Secondary surgical and neodymium-YAG laser discissions

Outcome of Surgical Membranectomy With a Vitrector via Limbal Approach for Posterior Capsular Opacity in Children

PURPOSE

To evaluate the safety and efficacy of surgical membranectomy with a vitrector via a limbal approach for posterior capsular opacification (PCO) in children.

METHODS

In this retrospective analytical interventional study, medical records of children younger than 17 years who underwent surgical membranectomy with anterior vitrectomy via a limbal approach were analyzed. Time lag for PCO formation after cataract surgery was assessed. Any adverse events during surgery, rate of successful completion of membranectomy, postoperative complications, improvement in visual acuity, and intraocular lens (IOL) centration were recorded.

RESULTS

A total of 60 eyes of 58 children were included: 26 had traumatic etiology and 34 had developmental cataract. Mean time duration for PCO formation was 27.83 ± 39.83 months for traumatic cases and 53.53 ± 52.20 months for developmental cataract (P = .04). A satisfactory opening in the center of the membrane was achieved in 47 cases (n = 47, 78.3%). The complications encountered were uveitis (5 eyes), corneal edema (3 eyes), pigment deposition over IOL (2 eyes), raised intraocular pressure (1 eye), IOL drop (1 eye), and broken haptic (1 eye). Membranectomy with posterior optic buttonholing of the IOL in 9 aphakic eyes resulted in good IOL centration, no anterior chamber reaction, and no iris optic capture in the postoperative period. Mean visual acuity improved from 1.16 ± 0.52 to 0.73 ± 0.55 logMAR (P < .001).

CONCLUSIONS

Surgical membranectomy with a vitrector via a limbal approach is a safe and effective method for managing PCO in the pediatric population. Posterior optic buttonholing of the IOL during membranectomy or secondary IOL implantation results in good IOL centration and fewer complications. [J Pediatr Ophthalmol Strabismus. 2020;57(1):33-38.].

[OCT measurement of the impact of Nd:YAG laser capsulotomy on foveal thickness]

INTRODUCTION

Posterior capsular opacification is the commonest complication of cataract surgery. It is treated with Nd:YAG laser capsulotomy. However, after treatment, cases of cystoid macular edema have been reported. The purpose of this study was to measure the foveal thickness change after Nd:YAG capsulotomy using optical coherence tomography (OCT) in order to clarify the physiopathology of this edema.

PATIENTS AND METHODS

A prospective, single-center study was conducted on patients who underwent Nd:YAG laser capsulotomy between May 2008 and November 2009. All patients received the same drug protocol after Nd:YAG capsulotomy (acetazolamide, apraclonidine, and rimexolone). Demographic parameters (age, sex, and medical history), clinical features (visual acuity, intraocular pressure) before and after Nd:YAG laser, and laser complications were analyzed. Central foveal thickness was measured by OCT (Stratus OCT 3, Zeiss). Data were collected before Nd:YAG laser capsulotomy and 1 week, 1 month, and 3 months after capsulotomy. The preoperative and postoperative thicknesses were compared. We used a Student t-test for statistical analysis.

RESULTS

Thirty eyes of 26 patients were analyzed. The mean foveal thickness was 209 ± 26 μm before capsulotomy, 213 ± 23 μm, 204 ± 19 μm, 213 ± 23 μm 1 week, 1 month, and 3 months, respectively, after capsulotomy. The foveal thickness did not significantly change during the first 3 months following laser treatment. No complications occurred.

DISCUSSION AND CONCLUSION

Macular cystoid edema was a classical complication after Nd:YAG capsulotomy. However, there was no significant increase of macular thickness shortly after Nd:YAG capsulotomy in our study.

Cost of cataract surgery after implantation of three intraocular lenses

Background:

Posterior capsule opacification is one of the most frequent adverse events following cataract surgery. This manuscript reports the lifetime cost of complications linked to posterior capsule opacification using three types of intraocular lens with square edges.

Methods:

Costs were estimated from a retrospective study of patients who underwent cataract surgery and data from the literature. The lenses studied were hydrophobic acrylic (SA60AT and AR40E) and hydrophilic acrylic (XL-Stabi) lenses with square edges. The frequency of Nd-Yag laser capsulotomies after 4 years’ survival was estimated by two methods: the first involved linear adjustment of the rate at 5 and 6 years follow-up and then application of a constant rate after 6 years; the second involved linear adjustment after 5 years follow-up. The economic perspective was that of the French Sickness Fund.

