Semaglutide didn't increase overall retinopathy risk across 23 trials, but older patients and those with long-standing diabetes showed a significant 24–28% higher risk compared to placebo.
RR 1.24 vs placeboSemaglutide was associated with a 24% increased retinopathy risk compared to placebo, though the overall risk across all comparators was not significant
What the researchers found
Across 23 randomized controlled trials involving 22,096 patients with type 2 diabetes, semaglutide was not associated with an overall increased risk of diabetic retinopathy compared to all control groups (RR 1.14, 95% CI 0.98–1.33).
However, the picture changed in subgroup analyses. Compared specifically to placebo, semaglutide was associated with a 24% increased risk of retinopathy (RR 1.24, 95% CI 1.03–1.50). Two patient groups faced the highest risk: those aged 60 or older (RR 1.27) and those with diabetes duration of 10+ years (RR 1.28). There were 730 total retinopathy cases — 463 in semaglutide groups and 267 in control groups.
Why it matters
The SUSTAIN 6 trial raised an alarm when semaglutide-treated patients developed more retinopathy complications than placebo. This meta-analysis pooling 23 trials provides the most comprehensive look at that signal. While the overall risk wasn't statistically significant, the finding that older patients and those with longer diabetes duration face elevated eye risk is clinically important — these are exactly the patients most likely to be prescribed semaglutide. It means eye monitoring should be part of semaglutide treatment planning for high-risk groups.
The numbers in context
23 RCTs · n=22,096 · 730 DR cases · overall RR 1.14 (95% CI 0.98–1.33) · vs placebo RR 1.24 (95% CI 1.03–1.50) · age ≥60 RR 1.27 · diabetes ≥10 years RR 1.28
How the study worked
Systematic review and meta-analysis of randomized controlled trials. Researchers searched electronic databases through April 2021, identified 23 RCTs reporting diabetic retinopathy events in semaglutide vs. control groups, and calculated pooled risk ratios with 95% confidence intervals using Review Manager 5.4. Subgroup analyses examined risk by comparator type, patient age, and diabetes duration.
Who was studied
Adults with type 2 diabetes mellitus across 23 randomized controlled trials
What this study cannot tell us
The overall analysis combined trials with different comparators (placebo, active drugs), which may dilute the signal. Individual trial definitions of retinopathy events may have varied. The meta-analysis relied on published trial data and could not access individual patient-level data. The mechanism behind the retinopathy signal (possibly rapid blood sugar improvement) could not be directly assessed.
How to read the evidence
Strong evidence from a meta-analysis of 23 randomized controlled trials — the gold standard of evidence synthesis. The large pooled sample (22,096 patients) provides substantial statistical power. The subgroup findings are biologically plausible and consistent with known mechanisms of rapid glycemic improvement and retinopathy.
When this study was published
Published in 2022 using data from trials through April 2021. The retinopathy question remains clinically relevant as semaglutide prescriptions continue to surge. Newer trials and real-world data since 2021 may provide additional context.
The bigger picture
As semaglutide (Ozempic, Wegovy) becomes one of the most widely prescribed drugs globally, understanding its safety profile is critical. The retinopathy signal has been one of the most debated safety concerns for GLP-1 agonists. This meta-analysis helps clarify that the risk is real but concentrated in specific patient groups — not universal. The finding aligns with the hypothesis that rapidly lowering blood sugar can temporarily worsen diabetic retinopathy, similar to what's seen when insulin is first started in poorly controlled diabetes.
Questions still open
- Is the retinopathy risk driven by semaglutide itself or by the rapid blood sugar improvement it causes?
- Should ophthalmologic screening be mandatory before starting semaglutide in patients over 60 with long-standing diabetes?
- Do other GLP-1 agonists like tirzepatide carry the same retinopathy risk in high-risk subgroups?
Common questions
Does semaglutide cause diabetic eye disease?
Should I get my eyes checked before starting semaglutide?
Read the original research
Semaglutide and Diabetic Retinopathy Risk in Patients with Type 2 Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Trials.
Clinical drug investigation, 42(1), 17-28
Citation
Wang, Feiyu; Mao, Yinjun; Wang, Hang; Liu, Yiwei; Huang, Pinfang. (2022). Semaglutide and Diabetic Retinopathy Risk in Patients with Type 2 Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Trials.. Clinical drug investigation, 42(1), 17-28. https://doi.org/10.1007/s40261-021-01110-w