The 'Loss of Peak Vision' in Branch Retinal Vein Occlusion: Real-World Implications for Stratified Intervention.

Purpose Branch retinal vein occlusion (BRVO) is the second most common retinal vascular disorder. This study evaluates the real-world visual and anatomical outcomes of intravitreal aflibercept in BRVO, addressing the gap between clinical trials and daily practice, and aims to identify distinct response phenotypes that predict functional decline. Methods This retrospective analysis included 96 BRVO patients receiving aflibercept monotherapy over 12 months. Patients were stratified into three groups based on anatomical response: Resolved (sustained dry macula), Recurrent (fluid recurrence after initial resolution), and Persistent (incomplete resolution). The primary outcome was change in best-corrected visual acuity (BCVA). Results At 12 months, eyes were Resolved (52%), Recurrent (27%), or Persistent (21%). The Resolved group achieved the best visual outcomes (-0.29 logMAR; 95% CI, -0.38 to -0.20), whereas the Recurrent group showed the least improvement (-0.05 logMAR; 95% CI, -0.22 to 0.12; p=0.021 vs. Resolved). Despite achieving complete fluid resolution at month 3, this group experienced significant rebound by month 6. Total injections (p=0.808) and the distribution of treatment strategies did not differ among groups. Baseline BCVA (β=0.411, 95% CI: 0.202 to 0.619; p=0.001) and treat-and-extend (T&E) regimen (β=0.244, 95% CI: 0.033 to 0.454; p=0.025) significantly predicted visual improvement, whereas baseline central macular thickness (CMT) and systemic factors were not. Conclusion In a real-world setting, nearly half of BRVO patients exhibit unstable phenotypes. Despite comparable treatment intensity, cumulative damage from fluid fluctuations causes irreversible visual loss in the Recurrent group. This supports a stratified intervention strategy: evaluating month-3 response to establish strict T&E intervals or early treatment modifications, mitigating preventable vision loss.