Retinal neovascularisation arising from hyalinised blood vessels.

In a retrospective histopathological study of 75 eyes with occlusive retinal vascular disease, intraretinal, preretinal and prepapillary neovascularisation was observed in 76%, 48% and 48%, respectively. The central retinal vein, artery and branch arteries were shown to be occluded in 48, 46 and 6 cases, respectively. Generalised obliterative arteriolovenular sclerosis was observed on 24 occasions; combined stem occlusions of the central retinal vein and artery was found in 33 specimens. A most significant finding was the presence of intramural capillaries within hyalinised retinal vessels in 51 cases (68%). These newly formed capillaries originated from proliferating vascular endothelium; their lumina communicated with the vascular lumen and continued in many instances into congeries of newly formed intra- and preretinal capillaries. The diseased parent vessels showed evidence of plasmatic insudation and transudation (100%) and endothelial proliferation (97%). These phenomena constitute the first stage of a type of retinal neovascularisation which has not hitherto been adequately described.