Ocular Manifestations and Tear or Conjunctival Swab PCR Positivity for 2019-nCoV in Patients with COVID-19: A Systematic Review and Meta-Analysis

Background: Ocular tropism of respiratory viruses is a known fact. Many of the patients with COVID-19 also have concomitant ocular symptoms and in some of them, ocular symptoms are the first to appear which is followed by the occurrence of systemic symptoms. However till now no systematic review and meta-analysis have addressed this issue. Methods: In this regard, we have screened 5 literature databases (PubMed, Google Scholar, EMBASE, Medrixv and BioRixv) using appropriate keywords. "Ocular", "Ophthalmic", ophthal*, “conjunctiva”, “cornea’’, “retina”, “sclera”, “uvea”, “2019-nCov”, 2019 “novel corona virus”, COVID-19, corona virus disease-2019. We included published studies without language restriction from inception to 20 th March 2020. Studies reporting ocular manifestation of SARS-COV-2 patients were included. For the systematic review purpose, we included case report, case series and observational and any other types of study design which reported ocular manifestation or its complication of SARS-COV 2 infection. However for meta-analysis purpose, we included observational studies which included NCP patients (clinical or laboratory or both confirmed) and estimated the frequency of different ocular symptoms/complications in COVID-19 patients. Our primary objectives were determination of prevalence of different ocular symptoms in COVID-19 patients, estimation of incidence of RT-PCR positivity among conjunctival or tear samples and RT-PCR positivity among COVID-19 patients with conjunctivitis. We used MedCalc statistical software for the meta-analysis. We estimated the pooled proportion of patients presenting with the specific objectives. I 2 was used as a measure of heterogeneity. In case of high heterogeneity among the studies, data form random effect model was taking forward. Findings: A total of 7 studies were included in the systemic review and 6 studies were included in the final meta-analysis. In our study the proportion of patients reporting conjunctivitis/red eye was 3.175% (95% C.I. 1.165 to 6.127), however only 0.703% patients (95% C.I. 0.0358- 3.269) reported conjunctivitis as the first symptom of the disease. Among all COVID-19 patients, the proportion of conjunctival/tear sample that was positive for the virus (RT-PCR detection of SARS-CoV-2) was found to be 1.949% (95% C.I. 0.743-4.113). Interpretation: Although the proportion of patients presenting with ocular symptoms and PCR positivity were low, however the data collection process may remain a concern. In severely ill patients, the respiratory and other symptoms generally overrule ocular symptoms and in ICU settings especially with more severe disease, ocular examination may be suboptimal. Again for RT-PCR, the proportion of patients showing PT-PCR positive was low, however the tear sampling technique, day of sample collection amount of sample collected will also impact the RT-PCR positivity. Funding Statement: The authors stated the study was self-funded. Declaration of Interests: None of the authors have declared any competing interest.