准分子激光原位角膜磨镶术后角膜神经损伤和再生的实验研究

目的 观察准分子激光原位角膜磨镶术（LASIK）术后角膜神经的损伤及术后不同时期的再生情况。方法 取4只大耳白兔，右眼接受近视性LASIK术，左眼为正常对照，另取14只兔双眼接受LASIK术，术后1、3、7d，1、2、3、6个月行氯化金染色，光镜下观察LASIK术后神经的损伤及再生情况。结果 术后深基质层、角膜瓣连接处的上皮下和浅基质层神经未受损，瓣切削处上皮下和浅基质层神经消失。术后不同部位的角膜神经再生程度不同，术后6个月周边部角膜神经形态已接近正常，角膜中央仍无神经分布。结论 近视性LASIK术对不同部位角膜神经的损伤程度不同，术后6个月周边部神经恢复接近正常，中央部神经修复较慢。

Experimental study on corneal nerve damage and regeneration after laser in situ keratomileusis

ObjectiveMany investigators thought that dry eyes after laser in situ keratomileusis (LASIK) is caused by the injury of corneal nerve during the operation.The purpose of present paper was to investigate corneal nerve damage and regeneration at various times after LASIK.MethodsLASIK for myopia was performed on the right eyes of 4 rabbits and the left eyes was as controls,and both eyes of other 14 rabbits received LASIK.Corneal nerve damage and regeneration statues were observed with golden chloride staining under the electron microscope at 6 and 12 hours,1day,3,7 days and 1month,2,3,6 months after operation.ResultsNerve fiber in deep stroma,subepithelium and shallow stroma in the hinge of corneal flap were not damaged,however,subepithelial nerve plexus and shallow stromal nerve out the hinge of corneal flap were absent after LASIK.Budding nerve fibers grew toward shallow stroma and regenerating nerve trunks in deep stromal could be seen in the 3rd day after LASIK.Some regenerating nerves were visualized in subepithelial nerve plexus and shallow stromal nerve with time lapse within 1 month after LASIK.New nerves from deep stroma entered nets and approached shallow stroma at 2 months.Three months later,regenerated nerves of deep stroma joined into subepithelial nerve plexus.The nerve in peripheral cornea showed completely resumed,but no nerve fiber was seen at the center of cornea at 6 months.ConclusionCorneal nerve in different parts was injured after LASIK for myopia,and some nerves regenerate at early phase postoperatively.Six months after LASIK,peripheral corneal nerve fibers show much rapid regeneration in comparison with center ones.