Potential of Ocular Transmission of SARS-CoV-2: A Review

• Main Authors: Brad P. Barnett, Karl Wahlin, Michal Krawczyk, Doran Spencer, Derek Welsbie, Natalie Afshari, Daniel Chao
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Vision
• Subjects: SARS-CoV-2; COVID-19; ocular transmission; conjunctivitis; coronavirus
• Online Access: https://www.mdpi.com/2411-5150/4/3/40

Purpose of review: to provide a prospective on the current mechanisms by which SARS-CoV-2 enters cells and replicates, and its implications for ocular transmission. The literature was analyzed to understand ocular transmission as well as molecular mechanisms by which SARS-CoV-2 enters cells and replicates. Analysis of gene expression profiles from available datasets, published immunohistochemistry, as well as current literature was reviewed, to assess the likelihood that ocular inoculation of SARS-CoV-2 results in systemic infection. Recent findings: The ocular surface and retina have the necessary proteins, Transmembrane Serine Protease 2 (TMPRSS2), CD147, Angiotensin-Converting Enzyme 2 (ACE2) and Cathepsin L (CTSL) necessary to be infected with SARS-CoV-2. In addition to direct ocular infection, virus carried by tears through the nasolacrimal duct to nasal epithelium represent a means of ocular inoculation. Summary: There is evidence that SARS-CoV-2 may either directly infect cells on the ocular surface, or virus can be carried by tears through the nasolacrimal duct to infect the nasal or gastrointestinal epithelium.