Retinal microvascular impairment in COVID‐19 patients: A meta‐analysis

Abstract

Background The coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has led to a global pandemic in an unprecedented time frame. Systemic vascular involvement in COVID‐19 has been identified, and SARS‐CoV‐2 has also been found to cause multiple organ ischemia and posterior ocular segment disease in mammals, raising concerns about the human retinal microvascular involvement in SARS‐CoV‐2. Objective To objectively assess the presence of retinal microvascular impairment in COVID‐19 patients by optical coherence tomography angiography (OCTA), so as to facilitate the clinical system management of COVID‐19 patients. Methods We searched PubMed, Cochrane Library, EMBASE, Ovid, CBM to collect eligible studies. The main outcomes included the vessel density (VD), area or perimeter of foveal avascular zone (FAZ), central foveal thickness (CFT), subfoveal choroidal thickness (SCT) in our meta‐analysis. Results We eventually included five studies with a total of 401 participants. Our meta‐analysis showed that nonacute infectious COVID‐19 or post‐COVID‐19 patients presented significantly lower foveal VD of deep capillary plexus (WMD = −4.22, 95% CI [−8.00, −0.43]) and thinner SCT (WMD = −10.33, 95% CI [−19.08, −1.57]) than healthy controls. The foveal VD and parafoveal VD of superficial capillary plexus, parafoveal VD of deep capillary plexus, CFT, area, and perimeter of FAZ showed no significant differences between the groups. Conclusion The patients of nonacute infectious COVID‐19 or post‐COVID‐19 displayed alterations in the retinal microvasculature and choroidal vessels, including a significantly lower foveal VD in deep capillary plexus and thinner SCT. The impairment may be a medium to long‐term process. Close ophthalmic surveillance is necessary for COVID‐19 patients or post‐COVID‐19 patients.

The central nervous system’s proteogenomic and spatial imprint upon systemic viral infections with SARS-CoV-2

“…While there is no robust evidence for a direct infection of endothelial cells by SARS-CoV-2 [94][95][96] , multiple studies suggest capillary damage in various organs 97 and functional impairment of the microvasculature has been implicated in the pathogenesis of COVID-19 acutely in the pandemic [98][99][100][101][102] . We didn't find overt signs of neurovascular damage, increased thrombosis, endothelial destruction or bleedings in our brainstem samples.…”

Alterations in the optic nerve and retina in patients with COVID-19. A theoretical review

“… 6 Several studies on the microvascular manifestations in the retina secondary to SARS-CoV-2 infection have recently been published, showing that mean macular capillary vessel density was significantly lower and with low levels of peripapillary perfusion density in patients with COVID-19 compared to age-matched normal controls, but without evidence of infection. 7 , 8 On the other hand, the scientific literature has reported central nervous system (CNS) involvement by COVID-19 infection and the neurotropic potential of SARS-CoV-2. 9 The neurological symptoms and complications in COVID-19, however, are few and inconclusive, and no long-term follow-up has been performed to date, and it has been reported that it can cause optic nerve edema.…”