A recent study suggests imaging amyloid beta protein in the retina may be a less expensive and less invasive tool for diagnosing and monitoring the progression of Alzheimer’s disease (AD) in the brain.

Since the presence of amyloid beta in the brain is an indicator of AD—and the protein deposit count in the retina increases as the severity of the disease in the brain increases—a team of Canadian researchers sought to find a simpler way to diagnose the disease. Their paper was presented on Monday during the ARVO annual meeting.

The investigators studied donated eyes and brains with a variety of neurological disorders, including those diagnosed with AD. Retinal amyloid deposit counts found in the anterior retina with fluorescence and polarimetry signals were compared with brain tissue examined for anatomical distributions of amyloid beta deposits and tau-immunoreactive neurofibrillary tangles, in addition to being assessed for neuritic senile plaque numbers and a cumulative score of the severity of AD pathology.

They found brains with no AD pathology also had clear retinas; however, every brain with AD pathology also had amyloid beta deposits in the retina. In addition, “the count in the retina of deposits of this protein increased as the severity of the disease in the brain increased,” the researchers said in their ARVO abstract. “Therefore, imaging of these protein deposits in the living retina may be a promising, less expensive and less invasive tool for diagnosing and monitoring progression of AD in the brain.”

“As eye care providers, I think in the very near future we will routinely use the assessment of amyloid beta deposits in the retina for the confirmation and grading of severity of Alzheimer’s disease,” says Joseph P. Shovlin, OD, of Scranton, PA. “Counting deposits of protein in the retina with appropriate technology such as modified OCTs should prove to be less expensive and invasive and more cost effective than currently employed methods used in the lab.”

Corapi F, Campbell MC, Emptage L, et al. Correlation between amyloid beta deposits in ex vivo retinas and severity of Alzheimer’s brain pathology. ARVO 2018. Abstract 1582.