The Incidence of Neovascularization in the Fellow Eye of Patients with Unilateral Choroidal Lesion : a Survival Analysis

Purpose: To compare the difference in the rate of survival of unaffected fellow eyes between choroidal neovascularization (CNV) in the first eyes and retinal angiomatous proliferation (RAP) in the first eyes. Design: Cohort retrospective study. Participants: A total of 329 consecutive patients enrolled in our Eye Clinic between February 2006 and November 2014 were involved in the study. Only patients with naïve unilateral forms of neovascularization in 1 eye were included in this study. Methods: A clinical database containing patients’ data and ocular history was evaluated. Only patients with naive lesions in 1 eye and without signs of neovascular AMD in the fellow eye were included in the analysis. The time of absence of neovascularization in the fellow eye was calculated. Main Outcome Measures: Survival of the fellow eye was estimated by Kaplan–Meier analysis, and log-rank test was used to compare CNV and RAP fellow eye survival. Results: A total of 202 eyes affected by CNV and 39 eyes affected by RAP were enrolled in the study. The mean follow-up time was 2.9 years (range, 182–2461 days) for CNV and 2.6 years (range, 519–1504 days) for RAP. Kaplan–Meier analysis showed that the 50% of the fellow eyes with CNV did not develop neovascularization for 5.3 years, whereas the 50% of the fellow eyes with RAP did not develop neovascularization for 3.5 years. Log-rank test showed a highly significant difference between the 2 curves (P < 0.002). Conclusions: This study showed that the incidence of neovascularization in the unaffected fellow eye increases with time, and when the first eye is affected by RAP, the development of a lesion in the second eye is more premature.