Progression of Geographic Atrophy with Subsequent Exudative Neovascular Disease in Age-Related Macular Degeneration: AREDS2 Report 24.

Purpose: To examine whether the rate of geographic atrophy (GA) enlargement is influenced by subsequent exudative neovascular age-related macular degeneration (nAMD) and hence, to explore indirectly whether nonexudative nAMD may slow GA enlargement.

Design: Post hoc analysis of a controlled clinical trial cohort.

Participants: Age-Related Eye Disease Study 2 participants 50 to 85 years of age.

Methods: Baseline and annual stereoscopic color fundus photographs were evaluated for (1) GA presence and area and (2) exudative nAMD presence. Two cohorts were constructed: eyes with GA at study baseline (prevalent cohort) and eyes in which GA developed during follow-up (incident cohort). Mixed-model regression of the square root of GA area was performed according to the presence or absence of subsequent exudative nAMD.

Main Outcome Measures: Change over time in square root of GA area.

Results: Of the 757 eyes in the incident GA cohort, over a mean follow-up of 2.3 years (standard deviation [SD], 1.2 years), 73 eyes (9.6%) demonstrated subsequent exudative nAMD. Geographic atrophy enlargement in these eyes was significantly slower (0.20 mm/year; 95% confidence interval [CI], 0.12-0.28 mm/year) compared with the other 684 eyes in which subsequent exudative nAMD did not develop (0.29 mm/year; 95% CI, 0.27-0.30 mm/year; P = 0.037). Of the 456 eyes in the prevalent GA cohort, over a mean follow-up of 4.1 years (SD, 1.4 years), 63 eyes (13.8%) demonstrated subsequent exudative nAMD. Geographic atrophy enlargement in these eyes was similar (0.31 mm/year; 95% CI, 0.24-0.37 mm/year) compared with the other 393 eyes in which subsequent exudative nAMD did not develop (0.28 mm/year; 95% CI, 0.26-0.29 mm/year; P = 0.37).

Conclusions: In eyes with recent GA, GA enlargement before the development of exudative nAMD seems slowed. This association was not observed in eyes with more long-standing GA, which have larger lesion sizes. Hence, perilesional nonexudative choroidal neovascular tissue (presumably present before the development of clinically apparent exudation) may slow enlargement of smaller GA lesions through improved perfusion. This hypothesis warrants further evaluation in prospective studies.