兔角膜后弹力层剥除联合深板层内皮移植术后植片与植床愈合的观察

The study of corneal wound healing in rabbits after descemet's stripping endothelial keratoplasty

目的探讨小切口下兔角膜后弹力层剥除联合深板层内皮移植(DSEK)术后不同时间植片与植床的愈合情况。方法30只新西兰大白兔,供体组10只(20只眼),受体组20只(20只眼),右眼为实验组,行同种异体DSEK手术,左眼为正常对照组。术后裂隙灯定期观察角膜透明度;应用SL-OCT观察植片与植床的贴附情况及角膜厚度;分别于术后1、2、3、4、8周各取兔4只,制作角膜组织病理学切片,光镜下观察植片与植床的愈合情况。结果实验组中1只眼由于植片严重卷曲未与植床贴附导致角膜持续混浊水肿,其余19只眼全部恢复透明。裂隙灯下见术后第1d角膜水肿严重,以后逐渐减轻,术后4周角膜完全透明。SL-OCT见各个时间点植片与植床均紧密贴附,术后第1d角膜明显增厚,以后逐渐变薄,至第4周角膜恢复到正常的厚度和形态。光镜下组织学观察,术后早期植片与植床界面清晰易辨,胶原纤维间缝隙增宽,排列紊乱。术后4周植片与植床的界面辨认不清,胶原纤维结构和排列基本恢复正常,角膜中央光学区无瘢痕形成。结论DSEK术后,植片与植床能迅速达到无瘢痕的组织学愈合,该愈合对角膜透明度的恢复起重要作用。

Objective Descemet＇ s stripping endothelial keratoplasty （DSEK） is a new procedure and is currently in evolution. There have been no published reports about the wound healing up to now. This paper aimed to observe the process of corneal wound healing in rabbits after DSEK with small incision. Methods Thirty rabbits were divided into the donor and recipient groups including 10 and 20 rabbits respectively. DSEK was performed in the right eye, and the left eye was used as normal control. Corneal transparency was clinically observed under the slit lamp, and the attachment between the donor disc and recipient＇ s bed and the change of corneal thickness were evaluated using SL-OCT. Four rabbits were killed at 1 week,2,3,4 and 8 weeks postoperatively,and bilateral corneal buttons were harvested for histological examination（ HE staining）. Results Clear cornea could be obtained in 19 recipient eyes postoperatively. The cornea of 1 recipient eye was opacity because of the dislocation of the donor disc. Slit-lamp examination showed serious corneal edema at 1 day postoperatively and the cornea was completely clear at 4 weeks posloperatively. The donor disc and recipient＇ s bed were adhered well under the SL-OCT,and the cornea was obviously thicker than normal rabbit eve at 1 day postoperatively, and then gradually became thinner, and 4 weeks later, corneal thickness restored to normal. Under the light microscope,the interface of the donor disc and recipient＇ s bed was apparent in the early period of postoperatiou. The slots between the collagen fibrils were wider than normal rabbit eve and the arrangement of collagen fibrils was disorder. In 4 weeks postoperatively,the interface of the donor disc and recipient＇ s bed was invisible and the collagen fibrils arranged in good order without scarring. Conclusion The corneal wound healing is rapid after DSEK without scarring in the central optical zone, which plays an important part in the recovery of corneal transparency.