The researchers found that the retina tissue shows evidence of toxic tau and inflammation -- crucial for the onset of the neurodegenerative disease.
"Using the retina for detecting Alzheimer's disease and other neurodegenerative diseases would be non-invasive, inexpensive and could become a part of a normal screening done at patient checkups," said lead author Ashley Nilson, graduate student at The University of Texas Medical Branch at Galveston.
The study demonstrated that the toxic tau, which spreads between connected brain regions, may initiate inflammation in brain regions.
In Alzheimer's, the tau protein changes into a toxic form called tau oligomers and begins clumping into neurofibrillary tangles, which can leading to the eventual death of the brain cells.
"Our findings suggest that the degeneration of nerve cells due to chronic inflammation induced by the tau oligomers may be combated through the combination of anti-tau oligomer and anti-inflammatory therapeutics for the treatment of Alzheimer's and related diseases," added Rakez Kayed, Associate Professor at The University of Texas Medical Branch.
This situation can create a cycle of toxic tau, inflammation and cell death throughout the brain over time.
For the study, the team performed a systematic analyses of brain and retina samples from people with Alzheimer's and a mouse model of Alzheimer's.
"Early detection of Alzheimer's warning signs would allow for early intervention and prevention of neurodegeneration before major brain cell loss and cognitive decline occurs,"Ms Nilson said.
Beyond determining eye health and corrective lens prescriptions, having an eye exam can alert health care professionals of several different health conditions including diabetic complications, high cholesterol and high blood pressure, the researchers suggested, in the paper in the Journal of Alzheimer's Disease.