Scientists May Detect Alzheimer's Disease Early with New Eye Exams and Smell Tests

There may be a new way to predict the development of Alzheimer's disease. Researchers have found that a decreased ability to identify odors might herald its onset, and that an eye examination could also detect the buildup of beta-amyloid, which is a protein associated with the disease.

In a series of research trials reported at the Alzheimer's Association International Conference in Copenhagen, scientists examined different ways to detect the disease in patients. In one study, researchers found that the decreased ability to identify odors was associated with loss of brain cell function and a progression of Alzheimer's. In another, scientists found that the level of beta-amyloid detected in the eye was significantly corrected with the burden of beta-amyloid in the brain and allowed researchers to identify people with Alzheimer's.

"In the face of the growing worldwide Alzheimer's disease epidemic, there is a pressing need for simple, less invasive diagnostic tests that will identify the risk of Alzheimer's much earlier in the disease process," said Heather Snyder, Alzheimer's Association direct of Medical and Scientific Operations, in a news release. "This is especially true as Alzheimer's researchers move treatment and prevention trials earlier in the course of the disease. More research is needed in the very promising area of Alzheimer's biomarkers because early detection is essential for early intervention and prevention, when new treatments become available."

Discovering Alzheimer's early is crucial and these new markers could help with that. In the case of sense of smell as the disease begins to kill brain cells, it also kills cells associated with smell. This means that there could be a role for smell identification testing in clinically normal, older individuals at risk for Alzheimer's. In the case of vision, scientists can detect beta-amyloid plaques in the retinas of people with Alzheimer's, which could also potentially be used for early detection.

"We envision this technology potential as an initial screen that could complement what is currently being used: brain PET imaging, MRI imaging, and clinical tests," said Shaun Frost of the CSIRO, who conducted the vision study.

The findings could help researchers detect the disease earlier in individuals, which could also mean an earlier start to treatment and a better outcome.