GLP-1 Evidence

Not medical advice. A record of published research and our assessments of it. The limits

Semaglutide-associated risk of nonarteritic anterior ischemic optic neuropathy in patients with type 2 diabetes: A systematic review and meta-analysis of observational studies

Design
Meta-analysis · Hard outcome
Match to healthy normal-weight adults aged 55–75
Different populationDiabetes populations; absolute risk estimate is the useful quantity for any user.
Could weight loss explain it?
Unknown[Auto] Harm signal; weight-loss mediation not the relevant question, but consider whether harms relate to rapid weight loss or reduced intake.
Study tier
Study tier 3Consistent observational association with very low absolute risk; causality unproven.
Assessment
Version 2 · curated · Sep 13, 2026

Study facts come from the paper. Population match, weight-loss explanation and study tier are our judgments, made against the reference group of healthy normal-weight adults aged 55–75.

Combining five observational studies in people with type 2 diabetes, semaglutide roughly doubled the hazard of NAION, a rare cause of sudden, usually permanent vision loss, equating to about one extra case per 7,000 people treated per year. The authors note this is consistent with regulatory communications.

01Findings

What the study reported

Drugs
Semaglutide
Primary outcome
NAION in observational studies of semaglutide vs other glucose-lowering therapy in T2D
Effect
HR 2.17 (5 studies); vs SGLT2i HR 1.96; absolute risk 0.014%/year (~1 per 7,000 treated per year)
95% confidence interval
1.73 to 2.74
P value
<0.001
Follow-up
12 years
Adverse events
Not extracted
Limitations
Auto-classified from abstract only; effect estimates, adverse events and limitations not extracted. Requires manual review.

Who was studied

Age min
12
Diabetes status
type 2 diabetes

Study quality details

Study design
Meta-analysis
Sample size
not extracted
Randomization
n/a
Blinding
not stated
Comparator
not stated
Follow up duration
12 years
Outcome type
hard
Replication
5 studies consistent
Consistency with other evidence
not assessed (auto)
Population applicability
INDIRECT
Statistical precision
CI reported: 95% confidence intervals (CIs
Risk of bias
observational, registry-based; outcome misclassification possible
Funding conflicts
unclear
Peer review status
yes
02Funding

Funding and conflicts

Funding
Not stated
Industry funded
Unclear
Manufacturer
Novo Nordisk, Eli Lilly, Lilly, AstraZeneca, Sanofi, Boehringer Ingelheim
Sponsor role
not reported in abstract
Author conflicts
Several authors report honoraria from Novo Nordisk, Boehringer Ingelheim, Eli Lilly, Sanofi.
Independent replication
yes (multiple cohorts)
Notes
Authors declare relationships with the drug's manufacturer: Novo Nordisk

Funding is shown on every study and never used to score it.

03Claims

Claims this study bears on

04Source

The source, as retrieved

Abstract

[BACKGROUND] Semaglutide, a glucagon-like peptide-1 receptor agonist, is widely used for the management of type 2 diabetes (T2DM). Recent case reports have raised concerns about a potential association between semaglutide use and the development of nonarteritic anterior ischemic optic neuropathy (NAION), a rare but vision-threatening condition. We aimed to evaluate whether semaglutide use is associated with an increased risk of NAION in patients with T2DM. [METHODS AND FINDINGS] We conducted a systematic review and meta-analysis of observational studies comparing patients with T2DM aged ≥12 years treated with semaglutide to those receiving other glucose-lowering therapies. We searched PubMed, Scopus, and Web of Science databases from January 2023 to November 2025. Two reviewers independently extracted data on study design, population characteristics, and outcomes. Risk of bias was assessed using the Newcastle-Ottawa Scale, and ROBINS-I v.2. Certainty of the evidence was graded according to the GRADE framework. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using fixed-effects models; sensitivity analyses included crude and subgroup HRs, and overlapping study replacement. Leave-one-out analysis was conducted to assess small-study effects and publication bias. Results were contextualized within other meta-analyses, systematic reviews, consensus statements, and regulatory communications on the topic. Five eligible observational studies met the inclusion criteria, and 7 additional studies were included in the sensitivity analysis. Semaglutide use was associated with a significantly increased hazard of NAION compared with nonsemaglutide glucose-lowering regimens (HR 2.17, 95% CI [1.73, 2.74]; p < 0.001), regimens excluding other GLP-1 receptor agonists (HR 2.13, 95% CI [1.60, 2.83]; p < 0.001), and sodium-glucose co-transporter 2 inhibitor (SGLT2i) users (HR 1.96, 95% CI [1.28, 2.99]; p = 0.002). Despite the increased relative risk, the absolute risk remained low at 0.014% (95% CI [0.005%, 0.023%]; p = 0.002), corresponding to approximately 1 additional case of NAION per 7,000 semaglutide-treated patients annually. The results were consistent with meta-analyses of observational studies and corroborated decisions presented in regulatory communications. Due to exclusive focus on retrospective, registry-based observational studies, the evidence synthesis was limited and could be biased by study-level outcome misclassification and confounding. [CONCLUSIONS] Our findings suggest a possible association between semaglutide use and an increased risk of NAION in patients with T2DM. Although the absolute risk is low, clinicians should be aware of this potential adverse event, particularly in individuals at increased baseline risk for optic neuropathies. While these findings support current recommendations to discontinue semaglutide in patients diagnosed with NAION, the certainty of the available evidence is low, underscoring the need for further high-quality studies to clarify this association.

Where this record came from

SourceRetrievedIdentifier
pubmedSep 13, 202642166479
first ingestion