Persistent Retinal Microvascular Impairment in COVID-19 Bilateral Pneumonia at 6-Months Follow-Up Assessed by Optical Coherence Tomography Angiography

Abstract

The purpose of this study was to evaluate the long-term evolution of retinal changes in COVID-19 patients with bilateral pneumonia. A total of 17 COVID-19 patients underwent retinal imaging 6 months after hospital discharge with structural optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). The parafoveal retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) were significantly thinner in COVID-19 patients at 6 months compared to 0 months (p = <0.001 in both cases). In the optic nerve analysis, a significantly thinner RNFL was observed (p = 0.006) but persisted significantly thickened, compared to controls (p = 0.02). The vascular density (VD) at 6 months persisted significantly decreased when compared to the control group, and no significant differences were found with the 0 months evaluation; in addition, when analyzed separately, women showed a worsening in the VD. Moreover, a significantly greater foveal area zone (FAZ) (p = 0.003) was observed in COVID-19 patients at 6 months, compared to 0 months. The cotton wool spots (CWSs) observed at baseline were no longer present at 6 months, except for one patient that developed new ones. This study demonstrates that some of the previously known microvascular alterations resulting from COVID-19, persist over time and are still evident 6 months after hospital discharge in patients who have suffered from bilateral pneumonia.

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

“…However, the authors reported the larger superficial FAZ area in COVID-19 cohort after 6 months. The difference with our results could be attributed to the older population and severe disease in the mentioned study [ 37 ]. Furthermore, the FAZ area is reported in total SCP and DCP in the present study.…”

“…In another study performed by Qin and associates [ 36 ], some neurological changes in the brain were persistent after 3 months in patients who had recovered from COVID-19 with no neurological manifestations upon the onset of the disease. In accordance with our findings, reduction of VDs in foveal SCP persisted after a 6-month follow-up in a study by Bilbao-Malave and associates [ 37 ]. However, the authors reported the larger superficial FAZ area in COVID-19 cohort after 6 months.…”

Sustained Impairment in Cardiopulmonary Exercise Capacity Testing in Patients after COVID-19: A Single Center Experience

“…Other than that, Rovas et al analyzed the vascular density, red blood cell velocity, and glycocalyx dimensions in tongue base microvessels via intravital microscopy by sidestream dark-field imaging in healthy individuals, nonventilated and ventilated COVID-19 patients [ 39 ], allowing for conclusions of graduated microvascular dysfunction with regard to COVID-19 severity. Additionally, microvascular changes in the retina were still detected in patients after bilateral SARS-CoV-2 pneumonia at 6 months [ 40 ] suggesting the possibility of persistent vascular impairment following COVID-19. Moreover, after COVID-19, persistent alterations of erythrocytes and neutrophils were most recently described [ 41 ].…”

Spectral-domain optical coherence tomography assessment of retinal and choroidal changes in patients with coronavirus disease 2019: a case-control study

“…Despite different results obtained in different studies conducted on retinal and choroidal layers and thickness based on OCT assessment, there is more consensus on reduced vascular density in the macular region, according to OCTA findings. Decreased vascular density in macula was found in multiple studies, and they have concluded that reduced vessel density of retinal capillary plexus detected in COVID-19 may result in retinal vascular complications and microvascular alterations in COVID-19 patients [ 16 – 23 ].…”