Differences in long-term progression of atrophy between neovascular and non-neovascular age-related macular degeneration

Purpose: To compare the enlargement rates of geographic atrophy (GA) over 5 years of follow-up with those of macular atrophy (MA) associated with macular neovascularization (MNV). Design: Retrospective, longitudinal, comparative case series. Participants: Consecutive series of patients with age-related macular degeneration and GA (dry) or with MA and MNV. Methods: Atrophic regions detected on serial registered fundus autofluorescence images were semiautomatically delineated, and the measurements of these areas were recorded every 6 ± 3 months for the first 2 years of follow-up and at yearly intervals for up to 5 years. Main Outcome Measures: Annual raw and square root-transformed rates of atrophy growth. Results: The study included 117 eyes of 95 patients (61 in the GA cohort and 56 in the MA cohort); 100% and 38.5% of the eyes completed 2 and 5 years of follow-up, respectively. The mean size of lesions at baseline was similar between the 2 groups (raw: 1.74 vs. 1.53 mm2, P = 0.56; square root-transformed: 1.17 vs. 1.02 mm, P = 0.26). The overall enlargement rates were greater for the GA cohort (raw: 1.72 vs. 1.32 mm2/year, P = 0.002; square root-transformed: 0.41 vs. 0.33 mm/year, P = 0.03), and so was the area of atrophy growth at 5 years (raw: +8.06 vs. +4.55 mm2, P = 0.001; square root-transformed: +1.93 vs. +1.38 mm, P = 0.02). The estimated square root-transformed area was also significantly greater for the GA cohort at 2 years (1.84 vs. 1.67 mm, P = 0.01). Conclusions: The presence of MNV was associated with a slower rate of expansion, resulting in overall smaller areas of atrophy over time. These findings support the hypothesis that MNV may protect against the progression of atrophy.