Study links popular weight loss drugs to rare blinding eye condition

Popular weight loss drugs have been linked to an uncommon eye-blinding condition, according to a new study.

Patients with diabetes or obesity are commonly prescribed weight loss drugs, such as Ozempic or Wegovy, containing the protein semaglutide, which helps manage blood sugar by promoting production of insulin.

A team of researchers, led by those from the Massachusetts Eye and Ear hospital, US, found that patients with obesity who were prescribed these weight loss drugs were over seven times more likely to be diagnosed with NAION, or 'Non-Arteritic Anterior Ischemic Optic Neuropathy', causing sudden vision loss in one eye.

They also found that patients with diabetes who were taking these semaglutide-containing drugs were over four times likely to be get a NAION diagnosis. The findings are published in The Journal of the American Medical Association (JAMA) Ophthalmology.

"This information we did not have before and it should be included in discussions between patients and their doctors, especially if patients have other known optic nerve problems like glaucoma or if there is pre-existing significant visual loss from other causes," lead author Joseph Rizzo, director of the Neuro-Ophthalmology Service at Massachusetts Eye and Ear, said.

Rizzo stressed that the increased risk relates to a relatively uncommon disorder and further studies are needed as the researchers do not know why or how the link between taking weight loss drugs and the eye condition exists.

The findings should, therefore, "be viewed as being significant but tentative," Rizzo said.

NAION is relatively rare, affecting 2-10 people per one lakh population, according to the American Academy of Ophthalmology. The condition is thought to be caused by reduced blood flow to the optic nerve head, leading to permanent loss of vision in one eye.

In their analysis, the researchers included data from records of more than 17,000 patients at the hospital diagnosed with either diabetes or obesity, who were prescribed semaglutide-containing or other weight loss drugs.

"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," Rizzo said.