A 47-year-old healthy woman developed progressive non-arteritic anterior ischemic optic neuropathy (NAION) after starting liraglutide for weight loss, with vision deteriorating to 20/400 after switching to semaglutide.
Vision declined to 20/400A previously healthy patient's vision deteriorated from 20/40 to near-blindness over months while taking liraglutide and then semaglutide for weight loss
What the researchers found
A 47-year-old Caucasian female (BMI 27.92) with no systemic risk factors developed progressive NAION one month after initiating liraglutide therapy for weight loss. Initial presentation showed BCVA of 20/40 with optic nerve head swelling and inferior visual field defects. Despite oral corticosteroid treatment (discontinued due to poor glycemic control), the condition progressed.
After three months, she was switched to semaglutide due to poor weight loss results. Eight months later, vision had deteriorated to 20/400 with persistent ONH edema confirmed on OCT and worsened visual field defects. Given the absence of any anatomical or systemic risk factors, NAION was attributed to GLP-1 receptor agonist therapy, with liraglutide as the likely initial trigger and semaglutide as a contributing factor in progression.
Why it matters
As GLP-1 receptor agonists become the most widely prescribed medications for weight loss — often in relatively healthy patients with modest obesity — rare but serious adverse effects become critically important. NAION causes permanent vision loss, and this case occurred in a patient without any of the traditional risk factors (diabetes, hypertension, cardiovascular disease). The close temporal correlation and absence of alternative explanations raise an important safety signal for the millions of people using these peptide drugs.
How the study worked
This is a clinical case report of a single patient. The diagnostic workup included best-corrected visual acuity testing, optic nerve head examination, Humphrey Visual Field testing, and optical coherence tomography (OCT) at multiple time points. The temporal relationship between drug initiation and symptom onset, combined with the absence of typical NAION risk factors, formed the basis for the causation assessment.
What this study cannot tell us
This is a single case report, which is the lowest level of clinical evidence and cannot establish causation. NAION can occur spontaneously, and the temporal association with GLP-1 therapy may be coincidental. The patient's optic disc anatomy (disc-at-risk phenotype) was not specifically assessed, which is a major predisposing factor for NAION. Without a control group or large-scale epidemiological data, the true risk attributable to GLP-1 agonists remains uncertain.
How to read the evidence
This is a single case report — the lowest tier of clinical evidence. While it provides a detailed temporal narrative and thorough exclusion of alternative causes, it cannot prove causation. Case reports are important for generating safety signals but require epidemiological confirmation through larger studies.
When this study was published
Published in 2025, this is a very recent case report contributing to the ongoing safety assessment of GLP-1 receptor agonists in the weight loss population.
The bigger picture
This case report adds to a growing body of pharmacovigilance signals linking GLP-1 receptor agonists to non-arteritic anterior ischemic optic neuropathy. A 2024 retrospective study found a significantly elevated NAION risk with semaglutide, though causality remains debated. As these peptide drugs expand from diabetic to non-diabetic populations for weight management, monitoring for rare but severe ocular complications becomes increasingly important — especially in younger, healthier patients who have fewer competing risk factors.
Questions still open
- Is there a specific mechanism by which GLP-1 receptor agonists could cause optic nerve ischemia, or is this mediated through rapid metabolic changes?
- Should patients starting GLP-1 agonists undergo baseline ophthalmic screening, particularly for 'disc-at-risk' anatomy?
- Does the risk of NAION differ between liraglutide, semaglutide, and newer GLP-1 drugs like tirzepatide?
Common questions
What is NAION and why is it serious?
Should people taking semaglutide or liraglutide for weight loss worry about their vision?
Read the original research
Non-Arteritic Anterior Ischemic Optic Neuropathy in an Otherwise Healthy Young Adult Patient Treated with Liraglutide and Semaglutide for Weight Loss: A Cautionary Tale.
International medical case reports journal, 18, 991-995
Citation
Lixi, Filippo; Calabresi, Valerio; Cukurova, Feyza; Giannaccare, Giuseppe. (2025). Non-Arteritic Anterior Ischemic Optic Neuropathy in an Otherwise Healthy Young Adult Patient Treated with Liraglutide and Semaglutide for Weight Loss: A Cautionary Tale.. International medical case reports journal, 18, 991-995. https://doi.org/10.2147/IMCRJ.S531930