Evaluation and comparison of conjunctival swab polymerase chain reaction results in SARS-CoV-2 patients with and without ocular manifestations.Indian J Ophthalmol. 2021 Aug; 69(8):2211-2214.IJ
The aim of this study was to evaluate and compare the presence of SARS-CoV-2 in tears of patients with and without ocular symptoms in SARS-CoV-2 positive patients.
The prospective observational study conducted on 60 consecutive SARS-CoV-2 positive patients with ocular complaints was compared with 60 controls who had no ocular manifestations. The tear samples were taken within 48 h of admission from both the eyes of the enrolled patients for evaluating the presence SARS-CoV-2 by reverse transcription-polymerase chain reaction.
Eleven cases (18.33%) tested positive for SARS-CoV-2 in tears on RT-PCR from cojunctival swab compared to 10 (16.66%) controls. The difference was not statistical significant. The difference between mean age of patients who tested positive or negative was also without statistical significance (P = 0.652), but the difference between patients who tested positive or negative by conjunctival swab for SARS-CoV-2 was statistically significant in terms of severity of COVID-19 disease (P = 0.0011), presence of comorbidity (P = 0.0015), mean TLC (P = 0.00498), and mean d dimer (P = 0.00465).
Though the percentage of patients with positive RT PCR from conjunctival secretions is significantly less than nasopharyngeal swabs, potential risk of transmission of SARS-Co-2 through tears cannot be ruled out. Moreover, SARS-CoV-2 can be present in tears irrespective of ocular involvement.