Results:

After 3 years’ follow-up the percentage of patients who had not undergone laser Nd-Yag capsulotomy was 86.9% with SA60AT, 76.6% with AR40E and 54.6% with XL-Stabi lenses (p < 0.001). The total cost of capsulotomy and management of complications per patient lifetime was estimated to be €90.5 for SA60AT, €189.5 for AR40E and €288.0 for XL-Stabi lenses by the first extrapolation method. With the second method of extrapolation the costs were €94.8, €200.0 and €300.2, respectively.

Interpretation:

Lower costs for cataract surgery and management of related complications were observed with the two hydrophobic acrylic lenses; the lowest costs were observed with SA60AT lenses as they were associated with fewer Nd-Yag laser capsulotomies.

Neodymium:YAG laser posterior capsulotomy after implantation of AcrySof intraocular lenses

PURPOSE

To report the incidence of neodymium:YAG (Nd:YAG) laser posterior capsulotomy after phacoemulsification and implantation of AcrySof (Alcon) intraocular lenses (IOLs).

SETTING

Private practice, Wolfe Clinic, Marshalltown, Iowa, USA.

METHODS

A retrospective diagnosis and procedure code review of 12419 consecutive cases having phacoemulsification and AcrySof IOL implantation from January 1995 through December 2002 was performed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies.

RESULTS

An Nd:YAG laser posterior capsulotomy was performed in 763 (6.1%) of the 12419 cases. The incidence of posterior capsulotomy was approximately 1% at 1 year, increasing in linear fashion by approximately 1% to 2% per year.

CONCLUSIONS

The Nd:YAG laser posterior capsulotomy rate after implantation of AcrySof IOLs was relatively low; the cumulative rate was approximately 1% to 2% new cases per year over a 7-year period, with a plateau suggested at year 6.

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.

Use of Nd:YAG laser capsulotomy

Surgery for cataract removal has become successively refined such that posterior capsular opacification is the most common problem presenting after modern cataract extraction. Various techniques and treatments exist to manage patients with posterior capsular opacification using Nd:YAG capsulotomy. There are many possible variations in initial assessment, pre-laser treatments, laser techniques, and follow-up routines. The literature on the use of Nd:YAG laser for capsulotomy was reviewed and interpreted. This article presents the currently available knowledge in a format that allows the practitioner to tailor an evidence-based protocol for treating patients with symptomatic posterior capsule opacification.

Pseudophakic retinal detachment

Pseudophakic retinal detachment is a rare, but potentially serious, complication of cataract surgery. The incidence of pseudophakic retinal detachment following current surgical techniques of cataract extraction, including extracapsular cataract extraction by nuclear expression and phacoemulsification, is lower than that found after intracapsular cataract extraction. The risk of pseudophakic retinal detachment appears to be increased in myopic patients, in those patients in whom vitreous loss had occurred at the time of cataract surgery, and in patients undergoing Nd:YAG posterior capsulotomy. Most cases present to the clinician when the macula is already detached and the central vision is affected. When evaluating patients with pseudophakic retinal detachment, the fundal view is often impaired by anterior or posterior capsular opacification, reflections related to the intraocular lens, or poor mydriasis. Scleral buckling, pneumatic retinopexy, and primary pars plana vitrectomy, with or without combined scleral buckling, are the surgical techniques used to treat pseudophakic retinal detachment. Anatomical success rates are high after vitreo-retinal surgery for pseudophakic retinal detachment, although a smaller proportion of patients recover good vision following surgery.

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.

Cystoid macular edema in the era of ocular hypotensive lipids

PURPOSE

To review cystoid macular edema in relationship with ocular hypotensive lipids and to present recommendations for use in eyes at increased risk of cystoid macular edema.

DESIGN

Focused literature review and authors' clinical experience.

METHODS

Cystoid macular edema in association with cataract surgery, epinephrine therapy, and ocular hypotensive lipid therapy is reviewed.

RESULTS

Cystoid macular edema may be associated with a variety of therapeutic interventions, predominantly in eyes at increased risk with open or absent posterior lens capsule and ocular inflammation. Based primarily on experience with latanoprost, the association between ocular hypotensive lipids and cystoid macular edema, even in high-risk eyes, although present, appears to be low.

CONCLUSIONS

Considering the low incidence of cystoid macular edema associated with latanoprost therapy, the authors feel that after maximal tolerable medical therapy and with proper precautions, the use of an ocular hypotensive lipid is an acceptable alternative to filtration surgery in high-risk eyes.

