Persistent Link:
http://hdl.handle.net/10150/194995
Title:
GDx-MM: An Imaging Mueller Matrix Retinal Polarimeter
Author:
Twietmeyer, Karen Marie
Issue Date:
2007
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:
Retinal diseases are a major cause of blindness worldwide. Although widely studied, disease mechanisms are not completely understood, and diagnostic tests may not detect disease early enough for timely intervention. The goal of this research is to contribute to research for more sensitive diagnostic tests that might use the interaction of polarized light with retinal tissue to detect subtle changes in the microstructure. This dissertation describes the GDx-MM, a scanning laser polarimeter which measures a complete 16-element Mueller matrix image of the retina. This full polarization signature may provide new comparative information on the structure of healthy and diseased retinal tissue by highlighting depolarizing structures as well as structures with varying magnitudes and orientations of retardance and diattenuation.The three major components of this dissertation are: 1. Development of methods for polarimeter optimization and error analysis; 2. Design, optimization, assembly, calibration, and validation of the GDx-MM polarimeter; and 3. Analysis of data for several human subjects. Development involved modifications to a Laser Diagnostics GDx, a commercially available scanning laser ophthalmoscope with incomplete polarization capability. Modifications included installation of polarization components, development of a data acquisition system, and implementation of algorithms to convert raw data into polarization parameter images. Optimization involved visualization of polarimeter state trajectories on the Poincaré sphere and a condition number analysis of the instrument matrix. Retinal images are collected non-invasively at 20 ?m resolution over a 15° visual field in four seconds. Validation of the polarimeter demonstrates a polarimetric measurement accuracy of approximately ± 5%.Retinal polarization data was collected on normal human subjects at the University of Arizona and at Indiana University School of Optometry. Calculated polarization parameter images reveal properties of the tissue microstructure. For example, retardance images indicate nerve fiber layer thickness and orientation, and depolarization images (uniform for these normal subjects), are predicted to indicate regions of disease-related tissue disruption. This research demonstrates a method for obtaining a full polarization signature of the retina in one measurement using a polarimetrically optimized instrument, and provides a step toward the use of complete retinal imaging polarimetry in the diagnosis and monitoring of retinal disease.
Type:
text; Electronic Dissertation
Keywords:
polarimetry; retinal disease
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Chipman, Russell A
Committee Chair:
Chipman, Russell A

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleGDx-MM: An Imaging Mueller Matrix Retinal Polarimeteren_US
dc.creatorTwietmeyer, Karen Marieen_US
dc.contributor.authorTwietmeyer, Karen Marieen_US
dc.date.issued2007en_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.abstractRetinal diseases are a major cause of blindness worldwide. Although widely studied, disease mechanisms are not completely understood, and diagnostic tests may not detect disease early enough for timely intervention. The goal of this research is to contribute to research for more sensitive diagnostic tests that might use the interaction of polarized light with retinal tissue to detect subtle changes in the microstructure. This dissertation describes the GDx-MM, a scanning laser polarimeter which measures a complete 16-element Mueller matrix image of the retina. This full polarization signature may provide new comparative information on the structure of healthy and diseased retinal tissue by highlighting depolarizing structures as well as structures with varying magnitudes and orientations of retardance and diattenuation.The three major components of this dissertation are: 1. Development of methods for polarimeter optimization and error analysis; 2. Design, optimization, assembly, calibration, and validation of the GDx-MM polarimeter; and 3. Analysis of data for several human subjects. Development involved modifications to a Laser Diagnostics GDx, a commercially available scanning laser ophthalmoscope with incomplete polarization capability. Modifications included installation of polarization components, development of a data acquisition system, and implementation of algorithms to convert raw data into polarization parameter images. Optimization involved visualization of polarimeter state trajectories on the Poincaré sphere and a condition number analysis of the instrument matrix. Retinal images are collected non-invasively at 20 ?m resolution over a 15° visual field in four seconds. Validation of the polarimeter demonstrates a polarimetric measurement accuracy of approximately ± 5%.Retinal polarization data was collected on normal human subjects at the University of Arizona and at Indiana University School of Optometry. Calculated polarization parameter images reveal properties of the tissue microstructure. For example, retardance images indicate nerve fiber layer thickness and orientation, and depolarization images (uniform for these normal subjects), are predicted to indicate regions of disease-related tissue disruption. This research demonstrates a method for obtaining a full polarization signature of the retina in one measurement using a polarimetrically optimized instrument, and provides a step toward the use of complete retinal imaging polarimetry in the diagnosis and monitoring of retinal disease.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectpolarimetryen_US
dc.subjectretinal diseaseen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorChipman, Russell Aen_US
dc.contributor.chairChipman, Russell Aen_US
dc.contributor.committeememberSasian, Jose M.en_US
dc.contributor.committeememberHua, Hongen_US
dc.identifier.proquest2396en_US
dc.identifier.oclc752261168en_US
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