Analysis of swept-source optical coherence tomography angiography measurement alterations in adult patients recovered from COVID-19

Background To investigate VD changes in the retinal layers and choroid using SS-OCTA in patients recovered from COVID-19. Methods This cross-sectionally designed study was conducted in a single eye centre. The diagnosis of COVID-19 disease was confirmed by a polymerase chain reaction test. Patients who had fully recovered from COVID-19 served as the COVID-19 group, and the control group comprised age- and gender-matched healthy subjects. VD measurements in the superficial and outer retina layers and the choriocapillaris were performed using SS-OCTA. Results VD measurements in the central fovea and all quadrants of superficial and deep retinal layers, and the choriocapillaris, showed a significant decrease in the COVID-19 group (P < 0.05 for all) compared to the control group. Significant reductions in VD measurements were more prominent in the choriocapillaris when compared to the retinal layers. Mean ferritin and C-reactive protein (CRP) concentrations showed negative correlations with VD measurements in certain quadrants of the deep retinal layer and choriocapillaris. Conclusion VD reductions occur the superficial and deep retinal layers and choriocapillaris in patients with pre-existing COVID-19. These results suggested the use of SS-OCTA as a microvascular biomarker and an auxiliary technique for the diagnosis and follow-up of COVID-19.