How eye change can reveal dementia or diabetes before symptoms even appear

They may be the windows to the soul but it’s now been found eyes can provide crucial insight into the brain, which can potentially help detect diseases like dementia, multiple sclerosis and diabetes.

They may be the window to the soul, but researchers have found the eyes also give an insight into the brain that could help manage diseases such as dementia, multiple sclerosis and diabetes.

An international team led by the WEHI in Victoria say it is the retina, a complex layer of tissues that sits behind the lens of the eye, that holds the key.

Lead researcher Dr Vicki Jackson said the retina was made up of cells similar to those found in the brain that delivers information to it from the eye.

In a new study published on Tuesday night, the team linked retinal changes to a range of diseases.

Dr Jackson said as a result optical coherence tomography (OCT) imaging of the eye may potentially be used to help detect disease before patients had any symptoms.

They used AI to create one of the largest and most detailed maps of the retina produced.

These maps, Dr Jackson said, helped to identify new genetic factors that influence retinal changes such as thinning or increased thickness.

WEHI researcher Dr Vicki Jackson led the new international study. Picture: WEHI

She said the team was surprised by the genetic associations that were affecting different parts of the retina.

The statistician and gene expert says the maps could be used to pave the way for improved routine eye care imaging as a disease screening tool.

The team says the research also reinforces the growing field of oculomics, using the eye to diagnose health conditions, as a powerful and non-invasive approach for predicting and diagnosing diseases.

Dr Jackson said retinal imaging should be seen as a doorway into the central nervous system.

“We’ve shown that retinal imaging can act as a window to the brain by detecting associations with neurological disorders like MS and many other conditions,” said Dr Jackson said.

For this study, published in Nature Communications, the team used eye scans of more than 50,000 people from the UK Biobank study.

The new study shows changes in the retina are indicative of disease. Picture: iStock

The volunteers had OCT, a painless and quick imaging method that creates pictures of the back of the eye.

“If we’re learning more about the retina and how it links to the brain, we’re getting more insight, simply by looking at the eyes, about brain health and general health,” Dr Jackson said.

She said changes in the retina were indicative of disease. An example was that many people with MS developed optic neuritis, an inflammation of the optic nerve.

“It’s already known that this can lead to thinning of the retina,” she said. “Something that we found was when we linked retinal inflammation with information about disease, we did see that people who had an MS diagnosis had particular areas of the retina which were thinner compared to everyone else.

“We don’t know if, for example, the disease is causing changes in the retina or if there is some other underlying issue which is causing both the disease and changes in the retina.

“We have identified links, but understanding how different diseases may be impacting the retina requires more work.”

Next, she said was for the researchers to break it down further and look at each of the 10 individual layers of the retina.

“By looking at each different layer it should give us extra information and help us to interpret what is going on more,” she said.

“The end result potentially will be identifying disease before symptoms present. That will be life-changing for many people.”

Originally published as How eye change can reveal dementia or diabetes before symptoms even appear