Posterior capsule opacification and lens epithelial cell layer formation: Hydroview hydrogel versus AcrySof acrylic intraocular lenses

PURPOSE

To quantitatively compare the incidence of visually significant posterior capsule opacification (PCO) and lens epithelial cell (LEC) layer formation on the anterior surface of Hydroview hydrogel and AcrySof acrylic foldable intraocular lenses (IOLs) after implantation.

SETTING

Single-surgeon ophthalmology practice, Orange Base Hospital, and Dudley Private Hospital, Orange, New South Wales, Australia.

METHODS

This retrospective study comprised 166 eyes of 150 patients (after exclusions) who had cataract extraction and insertion of a foldable IOL in the capsular bag by a single surgeon using a standardized phacoemulsification technique from December 1997 to September 1998. The mean follow-up was 13.1 months (range 6.0 to 23.6 months). The eyes were divided into 2 groups based on the type of IOL implanted: Storz Hydroview H60M (81 eyes) or Alcon AcrySof MA30BA (85 eyes). A neodymium:YAG posterior capsule laser capsulotomy (PC YAG) was performed for an objective decrease in Snellen best corrected visual acuity (BCVA) of more than 1 line, significant visual symptoms, or both. This was used as a measure of visually significant PCO. An Nd:YAG anterior surface clearance (ASC YAG) was done for LEC layer formation anterior to the IOL to better visualize or facilitate treatment of PCO. The rates of PC YAG and ASC YAG after Hydroview and AcrySof IOL implantation were statistically compared.

RESULTS

Forty-five eyes (55.6%) in the Hydroview IOL group and 3 eyes (3.5%) in the AcrySof IOL group required a PC YAG; the risk difference was 52.0% (P <.001). An ASC YAG was required in 27 eyes (33.3%) in the Hydroview group and 1 eye (1.2%) in the AcrySof group; the risk difference was 32.2% (P <.001). Survival analysis demonstrated that the only independent predictor of the incidence of PC YAG and ASC YAG over time was IOL type, with the Hydroview IOL group having a statistically significantly higher incidence of both procedures.

CONCLUSION

There was a greater incidence of visually significant PCO and LEC layer formation on the anterior surface of Hydroview IOLs than of AcrySof IOLs.

Clinical assessment of long-term safety and efficacy of a widely implanted polyacrylic intraocular lens material

PURPOSE

To evaluate the long-term safety and efficacy, in a large series of patients, of polyacrylic intraocular lens implants 1 and 3 years after surgery, compared with polymethylmethacrylate intraocular lens implants.

METHODS

This was a randomized, prospective study of 1,514 eyes of 1,202 patients that were examined for a 1-year follow-up study and 1,264 eyes of 990 patients that were examined for a 3-year follow-up study. All the patients were prospectively randomized to receive a polyacrylic or polymethylmethacrylate intraocular lens implant. A standardized surgical protocol was performed using a phacoemulsification technique and capsulorhexis. Any surgical complications were excluded, and all patients had standard postoperative medication and follow-up. Postoperative measurements included spectacle-corrected visual acuity, occurrence of postoperative sight-threatening or lens-related complications, and adverse reactions. Results were compared between the polyacrylic intraocular lens and polymethylmethacrylate intraocular lens groups. Results were also compared with standards for polymethylmethacrylate intraocular lens that were established by the US Food and Drug Administration and a previous study for silicone lens.

RESULTS

The overall complete follow-up rates were 79.9% for 1-year follow-up and 69.5% for 3-year follow-up. At 1 year, the mean logarithm of the minimum angle of resolution (logMAR) of visual acuity was 0.037 +/- 0.150 and 0.042 +/- 0.154 in best case patients of the polyacrylic intraocular lens group and polymethylmethacrylate intraocular lens group, respectively. At 3 years, the mean logMAR visual acuity was 0.038 +/- 0.155 and 0.054 +/- 0.181 in best case patients in the polyacrylic intraocular lens group and polymethylmethacrylate intraocular lens group. There was no significant difference between groups at 1 and 3 years. At 1 year, 96.8% of best case patients in the polyacrylic intraocular lens group and 95.8% of those in the polymethylmethacrylate intraocular lens group achieved corrected visual acuity of 0.5 or better. At 3 years, 96.4% of best case patients in the polyacrylic intraocular lens group and 94.9% of those in the polymethylmethacrylate group achieved a corrected visual acuity of 0.5 or better; no significant difference was found at 1 and 3 years. The rate of sight-threatening complications was 1. 2% for the polyacrylic intraocular lens group of all patients and 1. 5% for the polymethylmethacrylate intraocular lens group at 1 year, and 1.6% for the polyacrylic intraocular lens group and 1.4% for the polymethylmethacrylate intraocular lens group at 3 years. No significant difference was found between the groups. The cumulative rate of Nd:YAG capsulotomy for the polyacrylic intraocular lens group (7.1%) was significantly lower than that for the polymethylmethacrylate intraocular lens group (38.1%) through 3 years (P <.0001).

