兔不同切削量的LASIK术后角膜细胞明胶酶的表达

Expression of gelatinase in cornea cell after the laser in situ keratomileusis with different residual stroma bed in rabbits

目的研究不同切削量的准分子激光原位角膜磨镶术(laserin situkeratomileusis,LASIK)后6个月角膜明胶酶MMP-2,MMP-9的表达,以探讨LASIK手术的切削深度不同对角膜的胶原结构的影响。方法选取成年新西兰白兔16只(32眼)随机分成A(n=8,正常对照组)、B、C、D四个组。B、C、D组分别行LASIK手术使残留的基质床厚度为整体角膜厚度的70%、50%、30%。术后6个月行明胶酶谱法检测角膜组织的明胶酶活性。结果术后6个月各组角膜组织均有明胶酶MMP-2(72 000,原酶)及MMP-2(62 000,活性酶)的表达,且各组相比差异均无统计学意义(F=2.273,P>0.05)。各组均无MMP-9(92 000,活性酶)的表达;且角膜地形图检测都没出现圆锥角膜或角膜后圆锥。结论单纯切削过量在LASIK术后6个月并未引起角膜主要胶原降解发生改变,也并非必然引起圆锥角膜。

Objective To study the influence of different residual cornea bed of laser in situ keratomileusis （LASIK）on collagen construction of cornea through investigating expression of MMP-2 and MMP-9 in cornea cell for different residual stroma bed after LASIK for six months. Methods Sixteen New Zealand white rabbits （32 eyes） were divided into four groups at random. Eight eyes in group A were controls. Rabbits in groups B, C and D were performed LASIK with residual stroma bed of the cornea 70 %, 50% and 30%, respectively. Activities of gelatinase of cornea tissue were detected by gelatin zymography after LASIK for six months. Results At 6 month after LASIK, MMP-2（72 000, resting enzyme）and MMP-2（62 000, active enzyme） were expressed in cornea cell in groups A,B,C,D, and there was no significant difference between four groups. MMP-9（92 000） was not expressed in four groups. At the same time, there was no keratoconus or posterior corneal conus on the corneal topography. Conclusion The single excess ablation of the stroma by excimer laser could not cause collagen degradation of cornea, and it is not consequential to cause keratoconus after LASIK for six months.