基于有限元的角膜建模及RK手术分析

放射状角膜切开术简称RK手术，是通过改变角膜的屈光度矫正视力的一种方法。这种手术简单，疗效显著，受到普遍欢迎，但手术前后应力分布及术中参数变化对手术的影响一直是医患双方共同关心的问题。以有限元软件ANSYS为工具，分别建立眼角膜RK手术前后的有限元模型，并在此基础上对比分析手术前后眼角膜的应力分布、眼内压对角膜的影响及RK手术中切口深度对整个手术效果的影响。仿真结果显示：正常情况下的角膜应力主要分布在水平边缘方向。RK手术后的刀口两端有明显的应力集中现象；RK手术中随着切口深度的增加，角膜曲率半径的变化会变大，对近视的矫正效果也越好，但术后风险会加大。

Corneal Modeling Based on Finite Element and RK Analysis

The radiate keratotomy, briefly called as RK, is a method to rectify visual acuity through changing corneal diopter. This operation is easy and popular, and has great effect, however, the influence of stress distribution before and after operation as well as the parameter change on operation are always the problems concerned both by doctors and patients. Taking finite element software ANSYS as the tool, it separately builds up the finite element modeling before and after corneal RK, and based on it, it makes contrast and analysis on the stress distribution of cornea before and after operation, the influence of intraocular pressure on cornea, and the influence of cut depth on the effect of entire RK. The simulation result shows： in the normal situation, the corneal stress is mainly distributed on the level edge, and after RK, two ends of blade appear the obvious stress centralization; during RK, with the increase of cut depth, the corneal curvature radius changes greater and greater, and the rectifying effect for myopia becomes better, but the risk after operation becomes larger.