NCT05650905

Retinal Neurovascular Coupling in Patients Previously Infected With COVID-19

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 90 (estimated)
• Sponsor: Medical University of Vienna · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

The Study objective is to measure retinal neurovascular coupling and blood flow parameters in patients previously infected with COVID-19, long COVID-19 and healthy age- and sex- matched control subjects

Detailed description

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is affecting almost all countries in the world and because of its worldwide spread has been declared as pandemic in March 2020. While respiratory symptoms are the main manifestation of acute infection, there is also increasing evidence that neurological and vascular symptoms occur, and it is unknown whether residuals remain after patients have recovered. A recent report shows that changes in the human retina are even present one month after onset of symptoms. The eye, as an extension of the brain, offers the advantage that blood vessels as well as neural tissue can be visualized non-invasively in-vivo. Neurovascular coupling is the ability of neural tissue to adapt its blood flow to its metabolic demands, a phenomenon that does not only occur in the brain, but also in the retina. In the retina, neurovascular coupling can be studied by stimulating the retina with flicker light and measuring the response of the vessels. Retinal neurovascular coupling has been found to be impaired in diseases of the central nervous system (CNS) as well as in diseases associated with endothelial dysfunction. Since COVID-19 comes with CNS manifestations as well as endothelial dysfunction, we speculate that retinal neurovascular coupling might be impaired in patients even after they have recovered from COVID-19 infection. In the current study, retinal neurovascular coupling will be measured in patients who have recovered from COVID-19 infection with and without long COVID-19 and in healthy age- and sex-matched controls with no history of COVID-19 infection. In addition, retinal oxygen saturation, vessel diameters, vessel density as well as retinal and optic nerve head blood flow will be measured. To assess structural changes, measurement of central retinal thickness as well as retinal nerve fiber layer thickness will be performed.

Conditions

• COVID-19
• Post-COVID-19 Syndrome

Interventions

Type	Name	Description
DEVICE	Dynamic Vessel Analyzer (DVA)	Retinal neurovascular coupling, Retinal vessel diameters and Retinal oxygen saturation will be assessed using the DVA
DEVICE	Fourier domain optical coherence tomography (FDOCT)	Retinal blood velocities and Retinal blood flow will be assessed using the FDOCT
DEVICE	Optical coherence tomography (OCT)	Retinal nerve fiber layer thickness, Central retinal thickness and Retinal vessel density will be assessed using the OCT
DEVICE	Laser Speckle Flowgraphy (LSFG)	Normalized blur and Relative flow volume will be assessed using the LSFG
DIAGNOSTIC_TEST	Proteomics and Metabolites in Plasma, tear fluid and finger sweat	Proteomics and Metabolites in Plasma, tear fluid and finger sweat will be assessed using a Blooddraw, filter paper and Schirmer-test

Timeline

• Start date: 2021-07-26
• Primary completion: 2025-12-31
• Completion: 2025-12-31
• First posted: 2022-12-14
• Last updated: 2025-05-16

Locations

1 site across 1 country: Austria