Early Markers of Choroidal Neovascularization in the Fellow Eye of Patients with Unilateral Exudative Age-Related Macular Degeneration

Abstract

Objective: To identify morphological and/or functional early markers of choroidal neovascularization (CNV) development in fellow eyes of patients with exudative age-related macular degeneration (AMD). Design: This is a single-center, prospective, observational, longitudinal 2-year study. Patients: Patients were enrolled with the diagnosis of neovascular AMD in 1 eye and early age-related maculopathy (ARM) in the fellow eye. Intervention or Methods: All patients completed the baseline assessment and were followed up for up to 24 months with repeated ophthalmic and imaging assessments performed at 6-month intervals. Main OutcomeMeasures: Each patient underwent a detailed ocular and medical history, a complete ophthalmologic examination with color fundus photography, fluorescein angiography, indocyanine green angiography (ICG), optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging and retinal leakage analysis (RLA). Results: Sixty-two patients were enrolled in the study. Large or intermediate drusen were present in 100% of the study eyes and hyperpigmentation in 46% (24 eyes). Fifty-two patients completed the 2-year study follow-up. Large soft drusen (>125 µm) were observed in 15 out of 17 eyes (88%) that converted and developed CNV during the study and in 25 out of 35 eyes (71.4%) that did not develop CNV. Among the 17 eyes that developed CNV, 9 (53%) showed abnormal findings before conversion, on ICG. No particular FAF pattern was found to be correlated with conversion to wet AMD. OCT was able to document the presence of intra- or subretinal fluid at the time of conversion in all 17 eyes that developed CNV during the study. Alterations of the blood-retinal barrier were identified by RLA before conversion in 76% of the eyes that converted and 23% of the eyes that did not convert during the study. Conclusions: Characterization of early ARM phenotypes is challenging. By combining different imaging modalities of the macula and correlating this information, we were able to determine the presence of functional macular alterations in the fellow eye of patients with this disease before development of CNV.