Risk of Retinal Vascular Occlusion among Patients with Covid-19 and Influenza A: A Multi-Centered Analysis

ABSTRACT

Purpose of Study Severe COVID-19 infection has been associated with a hypercoagulable state, contributing to the formation of clots. Retinal vascular occlusion (RVO) is a common cause of vision impairment and is due to blockage of the retinal arteries and veins. There have been reported cases of patients with previous history of COVID-19 presenting with new RVO. Given the minimal research delving into this relationship, the purpose of this study was to investigate the short-term prevalence and risk for RVO following infection by COVID-19 compared to Influenza A. Methods Used Two cohorts were created using TrinetX, a national federated electronic health record (EHR). The two cohorts consisted of patients with a history of COVID-19 (n=2,352,475) and patients with a history of Influenza A (n=67,065). Both cohorts were balanced using 11 propensity score matching (PSM) addressing demographics and medical comorbidities. Outcomes between the two cohorts were compared using adjusted risk ratios (aRR), with a confidence interval of 95%. Summary of Results: After PSM, two cohorts of 67,063 patients each were compared. Patients in the COVID-19 cohort had an average age of 41.4+/-23.0 years compared to 34.4+/-27.7 years in the Influenza cohort. Between the two cohorts, there was no significant difference in risk of developing retinal vascular occlusion (aRR [95% CI] = 0.72 [0.49,1.06];p=0.097) and patients with COVID-19 had a significantly lower risk for developing retinal vein occlusion (aRR [95% CI] = 0.45 [0.27,0.77];p=0.03). Incidence of retinal vascular occlusion was 0.1% between both cohorts. Retinal artery occlusion was excluded from analysis due to obfuscation of the data by the EHR. Conclusion(s) Between the two cohorts, there was no significant difference in risk for developing RVO within 120 days. However, while there was no significant difference, vascular occlusions were found at a relatively younger age than the general population. Although incidence of RVO was low between the two cohorts, both viruses could be considered a risk factor for development of RVO, particularly in younger patients lacking classic risk factors for the disease.