Optical coherence tomography angiography analysis of the retina in patients recovered from COVID-19: a case-control study

Objective: To quantify the density of the macular microvasculature and the area of the foveal avascular zone (FAZ) in patients recovered from coronavirus disease 2019 (COVID-19) using optical coherence tomography angiography (OCTA) analysis. Methods: In a comparative cross-sectional, observational study, patients recovered from COVID-19 were included in this study. All included subjects exhibited a reverse transcription-polymerase chain reaction-confirmed diagnosis of COVID-19. Spectral domain macular OCTA was performed at least 2 weeks after recovery from systemic COVID-19. Vessel density (VD) of the superficial (SCP) and deep retinal capillary plexus (DCP) and the area of the FAZ were measured in COVID-19 recovered patients versus age-matched normal controls. Results: Thirty-one recovered COVID-19 patients and 23 healthy normal controls were studied. Mean quality scan index was 7.64 +/- 0.66 in the COVID cases and 8.34 +/- 0.71 in the normal controls (p = 0.001). Mean SCP VD and DCP VD of the COVID cohort were significantly lower than the SCP VD and DCP VD of the control group in the foveal and parafoveal regions. FAZ area was greater in the COVID cohort, but this difference was not statistically significant. In addition, in the COVID cohort, VD of the SCP was lower in patients with a history of COVID-19 hospitalization versus those without such a history, but this did not reach statistical significance. Conclusions: Patients recovered from COVID-19 displayed alterations in the retinal microvasculature, including a significantly lower VD in the SCP and DCP. Patients with coronavirus infection may be at risk of retinal vascular complications.