Correlation between short- and long-term effects of intravitreal ranibizumab therapy on macular edema after branch retinal vein occlusion: a prospective observational study

BACKGROUND The correlation between the short- and long-term effects of intravitreal ranibizumab (IVR) on macular edema after branch retinal vein occlusion (BRVO) remains unclear. We assessed the correlation between the short- and long-term effects of IVR on macular edema after BRVO. METHODS Twenty-one eyes with macular edema after BRVO were enrolled in this prospective observational study. We measured the foveal thickness (FT) and the best-corrected visual acuity (BCVA) before, 1 day after, and 1 month after IVR (0.5 mg) and then at least every 2 months thereafter until 6 months after the injection. If the macular edema recurred, another injection was administered. The primary endpoint was the change from baseline in the BCVA (ΔVA). RESULTS The mean logarithm of the minimum angle of resolution VA improved significantly (p = 0.01, p < 0.0001, respectively) after 1 day from 0.65 ± 0.28 to 0.51 ± 0.21 (20/89 to 20/63, Snellen equivalent) and after 6 months to 0.29 ± 0.24 (20/39, Snellen equivalent). The mean FT decreased significantly (p < 0.0001) after 1 day from 482 ± 85 μm to 349 ± 75 μm and after 6 months to 305 ± 84 μm. The 1-day VA was significantly (r = 0.68, p = 0.0007) positively correlated with the 6-month VA. The 1-day ΔVA was significantly (r = 0.79, p < 0.0001) positively correlated with the 6-month ΔVA. CONCLUSIONS The short-term effects of IVR may predict the long-term effects of IVR in macular edema secondary to BRVO. TRIAL REGISTRATION Trial registration number: UMIN000027003 . Retrospectively registered. (April/15/2017).