Purpose: The study aimed to compare corneal topographic and specular microscopic parameters before and after vaccination with activated (Pfizer -BioNTech (BNT162b2)) SARS-CoV-2 mRNA vaccine.
Methods: 128 eyes of 64 patients were evaluated in this prospective study. The time interval between pre and post-vaccination examinations was nearly two and a half months (75.6 ± 4.5 days).The topographic evaluation was made with Sirius corneal topography (Sirius, CSO Inc, Florence, Italy) and specular microscopy was made with Tomey EM-4000 specular microscopy (Tomey GmbH, Japan). All patients underwent detailed ophthalmologic examination including best-corrected visual acuity assessment (BCVA), measurement of intraocular pressure (IOP), anterior segment evaluation with biomicroscopy, and dilated fundus examination.
Results: The significant change in the topographic evaluation was the post-vaccine (542.0 (534.25-548.0)) increase in central corneal thickness compared to pre-vaccine values (528.0 (520.25-537.75) (p = 0.001). The endothelial cell density (ECD) was 2597 (2550.0-2646.50) before vaccination and 2378.0 (2299.0-2419.0) at least two months after vaccination (p < 0.001). The median mean coefficient of variation (CV) value was 39.0(38.0-42.0) before vaccination measurements and 42 (40-44) after vaccination measurements (p < 0.001). The mean hexagonality was 50.0 (48.25-52.0) before vaccination and 48(46-49) after vaccination (p < 0.001).The median central corneal thickness (CCT) value was 533(526-538) before vaccination and 548 (543.50-556) after vaccination (p < 0.001).
Conclusion: Changes in corneal endothelium occur in the short term after two-doses of the Pfizer-BioNTech (BNT162b2) COVID-19 mRNA vaccine. Hence the endothelium should be closely monitored in those with a low endothelial count or who have had a corneal graft.
Keywords: Cornea endothelial; Covid-19; specular microscopy; topography; vaccine.