Study On Corneal Neovascularization After Intervention With Bevacizumab In The Early Period Of Alkali-burned Rat Corneal

Objective:To evaluate the inhibition effect of bevacizumab on rat cor-neal Neovascularization model.Methods:Twenty-eight wistar female rat, were randomly divided into two grous:Control group and Treatment group, each include 14 rats. Twenty-eight rats were used to make corneal alkali-burned model by 1 mol/L NaOH. Control group was given 0.25% of Chloramphenicol eye drops, Experimental group was given 0.25% of Chloramphenicol eye drops and 25mg/ml bevacizumab. Different eye drops were applied 2 times/day for 14days. We observed corneal neovascularization on the 3d,5d,7d,14d after injury under slitlamp microscopy, taking count of the microvessl under optical microscopy, HE observation and examined the expression of VEGF.Results:1. To observe the rat's cornea by slitlamp microscope:We found brush angiogenesis at corneascleral margin on the 3th day, new blood vessels invaded corneal on the 5th day, corneal neovascularization interlaced into mesh, some vessels penetrated alkali burn spot on the 7th day, corneal neovascularization almost occupied the entire corneal on the 14th day in control group. And brush-angiogenesis appeared some quadrant on 5th, corneal neovascularization invaded shallow layer of corneal stroma, however raritas and small on 7th day, corneal neovascularization distributed in the lateral of alkali bum spot on 14th in experimental group.2. Neovascularization count under the microscope:the control group neovascularization was (137.74±21.53),experimental group (42.70±8.62). P <0.05, differences were statistically significant.3. HE observation:We found corneal epithelial loss or some bubble-like necrosis on the 3th day. Limbal and serious peripheral inflammatory cells, showing single layer made of capillary endothelial cells around the cavity on the 7th day. epithelial cell layers when increasing fiber matrix layer edema disordered, showing a large number of lymphocytes and new blood vessels disordered. Descemet rupture wavy folds endothelial cells completely destroyed on the 14th day. However corneal epithelial superfi-cial necrosis, collagen fiber swelling, We can see a small bubble but arranged regular, corneal neovascularization relatively smaller on the 7th day. The corneal epithelial integrity has become more orderly, neo-vascularization and inflammatory cell has become sparse on the 14th day in experimental group.4. Detected the immunohistochemical staining of VEGF, the expression of VEGF markedly increased in control group(862.00±118.67)compared with the experimental groups(P<0.05).Conclusion:Bevacizumab can inhibit early period corneal neovasculari-zation of corneal alkali-burned rats. Bevacizumab eyedrops is expected to be a specific safe and effective clinical treatment for CNV formation, and has the potential to inhibit CNV.