In a bizarre incident, five patients have tested positive for COVID-19 through their tear sample. However, of five patients, only one showed ocular signs of disease.
According to a study that highlighted this case, COVID-19 may be transmitted through ocular routes. Consequently, this highlights the importance of taking precautions during ocular examinations of patients diagnosed with COVID-19.
“It is worth noting that the viral load in conjunctival samples is generally lower when compared to nasopharyngeal secretions,” Dr. Kanishk Singh from All India Institute of Medical Sciences, and colleagues wrote in Cureus journal. “Despite this disparity, concerns persist regarding the potential transmission of the disease through tear samples, even when obvious ocular signs and symptoms are absent.”
A team of researchers conducted a cross-sectional study at the All India Institute of Medical Sciences, Nagpur, India from February to June 2021 and included 40 patients who tested positive for COVID-19, based on nasopharyngeal, real-time reverse transcription-polymerase chain reaction (RT-PCR) assay.
Along with conducting a full ocular examination, the team of scientists collected tear samples within 48 hours of collecting naso-oropharyngeal samples. They submitted the samples for analysis via RT-PCR.
The researchers found 65 percent of participants had moderate COVID-19, 15 percent had severe COVID-19 and the rest had mild COVID-19. Five patients tested positive for COVID-19 in their tear samples, but only one had eye-related of the disease.
Moreover, out of the seven patients who had ocular signs like dry eye symptoms, conjunctivitis and lid edema, only one tested positive for COVID-19 in their tears.
“Despite the low prevalence of the virus found in tears, there is a potential risk of transmission through ocular routes. It is noteworthy that we observed a COVID-19-positive tear sample in patients with and without ocular symptoms. Therefore, it is important to consider the possibility of ocular transmission even in the absence of ocular manifestations,” the study authors wrote as quoted by Healio.
The findings of the study were published in the Cureus journal.