Congenital retinal arterial loops with spontaneous vitreous hemorrhage.

A young adult demonstrated a spontaneous vitreous hemorrhage in an eye which harbored two retinal arterial loops, with bleeding originating in the area of the larger loop. These congenital vascular anomalies characteristically originate on the optic disk and terminate by anastomosing with or forming a retinal vessel. Although uncommon, congenital retinal arterial loops can no longer be thought innocuous and must be considered when decreased visual acuity occurs.