Wavefront Analysis of Crystalline Lenses Using a Hartman-Shack Aberrometer and Videokeratoscope

Abstract

Abstract: : Purpose: To establish a method for analyzing aberrations of crystalline lenses and determine the accuracy of the method. Methods: By inversely propagating the rays obtained using a Hartman-Shack aberrometer at the front of the crystalline lenses using a computer ray tracing method and determining the corneal topography using a videokeratoscope, the wavefront in front of the crystalline lens was calculated and the aberration was analyzed by Zernike polynominals. The accuracy of applying this method to the eye with an intraocular lens (IOL) and a normal cornea was evaluated. Results: The proposed method was established by using an adequate index of the cornea and anterior chamber (840 nm) and an approximation of the fourth-order xnym polynomial for the topography of the corneal center. The calculated mean power of the IOL was nearly equal to the value provided by the IOL manufacturer. The prism component in the wavefront then was detected, resulting from the tilt and/or decentration of the IOL. Conclusions: The method of wavefront analysis of crystalline lenses using a Hartman-Shack aberrometer and a videokeratoscope was established and the accuracy of the method was confirmed. The method is clinically useful to objectively evaluate the visual function of crystalline lenses.

Keywords: crystallins • optical properties • physiological optics