丝裂霉素C诱导PRK后角膜基质细胞凋亡的实验研究

Mitomycin C-induced apoptosis of stromal cells after photorefractive keratectomy

目的探讨丝裂霉素C(MMC)对准分子激光角膜切削术(PRK)后角膜基质细胞凋亡的影响。方法30只兔随机取1只眼行PRK并术中使用0.02%MMC为PRK+MMC组,另1只眼仅行PRK设为PRK组,2只兔设为正常对照组。观察角膜上皮下混浊(haze)程度;采用苏木精-伊红染色法、TUNEL法和免疫组织化学法观察角膜细胞。结果术后1周,1、2、3个月角膜haze差异均有统计学意义(P<0.05)。术后1周,1、2、3个月PRK+MMC组与PRK组TUNEL染色、α-SMA阳性细胞数相比,差异均有统计学意义(P<0.05)。结论术中眼局部应用0.02%MMC溶液可促进活化的角膜基质细胞凋亡,减轻PRK术后haze。

Objective Recently excimer laser surface ablation is more corcerned,but the serious haze after operation will impact on the vision.This study was to investigate the effects of mitomycin C（MMC）on the apoptosis of corneal stromal cells after photorefractive keratectomy（PRK）and evaluate the effects of MMC on corneal haze histopathologically.Methods Thirty-two Japanese rabbits（64 eyes）were randomly treated with PRK＋MMC in one eyes and PRK in the fellow eyes,and 2 rabbits（4 eyes）without any treatment were used as control.Corneal haze and corneal histopathologic response after surgery were investigated under the slit lamp and light microscope respectively.Cornea stromal cell apoptosis and expression of α-SMA was evaluated by terminal deoxyribonucle-otidyl transferase-mediated deoxynuridine triphosphate nick end labeling（TUNEL）assay and immunocyto-chemical analysis respectively.Both number of TUNEL and α-SAM-positive cells were analyzed to explore their effects on corneal haze.Results In 1 week,1 month,2 and 3 months after the operation,corneal haze was significantly less in PRK＋MMC group than that in the PRK group（P〈0.05）,and the TUNEL positive cells were significantly more in mitomycin C group than that in the PRK group（P〈0.01）.α-SMA-positive cells started to appear apparently at 1 week in both two groups and were significantly less in mitomycin C group than that in PRK group（P〈0.01）.Conclusion Mitomycin C may reduce corneal haze after PRK by inducing apoptosis of activated keratocytes and inhibiting the myofibroblast generation.Therefore,it is an effective medicine for preventing the haze after PRK.