Scientists believe they've made a huge breakthrough in the fight against Alzheimer's, a simple eye test that could detect the condition 20 years before patients start to show symptoms.
Eyes, window on the soul, and now they could prove more revealing than ever. Best-selling author Terry Pratchett has Alzheimer's. "It loses things for you. It moves things in different places. I forget where I put things down the moment that I put them down. Lots of people spend a lot of time bouncing around, wondering what is happening. But there is an explanation. I believe in a way that knowledge is a kind of power. You know what you've got. At least you can work out your future around that."
Most people don't realize the retina is a direct extension of the brain. So with the right test, it can discover Alzheimer's years before symptoms. And that's crucial because many treatments rely on being used early. Lasers are scanning my iris, magnified here. A special marker can attach the dead cells, potentially leading to early diagnosis.
Francesca Cordeiro, professor institute of ophthalmology, ucl. "The nerve cells that are in the brain, you find exactly the same sorts of cells in the retina. The difference between the brain and the retina are, in the brain, you can't see because of the bone."
Trials of the new Alzheimer's test on humans could start next year. Here, the image on the right screen shows a healthy retina. On the left, speckles of color show how the test highlights dying cells. A warning up to 20 years before symptoms could give sufferers a better chance with a disease that takes so much.
