Retinal arterio-venous communications

Arterio-venous retinal communications are congenital anastomoses between a vein and an artery in the retina. Such anastomoses are rare and are classified in 3 groups depending on whether or not there is an abnormal network of capillaries between the arteries and the veins. Classification also depends on the diameter of the anastomosed vessels. In a few, very rare, cases, the most severe arterio-venous communications may be associated with malformations in cerebral vascularisation.