eyes with bag-placed IOLs, there was a gap between the IOL and posterior capsule in which Elschnig pearls had accumulated. This gap frequently extended beneath the flanges to the periphery of the capsular bag, allowing residual lens epithelial cells to proliferate and migrate centrally.Conclusion: The logel lenses led to a high incidence of regeneratory PCO within the gap between the lens and capsule that might be the result of the properties of the lens' hydrogel material rather than its design.

Neodymium:YAG capsulotomy rates after phacoemulsification with silicone posterior chamber intraocular lenses

Purpose: To retrospectively evaluate the incidence of neodymium:YAG (Nd:YAG) laser capsulotomies for posterior capsule opacification (PCO) in eyes receiving one of two types of capsular-bag-fixated silicone posterior chamber intraocular lenses (IOLs) over 7 years.Setting: John Moran Eye Center, University of Utah, Salt Lake City.Methods: Four hundred eighty-eight eyes that had cataract extraction with a continuous curvilinear capsulorhexis and implantation of one of two kinds of silicone posterior chamber IOLs were evaluated to assess the incidence of PCO. One hundred thirty-nine received a one-piece, plate-type IOL (Staar) and 349, a three-piece, modified C-loop IOL (AMO).Results: With an average follow-up of 84.3 weeks in the Staar IOL group and 93.5 weeks in the AMO IOL group, the incidence of posterior Nd:YAG laser capsulotomy for PCO was 30.2% and 39.1 %, respectively.Conclusion: The incidence of Nd:YAG laser capsulotomy after phacoemulsification with implantation of a silicone posterior chamber IOL was still relatively high with long-term follow-up. Although the proportion of patients with a one-piece silicone IOL requiring Nd:YAG capsulotomy was less than that in the three-piece silicone IOL group, the difference was not statistically significant.

Capsulorhexis size and posterior capsule opacification

Purpose: Posterior capsule opacification (PCO) after intraocular lens (IOL) implantation has a multifactored pathogenesis. Capsulorhexis and capsular bag implantation of a one-piece, biconvex poly(methyl methacrylate) (PMMA) IOL are likely to reduce the PCO incidence. This study was performed to determine whether an ideal capsulorhexis size able to reduce PCO incidence exists.Methods: A retrospective study of 107 patients who had extracapsular cataract extraction with capsulorhexis and capsular bag IOL implantation was carried out. The PCO site (central, paracentral, and peripheral) and degree (mild, moderate, and severe) were evaluated in relation to the capsulorhexis edge location relative to the IOL optic. Slitlamp biomicroscopy and photography and examination with a threemirror Goldmann lens were performed. Patients were divided into three groups. Group 1: capsulorhexis free edge located on the IOL optic for 360 degrees; Group 2: capsulorhexis free edge located asymmetrically on and peripherally to the IOL optic; Group 3: capsulorhexis free edge located peripherally to IOL optic for 360 degrees. Each group was divided into two subgroups; one received polyHema IOLs and the second, PMMA IOLs.Results: In Groups 1 and 2, the capsular transparency was higher than in Group 3 (P < .04). Central opacification percentage was lower in Group 1 than in Groups 2 and 3 (P < .04). No statistically significant differences between the polyHema and the PMMA subgroups were seen.Conclusions: Capsulorhexis with a slightly smaller diameter than the IOL optic appears to be better than a large-size capsulorhexis in reducing the incidence of PCO.

Extracapsular Cataract Extraction with or without Posterior Chamber Intraocular Lenses in Eyes with Cataract and High Myopia

To compare the results of insertion of low-power or zero-power posterior chamber intraocular lenses (PC IOLs) after cataract extraction in eyes with high myopia with leaving the eye aphakic. The outcome of extracapsular cataract extraction (ECCE) with low-power or zero-power PC IOLs in 184 consecutive highly myopic (axial length = 26.0 mm or longer) eyes was compared with 184 consecutive highly myopic eyes receiving ECCE without PC IOLs. Axial length, preoperative visual acuity, age, sex, and follow-up were similar between both groups. In the pseudophakic eyes, there was a statistically significantly better visual outcome (P = 0.006), decreased incidence of posterior capsule opacification (13.6% versus 33.2%, P < 0.01), and decreased requirement for YAG capsulotomy (6.5% versus 17.9%, P < 0.01). There were two retinal detachments in the pseudophakic eyes compared with four in the aphakic eyes. There were no sight-threatening complications in 12 pseudophakic eyes after YAG capsulotomy. There were four sight-threatening complications (2 retinal detachments, 2 cases of uveitis with secondary glaucoma) in 33 aphakic eyes after YAG capsulotomy. The use of PC IOLs may result in a lower complication rate and better visual outcome after ECCE in eyes with cataract and high myopia.