Trends in the Incidence of Retinal Artery and Vein Occlusion Before and After COVID-19: A National Study in South Korea (2017-2022).

Purpose: This study investigated the incidence of new retinal artery occlusion (RAO) and retinal vein occlusion (RVO) during the coronavirus disease-19 (COVID-19) pandemic compared to pre-outbreak periods in South Korea.

Design: Nationwide population-based retrospective cohort study PARTICIPANTS: Individuals diagnosed with RAO or RVO METHODS: We evaluated data from 326,154 patients diagnosed with RAO (n = 32,028), RVO (n = 304,405), or both (n = 10,279) from January 1, 2017 to December 31, 2022. We calculated the incidence rate ratios (IRR) of RAO and RVO using 2019 as the reference year, making comparisons across the total population and within age and sex subgroups. We examined correlations between the number of new RVO patients and COVID-19 infected or vaccinated persons. Additionally, we compared the systemic characteristics of individuals with RAO and RVO, adjusting for multiple comparisons with Bonferroni correction.

Main Outcome Measures: Annual IRRs of RAO and RVO RESULTS: The IRR for RAO showed no significant increase across all age and sex subgroups. Contrastingly, RVO exhibited a consistent IRR in 2020; however, significant increases were observed in 2021 and 2022 among those aged 20-39 years (adjusted IRR in 2021, 1.22, 95% CI, 1.15-1.29; P < 0.001; adjusted IRR in 2022, 1.12, 95% CI, 1.06-1.18; P < 0.001) as well as those aged 40-64 years (adjusted IRR in 2021, 1.11; 95% CI, 1.09-1.13; P < 0.001; adjusted IRR in 2022, 1.11, 95% CI, 1.08-1.12; P < 0.001). No correlations were found between the monthly number of patients with RVO and the number of individuals infected with or vaccinated against COVID-19. Additionally, a higher proportion of patients with RVO having hypertension, diabetes, dyslipidemia, and chronic liver disease were seen in 2021 and 2022 (Bonferroni correction, P < 0.01).

Conclusions: The incidence of RAO did not increase during the COVID-19 outbreak. However, the incidence of RVO increased during the pandemic, especially in 2021 and 2022, with the highest rates observed in the 40-64 years age group, likely linked to increases in metabolic diseases rather than COVID-19 infection and vaccination. Further research is warranted to confirm these findings.