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).
Original statement
سيماغلوتيد (أوزيمبيك) ارتبط بزيادة خطر اعتلال العصب البصري الأمامي الإقفاري غير الشرياني (NAION، اعتلال قد يسبب العمى) لدى مرضى السكري والسمنة مقارنة بالشواهد المطابقة.
verbatim according to source. Translation by the project; the Arabic wording is authoritative.
Translation
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).
Origin
- Source status
- Archive editors
- Attribution
- Archive editors (not Elawady)
- Origin
- https://eltayebat.com/rule/oral-diabetes-drugs/
- Attribution uncertainty
- Editorial narrative and study selection written by the archive operators.
- Claimed health effect
NAION (optic nerve infarction)
- Population concerned
Semaglutide users
- Geographic restriction by Elawady
none found
Scientific assessment
Potentially true – Some evidence points in favour of the statement, but it is not sufficient for a clear judgement.
Certainty of evidence: low – Further research is likely to change the assessment considerably.
1. What was claimed?
Semaglutide raises NAION risk.
2. What is demonstrably correct?
Hathaway et al.: 36-month cumulative incidence 8.9% vs 1.8%, HR 4.28 (1.62-11.29) in T2D; HR 7.64 in obesity (A-ODD-16). A 2026 Bayesian meta-analysis found RR 2.52 (95% CrI 1.56-4.72) and incidence of 118 per 100,000 semaglutide users (I-ODD-15). ADA 2026: 'monitor for NAION during eye examinations' (I-ODD-16).
3. What is wrong or exaggerated?
The first study came from a neuro-ophthalmology referral registry, where NAION patients are over-represented, producing very high incidences (8.9%) not seen in population data (A-ODD-16 vs I-ODD-15). Another 2026 meta-analysis found no consistent overall increase (pooled aHR 1.63, 0.88-2.39) and judged the evidence low to very low certainty (I-ODD-14).
4. What remains unclear?
Causality and size of risk.
5. Which studies support it?
A-ODD-16 (referral cohort HR 4.28), I-ODD-15 (meta-analysis RR 2.52), I-ODD-118 (Danish-Norwegian national cohort HR 2.81; +1.41 per 10,000 PY), I-ODD-120 (EMA PRAC 2025: very rare side effect), I-ODD-16 (ADA 2026: monitor for NAION).
6. Which studies contradict it?
I-ODD-14 (no consistent increase, aHR 1.63, 0.88-2.39), I-ODD-119 (RCT meta-analysis: ischaemic optic neuropathy OR 1.50, 0.49-4.63).
7. What applies to Germany and Europe?
EMA's safety committee reviewed NAION in 2025 (statement not fetched in this audit; verified: false).
8. What is known about Egypt?
Egypt has one of the highest diabetes prevalences in the region; the same drug classes and insulins are used. Access barriers and cost may make advice to stop medication attractive, which increases the practical risk of this claim. No Egypt-specific evidence changes the assessment.
9. What practical conclusion is appropriate?
Sudden painless vision loss on semaglutide needs urgent eye examination. A possible rare risk should be part of informed consent.
Assessment details
- Rationale for certainty of evidence
First signal from a single-centre referral cohort with few events (17 vs 6). Subsequent meta-analyses conflict: one found RR 2.52 (low-to-moderate certainty), another found no consistent increase (aHR 1.63, CI 0.88-2.39; low to very low certainty). ADA 2026 advises monitoring for NAION. Absolute risk is low (about 1 per 1,000 users in pooled data).
- Source quality
Archive editorial citing one observational study.
- Regional transferability
Universal.
- Regional scope of the claim
- general (biological/medical)
- Last reviewed
- 26 October 2026 provisional
Scientific evidence in detail
Overinterpreted – A real finding exists, but the claim draws more from it than the data allow (e.g. association taken as cause, animal data applied to humans, small effect presented as large).
Research question: Is semaglutide associated with a markedly higher risk of NAION, and how large is the absolute risk?
