Association Between Cilioretinal Arteries and Advanced Age-Related Macular Degeneration: Secondary Analysis of the Comparison of Age-Related Macular Degeneration Treatment Trials (CATT)

IMPORTANCE: Recent reports suggest that cilioretinal arteries (CRAs) confer protection against developing advanced age-related macular degeneration (AMD). OBJECTIVE: To further characterize the association between the presence of a CRA and incidence of geographic atrophy (GA) or choroidal neovascularization (CNV). DESIGN: This cohort study constituted an ad hoc secondary analysis of data from the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT) and was performed at 44 clinical centers in the United States among participants in CATT with CNV in the study eye and without advanced AMD in the fellow eye at baseline. The presence of a CRA was determined by 2 graders, masked to clinical data, using color fundus photographs, red-free fundus photographs, and fluorescein angiography. The proportion with CRAs at baseline between the study eye with CNV and fellow eye without CNV was first compared. The association of a CRA with incidence of CNV or GA at 5 years among fellow eyes and with incidence of GA among study (treated) eyes was then assessed. In addition, the association of CRAs with the Age-Related Eye Disease Study severity scale among the fellow eyes at baseline was assessed. Data were collected from February 1, 2008, through April 30, 2015, and analyzed from July 1, 2018, through April 30, 2019. EXPOSURES: Presence of a CRA. MAIN OUTCOMES AND MEASURES: The association between the presence of a CRA and incidence of CNV or GA at 5 years of follow-up. RESULTS: A total of 350 patients (700 eyes) (230 [65.7% women; mean [SD] age, 77 [7.2] years) were included in the analysis. Cilioretinal arteries were present in 67 of 345 (19.4%) fellow eyes without baseline CNV and 73 of 349 (20.9%) study eyes with baseline CNV (P = .60). Cilioretinal arteries in fellow eyes were not associated with incidence of CNV at 5 years (125 of 278 [45.0%] among eyes without CRAs and 30 of 67 [44.8%] among eyes with CRAs; P = .99) or with incidence of GA at 5 years (110 of 278 [39.6%] among eyes without CRAs and 25 of 67 [37.3%] among eyes with CRAs; P = .89). Cilioretinal arteries in study eyes were not associated with incidence of GA at 5 years (105 of 276 [38.0%] study eyes without CRAs and 26 of 73 [35.6%] study eyes with CRAs; P = .72). CONCLUSIONS AND RELEVANCE: The analysis did not find a protective association between CRAs and incidence of CNV or GA among CATT participants who had unilateral exudative AMD. Why these findings were different from those of pr