Preprint Review Version 2 Preserved in Portico This version is not peer-reviewed

Role of the Eye in Transmitting Human Coronavirus: What We Know and What We Do Not Know

Version 1 : Received: 16 March 2020 / Approved: 17 March 2020 / Online: 17 March 2020 (09:00:38 CET)
Version 2 : Received: 23 March 2020 / Approved: 24 March 2020 / Online: 24 March 2020 (06:42:35 CET)

A peer-reviewed article of this Preprint also exists.


The outbreak of recently identified 2019 novel coronavirus (2019-nCOV) infection has become a world-wide health threat. Currently, more information is needed for further understanding the transmission, clinical characteristics, and infection control procedures of 2019-nCOV. Recently, the role of the eye in transmitting 2019-nCOV has been intensively discussed. Previous investigations about other high infectious human COVs, that is, severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), may provide helpful information. In this review, we describe the genomics and morphology of human CoVs, the epidemiology, systemic and ophthalmic manifestations, mechanisms of human CoVs infection, and infection control procedures. The role of the eye in the transmission of SARS-CoV and 2019-nCOV is discussed. Although the conjunctiva is directly exposed to extraocular pathogens, and the mucosa of ocular surface and upper respiratory tract is connected by nasolacrimal duct and share same entry receptors for some respiratory viruses. The eye is rarely involved in human CoVs infection, conjunctivitis is quite rare in patients with SARS-CoV and 2019-nCoV infection, and COV RNA positive rate by RT-PCR test in tears and conjunctival secretions from patients with SARS-CoV and 2019-nCoV infection is also very low, which imply that the eye is neither a preferred organ of human COVs infection, nor is a preferred gateway of entry for human COVs to infect respiratory tract. However, pathogens exposed to the ocular surface might be transported to nasal and nasopharyngeal mucosa by constant tear rinsing through lacrimal duct, and then cause respiratory tract infection. Considering close doctor-patient contact is quite common in ophthalmic practice which are apt to transmit human COVs by droplets and fomites, hand hygiene and personal protection are still highly recommended for health care workers to avoid hospital-related viral transmission during ophthalmic practice.


Coronavirus; 2019-nCOV; SARS-CoV-2; transmission; infection; conjunctiva; eye


Medicine and Pharmacology, Ophthalmology

Comments (1)

Comment 1
Received: 24 March 2020
Commenter: Zhe Liu
Commenter's Conflict of Interests: Author
Comment: minor modifications have been made to the 1st version of our manuscript, including some typing errors, reference arrangement mistakes, and some new supplemementary evidence.
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