People looking to slim down were warned today that weight-loss injections could trigger a worrying eye disease that causes blindness.
Semaglutide, available as Ozempic and Wegovy, has been hailed as a monumental breakthrough in the war on obesity.
But according to American experts, people with diabetes are prescribed Patients on semaglutide were four times more likely to be diagnosed with non-arteritic anterior ischemic optic neuropathy (NAION).
And overweight or obese people taking the drugs were seven times more likely to develop the condition, known as “ocular stroke,” than those taking other weight-loss medications.
The researchers called the findings “significant but tentative” and urged doctors to warn patients of the risk, especially if they suffer from “other known optic nerve problems, such as glaucoma.”
Ozempic is available on the NHS as a treatment to control blood glucose levels in people with type 2 diabetes. Last May, it was also approved for weight loss under the brand name Wegovy and was launched on the NHS in September for weight loss in overweight or obese patients with weight-related health problems.
Teacher Joseph Rizzo, an ophthalmology expert at Harvard Medical School He said: ‘The use of these drugs has skyrocketed in industrialized countries and they have provided very significant benefits in many ways.
‘But future discussions between a patient and his or her doctor should include NAION as a potential risk.
“It is important to note, however, that the increased risk is associated with a disorder that is relatively rare.”
NAION, which affects about one in 10,000 people, occurs when the vessels that supply blood to the optic nerves become blocked.
Loss of blood supply deprives the optic nerve of oxygen and causes damage to all or part of the nerve.
But unlike other strokes caused by a loss of blood supply, there is no weakness, numbness or loss of speech.
People usually experience a sudden loss of vision in one eye, without any pain, and patients often notice the problem upon waking up.
There are currently no treatments for NAION and vision often does not improve.
Researchers at Harvard University began investigating a possible link last summer after three patients taking semaglutide were diagnosed with the disease within a week.
They examined data from more than 16,000 patients at Harvard University’s Massachusetts Eye and Ear Hospital treated over a six-year period.
Of these, 710 had type 2 diabetes and 194 were prescribed semaglutide, and 979 patients were overweight or obese and 361 were prescribed semaglutide.
In people with type 2 diabetes, researchers recorded 17 cases of NAION in patients prescribed semaglutide, compared with six in those prescribed other diabetes medications.
During a three-year follow-up, 8.9 percent of those taking semaglutide were diagnosed with the disease, compared with 1.8 percent of those taking the other drugs, they found.
Meanwhile, in overweight or obese patients, 20 NAION events occurred in people prescribed semaglutide, compared with three in those given other medications.
About 6.7 percent of people taking semaglutide had NAION, compared with 0.8 percent taking other medications.
Wegovy and Ozempic work by stimulating the body to produce a hormone called GLP-1 that is naturally released from the intestines after meals.
Writing in the diary, However, the JAMA Ophthalmology researchers acknowledged that the number of NAION cases observed was relatively small.
Professor Rizzo added: “Our findings should be considered significant but tentative, as future studies are needed to examine these issues in a much larger and more diverse population.
‘This is information we didn’t have before and should be included in discussions between patients and their doctors, especially if patients have other known optic nerve problems, such as glaucoma, or if there is significant pre-existing visual loss from other causes.’
Meanwhile, Graham McGeown, honorary professor of physiology at Queen’s University Belfast, added: ‘This research suggests an association between semaglutide treatment and a vision-threatening form of optic neuropathy, but this would ideally need to be tested in larger studies.
‘Given the rapidly increasing use of semaglutide and its potential approval for a variety of problems other than obesity and type 2 diabetes, this issue merits further study, but the potential side effects of the drug always need to be weighed against the likely benefits.’
Novo Nordisk, which makes Wegovy and Ozempic, has been contacted for comment.
This comes weeks after NHS England’s medical director warned that the drugs can be dangerous and should not be seen as a “quick fix” for people who “just want to lose a few pounds”.
The announcement comes weeks after the NHS England’s medical director warned that the drugs can be dangerous and should not be considered a “quick fix” for people who “just want to lose a few pounds”. Professor Sir Stephen Powis (pictured) said the drugs should only be used to treat obesity or diabetes and should not be overused by holidaymakers trying to get “beach ready”, following growing concerns about people being treated in A&E after taking the drug.
Professor Sir Stephen Powis said the drugs should only be used to treat obesity or diabetes and should not be overused by holidaymakers trying to get “beach-ready”, following growing concern about people being treated in A&E after taking the medication.
The revolutionary injections have been hailed by the likes of Elon Musk and Jeremy Clarkson.
Ministers plan to give the drug to millions of overweight Britons to cut the country’s bloated welfare bill. Children could also be given the jabs.
Like any medication, semaglutide may have known side effects that vary in both frequency and severity, including nausea, constipation, diarrhea, fatigue, stomach pain, headaches, and dizziness.
Some patients have also experienced hair loss while using them.
The latest NHS data shows that 26 per cent of adults in England are obese and a further 38 per cent are overweight but not obese.
Experts have pointed to a lack of exercise and poor diets high in ultra-processed foods as the main drivers of the UK’s obesity epidemic.