Contributor: Gordon K. Klintworth
Vitreoretinal neovascularization develops in numerous retinal diseases (proliferative diabetic retinopathy [diabetic retinopathy - proliferative], retinopathy of prematurity, central retinal vein occlusion, sickle cell retinopathy [retinopathy - sickle cell], Eales disease, and other retinopathies associated with retinal ischemia). A factor common to almost all vitreoretinal neovascularization is retinal ischemia, which is thought to release diffusible angiogenic factors (such as VEGF). The neovascularization begins within the retina and then breaches the retinal internal limiting membrane. The new vessels grow on the inner retina and the posterior surface of the vitreous after it has detached [vitreous detachment]. Neovascularization may erupt from the surface of the optic disk or the retina. Non-oxygen-induced vitreoretinal  neovascularization occurs in  anencephaly, hydranencephaly, and Potter syndrome.