High street opticians could use AI to spot dementia risk with eye scan

The Guardian

09-03-2025

High street opticians could play a key role in pinpointing individuals at risk of dementia by spotting distinctive patterns in the retinas of those in the early stages of cognitive decline. These diagnoses would carried out during routine eye checks.
The prospect follows the development of an AI technique known as Quartz that can be used to study eye scans and identify key differences in the shapes and sizes of retinal blood vessels in a few seconds. The technology automatically measures width and the extent to which these tiny veins and arteries – known as arterioles and venules – twist and turn.
The blood vessels in the eye act as an extension of those in the brain and the development of Quartz gives researchers a unique opportunity to analyse retinal scans as a non-invasive way to assess the characteristics of blood vessels elsewhere. In particular, it allows them to study the eye for markers of brain health and for signs of neurodegeneration.
Scientists based at the newly formed research centre City St George's, University of London used Quartz to carry out eye scans of more than 63,000 people aged between 40 and 69. The team then assessed each person's cognitive score using a combination of tests of memory, reaction time and intelligence and compared results with images of their eye scans.
The researchers found that those possessing retinal blood vessels that had reduced width and had particular patterns of twisting were linked to lowered scores in tests for memory, reaction time and intelligence. These associations were adjusted for age, sex and ethnicity.
As to the reasons for this linkage, the scientists believe changes in retinal blood vessels may be due to reduced blood supply in the brain, which in turn may be an early cause or consequence of diseases such as dementia and Alzheimer's. The crucial point is that by studying the eye in this way it should become possible to pinpoint those in the early stages of neurodegenerative conditions.
This point was stressed by Professor Chris Owen, lead author of the study which was funded by Alzheimer's Research UK and published in the journal Alzheimer's & Dementia. He said the technique could one day be 'seamlessly embedded' into the daily routines of high street opticians and eye clinics. 'It would provide an easily accessible, low cost and quick way to flag people who are at risk of developing neurodegenerative conditions in the future without the need of invasive tests.'
His comments were backed by David Thomas, head of policy for Alzheimer's Research UK. He described the prospect of developing a way to detect early signs of dementia through routine eye tests at a high street optician as a gamechanger. 'Integrating these scans with existing tests, like brain scans, would ensure people get the full picture of their condition, and the support they deserve, more quickly,' he said.
At present, there are no treatments that can cure neurodegenerative conditions like Alzheimer's disease, and the development of a test that could pinpoint individuals in the early stages of untreatable condition raises concerns. However, Thomas stressed that only individuals who specifically request a retinal eye scan that would reveal their possible cognitive decline would be given such a test.
'It is also very unlikely that we will have this technique ready for high street use for another five years. By that time the first effective treatments for dementias may have become available.
'When these arrive, we will want to have ways to pinpoint those in the early stages of dementia, and eye scan tests could prove invaluable for doing this.'