Proliferation of retinal blood vessels is one of the most striking features of advanced diabetic retinopathy. This feature has led to the conclusion that the normal balance of growth factors, which usually serves to keep angiogenesis in check, is disturbed in diabetic retinopathy. A considerable amount of work has been performed in the field of angiogenesis within the last decade. Much of this is applicable to diabetic eye disease, but due to the lack of an animal model, few studies have been performed directly on models of diabetic retinopathy. This review examines the literature as it relates to diabetic retinopathy.