Incidence and progression of epiretinal membranes in eyes after cataract surgery.

PURPOSE: To assess eye-specific epiretinal membrane (ERM) incidence 3 years after phacoemulsification surgery, and ERM detection bias attributable to cataract.
DESIGN: Cohort study.
METHODS: We recruited 1932 cataract surgical patients aged ≥64 years at Westmead Hospital (2004-2007). The surgical eye of each patient was assessed for presence of cellophane reflex or preretinal fibrosis at preoperative and 1-month-postoperative visits, and annually thereafter, using retinal image grading. Agreement on ERM detection between preoperative and 1-month-postoperative visits was assessed using kappa statistics. Cumulative incidence of ERM from 1 month to 3 years postoperatively was estimated using Kaplan-Meier methods and compared to the 5-year incidence of idiopathic ERM in right eyes of age-matched Blue Mountains Eye Study (BMES) participants.
RESULTS: ERM prevalence was 13.9% among 1394 participants with retinal photographs taken 1 month postoperatively. Of 1040 participants with retinal photographs from both preoperative and 1-month-postoperative visits, ERM was detected in 3.1% and 14.8%, respectively, with low diagnostic agreement (kappa = 0.17). Of 1119 subjects without ERM 1 month post surgery, the 3-year cumulative incidence of ERM was 11.2% (95% confidence interval [CI], 9.4%-13.4%; cellophane reflex 6.6%; preretinal fibrosis 4.2%). The age-standardized 3-year incidence of ERM in the surgical cohort (12.1%, 95% CI 8.6%-16.9%) was higher than the 5-year incidence of the BMES subsample (4.4%, 95% CI 3.0%-6.0%).
CONCLUSIONS: A substantial under-detection of ERM in eyes before cataract surgery could incorrectly contribute to ERM incidence after surgery. Over 3 years, ERM developed in >10%, including preretinal fibrosis in 4%, of surgical eyes free of ERM 1 month post surgery.