Meta-analysisindependent cross-checkabstract checked I-ODD-119 standard review
Trials do not show a clear increase in optic nerve events with GLP-1 drugs
GLP-1 Receptor Agonists and Risk of Optic Nerve or Vision-Threatening Events in Patients With Type 2 Diabetes or Cardiometabolic Diseases: A Meta-analysis of Randomized Controlled Trials.
Overview
Li HY et al.. Diabetes Care 2026 · PMID 41587563 · DOI 10.2337/dc25-1929
ION OR 1.50 (0.49-4.63), not significant.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Pool eye safety data from GLP-1 RA trials.
- How was the study done?
Meta-analysis of 20 RCTs.
- How many people, animals or samples were studied?
83,288 participants.
- What was actually found?
No significant increase.
- How large was the observed effect?
Composite OR 1.20 (0.73-1.97).
- What do the results mean in everyday life?
If a risk exists, it is too rare to show clearly in trials.
- What are the study's limitations?
Imprecise; not prespecified.
- What does it say about Elawady's specific claim?
Does not confirm a markedly higher risk.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
That there is no risk.
Scientific in-depth review
1. Full reference
- Authors
- Li HY et al.
- Journal
- Diabetes Care
- Year
- 2026
- Identifier
- PMID 41587563 DOI 10.2337/dc25-1929
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Academic fellowships and Hong Kong Research Grants Council (PubMed record).
2. Research question
Do GLP-1 RAs increase optic nerve or vision-threatening events in RCTs?
3. Study design and population
- Study design
- Meta-analysis – Meta-analysis of RCTs
- Population
Patients with type 2 diabetes or cardiometabolic disease (76.4% with diabetes)
- Country
International
- Period
Published RCTs to 2025
- Sample size
20 RCTs, 83,288 participants; about 240,334 patient-years
- Inclusion and exclusion criteria
RCTs of GLP-1 RAs reporting optic nerve or vision adverse events
4. Methods and endpoints
- Exposure / intervention
GLP-1 RAs
- Comparator
Placebo/control
- Endpoints
Composite optic nerve/vision-threatening serious adverse events; ION; vision loss
- Statistical methods
Odds ratios; I2
5. Actual results
- Results
Composite OR 1.20 (0.73-1.97; I2 0%); ischaemic optic neuropathy OR 1.50 (0.49-4.63); vision loss/disturbance OR 1.08 (0.60-1.94).
- Absolute risks
Not reported in abstract.
- Authors' conclusion
GLP-1 RAs were not associated with an increased risk of optic nerve or vision-threatening events.
6. Strengths
- Randomised data
- Large exposure
7. Weaknesses
- Events recorded as adverse events, not prespecified
- Very wide CI for ION
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Outcome ascertainment limitation acknowledged.
9. Assessment of the statistical interpretation
ION CI 0.49-4.63 cannot exclude a doubling (stats/C-ODD-10.py); absence of significance is not evidence of absence.
10. Relevance to the specific claim
Limits the claim: randomised data do not confirm a 'markedly higher' risk, but are too imprecise to exclude a small increase.
11. Independent contrary findings
Simonsen 2025 (I-ODD-118), EMA PRAC (I-ODD-120).
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Neutral but imprecise RCT evidence.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | direct |
| Reproducibility | unknown |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Dedicated ophthalmologic assessment in trials.
15. Linked fact checks
- Semaglutide (Ozempic) is associated with a markedly higher risk of non-arteritic anterior ischaemic optic neuropathy (NAION), which can cause blindness (HR 4.28 in diabetes). – Studies contradicting or limiting the claim