Baseline Choroidal Blood Flow Imbalance as a Predictive Factor for Macular Edema Recurrence Secondary to Branch Retinal Vein Occlusion

Abstract

Background/Objectives: To evaluate the roles of choroidal blood flow (CBF) and choroidal thickness (CT) as predictors of macular edema recurrence in patients with treatment-naive non-ischemic branch retinal vein occlusion (BRVO) after intravitreal ranibizumab (IVR) injection. Methods: Sixteen eyes from sixteen patients with treatment-naive non-ischemic BRVO treated with IVR, once initially and then as needed, were included in the study. CBF and CT in the subfovea, occlusive, and non-occlusive regions were measured via laser speckle flowgraphy and enhanced depth imaging optical coherence tomography over 12 months. Results: Baseline CT was significantly greater in the occlusive region (335 ± 72.1 µm) than in the non-occlusive region (274 ± 36.7 µm, p = 0.028). CT in the occlusive region was reduced significantly after 1 week (p = 0.008), but CBF did not change significantly after IVR throughout the follow-up period (p > 0.05). The occlusive/non-occlusive region CBF ratio at baseline was significantly associated with the number of IVR injections over 12 months (mean 2.63) in patients with BRVO (p = 0.048). Conclusions: Baseline CBF imbalance in eyes with treatment-naive BRVO may indicate the recurrence of macular edema after ranibizumab therapy.

Keywords

• laser speckle flowgraphy
• branch retinal vein occlusion
• macular edema
• anti-VEGF drugs
• choroidal blood flow
• choroidal thickness