ABSTRACT
Purpose : The effects of COVID-19 on the retina have been debated since the start of the pandemic. This study aims to assess how COVID-19 may alter retinal microvasculature using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA). Methods : This prospective, cross-sectional, observational study included patients with a positive COVID-19 polymerase chain reaction (PCR) test who underwent WF SS-OCTA imaging from August 2020 to November 2021. The mean days from PCR diagnosis to imaging was 175.6. Age-matched controls included healthy eyes and fellow eyes of retinal detachment, retinal tears, retinal artery occlusion, and retinal vein occlusion. Patients with diabetes, uncontrolled hypertension, retinal disease, prior retinal surgery, and a positive COVID-19 test >365 days before imaging were excluded. Vessel density (VD) and vessel skeletonized density (VSD) were calculated (Macular Density Algorithm v0.7.3.3, ARI Network) for the superficial capillary plexus (SCP), deep capillary plexus (DCP), and whole retina using 3x3, 6x6, and 12x12 mmscans centered on the fovea. A mixed-effect multivariate multilevel linear regression model was used to identify any difference between controls and COVID-19 groups. Results : 34 eyes of 29 patients with COVID-19 and 54 eyes of 45 controls were included. Generalized reductions in VD and VSD were seen in COVID-19 eyes compared to controls (Fig 1). Controlling for age, COVID-19 was associated with a statistically significant overall reduction in VD in the SCP and whole retina in 3x3 mmand DCP of 6x6 mm scans as well as decreased VSD in the DCP in 6x6 mm scans(Table 1). Looking at changes by region, COVID-19 eyes had significant reductions in superior sectors in VD across all scan sizes and layers except the whole retina in 6x6 mm scans, and in VSD across all scan sizes and layers except the SCP in 3x3 and 6x6 mm scans and whole retina in 6x6 mm scans. Additional region-specific reductions in VD and VSD were seen in the DCP in 6x6 and 12x12 mm scans, whole retina in 12x12 mmscans, and SCP in 12x12 mmscans. Conclusions : Patients with COVID-19 showed reduced VD and VSD compared to controls. This may indicate that there are some retinal microvasculature changes in patients with prior COVID-19 infection. (Figure Presented).