Purpose: To determine the choroidal blood flow and subfoveal choroidal thickness (SCT) in eyes with macular edema secondary to branch retinal vein occlusion (BRVO).
Methods: Thirty-two eyes of 32 patients with macular edema secondary to a BRVO were treated with a single intravitreal injection of ranibizumab (IVR) and were followed for 2 months. The central retinal thickness and SCT, and the retinal and choroidal blood flows were evaluated, and they were compared between the recurrent and resolved groups.
Results: At the baseline, the SCT of eyes with a BRVO was significantly thicker than that of the fellow eye (P < 0.01). It was also significantly thicker in the recurrent group than in the resolved group (P = 0.03). The reduction of the retinal blood flow was found only after 1 week in the resolved group. The SCT and choroidal blood flow were significantly reduced during the follow-up period in the resolved group but not in the recurrent group.
Conclusion: The choroid is involved in the pathology of BRVO and the SCT at the baseline may be a predictive factor in the treatment of intravitreal injection of ranibizumab for macular edema secondary to BRVO.