丝裂霉素C治疗准分子激光屈光性角膜切削术后角膜上皮下雾状混浊的实验研究

目的：探讨丝裂霉素C治疗准分子激光屈光性角膜切削术治疗（PRK）后膜上皮下雾状混浊（haze)的作用。方法：对54只新西兰白兔双眼行PRK，随机分为4组，术中一次性应用0．008％丝裂霉素C（I组），术后给予0．02％丝裂霉素C点眼（Ⅱ组）及0．1％塞地米松点眼（Ⅲ组），术后平衡盐液点眼作为对照（Ⅳ组），并行裂隙灯，角膜内皮镜，光镜，电镜检查，结果：术后4周，8周，Ⅰ组haze最轻（与对照组比较P＜0．01）；Ⅱ组与Ⅲ组角膜haze程度相同（P＞0．05），均较Ⅳ组为轻（P＜0．05），但较Ⅰ组为重（P＜0．05）。光镜及电镜检查表明：Ⅳ组术区角膜上皮细胞过度增生，前基质成纤维细胞增生活跃，纤维排列明显紊乱；Ⅰ、Ⅱ组及Ⅲ组上皮细胞和前基质成纤维细胞的增生以及胶原纤维合成均受抑制，纤维排列较整齐，其中以Ⅰ组最为明显，纤维排列整齐。结论：丝裂霉素C减轻PRK术后角膜haze，且无明显副作用，可望成为防治角膜haze的一种新药。

Experimental study on topical mitomycin C to treat hazeafter photorefractive keratectomy in rabbits

Objective To evaluate the efficacy of topical mitomycin C in preventing haze after excimer laser photorefractive keratectomy (PRK). Methods Fifty-four New Zealand rabbits were divided into 4 groups to receive bilateral 193 nm excimer laser myopic photorefractive keratectomy. In group I, the eyes were treated with 0.008% mitomycin C drops during operation, group II with 0.02% mitomyin C after operation, group III with 0.1% dexamethasone after operation, and group IV with a balanced salt solution after operation as control. Slit-lamp, specular microscopic, light microscopic and transmission electron microscopic examinations were made. Results The haze formed 4 and 8 weeks after the operation was the least in group I, less in groups II and III, as compared with that in the control group IV. Light microscopy and transmission electron microscopy revealed that the excessive epithelial hyperplasia and subepithelial collagen proliferation found in group IV, were inhibited in all of the other 3 groups, especially in group I. The rrangement of collagen fibers was normal in group I and about normal in groups II and III. Conclusion Mitomycin C can reduce the formation of corneal haze after PRK and has no apparent side effects.