Overview
- Product information for semaglutide brands has been updated after the MHRA flagged a possible risk of non‑arteritic anterior ischemic optic neuropathy that can cause sudden vision loss.
- Patients are told to seek immediate assessment at eye casualty or A&E if vision becomes suddenly blurred, clouded or rapidly worsens in one or both eyes.
- The MHRA reports three suspected UK NAION cases since semaglutide’s 2018 authorisation, noting about 10.2 million packs dispensed and characterising the risk as very rare, up to 1 in 10,000.
- Clinicians and patients are asked to report suspected vision‑related side effects through the Yellow Card scheme to support ongoing safety monitoring.
- Regulators are reviewing whether tirzepatide (Mounjaro) might share this risk, as limited case reports and a small JAMA Ophthalmology series suggest a potential association without proving causality.