Early on during the COVID-19 pandemic, there was great concern that tears could cause COVID-19 infections or transmit the infection between patients and family members or patients and doctors.
During the initial outbreak, the occurrence of conjunctivitis in association with COVID-19 illness was noted in China. In an article that is currently in press in JAMA Ophthalmology, 38 patients with ocular manifestation of confirmed COVID-19 patients were reviewed. This article noted the presence of significant symptoms in 12 patients with more severe systemic symptoms. Of 11 individuals who were positive for SARS-Co-V-2, which is believed to be the causative agent of COVID-19 illness, only two patients showed positive conjunctival samples. Therefore there is a risk, albeit small, of transmitting the virus through tears.
Another recent study in Ophthalmology, the journal of the American Academy of Ophthalmology showed that COVID-19 is rarely associated with conjunctivitis and that the virus was not detectable in tears. In this study, 17 COVID positive patients were repeatedly tested, and none showed viral shedding into tears. However, none of these 17 patients in the study, which was performed in Singapore, demonstrated any ocular symptoms in contrast to the China study above.
Both studies suggest that the risk of transmission via tears is small or nonexistent. A further definitive study is still required.