You may already know that the size of your temporalis muscle, which helps to open and close your jaw, has been linked to dementia risk.
That’s because a smaller temporalis is often a sign of muscle loss (sarcopenia), which seems to be linked to the condition.
Additionally, sight loss has long been associated with an increased likelihood of developing dementia.
And now, researchers from New Zealand think that the blood vessel health and even thickness of your retina (a layer of tissue at the back of your eye which helps you to process light) could reveal your dementia risk in midlife, too.
What does retina blood vessel health have to do with dementia risk?
Three years ago, the University of Otago researchers published a study which looked at the thickness of participants’ retinal nerve fibre layer (RNFL) and ganglion cell layers (GCL).
They tested people in midlife (most of whom were 45) and found a link between thinning in a middle-aged person’s retina and decreased cognitive ability in earlier and later life.
They suggested that this could mean “RNFL may be a useful biomarker of early cognitive decline,” which is often seen as a precursor to dementia, “but further longitudinal studies are needed.”
Those “further studies” have since been carried out by some members of the same team.
By looking back at the database for the 2022 study (the Dunedin Multidisciplinary Health and Development Study, which recorded 45 years of health data from New Zealanders born in 1972-1973), the researchers formed a new study.
This time, they combined photos and scans of participants’ retinas with tests designed to predict a person’s risk of dementia.
They found that while the thickness of your retina may be weakly associated with dementia risk, the microvascular (tiny blood vessel) health of the tissue had a far stronger effect on dementia risk.
“Measures of retinal health, particularly microvascular measures, successfully capture ADRD [Alzheimer’s disease and related dementias] risk across several domains of known risk factors, even at the young midlife age of 45 years,” they wrote.
They add, “Retinal microvascular imaging may be an accessible, scalable, and relatively low-cost method of assessing ADRD risk among middle-aged adults.”
Does that mean we’ll have retinal dementia tests soon?
No. This study hasn’t given us enough evidence to implement anything yet, and it’s only been suggested as a risk factor, not a diagnostic tool.
Still, co-lead author of the study, Dr Ashleigh Barrett-Young, says: “It’s thought that many of the disease processes in Alzheimer’s are reflected in the retina, making it a good target as a biomarker to identify people at risk of developing dementia.”
She added, “I was surprised that venules (small blood vessels) were associated with so many different domains of Alzheimer’s disease – that suggests that it might be a particularly useful target for assessing dementia risk.”
So, while Dr Barratt-Youndg stressed “This research is still in an early stage, and we can’t predict your future looking at an eye scan,” she continued: ”“Hopefully, one day we’ll be able to use AI methods on eye scans to give you an indication of your brain health, but we’re not there yet.”
#Part #Eye #Reveal #Early #Dementia #Risk
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