SARS-CoV-2 in Conjunctiva and Tears and Ocular Symptoms of Patients with COVID-19

Abstract

This study investigates the presence of SARS-CoV-2 in conjunctival secretions and tears and evaluates ocular symptoms in a group of patients with COVID-19. We included 56 hospitalized patients with COVID-19 in this cross-sectional cohort study. Conjunctival secretions and tears were collected using flocked swabs and Schirmer strips for SARS-CoV-2 reverse-transcriptase polymerase chain reaction (RT-PCR). Assessment of ocular surface manifestations included an OSDI (Ocular Surface Disease Index) questionnaire. Patients had been admitted to hospital for an average of 2.4 days (range 0–7) and had shown general symptoms for an average of 7.1 days (range 1–20) prior to ocular testing. Four (7.1%) of 56 conjunctival swabs and four (4%) of 112 Schirmer strips were positive for SARS-CoV-2. The mean E-gene cycle threshold values (Ct values) were 31.2 (SD 5.0) in conjunctival swabs and 32.9 (SD 2.7) in left eye Schirmer strips. Overall, 17 (30%) patients presented ocular symptoms. No association was found between positive ocular samples and ocular symptoms. This study shows that SARS-CoV-2 can be detected on the conjunctiva and tears of patients with COVID-19. Contact with the ocular surface may transmit the virus and preventive measures should be taken in this direction.

Detection of coronavirus in tear samples of hospitalized patients with COVID-19

“…Only a few studies in the literature comparing CT values in ocular and nasopharyngeal samples have been published. Ares et al, Karabela et al, and Gijs et al reported results similar to ours [ 18 , 26 , 27 ].…”

“…Hany et al, Arora et al, and Kaya et al reported higher rates of 28.57%, 28%, and 16%, respectively, than found in our study [ 10 – 12 ]. In some other studies, a lower positivity rate, ranging from 0.8 to 7, was found [ 13 – 18 ]. This variability could have been due to multiple factors, such as differences in hygiene practices, race, timing of conjunctival swab, technique of conjunctival swab removal, patient compliance, or different virus subtypes in different geographical regions.…”

“…In a study by Zhang et al, only one of 102 COVID-19 patients showed tear positivity, and the mean time of conjunctival sampling was 18.15 days [ 14 ]. Only in one study, SARS-CoV-2 RNA was detected in the conjunctival sample up to 27 days after disease onset, suggesting sustained viral replication [ 18 ].…”

Conjunctival Swabs Reveal Higher Detection Rate Compared to Schirmer Strips for SARS-CoV-2 RNA Detection in Tears of Hospitalized COVID-19 Patients

“…SARS-CoV-2 prevalence in tears has already been explored in other studies, ranging from 0% to 57% [ 27 , 28 ]. Most of these studies used only CS for tear collection [ 27 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], one study used only SS [ 43 ], and four other studies used both tear collecting methods [ 44 , 45 , 46 , 47 ]. Our study confirms previous findings that CS samples had a higher SARS-CoV-2 detection rate compared to SS samples, and the viral loads in tear samples were lower compared to nasopharyngeal samples [ 44 , 45 , 46 , 47 ].…”

“…Most of these studies used only CS for tear collection [ 27 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], one study used only SS [ 43 ], and four other studies used both tear collecting methods [ 44 , 45 , 46 , 47 ]. Our study confirms previous findings that CS samples had a higher SARS-CoV-2 detection rate compared to SS samples, and the viral loads in tear samples were lower compared to nasopharyngeal samples [ 44 , 45 , 46 , 47 ]. This is possibly because conjunctival scratching permits the collection of conjunctival cells, resulting in a larger volume of samples and, consequently, higher positivity rates.…”