The Efficacy of Visuomotor Compensatory Training for Individuals with Visual Field Defects

Abstract

Several approaches have been developed to help patients with partial visual field defects to cope with their visual loss, and the most effective are those that encourage the person to move their eyes more efficiently. This thesis sought to examine the efficacy of a multiplatform compensatory training called Durham Reading and Exploration (DREX) in the rehabilitation of these individuals. Overall, the thesis focuses on two primary aims which include establishing whether the DREX training app completed on either a computer or a touchscreen tablet can be an effective treatment for homonymous visual field defects (HVFDs) caused by brain injury, as well as validating the assessment tasks that have been incorporated into the app. The results from Studies 1 to 3 show that DREX training is clinically effective for HVFD rehabilitation, and the training effect in patients trained using a touchscreen tablet is equivalent to patients trained with a computer, with a meaningful improvement in the quality of life which remains stable over a period of three months. In Studies 4 to 6, the built-in assessments tasks are found to be reliable and valid and can be used confidently to monitor the training progression and outcomes. Study 7 explores the novel observation that DREX training is also beneficial for patients with other types of partial visual field defects like tunnel vision and central visual field loss, demonstrating that this training could potentially be offered to a wider low vision population. Finally, studies 8 and 9 explore whether the blurring of vision, a common comorbid visual impairment in patients with visual field defect, could affect the visual exploration performance and the outcomes of visual exploration training. From these results it is clear that blurring of vision did reduce the search efficacy, but searching behaviour can still be improved with the training. Taken together, the findings from this suite of studies indicate that DREX is an effective and inexpensive treatment for visual field defects in a variety of etiologies, however the comorbid impairments that could affect the rehabilitation should be identified to maximise efficacy of this treatment.