Modeling intrastromal photorefractive keratectomy procedures

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 is a laser technique used to correct sight disorders by evaporating corneal tissue, which results in small cavities that may coincide to form a larger cavity that will collapse to deform the curvature of the cornea. In this work, a 3D finite element model of the cornea was designed with typical parameters to simulate the procedure. The model outcome was compared with an earlier 2D model used for the same purpose, so as to determine its accuracy. Finally, a 3D finite element simulation of the procedure was made for a virtual astigmatic case, so as to visualize the corneal curvature change. The results of this work show that this finite element model is relatively accurate for modeling the corneal deformation after performing the procedure. © 2008 IEEE.