Alzheimer's disease could be detected in the eyes

Many ongoing studies are investigating ways to screen for Alzheimer's disease through a thorough, non-invasive eye examination. The researchers base themselves on the eye/brain interconnection.

Alzheimer's disease is a chronic neurodegenerative disease that destroys brain cells, which over time causes deterioration of memory and thinking skills. It is a disease that will one day affect all aspects of a person's life: the way they think, feel and act.

Only rare cases of Alzheimer's disease are hereditary, and represent less than 5% of all cases. Genetic testing is available for families with a history of this form of the disease.

Alzheimer's disease is the most common form of dementia and could contribute to 60-70% of cases. Warning signs of Alzheimer's disease include minor memory problems, such as forgetting new information and difficulty performing familiar tasks.

 

Over the years, research has multiplied to find ways to mitigate and slow the progression of the disease and symptoms. Other research is also looking at a possible treatment for the disease.

In this article, the two theories that we will detail relate to early detection of the disease through thorough and non-invasive eye examinations. Indeed, the interconnection between the eyes and the brain would allow screening well before the appearance of clinical symptoms of the disease and before any signs are visible on an MRI.

 

Vitreous Humor Analysis Study:

This study concerns the analysis of ocular fluid in which certain biomarkers (proteins or molecules) could be highlighted. These same biomarkers are also found in blood and cerebrospinal fluid (around the brain and spinal cord).

 

To learn more about this study:

https://alzres.biomedcentral.com/articles/10.1186/s13195-020-00677-4

 

 Retinal vasculature study:

This other study focuses on the modification of the density of the network of blood vessels present in the retina in people with Alzheimer's disease.

In a healthy subject, microscopic blood vessels form a dense network at the back of the eye. While in a sick subject the density would be much less pronounced over time. This loss of blood vessel density in the retina could be an early signal of the onset of the disease.

Of course, a regular eye exam is not enough to detect these changes. The study implemented this analysis via OCT-angiography. These are high resolution images obtained by light waves that reveal the blood flow in each layer of the retina without the use of contrast medium. This allows an analysis of the retinal vasculature which could highlight changes in the vessels before visibility on MRI.

 

To learn more about this study:

https://www.sciencedirect.com/science/article/abs/pii/S2468653018306699?via%3Dihub

 

Many researchers, optometrists and eye care professionals agree that the eyes are a window into people's overall health.

 

Of course, many studies on this subject will still be needed for a generalization of this screening process to be possible.

 

 

To learn more about Alzheimer's disease:

https://alzheimer.ca/en/about-dementia/what-alzheimers-disease