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

The assessment of changes in macular thickness in diabetic and non-diabetic patients: the effect of topical ketorolac on macular thickness change after ND:YAG laser capsulotomy

PURPOSE

The purpose of our study is to assess the changes in macular thickness (MT) in diabetic and non-diabetic patients and to research effects of topical ketorolac (Acular®, Allergan, Irvine, CA) on MT change after neodymium:yttrium aluminum garnet (Nd:YAG) laser capsulotomy.

MATERIAL AND METHODS

This study involved 88 eyes of 88 patients diagnosed as posterior capsule opacification (PCO). Patients were divided into four groups according to presence of diabetes mellitus (DM) and drugs used after capsulotomy. Group 1: Patients with DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy (22 patients). Group 2: Patients with DM using 0.5% ketorolac (Acular®) and 0.1 Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy (20 patients). Group 3: Patients without DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (22 patients). Group 4: Patients without DM using 0.5% ketorolac (Acular®) and 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (24 patients). A plus-shaped capsulotomy was performed using VISULAS® YAGIII (Carl Zeiss) laser microscope. MT measurement with Cirrus SD-OCT (Carl Zeiss Opthalmic System Inc., Model 400, Dublin, CA, Software 5) were done. Measurements were done before laser, and on the first day, first week, first month, third month and sixth month after laser capsulotomy. We compared the four groups for MT change during 6 months.

RESULTS

Group 1 involving patients with DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy had increased MT at the first week, and the first, third, and sixth month after laser (p < 0.001). Group 3 involving patients without DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) had increased MT at the first week, and at the first and third month, there was no statistically significant difference at the sixth month (p > 0.05). There was no statistically significant increase in MT during the follow-up period in group 2 involving patients with DM using 0.5% ketorolac (Acular®) and 0.1 Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy and group 4 involving patients without DM using 0.5% ketorolac (Acular®) and 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (p > 0.05).

CONCLUSION

An increase in MT can be observed after Nd:YAG laser capsulotomy, especially in diabetic patients. Adding topical ketorolac (Acular®, Allergan, Irvine, CA) to topical Fluorometholon (FML®, Allergan, Irvine, CA) therapy after YAG laser capsulotomy can prevent this increase.

Posterior capsule opacification after extra capsular cataract extraction in Indian rural population: foldable acrylic vs poly (methyl-methacrylate) intraocular lenses a randomized clinical trial

PURPOSE

To compare the performance of single-piece acrylic vspoly (methylmethacrylate) intraocular lenses (IOL) on the development of posterior capsule opacification (PCO) after conventional extra capsular cataract extraction (ECCE).

MATERIALS AND METHODS

One hundred and eighty-two eyes of 91 patients with bilateral senile cataract undergoing ECCE were prospectively randomized to receive a single-piece Alcon AcrySof SA60AT IOL or a single-piece EPOCH polymethylmethacrylate IOL in the first eye to have surgery. At 1, 6 and 12 months post-operative follow-up, digital retro illumination images of the posterior capsule were taken for PCO assessment semi-objectively using PCO (POCO automated analysis software) system. Relationship of anterior capsule contact (total off and partial cover) on optic for PCO was analyzed.

RESULTS

The AcrySof IOL was associated with less PCO than EPOCH lens at 6 months (10.01+/-8.75% vs 32.26+/-27.44%; P<0.001) and 1-year (11.65+/-10.55% vs 38.38+/-29.62%; P<0.001) follow-up. The EPOCH IOL showed a remarkably significant difference on development of PCO with anterior capsule overlap on IOL optic (total off and part on) 1 year (P<0.039), whereas no such difference was observed with the AcrySof IOL (P=0.197).

CONCLUSION

The AcrySof IOL led to significantly less PCO than the EPOCH IOL post-operatively after extracapsular cataract extraction.

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

PURPOSE

To investigate the influence of optic edge design on posterior capsule opacification (PCO) and anterior capsule contraction (ACC).

METHODS

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.

RESULTS

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.

CONCLUSIONS

A sharp IOL edge is required to prevent PCO. Sharp-edged IOLs do not appear to be a risk factor for ACC.