CONCLUSIONS

Polyacrylic intraocular lenses demonstrated safe and effective performance through long-term follow-up at a level equal to or better than polymethylmethacrylate intraocular lenses. Patients undergoing polyacrylic intraocular lens implantation achieved excellent postoperative visual acuity and experienced a low rate of postoperative complications, adverse reactions, and Nd:YAG capsulotomy. These long-term clinical results are an important outcome database for the ongoing use of this foldable optic material.

Retinal breaks before and after neodymium:YAG posterior capsulotomy

PURPOSE

To determine the frequency of asymptomatic retinal breaks before and after neodymium:YAG (Nd:YAG) laser posterior capsulotomy.

SETTING

Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.

METHODS

Of 350 consecutive patients referred for their first laser Nd:YAG posterior capsulotomy, 235 eligible eyes were enrolled and 220 eyes completed the study. A vitreoretinal surgeon looked for retinal breaks using binocular indirect ophthalmoscopy with scleral indentation. The eyes were examined 1 week before and 1 hour and 1 month after the posterior capsulotomy. The number, type, and location of retinal breaks were recorded.

RESULTS

The median age of eligible patients who did not participate in the study was higher than that of enrolled patients (79.6 versus 74.4 years; P =.0005). The mean axial length, median time from cataract surgery, and the course of cataract surgery were comparable in both groups. Before the posterior capsulotomy, an untreated retinal break was diagnosed in 4 of the 235 eyes (1.7%; 95% confidence interval [CI] 0 to 4) scheduled for surgery and an undiagnosed retinal detachment was present in 2 additional eyes (0.9%; 95% CI 0 to 3). An asymptomatic retinal break was also present in 4 fellow eyes (1.7%, 95% CI 0 to 4). No new breaks developed during Nd:YAG posterior capsulotomy using a median total energy of 51 mJ (range 10 to 901 mJ) and a median number of 22 applications (range 4 to 341 applications) and resulting in an opening with a median largest diameter of 3.4 mm (range 2.0 to 4.6 mm). In 1 treated eye (0.4%; 95% CI 0 to 2), a new retinal break had developed by 1 month postoperatively.

CONCLUSIONS

The observed 2.1% frequency of asymptomatic retinal breaks that had escaped the attention of the referring ophthalmologist or had developed by 1 month after Nd:YAG posterior capsulotomy can be contrasted with the 0.5% to 2.0% frequency of retinal detachment reported in the literature. However, it is not known which proportion of such asymptomatic breaks, if any, will progress to detachment after Nd:YAG laser posterior capsulotomy.

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.

Posterior capsule opacification 5 years after extracapsular cataract extraction

PURPOSE

To find out whether there is a "hidden" group of patients with posterior capsule 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 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.

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 (i.o.l.) 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.

Posterior capsule opacification after cataract surgery in patients with uveitis

PURPOSE

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.

DESIGN

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.

MAIN OUTCOME MEASURES

Performance of neodymium: YAG laser posterior capsulotomy was used as a proxy measure for the main outcome of visually significant PCO.

RESULTS

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.

CONCLUSIONS

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.

Clinical assessment of long-term safety and efficacy of a widely implanted silicone intraocular lens material

PURPOSE

To summarize the long-term safety and efficacy, in a large series of patients, of intraocular lenses made from a second-generation silicone material (AMO SLM-2/UV) widely used as an intraocular lens material.

METHODS

This was a prospective study of adult patients who received posterior-chamber intraocular lenses with an optic composed of a high-index-of-refraction, ultraviolet-light-absorbing silicone (AMO SLM-2/UV). In 501 patients, clinical data through 3 years postoperative are presented. Postoperative measurements included spectacle-corrected visual acuity, occurrence of postoperative sight-threatening or lens-related complications, and adverse reactions. Results were compared with the standards established by the US Food and Drug Administration (FDA) for polymethylmethacrylate lenses.

