Alzheimer’s Disease: Can It Be Detected With An Eye Exam?

Recent news stories have highlighted some exciting news from ophthalmology studies looking to see if Alzheimer’s disease can be diagnosed using information obtained from a non-invasive eye test performed as part of an eye exam.

The studies have evaluated the retina and optic nerve tissues in the back of the eye. These tissues are readily imaged by equipment found in an eye doctor’s office. The light signals detected by the retina are transmitted to the brain by the optic nerve, which is technically an extension of brain tissue. Researchers evaluated the correlation between the thickness of retinal tissue and also the density of blood vessels in the tissue using optical coherence tomography (OCT) scans and the presence of Alzheimer’s disease. The study found a less dense network of retinal blood vessels in individuals already diagnosed with Alzheimer’s disease.

This is exciting news. The thought is that these microvascular changes noted in the back of the eye may be a surrogate for similar blood vessel changes happening in the brain during the development of Alzheimer’s disease. Furthermore, if these types of changes could allow earlier diagnosis of Alzheimer’s, they could help doctors identify patients best suited for new therapies aimed at slowing or preventing the development of Alzheimer’s.

Of course, it will be years before these findings are validated and the appropriate imaging devices and algorithms are rolled out for use in the general public. For instance, while Dr. Potthoff has an OCT machine in his Traverse City MI office, it would need a database and appropriate algorithms to segment the right parts of the OCT eye scan and compare the measurements to normative databases of both people with and without Alzheimer’s disease to provide useful clinical information. With that said, it’s only a matter of time before we are able to diagnose more and more neurological diseases by imaging and examining a patient’s eyes.