Dry Eye Syndrome in Children during the COVID-19 Pandemic

The aim of this study was to investigate the occurrence of dry eye syndrome (DES) in children under 18 years old before and during the COVID-19 pandemic using nationwide population-based cohort analysis. This study utilized the database provided by the Korea Disease Control and Prevention Agency and the Korean National Health Insurance Service. We used claims-based data for patients diagnosed with COVID-19 between October 8, 2020, and December 31, 2021, and those without a diagnosis of COVID-19. DES cases were defined as having at least one diagnosis of H0411 or H1621 based on the International Classification of Diseases, 10th Revision codes. The primary outcome was the evaluation of the hazard ratio for DES between the COVID-19 season and the non-COVID-19 season. A total of 198,486 individuals from the COVID-19 season cohort and 211,828 individuals from the non-COVID-19 season cohort were included in the study. There were no differences in characteristics between the COVID-19 season cohort and the non-COVID-19 season cohort (all standardized mean difference,