Differences in Long-Term Progression of Atrophy between Neovascular and Nonneovascular 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.