兔机械性角膜上皮损伤后伤口愈合的形态学动态变化

Dynamic Morphological Changes of the Rabbit Cornea Wound Healing after Mechanical Epithelial Injury

目的观察兔机械性角膜上皮损伤后伤口愈合的形态学动态变化。方法选取新西兰大白兔12只,随机分为A、B两组,均建立机械性角膜上皮损伤模型(刮除直径为8mm的角膜中央上皮),术后给予盐酸林可霉素滴眼液滴眼,3次/日,1滴/次。A组在建模后第0、1、4、7天共4个时间点采用前节裂隙灯照相系统进行眼表照相,并计算损伤面积。B组在建模后第1、4、7天,按随机数字表法取2只兔的实验眼角膜,行透射电镜及病理检查。结果前节裂隙灯照相系统记录了不同观察时间点损伤范围(伤口愈合面积)的动态变化。造模后第1天,角膜上皮全层缺如,损伤边缘处上皮细胞胞膜向损伤区内伸出褶皱的伪足;造模后第4天,上皮自周边向缺损区域爬行生长,覆盖整个角膜,可见2～3层细胞,主要为基底细胞和多角细胞,细胞连接松驰;造模后第7天,再生上皮分化较完全,约5～6层细胞,极向齐,连接较紧密,可见均匀分布的半桥粒结构。结论兔机械性角膜上皮损伤后伤口愈合的动态形态学变化包括上皮细胞向心性移行、增殖,以及随后的分化,连接。

Objective To observe the dynamic morphological changes of the cornea wound healing in rabbits after mechanical epithelial injury.Methods 12 New Zealand albino rabbits were randomly devided into 2 groups（A,B）.The group A was experimental group,including the rabbit model of mechanical cornea epithelial injury by scraping an area of 8 mm in diameter.The group B was control group.Both groups were administered with lincomycin hydrochloride eye drops for 3 times a day and 1 drop each time.The eyes of group A were photographed with an anterior segment slit lamp optical system and their defect areas were measured on days 0,1,4 and 7,respectively,after modeling.The corneas of 2 rabbits from group B were taken by random number table and samples were taken for light and transmission electron microscopic examination on days 1,4 and 7,respectively,after modeling.Results The anterior segment slit lamp optical system revealed the dynamic changes of the defect area（healing area）at different observation time points.At 1 day after modeling,all layers of cornea epithelium were lost and the epithelial cells at the edge of the defect formed folded pseudopodia towards the defect area.At 4 days after modeling,the epithelium grew from the periphery of the defect area and gradually covered the whole cornea.2 to 3 layers of loosely connected cells were seen,most of them were basal cells and polygonal cells.At 7 days after modeling,5 to 6 layers of tightly connected regenerating epithelial cells with apparent polar direction.The epithelial cells were fully differentiated with evenly distributed hemidesmosomes.Conclusion The dynamic morphological changes of the wound healing process of rabbit cornea epithelial defects,formed by mechanical epithelial injury,include epithelial cell proliferation,centripetal migration of these cells towards the center of the wound area,and their subsequent differentiation and cell junction formation.