Retinal Microvascular Impairment in COVID-19 Bilateral Pneumonia Assessed by Optical Coherence Tomography Angiography

Abstract

The purpose of this study was to evaluate the presence of retinal and microvascular alterations in COVID-19 patients with bilateral pneumonia due to SARS-COV-2 that required hospital admission and compare this with a cohort of age- and sex-matched controls. COVID-19 bilateral pneumonia patients underwent retinal imaging 14 days after hospital discharge with structural optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) measurements. Vessel density (VD) and foveal avascular zone (FAZ) area were evaluated in the superficial, deep capillary plexus (SCP, DCP), and choriocapillaris (CC). After exclusion criteria, only one eye per patient was selected, and 50 eyes (25 patients and 25 controls) were included in the analysis. COVID-19 patients presented significantly thinner ganglion cell layer (GCL) (p = 0.003) and thicker retinal nerve fiber layer (RNFL) compared to controls (p = 0.048), and this RNFL thickening was greater in COVID-19 cases with cotton wool spots (CWS), when compared with patients without CWS (p = 0.032). In both SCP and DCP, COVID-19 patients presented lower VD in the foveal region (p < 0.001) and a greater FAZ area than controls (p = 0.007). These findings suggest that thrombotic and inflammatory phenomena could be happening in the retina of COVID-19 patients. Further research is warranted to analyze the longitudinal evolution of these changes over time as well as their correlation with disease severity.

Macular vessel density reduction in patients recovered from COVID-19: a longitudinal optical coherence tomography angiography study

“…In our previous cross-sectional case–control research project, we found a decrease in the macular vascular density of the recovered COVID-19 patients [ 12 ]. Other later reports also support these optical coherence tomography angiography (OCTA) findings of COVID-19 patients [ 13 – 16 ].…”

“…The findings of the present study are in line with those of the previous research performed on the retinal microvascular changes in patients with COVID-19. In recent case–control studies, using Optovue AngioVue OCTA machine, alterations of retinal microvasculature are found subsequent to COVID-19 infections, compared to healthy control groups [ 12 , 13 ]. Moreover, in a case–control study performed on patients with mild, moderate, and severe COVID-19 and normal controls, patients with moderate and severe disease had decreased macular VD on OCTA, compared to control subjects or even those who were asymptomatic or paucisymptomatic [ 16 ].…”

COVID-19-Related Retinal Micro-vasculopathy – A Review of Current Evidence

“…Among cases-control studies and case series, 18 publications (10 case-control studies [17][18][19][20][21][22][23][24][25]30 and 9 case series 13,28,29,[31][32][33][34][35][36] ) reported on the presence or absence of retinal signs related to micro-vasculopathy. Among the 10 case-control studies, retinal signs were reported in 6, with frequency ranging from 0.01% to 20%.…”

“…However, since the initial report by Marinho, several case-control studies have reported retinal features in patients with COVID-19 infection of various severity. [17][18][19][20][21][22][23][24][25] In addition to clinical features, several OCT angiography (OCTA) studies demonstrated reduction in vessel density (VD) in COVID patients, which corroborated with the possibility of COVID-19 related retinal micro-vasculopathy. [17][18][19][20][23][24][25][26] Importantly, these perfusion deficits have been detected in asymptomatic individuals with no significant medical comorbidities who have recovered from seemingly mild COVID infections.…”

“…[17][18][19][20][21][22][23][24][25] In addition to clinical features, several OCT angiography (OCTA) studies demonstrated reduction in vessel density (VD) in COVID patients, which corroborated with the possibility of COVID-19 related retinal micro-vasculopathy. [17][18][19][20][23][24][25][26] Importantly, these perfusion deficits have been detected in asymptomatic individuals with no significant medical comorbidities who have recovered from seemingly mild COVID infections. Therefore, understanding of the prevalence and progression pattern of such perfusion deficits may have significant public health implications in the long term.…”