Prospective evaluation of phacoemulsification in adults younger than 50 years

PURPOSE

To evaluate intraoperative performance and long-term outcome of phacoemulsification in patients younger than 50 years.

SETTING

Iladevi cataract and IOL Research Centre, Ahmedabad, India.

METHODS

A prospective observational study was conducted comprising 54 patients (35 men and 19 women) under age 50 who had phacoemulsification. Preoperative evaluation included specular microscopy. Phacoemulsification with implantation of an AcrySof MA30BA intraocular lens (IOL) was performed. Intraoperatively, peripheral extension of capsulorhexis, intraoperative posterior capsule opacification (PCO; plaque), and serious complications (eg, posterior capsule rupture, vitreous loss) were noted. Postoperatively, endothelial cell loss, postoperative PCO, neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate, and best corrected visual acuity (BCVA) were assessed for 3 years. Patients with intraoperative PCO were analyzed separately.

RESULTS

Mean patient age was 42.7 years +/- 5.2 SD (men) and 43.1 +/- 3.25 years (women). Continuous curvilinear capsulorhexis was achieved in 49 patients (90.7%). Intraoperative PCO was present in 14 (25.92%) patients. An Nd:YAG laser posterior capsulotomy was performed in 4 patients (28.5%). Posterior capsule rupture leading to vitreous loss occurred in 1 patient (1.85%). At 3-year follow-up, endothelial cell loss was 5.9%. Postoperative PCO developed in 8 patients (22.2%), and Nd:YAG laser posterior capsulotomy was performed in 5 patients (13.8%). The BCVA was > or = 20/40 in 47 patients (94%).

CONCLUSION

Young patients pose a challenge in creating a capsulorhexis and display significant incidence of intraoperative and postoperative PCO.

Three-year follow-up of posterior capsule opacification with two different silicone intraocular lenses

PURPOSE

To compare posterior capsule opacification (PCO) after cataract surgery with implantation of two silicone intraocular lenses (IOLs) with different designs.

METHODS

We carried out a prospective, clinical study of 116 patients randomized to standardized phacoemulsification with implantation of CeeOn Edge (n = 57) or SI40NB (n = 59) IOLs. The follow-up period was 3 years. To evaluate PCO morphologically, digital images were obtained and analysed using evaluation of posterior capsule opacification computer software (epco). The neodymium:YAG (Nd:YAG) capsulotomy rate was recorded.

RESULTS

At 2 and 3 years, the eyes with SI40NB IOLs had significantly more PCO than those with the CeeOn Edge IOLs (p = 0.00014 and p = 0.002). Nine Nd:YAG capsulotomies were performed in the SI40NB group and none in the CeeOn Edge group. This difference was statistically significant (p = 0.003). In some patients a regression of PCO was noticed and confirmed using epco. Statistically less PCO was noted when the capsulorhexis rim was placed so that it covered all 360 degrees of the optic of the IOL.

CONCLUSIONS

A clinically and statistically significant difference in PCO development between CeeOn Edge and SI40NB IOLs at 2 and 3 years postoperatively was found. These findings support earlier studies indicating that a sharp edge of the optic is a more important factor in IOL design than IOL material in the prevention of PCO.

Relationship between anterior capsule contraction and posterior capsule opacification after cataract surgery in patients with diabetes mellitus

PURPOSE

To prospectively assess the relationship between contraction of the anterior capsule opening and posterior capsule opacification (PCO) after cataract surgery in patients with diabetes mellitus.

SETTING

Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Kaiya Eye Clinic, Hamamatsu, and Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaragi, Japan.

METHODS

This study comprised 45 patients (45 eyes) with diabetes mellitus who had cataract surgery. In all eyes, the anterior capsule opening area and degree of PCO were determined by diaphanoscopy using an anterior eye segment analysis system (EAS-100, Nidek, Inc.) 1 day and 1 year postoperatively.

RESULTS

There was no correlation between the size of the anterior capsule opening area 1 day after surgery and the degree of PCO 1 year after surgery (Pearson correlation coefficient [r] = 0.041; P =.79). The percentage reduction in the anterior capsule opening area from 1 day to 1 year after surgery did not correlate with the degree of PCO 1 year after surgery (r = -0.08; P =.60).

