City Research Online

Abstract

Static automated perimetry of the central 30˚ is the most often used visual field 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, balance and mobility.

An efficient standard automated examination for the peripheral visual field has not been established yet. This thesis aims to lay groundwork for the development of such a test. I introduce a kinetic automated test, which estimates an isopter with three repeated presentations per meridian. I ask whether measuring a peripheral isopter adds information to central visual field test results, investigate retest reliability and evaluate the efficiency of test procedures with repeated presentations through computer simulations. Moreover, I investigate how visual field thresholds obtained with static and kinetic stimuli relate to each other and examine the influence of stimulus sizes III and V on static threshold estimates. I also investigate the relationship between response variability and contrast sensitivity in the peripheral visual field.

Based on the results, I suggest using repeated presentations in automated kinetic tests. I demonstrate that data driven computer simulations are useful for the development of efficient automated kinetic perimetry. The frequency-of-seeing results suggest that response variability to static stimuli in the far periphery is lower than suggested by previous data (Henson et al., 2000). This is relevant to future computer simulations of peripheral visual field tests with static automated perimetry. As a future avenue for examining the visual field periphery I propose a combined static kinetic automated visual field test, which combines a peripheral isopter as a region of interest with static stimuli inside this region.

In a separate investigation, I examine the influence of visual field damage on reading performance and evaluate the relationship between reading performance and eye movements, using a within-patient between-eye study design in glaucoma patients with asymmetrical visual field loss. Between-eye reading performance was affected by visual field loss and co-occurred with specific eye movement patterns. The within-patient between-eye design appeared to be useful for investigating the relationship between visual field loss and functional disability.

Publication Type:	Thesis (Doctoral)
Subjects:	R Medicine > RE Ophthalmology
Departments:	School of Health & Psychological Sciences > Optometry & Visual Sciences Doctoral Theses School of Health & Psychological Sciences > School of Health & Psychological Sciences Doctoral Theses

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