• Recent findings indicate a significant association between GLP-1 medications and an increased incidence of neovascular or “wet” age-related macular degeneration among individuals with type 2 diabetes.

  • The duration of GLP-1 medication usage, especially those formulations that include semaglutide, correlates with a heightened risk of developing this eye condition.

  • Despite their growing popularity for weight management, the implications of GLP-1 drugs like Ozempic and Wegovy on ocular health remain largely unexplored, warn eye specialists.

Studies have linked GLP-1 medications to a substantially increased risk of developing “wet” age-related macular degeneration (AMD).

A team from the University of Toronto discovered that individuals with type 2 diabetes on GLP-1 therapies are more than twice as likely to develop wet AMD compared to non-users. Furthermore, the risk escalates with the duration of drug use.

Wet AMD, a severe and less common form of age-related macular degeneration, is a primary cause of permanent vision loss in older adults across the U.S.

The study results, which were released on June 5 in JAMA Ophthalmology, highlight the need for heightened awareness among healthcare providers and patients about the potential ocular risks associated with these drugs, despite the overall low probability of developing this condition.

GLP-1 medications, which include well-known brands like Ozempic and Wegovy, have gained significant traction as treatments for diabetes and obesity due to their notable benefits such as weight loss, improved glucose levels, and lower risk of heart disease.

However, the impact of GLP-1 medications on eye health is not thoroughly understood, according to eye care professionals. Research has shown a correlation between these drugs and various other eye issues, including diabetic retinopathy and non-arteritic anterior ischemic optic neuropathy (NAION).

While the data does not definitively prove a direct cause-effect relationship between GLP-1 medications and eye disease, the evidence suggests caution is advisable.

Andrew Mihalache, MD(C), from the Temerty Faculty of Medicine at the University of Toronto, noted, “The dose-response relationship we observed suggests a potential biological effect rather than just a coincidence. This warrants further investigation to establish a clear link.”

Extended Use of GLP-1 Medications Linked to Increased Risk of Wet AMD

Utilizing health record data from Ontario, Canada, the University of Toronto’s research team analyzed data from nearly 140,000 adults with type 2 diabetes to explore the connection between GLP-1 usage and wet AMD over a three-year period ending in 2023.

About 46,000 of these individuals, or roughly one-third, had been prescribed a GLP-1 medication for at least six months, predominantly semaglutide. The average age of participants was 66, with a nearly equal distribution of males and females.

The findings showed that participants on GLP-1 drugs had over double the chances of being diagnosed with wet AMD compared to those not on these medications. Moreover, the risk increased progressively with longer medication use.

Interestingly, patients who had used GLP-1 drugs for 6–18 months had a slightly lower risk than those who never used these drugs. However, after 18–30 months of use, the risk more than doubled, and after 30 months, it more than tripled compared to non-users.

Reut Shor, MD, from the University of Toronto’s Department of Ophthalmology and Vision Sciences, emphasized the unexpected nature of these findings given the positive metabolic and cardiovascular benefits associated with GLP-1 receptor agonists. This underscores the necessity for further research into their effects on eye health.

Despite the observed increase in risk, the actual likelihood of developing wet AMD was still relatively low, affecting 0.2% of those on GLP-1 drugs versus 0.1% of non-users.

Potential Ocular Risks of GLP-1 Medications

The recent study adds to the growing body of evidence concerning the potential ocular risks posed by GLP-1 medications.

Earlier studies, including a significant phase 3 trial of semaglutide in 2016, have shown an increased risk of diabetic retinopathy complications in patients taking this drug, according to findings published in The New England Journal of Medicine.

However, subsequent studies have shown mixed results. A 2024 retrospective study involving nearly 700 subjects found no link between GLP-1s and worsening retinopathy, while another 2024 study indicated a higher risk of NAION among patients prescribed semaglutide.

The exact mechanism by which GLP-1 drugs might contribute to wet AMD is not fully understood, but it is believed that rapid blood sugar reduction can cause reduced oxygen levels in the retina, promoting abnormal blood vessel growth.

Linda Lam, MD, MBA, an ophthalmologist at Keck Medicine of USC, noted that these drugs could exacerbate conditions leading to wet AMD, particularly in older patients with diabetes. She stressed the importance of regular eye exams to catch and treat eye diseases early.

For those with type 2 diabetes, especially those on GLP-1 medications, being vigilant about signs of vision loss is crucial. Symptoms to watch for include:

  • blurred or distorted central vision
  • objects appearing wavy or curved
  • the emergence of new blind spots
  • trouble with reading or driving
  • difficulty recognizing faces