JUN 21, 2022
With COVID-19 known to cause vascular damage and induction of a prothrombotic state, investigators examined the risk of retinal vascular occlusions in patients with COVID-19 infections. Isolating rates of both retinal artery occlusions (RAO) and retinal vein occlusions (RVO) in the cohort from the time periods before and after infection allowed comparison and observation of any changes in risk.
This was a retrospective cohort study looking at patients in an integrated health system with history of retinal vascular occlusion who were diagnosed with COVID-19 infection between January 20, 2020, and May 31, 2021. The average biweekly incidence of new retinal vascular occlusions (RAO or RVO) was compared between the pre–COVID-19 infection period (26 to 2 weeks before diagnosis) and the post-infection period (2 weeks before to 26 weeks after diagnosis).
A total of 432,515 patients with COVID-19 infection were included in this study. The incidence of new RVOs was higher in the 6 months after COVID-19 infection compared with the 6 months before infection (adjusted IRR, 1.54). There was a smaller, non-statistically significant increase in the incidence of RAOs after COVID-19 diagnosis (IRR, 1.35). The peak incidence of RVOs occurred 6 to 8 weeks after COVID-19 diagnosis.
A cause-and-effect association could not be established in this retrospective, nonrandomized study. Certain systemic vascular risk factors (e.g., diabetes, hypertension, and hyperlipidemia) were more common in patients who had a retinal vascular occlusion. Other unaccounted-for confounders may have the changed RVO incidence coincidental to COVID-19.
There is mounting evidence of increased risk for retinal vascular occlusion associated with COVID-19 infection, likely due to a combination of vascular damage and risk of higher embolism formation. This retrospective cohort study further strengthens this presumed association—clinicians need to consider this factor when evaluating these patients.