Spontaneous retinal-choroidal anastomosis in a case of branch retinal vein occlusion

PURPOSE: To report a case of a patient affected by branch retinal vein occlusion (BRVO) showing a possible spontaneous retinal-choroidal anastomosis (RCA) at the level of the fovea. OBSERVATIONS: A 72 years old male patient with diagnosis of BRVO of left eye (LE) one year before came to our observation for a follow-up visit. The patient underwent a complete ophthalmologic examination, including fluorescein angiography, structural optical coherence tomography (OCT), OCT-Angiography (OCT-A). Interestingly, OCT-A revealed the presence of blood flow suggestive of single collateral vessel descending from the deep capillary plexus up to and possibly below a hyperreflective subfoveal deposit. CONCLUSIONS AND IMPORTANCE: We hypothesize that it can represent a RCA, starting from retinal capillaries and reaching the choriocapillary and choroidal vessels in order to allow a vascular shunt between the 2 circulations and thus a new passage for the blood flow. A similar condition is represented by laser-induced RCA for the treatment of non-ischemic central retinal vein occlusion in order to establish a new passage for the blood flow.