A routine trip to the eye doctor may one day do more than check your vision—it could also provide an early warning of Alzheimer’s disease.
New research suggests that changes in the tiny blood vessels in the retina may signal problems in the brain long before memory loss or confusion appear.
The study, published in Alzheimer’s & Dementia, comes from The Jackson Laboratory (JAX), where researchers are investigating how the eye can act as a window into brain health.
Their latest findings in mice show that a common genetic mutation tied to higher Alzheimer’s risk also causes abnormal changes in the eye’s blood vessels, pointing to the retina as a powerful biomarker for dementia.
Alaina Reagan, a neuroscientist at JAX who led the study with Professor Gareth Howell, explains the idea simply: “If your optometrist sees unusual blood vessel patterns in your retina, that may be reflecting changes in your brain.
Because the retina is essentially part of the central nervous system, it can give us early clues about diseases like Alzheimer’s.”
The retina shares many features with brain tissue, including similar types of neurons and immune cells. Unlike the brain, however, it is easily accessible because eye specialists can look directly at it using simple imaging tools.
That accessibility makes it a promising candidate for noninvasive, affordable screening.
In the study, scientists focused on mice carrying the MTHFR677C>T mutation, which is found in up to 40% of people worldwide and is associated with a higher risk of Alzheimer’s.
By just six months of age, these mice showed noticeable changes in the retina: twisted vessels, narrowed arteries, swollen sections, and fewer branches. Such changes suggest reduced blood flow and oxygen supply—problems also seen in the brains of people with dementia.
The findings echo a 2022 study by the same team, which showed that mice with this mutation also had fewer blood vessels in their brains and poorer circulation. Together, the results highlight the strong link between vascular health in the eye and in the brain.
The researchers also looked at molecular changes.
They found disruptions in energy production, in the removal of damaged proteins, and in the structure of blood vessel support systems. These overlapping changes in both the brain and retina suggest that the two organs are affected in similar ways by the mutation.
Sex and age appeared to play important roles as well. Female mice developed worse vascular problems as they aged, with fewer and less healthy vessels by 12 months. This finding mirrors the fact that women are more likely than men to develop Alzheimer’s, according to the World Health Organization.
The next step is to see whether these eye changes occur in humans. The JAX team is working with clinicians at Northern Light Acadia Hospital in Maine to test whether retinal scans can reveal early dementia risk in patients. If so, eye exams could become an important tool in spotting Alzheimer’s years—possibly even decades—before symptoms begin.
Since most adults over 50 already see eye specialists for routine checks, these exams could double as screenings for brain health. Spotting vascular changes early could give doctors time to recommend further tests or preventive measures, potentially slowing or even preventing cognitive decline.
As Reagan puts it, “This could give us a 20-year head start in fighting Alzheimer’s.”
Source: KSR.
