16周和26周人胎儿角膜的神经分布

THE INNERVATION OF CORNEA IN 16 WEEK AND 26 WEEK FETUS

①目的了解人胚胎期角膜神经的发育和分布方式，为临床角膜疾病、角膜损伤后的神经再生和感觉恢复的研究提供依据。②方法用氯化金神经染色法和连续冰冻切片技术，在光学显微镜下观察１６周和２６周人胎儿角膜神经的发育和分布。③结果１６周和２６周胎儿角膜中均见有一连续的角膜周缘神经丛。自此神经丛发出的神经纤维分３条途径进入角膜上皮，即经结合膜直接进入角膜上皮周缘区；经巩膜和基质浅层进入角膜上皮并分布至上皮周围的２／３区，经基质分布至角膜上皮的中央区。角膜内皮层未见有神经分布。④结论１６周和２６周胎儿角膜神经首先出现于上皮并形成神经网，然后在基质出现少量神经干，内皮没有神经分布。从上皮层至内皮层神经纤维的数量依次递减。

Objective To understand the normal development and innervation of corneal nerve of fetus and provid embryological and neuroanatomical basis for the clinical research of nerve regeneration and sense recovery of diseased cornea. Methods The fetal corneas were treated using the gold chloride nerve staining method and the frozen section technique. The sections were observed with light microscope. Results A series of pericorneal plexues was found around the cornea both in the 16 week and 26 week fetus. The nerve fibers arising from the pericorneal plexues got into the cornea epithelium along three ways, i.e. the nerves innervated the periepithelium, the two third area of the lateral epithelium and central area of the epithelium along the conjunctiva, sclera and stroma respectively. No nerves were found at the endothelium of cornea. Conclusion The corneal nerves appear early and form network of nerve fibers in the cornea epithelium. A small number of nerve trunks appear later in the stroma.There are no nerves in the endothelium. The neural fibers of cornea decrease in number progeressively from epithelium to endothelium. Our results differ from previous authors.