Medida de la respuesta acomodativa con un sistema de doble paso: aplicación al estudio de la acomodación en función de la edad.
- Autores: Mikel Aldaba
- Directores de la Tesis: Montserrat Arjona Carbonell (dir. tes.), Jaume Pujol Ramo (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2012
- Idioma: español
- Tribunal Calificador de la Tesis: Santiago Mar Sardaña (presid.), Susana Marcos Celestino (secret.), Pablo Artal Soriano (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Accommodation, defined as the dioptric change of the eye, enables clear vision at different distances. Its study is interesting due to different aspects: the progressive loss of amplitude of accommodation known as presbyopia, the recent interest in accommodative restauration techniques in pseudophakic patients, its possible relation to myopia development and the associated pathologies. The most widely used techniques to measure accommodation are the subjectives, although it has been shown that they overestimate accommodation due to pseudoaccommodation. There are also several objective techniques as retinoscopy, autorefractometers or aberrometers. In the last years it has been suggested that a more realistic accommodative measurement is done when all the aberrations of the eye are taken into acount, and not just defocus. The goal of this thesis has been to develop a method based on the double pass technique for the accommodative response measurement and its application to the study of accommodation with age. Double pass technique is based on projecting a point source on the retina and recording images after retinal reflection and double pass through the ocular media. This technique provides information about the optical quality of the eye and takes into acount all the factors influencing the retinal image quality, thus it is ideal for being applied in the measurement of tha accommodative response. In the first part of the thesis the method for the accommodative response measurement based on double pass technique has been developed and it has been validated by comparison with Hartmann-Shack measurements. The developed experimental setup combines both techniques, double pass and Hartmann-Shack, and it is specifically designed for accommodative response measurements, including elements like the open field fixation test that allows a more natural accommodative stimulation. The method developed is based on finding the vergence that maximizes the quality of the double pass image. Several double pass images are recorded by means of an axial scanning and the vergence of the best double pass image is related to accommodative response. Double pass measurements showed a good agreement with Hartmann-Shack measurements and no statistically significant differences, thus validating our method. In the second part of the thesis, the method has been applied for the study of the accommoditve response in a wide age range population. The accommodative response measured in young patients was higher than the published in the literature, due to our measurements being based on the retinal image quality and not on defocus. While in older patients, the accommodative response measurements are in good agreement with previous works. The accommodative stimulus-response curve and its slope also showed a worsening with age, with a more noticeable change in the accommodation after the age of 35-40 years. The work done during the thesis led to articles in journals and several contributions to congresses, as well as to a patent being comercially exploited.
