Increased fundus autofluorescence and progression of geographic atrophy secondary to age-related macular degeneration. The GAIN study.

Purpose To define the role of increased fundus autofluorescence (FAF), a surrogate for lipofuscin content, as a risk factor for progression of geographic atrophy (GA). Design Prospective natural history cohort study, the GAIN (Characterization of geographic atrophy progression in patients with age-related macular degeneration). Methods setting: Single-center study conducted in Barcelona, Spain. patients: After screening of 211 patients, 109 eyes of 82 patients with GA secondary to age-related macular degeneration and a minimum follow-up of 6 months were included. observation procedures: Lipofuscin content was classified independently by 2 masked observers according to FAF patterns described previously. Bivariate, stratified, and multivariable analyses were used to explore the associations between GA growth and independent variables. Mediation analysis was used to evaluate the contribution of FAF patterns to GA progression. main outcome: Progression of GA in mm 2 /year as measured with FAF. Results Median follow-up was 18 months (range, 6–42). Median GA growth was 1.61 mm 2 /year. FAF, baseline area of atrophy, and time of follow-up were independently associated with GA progression ( P P Conclusions FAF patterns, baseline area of atrophy, and time of follow-up were associated with GA progression. However, FAF patterns seem to be a consequence (not a cause) of enlarging atrophy and their effect on GA progression seems mostly driven by baseline area of atrophy.