CONCLUSION

Contraction of the anterior capsule opening and PCO after cataract surgery cannot be explained by a common mechanism.

Anterior capsule relationship of the AcryS of intraocular lens optic and posterior capsule opacification

OBJECTIVE

To evaluate the relationship of the anterior capsule and the AcrySof MA30BA intraocular lens (IOL) and its impact on the development of central posterior capsule opacification (PCO).

DESIGN

Prospective, randomized, controlled trial.

PARTICIPANTS

Two hundred two patients with senile cataracts received an AcrySof IOL between July and December 1998 at Iladevi Cataract and IOL Research Center, Ahmedabad, India.

INTERVENTION

Patients were randomized prospectively to receive 1 of the 3 possibilities of anterior capsule and IOL optic relationship: group 1, total anterior capsule cover (360 degrees ) of the optic; group 2, no anterior capsule cover (360 degrees ) of the optic; group 3, partial anterior capsule cover (<360 degrees ) of the optic. After surgery, slit-lamp video photography was performed every 6 months for 3 years. Analyses of variance and chi-square tests were used to compare treatment groups.

MAIN OUTCOME MEASURES

Incidence of PCO in the 3 groups. The posterior capsule was divided into 3 zones: peripheral, central 3 mm, and midperipheral (the space between the peripheral and the central zones).

RESULTS

The average follow-up was 35.3 +/- 1.52 months in all the groups. At 3 years, the rate of central PCO was 6.4% in group 1, 7.1% in group 2, and 5.9% in group 3 (P = 0.9). Midperipheral PCO was present in 24.2% in group 1, 16% in group 2, and 20.6% in group 3 (P = 0.9). Peripheral PCO was seen in 100% of patients in all groups. The neodynium:yttrium-aluminum-garnet laser (Nd:YAG) posterior capsulotomy rate was 0% in all groups.

CONCLUSIONS

There was no significant difference in the incidence of development of central PCO among the 3 groups. No patient experienced central PCO that required Nd:YAG capsulotomy. When using the AcrySof IOL model MA30BA, the relationship of the anterior capsule and the IOL does not seem to be a factor that relates to the development of central PCO.

Cumulative probability of neodymium: YAG laser posterior capsulotomy after phacoemulsification

PURPOSE

To retrospectively analyze the cumulative probability of neodymium:YAG (Nd:YAG) laser posterior capsulotomy after phacoemulsification and to evaluate the risk factors.

SETTING

Ando Eye Clinic, Kanagawa, Japan.

METHODS

In 3997 eyes that had phacoemulsification with an intact continuous curvilinear capsulorhexis, the cumulative probability of posterior capsulotomy was computed by Kaplan-Meier survival analysis and risk factors were analyzed using the Cox proportional hazards regression model. The variables tested were sex; age; type of cataract; preoperative best corrected visual acuity (BCVA); presence of diabetes mellitus, diabetic retinopathy, or retinitis pigmentosa; type of intraocular lens (IOL); and the year the operation was performed. The IOLs were categorized as 3-piece poly(methyl methacrylate) (PMMA), 1-piece PMMA, 3-piece silicone, and acrylic foldable.

RESULTS

The cumulative probability of capsulotomy after cataract surgery was 1.95%, 18.50%, and 32.70% at 1, 3, and 5 years, respectively. Positive risk factors included a better preoperative BCVA (P =.0005; risk ratio [RR], 1.7; 95% confidence interval [CI], 1.3-2.5) and the presence of retinitis pigmentosa (P<.0001; RR, 6.6; 95% CI, 3.7-11.6). Women had a significantly greater probability of Nd:YAG laser posterior capsulotomy (P =.016; RR, 1.4; 95% CI, 1.1-1.8). The type of IOL was significantly related to the probability of Nd:YAG laser capsulotomy, with the foldable acrylic IOL having a significantly lower probability of capsulotomy. The 1-piece PMMA IOL had a significantly higher risk than 3-piece PMMA and 3-piece silicone IOLs.

CONCLUSIONS

The probability of Nd:YAG laser capsulotomy was higher in women, in eyes with a better preoperative BCVA, and in patients with retinitis pigmentosa. The foldable acrylic IOL had a significantly lower probability of capsulotomy.

