Effects of Avastin on Experimental Corneal Neovascularization in Rat
|School||Guangzhou Medical College|
|Keywords||Avastin corneal epithelial defect healing rate dexamethasone corneal neovascularization|
ObjectiveThis study attempted to evaluate Avastin on the healing rate of rat corneal epithelial defect model.And we investigate the effect of topically administered agents Avastin,dexamethasone and drug combination on experimental corneal neovascularization (NV) and its mechanism in rats.Materials and methods1. SD rats were randomly divided into two groups:the defect group and normal group.The corneal epithelial defect model were made in experimental group A and control group A,four rats(8 eyes) were divided into each group in the normal group.Two rats(4 eyes) were randomly divided into experimental group B and control group B without untreated.The 5g?L-1Avastin eye drop was given to experimental group,and topical instillation of 0.9%NaCl solution was given to control group.Photographs of group A were taken until corneal epithelial healed every 12,18,24,36 hours respectively;Morphology and ultrastructure of rat cornea were evaluated by light and electron microsope in group B.2. SD rats were randomly divided into four groups after alkaline cauterization of cornea,12 ones in each group.Then topical instillation of 0.9% NaCl solution(group A),dexamethasone(group B),Avastin(group C)and dexamethasone+Avastin (group D) was continued for 12 days.The growth of corneal NV was observed under the slit lamp, and the corneal NV area was calculated.Hematoxylin-eosin staining of each cornea sample was performed for the pathological examination on the seventh day.Expressions of VEGF in cornea of each group were detected by immunohistochemistry. Results1. The ratio of corneal epithelial defect area showed no significant difference (P>0.05) between experimental group A and control group A at 12h,18h and 24h.2. Corneal clouding,edema,epithelial defect were not found after dropped with 5g·L-1Avastin eye drop on normal rat,s cornea.The corneal histological structure and ultramicrostructure were normal without the inflammatory cell infiltration in all corneas compared with control group B.3. The area of corneal NV was smaller in Avastin group,Avastin+dexamethasone group and 0.1% dexamethasone group in 3,6 and 12 days than 0.9% NaCl solution group(all P<0.01).Infiltration of inflammatory cells and neovascular were detected in 0.9% NaCl solution group,but little of inflammatory cells and neovascular were found in Avastin group,dexamethasone group and Avastin+dexamethasone group.Expression of VEGF was much high in 0.9% NaCl group compared with dexamethasone group and Avastin group,and that in Avastin+dexamethasone group was weaker.4. No significant difference in corneal NV area was found between 0.1% dexamethasone group and Avastin group (P>0.05).Conclusions1. There was no effect on the healing rate of rat corneal epithelial after short-term ocular application of 5g·L-1Avastin.2. The rat cornea structure didn,t change after short-term ocular application of 5g·L-1Avastin.3. Topical application of Avastin,dexamethasone had inhibit corneal NV significantly.Avastin and dexamethasone show a synergistic effect in suppressing the expression of VEGF and inflammation cells.4. Avastin had the effect of anti-inflammatory.