Movement of intraretinal fluid from distant branch retinal vein occlusion to the submacular space

BACKGROUND Extramacular branch retinal vein occlusion (BRVO) occasionally causes serous macular detachment. We studied the movement of extravasated fluid from BRVO lesions to the submacular space. METHODS We examined nine eyes from nine patients with serous retinal detachment caused by extramacular BRVO. In addition to a comprehensive ophthalmic examination, optical coherence tomography was performed in all nine eyes. Six of the patients also underwent fluorescein angiography. RESULTS Visual acuity ranged from 0.03 to 0.9 (median 0.5). All nine eyes showed localized macular detachment and retinal edema which extended from the extramacular BRVO to the macula. Fluorescein angiography revealed dye leakage in the extramacular area but no macular leakage in the six eyes examined. Optical coherence tomography revealed serous retinal detachment in the macula and intraretinal swelling, with low reflectivity in the outer retina extending from the distant BRVO toward the detached macula in all nine eyes. Six eyes were treated with laser photocoagulation, covering the entire area of BRVO, and the other three eyes were treated with intravitreal bevacizumab. Serous retinal detachment and retinal swelling resolved within 3 months of treatment in all nine eyes. CONCLUSION Distant retinal vascular leakage appears to diffuse through the outer retina to the macula, then permeate into the subretinal space.