Inhibition of lens epithelial cell growth by induction of apoptosis: potential for prevention of posterior capsule opacification

As a model of the cell proliferation occurring in posterior capsule opacification (PCO), lens epithelial cells (LEC) from human and rabbit capsulotomies, and a rabbit LEC line (N/N1003A) were grown in Dulbecco's Minimal Essential Media (MEM) with 10% fetal calf serum. LEC were exposed to the calcium ionophore, calcimycin, and viability was assessed by trypan blue staining, growth by 3H-thymidine incorporation and apoptosis by annexin/propidium iodide staining, calcein AM/ethidium bromide staining and DNA laddering. Human capsulotomy samples were similarly exposed to calcimycin, and apoptosis assayed by calcein AM/ethidium bromide staining. Calcimycin exposure induced apoptosis in both rabbit LEC cultures and human LEC, and changes leading to apoptosis could be detected within 30 minutes of calcimycin treatment. The decrease in viability and growth in human and rabbit LEC was dose-dependent. These data support the further evaluation of apoptosis induction as a possible treatment mechanism to prevent development of PCO following primary cataract surgery in humans.

Posterior capsule opacification with AcrySof and poly(methyl methacrylate) intraocular lenses. Comparative study with a 3-year follow-up

PURPOSE

To evaluate whether reports of reduced posterior capsule opacification (PCO) rates with AcrySof intraocular lenses (IOLs) are applicable to a mixed group of cataract patients in everyday surgical practice.

SETTING

Department of Ophthalmology, Kärnsjukhuset, Skövde, Sweden.

METHODS

A retrospective study comparing a study group receiving an AcrySof IOL (n = 145) and a group receiving a poly(methyl methacrylate) (PMMA) IOL (n = 153) was performed. The follow-up was 3 years in both groups. The performance of a neodymium:YAG laser capsulotomy was used as the end point for clinically significant PCO.

RESULTS

Nine capsulotomies (6.2%) were performed in the AcrySof group and 34 (22.2%) in the PMMA group. The difference in the capsulotomy rate between the 2 groups was highly significant (P <.001). The relative risk was 3.6 times higher in the PMMA group.

CONCLUSIONS

There was a significant difference in the frequency of capsulotomy between AcrySof and PMMA IOLs in a mixed group of cataract patients in everyday clinical practice. This finding indicates the importance of the IOL type in PCO formation.

Lack of correlation between intraocular inflammation and after-cataract formation in the rabbit eye

PURPOSE

To determine whether an increased or reduced inflammatory response following cataract surgery influences the development of after-cataract.

SETTING

Department of Preclinical Ophthalmology, Pharmacia, Uppsala, Sweden.

METHODS

Rabbits that had had cataract surgery were given endotoxin, ovalbumin, dexamethasone, or diclofenac. Aqueous humor, leukocytes, and prostaglandin E(2) (PGE(2)) were analyzed, and the wet weight of the after-cataract was determined.

RESULTS

The wet weight of the after-cataract was unaffected by endotoxin and 67% lower in the eyes treated with ovalbumin than in the control eyes on day 56. Aqueous humor concentrations of leukocytes and PGE(2) were 94% and 87% lower in the group treated with dexamethasone than in the control group on day 7, and the concentration of PGE(2) was 98% lower in the diclofenac group; however, the wet weight of the after-cataract was unaffected by both treatments.

CONCLUSION

This study suggests that an increased inflammatory response does not increase the development of after-cataract and a reduction in the inflammatory response does not reduce the development of after-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.

Secondary closure of posterior continuous curvilinear capsulorhexis in normal eyes and eyes at risk for postoperative inflammation

PURPOSE

To observe the posterior continuous curvilinear capsulorhexis (PCCC) after cataract surgery in control eyes and eyes with an increased risk for postoperative inflammation.

SETTING

Department of Ophthalmology, University Hospital Antwerp, Belgium.

