Abstract: Objective To identify the utility of eicosapentaenoic acid (EPA)on diabetic retinopathy (DR)in vivo.Methods Proliferative diabetic retinopathy (PDR)Sprague-Dawley rat (n=24)was induced by application of streptozotocin associated with vascular endothelial growth factor (VEGF).Sprague-Dawley rats were randomly divided into D group (n=1 2 )representing medication administration group at background DR stage,E group (n = 8 ) representing medication administration group at pre-proliferation DR stage,F group (n=4 ) representing medication administration group at proliferation DR stage,then EPA was inj ected intravitreously. Fundus pathological changes were observed by fluorescence fundus angiography(FFA),CD105 positive retinal vascular endothelial cells were observed by microscope with immunohistochemistry technique.The results were compared with diabetic rat models established in our prior study.Results FFA demonstrated the best effect in E group in two weeks after EPA inj ection,whereas effective and augmented time-dependently in D group during eight weeks after EPA inj ection.In six weeks after EPA inj ection in E group,the effect decreased obviously as compared with that 2,4,8 weeks after EPA injection in D group.As compared with non-medication group,retinal neovascularization was not detected at the same course of this disease. Retinal neovascularization was also detected and diabetic retinopathy was not relieved in EPA injected eyes in F group.CD105 immunohistochemistry described there were no CD105 positive vascular endothelial cells at the same course of disease in D and E group.But CD105 positive cells were still observed in F group.Conclusion EPA can suppress DR development by blocking VEGF receptor flk-1 .

Key words: retinal diseases, vascular endothelial growth factors, fluorescein angiography