[Pathogenesis of retinopathy of prematurity]

Retinopathy of prematurity (ROP) is a vascular disease of the eye unique to preterm infants. The distinctive feature of ROP is that is an illness of the still-maturing organism. Thus, an understanding of the normal fetal development of the retina is fundamental to understanding the pathogenesis of ROP. Animal models of ROP differ in important attributes, a fact that is important for interpretation of results. However, all models have in common the finding that ROP is a biphasic disease. In the first phase, relative hyperoxia results in vaso-obliteration and vessel loss. The second phase is characterized by hypoxia-induced neovascularization resulting in retinal detachment and blindness. Oxygen-dependent vascular endothelial growth factor (VEGF) and oxygen-independent insulin-like growth factor (IGF-1) have been identified as important factors in the pathogenesis of ROP. These findings suggest new therapeutic approaches. Substitution of IGF-1 during the first phase of the disease may help prevent vessel loss, and administration of anti-angiogenic substances during the second phase may prevent pathological neovascularization.