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.

Objective To evaluate the clinical efficacy and safety of catheter ablation for atrial fibrillation in elderly patients.Methods From September 2008 to October 2011,a total of 420 consecutive patients undergoing catheter ablation of atrial fibrillation (AF) were selected.The patients were divided into 3 age groups:30 59 yr group (n=279),60-74 yr group (n=100),and 75-87 yr group (n =41).The effect of operation and complications during operative and postoperative periods were evaluated.Patients were followed up for at least 6 months,and the rate of atrial fibrillation reocurrence and life quality were recorded.Results Among 480 catheter ablation procedures,in 7 (1.5％) patients occurred main complications,while in 5 (1.0％) patients appeared other complications.The incidence of main complications in 3 groups were 1.1％ (3 patients),2.0％ (2 patients) and 4.9％ (2 patients) respectively,other complication rates in 3 groups were 0.7％ (2 patients),1.0％ (1 patient) and 4.9％ (2 patients) respectively and there were no differences between groups (all P＞0.05).During follow-up,the cases without AF relapse were 68.5％ (191 patients),66.0％ (66 patients) and 57.1％ (23 patients) respectively,and the patients with AF paroxysm were 21.1％ (59 patients),21.0％ (21 patients),29.3％ (12 patients) respectively,and there was no significant difference between groups (all P＞0.05).And no difference was found in improvement degree of life quality among three groups (P＞0.05).Conclusions Catheter ablation is safe and effective in elderly patients.For patients over 75 years with many types of cardiovascular diseases,catheter ablation is effective to control the relapse of AF,can significantly improve the quality of life,and has no increased risk of complications.