LASIK角膜瓣蒂不同位置的神经损伤及再生的形态学研究

目的 在形态学上比较兔眼角膜瓣上方蒂和鼻侧蒂之间角膜神经损伤及再生过程的差异.方法 选用健康、纯种新西兰白兔35只,随机分为7组,每组5只,制作角膜瓣蒂位置随机一眼留在鼻侧,另一眼留在上方,分别于术后1、3 d,1、4、6、10、20周处死,每组5只兔（10只眼）.取下的角膜做组织化学染色,用氯化金染色法在光镜下观察角膜末梢神经的形态学改变.计算角膜新生神经纤维的数目,行统计学t检验分析.结果 兔角膜瓣上方蒂和鼻侧蒂在角膜神经恢复和再生过程的比较无显著性差异.均表现为术后1 d角膜瓣边缘部位的神经受到不同程度的损害;术后3 d开始修复;术后10周被切断的基质内神经发出更多新生的神经索,与相邻基质神经相互吻合,角膜瓣内神经的形态和密度基本恢复到术前水平.结论 兔角膜瓣两种位置蒂的角膜神经损伤及再生修复过程无明显差异.

Morphology of corneal nerve damage and repair after LASIK with upper and nasal hinge corneal flap

ObjectiveMaking a perfect corneal flap is critical for the excimer laser in situ keratomileusis (Lasik),but damage of corneal nerve during the surgical procedure affects the nutrition of cornea tissue.This study aimed to compare the morphologic differences of the rabbits cornea nerves in the process of damage and repairing after Lasik with nasal hinge and upper hinge corneal flaps.MethodsThirty-five adult New Zealand white rabbits were divided into 7 groups.The Lasik with upper hinge corneal flaps was performed on lateral eyes of rabbits and the nasal hinge flaps on the opposite eyes.Five rabbits were sacrificed and 10 cornea tissues were collected at 1 day,3 days,1 week,4,6,10 and 20 weeks in post-operation.The morphology of corneal nerve damage and regeneration was observed under the light microscope using photochemical gold chloride impregnation.The numbers of regeneration of neuron fibers in the two kinds of corneal flaps at different times were analyzed.ResultsCorneal nerve damage and regeneration in upper hinge corneal flaps were similar to those of nasal hinge flaps.One day after the surgery,the stroma nerves at wound edge were cut in the superficial stoma.At the 3rd day,the new thin fibers began to grow via the wound margin into the flap area beneath the epithelium.At the 10th week,the numbers of regenerating nerve leashes were increased.The regenerating nerve leashes sent the anastomosing fibers to neighboring stroma nerves.At the 20th week,the epithelia,subepithelia and anterior stroma innervation reached normal nerve density and structure.ConclusionThere is no significant difference in morphology of corneal nerve damage and regeneration between upper and nasal hinge of corneal flaps.