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Title: Perceptual visual distortions in human amblyopia
Author: Piano, Marianne Emma Florence
ISNI:       0000 0004 5372 9313
Awarding Body: Glasgow Caledonian University
Current Institution: Glasgow Caledonian University
Date of Award: 2014
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It has been shown that adults and children with amblyopia can experience metamorphopsia (perceptual visual distortions). This body of work chronicles the piloting of a novel dichoptic technique to quantitatively map perceptual visual distortions in adults with amblyopia. It was demonstrated that perceptual visual distortions as measured with this method were more severe in strabismic amblyopes, were not homogenous across the visual field, and were highly individual to each amblyope, in common with the findings of other studies using alternative distortion mapping methods. It was established that perceptual visual distortions in adult amblyopes remained stable geotopically and in magnitude over time, and were closely associated with the angle of strabismic deviation and strength of binocular single vision - unique findings not documented in the literature previously. The dichoptic paradigm was then used to measure perceptual visual distortions in children with amblyopia at different stages of amblyopia treatment, as no study before had attempted to relate severity of perceptual visual distortions to amblyopia treatment outcomes, or establish how prevalent they were amongst amblyopic children. For the first time, a large sample of amblyopic children was tested (n = 82) and compared to agematched visually normal controls (n = 140). It was established that 56.1% of the sample had perceptual visual distortions, and importantly, that the severity of these was independent of amblyopia treatment outcomes. Instead, as in the adult amblyopes, distortion severity was found to be primarily dictated by strength of binocular function and the size of the angle of deviation. Overall, the key message of this work is the importance of evaluating all aspects of the disruption to visual function in amblyopia, and attempting a unified, binocular treatment approach that addresses these aspects, in the hope of producing better amblyopia treatment outcomes for children in the future.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available