Vitreous and iris neovascularization

Abstract

Until the 1940s, the growth of newly formed blood vessels into the vitreous was thought to be the consequence of vitreous hemorrhage, not its cause. The process appeared to represent “organization” (i.e., the invasion of a hematoma by macrophages, capillaries, and fibroblasts to form “granulation tissue”), eventually resulting a fibrous scar. However, serial examinations of eyes with “rete mirabile” (neovascular networks) and “retinitis proliferans” (fibrovascular membranes) showed that, except after severe trauma, neovascular invasion of the extracellular matrix invariably precedes vitreous hemorrhaging (Figure IV.C-1) [1]. Here, the evolution of theories of vitreous and iris neovascularization will be examined from within the perspectives of time and first-hand observations.