Design, validation and application of an ocular Shack-Hartmann aberrometer

Persistent Link:
http://hdl.handle.net/10150/289957
Title:
Design, validation and application of an ocular Shack-Hartmann aberrometer
Author:
Straub, Jochen
Issue Date:
2003
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The design and testing of an ocular Shack-Hartmann aberrometer is presented. The aberrometer objectively measures optical aberrations in the human eye in vivo. The sensor was successfully tested for measurements of refractive error (sphere and cylinder) and spherical aberration. Vignetting limits the measurement range of the wavefront to a range of -10 D to +15 D. Large refractive errors and decentration of the measurement induce aberrations in the test wavefront. Analytical tools to correct for these systematic errors were developed. A clinical study was conducted assessing visual performance in 158 eyes of 89 subjects before and after LARK refractive surgery. The main results of the study were that refractive surgery corrects refractive errors very accurately. A slight regression in refraction during the 12 months after surgery was noted. Measurements of ocular aberrations using the Shack-Hartmann aberrometer revealed that refractive surgery introduced large amounts of higher order aberrations, mainly spherical aberration and coma. The amount of aberrations changed significantly during the 12 months wound healing period. The dark adapted pupil diameter of the eye increased significantly during the first 6 months after surgery. The changes in ocular aberrations and pupil diameter were correlated to changes in contrast sensitivity in the human eye. The analysis of corneal topography showed that while the anterior corneal curvature changed due to surgery, we also saw a change in the posterior corneal curvature as a biomechanical response to surgery. A Customized Eye Model was designed and tested based on the clinical measurements. The model used conic surfaces and modeled defocus and spherical aberration. This computer eye model was then used in optical lens design software to calculate an optimal Customized Ablation Pattern for individual eyes.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Health Sciences, Ophthalmology.; Health Sciences, Medicine and Surgery.; Physics, Optics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Schwiegerling, James T.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDesign, validation and application of an ocular Shack-Hartmann aberrometeren_US
dc.creatorStraub, Jochenen_US
dc.contributor.authorStraub, Jochenen_US
dc.date.issued2003en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe design and testing of an ocular Shack-Hartmann aberrometer is presented. The aberrometer objectively measures optical aberrations in the human eye in vivo. The sensor was successfully tested for measurements of refractive error (sphere and cylinder) and spherical aberration. Vignetting limits the measurement range of the wavefront to a range of -10 D to +15 D. Large refractive errors and decentration of the measurement induce aberrations in the test wavefront. Analytical tools to correct for these systematic errors were developed. A clinical study was conducted assessing visual performance in 158 eyes of 89 subjects before and after LARK refractive surgery. The main results of the study were that refractive surgery corrects refractive errors very accurately. A slight regression in refraction during the 12 months after surgery was noted. Measurements of ocular aberrations using the Shack-Hartmann aberrometer revealed that refractive surgery introduced large amounts of higher order aberrations, mainly spherical aberration and coma. The amount of aberrations changed significantly during the 12 months wound healing period. The dark adapted pupil diameter of the eye increased significantly during the first 6 months after surgery. The changes in ocular aberrations and pupil diameter were correlated to changes in contrast sensitivity in the human eye. The analysis of corneal topography showed that while the anterior corneal curvature changed due to surgery, we also saw a change in the posterior corneal curvature as a biomechanical response to surgery. A Customized Eye Model was designed and tested based on the clinical measurements. The model used conic surfaces and modeled defocus and spherical aberration. This computer eye model was then used in optical lens design software to calculate an optimal Customized Ablation Pattern for individual eyes.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectHealth Sciences, Ophthalmology.en_US
dc.subjectHealth Sciences, Medicine and Surgery.en_US
dc.subjectPhysics, Optics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSchwiegerling, James T.en_US
dc.identifier.proquest3107043en_US
dc.identifier.bibrecord.b44666950en_US
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