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Title: Changes in spatial summation in response to intraocular pressure-lowering treatment in glaucoma : evidence of neural remodeling?
Author: Je, Shindy
ISNI:       0000 0004 7231 878X
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2017
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Recent studies of experimental glaucoma have suggested that retinal ganglion cells (RGCs) undergo a period of pre-morbid dysfunction, and there is some evidence that this may also occur in humans with glaucoma. A conceptual model by Porciatti & Ventura (2012) illustrates that reduced visual function owing to pre-morbid changes in RGCs may be recoverable in early disease with timely intraocular pressure-lowering treatment. In this thesis, pre-morbid dysfunction is investigated in glaucoma patients before, and 6 months after, trabeculectomy treatment with measures of spatial summation (specifically, Ricco's area, previously found to be larger in glaucoma patients than in healthy controls in visual field regions with very early damage). Controls were a cohort of patients with stable glaucoma, and age-similar healthy individuals. The hypothesis was that an already-enlarged Ricco's area would shrink in response to IOP-lowering treatment, while no between-visit change would be observable in the stable glaucoma and healthy control groups. A slight overall reduction in Ricco's area was found in those test locations with least baseline damage, but an overall enlargement was found in those with more moderate-advanced baseline damage. An initial study of Ricco's area in amblyopia, a condition in which the retinal receptive fields are understood to be normal, found that Ricco's area was larger than normal when measured through the amblyopic eye, and smaller than normal when measured through the non-amblyopic eye. This finding, together with findings described in published literature suggest a cortical origin for Ricco's area. Thus, it may be that in regions with early damage, recovery from dysfunction was observed, while in those with moderate-advanced damage, a cortical adaptation to cell death was observed. Finally, permutation of between-visit differences in Ricco's area and sensitivity to a Goldmann III stimulus indicates that the former has a relatively higher signal-to-noise ratio (SNR) for identifying change over time.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: RE Ophthalmology