Question: It’s been noted that, in addition to the impact on cognitive function, Alzheimer’s disease may also affect eye health. Could you elaborate on that?
Answer: First, it is important to mention that while connections between Alzheimer’s disease and eye health have been noted, they do not imply a causal relationship. The exact mechanisms underlying these associations are complex and require further research.
However, the link between eyes and Alzheimer’s has prompted researchers to investigate the potential of changes in ocular structure and function to serve as diagnostic biomarkers for identifying individuals at risk or for tracking the progression of the disease.
Studies have found that people with Alzheimer’s may show characteristic structural changes in the eye, such as thinning of the nerve fibre layer, changes in blood vessel density, and alterations in the size and shape of the optic disc. Imaging equipment such as optical coherence tomography (OCT) can detect and monitor such changes.
There may also be alterations to a person’s depth perception, contrast sensitivity, colour discrimination, and visual acuity, which can impact activities such as reading, recognizing faces, and navigating the environment.
Another functional impairment we might test for in the exam room is difficulty with smooth or rapid eye movements and maintaining focus on specific visual stimuli, which may affect the ability to track moving objects or follow a conversation out in the real world.
Though we have barely begun to scratch the surface, the diagnostic potential of retinal photography and OCT as noninvasive tools to identify signs of Alzheimer’s disease through changes in the eye long before the cognitive signs become apparent is an exciting area for further research.
In the future, timely detection of this disease could mean earlier interventions that can help enhance a person’s overall well-being.
The use of these modern imaging technologies, together with regular comprehensive assessments of visual function by your optometrist to monitor changes over time, will hopefully serve as one more way to maintain quality of life for anyone, including those living with or at risk of developing Alzheimer’s disease.
