# Long-term retinal oximetry and OCT angiography in patients recovered from COVID-19

## TL;DR

This study found that even severe cases of COVID-19 do not cause lasting damage to the retinal blood vessels.

## Contribution

The study provides evidence that severe COVID-19 does not lead to chronic retinal microvascular changes.

## Key findings

- No significant differences in retinal parameters were found between groups of patients with varying disease severity.
- Severe COVID-19 patients showed no significant decrease in retinal vessel oxygen saturation 1.5 years post-recovery.
- Retinal vasculature appears resilient to long-term effects of severe COVID-19.

## Abstract

The aim of this study was to analyse retinal microvascular abnormalities in patients with various degrees of severity of the course of Coronavirus Disease 2019 (COVID-19), with a focus on patients requiring extracorporeal membrane oxygenation (ECMO) or mechanical ventilation (MV). We subclassified the patients after COVID-19 into 3 groups based on the severity of the disease and then performed standard ophthalmic examination, optical coherence tomography (OCT), macular OCT angiography (OCT-A) and retinal oximetry (RO). A total of 32 patients (21 men and 11 women; mean age of 51 years) were included in the study. Group 1 (mild COVID-19 course) included 11 patients, group 2 (moderate course) included 8 patients, and group 3 (severe course) included 13 patients which is particularly noteworthy. The median time after COVID-19 recovery was 22 months. No statistically significant difference between the groups was detected in any of the parameters of interest, suggesting resilience of retinal vasculature post-COVID-19. Patients after full recovery from severe COVID-19 do not show any significant decrease in oxygen saturation of retinal vessels 1.5 years (median) after the episode. Our data show that even a severe course of COVID-19 with ECMO or MV does not cause chronic microvascular changes in the retina.