Cataract Surgery and the Risk of Conversion from Dry to Neovascular Age-related Macular Degeneration in the IRIS© Registry.

Abstract

To evaluate the association between cataract surgery (CS) and the risk of conversion from dry age-related macular degeneration (dAMD) to neovascular AMD (nvAMD), and to identify factors associated with conversion. Population-based retrospective time-to-event study SUBJECTS: Eyes of patients aged ≥55 years with early or intermediate dAMD and phakic status at baseline were identified in the American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight) on or after January 1st, 2016, to December 31st, 2022. Eyes that underwent CS were classified as exposed; those without CS during the study period were nonexposed. Propensity score matching was used to match eyes 1:1 on age, sex, race, and ethnicity, laterality, AMD stage, and smoking status. CS was modeled as a time-varying exposure. We used Cox proportional hazards regression to estimate the hazard of conversion to nvAMD. Conversion from dAMD to nvAMD, defined by registry-derived diagnosis codes, between exposed and nonexposed cohorts. After matching, 40,053 eyes were included in each exposed and nonexposed cohort (total N = 80,106 eyes). CS was associated with a higher risk of nvAMD conversion (hazard ratio [HR] = 1.22; 95% CI, 1.16-1.30; P < 0.001). Time-varying analysis demonstrated that this association was strongest early in follow-up (HR ≈ 2.5 in year 1) and declined steadily, reaching non-significance (HR ≈ 1.0) by year 4. At year 6, the cumulative incidence of nvAMD was 17.7% in the exposed cohort versus 15.2% in the nonexposed cohort. Baseline AMD stage moderated the effect of CS, with weaker effects of CS for intermediate AMD (Interaction HR = 0.82, 95% CI, 0.78-0.92). CS was associated with a modestly increased overall rate of conversion from dAMD to nvAMD; however, the time-dependent pattern suggests that the observed association likely reflects increased surveillance or unrecognized pre-existing nvAMD rather than a sustained biological effect of surgery. The absolute risk difference was small (∼3.3% over six years). These findings support careful perioperative evaluation in dAMD patients but do not implicate CS as a long-term driver of neovascular conversion.