Finite element models for computer simulation of intrastromal photorefractive keratectomy

Abstract

The main idea to correct sight disorders using lasers is to modify corneal curvature by applying laser to specific layers of the cornea. Intrastromal photorefractive keratectomy (ISPRK) is a laser technique used to correct sight disorders by evaporating corneal tissue from the stroma. Evaporating such tissue produces small cavities that may coincide to form a larger cavity. The composed big cavity is assumed to collapse to deform the overall curvature of the cornea. In this work, we provide finite element models to simulate the ISRPK procedure using a three-dimensional (3D) model of the cornea with typical parameters. The model outcome was compared with an earlier 2D model used for the same purpose, so as to determine its accuracy. In addition, a 3D finite element simulation of the procedure was made for a virtual astigmatic case to visualize the corneal curvature change. The results of this work show that this finite element models provide an accurate simulation of the corneal deformation expected after performing the procedure. © 2011 World Scientific Publishing Company.