RESULTS

At 1 year, 95.2% (496/521) of all patients in group I achieved corrected visual acuity of 20/40 or better. This compared well with the standard reported for polymethylmethacrylate lenses (88%, 2,521/2,864). At 3 years, 94.3% (347/368) of best-case patients achieved corrected visual acuity of 20/40 or better. The rate of sight-threatening complications reported at the final postoperative examination at 3 years was 2.0% (10/501). The rate of Nd:YAG capsulotomy was 27.5% (138/501) through 3 years.

CONCLUSION

Lenses made of the SLM-2/UV silicone material demonstrated safe and effective performance through long-term follow-up at a level equal to or better than established standards for polymethylmethacrylate lenses.

After-cataract formation in newborn rabbits implanted with intraocular lenses

PURPOSE

Comparison of the after-cataract formation in newborn rabbits implanted with a heparin-surface-modified (HSM) intraocular lens (IOL), a silicone IOL, or no IOL.

METHODS

Two groups of 3-week-old rabbits were used. In Group 1 (n = 11), lensectomy was performed in both eyes. One eye was selected at random and an HSM IOL was implanted in the capsular bag; the other eye was left aphakic. In Group 2 (n = 13), lensectomy was performed in both eyes. An HSM IOL was implanted in one eye, a silicone IOL in the other. The wet mass of the dissected after-cataract was determined 3 months after surgery in both groups.

RESULTS

In Group 1, the wet mass of the dissected after-cataract was 17.0 +/- 6.5 mg (mean +/- SEM) in eyes implanted with an HSM IOL and 159.7 +/- 17.0 mg in aphakic eyes. This difference was statistically significant (P < .01). In Group 2, the wet mass of the dissected after-cataract was 18.3 +/- 4.3 mg in eyes implanted with an HSM IOL and 25.7 +/- 5.2 mg in eyes implanted with a silicone IOL. No statistically significant difference was found.

CONCLUSIONS

In young rabbits, implantation of an IOL in the capsular bag following lensectomy reduced cell proliferation.

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.

Long-term clinical results of AMO PhacoFlex model SI-18 intraocular lens implantation

The AMO PhacoFlex Model SI-18 was the first commercially available three-piece silicone intraocular lens (IOL) for use in small incision cataract surgery. Allergan Medical Optics' silicone IOLs have been implanted in more than 750,000 patients worldwide over the past eight years. This report of the FDA clinical investigation of the AMO PhacoFlex model SI-18 IOL summarizes one year follow-up data from the initial premarket approval clinical trial on 500 core patients implanted with the SI-18 lens. One-year follow-up data from 5,860 patients in the modified core group and three-year follow-up data on the 500 patient core/modified core group are also presented. At three years postoperatively, 91.3% of best case core/modified core patients achieved 20/40 or better corrected visual acuity. Overall incidence of persistent complications at three years was 3.2%.

Inhibition of cell adhesion to lens capsule by LCM 1910, an RGD-derived peptide

Opacification of the posterior lens capsule, (secondary cataract), is one of the major complications of extracapsular cataract extraction. The lens epithelial cells remaining after surgery migrate and proliferate along posterior capsule, and give rise to structures such as pearls and cells with contractile properties, which considerably hamper vision. One pharmacological approach aimed at limiting this phenomenon would be to stop this cell migration, thus inhibiting their proliferation. It has been shown that cells adhere and migrate on their support via adhesion molecules such as integrins. Generally, the tripeptide sequence Arg-Gly-Asp (RGD) is the recognition motif for these receptors. In this study, cell adhesion inhibition in the presence of RGD peptides and derivatives was measured on extracellular matrix and lens capsule. One of these compounds, the [N alpha-acetyl-NG(H+)-arginyl]-glycyl-[C beta (H)-C alpha -benzyl]-aspartamid- HCl] (LCM 1910), significantly inhibited cell migration at millimolar concentrations, and could be of interest in prevention of secondary cataract.

Early central posterior capsular fibrosis in sulcus-fixated biconvex intraocular lenses

