An eye exam may help diagnosis Alzheimer's disease earlier

By Claire Wolters | Fact-checked by Jessica Wrubel
Published March 30, 2023

Key Takeaways

  • A new study suggests a pathway for early Alzheimer’s disease (AD) diagnoses—and it’s through the eyes.

  • If followed up by more studies, the findings could be a breakthrough in AD diagnosis and treatment.

  • Currently, no one test can diagnose AD and the condition has no cure.

A new study on Alzheimer’s disease (AD) reveals AD pathologies in the neurosensory retina—which the researchers say could serve as early biomarkers of the disease.[]

“Our findings provide novel and deeper understanding of the susceptibility of the retina to AD processes, including molecular, cellular, and structural abnormalities that can be detected in the earliest stages of functional impairment,” the researchers write. “Furthermore, our study has identified the pathological connections between the retina, brain, and cognition, proposing that the retina could serve as a reliable biomarker for non-invasive AD detection and monitoring.”[]

Currently, no one test can diagnose AD, so practitioners diagnose patients based on robust clinical analysis. This can include evaluation of the patient’s family, social, medical, and behavioral history, and other tests like medical and neuropsychological exams, labwork, and brain MRIs, to consider which factors contribute to dementia. The findings suggest that studying the eyes could be a way to indirectly study the brain, and diagnose AD.

“The eyes are not just the ‘windows of the soul,’ but also windows of the brain,” says Howard R. Krauss, MD, surgical neuro-ophthalmologist and director of Pacific Neuroscience Institute’s Eye, Ear & Skull Base Center at Providence Saint John’s Health Center in Santa Monica, CA. “This study confirms that the same cellular, chemical and molecular changes which are in evidence in the Alzheimer's brain are evident in the retina.”

While inspiring, the study results are “not directly applicable without surgically obtaining retinal tissue, which would be an impractical suggestion in pursuit of a diagnosis,” but encourage the development of future non-invasive tests to analyze the retina in vivo, Krauss adds.

“Consider that modern-day space probes and astronomic equipment can discern the chemical nature of gasses and substances light years away,” he adds, “we should certainly be able to scan the eye to identify the chemical markers within the retina allowing a diagnosis of Alzheimer's.”

A future Alzheimer’s cure could be possible too, he adds. But much more research, time, and monetary investments are needed before either becomes a reality.

“Once we have a retinal scan to directly visualize cellular, chemical, and molecular changes in association with Alzheimer's disease, that same technology may be employed to monitor rates of decline, or, hopefully, rates of recovery, by objective measurements made in [a] non-invasive fashion,” Krauss says.

While we wait for that to happen, Krauss encourages people to take lifestyle steps to reduce their risks of developing AD—and encourages physicians to talk to their patients about how they can individually mitigate risks early.

“All too often people and their families wait for symptoms and impairments before seeking attention and treatment,” Krauss says. “The most effective tools today in slowing the progress of Alzheimer's disease are the same key factors in achieving and maintaining wellness.”

Among other tips, he suggests encouraging patients to take care of their health even before they become sick, eliminate or cut back on smoking, alcohol, and drug use, follow a nutritious diet and incorporate exercise and physical activity into their lifestyle, prioritize sleep and stress reduction, and stay up-to-date with doctor’s appointments and vaccinations.

What this means for you

A new study shows that Alzheimer's Disease (AD) pathogens can be detected in the retina. In the future, diagnostic testing of the eyes could help detect AD early. However, more research—including how to create a non-invasive retina test—is needed before this can happen.

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