Blindness alarm from use of weight-loss drugs

Weight-loss drugs such as Ozempic may cause people to go blind, according to a new study.

A team at Harvard Medical School launched the study after doctors ‘noticed a disturbing trend’ of patients taking Ozempic suddenly going blind. Picture: AFP

Weight-loss drugs such as Ozempic may cause people to go blind, according to a new study.

Harvard researchers found that people taking semaglutide, also known by the brand name Wegovy, were significantly more likely to develop a rare and irreversible eye condition.

Non-arteritic anterior ischaemic optic neuropathy (Naion) can cause sudden blindness in one eye.

It rarely involves pain or discomfort and patients often only notice it on waking up.

Patients prescribed Ozempic for diabetes were four times more likely to be diagnosed with Naion; those given the drug for obesity were seven times more likely to develop vision loss.

A team at Harvard Medical School launched the study after doctors “noticed a disturbing trend” of patients taking Ozempic suddenly going blind. They looked at the records of 17,000 patients treated at Massachusetts Eye and Ear, a teaching hospital, over the six-year period since Ozempic became available to see if there was a link.

In overweight patients with type 2 diabetes, 8.9 per cent on semaglutide developed sudden blindness, compared to 1.8 per cent on other diabetes drugs.

In patients prescribed semaglutide for obesity, 6.7 per cent developed the eye condition, compared to 0.8 per cent of those not taking the drug.

The study, published in Jama Ophthalmology, is the first to identify that eye problems could be a side effect of the popular new drugs. The authors said from now on, doctors should warn patients of the “potential risk” of going blind before prescribing the drug.

Semaglutide is one of a new generation of powerful weight-loss medications that work by mimicking a hormone that makes you feel full. It was first prescribed in 2017 for diabetes.

Joseph Rizzo, the author of the study, from Harvard Medical School, said: “The use of these drugs has exploded ... 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 affects up to one in 10,000 people every year, so the overall risk remains low.

Experts are not sure why weight-loss drugs might cause the condition, which involves a blockage in the blood vessels supplying the optic nerves.

There is no treatment.

The findings will add to concerns about the potential harm of weight-loss injections. Other side effects include nausea, diarrhoea, kidney failure and inflammation of the pancreas.

Semaglutide is being taken by millions of people around the world, and manufacturer Novo Nordisk is struggling to keep up with demand. Recent trials have suggested the drug could also be used to treat heart and kidney disease. Novo Nordisk has been contacted for comment.

The Times