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.

Koronyo Y, Rentsendorj A, Mirzaei N, et al. Retinal pathological features and proteome signatures of alzheimer’s disease. Acta Neuropathologica. 2023;145(4):409-438. doi:10.1007/s00401-023-02548-2

“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.”

Koronyo Y, Rentsendorj A, Mirzaei N, et al. Retinal pathological features and proteome signatures of alzheimer’s disease. Acta Neuropathologica. 2023;145(4):409-438. doi:10.1007/s00401-023-02548-2

“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.