Drugs like Ozempic have been linked to a rare form of sudden and incurable blindness.

Boston eye doctors have begun to notice a small but alarming increase in cases a rare type of sudden blindness in patients taking semaglutide.

Questions are being raised about whether taking Ozempic or Vegovi could cause an increase in cases Non-arteritic anterior ischemic optic neuropathya rare condition in which blood flow to the optic nerve is cut off, disrupting communication between the eye and the brain. The problem usually appears suddenly, without pain, and causes people to They wake up in the morning unable to see out of one eye..

A new study published Wednesday in JAMA Ophthalmology found that people taking semaglutide were slightly more likely to develop NAION than other patients with obesity or diabetes. (Semaglutide is the active ingredient in two Novo Nordisk drugs: Ozempic for type 2 diabetes and Vegovi for obesity.)

rare and noticeable

The number of patients taking semaglutide who developed NAION was small: of more than 16,000 Massachusetts eye patients included in this six-year retrospective study, only 37 people taking semaglutide developed NAION.

But that was more than four times as many eye problems as similar patients who didn’t take the drugs for the same period of time. Only nine people with diabetes or obesity who didn’t take semaglutide developed NAION, the researchers found.

“This is information we haven’t had before and should be included in conversations between patients and their doctors, especially if patients have other known optic nerve problems, such as glaucoma, or if there was significant pre-existing vision loss from other causes,” Dr. Joseph Rizzo, lead author of the study, director of the neuro-ophthalmology service at Mass Eye and Ear and a professor of ophthalmology at the School of Medicine, said in a Harvard news release.

“The use of these drugs has increased dramatically in industrialized countries and they have provided very significant benefits in many ways, but future conversations between the patient and their doctor should include NAION as a potential risk,” he added.

Novo Nordisk’s refusal

In a statement sent Business Insider, Semaglutide manufacturer Novo Nordisk said: “Patient safety is a top priority for Novo Nordisk and we accept all reports regarding side effects received use of our products.

But the drug company raised concerns about how the study was conducted, saying there were too few cases in the study to draw meaningful conclusions and that this type of retrospective study could never answer questions about a causal link between semaglutide and this type of blindness.

“NAION does not cause adverse reactions to marketed semaglutide products,” the company said.

Patients with diabetes and hypertension have always had a higher risk of developing vision problems. For example, there are chronically high blood sugar This can distort the lens of the eye, contributing to blurred vision. (Novo Nordisk is working on another independent study to see if semaglutide might be useful in treating diabetic retinopathy.) NAION is usually permanent and has no cure.