Weight-loss drug Ozempic linked to eye condition that can cause blindness in new study

People with diabetes prescribed semaglutide (sold under the brand names Wegovy and Ozempic) were more than four times more likely to be diagnosed with a condition called non-arteritic anterior ischemic optic neuropathy (Naion).

Meanwhile, people who were overweight or obese and prescribed the drugs were more than seven times as likely to develop the condition as those on other weight-loss medicines.

Naion, which is uncommon, occurs from a lack of sufficient blood flow to the optic nerve.

People typically suffer sudden vision loss in one eye, without any pain, and patients often notice the issue on waking up.

There are no current treatments for Naion and vision often does not improve.

The new study, published in JAMA Ophthalmology, was led by Joseph Rizzo, a professor of ophthalmology at Harvard Medical School in the US.

He said: “The use of these drugs has exploded throughout industrialised countries and they have provided very significant benefits in many ways, but future discussions between a patient and their physician should include Naion as a potential risk.”

Naion is thought to affect 10 out of 100,000 people in the general population.

Prof Rizzo and colleagues decided to investigate a potential link between semaglutide and Naion last summer after three patients in his practice were diagnosed with vision loss caused by Naion in one week. All the patients were taking semaglutide.

To investigate possible links, researchers examined data from more than 16,000 patients from Mass Eye and Ear (a Harvard teaching hospital) treated over a six-year period.

They compared patients who had received prescriptions for semaglutide with those taking other diabetes or weight-loss drugs.

Among 16,827 patients, 710 had type 2 diabetes, with 194 prescribed semaglutide. A total of 979 patients were overweight or obese, with 361 prescribed semaglutide.

In people with type 2 diabetes, 17 Naion events occurred in patients prescribed semaglutide compared to six on other diabetes drugs. Over three years, 8.9pc people on semaglutide had Naion compared to 1.8pc on the other drugs, the researchers found.