COVID-19 may be transmitted through tears

Ocular manifestation appears to be rare among patients with the coronavirus disease 2019 (COVID-19), but the risk of ocular transmission should not be ruled out, a recent study has shown.

Researchers conducted a prospective case series including 43 patients (mean age, 56.6±13.7 years; 67.5 percent male) with severe COVID-19. Nasopharyngeal and tear samples were collected and subjected to the reverse transcription-polymerase chain reaction (RT-PCR) testing for SARS-CoV-2. Medical histories were accessed for documentation of ocular and systemic signs.

The most common symptom at the time of sampling was fever (95.3 percent; n=41), followed by shortness of breath (88.3 percent; n=38), and coughs (69.8 percent; n=30). Thirty patients tested positive on nasopharyngeal RT-PCR.

In comparison, only three patients received positive results from both tear and nasopharyngeal samples. The resulting rate was 7 percent.

None of the three patients whose tears tested positive for the virus needed admission into intensive care. One patient with conjunctivitis tested positive for COVID-19 through tear samples, but another who reported sensations of ocular foreign bodies tested negative.

No clear evidence of ocular transmission of COVID-19 has been reported yet, but the present study demonstrates a small but clear presence of the virus in tears. This may have happened through direct inoculation, direct migration from the respiratory tract, or by the infection of the lacrimal gland, the researchers explained.

“The possibility of disease transmission through tears should be considered even in the absence of ocular manifestations,” they added.