Sistema de medidas automáticas de vícios de refração ocular. / Automatic measuring system of ocular refractive errors.

AUTOR(ES)
DATA DE PUBLICAÇÃO

1995

RESUMO

The purpose of the present work is the development of an objective and automatic system for ocular refractive errors measurements. Hence, a strong interaction between Physics and Ophthalmology was fundamentally important in order to provide the success of the work four systems have been developed, where three of them are completely different from each other in the sense of the basic principles used for determining the ocular ametropies, as well as for the detection of the scattered light from the retina. System four is just an improvement of system three, which has presented a good efficiency for clinical use purposes. The third and fourth systems, called DVL-1 and DVL-2 systems, consist on projecting a target in the fundus of the tested eye with a diod laser light. The beams which emerge from the tested eye are divided into six portions (three meridians) and are analyzed in pairs by a CCD (linear CCD for DVL-1 and matrix CCD for DVL-2). The distances between the two images in each meridian provide the refractive power in that particular meridian. As the refractive power is obtained for the three meridians (0°, 120° e 240°), it is possible to determine the ocular refractive error . Tests in artificial eyes have been done and an average error of 0,06di was obtained (0,125di is the allowed precision for this kind of examination). For measurements in vivo eyes a precision of 0,125di for spherical and cylindrical coordinates were obtained, as well as a 5° precision for the axis of astigmatism. These precision values are the ones required by the clinical evaluation.

ASSUNTO(S)

vícios de refração ocular auto-refrator auto-refractor ocular refractive errors

ACESSO AO ARTIGO

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