Did you know that 94 percent of people with posterior cortical atrophy (PCA) problems develop Alzheimer’s disease? While the condition is rare, the link between ocular changes and cognitive decline isn’t. Previous studies have examined the impact of retinal vascular health on brain function—which supports theories that the eyes are a gateway to better understanding the brain. And now, scientists say a routine eye exam could detect signs of early Alzheimer’s before the onset of typical symptoms.
RELATED: Combining These 2 Supplements Can Slow Down Alzheimer’s Disease, Researchers Find.
Your eye health can say a lot about your brain health.
Changes in the shape and size of your retinal blood vessels can indicate the presence of early Alzheimer’s, according to a new study published in the journal Alzheimer’s & Dementia. That’s because the retina is an extension of the central nervous system—meaning, it shares “essentially the same tissue” as the brain.
“Your retina is essentially your brain, but it’s much more accessible because your pupil is just a hole, and we can see tons of stuff,” co-lead study author Alaina Reagan, PhD, a neuroscientist at The Jackson Laboratory (JAX), explained in a press release. “All the cells are very similar, all the neurons are quite similar, all the immune cells are quite similar, and they behave similarly under pressure if you’ve got a disease.”
All of this to say, your annual eye exam could also, potentially, serve as a brain health checkup.
“If you’re at an optometrist or ophthalmologist appointment, and they can see odd vascular changes in your retina, that could potentially represent something that is also happening in your brain, which could be very informative for early diagnostics,” noted Reagan.
RELATED: Doctors Warn This Common Medication May Be Linked to Dementia Risk.
Retinal vessels that look narrow or swollen could be an early sign of Alzheimer’s.
For the study, researchers looked at mice with the common genetic mutation “MTHFR677C>TTK,” which is a known Alzheimer’s risk variant. (The study also states that MTHFR677C>TTK occurs in up to 40 percent of humans.)
They conducted a traditional eye exam and found abnormalities in the blood vessels and arteries of the mice. More specifically, the retinas appeared to have “twisted vessels, narrowed and swollen arteries, and less vessel branching.” These changes were detected in young mice starting at six months old.
Twisted vessels “can result in turbulent blood flow, which promotes changes in blood pressure, degradation of elastin, and luminal shear stress,” wrote the authors. Additionally, it could be an underlying symptom of “poor blood flow and increased risk of cognitive decline.”
“We can see these wavy vessels in the retinas, which can occur in people with dementia,” Reagan said. “That speaks to a more systemic problem, not just a brain- or retina-specific problem. It could be a blood pressure problem affecting everything.”
What’s more is that female mice displayed worse eye health than their male peers. At one year old, they had “reduced vessel density and branching,” which the authors labeled as “progressive.” This corroborates a statistic from the Alzheimer’s Society that women have an increased risk of developing Alzheimer’s in their lifetime, compared to men.
According to Reagan, the study’s findings suggest “these systems in brain and retinal tissue are working in tandem.”
RELATED: Doctors Say This 1 Superfood Can Lower Your Dementia and Alzheimer’s Risk.
The takeaway:
Scientists say unusual changes in retinal blood vessels could serve as an early warning sign for neurodegenerative diseases, such as Alzheimer’s.
“Most people over 50 have some kind of vision impairment and get checked annually for prescription changes,” said Reagan. “Are they more at risk if they have these vascular changes, and is that a point when doctors could start mitigating brain changes? That could be 20 years before cognitive damage becomes noticeable to patients and their families.”
Going forward, the research team is partnering with dementia care experts from Maine’s Northern Light Acadia Hospital to study the correlation between mutation MTHFR677C>TTK and vascular changes in humans.
Source link
