Study On Paclitaxel Inhibiting Haze After LASEK In Rabbits

Objective:To investigate the inhibiting effects of paclitaxel(taxol) on haze after subepithelial keratomileusis(LASEK) in rabbits.Methods:1 To establish rabbit LASEK model,thirty-six healthy New Zealand white rabbits,after exclusion of eye diseases,were undergone-10.0 diopter LASEK operation. 2. All rabbits were equally divided into three groups in randomized method.by self-control mode.Group 0.3mg/m L paclitaxel treating group during operation;Group 2:0.02% MMC treating group during operation;Group 3:Balance saline solution(BSS) treating group during operation,as control group 12 rabbits in each group.Part 1:To randomly select 4 rabbits(8 eyes) in each group,regularly observe corneal epithelium healing process and ocular signs.assess the extent of haze by slit lamp microscope,when 1 week,1month and 3 months after operation.Part 2:Corneal epithelium histopathologic examination,transmission electron microscope observation and immunohistochemistry examination testing TGF-β1 were applied when 1 week,1month and 3 months after operation.Results:1 Evaluation by slit lamp microscope after LASEK:corneal epithelial tissue of all three groups were recovered in one week after LASEK,and there was no significant difference among the three groups.After 1 week,1 month,3 months,the differences were statistically significant(P <0.01) among the three groups on Haze degree,and the paclitaxel and mitomycin group were lower than BSS group(P <0.01),but the comparison between paclitaxel and mitomycin group,difference of Haze degree was not statistically significant(P > 0.05);no significant difference(P > 0.05) among the three groups after three months.2 Corneal epithelium histopathologic observation:Thickness of corneal epithelia and epithelial layers obviously increased after surgery.Corneal stromal cells slight concentration appeared in paclitaxel group and mitomycin group,but not in BSS group.1 week after surgery,inflammatory cells appeared in corneal stroma.TGF-β1 of the stroma in BSS group increased more than that in paclitaxel group and mitomycin group(P<0.01);TGF-β1 in mitomycin group increased more than that in paclitaxel group(P<0.01).Corneal structure appeared regularly in paclitaxel group and mitomycin group,but not in BSS group 1 month after surgery,and the level of TGF-β1 in the stroma decreased.3 Corneal ultrastructure observation:by light microscope we found that each group has a significant degree of corneal epithelium thickening,increased epithelial cell layers.In paclitaxel group and mitomycin group,only a small number of fibroblast cells aggregation phenomena in corneal stroma,but BSS group more.Conclusion:Paclitaxel may obviously inhibit corneal haze after LASEK,and the mechanism may be paclitaxel decreasing TGF-β1 level in corneal stroma layer in early stage after operation,inhibiting fibroblast proliferation and transformation,which was similar to mitomycin.Paclitaxel is a promising medicine to inhibit corneal haze after LASEK,and the results of the study suggest the feasibility and clinical basis that paclitaxel may be used to control corneal haze after LASEK.