Purpose: To describe the incidence and characteristics of neovascularization in fellow eyes of Japanese patients with unilateral retinal angiomatous proliferation (RAP).
Methods: We retrospectively studied patients with unilateral RAP in one center between 2003 and 2010. The minimal follow-up time was 2 years. The prevalence rates of soft drusen and reticular pseudodrusen in the fellow eyes at the first visit were examined in color fundus photographs and optical coherence tomography images. Stepwise analysis was performed to identify a correlation between the incidence of RAP in the fellow eyes and age, gender, follow-up time, soft drusen, and reticular pseudodrusen.
Results: Twenty eyes were included in this study. The mean follow-up time was 49 months (range, 24-108 months). At the first visit, soft drusen was seen in 19 eyes (95%) and reticular pseudodrusen in 11 eyes (55%). Neovascular age-related macular degeneration developed in 10 eyes, including RAP in 9 eyes (45%) and polypoidal choroidal vasculopathy in 1 eye (5%). Stepwise analysis showed that reticular pseudodrusen and longer follow-up time were correlated significantly (P = 0.0384 and P = 0.0341, respectively) with the incidence of RAP.
Conclusion: Bilateral RAP developed in almost half of the eyes initially diagnosed with unilateral RAP and the incidence increased with time. Reticular pseudodrusen is a risk factor for bilateral RAP.