Development of retinal neovascularisation in vascular occlusive disease.
Retinal neovascularisation in 80 non-diabetic patients with occlusive retinal vascular disease appeared to be related at least as frequently to arterial as to venous occlusive disease. Intraretinal, preretinal and prepapillary neovascularisation had developed in 76 per cent, 47 per cent and 49 per cent respectively of the specimens. Neovascularisation in the adult retina is thought to develop in the following sequence of histopathologic features: plasmatic insudation and transudation of the vessel walls (100 per cent of the specimens), endothelial cell proliferation (97 per cent) and capillary formation (76 per cent). Intramural newly-formed capillaries in thickened hyalinized vessels were observed in 68 per cent of the specimens. Not only retinal vein occlusion but also slowly progressive arterial and arteriolar occlusive diseases may produce retinal neovascularisation, originating from arterioles, venules and capillaries which are involved in a hypoxic degenerative endothelial process which gives rise to endothelial proliferation.