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Title: Aspects of ocular structural and functional assessment
Author: Robson, Catherine Ruth
ISNI:       0000 0004 2749 1495
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2006
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This thesis is a continuation of previous work within the Research Group and comprises an investigation of two perimetry-related topics; firstly, the role of ocular media properties on the visual field derived by Short Wavelength Automated Perimetry (SWAP); and, secondly, the perimetric assessment of patients with epilepsy treated with vigabatrin and the potential of alternative (imaging) techniques to overcome the subjective limitations of perimetry. The influence of ocular media adsorption and intra-ocular straylight on the visual field indices Mean Sensitivity, Mean Deviation, Pattern Standard Deviation and Short-term fluctuation derived by white-on-white (W-W) perimetry and by SWAP was investigated in 35 normal individuals. Approximately 62% of the variance for W-W perimetry was explained by the assessment of logMAR visual acuity in conjunction with a low contrast chart. However, no relationship was evident for SWAP. This suggests that ocular media properties are a component of the between-individual variability in SWAP but that their contribution is masked by other sources of variability. The prevalence of visual field loss associated with vigabatrin, (VAVFL), was investigated for 80 individuals with long-term exposure to vigabatrin (Mean duration 8.6 years SD3.5 and mean cumulative dose 7.6kg SD4.4). The prevalence was 62.5%; risk factors for VAVFL were treatment duration (p=0.001) and male gender (p=0.04). The ability of Optical Coherence Tomography (OCT) and confocal Scanning Laser Ophthalmoscopy (cSLO) to detect retinal damage in 21 patients exposed to VGB and 43 control patients (16 exposed to carbamazepine monotherapy, 7 exposed to sodium valproate monotherapy and 20 normals) was investigated. In patients with VAVFL, RNFL was attenuated but macular thickness was normal compared to the remaining individuals in the cohort.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available