Keep Eyes on COVID-19: Ophthalmic Symptoms and Potential Transmission of SARS-CoV-2 through the Oculus

Abstract

In December 2019, a new coronavirus disease 2019 (COVID-19) emerged and rapidly spread globally, posing a worldwide health emergency. The pathogen causing this pandemic was identified as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is well known that SARS-CoV-2 transmits via respiratory droplets and close contact with infected individuals or contaminated items. In addition to these two major transmission routes, other modes of transmission have not been confirmed. Considering that some COVID-19 patients have presented with ocular discomforts and positive SARS-CoV-2 RNA in ocular surfaces, as well as the discovery of the SARS-CoV-2 receptors, angiotensin-converting enzyme 2, and transmembrane protease, serine 2, in the oculus, the ocular surface is now thought to be a possible alternative route of SARS-CoV-2 transmission and a replication site. This review summarizes the evidence connecting COVID-19 with ocular tissues, ocular symptoms during SARS-CoV-2 infection, the potential role of the conjunctiva in SARS-CoV-2 transmission, and the physiopathological mechanisms. Appropriate precautions in ophthalmology departments, including innovative complete and effective patient management plans, protective personal equipment, hand hygiene, and strict personal distance intervals, are essential to effectively minimize the spread of SARS-CoV-2 and control the pandemic.

Keywords: COVID-19; Conjunctivitis; Ocular surface; Ophthalmological infection; SARS-CoV-2.

Figure 1

The anatomical structure of the human eye and the potential circulating way of SARS-CoV-2 on the ocular surface and respiratory tract. (A) The anatomy structure of the nasolacrimal duct may facilitate the exchange of virus-containing fluid between the ocular surface and respiratory tract. (B) and (C) Show the approximate anatomical positions of the conjunctiva and cornea which are the main distribution sites of ACE2 and TMPRSS2 in the oculus that mediate the entry of SARS-CoV-2. SARS-CoV: Severe acute respiratory syndrome-associated coronavirus; ACE2: Angiotensin-converting enzyme 2; TMPRSS2: Transmembrane protease, serine 2.