Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 40 for “"RE Ophthalmology"”.
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The multifocal visual evoked cortical potential in visual field mapping: a methodological study.
… visual evoked cortical potential (mfVECP) presents several technical challenges. Signals are small, are influenced by a number of sources of noise and waveforms vary both across the visual field and between subjects due to the complex geometry of the visual cortex. Together these factors …
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Trends and health economic aspects of service delivery of glaucoma
… group of optic neuropathies characterised by progressive irreversible loss of visual function. Within this thesis, a health economic model was constructed to map service provision from diagnosis considering two competing strategies: the current practice of annual visual field (VF) monitoring …
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Studies on real world visual field data in glaucoma
… is a leading cause of blindness. As a progressive condition, it is important to monitor how the visual field (VF) changes over time with perimetry in preventing vision from deteriorating to a stage where quality of life is affected. However, there is little evidence of how clinical …
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Studies of normal and deficient colour vision with relevance to occupational environments
… colour vision in visually demanding, colour-related tasks that are often safety-critical and aim to improve our understanding of how congenital deficiencies can affect the processing of colour signals and the corresponding changes in visual performance. The first study compares the colour …
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Reclaiming the periphery: Kinetic perimetry in patients with glaucoma
… test in glaucoma patients. Short test durations are achieved by focusing on a central region, which constitutes ~20% of the visual field. However, ignoring the periphery may sacrifice information on how patients are affected functionally. Peripheral vision is important for guiding attention, …
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Investigation of plenoptic imaging systems: a wave optics approach
Conventional imaging devices only capture a part of the total information carried by the light. A new generation of imaging devices, plenoptic systems, use an array of micro lenses to codify the light coming from an object into a four dimensional function called the light field. The final image is …
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A study of mechanisms for discomfort glare
The presence of a bright light source in the visual field, particularly when viewed against a dark background, can generate a form of discomfort, which is often described as ‘discomfort glare’. The mechanisms for discomfort glare remain poorly understood, even after 50 years of multidisciplinary …
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Ethnic differences in the spatial distribution of macular pigment and its association with foveal anatomy
Macular pigment (MP) at the centre of the retina is thought to serve a protective function shielding the photoreceptors from damaging effects of blue light. The amount of MP and its spatial density distribution across the macula i.e. its spatial profile varies among individuals. Lower levels of MP …
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Spatial and temporal aspects of visual performance in relation to light level and normal aging
The research contained in this thesis describes three studies designed to investigate the ability of the observer to detect stimuli defined by changes in luminance in space and/or time in mesopic conditions, including contrast sensitivity, temporal flicker sensitivity and visual acuity. The first …
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Glistenings in Intraocular lenses and their effect on forward light scatter; an in vitro study
Introduction. Glistenings are fluid-filled inclusions in the polymer matrix of an intraocular lens (IOL). Acting as refractile particles they may contribute to a reported high level of forward light scatter. However, several studies have reported that there is no significant correlation with a …
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Understanding disability glare: the effects of scattered light on visual performance
The focus of this thesis is on how light is scattered on its passage through the optics of the human eye, and the consequences for visual performance under different lighting conditions. A number of visual psychophysical measurement techniques were employed to investigate the impact of light …
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The friction coefficient of soft contact lens surfaces in relation to comfort and performance
The soft contact lenses of today are made from a variety of hydrogel materials. These materials have different properties in terms of water content, monomers, hardness and other tensile characteristics. It is likely that the frictional properties also vary between materials. It is known that …
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A quantitative analysis of eye movement characteristics during the cover test
… test of oculomotor status. It is surprising therefore, that there has been only one previous study which has attempted to provide a quantitative analysis of the eye movements during the test. There is also a dearth of information concerning the relationship between eye movements during the cover …
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Variability of chromatic sensitivity: fundamental studies and clinical applications
This investigation involved a number of related studies with the principal aim of assessing the variability in chromatic sensitivity in "normal" trichromats and colour deficient observers. An important outcome was the development of a new method for accurate and efficient measurement of chromatic …
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A study of the role of advanced technologies in glaucoma case-finding
… 11,000 new cases of open angle glaucoma (OAG) are diagnosed annually in people aged 40 to 70 years. However, two--‐thirds of UK OAG cases may remain undiagnosed, highlighting the need for improved detection. UK optometrists generate more than 95% of referrals for suspected glaucoma and ocular …
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Improving the detection of correctable low vision in older people
In the UK, 20-50% of older people have undetected reduced vision and in most of these cases the poor vision can be readily corrected by new spectacles and/or cataract surgery. It is often assumed that older people with vision loss will have regular eye examinations so that these problems can be …
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An Evidence-Based Investigation of the Content of Optometric Eye Examinations in the UK
A literature review revealed a lack of systematic research investigating standards of clinical practice within optometry. Three main approaches have been used to evaluate the content of clinical consultations: abstraction of clinical records, clinical vignettes and unannounced standardised …
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A study of pupil response components in human vision
The overall aim of the research described in this thesis was to investigate the basic mechanisms of the pupil of the eye in relation to human vision and brain function. It also evaluates the potential application of new research techniques to clinical studies that involve assessment of the visual …
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