Evidence of SARS-CoV-2 Transmission Through the Ocular Route

Abstract

Purpose Currently, the coronavirus disease 2019 (COVID-19) pandemic is raging around the world. However, the transmission of its pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is not fully clear. It is still controversial whether the ocular transmission of SARS-CoV-2 exists. This review aimed to summarize the evidence of SARS-CoV-2 ocular transmission. Methods Online articles were searched till October 23, 2020 in Pubmed, Embase, and websites of World Health Organization, Centers for Disease Control and Prevention COVID-19, American Academy of Ophthalmology, and American Society of Cataract and Refractive Surgery under the search strategy of ((((“COVID-19”[Mesh]) OR (“SARS-CoV-2”[Mesh])) OR (2019 novel coronavirus)) OR (2019-nCoV)) AND ((((“Conjunctivitis”[Mesh]) OR (Ocular Surface)) OR (“Eye”[Mesh])) OR (“Ophthalmology”[Mesh])). The language was not restricted. After screening, 1445 records were excluded and 168 references original articles were finally included. Results Cells of ocular surface express both the receptor of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), offering molecular bases for the ocular susceptibility to SARS-CoV-2. Accumulated COVID-19 patients presented conjunctivitis as the initial or the only symptom. Whether COVID-19 patients had ocular symptoms or not, SARS-CoV-2 was detectable on the ocular surface, and the isolated virus was infectious, proving that the ocular surface can not only be a reservoir but also a source of contagion. SARS-CoV-2 may reach the ocular surface by hand-eye contact and aerosols. Once SARS-CoV-2 reaches the ocular surface, it may transfer to other systems through the nasolacrimal system or hematogenous metastasis. Conclusion The ocular surface can serve as a reservoir and source of contagion for SARS-CoV-2. SARS-CoV-2 can be transmitted to the ocular surface through hand-eye contact and aerosols, and then transfer to other systems through nasolacrimal route and hematogenous metastasis. The possibility of ocular transmission of SARS-CoV-2 cannot be ignored.

Secret hiding places in the eye and beyond: what about after SARS-CoV-2 infection?

“…In contrast, regarding SARS-CoV-2 in the eye, Rokohl and colleagues pointed out that the virus was unambiguously detected in ocular tissues, tears, and conjunctival secretions of COVID-19 patients [ 1 ]. The key question of whether long(er)-term SARS-CoV-2 persistence in immune privileged sites such as in the eyes [ 8 ] of COVID-19 survivors or asymptomatic carriers may hold long(er)-term risks is empirically open and should be explored with targeted research [ 9 , 10 ].…”

Ocular Findings in Patients with COVID-19: Impact on Eye Banking [Letter]

“…With great interest, we have read the article by Qu et al on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through the ocular route. 1 We would like to discuss the triggered impact on eye banking and corneal transplantation.…”

“…The authors reported a high potential of SARS-CoV-2 contagion of the ocular surface through hand-eye contact and aerosols and a possible transfer to other systems via nasolacrimal route or blood metastasis. 1 No mention has been made of possible SARS-CoV-2 contagion through ocular tissue transplantation, such as corneal transplantation, which may constitute another form of “ocular route”.…”

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With great interest, we have read the article by Qu et al on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through the ocular route. 1 We would like to discuss the triggered impact on eye banking and corneal transplantation.The authors reported a high potential of SARS-CoV-2 contagion of the ocular surface through hand-eye contact and aerosols and a possible transfer to other systems via nasolacrimal route or blood metastasis. 1 No mention has been made of possible SARS-CoV-2 contagion through ocular tissue transplantation, such as corneal transplantation, which may constitute another form of "ocular route".This question, which is particularly concerning for eye banks, was already investigated by Casagrande et al They reported RNA traces in 6 out of 11 (55%) corneas of deceased donors with SARS-CoV-2 activity (viremia), or recent exposure.

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What is the risk of acquiring SARS-CoV-2 from the use of public toilets?

“…It is therefore virtually impossible to distinguish between faecal-oral and oral-oral routes of infection in a public toilet setting. In addition, unlike other viruses, SARS-CoV-2 infection may also occur via the ocular route (Qu et al, 2021), providing multiple infection points.…”