Abstract
Purpose :
There is compelling evidence that endothelial dysfunction and thromboembolic events are important causes of mortality and morbidity in patients with SARS-CoV-2. In the present study, we set out to investigate retinal microcirculatory and functional metabolic changes in patients after they had recovered from an acute infection.
Methods :
Twentynine Patients were recruited that had recovered from moderate to severe COVID-19 infection with no sequelae within the last 6 months before inclusion and compared to a group of 11 healthy age- and sex-matched controls. Retinal perfusion was quantified using laser speckle flowgraphy. Oxygen saturation and retinal calibers were assessed with a dynamic vessel analyzer. Arterio-venous ratio (AVR) was calculated based on retinal vessel diameter data. Blood plasma samples underwent mass spectrometry-based multi-omics profiling, including proteomics, metabolomics and eicosadomics.
Results :
Perfusion in retinal vessels was significantly lower in patients (60.6±16.0 a.u.) than in control subjects (76.2 ± 12.1 a.u., p = 0.006). Arterio-venous difference in oxygen saturation and AVR was significantly lower in patients compared to healthy controls (p = 0.021 for AVR and p = 0.023 for AV difference in oxygen saturation). Molecular profiles demonstrated down-regulation of cell adhesion molecules, NOTCH3 and fatty acids, und suggested a bisphasic dysregulation of nitric oxide synthesis after COVID-19 infection.
Conclusions :
The results of this study imply that retinal perfusion and oxygen metabolism is still significantly altered in patients well beyond the acute phase of COVID-19. This is also reflected in the molecular profiling analysis of blood plasma, indicating a down-regulation of nitric oxide-related endothelial and immunological cell functions.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.