Willcox Mark Dp, Walsh Karen, Nichols Jason J, Morgan Philip B, Jones Lyndon W
School of Optometry and Vision Science, The University of New South Wales, Sydney, New South Wales, Australia.
Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada.
Clin Exp Optom. 2020 Jul;103(4):418-424. doi: 10.1111/cxo.13088. Epub 2020 May 13.
The ocular surface has been suggested as a site of infection with Coronavirus-2 (SARS-CoV-2) responsible for the coronavirus disease-19 (COVID-19). This review examines the evidence for this hypothesis, and its implications for clinical practice. Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), responsible for the COVID-19 pandemic, is transmitted by person-to-person contact, via airborne droplets, or through contact with contaminated surfaces. SARS-CoV-2 binds to angiotensin converting enzyme-2 (ACE2) to facilitate infection in humans. This review sets out to evaluate evidence for the ocular surface as a route of infection. A literature search in this area was conducted on 15 April 2020 using the Scopus database. In total, 287 results were returned and reviewed. There is preliminary evidence for ACE2 expression on corneal and conjunctival cells, but most of the other receptors to which coronaviruses bind appear to be found under epithelia of the ocular surface. Evidence from animal studies is limited, with a single study suggesting viral particles on the eye can travel to the lung, resulting in very mild infection. Coronavirus infection is rarely associated with conjunctivitis, with occasional cases reported in patients with confirmed COVID-19, along with isolated cases of conjunctivitis as a presenting sign. Coronaviruses have been rarely isolated from tears or conjunctival swabs. The evidence suggests coronaviruses are unlikely to bind to ocular surface cells to initiate infection. Additionally, hypotheses that the virus could travel from the nasopharynx or through the conjunctival capillaries to the ocular surface during infection are probably incorrect. Conjunctivitis and isolation of the virus from the ocular surface occur only rarely, and overwhelmingly in patients with confirmed COVID-19. Necessary precautions to prevent person-to-person transmission should be employed in clinical practice throughout the pandemic, and patients should be reminded to maintain good hygiene practices.
眼表已被认为是导致冠状病毒病-19（COVID-19）的新型冠状病毒2（SARS-CoV-2）的感染部位。本综述探讨了这一假说的证据及其对临床实践的影响。导致COVID-19大流行的严重急性呼吸综合征冠状病毒2（SARS-CoV-2）通过人与人接触、空气飞沫或接触受污染表面传播。SARS-CoV-2与血管紧张素转换酶2（ACE2）结合以促进人类感染。本综述旨在评估眼表作为感染途径的证据。2020年4月15日使用Scopus数据库对该领域进行了文献检索。总共返回并审查了287条结果。有初步证据表明角膜和结膜细胞上存在ACE2表达，但冠状病毒结合的大多数其他受体似乎位于眼表上皮之下。动物研究的证据有限，一项研究表明眼睛上的病毒颗粒可传播至肺部，导致非常轻微的感染。冠状病毒感染很少与结膜炎相关，确诊COVID-19的患者偶尔有病例报告，还有孤立的结膜炎病例作为首发症状。冠状病毒很少从眼泪或结膜拭子中分离出来。证据表明冠状病毒不太可能与眼表细胞结合引发感染。此外，关于病毒在感染期间可从鼻咽部或通过结膜毛细血管传播至眼表的假说可能是错误的。结膜炎和从眼表分离出病毒的情况仅很少见，且绝大多数发生在确诊COVID-19的患者中。在整个大流行期间的临床实践中应采取必要的预防措施以防止人际传播，并且应提醒患者保持良好的卫生习惯。
