Breakthroughs Beckon for Alzheimer’s

New eye tests in doctors' offices can now share critical information about the brain

by Jennifer Fallon | Updated 01 Sep 2016 at 5:41 PM

Every four seconds, a new patient is diagnosed with Alzheimer’s disease. The current number of patients is a stunning 35 million people worldwide — but epidemiologists predict that number will be closer to 115 million people by 2050.

In 2016, the United States will spend $236 billion on issues related to Alzheimer’s and other types of dementia. Yet we’re not even consistently diagnosing it yet.

Early intervention has the potential to drive down costs by as much as $2.6 billion in the U.S.

Right now, the only way to diagnose Alzheimer’s is through a test called positron emission tomography (PET scan), which creates images of amyloid plaques that build up in the brain years before symptoms appear. These scans can cost more than $7,000 and require expensive technology and equipment not widely available. They’re not covered by most insurance policies — so it’s unlikely many patients will be able to receive regular PET scans for early Alzheimer’s detection.

The only other option is a spinal tap, or lumbar puncture, which draws out some cerebrospinal fluid to test for abnormal proteins. But even that isn’t entirely reliable. And by the time a patient is tested for Alzheimer’s, he or she has likely already shown worrisome signs of memory loss and dementia.

So imagine the possibility of a simple smell test and retinal scan that can identify the disease early on. It’s a big step to be sure — and now research presented this week at the Alzheimer’s Association conference in Toronto shows it could soon be a reality.

“The smell system and the memory system are physically connected,” explained Dr. Suzanne Craft, a member of the Medical and Scientific Advisory Council of the Alzheimer’s Association, in a statement. It is likely an evolutionary advantage, she said: “It’s very important for you to be able to find food and remember where you found it.”

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A new study from Columbia University used a 40-point smell identification test to predict cognitive decline among a large sample of seniors. Identifying odors is different from detecting them. Identification requires patients to verbally or visually represent the odor and tap into their memories. Using this test, doctors accurately predicted the cognitive decline of 12.6 percent of the 397 people who participated.

“Many tests conducted in an eye doctor’s office can share clues about the brain,” said an Alzheimer’s expert.

The test isn’t a perfect indicator: It excludes individuals who already have altered olfactory senses due to either smoking or a longtime career in industrial labor. But it could hold promise for countless others.

Two other studies focused on the use of retinal scans. “Many diseases show up in the eye first,” Dr. Craft explained, among them multiple sclerosis and diabetes. “There are many tests conducted in an eye doctor’s office that can give us important clues about the brain.”

One study from the University of Waterloo showed that retinal imaging of Alzheimer’s patients could allow doctors to identify amyloid deposits — the same type of buildup identified in a PET scan.

“Retinal thinning and this type of imaging is a technology that’s already used in an ophthalmologist’s office to diagnose glaucoma. It may be there’s a whole arsenal of technology already available to the health care community to help diagnose Alzheimer’s,” said Dr. Heather Snyder, senior director of Medical and Scientific Operations at the Alzheimer’s Association.

There need to be more studies that show a broader association across a larger group of people, Dr. Synder told LifeZette — adding that retinal scans could be “developed as part of larger toolkit” for early detection.

Why is early detection so important? Dr. Robert Egge, chief public policy officer at Alzheimer's Association, said early intervention has the potential to drive down health care costs by as much as $2.6 billion in the U.S., mostly by preventing unneeded hospitalizations. Even if there isn't a cure yet, "first-generation treatments can drive down mortality, drive down the burden of the disease, and reduce the cost to the health care system," he said.

But mostly these early interventions aim at improving the lives of patients and families. Valerie King, a caregiver at Meadowbrook Manor in Los Angeles, said it's hard to watch Alzheimer's patients lose pieces of themselves bit by bit. "I take care of a man who used to be a Marine. He was very capable of taking care of himself, and now he has to let everyone else take care of him. It's hard to lose that dignity," she said.

Related: Boost Your Brain, Add Years to Your Life

King said she tries hard to let the patients she cares for — 40 in all — keep portions of that independence. Sometimes it's as small a gesture as encouraging them to tie their own shoes or brush their teeth. King approaches her job with more empathy than usual because she remembers as a girl helping to care for her great-grandmother, who also had Alzheimer's. Now she helps care for her grandmother, who suffers as her own mother did.

"These people don't actually die from Alzheimer's. They die from dehydration or starvation," King said. Sometimes they can't remember the meal they finished just 15 minutes ago. In addition to daily details, patients lose their existence to this debilitating disease. They don't just forget names — they lose a lifetime of memories.

The smell test and retinal scans may not be a cure for Alzheimer's — but they're a step in the right direction toward saving the lives and memories of people most at risk.

  1. Alzheimer's
  2. Alzheimer's Association
  3. Alzheimer's disease
  4. diagnostic tests
  5. Dr. Heather Snyder
  6. Dr. Suzanne Craft
  7. PET scans
  8. University of Waterloo
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