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.¹ 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.² 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.³ 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.