Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574326
Title: An investigation of visual field test parameters in glaucoma, patterns of visual field loss in diabetics and multispectral imaging of the optic nerve head in glaucoma
Author: Wang, Yanfang
Awarding Body: University of Manchester
Current Institution: University of Manchester
Date of Award: 2013
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Abstract:
Visual field tests are routinely used for the detection and management of glaucoma. This thesis focuses on monitoring the vigilance during perimetry with pupil dynamics (pupillary movements, blinks) in glaucoma patients and the performance of using subsets of standard test patterns at detecting glaucomatous field loss. It describes the spatial pattern of visual field changes in diabetic retinopathy patients after treatment and the usage of multispectral imaging of the optic nerve head in glaucoma patients.The first investigation evaluated the use of pupillary parameters (pupil size and amplitude of pupillary oscillations) to monitor vigilance during perimetry in comparison to electroencephalography. A significant correlation was observed between the decreased pupil size and increased slow brain activities (theta and alpha). The inter-test threshold variability correlated with the pupil miosis.Another investigation explored blinks during a perimetric test and their relationship to the variability of threshold sensitivity in glaucoma patients. A wide range of blink frequencies was observed in glaucoma patients during perimetry and the timing of blinks was correlated with the stimuli presentations when they were supra-threshold. No significant relationship was observed between the threshold sensitivity variability and blink parameters (frequency, duration and microsleep numbers).The third investigation evaluated the use of subset of the 24-2 visual field test pattern at detecting glaucomatous field loss. A high sensitivity and specificity was observed when using subsets of the 24-2 pattern and test locations optimized by the positive predictive values showed a better performance than the test locations in random sequences.With the usage of a self-organized mapping method, nine spatial patterns of visual field loss in untreated diabetic retinopathy patients were classified. After laser treatment, a significant improvement on the spatial patterns of field loss and global indices was found.In the multispectral imaging study, the haemoglobin dependent differential light absorption (DLA) properties of the glaucomatous optic nerve head was evaluated with multispectral imaging. Change of DLA after medical hypotensive treatment was graded by five experts and no difference was observed in most of the patients.
Supervisor: Henson, David Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.574326  DOI: Not available
Keywords: glaucoma ; visual field ; vigilance ; blinks ; multispectral imaging ; optic nerve head
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