Polarized light scanner detects Alzheimer’s before symptoms appear

The link between amyloid proteins and Alzheimer's disease is well established. Unfortunately, these structures are often only detectable once the disease has progressed to a relatively late stage. But researchers are developing a noninvasive eye scanning technology that may be capable of detecting Alzheimer's in its earliest stages.

The diagnostic tool uses polarized light to show amyloid protein deposits in the back of the retina, allowing for detection well before symptoms appear.

"Polarization imaging is promising for noninvasive imaging of retinal amyloid deposits as a biomarker of Alzheimer's," said Melanie Campbell, of Waterloo's Department of Physics and Astronomy, who led the research team. "The ability to detect amyloid deposits in the retina prior to disease symptoms may be an essential tool for the development of preventative strategies for Alzheimer's and other dementias."

Being able to identify the amyloid protein gives researchers a quicker start in combating symptoms before they appear. The polarized light scans are as sensitive as other methods and can be done without irritating dyes, making it both cost effective and convenient, with the potential to be used as an in-office screening tool.

"Early diagnosis is important, especially since treatment options are more limited later in the disease," said Campbell. "Widely available, inexpensive, early detection of amyloid would help researchers develop more effective treatments before the onset of symptoms."