Branch retinal vein occlusion: natural history of visual outcome.

IMPORTANCE Understanding the natural history of visual outcome in branch retinal vein occlusion (BRVO) is fundamental to its management. OBJECTIVE To investigate the natural history of visual outcome in major and macular BRVO. DESIGN, SETTING, AND PARTICIPANTS Observational cohort study at a university-based referral practice from 1973 until 1999. The study comprised 216 consecutive eyes with BRVO (144 eyes with major and 72 eyes with macular BRVO) seen within 3 months of onset. INTERVENTION At first visit, all patients had a detailed ophthalmic and medical history and comprehensive ophthalmic evaluation. Ophthalmic evaluation at initial and follow-up visits included recording best-corrected visual acuity (VA) using the Snellen VA chart and visual fields with a Goldmann perimeter. MAIN OUTCOMES AND MEASURES Best-corrected VA and visual field outcome on follow-up. RESULTS The median time to macular edema resolution was 21 months in those with major BRVO and 18 months in those with macular BRVO. Overall, for eyes with initial VA of 20/60 or better, VA improved or remained stable in 75% (95% CI, 63%-86%) for major BRVO and 86% (95% CI, 73%-95%) for macular BRVO. In those with initial VA of 20/70 or worse, VA improved in 69% (95% CI, 56%-80%) for major BRVO and in 53% (95% CI, 27%-79%) for macular BRVO, with median final VA of 20/60 for both BRVO types. CONCLUSIONS AND RELEVANCE Major and macular BRVOs are 2 distinct clinical entities, and initial visual status and final visual outcome in the 2 types are quite different. Overall, on resolution of macular edema, our study suggests that in both major and macular BRVO, VA and visual fields improved to a variable degree in the majority of eyes without any treatment.