Cataract Surgery and the Risk of Conversion from Dry to Neovascular Age-Related Macular Degeneration in the IRIS® Registry (Intelligent Research in Sight).

PURPOSE: 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.

DESIGN

Population-based retrospective time-to-event study.

PARTICIPANTS

Eyes of patients 55 years of age or older 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 1, 2016, through December 31, 2022. Eyes that underwent CS were classified as exposed; those without CS during the study period were classified as nonexposed.

METHODS

Propensity score matching was used to match eyes 1:1 on age, sex, race and ethnicity, laterality, AMD stage, and smoking status. Cataract surgery was modeled as a time-varying exposure. We used Cox proportional hazards regression to estimate the hazard of conversion to nvAMD.

MAIN OUTCOME MEASURES: Conversion from dAMD to nvAMD, defined by registry-derived diagnosis codes, between exposed and nonexposed cohorts.

RESULTS

After matching, 40 053 eyes were included in each exposed and nonexposed cohort (n = 80 106 eyes total). Cataract surgery was associated with a higher risk of nvAMD conversion (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.16-1.30; P < 0.001). Time-varying analysis demonstrated that this association was strongest early in follow-up (HR, approximately 2.5 in year 1) and declined steadily, reaching nonsignificance (HR, approximately 1.0) by year 4. At year 6, the cumulative incidence of nvAMD was 17.7% in the exposed cohort vs 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, 0.73-0.92).

CONCLUSIONS

Cataract surgery 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 preexisting nvAMD, rather than a sustained biological effect of surgery. The absolute risk difference was small (approximately 3.3% over 6 years). These findings support careful perioperative evaluation in patients with dAMD, but do not implicate CS as a long-term driver of neovascular conversion.

FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.