Evaluation of early and late COVID-19-induced vascular changes with OCTA.

OBJECTIVE: To evaluate vascular changes in the early period after coronavirus disease 2019 (COVID-19) infection and at 6-month follow-up. METHODS: This study included 50 eyes of 25 patients who had been hospitalized for polymerase chain reaction-positive COVID-19 infection and 50 eyes of 25 healthy individuals. All subjects underwent optical coherence tomography angiography using a 6 × 6 macular protocol in the early period after hospital discharge and 6 months later. Foveal vessel density (VD) and parafoveal VD values were measured from 4 quadrants (superior, inferior, nasal, and temporal) of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). The choriocapillaris (CC) flow area and the foveal avascular zone area also were measured. The OCTA measurements of the patient group were compared both between time points and with the control group at each time point. RESULTS: COVID-19 patients showed lower VD values than control subjects in all parafoveal quadrants of both the SCP (superior, p = 0.01; inferior, p = 0.048; nasal, p = 0.003; temporal, p = 0.048) and the DCP (superior, p = 0.001; inferior, p = 0.011; nasal, p = 0.012; temporal, p = 0.018) at the initial checkup and in all parafoveal quadrants of the SCP (superior, p = 0.0001; inferior, p = 0.007; nasal, p = 0.001; temporal, p = 0.017) and in 2 of the parafoveal quadrants of the DCP (superior, p = 0.003; inferior, p = 0.016) at 6-month follow-up. CC flow area values were significantly lower at the 6-month follow-up than at the initial examination (p = 0.044). CONCLUSION: It is important to perform appropriate follow-up for COVID-19 patients because retinal vascular flow changes may persist in the long term.