ABSTRACT Purpose: This study aimed to evaluate the pre-sence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the ocular surface of individuals clinically suspected of coronavirus disease 2019 (COVID-19) and determine the accuracy of different approaches of molecular testing on the ocular surface based on the nasopharyngeal positivity status for COVID-19. Methods: A total of 152 individuals with suspected COVID-19 symptoms who simultaneously underwent nasopharyngeal and two different tear film collection techniques for quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) were included. Tears were collected and randomized: one eye had the filter strip for the Schirmer test and the contralateral eye had conjunctival swab/cytology in the inferior fornix. All patients underwent slit lamp biomicroscopy. The accuracy of various ocular surface collection techniques used for the detection of SARS-CoV-2 RNA was determined. Results: Of the 152 patients enrolled in the study, 86 (56.6%) had COVID-19 confirmed by nasopharyngeal PCR. Both tear film collection techniques detected viral particles: the Schirmer test was positive in 16.3% (14/86) and the conjunctival swab/cytology in 17.4% (15/86), with no statistically significant differences. No positive ocular tests were found among those with negative nasopharyngeal PCR tests. The overall agreement of the ocular tests was 92.7%, and in combination, the sensitivity would increase to 23.2%. The mean cycle threshold values in the nasopharyngeal, Schirmer, and conjunctival swab/cytology tests were 18.2 ± 5.3, 35.6 ± 1.4, and 36.4 ± 3.9, respectively. Compared with the nasopharyngeal test, the Schirmer (p=0.001) and conjunctival swab/cytology (p<0.001) tests had significantly different Ct values. Conclusion: The Schirmer (16.3%) and conjunctival swab (17.4%) tests were comparably capable of detecting SARS-CoV-2 RNA in the ocular surface by RT-PCR accurately based on nasopharyngeal status and demonstrated indistinct sensitivity and specificity. Simultaneous specimen sampling and processing from the nasopharyngeal, Schirmer, and conjunctival swab/cytology tests demonstrated significantly lower viral load in both ocular surface approaches than in the nasopharyngeal test. Ocular manifestations detected by slit lamp biomicroscopy were not associated with ocular RT-PCR positivity. Purpose presence pre sence SARSCoV2 SARSCoV SARS CoV (SARS-CoV-2 201 COVID19 COVID 19 (COVID-19 COVID19. 19. Methods 15 COVID-1 reversetranscriptase reverse transcriptase RTqPCR RT qPCR (RT-qPCR included randomized swabcytology cytology fornix SARS-CoV- determined Results 8 56.6% 566 56 6 (56.6% particles 163 16 3 16.3 14/86 1486 14 (14/86 174 17 4 17.4 15/86, 1586 15/86 , (15/86) differences 927 92 7 92.7% combination 232 23 23.2% 182 18 18. 53 5 5.3 356 35 35. 1 1.4 364 36 36. 39 9 3.9 respectively p=0.001 p0001 p 0 001 (p=0.001 p<0.001 (p<0.001 Conclusion (16.3% (17.4% RTPCR specificity (SARS-CoV- 20 COVID1 (COVID-1 COVID- SARS-CoV 56.6 (56.6 16. 14/8 148 (14/8 17. 158 15/8 (15/86 92.7 23.2 5. 1. 3. p=0.00 p000 00 (p=0.00 p<0.00 (p<0.00 (16.3 (17.4 (SARS-CoV (COVID- 56. (56. 14/ (14/ 15/ (15/8 92. 23. p=0.0 p00 (p=0.0 p<0.0 (p<0.0 (16. (17. (COVID (56 (14 (15/ p=0. p0 (p=0. p<0. (p<0. (16 (17 (5 (1 (15 p=0 (p=0 p<0 (p<0 ( p= (p= p< (p< (p
RESUMO Objetivo: Avaliar a presença de RNA de coronavírus 2 causador de síndrome respiratória aguda grave (SARS-CoV-2) na superfície ocular de indivíduos clinicamente suspeitos com COVID-19 e determinar a precisão de diferentes abordagens de testes moleculares na superfície ocular com base no status de positividade do RT-qPCR de nasofaringe para COVID-19. Métodos: 152 indivíduos com sintomas suspeitos para a COVID-19 foram submetidos a coleta de reação em cadeia da polimerase de nasofaringe simultaneamente a duas técnicas diferentes de coleta de filme lacrimal para RT-qPCR: aleatoriamente, um olho com a tira filtro do teste de Schirmer e, o olho contralateral, com citologia (swab) conjuntival no fórnice inferior. Todos os indivíduos foram submetidos à biomicroscopia com lâmpada de fenda. Resultados: Dos 152 pacientes, 86 (56,6%) tiveram a COVID-19 confirmada por PCR de nasofaringe. Ambas as técnicas de coleta detectaram partículas virais: o teste de Schirmer foi positivo em 16,3% (14/86) e a citologia conjuntival em 17,4% (15/86), sem diferenças estatisticamente significativas. Não houve testes oculares positivos entre aqueles com reação em cadeia da polimerase de nasofaringe negativo. A concordância geral dos testes oculares foi de 92,7% e, em combinação, a sensibilidade aumentaria para 23,2%. Os valores médios do limiar de ciclo nos testes de nasofaringe, Schirmer e citologia conjuntival foram 18,2 ± 5,3, 35,6 ± 1,4 e 36,4 ± 3,9, respectivamente. Conclusão: Os testes de Schirmer (16,3%) e swab conjuntival (17,4%) foram igualmente capazes de detectar RNA de SARS-CoV-2 na superfície ocular por RT-PCR e demonstraram sensibilidade e especificidade indistintas. A coleta simultânea de amostras ao processamento dos testes de RT-PCR de nasofaringe, Schirmer e citologia (swab) conjuntival demonstraram carga viral significativamente menor em ambas as abordagens da superfície ocular em comparação com o teste de nasofaringe. As manifestações oculares detectadas pela biomicroscopia com lâmpada de fenda não foram claramente associadas à positividade do RT-PCR ocular. Objetivo SARSCoV2 SARSCoV SARS CoV (SARS-CoV-2 COVID19 COVID 19 COVID-1 RTqPCR RT qPCR COVID19. 19. Métodos 15 aleatoriamente contralateral (swab inferior Resultados pacientes 8 56,6% 566 56 6 (56,6% virais 163 16 3 16,3 14/86 1486 14 (14/86 174 17 4 17,4 15/86, 1586 15/86 , (15/86) significativas negativo 927 92 7 92,7 combinação 232 23 23,2% 182 18 18, 53 5 5,3 356 35 35, 1 1, 364 36 36, 39 9 3,9 respectivamente Conclusão (16,3% (17,4% SARS-CoV- RTPCR indistintas (SARS-CoV- COVID1 COVID- 56,6 (56,6 16, 14/8 148 (14/8 17, 158 15/8 (15/86 92, 23,2 5, 3, (16,3 (17,4 SARS-CoV (SARS-CoV 56, (56, 14/ (14/ 15/ (15/8 23, (16, (17, (56 (14 (15/ (16 (17 (5 (1 (15 (