A new report shows that researchers can detect detect signs of Alzheimer’s disease in the tiny blood vessels at the back of the eye using ultrasensitive scanning. Duke University researchers found that these blood vessels were altered in patients with Alzheimer’s, but not in those with mild cognitive impairment (MCI) or with no signs of mental decline.
Dr. Dilraj Grewal, an associate professor of ophthalmology at the Duke Eye Center, said that “there was a significant reduction in the blood vessels’ density in the superficial layer of the retina” among the subjects with Alzheimer’s compared to those with MCI. He also added finding “a reduction in the thickness of (a specific layer of the retina) in the Alzheimer’s patients.”
Grewal explains that the retina is an extension of the brain, thus any changes in the brain are mirrored. If the brain suffers a neurodegenerative disease (such as Alzheimer’s), changed will also be found in the retina. The study was even able to find that the individuals with more severe Alzheimer’s had more severe loss of retinal blood vessels.
The doctor attributes the discovery to their new scanning technology, an optical coherence tomography angiography (OCTA). “With previous technology you were able to measure only the larger blood vessels in the back of the eye. Now we can look at blood vessels that are at the level of capillaries in the different layers of the retina. Therefore we are able to detect much smaller levels of change,” said Grewal.
Dr. Richard Isaacson, director of the Alzheimer’s Prevention Clinic in New York, calls the new research a “small step forward” but more focus is necessary for Alzheimer’s in its early stages. “We already have more definitive ways to diagnose dementia due to Alzheimer’s, but we need to see if OTCA can be a useful cost-effective screening test for pre-symptomatic Alzheimer’s,” said Isaacson.
Story from Reuters