Research question in detail (PECO)
- Population
- People with type 2 diabetes or obesity
- Intervention or exposure
- Semaglutide
- Comparison
- Other glucose-lowering drugs (SGLT2i) or placebo
- Geographic scope
- universal biology
- Outcomes
- NAION
Study results as reported by the authors. Our assessment follows below.
What speaks for the claim?
Danish-Norwegian data: semaglutide linked to a rare optic nerve stroke
Simonsen E et al.. Diabetes Obes Metab 2025 · PMID 40098249 · DOI 10.1111/dom.16316 Cohort studyabstract checkednewly addedDanish-Norwegian national cohort vs SGLT2i users.
- Actual result
- HR 2.81 (1.67-4.75); +1.41 per 10,000 PY.
- Methodological quality
- moderate
- Relevance
- direct
- Limitations
- 32 events.
EU regulator: optic nerve stroke is a very rare semaglutide side effect
European Medicines Agency (PRAC). EMA website 2025 Guideline / position statementfull text checkednewly addedEMA PRAC: NAION is a very rare side effect of semaglutide.
- Actual result
- About two-fold risk; about 1 extra case per 10,000 person-years.
- Methodological quality
- moderate (regulatory synthesis)
- Relevance
- direct
- Limitations
- Summary statement.
What speaks against the claim?
Trials do not show a clear increase in optic nerve events with GLP-1 drugs
Li HY et al.. Diabetes Care 2026 · PMID 41587563 · DOI 10.2337/dc25-1929 Meta-analysisabstract checkednewly addedRCT meta-analysis: no significant increase.
- Actual result
- ION OR 1.50 (0.49-4.63).
- Methodological quality
- moderate (imprecise)
- Relevance
- direct
- Limitations
- Not prespecified outcomes.
Semaglutide and NAION: pooled analysis 1
Abdelaal A et al.. Ophthalmology 2026 · PMID 41692115 · DOI 10.1016/j.ophtha.2026.02.013 Meta-analysisabstract checked2026 meta-analysis found no consistent increase.
- Actual result
- aHR 1.63 (0.88-2.39); low to very low certainty.
- Methodological quality
- moderate
- Relevance
- direct
What does the overall evidence say?
Editorial assessment based on the studies above – not itself a study result.
Which position is better supported?
A real association is likely: several population studies show about a two- to three-fold relative risk, and the EMA lists NAION as a very rare side effect. The absolute risk is very low (about 1 extra case per 7,000-10,000 person-years). The HR 4.28 from a referral-centre cohort overstates the size.
Why some studies weigh more
Population-based cohorts and regulatory synthesis weigh more than a single referral-centre study; RCTs are too imprecise to decide.
Is a causal relationship established? Possible, not established EMA accepted a causal association for labelling; mechanism unknown; RCTs inconclusive.
Remaining uncertainty
Causality and mechanism.
Justified conclusion
A rare real risk is likely; 'markedly higher' is correct only in relative terms.
Why do studies seem to disagree?
Referral-centre cohort (HR 4.28) vs population cohorts (HR about 2-3) vs RCTs (not significant): selection of NAION-enriched populations inflates relative risk; RCTs are underpowered for a 1-in-10,000 event.
Does this depend on the country?
- General biological effects
- Drug pharmacology and physiology are universal.
- Eating habits
- Prolonged fasting, Ramadan fasting and very-low-carbohydrate eating change the risk of hypoglycaemia and ketoacidosis with some drugs; relevant in Egypt and among Muslims in Europe.
- Origin of the food
- Not applicable.
- Contaminants
- Not applicable.
- National production conditions
- Not applicable (same active substances; generics widely used in Egypt).
- Legal rules
- Drug labels and warnings are set by FDA/EMA and national regulators; Egyptian labelling not reviewed.
- Actual monitoring data
- No Egypt-specific pharmacovigilance data were found for this outcome.
A regional difference that changes the conclusion is not supported by robust data.
