Nonarteritic Anterior Ischemic Optic Neuropathy and Semaglutide: What is This All About?

Nonarteritic anterior ischemic optic neuropathy (NAION) was first documented by a French physician Jean-Pierre Saint-Yves in 1817 (19th century). The clinical description of NAION was not known until 1935 when C. Miller Fischer thoroughly described it. Briefly, NAION is a rare (2.5-11.8 per 1,00,000 cases in men above 50 years) but serious condition that causes sudden painless loss of vision due to ischemia of the optic nerve. It is more common in Caucasians compared with Asians and is associated with various risk factors such as hypertension, type 2 diabetes (T2D), smoking, hyperlipidemia, obesity, obstructive sleep apnea, small optic nerve cup ("disk at risk"), optic nerve drusen, and certain drugs, especially phosphodiesterase type 5 inhibitors (PDE-5I), amiodarone, and cabergoline. Although the clinical development programs and real-world studies of semaglutide [a glucagon-like peptide-1 receptor agonist (GLP-1RA) approved for the treatment of T2D and obesity] did not report any significant increase in the risk of NAION, a recent retrospective cohort study suggested a possible link between NAION and semaglutide. This editorial briefly summarizes the current knowledge about NAION and its relation to metabolic disorders, cardiovascular, and antidiabetes drugs and puts a perspective concerning semaglutide.