Evidence mounts that an eye scan may detect early Alzheimer's disease

October 29, 2018, American Academy of Ophthalmology

Results from two studies show that a new, non-invasive imaging device can see signs of Alzheimer's disease in a matter of seconds. The researchers show that the small blood vessels in the retina at the back of the eye are altered in patients with Alzheimer's. Even patients who have a family history of Alzheimer's but have no symptoms show these telltale signs. And they showed that they can distinguish between people with Alzheimer's and those with only mild cognitive impairment. Results from these studies are being presented at AAO 2018, the 122nd Annual Meeting of the American Academy of Ophthalmology.

A new kind of precise and non-invasive imaging called optical coherence tomography angiography (OCTA) has assisted much of the recent research on the eye's connection with Alzheimer's. It enables physicians to see the smallest veins in the back of the eye, including the red blood cells moving through the retina.

Because the retina is connected to the by way of the optic nerve, researchers believe that the deterioration in the retina and its blood vessels may mirror the changes going on in the blood vessels and structures in the brain, thereby offering a window into the disease process.

Diagnosing Alzheimer's is a currently a challenge. Some techniques can detect signs of the disease but are impractical for screening millions of people: Brain scans are expensive and spinal taps can be harmful. Instead, the disease is often diagnosed through memory tests or observing behavior changes. By the time these changes are noticed, the disease is advanced. Even though there is no cure, early diagnosis is critical as future treatments are likely to be most effective when given early. Early diagnosis would also give patients and their families time to plan for the future.

The goal of this latest research is to find a quick, inexpensive way to detect Alzheimer's at the earliest signs.

Researchers at Duke University used OCTA to compare the retinas of Alzheimer's patients with those of people with , as well as healthy people. They found that the Alzheimer's group had loss of small retinal at the back of the eye and that a specific layer of the retina was thinner. Even people with mild cognitive impairment did not show these changes.

Ophthalmologist and lead author Sharon Fekrat, M.D., professor of Ophthalmology at Duke, along with colleague Dilraj Grewal M.D., associate professor of Ophthalmology at Duke, and their research team expect that their work will have a positive impact on patient's lives.

"This project meets a huge unmet need," Dr. Fekrat said. "It's not possible for current techniques like a brain scan or lumbar puncture (spinal tap) to screen the number of patients with this disease. Almost everyone has a family member or extended family affected by Alzheimer's. We need to detect the disease earlier and introduce treatments earlier."

Because genes play a significant role in how Alzheimer's disease begins and progresses, another team of researchers from Sheba Medical Center in Israel examined 400 people who had a of the disease but showed no symptoms themselves. They compared their retina and with those who have no family history of Alzheimer's.

They found that the inner layer of the retina is thinner in people with a history. The brain scan showed that their hippocampus, an area of the brain that's first affected by the disease, had already begun to shrink. Both factors, a thinner inner layer and smaller hippocampus, were associated with scoring worse on a cognitive function test.

"A brain scan can detect Alzheimer's when the is well beyond a treatable phase," said lead researcher Ygal Rotenstreich M.D., an ophthalmologist at the Goldschleger Eye Institute at Sheba Medical Center. "We need treatment intervention sooner. These patients are at such high-risk."

Explore further: Alzheimer's one day may be predicted during eye exam

Related Stories

Alzheimer's one day may be predicted during eye exam

August 23, 2018
It may be possible in the future to screen patients for Alzheimer's disease using an eye exam.

New appropriate use criteria for lumbar puncture in Alzheimer's diagnosis

October 10, 2018
In preparation for more tools that detect and measure the biology associated with Alzheimer's and other dementias earlier and with more accuracy, an Alzheimer's Association-led Workgroup has published appropriate use criteria ...

Alzheimer's detected before symptoms via new eye technology

July 11, 2016
Rockville, Md. Scientists may have overcome a major roadblock in the development of Alzheimer's therapies by creating a new technology to observe—in the back of the eye—progression of the disease before the onset of symptoms. ...

New way of defining Alzheimer's aims to find disease sooner

April 10, 2018
Government and other scientists are proposing a new way to define Alzheimer's disease—basing it on biological signs, such as brain changes, rather than memory loss and other symptoms of dementia that are used today.

Noninvasive eye scan could detect key signs of Alzheimer's years before patients show symptoms

August 17, 2017
Cedars-Sinai neuroscience investigators have found that Alzheimer's disease affects the retina—the back of the eye—similarly to the way it affects the brain. The study also revealed that an investigational, noninvasive ...

Detecting diminished dopamine-firing cells inside brain could reveal earliest signs of Alzheimer's

March 27, 2018
A new link between diminished input from dopamine-firing cells deep inside the brain and the ability to form new memories could be crucial in detecting the earliest signs of Alzheimer's disease.

Recommended for you

New information on the pathological mechanisms of Alzheimer's disease

November 21, 2018
Researchers at the University of Helsinki have discovered a mechanism by which harmful tau protein aggregates are transmitted between neurons. Alongside amyloid plaques, tau aggregates in the brain are a significant factor ...

DNA vaccine reduces both toxic proteins linked to Alzheimer's

November 20, 2018
A DNA vaccine tested in mice reduces accumulation of both types of toxic proteins associated with Alzheimer's disease, according to research that scientists say may pave the way to a clinical trial.

For Down syndrome adults, death and dementia often come together

November 19, 2018
(HealthDay)—Seven in 10 people with Down syndrome show evidence of dementia when they die, new research from Britain reveals.

Scientists combine technologies to view the retina in unprecedented detail

November 14, 2018
By combining two imaging modalities—adaptive optics and angiography—investigators at the National Eye Institute (NEI) can see live neurons, epithelial cells, and blood vessels deep in the eye's light-sensing retina. Resolving ...

Meditation and music may alter blood markers of cellular aging and Alzheimer's disease

November 13, 2018
A research team led by Dr. Kim Innes, a professor in the West Virginia University School of Public Health, has found that a simple meditation or music listening program may alter certain biomarkers of cellular aging and Alzheimer's ...

Eyepatch with dissolvable needles used to treat eye disease

November 12, 2018
A team of researchers affiliated with several institutions in Singapore has developed an eyepatch with dissolvable needles for use in treating eye diseases. In their paper published in the journal Nature Communications, the ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

shortwave02001
not rated yet Oct 30, 2018
My mother had Alzheimers my eyes don't naturally focus at the same point but most of my life the brain made the corrections so I can see normally. I am 61 now and sometimes the brain is not making the corrections so I am seeing different things from each eye,

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.