To determine whether early visual acuity response to intravitreal bevacizumab in macular edema (ME) secondary to branch retinal vein occlusion (BRVO) is associated with 12-month follow-up outcome.

Sixty treatment-naïve patients (60 eyes) with ME secondary to BRVO treated with intravitreal bevacizumab (1.25 mg) were retrospectively included. Initially, all patients were injected monthly to achieve fluid resolution and followed up with a pro re nata regimen for at least 12 months. The relationship between early (month 1) and late (month 12) visual acuity response (mean change from baseline in best-corrected visual acuity [BCVA]; categorized improvement [<1, 1–3, or ≥3 logMAR lines in BCVA]) was explored.

The proportions of eyes with <1, 1-<3, and ≥3-line improvements at 1 month were 19 eyes (31.7%), 17 eyes (28.3%), and 24 eyes (40%), respectively. Within each of the three response categories, the mean BCVA change from baseline at 12 months and onward did not vary by more than 1 line from the observed mean BCVA improvement at 1 month. Inter-cohort differences across the three response categories in mean BCVA change from baseline were statistically significant at each time point. Early BCVA response at 1 month showed significant associations with ≥3 line improvement and BCVA response at 12 months in multiple logistic and linear regression analyses.

Early BCVA responses to bevacizumab are associated with subsequent responses over the entire 12-month duration of treatment.