Risk of retinal vascular occlusion following COVID-19 vaccination: A meta-analysis of nearly 15 million individuals.

In 30 seconds

This systematic review and meta-analysis assessed retinal vascular occlusion after COVID-19 vaccination using five observational studies with 14,877,781 reported participants. The pooled event proportion among vaccinated individuals was 0.02% (95% CI: 0.00%-0.07%). Overall, vaccination was not significantly associated with occlusion (RR = 2.12, 95% CI: 0.65-6.90; P = .213), although separate analyses found significant associations for retinal artery and vein occlusion. Substantial heterogeneity and potential confounding limit interpretation; the findings do not establish that vaccination causes these events.

Key findings

• The pooled proportion of retinal vascular occlusion events among vaccinated individuals was 0.02% (95% CI: 0.00%-0.07%; I2 = 99.5%).
• The overall association was not statistically significant (RR = 2.12, 95% CI: 0.65-6.90; P = .213; I2 = 96.8%).
• Separate analyses found associations for retinal artery occlusion (RR = 2.03, 95% CI: 1.17-3.51) and retinal vein occlusion (RR = 2.26, 95% CI: 2.08-2.47).
• ChAdOx1/AstraZeneca was associated with occlusion (RR = 2.00, 95% CI: 1.60-2.50), based on a single study; pooled associations for other vaccines were nonsignificant.

Why it matters

The analysis quantifies the reported frequency of these uncommon events while showing that the overall association remains uncertain. Subtype findings warrant attention but should be interpreted cautiously: the evidence comes from observational studies, with substantial heterogeneity and potential confounding. Distinguishing a statistical association from a causal effect is essential when communicating vaccine safety findings.

What to keep in mind

The evidence is observational and substantially heterogeneous, with potential confounding and differences among contributing studies. The ChAdOx1/AstraZeneca association was based on a single study.