Prolonged anticholinergic drug use may be associated with a risk of late age-related macular degeneration, according to a study.
A dose-effect relation was also observed.
Anticholinergic drugs (ACDs), such as bronchodilators and anti-Parkinson agents, are often used by older patients with the specific aim of blocking the effect of acetylcholine at the muscarinic receptor level within specific organ systems. Other commonly used medications have unintended anticholinergic effects, including antidepressants and first-generation antihistamines. Reduced cholinergic transmission is suspected to increase brain amyloid- deposits, which are found in AMD drusen.
A study, which included four ophthalmology centers in France, investigated the potential association between ACD exposure and the risk of late AMD. It included 200 patients with late AMD and 200 controls.
Overall, 26 cases (13%) vs. 10 controls (5%) were exposed to ACDs for at least 3 months, suggesting an association between these drugs and the development of late AMD. This association was confirmed after adjusting for other AMD risk factors such as smoking, obesity and alcohol intake. Greater association with AMD was found with longer cumulative ACD exposure.
“Several mechanisms may be suggested to explain the association of ACD use and AMD. One is the increase in macular inflammation owing to retinal amyloid-ß deposition secondary to ACD use. Anticholinergic drug use is suspected to increase brain amyloid-ß deposition,” the authors wrote.
In addition, mydriasis induced by ACDs might lead to greater exposure of the retinal pigment epithelium to ultraviolet radiation.
“Further studies are needed to confirm this association and assess potential causative pathways between ACD use and late AMD,” the authors concluded. – by Michela Cimberle
Disclosure: Aldebert reported no conflict of interest. Please see the study for the other authors’ financial disclosures.