Retinal microvascular abnormalities in patients after COVID-19 depending on disease severity

Background: Global pandemic SARS-CoV-2 causes a prothrombotic state without fully elucidated effects. This study aims to analyse and quantify the possible retinal microvascular abnormalities.

Materials and methods: Case-control study. Patients between 18 and 55 years old with PCR-confirmed SARS-CoV-2 infection within the last 3 months were included.

Risk stratification: group 1-mild disease (asymptomatic/paucisymptomatic); group 2-moderate disease (required hospital admission with no acute respiratory distress) and group 3-severe disease (subjects who developed an acute respiratory distress were admitted in the intensive care unit and presented interleukin 6 values above 40 pg/mL). Age-matched volunteers with negative serology tests were enrolled to control group. A colour photograph, an optical coherence tomography (OCT) and an angiography using OCT centred on the fovea were performed.

Results: Control group included 27 subjects: group 1 included 24 patients, group 2 consisted of 24 patients and 21 participants were recruited for group 3. There were no funduscopic lesions, neither in the colour images nor in the structural OCT. Fovea-centred vascular density (VD) was reduced in group 2 and group 3 compared with group 1 and control group (control group vs group 2; 16.92 vs 13.37; p=0.009) (control group vs group 3; 16.92 vs .13.63; p=0.026) (group 1 vs group 2; 17.16 vs 13.37; p=0.006) (group 1 vs group 3; 17.16 vs 13.63 p=0.017).

Conclusion: Patients with moderate and severe SARS-CoV-2 pneumonia had decreased central retinal VD as compared with that of asymptomatic/paucisymptomatic cases or control subjects.