【摘要】 目的用准分子激光对兔眼角膜进行切削,改变角膜的厚度。研究在离体状态下兔眼角膜生物力学特性在不同厚度与眼压状态下的变化。方法健康新西兰大白兔15只30眼。分3组,1组:正常组,未切削眼;2组:切削原角膜厚度的1/3;3组:切削原角膜厚度的1/2。自制夹具固定角膜,通过连通器对角膜内表面加压。每个压力状态下三维激光扫描仪扫描。分析在不同压力状态下不同角膜厚度时角膜前凸的变化。实验数据用SPSS13.0统计软件进行方差分析。结果各眼压与初始眼压状态下角膜凸出度的差值dx-1(0x=20～80)转化成logd1,3组比较:3组与1组和2组差异均有统计学意义(P<0.05)。1组和2组差异无统计学意义(P>0.05)。相邻眼压的角膜凸出度的差值d(x+10)-x(x=10～70)转化成logd2,3组比较差异无统计学意义(P>0.05)。结论术后角膜的前凸与生物力学改变有关。为了确保屈光手术的安全性和稳定性,剩余角膜基质床厚度不应小于原始角膜厚度的1/2,同时眼压应维持在正常范围的低限。更多还原

【Abstract】 【Objective】In ex vivo to research biomechanical changes in the cornea of rabbits after excimer laser incision as would be performed in laser in situ keratomileusis (LASIK).To develop a relation among the corneal biomechanical property of rabbits and the central corneal thickness (CCT) and the intraocular pressure (IOP).【Methods】A total of thirty eyes of fifteen New Zealand rabbits were internalize in the study.Ten eyes were incise 1/3 primal corneal thickness and ten eyes were incise 1/2,the other ten were control.The corneal sample was put on the clamping apparatus.To pressurize by cross-connection device and scan with three dimensional laser scanning.To analyze changes of corneal forward shift of the sample under different IOP and CCT.All the parameters were con-vert into logarithm,then the measurement data were evaluate using variance analysis.【Results】The differences of corneal protrusion dx-10 (x=20～80)(logd1)under three groups of every experimental pressure and primary pressures are as below:the differences of ablation1/2 group with normal group and ablation1/3 group are statistically meaning-ful.The differences of normal group with ablation 1/3 group are statistically meaningless.The differences of corneal protrusion d (x+10)-x (x=10～70) (logd2) under adjacent pressures are statistically meaningless in the three groups.【Conclusion】The change of corneal biomechanics has some relationship with post-LASIK keratectasia.The post-LASIK keratectasia has some relationship with thickness and pressure.To insure the stability and security of LASIK,the residual corneal stroma-bed thickness must more than half primary thickness,and IOP should be main-tain at the lower level in normal IOP.更多还原