A Simple Eye Test Could Detect Alzheimer’s Sooner Than Ever Before, Scientist Discovers

Besides the toll it can take on patients and their caregivers, one of the most difficult parts of Alzheimer’s disease can be reaching a diagnosis. Even those who take steps to reduce their risk of cognitive decline may not be able to notice it until it’s in its middle or late stages, according to Johns Hopkins Medicine. Fortunately, rigorous research is working to better our understanding of the condition and tackle it early on. And now, scientists say there’s a promising development thanks to a simple eye test that could help detect Alzheimer’s much sooner than ever before.

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An eye test could detect Alzheimer’s disease at least 2 years sooner.

Pinpointing the beginning stages of dementia has remained a dark spot in medical research. By the time many patients have begun showing some of the most severe symptoms of cognitive decline, it can be too late for doctors to take therapeutic action to slow its progression.

But in a study published in the Journal of Alzheimer’s Disease, scientists say they may have come across a significant advancement in detecting Alzheimer’s disease earlier on, PsyPost reports.

According to Jeffrey N. Weiss, the study’s lead author and founder of Micron Ophthalmic, PET scans have been the go-to diagnostic tool for Alzheimer’s disease, despite being relatively expensive, invasive, and uncomfortable for patients. They’re also only 70 percent accurate at early enough stages where effective treatment can begin.

“It was clear to me that something had to change,” Weiss told PsyPost. “In my work as a physician and electrical engineer, I had employed dynamic light scattering spectroscopy and knew that it could be useful in providing a rapid, cost-effective, noninvasive, and quantitative measurement. Most impressively, we’ve seen that the technology is capable of diagnosing Alzheimer’s disease at least two years earlier than any current method, opening the window for preventative care.”

Specifically, Weiss decided to look at something known as Brownian movement, which refers to how proteins move within the body. He hypothesized that using a technique known as dynamic light scattering spectroscopy (DLS), he could monitor a patient’s retina using a camera while they stared at a dim red light for five seconds. Specialized software can then analyze the protein movement in the retina, which can act as a proxy for brain health, thanks to the fact that it develops from the same tissue in the earliest phases of in utero development.

To conduct the experiment, Weiss gathered three different groups of participants, including 17 who were deemed healthy with no diagnosed eye issues, 15 who had shown signs of cognitive decline, and 17 who had been diagnosed with likely Alzheimer’s disease.

Using the healthy cohort as a control, he noted a specific pattern in four patients within the cognitive decline group that suggested slower protein movement. Within six to 12 months, these participants were officially diagnosed with Alzheimer’s disease.

Weiss also found that out of the 17 likely Alzheimer’s patients tested, 11 who had tested positive for amyloid buildup that typically confirms later stages of the disease showed an identical slower movement pattern. The other five patients in the group were accurately found to be negative by the light testing, as confirmed by later PET scans.

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Are the eye tests reliable for Alzheimer’s detection?

According to Weiss, dynamic light scattering can be an effective diagnostic tool for cognitive decline because it can be used to detect issues on a molecular level well before basic imaging can reveal physical changes. It also has some significant advantages over traditional testing methods, including being far cheaper, faster, and comfortable for patients.

“The retina is an outgrowth of the brain—it is important to acknowledge its growing relevance as an active observation site for biomarkers related to Alzheimer’s disease,” Weiss told PsyPost. “The test itself addresses many of the major issues in Alzheimer’s diagnostics: the complexity of testing in vulnerable populations, the cost-effectiveness of those tests, the elimination of ambiguity or subjectivity in the results, and most importantly, the stage at which we are able to identify the disease.”

More research is needed to prepare this technique for widespread use.

Weiss admitted that the small cohort sizes presented a significant limitation for the study, adding that further research using a more diverse group would be vital to expanding upon the findings. But he was confident that gathering more evidence could help make the results “irrefutable,” and that he hopes to expand access to the testing machines to more sites scanning for Alzheimer’s disease after receiving federal approval.

“We have a host of options from there, but one that looks particularly enticing in terms of creating a generational impact through this invention is to use it as an accompaniment for Alzheimer’s drug trials,” Weiss told PsyPost. “It can collect far more data, at far shorter intervals, for a far lower cost than any other technology currently employed for this purpose.”

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The takeaway:

In a recent study, researchers found that a technique known as dynamic light scattering spectroscopy could help doctors diagnose Alzheimer’s disease at least two years sooner than current testing abilities allow.

Using a camera to record protein movement in the retina while a patient looks at a dim red light for five seconds, the new technique is not only less invasive and more comfortable than the currently used PET scan, but also far more affordable.

Results of a study found that DLS accurately predicted an Alzheimer’s diagnosis in patients who had shown early signs of cognitive decline, while also correctly marking the same protein movement patterns in patients who had been diagnosed with likely Alzheimer’s.

The scientist in charge of the study says he hopes to further his research using a larger, more diverse participant pool and expand access to the testing machines when they receive approval.