| BackgroundHaze is the major complication after PRK,it is seriously influences the visual quality of patients,excessive corneal healing and fibroplasia are the main reasons of the formation.Anti-angiogenic drugs are currently widely used in the treatment of fundus diseases.Previous studies have found vascular endothelial growth factor inhibitor cam prevent fibrosis process.However,the impact of Conbercept on postoperative haze of photorefractive keratectomy(PRK)is unclear.ObjectiveTo investigate the effect of Conbercept on rabbit’s haze after PRK and detect the expressions of TGF-β1,MMP-2 and a-SMA by immunochemistry,then provide a new idea for the prevention of haze.Methods64 pedigree New Zealand white rabbits were randomly divided into four groups,16 rabbits in each group,PRK was performed on their right eyes,and one surgery group didn’t do any treatment(PRK group),the other three surgery groups were respectively given postoperative subconjunctival injection of 0.05ml normal saline solution,0.5mg(0.05ml)Conbercept,1mg(0.1ml)Conbercept.In addition,another 8 rabbits were randomly chosen as control group.The healing of postoperative corneal epithelial was observed by slit lamp biomicroscope,and the degree of haze was made based on Fantes.8 rabbits in the surgery groups and 4 rabbits in the control group were killed in the first week and the fourth week.The corneal tissue was stained by hematoxylin-eosin,and the expressions of TGF-β1,α-SMA and MMP-2 were detected by immunochemistry.ResultsCorneal epithelium of all operative rabbits healed completely at 3-5 days(F=0.37,P=0.77).During the observation,haze in each surgery group reached the highest value in about one month,and haze in the Conbercept lmg group was most serious,followed by PRK group and normal saline solution 0.05ml group,haze in Conbercept 0.5mg group was significantly reduced(first week,F=7.838,P=0.001;forth week,F =11.804,P=0.000),but no significant difference between PRK group and normal saline solution 0.05ml group(first week,P=0.451;forth week,P=0.632).Hematoxylin-eosin staining showed that corneal epithelial cells and fibroblasts in superficial stroma proliferated in one week after PRK,which lead to the disorder of cells and collagen fibers,and the extent of hyperplasia was the same as that of haze.At one week after operation,the expressions of TGF-β1,α-SMA and MMP-2 were significantly different between groups(positive cells:F=61.960,P=0.000;F=89.622,P=0.000;F=1368.0255 P=0.000;mean optical density:F=1183.5625,P=0.000;F=1418.653,P=0.000;F=1496.525,P=0.000),at four weeks after operation,the expression of the three factors were increased significantly(positive cells:F=501.713,P=0.000;F=442.884,P=0.000;F=1700.421,P=0.000;mean optical density:F=1667.455,P=0.000;F=1788.943,P=0.000;F=1513.968,P=0.000).At each time point,compared with Conbercept lmg group,the expressions of factors in PRK group and normal saline solution 0.05ml group were apparently lower,but it was apparently higher than Conbercept 0.5mg group,and the factors were weakest in control group.Besides,no significant difference was seen between PRK group and normal saline solution 0.05ml group(positive cells:P=0.624;P=0.499;P=0.774;mean optical density:P=0.565;P=0.595;P=0.908).ConclusionSubconjunctival injection of appropriate Conbercept can inhibit the formation of haze after PRK,but overdose of Conbercept leads to opposite effects. |
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