SARS-CoV-2 is known to be transmitted via droplets, but infected patients are unlikely to spread the virus through tears, according to a study.
“In our study, we could not find any evidence of viral shedding in tears taken at various time points over the course of disease in COVID-19-positive patients. Hence, this study suggests lower probability of disease transmission through tears,” Rupesh Agrawal, MD, a senior consultant ophthalmologist in Singapore, told Healio/OSN.
A prospective study evaluated the possibility of SARS-CoV-2 transmission through tears by assessing the presence of SARS-CoV-2 with viral isolation and quantitative reverse transcription polymerase chain reaction (RT-PCR). Patients were monitored via routine nasopharyngeal swabs, and tears were examined to understand patterns of viral shedding.
Researchers at National Center for Infectious Disease, Tan Tock Seng Hospital collected tear samples from 17 patients with COVID-19 from initial symptoms until recovery, usually by day 20. The tears were sampled using Schirmer’s test strip at varying time points between day 3 and day 20 after initial development of symptoms. None of the patients presented with ocular symptoms, but one patient developed conjunctival injection and chemosis during the hospital stay.
The virus was not detected in 64 tear samples taken during the study period, with 12, 28 and 24 samples taken during the first week, second week and third week, respectively, of initial symptoms. All tested negative for SARS-CoV-2 on viral isolation and RT-PCR. However, viral load was detected in nasal and throat swabs. Further studies are needed to establish tears as a potential source of transmission, Agrawal said. – by Robert Linnehan