Optical aberrations in ametropic eyes and their change with corneal refractive surgery

In this thesis the laser ray tracing (LRT) technique for measurement of ocular aberrations has been implemented, validated and applied, in conjunction with complementary techniques, to the study of ocular aberrations in human eyes. In particular, we studied optical aberrations in myopic and hyperopi...

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Detalles Bibliográficos
Autor: Llorente, Lourdes
Tipo de recurso: tesis doctoral
Fecha de publicación:2009
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/18906
Acceso en línea:http://hdl.handle.net/10261/18906
Access Level:acceso abierto
Palabra clave:physiological optics
Ocular aberrations
laser ray tracing
longitudinal chromatic aberration
near infrared
polarisation
Birefringence
sampling pattern
spherical aberration
Coma
Corneal aberrations
myopia
hyperopia
Axial length
corneal shape
emmetropisation
presbyopia
LASIK
Asphericity
corneal ablation
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spelling Optical aberrations in ametropic eyes and their change with corneal refractive surgeryLlorente, Lourdesphysiological opticsOcular aberrationslaser ray tracinglongitudinal chromatic aberrationnear infraredpolarisationBirefringencesampling patternspherical aberrationComaCorneal aberrationsmyopiahyperopiaAxial lengthcorneal shapeemmetropisationpresbyopiaLASIKAsphericitycorneal ablationIn this thesis the laser ray tracing (LRT) technique for measurement of ocular aberrations has been implemented, validated and applied, in conjunction with complementary techniques, to the study of ocular aberrations in human eyes. In particular, we studied optical aberrations in myopic and hyperopic eyes and the optical changes induced by refractive surgery for myopia and hyperopia. We have studied the impact of the optimisation of some experimental parameters on the estimation of the wave aberration. We demonstrated that although the polarisation state and wavelength of the illumination light affected the intensity patterns of the images obtained using reflectometric aberrometry (LRT and Hartmann Shack sensor), these changes did not affect the estimation of aberrations. We also showed that the difference in the defocus term (focus shift) due to the use of different wavelengths is in agreement with the Longitudinal Chromatic Aberration of the Indiana Chromatic Eye Model for average normal eyes, although intersubject variability is not negligible. In addition, we studied experimentally the influence of the geometrical distribution and density of the pupil sampling on the estimation of aberrations using artificial and normal human eyes, and performed numerical simulations to extend our results to "abnormal"eyes. We found that the spatial distribution of the samples can be more important than the number of samples, for both our measured as well as our simulated "abnormal" eyes. Experimentally, we did not find large differences across patterns except, as expected, for undersampled patterns. We found that hyperopic eyes tended to have more positive asphericity and greater total and corneal spherical aberration than myopic eyes, as well as greater 3rd and higher order aberrations. Although we found no significant differences between groups in terms of internal aberrations, internal spherical aberration showed a significant age-related shift toward less negative values in the hyperopic group. We also assessed the impact of the LASIK corneal surgery, a popular surgical technique for correction of refractive errors, on the optical quality for both myopic and hyperopic standard techniques. Third and higher order ocular and anterior corneal aberrations increased with the surgery. Ocular and corneal spherical aberration changed towards more positive values with myopic LASIK, and towards more negative values with hyperopic LASIK. Changes in internal spherical aberration were of opposite sign than those induced in corneal spherical aberration. Changes induced by hyperopic LASIK were larger than those induced by myopic LASIK for a similar attempted correction.Peer reviewed200920092009info:eu-repo/semantics/doctoralThesishttp://purl.org/coar/resource_type/c_db068896430 bytesapplication/pdfhttp://hdl.handle.net/10261/18906reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglésinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/189062026-05-22T06:33:51Z
dc.title.none.fl_str_mv Optical aberrations in ametropic eyes and their change with corneal refractive surgery
title Optical aberrations in ametropic eyes and their change with corneal refractive surgery
spellingShingle Optical aberrations in ametropic eyes and their change with corneal refractive surgery
