Harvard research shows weight loss drug Ozempic is associated with rare vision loss, Novo Nordisk plunges 4.8%

Novo Nordisk's popular weight-loss drugs Ozempic and Wegovy have been linked to an increased risk of a rare vision loss condition - non-arteritic anterior ischemic optic neuropathy (NAION). Doctors at Massachusetts Eye and Ear, an affiliate of Harvard University, found that patients using these drugs had a significantly higher risk of developing NAION compared to those using other medications.

On July 3rd, Eastern Time, research showed that patients using Ozempic and Wegovy for weight loss had over seven times the risk of developing NAION compared to those using other weight-loss drugs; and when used for diabetes treatment, this risk was four times higher than other treatment methods. This finding was published this Wednesday in the "Journal of the American Medical Association Ophthalmology".

However, this study is limited in scope, based only on patient records from Massachusetts Eye and Ear Hospital, with a total of 37 cases of eye disease involved, making its statistical power limited. Therefore, researchers from Harvard University and other experts state that the current study results are not sufficient to prove that these drugs directly cause eye complications, and further large-scale validation is needed in more hospitals.

Neuro-ophthalmologist Susan Mollan from Birmingham, UK, stated: "I don't think this study is enough to make patients stop taking the medication." She pointed out that the direct causal relationship between drug use and eye complications cannot be proven at present, as some cases occurred months after starting the medication. However, doctors have a responsibility to fully inform patients of the potential risks, especially those with some degree of vision loss.

Novo Nordisk and its competitor, Li Auto, have seen high demand for their weight-loss drugs, leading to supply shortages in the market, and both companies are working to address this issue. Semaglutide, the main ingredient in Ozempic and Wegovy, has been studied for over 15 years, with its safety generally recognized in the scientific community. However, as the use of these drugs expands, researchers are closely monitoring for any new side effects.

On Wednesday, Novo Nordisk's ADR plunged over 4.8%, hitting a new low since June 4th.

The current study is expanding its scope to include more hospitals

At Massachusetts Eye and Ear Hospital, a series of unusual cases have raised concerns among doctors, with some patients taking semaglutide experiencing NAION, a rare condition that typically leads to permanent partial vision loss. Approximately 1 in 10,000 to 1 in 50,000 people are affected each year, with no standard treatment currently available Drug safety researcher Mahyar Etminan from the University of British Columbia, although not involved in this study, stated:

"We must carefully examine this potential risk. If this serious condition is indeed related to the medication, it will have a significant impact on our assessment of the risk-benefit ratio of the drug."

Etminan further pointed out that it is particularly important for those who take Wegovy for weight loss purposes without other symptoms to understand this risk. He emphasized that since diabetes itself is one of the risk factors for eye diseases, it is still unclear how Ozempic or Wegovy could trigger this condition.

This study covered records of 710 diabetic patients and 979 weight loss drug users treated at the Massachusetts Eye and Ear Infirmary since Ozempic was approved in December 2017. Researchers compared the incidence of NAION in patients who first used Ozempic or Wegovy with those using other treatment methods. It is worth noting that this study did not include Mounjaro and Zepbound, two diabetes and obesity treatment drugs produced by Lilly.

Last summer, three patients with NAION visited the clinic in a short period of time, all of whom were using semaglutide, prompting Joseph Rizzo, director of the Neuro-Ophthalmology Service at the Massachusetts Eye and Ear Infirmary and a professor at Harvard Medical School, to initiate this study.

Currently, Professor Rizzo's team is planning to collaborate with other research institutions to conduct a broader study involving more hospitals. Professor Rizzo stated: "I hope that both doctors and patients can understand this potential association. The current research results do not prove a direct causal link between drug use and eye diseases. For patients whose vision has already declined, understanding this possible risk is crucial, as it helps them make informed choices before starting treatment."