Vascular Endothelial Growth Factor and the Eye: Past, Present, and Future

Vascularization within the eye is a fundamental process involved not only in normal ocular development but also in a wide range of ophthalmic diseases. Such seemingly disparate clinical entities as diabetic retinopathy, central retinal vein occlusion, retinopathy of prematurity (ROP), age-related macular degeneration, sickle cell retinopathy, radiation retinopathy, and Eales disease may all eventually lead to uncontrolled vascularization. The potential role of growth factors as mediators of developmental and pathologic intraocular vascularization has been recognized for almost half a century, since the release of an angiogenic factor by the retina was first proposed by Michaelson¹ in 1948.² Subsequently, an extensive search for molecules with the diverse attributes required to account for the clinical observations associated with all of these conditions has been conducted.³ Fibroblast growth factors, insulinlike growth factors, and growth hormone have been evaluated, and, although each has demonstrated interesting associations with clinical disease and potential