Virological and cytological changes in tears and conjunctiva of patients with COVID-19.

PURPOSE

To analyze the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in tears/conjunctival epithelium and assess the cytomorphological changes in the conjunctival epithelium of coronavirus disease 2019 (COVID-19) patients.

METHODS

In this pilot study, patients with moderate to severe COVID-19 were recruited from the COVID ward/intensive care unit of the institute. Tears and conjunctival swabs were collected from COVID-19 patients and sent to the virology laboratory for reverse transcription polymerase chain reaction (RT-PCR) testing. Conjunctival swabs were used to prepare smears, which underwent cytological evaluation and immunocytochemistry for SARS-CoV-2 nucleocapsid protein.

RESULTS

Forty-two patients were included. The mean age of participants was 48.61 (range: 5-75) years. Seven (16.6%) patients tested positive for SARS-CoV-2 ribonucleic acid in tears samples, four (9.5%) of which were positive on conjunctival swab by RT-PCR in the first test. Cytomorphological changes were observed significantly more in smears from patients with positive RT-PCR on tear samples, including bi-/multi-nucleation (p = 0.01), chromatin clearing (p = 0.02), and intra-nuclear inclusions (p < 0.001). One case (3.2%) showed immunopositivity for SARS-CoV-2; this patient had severe disease and the lowest Ct values for tear and conjunctival samples among all positive cases.

CONCLUSION

Conjunctival smears from patients with COVID-19 revealed cytomorphological alterations, even in the absence of clinically significant ocular infection. However, viral proteins were demonstrated within epithelial cells only rarely, suggesting that although the conjunctival epithelium may serve as a portal for entry, viral replication is possibly rare or short-lived.