Risk Factors for the Development of Choroidal Neovascularization in the Fellow Eye of Patients with Age Related Macular Degeneration - A Three Year Follow-up Study

Abstract

Purpose: : To identify morphological and functional risk factors for the development of Choroidal Neovascularization (CNV) in fellow eyes of patients with unilateral exudative AMD.

Methods: : Sixty-two patients with neovascular AMD in one eye (the non-study eye) and early ARM in the fellow eye (study eye), were enrolled in a single center, prospective, observational and longitudinal 2-year plus 1-year extension study. ETDRS Visual Acuity, Color Fundus Photography (CFP), Fluorescein (FA) and Indocyanine Green Angiography (ICG), Fundus Autofluorescence (FAF), Optical Coherence Tomography (OCT) and Retinal Leakage Analysis (RLA) were performed at the baseline and every 6 months, in order to identify conversion to CNV as well as possible predictive features present before conversion. Only eyes with 3 years of follow-up were considered for statistical analysis.

Results: : Fifty-two patients completed the 3-year study: 26 men and 26 women with a mean age of 76 +/- 6 years. CNV, confirmed with FA, developed in 23 (44%) of the 52 study eyes during the 3-year follow up (6 in the first year, 11 in the second and 6 in the third). One third of the eyes that developed CNV presented retinal angiomatosis proliferation (RAP). OCT was able to document the presence of intra or subretinal fluid at the time of conversion in all the 23 eyes. Large or intermediate drusens were present in 100% of the study eyes and hyperpigmentation in 85% (44 eyes). ICG drusens and/or hot spots were present in 20 (87%) of the eyes that developed CNV and in 18 (62%) of the eyes that did not develop CNV. Leakage in RLA was present in 17 (74%) of the eyes that developed CNV and in 12 (41%) of the eyes that did not. Patchy FAF pattern was present in 8 (35%) of the eyes that developed CNV and in 8 (28%) of the eyes that did not develop CNV. Only alterations in RLA and ICG represented risk to conversion (p<0,005 and p<0,001, respectively).

Conclusions: : In this 3-year follow-up study, development of CNV (RAP lesions in 33%) in fellow eyes of patients with unilateral exudative AMD, was higher than expected (44%). Only ICG and RLA were identified as good indicators of risk for development of CNV.

Clinical Trial: : http://www.clinicaltrials.gov NCT00902785

Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • neovascularization