Severe acute respiratory Syndrome-Coronavirus-2: Can it be detected in the retina?

Abstract

Background/Objectives The systemic organ involvement of SARS-CoV-2 needs to be thoroughly investigated including the possibility of an ocular reservoir in humans. To examine retinal tissues and vitreous for histopathology and SARS-CoV-2 presence with regard to possible effects on the human retina and/ or vitreous. We performed histopathological analyses and quantitative (q)RT-PCR-testing for SARS-CoV-2 RNA on retinal tissues and vitreous of COVID-19 postmortem donors. Subjects/Methods Included in this study were 10 eyes of 5 deceased COVID-19 patients. The diagnosis of SARS-CoV-2 infection was confirmed via pharyngeal swabs and broncho-alveolar fluids. The highest level of personal protective equipment (PPE) and measures was employed during fluid-tissue procurement and preparation. Histopathological examinations and qRT-PCR-testing were carried out for all retinal tissues and vitreous fluids. Results The histopathological examinations revealed no signs of morphologically identifiable retinal inflammation or vessel occlusions based on hematoxylin and eosin stains. By qRT-PCRs, we detected no significant level of viral RNA in human retina and vitreous. Conclusions In this study, no significant level of SARS-CoV-2-RNA was detected in the human retinal and vitreous fluid samples of deceased COVID-19 patients. Histopathological examinations confirmed no morphological sign of damage to retinal vasculature or tissues. Further studies are needed to confirm or refute the results.

Absence of detectable SARS-CoV-2 replication in ex vivo cultured cornea and cornea-derived epithelial cells

“…We previously excluded the presence of SARS-CoV-2 in various eye tissues from patients who died from COVID-19 immediately after enucleation [ 13 , 18 ]. While we did not detect SARS-CoV-2 by qRT-PCR in these tissues, there is a constant threat of a low number of infected cells possibly remaining under the limit of detection.…”

“…The potential risk of virus transmission from corneal transplantation has been addressed and discussed in several studies [ 1 , 2 , 4 , 5 , 9 , 10 , 13 , 18 ], and there is evidence available to support the potential risk of transmission, as well as evidence against it. No transmission of SARS-CoV-2 from the donor to the recipient has been documented in transplantation procedures carried out to date [ 2 ].…”

Dilemma of donor testing before corneal retrieval in the COVID-19 era

“…[ 4 9 ] Moreover, the potential source of viral material in ocular secretions is unlikely to be systemic infection as the virus does not appear to enter the bloodstream, further suggesting that direct ocular infection may be possible. [ 11 ] Recent studies reporting the presence of SARS-CoV-2 antigens in the ocular surface of deceased COVID-19 patients with evidence of cadaveric ocular surface cells getting infected on exposure to the virus reinforces this theory. [ 12 ]…”

“…[ 3 4 ] Post-mortem studies evaluating the presence of viral RNA in the ocular tissue of COVID-19-infected patients are not conclusive, with some studies reporting the presence of viral RNA in cornea, sclera, and retina and other studies reporting the absence of any viral RNA in ocular tissues. [ 5 6 7 8 9 10 11 ] The variability observed in different studies can be attributed to the extremely low prevalence of the virus in ocular tissues, the relatively small number of samples analyzed, and the lack of a validated diagnostic test for use in post-mortem settings. [ 9 11 ]…”

“…[ 5 6 7 8 9 10 11 ] The variability observed in different studies can be attributed to the extremely low prevalence of the virus in ocular tissues, the relatively small number of samples analyzed, and the lack of a validated diagnostic test for use in post-mortem settings. [ 9 11 ]…”