ASRS 2026: Margaret Chang, MD, MS, on baseline predictors of vision loss in geographic atrophy

Margaret Chang, MD, MS, a senior partner at Retinal Consultants Medical Group in Sacramento, California, discussed new baseline predictors of vision loss from the phase 2 ARCHER study of vonaprument in geographic atrophy (GA) secondary to age-related macular degeneration (AMD) at the American Society of Retina Specialists (ASRS) 44th Annual Scientific Meeting, held July 15–18, 2026, in Montréal, Québec, Canada.

Chang explained that although GA lesion size measured by fundus autofluorescence was the primary end point of the phase 2 ARCHER trial, secondary functional measures, including best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA), proved especially meaningful to patients. In a post hoc analysis of baseline characteristics, she and colleagues found that eyes with baseline visual acuity between roughly 20/40 and 20/100, as well as eyes with subfoveal rather than extrafoveal lesions, were most likely to experience a loss of 15 or more ETDRS letters through 12 months. Baseline age and lesion size were not associated with this degree of vision loss, nor were any other ocular or medical history factors the investigators evaluated.

Chang said these findings carry direct implications for patient counseling. Eyes with better baseline acuity than 20/40 are more likely to preserve vision over the following year, while eyes worse than 20/100 tend to remain relatively stable, offering reassurance for patients at both ends of the spectrum. She noted the results also helped shape enrollment criteria for the ongoing phase 3 ARCHER II trial.

Chang also addressed the field's broader shift toward functional, patient-centered outcomes in GA research. She said regulatory agencies, including the European Medicines Agency, increasingly expect functional data before approving GA complement therapies, and that the threat of vision loss in GA is more immediate than previously assumed. Asked about unmet needs, Chang said the field still lacks reliable functional outcome measures, noting that BCVA alone is not the most reliable indicator of how patients actually function day to day. She also pointed to artificial intelligence as a promising tool for projecting lesion progression, correlating anatomic change with vision, and supporting patient selection for future GA trials.