Long-Term Effect of SARS-CoV-2 Infection on the Retinal and Choroidal Microvasculature

Abstract

The purpose of this study was to evaluate the persistent changes in microvascular parameters based on optical coherence tomography angiography (OCTA) in patients hospitalized due to COVID-19 bilateral pneumonia. The case-control prospective study was carried out among 49 patients with COVID-19 and 45 healthy age- and gender-matched 2 and 8 months after hospital discharge. We found a significantly decreased vessel density (VD) in superficial capillary plexus (SCP) in COVID-19 patients. Significantly decreased vessel density (VD) in the superficial capillary plexus (SCP), the deep capillary plexus (DCP), and choriocapillaris (CC), with significantly increased vessel density observed in the choriocapillaris in the foveal area (FCC). The foveal avascular zone in DCP (FAZd) was significantly increased in the COVID-19 group. We found differences between OCTA parameters according to gender. The foveal VD in SCP and DCP was significantly decreased in women compared to men. The FAZ area in SCP (FAZs) and superior VD in the choriocapillaris (SCC) were significantly increased in women. In conclusion, we noticed persistent changes in the ocular parameters of OCTA in COVID-19 patients. At the second follow-up visit, we observed a widened FAZ zone in SCP and decreased VD in some regions of the retina and choroid.

Optical Coherence Tomography Angiography Assessment of the Optic Nerve Head in Patients Hospitalized Due to COVID-19 Bilateral Pneumonia

“…In our study, patients in the COVID-19 group did not show edema or congestion of the optic disc. This contrasts with the results of our previous study, in which a significantly thicker RNFL optic disc in the superior ( p = 0.021) and inferior ( p = 0.010) areas was present in a similar population [ 13 ]. Burgos-Blasco et al [ 9 ] suggested that neuronal cell edema secondary to neuroinflammatory injury might contribute to increased RNFL optic disc thickness.…”

“…Specifically, we found that the foveal VD of the superficial capillary plexus and the temporal VD of the deep capillary plexus were significantly reduced in women compared with men ( p = 0.008; p = 0.018, respectively). Additionally, the foveal avascular zone in the superficial capillary plexus was significantly enlarged in women ( p = 0.008) [ 13 ].…”

“…Previous research showed greater central retinal ischemia in women compared with men with SARS-CoV-2 infection [ 13 ]. Some investigators suggested that women may recover more slowly from COVID-19 than men [ 30 , 31 ].…”

“…Recent studies based on OCT findings in children recovered from COVID-19 and retinal biopsies from deceased COVID-19 patients suggested potential alterations in the RNFL and ganglion cell layer [ 2 , 9 ]. In our previous studies, we described microvascular changes in the retina and choroid assessed via OCTA in patients with COVID-19 [ 12 , 13 ].…”

Reduced Vessel Density and Enlarged Foveal Avascular Zone in the Macula as a Result of Systemic Hypoxia Caused by SARS-CoV-2 Infection

“…When patients, divided according to COVID-19 severity into mild, moderate, and severe groups, were re-examined eight months after their first ophthalmological examination, performed soon after leaving the hospital, it was found that severely infected individuals tended to exhibit a larger FAZ area but no significant differences in VD values [ 67 ]. In a study conducted by Kal et al, significantly decreased VD in the SCP was described among patients who recovered from COVID-19, and the persistence of these changes for six months was noted in the foveal area of the SCP and the superior, nasal, and inferior areas of the SCP [ 54 , 68 ]. None of the patients in this study required a stay in the intensive care unit; 26 patients of the 63 hospitalized had confirmed bilateral pneumonia by computerized tomography scans.…”