Desarrollo de nueva instrumentacion para la medida de la calidad optica del ojo

Abstract

The sense of sight plays a crucial role in the relation of the human being with his environment, proportioning most of the information that he perceives from it. So the importance of the study of the quality of the eye as an imaging system is understandable. This study is clinically carried out by means of subjective measurements, or more recently, by the determination of the ocular wave aberration. However, there is a lack of clinical tools for the evaluation of ocular optical quality taking into account all the factors degrading the image on the retina (difraction, aberrations and intraocular scattering). Thus, the main objective of this thesis work consists of the development of a clinical instrument for the measurement of the eye's overall optical quality, based on the double-pass technique, complementing those measurements with aberrometric estimations. Therefore, the optical, mechanical and electronic design of a system based on the double-pass technique has been performed obtaining a totally automatized instrument prototype. A software tool has been implemented as well, permiting the control of the device, the register and analysis of the images, and the visualization of the results in a very simple way. It gives the user both qualitative and quantitative information (by means of the modulation transfer function MTF and several quality parameters) about the optical performance for far vision and different accommodative states. In this sense a method for the determination of the amplitude of accommodation has been developed making this instrument the only system capable of objectively measuring this magnitude. The instrument has been clinically validated. A second prototype has also been implemented that permits the analysis of the repetitiveness of the system's results. Additionally, two separate clinical studies have been carried out that demostrate the instrument's potential. In the first study, a method for estimating psicophysical parameters (visual ac