ArticleThe ocular surface2020
ACE2 and TMPRSS2 are expressed on the human ocular surface, suggesting susceptibility to SARS-CoV-2 infection.
Article in The ocular surface, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 205 papers, 4 of them syntheses that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
205 citing papers in PubMed, 4 syntheses or guidelines pooled it, 340 citations in OpenAlex.
- Ocular transmission and manifestation for coronavirus disease: a systematic review.International health · 2022Pooled it
- Pooled Prevalence Estimate of Ocular Manifestations in COVID-19 Patients: A Systematic Review and Meta-Analysis.Iranian journal of medical sciences · 2022Pooled it
- An Eye on COVID-19: A Meta-analysis of Positive Conjunctival Reverse Transcriptase-Polymerase Chain Reaction and SARS-CoV-2 Conjunctivitis Prevalence.Optometry and vision science : official publication of the American Academy of Optometry · 2021Pooled it
- On the whereabouts of SARS-CoV-2 in the human body: A systematic review.PLoS pathogens · 2020Pooled it
- Neurological impairment in long COVID: implications for neurodegenerative disease.Journal of translational medicine · 2026Review
- Molecular insights into the anti-COVID-19 activity of reduced (quinol) and oxidized (quinone) forms of coenzyme Q10.Naunyn-Schmiedeberg's archives of pharmacology · 2026Article
- Women's Cardiovascular Disease and Stroke Risk Stratification Using a Precision and Personalized Framework Embedded with an Explainable Artificial Intelligence Paradigm: A Narrative Review.Diagnostics (Basel, Switzerland) · 2026Review
- Evaluation of the choroidal structural and vasculature changes following COVID-19 infection and vaccination using optical coherence tomography angiography.International journal of retina and vitreous · 2026Article
- Ocular Symptoms as a Marker of Dysautonomia in Long-COVID Patients: A Cross-Sectional Analysis.Brain sciences · 2026Article
- Impact of COVID-19 on corneal endothelial density and morphology: a cross-sectional study in convalescent patients.Frontiers in medicine · 2026Article
- Viral mechanisms, tropism, and clinical relevance regarding the ophthalmic manifestations of SARS-CoV-2 infection.International journal of ophthalmology · 2026Review
- External Ocular Manifestations among Patients Diagnosed with Coronavirus Disease 2019 in a Referral Center in the Philippines.Acta medica Philippina · 2026Article
- Intravitreal exposure to the SARS-CoV-2 spike protein is associated with aggravated retinal lesions in a murine model of central retinal vein occlusion.Frontiers in medicine · 2026Article
- Ophthalmic complications associated with COVID-19: a large US national database analysis.Eye (London, England) · 2025Article
- Functional crosstalk between the lung and eye: a new frontier in chronic lung diseases.Archives of toxicology · 2025Review
- Ocular and Neurological Sequelae in Long COVID: Dry Eye, Asthenopia, Sleep Disorders, Asthenia, and Restless Legs Syndrome-A Case Report with Literature Review.Life (Basel, Switzerland) · 2025Article
- Article
- Atypical presentation of acute macular neuroretinopathy: a case description.Quantitative imaging in medicine and surgery · 2025Article
- Impact of COVID-19 on Ocular Surface Health: Infection Mechanisms, Immune Modulation, and Inflammatory Responses.Viruses · 2025Review
- Mutations in ace2 gene modulate cytokine levels and alter immune responses inFrontiers in immunology · 2025Article
145 more citing papers are in PubMed but not listed here.
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Authors and funding
6 authors at 1 institution in 2 countries.
Funding
Abstract
purposeConjunctival signs and symptoms are observed in a subset of patients with COVID-19, and SARS-CoV-2 has been detected in tears, raising concerns regarding the eye both as a portal of entry and carrier of the virus. The purpose of this study was to determine whether ocular surface cells possess the key factors required for cellular susceptibility to SARS-CoV-2 entry/infection.
methodsWe analyzed human post-mortem eyes as well as surgical specimens for the expression of ACE2 (the receptor for SARS-CoV-2) and TMPRSS2, a cell surface-associated protease that facilitates viral entry following binding of the viral spike protein to ACE2.
resultsAcross all eye specimens, immunohistochemical analysis revealed expression of ACE2 in the conjunctiva, limbus, and cornea, with especially prominent staining in the superficial conjunctival and corneal epithelial surface. Surgical conjunctival specimens also showed expression of ACE2 in the conjunctival epithelium, especially prominent in the superficial epithelium, as well as weak or focal expression in the substantia propria. All eye and conjunctival specimens also expressed TMPRSS2. Finally, Western blot analysis of protein lysates from human corneal epithelium obtained during refractive surgery confirmed expression of ACE2 and TMPRSS2.
conclusionsTogether, these results suggest that ocular surface cells including conjunctiva are susceptible to infection by SARS-CoV-2, and could therefore serve as a portal of entry as well as a reservoir for person-to-person transmission of this virus. This highlights the importance of safety practices including face masks and ocular contact precautions in preventing the spread of COVID-19 disease.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.