IGF1 and retinopathy of prematurity: ROP is a vasoproliferative disease of the retina that affects preterm infants and consists of 2 phases: (1) disruption of retinal vessel formation, and (2) abnormal retinal neovascularization.[1,2] Angiogenesis is an important process in the development of ROP,[1] involving various angiogenic and growth factors.[3–5] In particular, it is well established that the interaction between vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 is important in regulating retinal vascular development during the postnatal period.[3–5]