Simultaneous bilateral NAION following initiation of high-dose semaglutide: a case report

We report a case of simultaneous bilateral non-arteritic anterior ischemic optic neuropathy (NAION) in a 68-year-old man with poorly controlled type 2 diabetes mellitus and significant hyperopia (+5 diopters). Visual loss began 14 days after initiating semaglutide at a relatively high dose (0.5mg/week), progressing to functional blindness within four weeks. Ophthalmologic examination revealed bilateral optic disc edema with hemorrhages, exudates, and subretinal fluid. Infectious and autoimmune causes were ruled out, and cerebrospinal fluid analysis was normal. Following the high dose of semaglutide, glycated hemoglobin decreased, although the magnitude and speed of this decline should be interpreted with caution, and the association between the drug and the optic nerve event must be considered purely temporal, with no evidence of direct causality. Despite drug discontinuation and corticosteroid treatment, visual loss persisted. The simultaneous bilateral presentation, rapid progression, and predisposing anatomical factors-crowded optic discs and possible scleral rigidity-highlight extreme vulnerability. This case illustrates a possible temporal association, representing one of the few such cases reported to date, and underscores the importance of baseline ophthalmic evaluation, close monitoring, and careful consideration of initial dosing in patients treated with GLP-1 receptor agonists.