Studying the eye to improve Alzheimer’s diagnosis

‘The potential to use the eye as a window to the brain is an exciting concept,’ says Imre Lengyal, a Society-funded researcher at Queen’s University Belfast. 

He’s part of a team that hopes to find a way to monitor Alzheimer’s in its earliest stages by looking into your eyes – all inspired by an intriguing connection with Down’s syndrome. 

‘Dementia is a hugely important issue for society, and there is a major need for early identification of those at risk of Alzheimer’s disease,’ says Julie-Anne Little, Professor in Optometry and Vision Science at Ulster University. 

It’s known that people with Down’s syndrome have a higher risk of developing dementia.

Imre and Julie-Anne’s team have made links between how Down’s syndrome affects the eye and changes seen in the early stages of Alzheimer’s.

Clues to a link 

The team previously looked at how Down’s syndrome affects a person’s eyes.

They looked at the lens at the front of the eye, the retina, which senses light inside the back of the eye, and the choroid – a layer behind the retina with lots of blood vessels. 

‘We found evidence of early and unusual cataract formation, and thickening of both the retina and the choroid, compared to people without Down’s syndrome,’ says Imre. 

‘The findings suggested that inflammatory and accelerated ageing processes could be at play in Down’s syndrome,’ says Julie-Anne.

These inflammatory events may be connected with early events in Alzheimer’s disease.

Comparing changes 

In the coming two years, the team will compare changes in the eye caused by Down’s syndrome with what happens in older people –those who have mild cognitive impairment and those who don’t. 

As well as looking at people’s eyes and doing cognitive tests, they’ll collect blood, saliva and tear samples.

In these, they’ll look for ‘biomarkers’ – chemicals that are known to show up when someone has inflammation or Alzheimer’s. 

‘We’ll then study the link between changes in eye structures and fluid biomarkers,’ says Imre, ‘to help develop a better understanding of how Alzheimer’s disease develops. 

We believe these new insights will lead to more accessible, non-invasive ways to monitor Alzheimer’s disease from the earliest possible stage.

They hope that greater understanding will mean we can help people retain their eyesight for longer too. 

‘Preserving or improving vision is critical for all of us,’ says Julie-Anne, ‘but it is essential for those whose daily life is already affected by dementia.’