Can Parkinson’s disease be detected with an eye exam?
Alzheimer’s disease, autism, schizophrenia and traumatic brain injury. They are already used to detect predispositions to physical-health problems like high blood pressure and diabetes. On August 21st researchers at Moorfields Eye Hospital and University College London’s Institute of Ophthalmology published a paper in which they said they had identified markers of Parkinson’s disease in the eye seven years before it would have been apparent using existing tests.
How? Changes in the eye, particularly the retina, sometimes appear to reflect changes in the brain. The retina is like a piece of wet tissue paper at the back of the eye that contains light-sensitive nerve cells in many distinct layers. It grows from the same tissue as the brain during embryonic development and is connected to the brain by the optic nerve.
It thus shares many of the brain’s characteristics. If a relationship between brain and retina were proved, it could be extremely useful: brains are difficult to study while their owners are alive. Eyes, on the other hand, are easy to scan in detail with equipment found in the average high-street optician’s office.
The technique in question is optical coherence tomography (OCT), a non-intrusive 3-D scan that works by bouncing light waves across the eye, and taking pictures of the retina and each of its layers, which are then mapped and measured. Scientists have long suspected that the thinning of the retina may be an indicator of Parkinson’s. In the new paper, published in Neurology, researchers have shown this relationship in a fairly comprehensive way.
Read more on livemint.com
