A recent study has uncovered a potentially serious risk associated with weight loss injections that could lead to an eye disease, which can result in blindness. The study found that individuals with diabetes who were prescribed semaglutide – better known under the brand names Wegovy and Ozempic – were more than four times as likely to be diagnosed with non-arteritic anterior ischemic optic neuropathy (NAION).
NAION is a condition where the arteries supplying blood to the optic nerve in the eye become blocked. This can result in vision loss as the optic nerve is deprived of oxygen and subsequently damaged. There is no known treatment for the condition, which affects 10 out of 100,000 people in the general population.
The research, published in the journal JAMA Ophthalmology and conducted by researchers from Harvard University, analyzed data from 16,827 patients at Mass Eye and Ear, a Harvard teaching hospital, who received treatment over a six-year period. Of the included patients, 710 had type 2 diabetes, of which 194 had been prescribed semaglutide. Among these patients, there were 17 cases of NAION in those on semaglutide, compared to six cases in those on other diabetes medications. Over three years, 8.9% of these individuals on semaglutide developed NAION compared to 1.8% on other medications.
The study also found that individuals who were overweight or obese and were prescribed semaglutide were more than seven times as likely to develop the condition compared to those on other types of weight loss medication. Among these overweight or obese patients, there were 20 cases of NAION in those on semaglutide, compared to only three cases in those using other weight loss medications. Over three years, 6.7% of these individuals on semaglutide developed NAION compared to 0.8% on other weight loss medications.
Professor Joseph Rizzo, professor of ophthalmology at Harvard Medical School, said: “Our findings should be considered significant but preliminary, as future studies are needed to investigate these questions in a much larger and more diverse population. This is information we did not have before and should be included in discussions between patients and their doctors, especially if patients have other known optic nerve issues such as glaucoma, or if there is existing significant vision loss from other causes.”
Graham McGeown, honorary professor of physiology at Queen’s University Belfast, added: “This research suggests an association between semaglutide treatment and a form of vision-threatening optic neuropathy, but this should ideally be tested in larger studies. Considering the rapid increase in the use of semaglutide and its potential approval for a range of issues beyond obesity and type 2 diabetes, this issue deserves further investigation, but potential drug side effects should always be weighed against likely benefits.”
A spokesperson for Novo Nordisk, the manufacturer of Ozempic and Wegovy, said: “Patient safety is a top priority for Novo Nordisk, and we take all reports of side effects from the use of our medicines very seriously. Non-arteritic anterior ischemic optic neuropathy is not listed as a known side effect in the summary of product characteristics (SmPC) for the marketed formulations of semaglutide (Ozempic and Rybelsus for type 2 diabetes and Wegovy for weight control) according to the approved labels.”
This new knowledge should lead to increased awareness and discussion between doctors and patients, especially those with existing eye problems, about the risk of using semaglutide.