A series of 228 eyes implanted with one-piece all poly(methyl methacrylate) (PMMA) biconvex posterior chamber intraocular lenses was examined for posterior capsule opacification. One hundred forty-one eyes (61.8%) had opacification at an average postoperative period of 19.7 months. Seventy eyes (30.7%) developed an unusual form of early central posterior capsular fibrosis (ECPCF), which was confined to the capsulorhexis opening, sparing the peripheral aspect of the anterior and posterior capsules. Risk factors for developing this form of opacification were close apposition of peripheral anterior and posterior capsules caused by placing a posteriorly vaulted biconvex optic anterior to a capsulorhexis opening smaller than the optic diameter. This opacification occurred most often in cases of haptic fixation in the ciliary sulcus. The cumulative capsulotomy rate in this series was 5.26% at three months, 9.1% at 12 months, and 13.2% at 20 months. Of the ECPCF cases, 34.3% eventually required neodymium: YAG (Nd:YAG) laser capsulotomy; the capsulotomy rate for ECPCF was 4.8 times higher than that for Elschnig pearls. Early onset of ECPCF (average onset = 19.4 weeks) resulted in early Nd:YAG capsulotomy (average = 8.0 months after surgery). One-piece all-PMMA biconvex intraocular lenses may promote early central fibrosis of the posterior capsule if the lens optic is anterior to a capsulorhexis opening smaller than the optic diameter. The early onset of this form of opacification predisposes to earlier Nd:YAG capsulotomy with a higher risk of complications.

Risk factors for posterior capsular pearling after uncomplicated extracapsular cataract extraction and plano-convex posterior chamber lens implantation

We retrospectively reviewed 542 consecutive cases of extracapsular cataract extraction with implantation of a plano-convex laser ridge posterior chamber intraocular lens. We were interested in the incidence and probability of the development of postcapsular epithelial pearling that required laser capsulotomy and the risk factors associated with it. After four years of follow-up, 21% of all cases had developed pearling. Over the same period, the probability of pearling, as determined by the Kaplan-Meier curves, was 29% with a 95% confidence interval between 22% and 36%. After one year of follow-up, the probability of pearling was 5%; after two years, 15%; after three years, 24%. Younger age (50 years or less), larger optic, and smaller IOL were identified as significant risk factors when each of these factors was analyzed separately. When all risk factors were studied together, and after applying confounding statistics, only younger age was identified as a significant risk factor (P = .003).

Aqueous humor analysis after Nd:YAG laser capsulotomy with the laser flare-cell meter

Using the laser flare-cell meter (Kowa FC-1000), we conducted a prospective study analyzing the effect of Nd:YAG posterior capsulotomy on the quantity of aqueous particles, aqueous flare, and intraocular pressure in 65 eyes (58 patients). Aqueous particles increased at six hours, followed by flare rise which was significant at 18 hours after capsulotomy. Only 22 eyes (34%) had a significant flare rise over prelaser values. Anti-inflammatory therapy was necessary in only one patient. The mean intraocular pressure value did not rise significantly after capsulotomy. Acute intraocular hypertension (AIOHT) (> 7 mm Hg increase) occurred between three and six hours after laser therapy in 12 patients (19%), was related in time to particle rise, and always responded to a single dose of acetazolamide. Acute intraocular hypertension was strongly correlated with elevated aqueous particles (P < .0001) and somewhat correlated with flare rise (P < .036), but was not correlated with the intraocular lens position (bag or sulcus fixation). Our findings strongly suggest that trabecular meshwork clogging by debris generated by the capsulotomy is the mechanism at the origin of AIOHT.

National outcomes of cataract extraction. Increased risk of retinal complications associated with Nd:YAG laser capsulotomy. The Cataract Patient Outcomes Research Team

PURPOSE

The authors studied 57,103 randomly selected Medicare beneficiaries who underwent extracapsular cataract extraction in 1986 or 1987 to determine the possible association between performance of neodymium (Nd):YAG laser capsulotomy and the risk of subsequent retinal break or detachment.

METHODS

Cases of cataract surgery were identified from Medicare claims submitted in 1986 and 1987 and were followed through the end of 1988. Episodes of cataract surgery, posterior capsulotomy, and retinal complications were ascertained based on procedure and diagnosis codes listed in physician bills and hospital discharge records. Lifetable and Cox's proportional hazards models were used to analyze the risk of retinal detachment or break in patients undergoing and not undergoing capsulotomy during the period of observation.

RESULTS

Of the 57,103 persons identified as having undergone extracapsular cataract extraction in 1986 or 1987, 13,709 subsequently underwent Nd:YAG laser capsulotomy between 1986 and 1988. A total of 337 persons had aphakic or pseudophakic retinal detachments between 1986 and 1988 and an additional 194 underwent repair of a retinal break. Proportional hazards modeling shows a 3.9-fold increase in the risk of retinal break or detachment among those who underwent capsulotomy (95% confidence interval: 2.89 to 5.25). Younger patient age, male sex, and white race also were associated with increased risk of retinal complications after extracapsular cataract extraction.

