Switching anti-VEGF agents does not improve visual outcomes in branch retinal vein occlusion-related macular edema

Background: Branch retinal vein occlusion (BRVO) frequently results in macular edema (ME), impairing visual acuity (VA). Intravitreal anti-vascular endothelial growth factor (VEGF) injections are standard first-line therapy but the benefit of switching agents (Ranibizumab or Aflibercept) is unclear. This study evaluated VA and treatment burden after switching anti-VEGF agents for persistent ME secondary to BRVO. Methods: This retrospective cohort study included patients with ME due to BRVO treated at a tertiary referral clinic between August 2015 and December 2022. All received ≥ 3 monthly Bevacizumab injections; those with < 10% or < 50 µm reduction in central retinal thickness on optical coherence tomography (OCT) were eligible to switch to Ranibizumab or Aflibercept. Patients were grouped into “No-switch” or “Switch”. VA and injection frequency were assessed over 36 months using linear mixed-models. Results: Of 385 eyes, 251 (65.2%) remained on Bevacizumab and 134 (34.8%) switched (71 Ranibizumab, 63 Aflibercept). VA significantly improved in both groups (p < 0.001), with no between-group difference (p = 0.897). In the Switch group, VA improved initially but showed no further gains post-switch and remained stable through 36 months (pre-switch 66.43 ± 12.99 and 67.34 ± 14.76 at 36 months, p = 0.144). Switching increased injection frequency in years 1–2 (p < 0.001 for both), but not year 3 (p = 0.207), and no difference between Ranibizumab and Aflibercept (p = 0.331). Conclusion: Switching anti-VEGF agents in BRVO-related ME did not improve VA but increased injection burden. VA stability before and after switching suggests no rescue effect, though anatomical stabilization may have contributed to long-term preservation.