Parkinson’s early diagnosis – Simple eye test spots changes in retinal cells before brain symptoms appear
On 18 August we learned from the newspapers that consultant ophthalmologists, Dr Eduardo Normando and Professor Francesca Cordeiro, from the Western Eye Hospital and UCL Professor of Glaucoma and Retinal Neurodegeneration Studies, had published a fascinating study in Acta Neuropathologica Communications.
The study was about a possible way of detecting early Parkinson’s disease. Just to remind you, Parkinson’s disease is what Cassius Clay, AKA Mohammad Ali, had. It completely decimated his career as a boxer. It is a life-changing condition that interferes with everyday tasks. Victims cannot walk well. Their speech is difficult. It even makes fine hand movements difficult as their mental function deteriorates.
Albeit their studies were done in rats, it is certainly a step towards humans. Cordeiro and her colleagues discovered retinal changes of the eyes of rats with Parkinson’s disease.
We know that Parkinson’s patients have less sharp vision. The loss of dopamine affects the neurones in the eye retina. They get decreased sensitivity to contrast, colour and brightness. This shortage of dopamine has also damaged their brain cells. This causes tremors, muscle stiffness, slow movement, poor brain function and reduced quality of life.
By looking at the retina in a special way, the retinal ganglion cell changes and alterations in the thickness of the retina could be a predictor of the disease. Cordeiro believes that using these tests has a future for detecting the disease in humans and intervening much earlier.
They even went on to treat the animals with an anti-diabetic drug called Rosiglitazone. This drug helps protect nerve cells. They found evidence of reduced rat retinal cell death, as well as a protective effect on the brain. This suggests that particular anti-diabetic drug could treat Parkinson’s.
In summary, it is possible that in the future we will have a simple, non-invasive eye test that can help thousands of people. It’ll narrow down the number of cases that will progress. These tests, paired with newer drugs to treat Parkinson’s, will reduce the effects of dopamine depletion.