Ophthalmology practice in COVID-19 pandemic: Performance of rapid antigen test versus real time-reverse transcription polymerase chain reaction in a tertiary eye care institute in South India

ABSTRACT

Purpose: To assess the rapid antigen test (RAT) against the gold standard reverse transcription?polymerase chain reaction (RT?PCR) to screen COVID?19 infection in asymptomatic patients undergoing ophthalmic procedures. Methods: This was a retrospective hospital?based study. Point?of?care (PoC) RAT was performed using nasopharyngeal swab, while RT?PCR for SARS?CoV?2 viral RNA was performed using both nasopharyngeal and throat swabs. Results: A total of 629 patients were tested for SARS?CoV?2 by using both RAT and RT?PCR. Only one patient had tested positive for SARS?CoV?2 with both RAT and RT?PCR, while two patients had tested positive with RT?PCR after an initial negative RAT. The positivity rate for RAT was 0.15% (1/629), and that for RT?PCR was 0.47%. Percent agreement or proportion of agreement observed between the two tests was 99.68%, while Cohen’s kappa coefficient value was 0.49. The sensitivity of RAT in comparison to RT?PCR was 33.33%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 99.68%. Conclusion: The sensitivity and Cohen’s kappa coefficient in our study were low but that can be attributed to the overall low positivity rates with both RAT and RT?PCR. However, percent agreement observed between the two tests was very high. Therefore, we recommend initial screening of all the patients for COVID?19 symptoms followed by RAT before performing any ophthalmic surgical procedure to ensure the safety of the health care professionals as well as the patients.