Introductory comments for session V "neovasculogenesis" presented at the fifth symposium, the International Society on Metabolic Eye Disease October 24-26, 1982.

Physiopathologic or metabolic alterations in retinal blood vessels resulting in an ischemic state may be a prime trigger mechanism in neovasculogenesis and scar tissue formation. Rate of oxygen delivery may be the primary factor so the end-state disease may be rapid as in retrolental fibroplasia (marked reduction in vascular flow due to acute vasoconstriction) or delayed as in diabetes mellitus (chronic metabolism-induced low oxygen release rates parallel with chronic vasodilation).