Circuito óptico e metodologia para caracterização de lentes intraoculares

Abstract

This paper presents the development of an optical circuit and an innovative methodology for characterization of intraocular lenses (IOLs), currently indicated for the replacement of the crystalline lens, especially in the treatment of cataracts. The optical circuit uses a Hartmann-Shack type wavefront sensor, consisting of a CCD camera and a microlens array attached to it to replace the objective lens. The characterization process aims to quantify IOL optical aberrations using Zernike Polynomials, forming an orthogonal basis in which each basis function determines a specific aberration. The results of the characterization process discussed here have more comprehensive information on IOLs, which are usually overlooked by manufacturers. To calibrate the wavefront sensor, an alternative calibration procedure was developed. An innovative methodology is also proposed for IOL characterization based on ANSI Z8030 standard, through the development of an inexpensive experimental setup, in comparison to commercial equipments for this purpose. The great advantage of this methodology is to simplify the procedure described in the standard, allowing a complete IOL characterization by a single measurement. IOL samples with known manufacturing parameters, and previously characterized by a commercial equipment, were submitted to the characterization procedure developed in this study. Experimental testing has achieved similar results to those presented by the commercial equipment, proving that our optical circuit and that the new methodology can be a very effective and a more complete alternative for IOL characterization.