Establishment and evaluation of the mice model of oxygen induced retinopathy

Aim:To establish the mice model of oxygen induced retinopathy(OIR),and evaluate the model overall.Methods: Seven-day-old C57BL/6J mice of clean grade were randomly random divided ized into oxygen-induced retinopathy group and control group.In oxygen-induced retinopathy group,mice were exposed to 75% oxygen for 5 days and then to room air;in control group,mice were raised in room air.Eye samples of mice from each group were excised at postnatal 7 days(Postnatal days 7,to express P3,the same below),P12,P14,P17,P22,P25,and P30 respectively.The morphologic changes of retinal vessels were estimated by observing the vascular pattern with ADPase staining retina flatmounts,and quantitated by counting the number of new vascular cell nuclei extending into the internal limiting membrane by HE stain,using VG stain and immunohistochemical stain to assess the interstitial fibrosis of the retina.Results: ①An oxygen induced retinopathy(OIR) in mice was successfully induced following 5-day exposure to 75% oxygen,and the quantitative results of the retinal neovascularization showed: there was a mean of 33 neovascular nuclei per cross-section extending into the vitreous in hyperoxia compared to less than 1 nuclei in the normoxia control(P0.000 1).②Exploring the situation of the retina fibrosis: The retinal neovascularization began to fade after P17;the results of VG stain and immunohistochemistry stain were all negative.Conclusion:The mice model of OIR duplicated preferably the acute pathological changes of retinopathy of prematurity(ROP) such as angiemphraxis and retinal neovasculatization,but it not present the serious pathological changes such as retinal fibrosis and retinal detachment of ROP.