Retinal Microvasculature Image Analysis Using Optical Coherence Tomography Angiography in Patients with Post-COVID-19 Syndrome

Maha Noor; Orlaith McGrath; Ines Drira; Tariq Aslam

doi:10.3390/jimaging9110234

Retinal Microvasculature Image Analysis Using Optical Coherence Tomography Angiography in Patients with Post-COVID-19 Syndrome

J Imaging. 2023 Oct 24;9(11):234. doi: 10.3390/jimaging9110234.

Authors

Maha Noor¹, Orlaith McGrath¹, Ines Drira^{1

2}, Tariq Aslam^{1

3}

Affiliations

¹ Department of Eye Research, Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Oxford Road, Manchester M13 9WL, UK.
² Ophtalmologie Département, Centre Hospitalier Universitaire de Toulouse, 31300 Toulouse, France.
³ Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.

Abstract

Several optical coherence tomography angiography (OCT-A) studies have demonstrated retinal microvascular changes in patients post-SARS-CoV-2 infection, reflecting retinal-systemic microvasculature homology. Post-COVID-19 syndrome (PCS) entails persistent symptoms following SARS-CoV-2 infection. In this study, we investigated the retinal microvasculature in PCS patients using OCT-angiography and analysed the macular retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness via spectral domain-OCT (SD-OCT). Conducted at the Manchester Royal Eye Hospital, UK, this cross-sectional study compared 40 PCS participants with 40 healthy controls, who underwent ophthalmic assessments, SD-OCT, and OCT-A imaging. OCT-A images from the superficial capillary plexus (SCP) were analysed using an in-house specialised software, OCT-A vascular image analysis (OCTAVIA), measuring the mean large vessel and capillary intensity, vessel density, ischaemia areas, and foveal avascular zone (FAZ) area and circularity. RNFL and GCL thickness was measured using the OCT machine's software. Retinal evaluations occurred at an average of 15.2 ± 6.9 months post SARS-CoV-2 infection in PCS participants. Our findings revealed no significant differences between the PCS and control groups in the OCT-A parameters or RNFL and GCL thicknesses, indicating that no long-term damage ensued in the vascular bed or retinal layers within our cohort, providing a degree of reassurance for PCS patients.

Keywords: SD-OCT; ganglion cell layer; long COVID; nerve fibre layer; optical coherence tomography angiography (OCT-A); post-COVID-19 syndrome (PCS); retina.

Grants and funding

The position of the most recent research fellow (M.N.) was funded by the University of Manchester. The position of the previous research fellow (O.M.G.) was partly funded by Canon Medical EU, Zilverstraat, The Netherlands. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.