Do GLP-1 Medications Like Semaglutide Increase Risk of a Rare Eye Condition? | Research

The takeaway

GLP-1 receptor agonists were associated with a small but statistically significant increased risk of nonarteritic anterior ischemic optic neuropathy (NAION) over five years in type 2 diabetes patients.

1.34× risk ratio
GLP-1 users had 34% higher relative risk of NAION vs. matched controls, but only 0.022% absolute increase

What the researchers found

Type 2 diabetes patients on GLP-1 receptor agonists had a statistically significant 33.9% higher relative risk of NAION over five years (risk ratio 1.339, 95% CI 1.137-1.577, p=0.005), though the absolute risk difference was only 0.022%.

Why it matters

With millions of people now taking GLP-1 receptor agonists for diabetes and obesity, even rare adverse effects need to be understood so clinicians can monitor patients appropriately and counsel them about potential risks.

How the study worked

Retrospective cohort analysis using the TriNetX Global Collaborative Network with propensity-score matching across 20 covariates, yielding 388,333 patients per cohort.

What this study cannot tell us

Retrospective design limits causal inference. The absolute risk increase is very small and may not be clinically meaningful. The exact mechanism linking GLP-1 therapy to NAION remains unknown. Confounders beyond the 20 matched covariates could contribute.

How to read the evidence

Large retrospective cohort study with propensity-score matching and sensitivity analysis, but limited by observational design and inability to establish causation.

When this study was published

Published in 2025, reflecting current pharmacovigilance data on GLP-1 receptor agonists.

The bigger picture

As GLP-1 receptor agonists become some of the most widely prescribed medications globally, understanding their full safety profile—including rare complications—is essential. This study adds to mixed evidence about ocular risks and highlights the need for prospective research.

Questions still open

What biological mechanism could explain the association between GLP-1 receptor agonists and optic nerve ischemia?
Does the risk vary between different GLP-1 medications (semaglutide vs. liraglutide vs. others)?
Should patients on GLP-1 therapy receive routine ophthalmologic screening for early signs of optic neuropathy?

Common questions

What is NAION and why is it concerning?

NAION (nonarteritic anterior ischemic optic neuropathy) is one of the most common causes of sudden vision loss in adults. It occurs when blood flow to the optic nerve is disrupted, and there is currently no proven treatment.

Should I stop taking my GLP-1 medication because of this study?

No. The absolute risk increase is extremely small (0.022%), and GLP-1 medications have well-established benefits for diabetes and cardiovascular health. The authors emphasize the strong benefit-to-risk ratio. Discuss any concerns with your doctor.

Read the original research

Sight Unseen: Glucagon-Like Peptide-1 (GLP-1) Agonism Therapy and Nonarteritic Anterior Ischemic Optic Neuropathy.

Cureus, 18(1), e100953

View on PubMed ↗Publisher’s paper ↗

Citation

Barnett, Maxim J; Ibe, Festus; Lam, Justin. (2026). Sight Unseen: Glucagon-Like Peptide-1 (GLP-1) Agonism Therapy and Nonarteritic Anterior Ischemic Optic Neuropathy.. Cureus, 18(1), e100953. https://doi.org/10.7759/cureus.100953