To determine the relationship between delayed patchy choroidal filling and morphologic and functional outcomes among eyes treated with ranibizumab or bevacizumab.

Cohort study.

Comparison of Age-related Macular Degeneration Treatment Trials participants were assigned randomly to ranibizumab or bevacizumab on a monthly or as-needed schedule. Presence of delayed patchy choroidal filling and morphologic and functional outcomes were evaluated among eyes with gradable fluorescein angiography at baseline (n = 973) and at 1 year (n = 860) eyes.

Delayed filling was present in 75 (7.7%) of 973 eyes at baseline. Eyes with incident delayed filling at 1 year (23 [2.9%] of 798) showed a mean decrease of 1.7 letters in visual acuity, whereas eyes without incident delayed filling had a mean improvement of 8.1 letters (difference [Δ], −9.8; 95% confidence interval [CI] , −15.8 to −3.9; P < .01). Eyes with incident delayed filling had a larger increase in mean total lesion area of choroidal neovascularization (3.00 mm²) than eyes without incident delayed filling (0.56 mm²; Δ , 2.4; 95% CI, 0.4 to 4.4; P = .02). The proportion with incident delayed filling at 1 year was similar among eyes treated with ranibizumab (10 [2.4%] of 413) or bevacizumab (13 [3.3%] of 385; P = .53) and among eyes treated monthly (12 [3.1%] of 388) or as needed (11 [2.7%] of 410; P = .83).

Delayed patchy choroidal filling was uncommon at baseline. Although only a small percentage of eyes demonstrated delayed filling during the first year of anti–vascular endothelial growth factor treatment, these eyes had worse visual acuity and a larger increase in total lesion area of choroidal neovascularization.