On 2 April, researchers from the United States of America published a study on the question whether the in previous studies observed decreased blood flow in the eyes of people with Alzheimer’s disease (AD) is also present in people with early AD and people with amnestic Mild Cognitive Impairment (aMCI) - a form in which memory problems are dominant. The research was issued in the journal PLOS ONE. For their study the team involved 32 participants out of which 16 were either affected by aMCI or early AD and 16 people without cognitive or memory related problems.
In addition to the measurement of blood flow, the scientists also performed tests on blood vessel density, as well as the thickness of the nerve fiber layer (back of the eye), amongst others. The scan results were then comparing between the two groups. In addition, the researchers also checked whether the measures taken from the eyes correlated with cognitive performance (assessed with a pen and paper test).
Their results showed that the two groups differed in two measures, the parafoveal superficial capillary plexus as well as in an index on blood flow. In addition to this, the researchers also reported that they found a correlation between the pen and paper test performance and the vessel density (in the parafoveal superficial capillary plexus) as well as the density of vascular layers (capillary vessel length density of the radial peripapillary capillary). These findings led them to the conclusion that the imaging technique they used – entitled optical coherence tomography angiography (OCTA) – might be helpful to identify individuals with early cognitive impairment in future, rendering this technique an interesting area for further research.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214685