Abstract:Retinopathy of prematurity(ROP)is a leading cause of childhood blindness, with extremely preterm and very-low-birth-weight infants now constituting the main high-risk group. ROP progresses in two stages: early retinal microvascular degeneration and progressive vascular arrest, followed by abnormal neovascularization in the avascular area. Early oxidative and nitrosative stress—amplified by oxygen fluctuations and immature antioxidant defenses—drives the two-phase pathogenesis via hypoxia-inducible factor/vascular endothelial growth factor(HIF/VEGF), NOX/STAT3, and nuclear factor erythroid 2 related factor 2(Nrf2)-antioxidant response element(ARE)pathways, mediating apoptosis of endothelial cells, damage to barrier and pathological angiogenesis. This review systematically analyzes different oxygen-induced retinopathy(OIR)models, elucidates key signaling pathways including Notch, Wnt in physiological and pathological vascularization, with particular emphasis on the biphasic effects of Nrf2 and the differential roles of NOX signaling between phases. We also discuss the limitations of anti-VEGF therapy and oxygen management principles. Reactive oxygen species(ROS)play context-dependent roles across vaso-obliteration and neovascularization phases. Based on mechanistic insights, we propose future directions including combined/sequential interventions, ferroptosis and lipid peroxidation targeting, nano-delivery systems for enhanced bioavailability, and perinatal safety assessment strategies, aiming to provide translatable mechanistic basis for reducing pathological neovascularization while promoting physiological vascular development.