CONCLUSION

The authors conclude that there is a statistically significant increase in the risk of retinal detachment or break in those patients who undergo capsulotomy after cataract extraction. Therefore, capsulotomy should be deferred until the patient's impairment caused by capsular opacification warrants the increased risk of retinal complications associated with performance of capsulotomy.

Posterior capsule opacification

A complication of extracapsular cataract extraction with or without posterior chamber intraocular lens (PC-IOL) implantation is posterior capsule opacification. This condition is usually secondary to a proliferation and migration of residual lens epithelial cells. Opacification may be reduced by atraumatic surgery and thorough cortical clean-up. Clinical, pathological and experimental studies have shown that use of hydrodissection, the continuous curvilinear capsulorhexis and specific IOL designs may help reduce the incidence of this complication. Capsular-fixated, one-piece all-polymethylmethacrylate PC-IOLs with a C-shaped loop configuration and a posterior convexity of the optic are effective. Polymethylmethacrylate loops that retain "memory" create a symmetric, radial stretch on the posterior capsule after in-the-bag placement, leading to a more complete contact between the posterior surface of the IOL optic and the taut capsule. This may help form a barrier against central migration of epithelial cells into the visual axis. Various pharmacological and immunological methods are being investigated but conclusive data on these modalities are not yet available.

The Binkhorst Medal Lecture. Biologic relationship between poly(methyl methacrylate) intraocular lenses and uveal tissue

Implantation of a poly(methyl methacrylate) (PMMA) intraocular lens (IOL) after cataract surgery is associated with breakdown of the blood-ocular barrier and a foreign body inflammatory response. Although the material is biocompatible, it is not inert. The history of PMMA IOL implantation has reflected mechanical, chemical, and immunological interactions between the IOL and ocular tissues. The common link in these events is instability of the blood-ocular barrier. In this lecture, I discuss the nature of these interactions and present evidence that currently investigated methods of surface modification and capsular bag IOL implantation are effective in stabilizing the blood-ocular barrier.

Cystoid macular oedema following neodymium:YAG laser capsulotomy a prospective study

Neodymium:YAG laser capsulotomy was performed in 65 eyes of 65 patients because of vision loss due to posterior capsular opacification or wrinkling following uneventful extracapsular cataract extraction with intraocular lens implantation. Eyes with pre-existing macular pathology were excluded from this study. In all of the eyes the posterior capsule was successfully opened. None developed clinical or angiographic cystoid macular oedema. One eye developed retinal detachment nine months after capsulotomy.

Cystoid macular edema, retinal detachment, and glaucoma after Nd:YAG laser posterior capsulotomy

A series of 897 Nd:YAG laser posterior capsulotomies were reviewed for the complications of cystoid macular edema, retinal detachment, new onset of glaucoma, and worsened preexisting glaucoma. After Nd:YAG capsulotomy, 11 patients (1.23%; 95% confidence interval, 0.51% to 1.95%) developed cystoid macular edema and eight patients (0.89%; 95% confidence interval, 0.28% to 1.5%) developed a retinal detachment. The new onset of glaucoma was observed in seven patients (0.78%; 95% confidence interval, 0.20% to 1.36%). Five patients (0.56%; 95% confidence interval, 0.07% to 1.05%) with preexisting glaucoma had persistent worsening of their glaucoma. Most patients with a complication had no identifiable risk factors in common. The numbers of laser pulses and energy delivered were not risk factors. Retinal detachment and cystoid macular edema developed most often many months after capsulotomy and many months to years after the cataract surgery. Patients undergoing Nd:YAG laser capsulotomy therefore require ongoing medical observation to detect and treat these serious complications.

Intercapsular cataract surgery with lens epithelial cell removal. Part III: Long-term follow-up of posterior capsular opacification

In 144 eyes in 144 patients with senile cataract the rate of posterior capsular opacification requiring YAG capsulotomy up to 36 months following intercapsular cataract surgery with lens epithelial cell removal using ultrasound and aspiration was evaluated and compared to the rate for 471 senile cataractous eyes in patients who had had posterior chamber lens implantation following phacoemulsification and extracapsular cataract extraction without lens epithelial cell removal. Posterior capsular opacification occurred in 3.7% of patients who had lens epithelial cell removal, significantly less (P less than .01) than the 10.8% found in the control group. Lens epithelial cell removal is considered an effective method of preventing capsular opacification.