METHODS

After phacoemulsification, a PCCC was performed before intraocular lens (IOL) implantation in 20 eyes of 18 patients with ocular or systemic conditions that predisposed them for increased postoperative inflammation; e.g., diabetes, uveitis, retinitis pigmentosa (inflammation group). These eyes were compared with 20 eyes of 16 patients who had the same surgical procedure but did not present a history of medical or ocular pathology (control group). The postoperative follow-up was 6 months to 3 years. Reclosure of the PCCC was evaluated by anterior segment photographs. The reclosure was classified as partial when newly formed tissue was present at the PCCC margin and total when the proliferation covered the entire PCCC area.

RESULTS

Three types of PCCC reclosure were found: fibrotic, Elschnig pearl or multilayer, and monolayer. All 3 were seen within or at the margin of the PCCC area. Reclosure (total and partial) occurred in 8 eyes (40%) in the control group and 10 (50%) in the inflammation group. Total reclosure was more frequent in the inflammation group (4 eyes [20%]) than in the control group (1 eye [5%]). Monolayered or multilayered cellular proliferation was present in 8 eyes (40%) in the control group and 4 eyes (20%) in the inflammation group; fibrotic proliferation was found in the inflammation group only (7 eyes [35%]).

CONCLUSION

Reclosure of the PCCC occurred in both groups, although the frequency of reclosure was slightly higher in the inflammation group. Although PCCC does not prevent posterior capsule opacification in all cases, it is useful in specific situations.

Effect of intraocular lens design on neodymium:YAG laser capsulotomy rates

PURPOSE

To compare the effect of 2 poly(methyl methacrylate) (PMMA), 1-piece biconvex intraocular lens (IOL) designs on the cumulative frequency of neodymium:YAG (Nd:YAG) laser posterior capsulotomy.

SETTING

Department of Ophthamology, Mayo Clinic, Rochester, Minnesota, USA.

METHODS

This retrospective study evaluated 369 eyes that had phacoemulsification with continuous curvilinear capsulorhexis (CCC) and IOL implantation in the capsular bag. Patients were placed in 1 of 2 groups based on the 1-piece, biconvex PMMA IOL design: large IOL, with a lens diameter of 13.50 to 13.75 mm, optic size of 6.5 mm, and 10 degree haptic angulation; small capsular IOL, with a lens diameter of 12.0 to 12.5 mm, optic size of 5.5 mm, and 2 degree haptic angulation.

RESULTS

Using Kaplan-Meier analysis, the frequency of Nd:YAG laser posterior capsulotomy 1, 2, and 3 years after cataract surgery was 1.6, 12.3, and 26.5%, respectively, in the large IOL group and 3.4, 9.5, and 23.5%, respectively, in the small capsular IOL group. The cumulative frequency of Nd:YAG laser capsulotomy was not statistically different between the 2 groups.

CONCLUSION

After phacoemulsification and CCC, there was no significant difference in the Nd:YAG laser capsulotomy rate in eyes with a small, capsular design, 1-piece, biconvex PMMA IOL and those with a larger, angulated, 1-piece, biconvex PMMA IOL.

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-plano 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-plano laser-ridge IOL than in those with an unmodified convex-plano 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-plano IOL with a laser ridge.

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.

Centration of intraocular lenses with circular haptics

PURPOSE

To evaluate two intraocular lens (IOL) models with a circular haptic configuration designed to better distribute forces within the capsular bag over 360 degrees.

SETTING

University and Maria Middelares hospitals, Antwerp, Belgium.

METHODS

Two IOLs with circular haptics were evaluated for 6 months after implantation: a one-piece, all-poly(methyl methacrylate) (PMMA), Corneal IS M 5.5 lens with a 5.5 mm biconvex optic, overall diameter of 9.8 mm, and two semicircular open haptics (n = 103); a plano-convex, all-PMMA, modified Anis lens with a 5.5 mm plano-convex optic, total diameter of 10.0 or 11.0 mm (depending on diopter), and closed-loop haptics (n = 335). All lenses were inserted through a 5.5 mm scleral incision after phacoemulsification and placed in the capsular bag through a 4.5 mm curvilinear capsulorhexis. The IOLs centered without being rotated.

