Researchers have zeroed in on yet another possible ocular concern for diabetes patients who take popular GLP-1 therapies.
A recent study, published in JAMA Ophthalmology and conducted by University of Toronto researchers, found that diabetes patients who use GLP-1 drugs were twice as likely to develop neovascular age-related macular degeneration (nAMD) compared to their peers who don’t take the meds.
AMD is a leading cause of irreversible blindness in older adults, affecting some 196 million people as of 2020, the study authors said. While atrophic AMD, also known as dry AMD, is more common, the neovascular form of the disease (the “wet” form) is more severe and often leads to rapid, permanent vision loss.
The findings were collected after researchers evaluated the health data of 139,002 diabetes patients in Canada, all of whom were 66 years or older and either used a GLP-1 drug for more than six months or not at all. The patients were sorted into a 1:2 matched cohort, with researchers analyzing more than 46,000 patients who had used GLP-1s and more than 92,668 who hadn’t.
Over three years of follow-up between 2020 and 2023, 0.2% (93 patients) of those in the GLP-1 user group were diagnosed with nAMD, as were 0.1% (88 patients) in the contrasting group.
Of the GLP-1 group, 97.5% of patients were on Novo Nordisk’s popular diabetes and obesity GLP-1 semaglutide—sold as Wegovy, Ozempic and in oral form as Rybelsus—while 2.5% took Sanofi’s lixisenatide.
As it turns out, the risk of developing nAMD was quite low regardless of GLP-1 usage, the study authors acknowledged. Still, the risk became even higher for those who were on GLP-1s the longest. Other risk nAMD risk factors noted in the study include advanced age and a history or cerebrovascular accident.
“These findings expand upon the growing body of literature raising concerns regarding the potential ocular safety of systemic GLP-1 RA use in patients with diabetes,” researchers wrote, although the findings importantly speak to “associations, rather than cause and effect."
Another previously noted ocular-related concern of the popular drugs is a potential risk factor for nonarteritic anterior ischemic optic neuropathy (NAION), a serious eye condition that causes vision loss due to decreased blood supply to the optic nerve.
After a study published in JAMA Ophthalmology last summer found that people taking Novo’s semaglutide for diabetes or weight loss were four to nearly eight times as likely to end up with NAION, the European Medicines Agency (EMA) took its own look at the possible safety risk.
On June 6, the EMA’s safety committee recommended that the product information for semaglutide be updated to include NAION as a “very rare” side effect that could affect up to 1 in 10,000 people.
The agency came to the conclusion after evaluating results from several large studies, and will now send its recommendation over to the Committee for Medicinal Products for Human Use (CHMP) before the European Commission makes its legally binding decision.