Posterior chamber intraocular lens implantation in eyes with inactive and active proliferative diabetic retinopathy

We reviewed the records of 2,100 consecutive eyes that had undergone extracapsular cataract extraction with intraocular lens implantation between January 1981 and December 1989. Of these eyes, 21 had inactive and four had active proliferative diabetic retinopathy at the time of cataract extraction. Twenty-one eyes with inactive proliferative diabetic retinopathy received extracapsular cataract extraction with posterior chamber intraocular lens implantation, and four eyes with active proliferative diabetic retinopathy had both extracapsular cataract extraction with posterior chamber intraocular lens implantation and pars plana vitrectomy with endophotocoagulation. The mean follow-up period was 27 months. Final visual acuity was 20/40 or better in 12 of 25 eyes (48%). Of 25 eyes, five (20%) showed progression of the retinopathy after the operation, and two (8%) developed macular edema. Extracapsular cataract extraction and posterior chamber intraocular lens implantation was well tolerated in most eyes.

Pathogenesis of posterior capsular opacification. Part I. Epidemiological and clinico-statistical data

We examined 895 eyes having extracapsular cataract surgery; 403 had an intraocular lens (IOL) implanted and 492 did not. The incidence of posterior capsular opacification was 7.69% in the eyes with an IOL and 14.23% in the eyes without an IOL. If we exclude complicated cataracts from the cases that did not have an IOL, the incidence of posterior capsular opacification decreases to 9.06%. Various models of implanted IOLs showed different incidences of posterior capsular opacification: For J-looped lenses the incidence was 11.02%; for Frezzotti-Caporossi lenses, 7.35%. The follow-up was too short for soft lenses. The Frezzotti-Caporossi lens can be inserted with the convex side either anterior or posterior. A statistical evaluation shows that the reverse optic or posterior convex orientation in the bag caused a lower incidence of posterior capsular opacification (3.01%).

Retinal detachment following YAG laser capsulotomy

A retrospective study of 12 patients with rhegmatogenous retinal detachment following YAG posterior capsulotomy is reported. Eleven out of these 12 were at increased risk of detachment. Three had lattice degeneration, three had previous detachment and five had axial myopia. Only 50% of the holes were typical "aphakic" post-oral breaks.

Effect of the laser ridge on posterior capsule opacification

The most common complication of extracapsular cataract extraction is posterior capsule opacification, which appears to result from the proliferation of anterior lens epithelium onto the posterior capsule. The presence of a posterior chamber intraocular lens has been shown to decrease the incidence of posterior capsule opacification, possibly by a barrier mechanism. This retrospective clinical study compares the effect of two different lens designs (with and without a laser ridge) on posterior capsule opacification requiring Nd:YAG laser posterior capsulotomy. Twenty-one of 101 patients (20.8%) with nonridged lenses required Nd:YAG laser posterior capsulotomies versus 13 of 86 patients (15.1%) with ridged lenses. Although these data showed a clinical benefit from using a ridged lens, no statistical difference in the incidence of posterior capsulotomy was noted. Further evaluation of capsular-optic surface apposition is needed.

Retrospective study of retinal detachment following neodymium:YAG laser posterior capsulotomy

A retrospective study of 1,000 cases that had Nd:YAG laser posterior capsulotomy after cataract surgery is presented. We analyzed the correlation of the patient's age, axial length of the eye, method of cataract surgery, and laser parameters (exposures, energy, and burst mode) with the incidence of retinal detachment (1.6% overall). The highest risk for retinal detachment (12.3%) was in patients with an axial eye length of 26.1 mm to 28.0 mm. The average age of patients with retinal detachments was 60.6 years, ten years younger than the collective average age. Laser parameters, such as energy, exposures, and burst mode, and the method of cataract surgery (extracapsular or phacoemulsification) did not correlate with the incidence of retinal detachment. After surgical treatment of the 16 retinal detachments, a good postoperative visual acuity (better than 20/40) was achieved in most cases.

Retinal tears and detachments after extracapsular cataract surgery

A review of 3,120 consecutive cases of extracapsular cataract extraction revealed a retinal detachment incidence of 0.8% and a retinal tear incidence of 0.9%. Approximately 85% of all tears and detachments occurred within the first three years of cataract surgery. Analysis of the retinal detachment group identified several risk factors. These included young age, male sex, axial length greater than 25 mm, primary posterior capsulotomy, and previous retinal surgery in the fellow eye. In the retinal tear group, the risk factors were young age and previous retinal surgery in the fellow eye. Visual results were excellent with an average of one line of acuity lost after successful macula-on and macula-off detachment surgery and no significant change after retinal tear repair. Despite multiple surgeries, the retinas in two detachments were lost to proliferative vitreoretinopathy.