Study finds eye test could predict Alzheimer's before symptoms show

Vision issues like difficulty reading, driving, or judging distances may signal early Alzheimer's disease, the most common form of dementia. Studies suggest that changes in the eyes, such as blood vessel damage and beta-amyloid plaques, may indicate Alzheimer's progression. Retinal scans and detecting plaques in the eye could offer noninvasive ways to diagnose the condition.

The researchers analyzed data from over 8,000 healthy adults who underwent visual sensitivity testing. This test evaluated participants' visual processing speed and reaction time by prompting them to press the space bar when they observed a triangle forming among moving dots on a computer screen.

“We explored visual sensitivity as a potential predictor of dementia due to evidence suggesting that individuals with dementia often face visual processing difficulties, even in the early stages of the disease. Visual impairments have been associated with a higher risk of developing dementia in the future, indicating that assessing visual processing abilities could be beneficial for dementia risk evaluation,” said Ahmet Begde, a doctoral researcher in the School of Sport, Exercise, and Health Sciences at Loughborough University in the U.K

The results revealed that participants with lower scores on the visual sensitivity test had a higher risk of a future dementia diagnosis. Researchers noted that out of 8,623 healthy people about 6% (587) patients could develop dementia later in their life.

“We found that a low score on this test missing many targets can indicate future dementia risk, on average 12 years before the diagnosis, especially when using this test with other specific memory tests and some tests of global cognitive functioning worked well to predict this risk,” said Prof. Hogervorst, lead author of this study.

Reference: Begde, A., Wilcockson, T., Brayne, C. et al. Visual processing speed and its association with future dementia development in a population-based prospective cohort: EPIC-Norfolk. Sci Rep 14, 5016 (2024). https://doi.org/10.1038/s41598-024-55637-x