Binocular vision, visual function and pupil dynamics in people living with dementia

Overview

People with dementia experience difficulties coping with visual issues. Problems with binocular vision (using the eyes together) can lead to double vision, headaches and sore eyes and coupled with a loss of depth perception can increase the risk of falls and make hand-eye coordination tasks harder. Such problems are remedied with simple treatments, yet testing for this is not included in current dementia friendly eye test guidelines.

Depth perception problems are common in Alzheimer's disease and other forms of dementia, but no study to date has found out how often these problems occur. It’s unknown whether they interact with other eye-related markers of dementia, such as changes in the pupil, or letter chart vision, or if changes in these over time match the changes in memory and brain structure or function.

Dr Coleman aims to find out how common binocular vision problems and pupil changes are in people with recently-diagnosed dementia. The relationship between changes in binocular vision, pupils, level of letter chart vision, and memory test scores over time will be examined to determine whether changes are related to changes in brain structure, or activation of brain areas used in vision for people with Alzheimer's disease.

240 people recently diagnosed with dementia (within the last 12 months) will be invited to have an eye check-up. They will play an easy 3D game and look at a computer screen while trying to remember a few numbers, and do a memory test. 30 people with Alzheimer's disease will have an MRI scan. Everybody will be retested twice, four months apart. People who had a MRI scan will have a second scan just before/after the last check-up. Significant changes between visits in: letter chart vision, binocular vision, pupil responses, memory test scores, brain structure, and activation of brain areas used in vision will be observed. A calculation will be performed to determine how common depth perception and binocular vision problems are in the group.

This project will show how often people with dementia experience binocular vision problems. If they are frequent, diagnosing/treating them could improve the quality of life for those affected. This research will show whether changes in depth perception, pupil responses and quality of vision relate to changes in memory, and brain structure/function. If they are related, these quick and non-invasive eye-tests will help to monitor dementia. This would justify whether binocular vision and pupil response testing should be included in dementia-friendly eye-testing guidelines.