- Proliferation of blood vessel s in tissue not normally containing them, or proliferation of blood vessel s of a different kind than usual in tissue.- choroidal n. ingrowth of new vessels from the choriocapillaris into the subretinal pigment epithelium and the retina; space associated with damage to the outer retina.- classic choroidal n. well-demarcated areas of hyperfluorescence observed in the early phases of a retinal angiogram.- occult choroidal n. area of leakage of undetermined source seen in the late phases of a retinal angiogram.- Type 1 choroidal n. ingrowth of new vessels from the choriocapillaris into the subretinal pigment epithelial space; associated with damage to the outer retina.- Type 2 choroidal n. ingrowth of new vessels from the choriocapillaris into the subretinal space; associated with damage to the outer retina.
* * *neo·vas·cu·lar·i·za·tion also Brit neo·vas·cu·lar·i·sa·tion -.vas-kyə-lə-rə-'zā-shən n vascularization esp. in abnormal quantity (as in some conditions of the retina) or in abnormal tissue (as a tumor)
* * *n.the abnormal formation of new and fragile blood vessels, usually in response to ischaemia. In choroidal neovascularization, which occurs in such conditions as macular degeneration and diabetic retinopathy, abnormal vessels, derived from the choroid, form a choroidal neovascular membrane in the space below the retinal pigment epithelium (see retina).
* * *neo·vas·cu·lar·iza·tion (ne″o-vas″ku-lər-ĭ-zaґshən) 1. new blood vessel formation in abnormal tissue or in abnormal positions. 2. revascularization. Cf. angiogenesis (def. 2).
Neovascularization on the optic disk (arrow) in a patient with proliferative diabetic retinopathy.
Medical dictionary. 2011.