Retinal neovascularization after retinal vaso-obliteration. Frequency--origin--morphology.

Retinal neovascularization (NV) was found microscopically in 76% of 74 eyes with neovascular glaucoma after retinal vaso-obliteration, and in 75% or more of eyes with any type of retinal vascular occlusive disease. Preretinal NV was encountered in 47% and prepapillary NV in 49%. Retinal arterial occlusive disease was more often an underlying condition (81%) than retinal venous occlusive disease (49%). Morphological stages of retinal NV in adults are (1) insudation and/or transudation of vessel walls (100%) with endothelial proliferation (97%) and (2) capillary formation (76%). The latter takes place via intramural capillaries (31%) and endothelial plexuses (24%), and from pre-existent capillaries. New capillaries arise from arterioles, venules and capillaries. Hyalinization can be found in any retinal vessel type. Retinal NV is primarily induced by retinal hypoxia.