AIM: To establish the murine model of oxygen induced retinopathy(OIR)and to evaluate the inhibition of retinal neovascularization by erythropoietin(EPO)blockade.

METHODS: Neonates of C57BL/6 mouse(P7)were exposed to 75%±2% oxygen for 5d and return to normal air environment when 12d(P12)to establish oxygen-induced retinal neovascularization model. The neonates were divided into groups, injected with 0.5μL solution containing 25ng(group A), 50ng(group B), 250ng(group C)of soluble erythropoietin receptor(EPO-R)or PBS(group D)at P12, P14 and P16 in the right eye. On P17, the litters were sacrificed and their right eyes were enucleated and fixed with 4% paraformaldehyde, made pathological section. The number of breakthrough internal limiting membrane neovascular nuclei was counted with pathological retinal morphology, understanding theproliferative degree of retinal neovascularization.

RESULTS: The pathological sections showed the neovascular cell nuclei which penetrating the inner limiting membrane in intravitreal EPO receptor injection group was reduced statistically than that in PBS injection group, the difference was statistically significant(P<0.01). And, neovascular nuclei count differences in the various concentrations of EPO receptor group was statistically significant(P<0.01). With the EPO receptor concentration increase, neovascular endothelial cells broken through the internal limiting membrane was reduced.

CONCLUSION: Intravitreal injection of soluble EPO receptor can block EPO and improve neovascularization. The new method is expected to become new treatment of ocular neovascular diseases.