Alzheimer's Disease, the most common form of dementia, affects an estimated 35 million people worldwide. Scientists at Australia's CSIRO have released promising preliminary results for a test that can detect Alzheimer's before onset of the disease.
It's believed that Alzheimer's disease is caused by a build-up of a protein called beta-amyloid in the brain. The protein may disrupt the connections within the hippocampus, the section of our brains involved in memory formation. Scientists have devised a simple test to check for presence of the protein.
The trial involved 200 volunteers who made two visits to to the McCusker Alzheimer's Research Foundation in Perth, Western Australia. Scientists used a specialised camera developed by US company NeuroVision Imaging LLC and software developed at Cedars-Sinai Medical Centre in LA.
In between visits, the volunteers were given a dietary supplement containing curcumin, the compound that gives turmeric its bright yellow colour. Circumin binds to the beta-amyloid proteins in the retina which then show in the second scan as fluorescent spots. The size and quantity of the spots are then measured to create a 'retinal amyloid index' for each patient and compared to other indicators of Alzheimer's Disease.
Levels of beta-amyloid found in the retina reflect the levels found in the brain and offer an easier 'diagnostic window' according to CSIRO's Dr Shaun Frost. Dr Frost explains, "the hope is that one day a screening test of Alzheimer's Disease could be delivered as part of routine eye tests."
Currently sufferers are diagnosed after symptoms have already presented themselves, and by then irreversible brain damage has already occurred. As there is no cure, current treatment can only aim to slow down further cognitive decline.
These eye scans can pick up smaller buildups of beta-amyloid plaque and have the potential to diagnose patients up to 20 years earlier than current diagnostic techniques. Jason Burton from Alzheimer's Australia points out the importance of these findings.
"If we can identify people pre-symptomology then it gives us a new route into finding new test medications."
As there are no medications designed to prevent the onset of Alzheimer's this test would be the first in several steps towards making the prevention of Alzheimer's better than finding a cure.