Study identifies corneal endothelial changes following mRNA COVID-19 vaccination

A study aimed to compare corneal topographic and specular microscopic parameters both before and after patients received the Pfizer-BioNTech (BNT162b2) COVID-19 mRNA vaccine concluded that changes in corneal endothelium were seen in the short term after 2 doses.

The study looked at 128 eyes in 64 patients before and after they had received the vaccine, a time interval of nearly two and a half months (75.6 ± 4.5 days) between exams. Topographic evaluation was completed with Sirius corneal topography, and specular microscopy was completed with Tomey EM-4000 specular microscopy. Patients were also evaluated for BCVA, IOP levels, and anterior segment evaluation with biomicroscopy, as well as a dilated fundus examination.

Results showed that post-vaccine, a (542.0 (534.25–548.0)) increase in central corneal thickness was seen when compared to pre-vaccination (528.0 (520.25–537.75) (p = 0.001). Additionally, endothelial cell density (ECD) was 2597 (2550.0–2646.50) prior to vaccination and 2378.0 (2299.0–2419.0) at least 2 months after (p < 0.001).

The median mean CV value was 39.0(38.0–42.0) before vaccination measurements and 42 (40–44) after vaccination measurements (p < 0.001). Additionally, the median central corneal thickness (CCT) value was 533(526–538) prior to vaccination and 548 (543.50–556) after vaccination (p < 0.001).

Researchers concluded that the endothelium should be closely monitored in those with a low endothelial count or who have had a corneal graft.

In 2025 the US Food and Drug Administration (FDA) updated warning labels of mRNA COVID-19 vaccines to include new safety information about the risks of myocarditis and pericarditis following administration. The FDA required manufacturers of the vaccine to include both the estimated unadjusted incidence of myocarditis and/or pericarditis following administration of the 2023-2024 formula of mRNA COVID-19 vaccines, as well as the results of a study that collected information on cardiac magnetic resonance imaging (cardiac MRI) in people who developed myocarditis after receiving an mRNA COVID-19 vaccine.

References:

1. Sumer, F. and Subasi, S. (2025) ‘Evaluation of the Effects of mRNA-COVID 19 Vaccines on Corneal Endothelium’, Ophthalmic Epidemiology, 32(6), pp. 719–726. doi: 10.1080/09286586.2025.2522724. Accessed January 19, 2026.

2. FDA Approves Required Updated Warning in Labeling of mRNA COVID-19 Vaccines Regarding Myocarditis and Pericarditis Following Vaccination. Accessed January 19, 2026. https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-approves-required-updated-warning-labeling-mrna-covid-19-vaccines-regarding-myocarditis-and