Statistical re-check
- Absolute risk translation – 1 extra case per about 7,100 person-years (CI 4,400-18,900). recalculated
- CI symmetry – HR 4.28 (1.62-11.29) symmetric; wide (SE log 0.50). recalculated
Certainty of the overall evidence (GRADE, simplified)
- Main outcome
- NAION with semaglutide
- Starting level
- low (observational studies)
- Reasons for downgrading
- inconsistency
- imprecision
- Result
- low
Simplified assessment by a single reviewer, following the GRADE approach; not a formal GRADE panel. GRADE rates the body of evidence for one outcome, not individual studies.
Clinical guidelines and official statements checked
- EMA (PRAC): PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines (2025) · Original publication
NAION is a very rare side effect of semaglutide (up to 1 in 10,000); about two-fold risk in type 2 diabetes; stop treatment if NAION is confirmed. - ADA: 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes-2026 (Diabetes Care 2026;49 Suppl 1) (2026) · Original publication
NAION reported (rare incidence); monitor for NAION during eye examinations.
Search strategy
Documented literature searches for this review (search strings in the original database syntax).
| Database | Date | Search | Looking for | Hits | Included |
|---|---|---|---|---|---|
| PubMed | 26 October 2026 | (semaglutide[tiab] OR "GLP-1 receptor agonist*"[tiab]) AND ("optic neuropathy"[tiab] OR NAION[tiab]) AND (cohort[tiab] OR "target trial"[tiab] OR meta-analysis[pt]) AND 2025:2026[dp] | both directions | 43 | |
| EMA PRAC news (June 2025) | 26 October 2026 | Fetched https://www.ema.europa.eu/en/news/prac-concludes-eye-condition-naion-very-rare-side-effect-semaglutide-medicines-ozempic-rybelsus-wegovy; full announcement read | guidelines | 1 | |
| ADA Standards of Care 2026, Section 9 (PubMed Central) | 26 October 2026 | Fetched https://pmc.ncbi.nlm.nih.gov/articles/PMC12690185/; NAION statement. The diabetesjournals.org DOI landing pages returned HTTP 403; the identical article was read in PubMed Central. | guidelines | 1 |
Open questions
Mechanism; risk with tirzepatide.
How deeply was this checked?
7 linked studies: 2 checked in full text (0 of them with a structured risk-of-bias assessment), 5 on the basis of the abstract, 0 bibliographically only. No formal assessment with two independent reviewers and no independent human expert review has taken place yet.
Last scientific review: 26 October 2026
History of the verdict
- 25 October 2026 · Phase 1 · Initial assessment: Potentially true (low)
- 26 October 2026 · Phase 4 (systematic evidence review) · Re-examined with extended evidence; verdict unchanged: Potentially true (low)
The EMA conclusion and a national cohort strengthen the existence of a rare association, but RCT evidence remains inconclusive and the claimed size is overstated; verdict kept, bottom line sharpened to state the EMA position and absolute risk.
New sources: I-ODD-118 I-ODD-119 I-ODD-120
In plain language
Some studies suggest that semaglutide may slightly increase the risk of a rare stroke of the optic nerve, which can damage sight. The first study probably overestimated the risk, and later studies disagree on whether there is a real increase. If it exists, it is roughly one case per thousand users. Sudden vision loss should be checked immediately.
Studies on this claim
Studies supporting the claim (5)
-
Semaglutide and optic nerve stroke
Hathaway JT et al.. JAMA Ophthalmol 2024 · PMID 38958939 · DOI 10.1001/jamaophthalmol.2024.2296Cohort studycited by the Tayebat archiveabstract checked★ key studyIn an eye-clinic registry, semaglutide users had about 4 times more NAION, but numbers were small.
Does the study support the specific claim? Partly · Methodological quality: low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Semaglutide and NAION risk
- How was the study done?
Retrospective matched cohort from a neuro-ophthalmology registry
- How many people, animals or samples were studied?
16,827 screened; 710 T2D, 979 overweight/obese; Patients evaluated by neuro-ophthalmologists at one academic institution
- What was actually found?
HR 4.28 (T2D).
- How large was the observed effect?
HR 4.28 (1.62-11.29)
- What do the results mean in everyday life?
Possible rare eye risk.
- What are the study's limitations?
Referral population (selection bias); Few events; Single centre
- What does it say about Elawady's specific claim?
