Some of the people with COVID-19 have had eye problems and signs of conjunctivitis. Can people also get infected with the novel coronavirus through their eyes? (Image: Eberhard / stock.adobe.com)
Crown transmission through the eyes?
More and more people are infected with the corona virus. According to the World Health Organization (WHO), the number of daily infections with SARS-CoV-2 in Europe crossed the 100,000 mark for the first time. According to current knowledge, the new pathogen is mainly transmitted by inhalation of droplets or aerosols. But is it also possible to get infected through the eyes?
Around 37 million infections with the SARS-CoV-2 coronavirus have now been confirmed worldwide (as of 10/10/2020). Since this is a relatively new pathogen, some scientific findings are still scarce. The virus is known to be highly infectious and is transmitted mainly by inhalation of droplets or aerosols. But can people also get infected through their eyes?
Can people also get SARS-CoV-2 through the conjunctiva or tear fluid? And to what extent could patients infected with the coronavirus infect other people through their tears? “Such routes of transmission would have a significant impact on public health and would require additional protective measures”, explains Professor Dr. Dr. med. Clemens Lange, Department of Ophthalmology of the University Medical Center of Friborg, in a communication from the German Ophthalmological Society (DOG).
Subjective visual discomfort in COVID-19
According to experts, there are isolated studies that indicate such a chain of transmission. In studies, about seven percent of patients with COVID-19 had subjective eye disorders. And signs of conjunctivitis (conjunctivitis) were seen in about one percent.
No meaningful entry or exit doors
“Some studies postulate that in these cases the virus used the eye as a gateway,” Lange explains. Tear film is also discussed as a possible medium. “If you rub your eyes with hands contaminated with COVID-19, for example, transmission to the nasal mucosa or respiratory tract would be possible,” Lange explains. Conversely, infected patients could transmit the pathogen to healthy people through their tear fluid. “If you finally take a look at the current status of the study, there is no indication that we need to view the eyes as an important entry or exit point for the virus,” Lange said.
No proven connection
So far, a link between conjunctivitis seen in studies of COVID-19 disease cannot be clearly established. “It could also be a phenomenon independent of SARSCoV-2 which occurs, for example, during intensive medical treatment or the generalized inflammatory reaction in the body of COVID19 patients”, explains the ophthalmologist. In addition, it has not yet been clearly clarified whether cells on the surface of the eye, such as those in the conjunctiva, express the SARS-CoV-2 ACE2 receptor to a clinically relevant degree and therefore are sensitive to it. ‘infection. According to the information, an ongoing study at the University ophthalmological clinic of Friborg and histological examinations of other clinics have not been able to demonstrate a significant expression of ACE2 in the conjunctiva or a link between the COVID infection. -19 and conjunctivitis.
Transmission through tear fluid?
The path of transmission via tear fluid is also rather unlikely. “The regular blinking of the eye and the small area of the eye should prevent enough virus from entering the eye,” says Lange. And there is also no clear indication of whether infected people could infect healthy people through their tears: “In patients with COVID-19, the tear film very rarely contains the RNA from the virus, ”Lange said. Therefore, infection with tear fluid should also be ruled out at this time. “Although we currently have no fear of infection by the eye, further investigation is needed to obtain information on the actual infectivity and possible locations of virus replication,” explains Prof. Dr. med. Hans Hoerauf, President of the DOG and Director of the Eye Clinic at the University Medical Center Göttingen.
Clinic staff must protect themselves
Despite the seemingly low risk, hospital staff are advised to urgently use glasses to protect the eyes from transmission of the coronavirus when providing intensive care to people with COVID19 with in or extubation. “Overall, ophthalmologic examinations of airways aerosols are likely to pose a significantly higher risk of COVID-19 infection than from the tear film and the surface of the patient’s eye,” said the DOG Lange expert. (a d)
Author and source information
This text complies with the requirements of specialized medical literature, medical directives and ongoing studies and has been verified by healthcare professionals.
German Society of Ophthalmology: Transmission of COVID-19: Aerosols are significantly more infectious than tears or conjunctiva, (accessed 10.10.2020), German Society of Ophthalmology
This article is provided for informational purposes only and should not be used for self-diagnosis or self-treatment. It cannot replace a visit to the doctor.