Eyes may hold early signs of Alzheimer's: study

Scientists have identified a way that can be used to detect early signs of Alzheimer's disease by looking at the back of patients' eyes.
A new study from The University of Texas Medical Branch at Galveston in the US offers important insight into how Alzheimer's disease begins within the brain.
The researchers found a relationship between inflammation, a toxic protein and the onset of the disease.
"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," said Ashley Nilson, a neuroscience graduate student at UTMB.
"Using the retina for detecting AD and other neurodegenerative diseases would be non-invasive, inexpensive and could become a part of a normal screening done at patient checkups," said Nilson.

Researchers have previously found evidence that a toxic form of tau protein may underlie the early stages of Alzheimer's.

Brain cells depend on tau protein to form highways for the cell to receive nutrients and get rid of waste.
In some neurodegenerative diseases like Alzheimer's, the tau protein changes into a toxic form called tau oligomers and begins clumping into neurofibrillary tangles.
When this happens, molecular nutrients can no longer move to where they are needed and the oligomers produce toxic effects leading to the eventual death of the brain cells.
It is becoming increasingly clear that inflammation within the brain plays an important role in Alzheimer's development and progression, researchers said.

Inflammation and loss of connections between nerves within the brain happen before the formation of the tangles that are characteristic of this disease. It is possible that the tau oligomers may be responsible for this inflammation.
The research team investigated the relationship between inflammation, toxic tau and Alzheimer's onset by performing systematic analyses of brain and retina samples from people with Alzheimer's and a mouse model of Alzheimer's.
The results demonstrated that the toxic tau may induce inflammation in Alzheimer's. The toxic tau spreads between connected brain regions, which may initiate inflammation in these new regions.
This situation can create a cycle of toxic tau, inflammation and cell death throughout the brain over time.

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, researchers said.
Researchers found that retina tissue that they studied can show evidence of toxic tau and inflammation.
The research was published in the Journal of Alzheimer's Disease.