Look into my eyes ... you have Alzheimer's ...

We have discussed many times the importance of early detection of Alzheimer's disease.  It is in the early stages, perhaps years before symptoms appear, that interventions are thought to be most effective.  This includes lifestyle interventions, but it will also likely be the case with drug interventions, such as the now-promising aducanumab.

Also, early (and accurate) detection is important to Alzheimer's research.  The younger a test subject is, the less likely the test results are to be confused by other brain pathologies that emerge as we get older.  People (like me) who first display symptoms at 65 or older, likely were already developing the disease at 50.  But so far, there is no reliable test to identify the disease at this age.

We seem to be on the verge of FDA approval of one or more blood tests for early detection of Alzheimer's disease.  These will look for the presence of beta amyloid in a blood sample.  Beta amyloid in the blood has been found to correspond to the development of Alzheimer's disease.  But are there other ways of detecting the amyloid?  It seems there is at least one other.

A research study published in the November 20, 2019 issue of the journal ACS Chemical Neuroscience described a process for identifying beta amyloid in the retina of the eye.  The researchers found that, when they shone a light on the retina, the beta amyloid molecules (due to their unique shape and small size) scattered the light in a peculiar way.  This type of scattering is called Rayleigh scattering, and it is what causes scattered sunlight in the sky to present as the color blue.  In the case of the sky, the blue light is scattered across the sky by the small air molecules.  The small amyloid molecules can apparently do something similar with light shone on the retina.

Once fully developed, it seems this process will provide an easy and (relatively) inexpensive way of identifying the onset of Alzheimer's disease early in the pathology.  It may resemble the test you get for glaucoma at your optometrist. 

So what is to be done with this development?  In a recent announcement, the Canadian AI medical imaging company, Retispec, announced that they are partnering with Gentex Corporation to develop the technology and move it into use.  Gentex engineers and manufactures electro-optical equipment for a variety of industries -- such as the device that dims the rear view mirror in your car at night. 

How long will this take to bring an approved device to market?  I don't know, and I didn't get any insight from the literature the partnership has released.  Considering how advanced the blood tests seem to be (just awaiting FDA approval), I think the blood tests will be available first.