key: cord-0927013-vv2lrx2p authors: Qing, Huiling; Li, Zhijie; Yang, Zhengwei; Shi, Menghai; Huang, Zixu; Song, Jinghui; Song, Zongming title: The possibility of COVID‐19 transmission from eye to nose date: 2020-03-18 journal: Acta Ophthalmol DOI: 10.1111/aos.14412 sha: 0ac777f2217547380e42fc316940fbd325b6fd7d doc_id: 927013 cord_uid: vv2lrx2p nan T he Coronavirus Disease 2019 , caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is not only spreading throughout China but has reached more than 20 countries and has already posed threats to global health and economy. So far, the number of people infected in China has climbed to more than 70 000. Of them, at least 3019 healthcare workers have been infected. However, the specific causes of infection among healthcare workers in hospital environments are unclear. It has been confirmed that COVID-19 is mainly transmitted through both respiratory droplets and direct contact. Aerosols are another possible transmission route requiring attention. In February 2020, a report in The Lancet raised the issue that ocular surfaces may be a potential target for SARS-CoV-2 invasion (Lu et al. 2020 ). However, two recent studies do not fully support this assumption (Li et al. 2020; Zhou et al. 2020, unpublished paper) . The reason is that although a small number of COVID-19 patients have conjunctivitis, not all of them show positive test of SARS-CoV-2 nucleic acid in conjunctival sac swabs. In addition, some patients did not have conjunctivitis despite positive test results for the SARS-CoV-2 nucleic acid in their conjunctiva sac swabs (Dr. Yanping Song from Wuhan City, China, the outbreak area in China, unpublished paper). Interestingly, the medical history of the clinical physicians with COVID-19 revealed that neither of them used eye goggles when examining (physician 1) and intubating infected patients (a high-risk procedure to produce aerosol) (physician 2). Studies show that, like the severe acute respiratory syndrome coronavirus (SARS-CoV) that caused SARS, SARS-CoV-2 binds to human angiotensin-enzyme II (ACE2), using it as a cell entry receptor to invade respiratory and lung epithelium through the spike (S) protein (Zhou et al., 2020a (Zhou et al., ,2020b . However, ACE2 is mainly expressed in posterior tissues of the eye, such as the retina and the retinal pigment epithelium, not in the human conjunctival and corneal epithelium (Choudhary et al. 2017) . We presume that these previous studies ignored the characteristics of lacrimal drainage. Tears are constantly renewed by the lacrimal system. Therefore, we speculate that the virus enters the tears through droplets, which may pass through the nasolacrimal ducts and then into the respiratory tract. Combined with all this information, we assert that, when coming into contact with confirmed or suspected cases of COVID-19, healthcare workers should wear eye safety goggles. This should become one of the critical measures for preventing the spread of COVID-19. The authors hope this topic is helpful for work in the outbreak area. Therapeutic targets of renin-angiotensin system in ocular disorders 伴发 或首发病毒性结膜炎的新型冠状病毒感染 下眼科医师的防 2019-nCoV transmission through the ocular surface must not be ignored A pneumonia outbreak associated with a new coronavirus of probable bat origin Ophthalmologic evidence against the interpersonal transmission of 2019 novel coronavirus through conjunctiva. unpublished. Received on 1 Acta Ophthalmologica 2020