Montreal – An examination of the retina could one day allow an early screening of Parkinson’s disease, which would lead to care more hasty of patients who need it, lead to believing work carried out at Laval University.
Professor Martin Lévesque and his team have found that the neurons of the retina of patients suffering from the parkinson react differently to light signals than those of the health of healthy patients.
“We have really discovered a signature that would be specific to patients with Parkinson,” said Mr. Lévesque, who is a professor at the Faculty of Medicine at Laval University and researcher at the Cervo Research Center.
The results are all the more promising as they were obtained by comparing only twenty patients who have received a diagnosis of Parkinson for less than five years to twenty health subjects, he said. “We were pleasantly surprised to (…) detect significant differences with only twenty patients”.
Inspired by the work of some of their colleagues who had used an electroretinography to study schizophrenia and major depression, the researchers installed an electrode on the lower eyelid of each participant and recorded the response of the retina to a series of flashes of intensities, frequencies and different colors. They did the same with people of the same age, but healthy.
The lines obtained for people with Parkinson had a signature distinct from that of the people of the control group. Similar results were obtained during tests in transgenic mice overexpressing a human protein associated with Parkinson’s disease.
-The retina is a direct extension of the central nervous system. It therefore offers a non-invasive way to explore the brain and an unusual response from the retina to luminous stimuli could be indicative of a pathology that touches the brain, it was explained by press release.
At the moment, Parkinson’s final diagnosis only occurs after the patient’s death, during an examination of his brain, added Mr. Lévesque. And when the patient consults his doctor for the first time because the first neurological symptoms appeared, the disease is already installed and the irreversible degeneration started for several years.
“Often, when the patient goes to the clinic for the first time, he has already lost a good part of his dopaminergic neurons,” said Lévesque. This is what induces motor symptoms such as tremors or muscle rigidity. And when these neurons are lost, they are not replaced. ”
The discovery of biomarkers making it possible to detect the disease in a hasty way would therefore be of crucial importance, since this could greatly improve the patient’s prognosis.
This discovery could one day make it possible to provide screening for Parkinson’s disease to the whole population from the age of 50. It could also lead to an objective measure of the progression of the disease or the way it responds to the treatments.
The conclusions of this study were published by the medical newspaper Neurobiology of Disease.
