Your eyes might be more than the windows to your soul. They might be the windows to your brain health too.
Eye exams can already uncover or confirm certain cancers, diabetes, and high blood pressure. Now experts say the eyes might hold the answer to diagnosing Alzheimer’s disease.
Alzheimer’s is difficult to diagnose. For decades, an autopsy was the only surefire way to confirm it. No one knows why it starts, but in the first stage, benign amyloid proteins divide improperly, producing toxic, sticky beta-amyloid fragments, which clump together to form plaques.
Years later, twisted, microscopic tangles of the protein tau join beta-amyloid plaques to prevent brain cells, especially those responsible for memory, learning and communication, from transmitting information. Inflammation, triggered by the body’s immune system, leads to the shrinking and death of brain cells.
Keith L. Black, MD, chairman of the Cedars-Sinai Medical Center Department of Neurosurgery in Los Angeles, says as much as 50 percent of brain cells are already lost by the time an Alzheimer patient shows noticeable cognitive decline. Treatments fail not because they don’t work, but because they start too late. To get ahead of the disease, doctors needed to find a way to diagnose it sooner.
Scientists found other methods — positron emission tomography of the brain and measuring concentrations of Alzheimer’s biomarkers in the cerebrospinal fluid — but these tests were invasive and expensive. To even have a shot a therapeutic intervention, doctors need an accurate, inexpensive and practical method of screening people.
Now they may have found one.
Black and his Cedars-Sinai team discovered that beta-amyloid plaques showed up in the retinas of Alzheimer’s cadavers but not in the retinas of non- Alzheimer’s cadavers, and they proved there was a correlation between the number of beta-amyloid plaques in brain and the number in the retina.
The team, led by Maya Koronyo, a research scientist at the Maxine Dunitz Neurosurgical Institute and associate professor of neurosurgery and biomedical sciences at Cedars-Sinai, working with a team from NeuroVision Imaging, developed a non-invasive retinal scanner that could detect beta-amyloid plaques in the retina. They gave patients curcumin, the bright yellow chemical in turmeric, because it binds well with beta-amyloid plaques, and it can cross the retinal barrier. Plus, it’s a natural fluorochrome that generates a florescent signal: It makes the plaques light up.
The study found that beta-amyloid plaques did show up in the retinas of live test subjects and in amounts that correlated with the plaques found in their brains using PET scans. “The presence of amyloid plaques is the most important risk factor of Alzheimer’s,” Koronyo said. The presence of beta-amyloid plaques in a retinal scan is strong evidence to predict a diagnosis of Alzheimer’s Disease years before a person shows cognitive decline.
How many years? Researchers are also investigating that now, but Koronyo said, “So far, we have found the amyloid pathology in the retina of all early-stage cases. [Plaques] can appear 20 to 25 years prior to cognitive decline in the brain.”
An early diagnosis gets treatment started sooner, when it will do more good. “There is a lot to offer in terms of prevention, especially in the field of lifestyle and immune system function,” Koronyo said. “The earlier the detection the better the ability to modify the course of the disease. This is what most scientists believe.”
The Alzheimer’s Association agrees early treatment works better. Studies show making lifestyle changes like following a diet plan similar to the Mediterranean diet, moderate physical exercise, and challenging the brain with puzzles and other activities does help slow the progression of the disease.
Koronyo is working on an immune-system-based therapy that would harness the immune system’s ability to repair and regenerate the central nervous system and regulate the detrimental inflammation of Alzheimer’s.
Retinal exams have tremendous value to the research community, who now have an accurate and relatively simple tool to measure the progression of Alzheimer’s and to assess the effectiveness of treatment plans.
Today, more than 5 million people are living with Alzheimer’s, and 2017 is the first year that caring for dementia patients will cost more than $250 billion. And that doesn’t count the unpaid care provided by more than 15 million Americans. In the future, those numbers will only grow.
But there is good news. Black and other experts agree: In order to make an impact, Alzheimer’s need not be cured – just slowed down.
ALZHEIMER’S WARNING SIGNS
- Memory loss that disrupts daily life.
- Challenges in planning or solving problems
- Difficulty completing familiar tasks at home, at work or at leisure
- Confusion with time or place
- Trouble understanding visual images and spatial relationships
- New problems with words in speaking or writing
- Misplacing things and losing the ability to retrace steps
- Decreased or poor judgment
- Withdrawal from work or social activities
- Changes in mood and personality
Want to help put an end to this terrible disease? Join one of these local Walks To End Alzheimer’s:
West Palm Beach — Oct. 28, 9 a.m., CityPlace
Boca Raton — Nov. 12, 8:30 a.m., Mizner Park