• Nine family members with hereditary retinal neovascularization showed wide variability in the extent of the clinical disorder and a slow progression of the disease process. Clinical and angiographic evaluation of these patients at various stages of their disease, and analysis of their histories points to a progressive peripheral retinal vascular disorder with secondary vitreous changes. The condition is characterized by retinal arteriolar ischemia, new vessel formation at the retinal periphery, and hemorrhage with retinal detachment.