Improving the rehabilitation of patients with homonymous visual field loss using eye-tracking

Studentship Ref: SHLS2018001

Stroke is the main cause of acquired adult disability in high-income countries. Around 50% of those who survive a stroke suffer from visual field loss, most commonly homonymous visual field defects (HVFD). HVFD lead to considerable difficulties, particularly with visual exploration and page navigation which results in persistent and severe reading difficulties and impaired mobility. This significantly affects social functioning, mental health, and creates vision-specific dependency and a substantial reduction in health-related quality of life.
Current treatment methods for HVFD include: (i) restorative therapies, which aim at visual field restitution and (ii) compensatory therapies, which attempt to re-organize eye-movement control. While rigorously controlled trials that clearly establish the efficacy of any method are lacking, there is increasing evidence in favour of treatment protocols that involve the systematic and repetitive practice of specific eye movements.

Currently available methods for eye-movement training include: (1) individualised therapy developed empirically by clinicians (2) simple paper-based scanning exercises (3) apps or web-based training tools.

The main disadvantages, which all of these current methods have in common, are: (i) Objective quantification of any treatment effect is difficult or impossible to achieve. (ii) Patient feedback given by the clinician during the rehabilitation process is not objective as it depends on the clinician’s observations. (iii) Apps and web-based tools lack the controlled environment required to effectively monitor the user and provide meaningful feedback during the rehabilitation process.

Aims
The aims of the project are to:
- Adapt existing low-cost eyetracking technology for routine clinical use on patients with HVFD
- Develop interactive tools for the visual rehabilitation of HVFD
- Perform clinical testing of the visual rehabilitation tools on patients with HVFD
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Impact
Eye tracking will offer the potential to tailor the training regime to the individual patient based on scientifically established algorithms, rather than clinical experience. In addition, it will allow the evaluation of the efficiency of scanning training (see figure 1) and the use of low-cost video tracking technology means that the system has the potential to be used for in-office as well as a home training tool in the community.

Applicants require:
- Either a background in computing, physics, mathematics or similar and an interest to develop clinical research and data collection skills.
- Or a clinical background in a relevant discipline e.g. optometry, psychology, orthoptics etc. and an interest in computing and understanding of software development