Contributor: Gordon K. Klintworth
Retinal neovascularization develops in numerous retinopathies associated with retinal ischemia, such as sickle cell retinopathy [retinopathy - sickle cell], Eales disease, ocular ischemic syndrome, carotid cavernous fistula, familial exudative vitreoretinopathy, a hyperviscosity syndrome, idiopathic occlusive arteriolitis, proliferative diabetic retinopathy [diabetic retinopathy - proliferative], radiation retinopathy, retinal vein occlusion, retinal artery occlusion, retinal embolism, retinopathy of prematurity). Retinal neovascularization can also occur with inflammatory diseases (birdshot retinochoroidopathy, retinal vasculitis, sarcoidosis, toxoplasmosis, and uveitis) a choroidal melanoma [melanoma - choroid], chronic retinal detachment, incontinentia pigmenti, and rarely in retinitis pigmentosa.
A factor common to almost all retinal 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. Retinal neovascularization commonly progresses to vitreoretinal neovascularization [neovascularization - vitreoretinal]. Iris neovasularization [neovascularization - iris] and neovascular glaucoma [glaucoma - neovascular] often follow retinal neovascularization.