Supports C-ODD-10.
- Do the results apply to Germany and Europe?
US data.
- What can explicitly not be concluded from this study?
Causation or population incidence.
-
Semaglutide and NAION: pooled analysis 2
Dhivagaran T et al.. Neurology 2026 · PMID 42060879 · DOI 10.1212/WNL.0000000000214864Meta-analysisindependent cross-checkabstract checkedRisk about 2.5 times higher, but absolute risk about 1 per 1,000 users.
Does the study support the specific claim? Yes · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
GLP-1 RA use and NAION risk
- How was the study done?
Systematic review and Bayesian meta-analysis (ROBINS-I, GRADE)
- How many people, animals or samples were studied?
5 studies; 1,593,554 patients; GLP-1 RA users vs non-users
- What was actually found?
RR 2.52.
- How large was the observed effect?
RR 2.52 (1.56-4.72)
- What do the results mean in everyday life?
Possible rare eye risk.
- What are the study's limitations?
Observational inputs; Heterogeneous incidence
- What does it say about Elawady's specific claim?
Supports C-ODD-10.
- Do the results apply to Germany and Europe?
Multinational.
- What can explicitly not be concluded from this study?
Causation definitively.
-
ADA guideline 2026: diabetes medicines
American Diabetes Association Professional Practice Committee for Diabetes*. Diabetes Care 2026 · PMID 41358900 · DOI 10.2337/dc26-S009Guideline / position statementindependent cross-checkfull text checked★ key studyInsulin is essential in type 1 diabetes; SGLT2/GLP-1 drugs are recommended for heart and kidney protection; side effects listed.
Does the study support the specific claim? Partly · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Pharmacologic glycaemic treatment
- How was the study done?
Clinical practice guideline (ADA Standards of Care 2026, Section 9)
- How many people, animals or samples were studied?
not applicable; People with type 1 and type 2 diabetes
- What was actually found?
See results.
- How large was the observed effect?
not applicable
- What do the results mean in everyday life?
Medicines chosen by benefit-risk.
- What are the study's limitations?
Partially read
- What does it say about Elawady's specific claim?
Contradicts C-INS-07, C-INS-10, C-ODD-06; supports C-ODD-07, C-INS-11.
- Do the results apply to Germany and Europe?
Consistent with ADA/EASD consensus.
- What can explicitly not be concluded from this study?
Not applicable.
-
Danish-Norwegian data: semaglutide linked to a rare optic nerve stroke
Simonsen E et al.. Diabetes Obes Metab 2025 · PMID 40098249 · DOI 10.1111/dom.16316Cohort studyindependent cross-checkabstract checked★ key studyHR 2.81, but only about 1 extra case per 7,000 patient-years.
HR 2.81; absolute +1.41 per 10,000 person-years.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Test semaglutide-NAION association in national data.
- How was the study done?
Register cohort vs SGLT2i users.
- How many people, animals or samples were studied?
61,377 semaglutide users.
- What was actually found?
About 3-fold relative risk; very low absolute risk.
- How large was the observed effect?
HR 2.81 (1.67-4.75); IRD +1.41/10,000 PY.
- What do the results mean in everyday life?
A real but very rare risk; sudden vision loss needs urgent care.
- What are the study's limitations?
32 events.
- What does it say about Elawady's specific claim?
Supports the association, not the 'markedly higher' size from the referral study.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Causality.
-
EU regulator: optic nerve stroke is a very rare semaglutide side effect
European Medicines Agency (PRAC). EMA website 2025Guideline / position statementindependent cross-checkfull text checked★ key studyAbout 1 extra case per 10,000 person-years; product information updated.
EMA classifies NAION as a very rare side effect (about 1 per 10,000 person-years).
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Assess NAION with semaglutide.
- How was the study done?
Regulatory review of all data.
- How many people, animals or samples were studied?
Not applicable.
- What was actually found?
Very rare side effect, about two-fold relative risk.
- How large was the observed effect?
About +1 per 10,000 person-years.
- What do the results mean in everyday life?
Seek urgent care for sudden vision loss; the risk is very low.