Llorente, Lourdes
physiological optics
Ocular aberrations
laser ray tracing
longitudinal chromatic aberration
near infrared
polarisation
Birefringence
sampling pattern
spherical aberration
Coma
Corneal aberrations
myopia
hyperopia
Axial length
corneal shape
emmetropisation
presbyopia
LASIK
Asphericity
corneal ablation
title_short Optical aberrations in ametropic eyes and their change with corneal refractive surgery
title_full Optical aberrations in ametropic eyes and their change with corneal refractive surgery
title_fullStr Optical aberrations in ametropic eyes and their change with corneal refractive surgery
title_full_unstemmed Optical aberrations in ametropic eyes and their change with corneal refractive surgery
title_sort Optical aberrations in ametropic eyes and their change with corneal refractive surgery
dc.creator.none.fl_str_mv Llorente, Lourdes
author Llorente, Lourdes
author_facet Llorente, Lourdes
author_role author
dc.subject.none.fl_str_mv physiological optics
Ocular aberrations
laser ray tracing
longitudinal chromatic aberration
near infrared
polarisation
Birefringence
sampling pattern
spherical aberration
Coma
Corneal aberrations
myopia
hyperopia
Axial length
corneal shape
emmetropisation
presbyopia
LASIK
Asphericity
corneal ablation
topic physiological optics
Ocular aberrations
laser ray tracing
longitudinal chromatic aberration
near infrared
polarisation
Birefringence
sampling pattern
spherical aberration
Coma
Corneal aberrations
myopia
hyperopia
Axial length
corneal shape
emmetropisation
presbyopia
LASIK
Asphericity
corneal ablation
description In this thesis the laser ray tracing (LRT) technique for measurement of ocular aberrations has been implemented, validated and applied, in conjunction with complementary techniques, to the study of ocular aberrations in human eyes. In particular, we studied optical aberrations in myopic and hyperopic eyes and the optical changes induced by refractive surgery for myopia and hyperopia. We have studied the impact of the optimisation of some experimental parameters on the estimation of the wave aberration. We demonstrated that although the polarisation state and wavelength of the illumination light affected the intensity patterns of the images obtained using reflectometric aberrometry (LRT and Hartmann Shack sensor), these changes did not affect the estimation of aberrations. We also showed that the difference in the defocus term (focus shift) due to the use of different wavelengths is in agreement with the Longitudinal Chromatic Aberration of the Indiana Chromatic Eye Model for average normal eyes, although intersubject variability is not negligible. In addition, we studied experimentally the influence of the geometrical distribution and density of the pupil sampling on the estimation of aberrations using artificial and normal human eyes, and performed numerical simulations to extend our results to "abnormal"eyes. We found that the spatial distribution of the samples can be more important than the number of samples, for both our measured as well as our simulated "abnormal" eyes. Experimentally, we did not find large differences across patterns except, as expected, for undersampled patterns. We found that hyperopic eyes tended to have more positive asphericity and greater total and corneal spherical aberration than myopic eyes, as well as greater 3rd and higher order aberrations. Although we found no significant differences between groups in terms of internal aberrations, internal spherical aberration showed a significant age-related shift toward less negative values in the hyperopic group. We also assessed the impact of the LASIK corneal surgery, a popular surgical technique for correction of refractive errors, on the optical quality for both myopic and hyperopic standard techniques. Third and higher order ocular and anterior corneal aberrations increased with the surgery. Ocular and corneal spherical aberration changed towards more positive values with myopic LASIK, and towards more negative values with hyperopic LASIK. Changes in internal spherical aberration were of opposite sign than those induced in corneal spherical aberration. Changes induced by hyperopic LASIK were larger than those induced by myopic LASIK for a similar attempted correction.
publishDate 2009
dc.date.none.fl_str_mv 2009
2009
2009
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
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format doctoralThesis
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/18906
url http://hdl.handle.net/10261/18906
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 8896430 bytes
application/pdf
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
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