中文摘要：

目的观察准分子激光原位角膜磨镶术（LASIK）手术前后角膜上皮超做结构的变化和角膜神经再生情况。方法新西兰白兔48只，分为2组进行实验，每只兔1只眼行常规LASIK，分别在术后即刻、1d、1周，1、3、6个月，每组各取4只角膜，进行透射电镜、扫描电镜分析和角膜神经染色观察。结果透射电镜观察显示：术后兔眼角膜表面的微绒毛不规则，微绒毛密度明显减少；扫描电镜可见细胞间连接异常，微绒毛有水肿和断裂的迹象。在术后1周左右基本恢复正常。角膜上皮微绒毛数量在术前和术后即刻相比差异有统计学意义（P〈0．05），与术后1d和7d相比差异无统计学意义（P〉0．05）。角膜神经染色显示术后1d，神经损伤边界清楚，神经纤维被截断，至术后1个月即可见再生神经长人切断的角膜瓣内；术后6个月，再生神经长人角膜瓣内近中心区。结论LASIK术后早期角膜上皮超微结构的改变，可能是造成术后干眼症的原因之一。LASIK术后被切断的角膜神经修复是从断端逐渐向角膜瓣内长人。

英文摘要：

Background The ultrastructure change and growth of corneal nerve after laser in situ keratomileusis （LASIK） are some influent factors to the stability of tear film and the sensibility of cornea. Some relevant studies are lack up to now. Objective This study is to observe the changes of ultrastrueture of corneal epithelium and regeneration of corneal nerve fiber. Methods LASIK was performed on the lateral eyes of 48 New Zealand white rabbits. Rabbit eyes were excavated at instant in postoperation,one day, seven days, one, three and six months after LASIK. Change of corneal ultrastructure and corneal nerve staining were examined under the scanning electron microscope （SEM） and transmmision electron microscope （TEM） at the time points mentioned above. The numbers of microvilli of corneal epithelial ceils in different postoperative time were analyzed. 10% AuCl was used to evaluate the growth status of corneal nerve in different time after LASIK. Results Irregularity of microvillus of corneal epithelial cells, degrease of cell density were seen under the TEM and some cavities could been observed in the instant of postoperation. The connection abnormality of intereells, dropsy and rupture of microvillus were presented under the SEM, However,the ultrastrueture of corneal epithelial cells was almost normal in 7 days after LASIK. The numbers of microvillus in corneal epithelial cells were significantly declined in the postoperative instant group compared with preoperative group （P 〈 0. 05） ,but no evidently difference was found in postoperative 1 day and 7 days groups compared with preoperative group （ P 〉 0.05）. Corneal nerve staining showed that in 1 day after surgery,nerve plexus was deprivation and boundary of nerve injury was clear and nerve fibers were cut off. After one month some reborn nerve fiber grew into the cornea flap. Reborn corneal nerve fiber can be seen at center laser ablation area after six months of LASIK. Conclusion The ultrastructure change of corneal epithelial cells in the