角膜深板层内皮移植术伤口愈合机制的研究

The healing mechanism of lamella interface microkeratome-assisted deep lamellar endothelial keratoplasty

目的 探讨用微型角膜刀行角膜深板层内皮移植术 (DLEK)与穿透角膜移植术 (PK)术后排斥反应的差异及机制 ;研究DLEK术后创面的愈合过程、特点和机制。方法 对两组新西兰白兔分别行DLEK和PK ,对比术后的排斥反应指数 ;术后不同时间取角膜标本进行光镜、电镜和免疫组化检查。结果 实验组排斥反应指数较对照组降低 ;术后 2周角膜基质细胞开始增殖 ,分泌胶原 ;术后植片中央区瘢痕极少 ;Ⅰ、Ⅴ型胶原持续表达 ,Ⅲ型胶原术后 1周于伤口附近表达 ,1～ 2个月时最强。结论 DLEK术后排斥反应少 ,植片中央界面瘢痕轻微 ,优于手剖界面。

Objective To find out the difference of graft rejection reaction between microkeratome-assisted deep lamellar endothelial keratoplasty (DLEK) and penetrating keratoplasty (PKP),and understand the healing course of the lamella interface. Methods Twenty-four New Zealand white rabbits were involved in this study.Twelve Chinese domestic rabbits served as donors.Twelve New Zealand white rabbits received PKP,and other 12 New Zealand white rabbits received DLEK.The difference of rejection index (RI) between the two groups was evaluated.The cornea specimens were prepared and studied by light microscope,electron microscope and immunohistochemical staining. Results The RI of DLEK was obviously lower than that of PKP.The edge cutting by MLK was very smooth.With time gone by,keratocytes enlarged with the proliferation of cell organs.Immunohistochemical staining showed continuous strong expression of collagen Ⅰ,while collagen type Ⅲ only appeared in stroma in the proximity of the wound in the 1 st post-operation week and reached the strongest expression at one postoperative month.Collagen type Ⅴ was weakly expressed over observation-period. Conclusion Graft rejection is less severe in DLEK than in PKP because less foreign tissue is transplanted in DLEK.