超薄角膜瓣准分子激光原位角膜磨镶术和准分子激光上皮瓣下角膜磨镶术对兔角膜组织愈合影响的对比研究

目的 探讨超薄角膜瓣准分子激光原位角膜磨镶术(LASIK)和准分子激光上皮瓣下角膜磨镶术(LASEK)对兔角膜组织愈合的影响.方法 实验研究.32只新西兰白兔随机分为两组各16只,一组右眼行超薄角膜瓣LASIK,另一组右眼行LASEK,左眼对照.两组兔眼均行-10.00 D准分子激光切削.术后裂隙灯显微镜观察角膜情况,术后1、3个月取两组兔激光切削区角膜分别进行光镜、透射电镜检查,并采用免疫组化和RT-PCR法检测Ⅰ型胶原、Ⅲ型胶原、纤维连接蛋白及转化生长因子β1(TGF-β1)在其中表达水平.RT-PCR结果采用灰度扫描,结果采用t检验进行组间比较.结果 超薄角膜瓣LASIK组术后角膜愈合反应轻、恢复快,角膜保持透明,无角膜上皮下雾状混浊(haze)发生.LASEK组术后角膜愈合反应重,恢复慢,1个月时角膜发生1级haze(62.5%)和2级haze(37.5%),3个月时发生0.5级haze(43.75%)和1级haze(56.25%).术后1、3个月超薄角膜瓣LASIK组和LASEK组角膜前基质内均有Ⅲ型胶原、FN和TGF-β1蛋白及其mRNA的表达,但LASEK组的表达明显增强(t=18.47,11.98;P<0.01);两组间Ⅰ型胶原蛋白及其mRNA的表达无统计学意义(t=0.72,0.36,0.47,2.38;P>0.05).超薄角膜瓣LASIK组术后3个月Ⅰ型胶原、Ⅲ型胶原、FN、TGF-β1 mRNA的表达与正常对照组差异无统计学意义(t=2.42,1.54,-0.83;P>0.05).结论 动物实验提示,模拟高度近视治疗的超薄角膜瓣LASIK术后角膜组织愈合反应明显优于LAsEK术后.(中华眼科杂志,2009,45:594-600)

The effects on corneal wound healing of LASIK with ultra-thin corneal flaps and LASEK in rabbits

Objective To evaluate the corneal wound-healing response of LASIK with ultra-thin corneal flaps and LASEK in rabbits. Methods It was an experimental study. Thirty-two adult New Zealand rabbits were divided into 2 groups with 16 each. Two surgical procedures, LASIK with ultra-thin corneal flaps and LASEK were performed on the right eye of each group, with the left eye as control. A myopic ablation of 10 diopters was performed in each group. Corneal wound-healing and histopathological changes of the ablation zone were studied through slit lamp, hght microscope and transmission electronic microscope. The expression levels of collagen Ⅰ , collagen Ⅲ, fibronectin (FN) and transforming growth factor beta-1 (TGF-β1) were investigated by immunohistochemistry and RT-PCR assays. Results In the group of LASIK with ultra-thin corneal flaps, the corneas were clear without haze followed by slight wound healing and fast recovery. While in the group of LASEK, corneal wound healing was obviously delayed. There was haze in grade 1 (62. 5%) and grade 2 (37.5%) in 1 month, with grade 0. 5 (43. 75%) and grade 1 (56. 25%) in 3 months. 1 month and 3 months after surgery, proteins and mRNA of collagen Ⅲ, FN and TGF-β1 were expressed in the anterior corneal stromal layer in each group. But the expression was much higher in the group of LASEK (t=18.47, 11.98, P<0.05). The protein and mRNA expression of coflagen Ⅰ had no difference between the two groups (t = 0. 72,0. 36,0. 47,2. 38, P > 0. 05). The mRNA expression of collagen Ⅰ, collagen Ⅲ, FN and TGF-β1 had no statistical difference between the groups of control and LASIK with ultra-thin flap in 3 months (t = 2. 42,1.54, - 0. 83, P > 0. 05). Conclusion According to the animal experiments, it was suggested that the corneal wound-healing response of LASIK with ultra-thin corneal flaps was much better than that of LASEK. (Chin J Opbthalmol, 2009,45:594-600)