- What are the study's limitations?
Summary statement.
- What does it say about Elawady's specific claim?
Supports a real association with very low absolute risk.
- Do the results apply to Germany and Europe?
Direct.
- What can explicitly not be concluded from this study?
Mechanism.
No study in this group is marked as key.
Studies contradicting or limiting the claim (2)
-
Semaglutide and NAION: pooled analysis 1
Abdelaal A et al.. Ophthalmology 2026 · PMID 41692115 · DOI 10.1016/j.ophtha.2026.02.013Meta-analysisindependent cross-checkabstract checkedNo consistent overall increase found; possible increase in diabetes patients; evidence weak.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Semaglutide vs non-GLP-1 RA therapy and NAION
- How was the study done?
Systematic review and meta-analysis of observational studies with GRADE
- How many people, animals or samples were studied?
6 studies; 4,831,654 participants; Adults on semaglutide or comparators
- What was actually found?
aHR 1.63 (n.s.).
- How large was the observed effect?
aHR 1.63 (0.88-2.39)
- What do the results mean in everyday life?
Risk uncertain.
- What are the study's limitations?
Observational inputs; Extreme heterogeneity
- What does it say about Elawady's specific claim?
Limits C-ODD-10.
- Do the results apply to Germany and Europe?
Includes multinational data.
- What can explicitly not be concluded from this study?
Causation.
-
Trials do not show a clear increase in optic nerve events with GLP-1 drugs
Li HY et al.. Diabetes Care 2026 · PMID 41587563 · DOI 10.2337/dc25-1929Meta-analysisindependent cross-checkabstract checkedION OR 1.50 (0.49-4.63), not significant.
ION OR 1.50 (0.49-4.63), not significant.
Does the study support the specific claim? No · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
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.
No study in this group is marked as key.
Studies with mixed or unclear results (0)
No studies in this group.
Regional context
Germany / EU
EMA's safety committee reviewed NAION in 2025 (statement not fetched in this audit; verified: false).
Egypt
Egypt has one of the highest diabetes prevalences in the region; the same drug classes and insulins are used. Access barriers and cost may make advice to stop medication attractive, which increases the practical risk of this claim. No Egypt-specific evidence changes the assessment.
What applies in my country?
General scientific assessment
Potentially true Possibly true: semaglutide is probably linked to a rare optic-nerve stroke (EMA: very rare side effect, about 1 extra case per 10,000 person-years), but the HR 4.28 from a referral clinic overstates the risk and trials have not confirmed it.
This statement concerns biological or medical relationships. The scientific assessment above applies regardless of the country; country-specific food data do not change it.
References
- Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide.. Hathaway JT et al.. JAMA Ophthalmol 2024 · PMID 38958939 · DOI 10.1001/jamaophthalmol.2024.2296
- Glucagon-like Peptide-1 Receptor Agonists and Risk of Nonarteritic Anterior Ischemic Optic Neuropathy: Systematic Review and Meta-Analysis.. Dhivagaran T et al.. Neurology 2026 · PMID 42060879 · DOI 10.1212/WNL.0000000000214864
- 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes-2026.. American Diabetes Association Professional Practice Committee for Diabetes*. Diabetes Care 2026 · PMID 41358900 · DOI 10.2337/dc26-S009
- Use of semaglutide and risk of non-arteritic anterior ischemic optic neuropathy: A Danish-Norwegian cohort study.. Simonsen E et al.. Diabetes Obes Metab 2025 · PMID 40098249 · DOI 10.1111/dom.16316
- PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines Ozempic, Rybelsus and Wegovy (EMA news, 6 June 2025). European Medicines Agency (PRAC). EMA website 2025
- Semaglutide and the Risk of Nonarteritic Ischemic Optic Neuropathy: A Systematic Review and Certainty of Evidence Meta-Analysis.. Abdelaal A et al.. Ophthalmology 2026 · PMID 41692115 · DOI 10.1016/j.ophtha.2026.02.013
- 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.. Li HY et al.. Diabetes Care 2026 · PMID 41587563 · DOI 10.2337/dc25-1929