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Study On The Prevention And Treatment Effect Of Intravitreal Bevacizumab Injection In Diabetic Retinopathy Rats Song Chen Objective: To elevate intravitreal Bevacizumab injection on the prevention diabetic retinopathy and retina neovascularization. Method: Randomized controlled trail was performed. Healthy Sprague Dawley rats were constructed for diabetic retinopathy model by streptozotocin (STZ) which were divided into three groups randomly including control model group (DR group) ,high-dose treatment group(H group) and Low-dose treatment group(L group). Evans blue(EB) angiography was used to assess the capillary vessel pattern to ensure modeling construction succeed after 10 weeks. After that,Bevacizumab were injected into the vitreous in the treatment group ,the dose was 2.5mg/ml¡Á4¦Ìl and 1.25 mg/ml¡Á4¦Ìl ,respectively. Nothing was injected into DR group and normal group.2 weeks¡¢4weeks¡¢6weeks after injection,the rats were executed and eyes were enucleated.The expression of VEGF in retinas was assessed by Immunohistochemistry assay . EB perfusion method were used to assess the function of BRB. EB angiography was used to assess the capillary vessel pattern after Bevacizumab injection. Result: Immunohistochemistry revealed the expression of VEGF protein was weakly positive in normal control group, while the DR group was significantly increased.Compared with DR group , therapy groups were significantly decreased. EB perfusion method: 2weeks¡¢ 4weeks and 8 weeks after the treatment ,the dose of EB leakage were significantly different during N group¡¢DR group¡¢ H group and L group£¨P£¼0.05£©. 4 weeks and 8 weeks after the treatment, there were statistically significant differences between the treatment group£¨P£¼0.05£©. EB angiography: DR group:2 weeks after the treatment,the density of microvascular increase;vessels run tortuous;EB leaked from the branch of retinal vessels but no microaneurysms and neovascularization. 4 and 8 weeks after the treatment, retinal vascular irregularly expanded and run tortuosity;there were microaneurysms but no perfusion zone; there was large-scale EB leakage in the peripheral retina.Treatment group: retinal vascular density was significantly higher than the N group and lower than DR group; retinal vascular tortuosity was not obvious, and no dye leakage, and no microaneurysms and no-perfusion zone; Occasionally , there were retina vascular leakage in L group,but no in H group. Conclusion: Intravitreal injection of Bevacizumab is effective in preventing rats DR and retinal neovascularization,it is possible to delay the occurrence of proliferative DR ,The effet of Intravitreal Bevacizumab injection is dose-related. |
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