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SARS-CoV-2 on Ocular Surfaces in a Cohort of Patients With COVID-19 From the Lombardy Region, Italy

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Key Points

Question  What is the qualitative and quantitative presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the ocular surface in patients with coronavirus disease 2019 (COVID-19) hospitalized in intensive care units at a university hospital in Lombardy, Italy?

Findings  Using reverse transcription–polymerase chain reaction assay, this study found that SARS-CoV-2 was present on the ocular surface in 52 of 91 patients with COVID-19 (57.1%). The virus may also be detected on ocular surfaces in patients with COVID-19 when the nasopharyngeal swab is negative.

Meaning  These results suggest that SARS-CoV-2 may diffuse from ocular surfaces to the body.

Abstract

Importance  Since February 2020, coronavirus disease 2019 (COVID-19) has spread rapidly all over the world, with an epidemiological cluster in Lombardy, Italy. The viral communicability may be mediated by various body fluids, but insufficient information is available on the presence of the virus in human tears.

Objectives  To investigate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in tears collected from patients with COVID-19 by means of real-time reverse transcriptase–polymerase chain reaction (rRT-PCR) assay and to assess the association of virus presence with concomitant clinical conditions.

Design, Setting, and Participants  Cross-sectional study conducted between April 9 and May 5, 2020. The setting was intensive care units at Azienda Socio-Sanitaria Territoriale (ASST) Sette-Laghi Hospital, University of Insubria, in Varese, Lombardy, Italy. A conjunctival swab was performed in 91 patients hospitalized for COVID-19, which was clinically diagnosed by rRT-PCR assay on nasopharyngeal swabs and by radiological imaging. Conjunctival swabs from 17 additional healthy volunteer participants with no symptoms of COVID-19 were examined to evaluate the availability and applicability of the conjunctival swab test.

Exposure  SARS-CoV-2 detection by means of rRT-PCR assay performed on the collected samples obtained by conjunctival swabs.

Main Outcomes and Measures  Conjunctival swab and nasopharyngeal swab results are reported, as well as demographic and clinical data.

Results  A total of 108 participants (mean [SD] age, 58.7 [14.2] years; 55 female and 53 male) were tested for SARS-CoV-2 using rRT-PCR assay, including 91 patients hospitalized with COVID-19 and 17 were healthy volunteers. SARS-CoV-2 was found on the ocular surface in 52 of 91 patients with COVID-19 (57.1%; 95% CI, 46.3%-67.5%), with a wide variability in the mean viral load from both eyes. Among a subset of 41 patients, concordance of 63.0% (95% CI, 41.0%-81.0%) was found between positive conjunctival and nasopharyngeal swab test results when performed within 2 days of each other. In 17 of these patients, nasopharyngeal swab results were negative for SARS-CoV-2. In 10 of these 17 patients, conjunctival swab results were positive for the virus.

Conclusions and Relevance  In this study, SARS-CoV-2 RNA was found on the ocular surface in a large part of this cohort of patients with COVID-19, although the infectivity of this material could not be determined. Because patients may have positive test results with a conjunctival swab and negative results with a nasopharyngeal swab, use of the slightly invasive conjunctival swab may be considered as a supplementary diagnostic test.

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Article Information

Accepted for Publication: October 10, 2020.

Published Online: March 4, 2021. doi:10.1001/jamaophthalmol.2020.5464

Corresponding Author: Claudio Azzolini, MD, Unit of Ophthalmology, Azienda Socio-Sanitaria Territoriale (ASST) dei Sette Laghi, Department of Medicine and Surgery, University of Insubria, Via Guicciardini 9, 21100 Varese, Italy (claudio.azzolini@uninsubria.it).

Author Contributions: Dr Azzolini had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Azzolini, Dentali, Cabrini, Carcano, Maffioli.

Acquisition, analysis, or interpretation of data: Azzolini, Donati, Premi, Baj, Siracusa, Genoni, Grossi, Azzi, Sessa, Dentali, Severgnini, Minoja, Cabrini, Chiaravalli, Veronesi, Tagliabue.

Drafting of the manuscript: Azzolini, Donati, Premi, Baj, Azzi, Dentali, Severgnini, Tagliabue.

Critical revision of the manuscript for important intellectual content: Azzolini, Donati, Premi, Siracusa, Genoni, Grossi, Sessa, Minoja, Cabrini, Chiaravalli, Veronesi, Carcano, Maffioli.

Statistical analysis: Veronesi.

Obtained funding: Azzolini.

Administrative, technical, or material support: Azzolini, Premi, Baj, Siracusa, Genoni, Grossi, Azzi, Dentali, Minoja, Tagliabue.

Supervision: Azzolini, Donati, Sessa, Severgnini, Cabrini, Chiaravalli, Carcano, Maffioli.

Conflict of Interest Disclosures: Dr Azzolini reported that his university received grants from Bayer and Novartis for ophthalmic projects and that Bayer, Novartis, Alcon, Allergan, Santen, Topcon, Thea, Dompé, and Bausch & Lomb provided grant funds to a nonprofit Italian ophthalmic association he chaired from 2016 to 2019. No other disclosures were reported.

Funding/Support: This study received financial support from the research resources of the Department of Medicine and Surgery, University of Insubria, Varese, Italy.

Role of the Funder/Sponsor: The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: We gratefully acknowledge the nursing staff of the various departments involved in the care of patients with COVID-19 and the laboratory personnel involved in this study. We thank Andrea Falco, BEng, for construction and management of the dedicated database for the electronic medical records (Eumeda platform hosted by Aruba Business srl). He was not compensated for his contributions.

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