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

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.