A study by Inserm and CNRS, the results of which were communicated to the press on Wednesday, September 4, suggests a process to slow down age-related macular degeneration (AMD).
A drug used against Parkinson’s disease could delay one of the forms of age-related macular degeneration (AMD), the leading cause of visual impairment in those over 50, according to a study published by Inserm.
AMD is an eye disease corresponding to a degradation of a part of the retina (the macula). If the peripheral part remains intact, this pathology is nonetheless very disabling because it can lead to the loss of central vision.
Two forms of the disease have roughly equivalent prevalence: the neovascular form, called “exudative” or “wet”, and the atrophic or “advanced dry” form.
While the dry form currently has no treatment, the neovascular form can be slowed down by regular injections into the eye. But given the severity of the treatment, alternatives are desirable.
Epidemiological studies have already highlighted a possible association between Parkinson’s disease and a reduced risk of neovascular AMD.
In a new study, published this summer in the journal “The Journal of Clinical Investigation”, researchers from Inserm, CNRS, and Sorbonne University at the Vision Institute wanted to understand the mechanisms explaining this potential protection.
Further studies needed
In cellular and animal models, they showed that L-Dopa, a drug from the dopaminergic family used in the treatment of Parkinson’s disease, activates a specific receptor in the brain, called DRD2. This activation of DRD2 blocks the formation of new blood vessels in the eye, a key process in the development of neovascular AMD.
The team then analyzed health data from more than 200,000 patients with neovascular AMD in France: those who took L-Dopa or other drugs that inhibit the DRD2 receptor to treat their Parkinson’s disease developed neovascular AMD later in life and required fewer injections.
These patients declared the disease at 83 years of age, instead of 79 years of age for the others.
Further clinical studies will be needed to confirm these results, the researchers acknowledge.
But, for the wet form of the disease, “we now have a serious lead to delay its progression and reduce the burden of current treatments,” commented Florian Sennlaub, Inserm research director at the Vision Institute, quoted in a press release.
