ABSTRACT: Importance:Two-year outcomes are reported comparing eyes originally assigned to aflibercept or bevacizumab to assess the need for continued anti-vascular endothelial growth factor (VEGF) therapy for macular edema due to central retinal vein occlusion (CRVO) or hemiretinal vein occlusion (HRVO) from participants in the Study of Comparative Treatments for Retinal Vein Occlusion 2 (SCORE2) trial. Objective:To investigate outcomes 1 year after cessation of the SCORE2 treatment schedule. Design, Setting, and Participants:In this secondary analysis of the SCORE2 randomized clinical trial, follow-up included 117 participants originally randomized to aflibercept and 119 participants originally randomized to bevacizumab between September 17, 2014, and November 18, 2015. Data for the analyses were frozen on September 13, 2018. Interventions:SCORE2 participants completed the treatment protocol at month 12, were subsequently treated at investigator discretion, and underwent assessment at month 24. Main Outcomes and Measures:Visual acuity letter score (VALS) and central subfield thickness (CST) on spectral-domain optical coherence tomography. Results:Among 362 participants randomized to aflibercept or bevacizumab, 65.2% (236 of 362) completed a protocol visit at month 24 (mean [SD] age, 68.5 (12.0) years; 53.8% male). The mean (SD) VALS improved from baseline to 12 months by 21.6 (14.5) in the aflibercept group compared with 21.9 (16.6) in the bevacizumab group (difference, -0.3; 99% CI, -5.6 to 4.9), then worsened from those values by a mean (SD) VALS of 7.6 (17.5) in the aflibercept group and 7.5 (14.5) in the bevacizumab group (difference, -0.1; 99% CI, -5.6 to 5.3) at month 24. The mean (SD) CST improved from baseline to 12 months by 394 (231) ?m in the aflibercept group compared with 420 (274) ?m in the bevacizumab group (difference, 26 ?m; 99% CI, -62 to 114 ?m), then worsened from those values by a mean (SD) of 58 (192) ?m in the aflibercept group compared with 48 (186) ?m in the bevacizumab group (difference, 10 ?m; 99% CI, -58 to 78 ?m) at month 24. Conclusions and Relevance:No differences in VALS or CST outcomes at month 24 were identified when participants originally assigned to aflibercept were compared with those assigned to bevacizumab. Caution in interpretation is needed because of loss to follow-up. In both groups, VALS and CST improved through month 12 and then worsened somewhat during the second year, when treatment was at investigator discretion. This analysis suggests that CRVO and HRVO warrant close monitoring and treatment as needed over at least 2 years to optimize outcomes in eyes treated with anti-VEGF therapy. Trial Registration:ClinicalTrials.gov identifier: NCT01969708.