January 15, 2010
Eye Exam Could Spot Alzheimer’s Early
British scientists are currently developing a test that can detect Alzheimer's up to 20 years before any symptoms show, the Daily Mail UK reported.
Experts say that in as little as three years, the simple and inexpensive eye test could be part of routine examinations by opticians, allowing those in middle age to be screened.
The University College London researchers that are developing the technique say it could also speed up the development of medication capable of stopping the disease in its tracks, preventing people from ever showing symptoms.
"These findings have the potential to transform the way we diagnose Alzheimer's, greatly enhancing efforts to develop new treatments," said Rebecca Wood of the Alzheimer's Trust.
While there is no cure for Alzheimer's and existing drugs do not work for everyone, current diagnosis is based on memory tests, and expensive brain scans are also sometimes used.
Decisive proof of the disease usually comes from an examination of the patient's brain after death.
However, the eye test would provide a quick, easy, cheap and highly accurate diagnosis.
The procedure exploits the fact that the light-sensitive cells in the retina at the back of the eye are a direct extension of the brain. UCL researchers showed for the first time in a living eye that the amount of damage to cells in the retina directly corresponds with brain cell death.
The researchers have also revealed the pattern of retinal cell death characteristic of Alzheimer's. And each diagnosis has been right every time.
Studies in the past have shown that cells start to die ten to 20 years before the symptoms of Alzheimer's become evident, which could allow people to be screened in middle age for signs of the disease.
But many people may not want to know their fate so far in advance and there is also the fear that insurance companies could increase premiums for those who test positive while still young.
So far, the experiments have only been performed on lab animals, but the team is ready to begin the first human trials.
"The equipment used for this research is essentially the same as is used in clinics and hospitals worldwide. It is also inexpensive and non-invasive, which makes us fairly confident that we can progress quickly to its use in patients," said researcher Francesca Cordeiro.
The study, reported in the journal Cell Death & Disease, contends that it is entirely possible that in the future a visit to an optician to check on eyesight will also be a check on the state of the brain.
Cordeiro believes the technique could also improve the diagnosis of other conditions, including glaucoma and Parkinson's disease.
An early diagnosis would give patients and their families much more time to prepare for the future, while it would also allow patients with new drugs that stop the disease in its tracks to reach their full potential.
"If you give the treatment early enough, you can stop the disease progressing, full stop," Cordeiro said.
"This research is very exciting. If we can delay the onset of dementia by five years, we can halve the number of people who will die from the disease," said Dr. Susanne Sorensen of the Alzheimer's Society.
However, she cautioned that the test was still experimental but holds promise.
On the Net: