# Relationship Between COVID‐19 and Retinal Artery Occlusions

## TL;DR

This paper explores whether COVID-19 infection or vaccination is linked to retinal artery occlusions, finding some evidence but no definitive conclusion.

## Contribution

The study provides a review of case reports and data on retinal artery occlusions following COVID-19 infection or vaccination, highlighting the need for further research.

## Key findings

- The average age of retinal artery occlusion occurrence was lower after vaccination compared to infection.
- Initial and final visual acuity varied between central and branch retinal artery occlusions following infection or vaccination.
- Current evidence does not confirm a clear relationship between COVID-19 or its vaccine and retinal artery occlusions.

## Abstract

The relationship between coronavirus disease 2019 (COVID‐19) infection or vaccination and retinal artery occlusions (RAOs) remains controversial. COVID‐19 infection or vaccination can sometimes cause thrombin formation. RAOs occur due to thrombin in the retinal artery. The average age of occurrence after COVID‐19 infection was 48.7 ± 17.2 years in central RAO (CRAO) and 41.3 ± 17.8 years in branch RAO (BRAO). After COVID‐19 vaccination, the average age was 54.7 ± 17.1 years in CRAO and 62.3 ± 21.2 years in BRAO. The mean time from COVID‐19 diagnosis to symptom onset was 10.5 ± 9.3 days in CRAO and 48.3 ± 39.6 days in BRAO. After vaccination, the mean time was 7.3 ± 6.8 days in CRAO and 21.0 ± 24.9 days in BRAO. Initial visual acuity (VA) after COVID‐19 infection was 2.53 ± 0.65 in CRAO and 0.09 ± 0.07 in BRAO. Final VA was 2.73 ± 0.12 in CRAO, but data for BRAO were unavailable. After vaccination, initial VA was 2.28 ± 0.97 in CRAO and −0.02 ± 0.16 in BRAO. Final VA was 2.12 ± 1.24 in CRAO and could not be calculated in BRAO. The relationship between COVID‐19 or its vaccination and RAOs was investigated through past case reports. Two types of reports existed regarding RAO incidence after the COVID‐19 pandemic—some indicated an increase, while others found no change. No reports suggested a decrease in RAO occurrence. The current evidence does not clarify the relationship between COVID‐19 or its vaccine and RAOs. However, this relationship cannot be ruled out. Further investigations are necessary, as future infectious disease pandemics may occur.