Research shows that in the patients with Alzheimer’s disease (AD), the small blood vessels in the retina at the back of the eye are altered. Patients with no symptoms of AD, but with family history of the same, have shown these telltale signs. People with AD and those with only mild cognitive impairment can also be distinguished with this method, according to the researchers at Duke University, United States.
This kind of precise and non-invasive imaging is called optical coherence tomography angiography (OCTA). It enables physicians to see the smallest veins in the back of the eye, including the red blood cells moving through the retina.
As the retina is connected to the brain through the optic nerve, the deterioration in the retina and its blood vessels may mirror the changes going on in the blood vessels and structures in the brain, thereby offering a window into the disease’s process.
Researchers found that the people with AD had a loss of small retinal blood vessels at the back of the eye and that a specific layer of the retina was thinner. Neither the people with mild cognitive impairment, nor any healthy individuals show these changes.