OBJECTIVES:  To assess the real-world effectiveness and treatment patterns of ranibizumab and aflibercept for central retinal vein occlusion (CRVO) in the USA METHODS: Data were extracted from a panel of medical retina practices across the USA, using a standardized electronic medical record (EMR) system. Treatment-naïve adult patients were included if they had a CRVO diagnosis, ≥1 ranibizumab or aflibercept prescription between 01 July 2011 and 30 September 2014, and at least one year of follow-up. Eyes were excluded if they discontinued or switched anti-VEGF during the follow-up period. The primary endpoint was the mean (±standard deviation [SD]) change in best corrected visual acuity (BCVA) letter score from baseline to Month 12, compared between ranibizumab and aflibercept using generalized estimating equations, adjusting for baseline BCVA, age and for clustering at the patient-level. Mean number of injections and non-injection visits during the 12 months of follow-up were also compared. Eye was the unit of analysis. RESULTS: