Mechanical Analysis of the Excimer Laser Photorefractive Keratectomy

ABSTRACT

This study proposed a mechanical model of the excimer laser photorefractive keratectomy(PRK) for myopia patients utilizing finite element method, which is a simulation technique widely used in engineering fields. The outcomes of the surgery depends on many factors, which are also dependent on each other. In this study, some mechanical factors are selected and the effects of the selected factors on the surgical results were analyzed. One of the important factors in the finite element analysis is the mechanical properties of the object. The representative characteristic of the human cornea is that it shows highly nonlinear property in the stress-strain relationship like most soft tissues in the human body. Therefore, the nonliear property was adopted in this study. Other important mechanical properties which affect the outcomes of the surgery are a preoperative thickness, intraocular pressure, diameter of ablation zone and the depth of ablation. With various changes of the those mechanical factors, the outcomes of the surgery were predicted using the finite element method. The results show the qualitative agreement with clinical outcomes also promising agreement quantitatively. Therefore, this study shows a potential of the finite element method in clinical application of excimer laser PRK.