I like to keep track of innovation in all sectors, including healthcare, where innovation tends to be harder to get to market. Innovation can come in so many forms: new kinds of insurance, medical devices, easy-to-access clinics, and updates to existing procedures. What I’m especially excited about is a new way to diagnose Alzheimer’s by looking at the retina . Unlike existing diagnostics, it would be quick, cheap and precise.
To back up for a moment, let’s look at the relationship between Alzheimer’s and dementia. Alzheimer’s disease (discovered by Dr. Alois Alzheimer in 1906), is the most common way people develop dementia. Which means that there are kinds of dementia which are not related to Alzheimer’s. A paper in American Geriatric Psychiatry found that in 1998, 6%-10% of adults 65 years old and older in North America had dementia, with Alzheimer’s disease accounting for two-thirds of these cases. By including milder forms of dementia, the percentages doubled, from 12%-20% for the same age group. That translates to 5.7 million Americans affected by Alzheimer’s .
Considering the prevalence, it’s surprising that the bevy of diagnostic tools to date have been fairly lackluster. What do we have to work with currently? Brain scans, which range from $787 to $1,767. Spinal taps, which can inflict permanent damage if done incorrectly. Cognitive testing, which can have mixed results. Usually a diagnosis comes from a combination of techniques. But what we need is a cost-effective, precise way to check millions of older Americans for signs of the disease. And that’s exactly what we get with this new tool.
On a personal note, I once had an Alzheimer’s scare with my mom, who is now 95 years old. A few years back, she was worried about her memory, although I never noticed anything amiss. Sure, there was the odd sentence left hanging, but nothing drastic. So she decided to see a gerontologist who was also a licensed psychiatrist, and they did a neuropsychological evaluation, asking her a bunch of questions (“Who is the president? What day is it?”). She got so nervous about the whole thing that she ended up answering incorrectly more than once, and it got the doctor thinking that she had significant memory loss, which simply wasn’t the case. Of course we got a second opinion, but clearly this is no way to make a diagnosis.
What researchers have found is that the small blood vessels behind the eye in people with Alzheimer’s are smaller and thinner, something that’s now noticeable with the use of optical coherence tomography angiography (OCTA), non-invasive imaging. With OCTA, doctors are even able to see the red blood cells moving through the retina. The retina is connected to the brain by the optic nerve, leading researchers to hypothesize that changes in the blood vessels behind the eye may parallel changes to happening in the brain itself, which is where Alzheimer’s does its damage.
While there is no cure for Alzheimer’s, screening millions of Americans with a quick and painless method would put a lot of minds at ease. The greater the number of people we can accurately diagnose translates to better understanding of the disease, and the better we understand it the more hope there is for treatment or even a cure. In the meantime, the more forewarning you get the better.
Yet how long will it be until this become widely available? It’s hard to tell. The barriers to innovation in health care are many, but I have to think that this kind of leap forward is something no one would want to ignore.
I corresponded with Sharon Fekrat, M.D., professor of Ophthalmology at Duke, and her colleague Dilraj Grewal M.D., associate professor of Ophthalmology at Duke, the lead authors of this study, presented at the 122nd Annual Meeting of the American Academy of Ophthalmology, to find out what to expect.
“For starters, with regard to non-invasive imaging, while OCT is in widespread use, OCTA is newer. Dr. Fekrat told me that “OCTA is available in some retinal specialists’ offices” globally, but there’s no known database showing which offices have it and which do not. “Duke, for example, will have an OCTA soon and the Durham VA Medical Center Eye Clinic just got one.”
Three companies currently sell OCTA with the proprietary analytic software required to do make these kinds of diagnoses, so the equipment is very much on the market. But that’s just one part of the puzzle.
Dr. Fekrat cautioned that this method of diagnosing Alzheimer’s “still requires validation and larger scale study,” and is very much dependent on funding. If the funding comes through, Dr. Fekrat estimates that OCTA could be in use in two years time, but that doesn’t mean that you could simply head to your ophthalmologist for an eye exam and get a diagnosis.
“The diagnosis of Alzheimer’s disease may remain multifactorial and multidisciplinary,” Dr. Fekrat explained. “The retina doctor may perform such testing as ordered by the neurologist who would then incorporate our findings and perhaps risk assessment (and even prognostic assessment) into their examination.”
Still, that sounds better than any options currently available. And it could get even better. What Dr. Fekrat and her colleague, Dilraj Grewal, are studying now is just how early Alzheimer’s can be detected.
“Currently, we are able to detect a significant difference between normal controls and Alzheimer’s patients,” Dr. Fekrat wrote. “We, in addition to others around the world, are studying either individuals with a family history of Alzheimer’s but no symptoms and/or individuals at high genetic risk (as determined with blood testing) but without symptoms to help answer this question.”
Wouldn’t that be something? While OCTA diagnosis may require FDA approval, the opportunity for application is remarkably large. It has been estimated that globally, there are 4.6 million new cases of dementia each year; by 2040 there will be 81.1 million people affected. And to think that we may one day be able to predict who will eventually show signs of Alzheimer’s could allow us to do more to support them through it — and keep family members from guessing. Peace of mind for all.