RESULTS

Six months after implantation, the IOL optics were well centered, even in eyes with an eccentric capsulorhexis (19%). In two eyes with partial zonulysis and in seven with posterior capsule rupture, decentration of less than 0.5 mm was observed. Both lenses provided uniform capsular support without causing stress lines in the posterior capsule. There were no cases of capsule contraction syndrome. Posterior capsule fibrosis reducing visual acuity occurred in 4% of eyes in both series.

CONCLUSION

The Corneal IS M 5.5 and the Anis lens with circular haptics prevented late optic decentration and, therefore, would be useful in cases of eccentric capsulorhexis, partial zonulysis, anterior radial tears, and posterior capsule rupture. These IOLs may also prevent capsular contraction.

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.

Secondary closure of posterior continuous curvilinear capsulorhexis

PURPOSE

To examine the hypothesis that removing the center of the posterior capsule would prevent posterior capsular opacification (PCO).

SETTING

Department of Ophthalmology, University Hospital Antwerp, Belgium.

METHODS

A posterior continuous curvilinear capsulorhexis (CCC) was done before intraocular lens (IOL) implantation in eyes at risk for PCO (uveitic, young adult), retinal detachment after neodymium:YAG (Nd:YAG) laser capsulotomy (highly myopic) or for cystoid macular edema (uveitic, diabetic) and in eyes in which the posterior capsule was opaque intraoperatively. The 51 eyes of 40 patients had a follow-up ranging from 6 months to 2 years.

RESULTS

Four eyes (8%) developed partial closure of the posterior CCC without vision impairment; 6 eyes (12%) had total closure, of which 2 (4%) had a loss of two or more Snellen lines necessitating an Nd:YAG laser capsulotomy.

CONCLUSION

Young adult eyes and eyes with underlying diabetic retinopathy or uveitis are at risk for total closure of the posterior CCC. Only young adult eyes required Nd:YAG laser capsulotomy after the posterior CCC.

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 three-mirror 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.

Effect of intraocular lens design on posterior capsule opacification after continuous curvilinear capsulorhexis

We compared the effect of biconvex and convex-plano (posterior plano) intraocular lenses on posterior capsule opacification (PCO) following continuous curvilinear capsulorhexis (CCC) in 212 eyes. During the three years following surgery, the cumulative frequency of neodymium:YAG laser posterior capsulotomy, calculated with the Kaplan-Meier method, was significantly higher in patients in the biconvex group (32.5% by the third year) than in those in the convex-plano group (5.9% by the third year) (P < .05, Wilcoxon's test; P < .01, Cox-Mantel's test). Measured with the tracing method, the area within a 5 mm diameter central circle that developed Elschnig pearls was 2.93 +/- 4.91 mm2 in the biconvex group and 1.66 +/- 2.37 mm2 in the convex-plano group. In the study, PCO was less severe in the convex-plano group than in the biconvex group following CCC. These results are contrary to those reported previously in patients with can-opener capsulotomy.

Refraction and anterior chamber depth before and after neodymium: YAG laser treatment for posterior capsule opacification in pseudophakic eyes: a prospective study

Anterior chamber depth and refraction were evaluated in 52 pseudophakic eyes before and about one month after neodymium: YAG laser capsulotomy for posterior capsule opacification. External anterior chamber depth averaged 4.06 mm before and 4.07 mm after laser treatment, a statistically insignificant change. Mean spherical equivalent refraction before laser treatment, estimated from the prescription of spectacles, was 0.30 diopters (D). Mean subjective refraction after laser treatment was 0.24 D. The difference was not significant. Mean capsulotomy opening diameter increased from 3.44 mm +/- 0.61 mm (+/- SD) immediately after the laser treatment to 3.67 mm +/- 0.61 mm one month later. The increase was statistically significant. Intraocular lens position and spherical equivalent refraction did not change after the YAG laser capsulotomy, despite a significant increase in area of the capsulotomy opening.

Posterior capsule reopacification after neodymium:YAG laser capsulotomy

We report a case of complete posterior capsule reopacification after successful neodymium:YAG (Nd:YAG) capsulotomy in an adult. Review of the records of all patients who had an Nd:YAG capsulotomy at our hospital revealed an incidence of reopacification of 0.7%. All affected patients were younger than 50 years at the time of cataract surgery.