CONGENITAL ARTERIOVENOUS (RACEMOSE) ANEURYSM OF THE RETINA: Report of Three Cases

CONGENITAL arteriovenous aneurysm of the retina is a developmental anomaly of rare occurrence. The complexity of the retinal changes varies greatly, as does the symptomatology. The essential feature of the ophthalmoscopic picture is a communication between an artery and a vein. This may be duplicated a number of times, with pronounced dilatation of the intervening capillary system. A great increase in the size, shape, number, and tortuosity of the retinal blood vessels may also be encountered. It is impossible in many cases to decide where the dividing line between vein and artery should be drawn. Frequently it is difficult to ascertain whether a vessel is an artery or a vein. The visual acuity is often severely reduced but may be normal. In general there is no progression of the anomaly. Involvement of the retinal vessels alone, without vascular malformation elsewhere, may occur. The possibility of coexistent arteriovenous aneurysm or vascular