Relationship between retinal volume changes and the prognosis of BRVO-ME treated with ranibizumab

This study aimed to evaluate the efficacy of ranibizumab for the treatment of macular edema secondary to branch retinal vein occlusion (BRVO-ME), changes in retinal volume and central retinal thickness (CRT) before and after therapy, and the connection between visual prognosis and changes in retinal volume.

The 120 patients(121 eyes) of BRVO-ME were recruited from July 2020 to October 2022 at the Affiliated Hospital of Weifang Medical University. The clinical data of patients were retrospectively examined for changes in best-corrected visual acuity (BCVA), retinal volume, and CRT at 1 day, 1 week, 1 month, 3 months, 6 months and 1year after treatment.

Visual acuity improved gradually and became steady approximately 1 months after treatment, whereas retinal volume decreased gradually in both the outer and full layers and stabilized around 6 month after treatment. The decline in retinal volume and CRT was more visible in the deeper layers than in the inner levels. A higher correlation was observed between retinal volume and BCVA than between CRT and BCVA. BCVA after one year of treatment had a high correlation with baseline outer retinal volume.

Treatment of BRVO-ME with ranibizumab is highly effective, and the recovery of visual function was depends more on early treatment. The outer retina is the major site of edema. Changes in retinal volume may serve as a better predictor of visual prognosis than changes in CRT. Baseline ourter retinal volume is correlated with long-term visual prognosis.