Spanish Study Finds That SARS-CoV-2 Coronavirus Present in Tears And Ocular Secretions of Individuals With COVID-19
: A study by researchers from University of Santiago de Compostela-Spain and the University Hospital of Santiago de Compostel-Spain has found that the infectious form of the SARS-CoV-2 virus is present in the tears and ocular secretions of individuals with COVID-19.
The study team investigated the presence of SARS-CoV-2 in conjunctival secretions and tears and evaluated ocular symptoms in a group of patients with COVID-19.
The cross-sectional cohort study included 56 hospitalized patients with COVID-19. 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.
The study findings shos 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.
The study findings were published in the peer reviewed journal: Vision. https://www.mdpi.com/2411-5150/5/4/51/htm
To date it has been known that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is present in respiratory droplets. Transmission of SARS-CoV-2 through droplets can infect individuals, thus causing coronavirus disease 2019 (COVID-19).
This new study investigates the presence of SARS-CoV-2 in tears and eye secretions and describes the ocular symptoms in patients with COVID-19.
Typically, patients with COVID-19 often present with fever, cough, shortness of breath, muscle weakness and pain, as well as various gastrointestinal symptoms. Patients with severe COVID-19 may also develop bilateral pneumonia and hypoxemia. When severe COVID-19 leads to cytokine storms, multiple organs can get affected.
The SARS-CoV-2 has been detected in tears and conjunctival secretions, mostly in patients hospitalized with severe COVID-19. These patients also demonstrate ocular manifestations of the disease.
This cross-sectional cohort study involving 56 hospitalized patients, was a single-site study conducted at the University Hospital of Santiago de Compostela in Spain.
The participants were eligible to participate in the current study if they had reverse-transcriptase polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection from a nasopharyngeal swab and were within the first 20 days from the onset of symptoms. Patients from the intensive care unit or with a poor general condition were excluded from this study.
Samples of conjunctival secretions and tears were collected using flocked swabs and Schirmer strips for performing RT-PCR. The
scientists assessed the ocular surface manifestations through an Ocular Surface Disease Index (OSDI) questionnaire.
The mean age of the patients was 69 years, ranging from 27 to 89 years. The disease severity was mild in five patients, moderate in 30 patients, and severe in 21 patients. Of the 56 patients enrolled in this study, 32 were male and 24 were female.
The patients had been admitted to the hospital for an average of 2.4 days before ocular testing. The mean time from the onset of general symptoms until the collection of ocular samples was 7.1 days.
It was reported that the following percentage of patients had systemic comorbidity: hypertension, 48.2%; diabetes, 28.6%; cancer, 23.2%; heart disease, 21.4%; obesity, 17.9%; and chronic lung disease, 16%. Nineteen patients (33.9%) had reported previous ocular conditions, including cataract surgery (16.1%), glaucoma (5.4%), retinal vein occlusion (3.6%), strabismus (3.6%), uveitis (1.8%), refractive surgery (1.8%), and diabetic retinopathy (1.8%).
In all, four (7.1%) of the 56 conjunctival swabs samples and four (3.6%) of 112 Schirmer strips tested positive for SARS-CoV-2.
In the four patients with positive conjunctival swab samples, Schirmer strip samples were negative in both eyes in one patient, positive only in the left eye in two patients, and positive in both eyes in one patient. None of the patients had both a negative conjunctival swab and a positive Schirmer strip sample.
Interestingly there was no association observed between the RT-PCR test from ocular samples and ocular symptoms. Twenty-nine percent of patients with a negative RT-PCR and 25% of patients with positive ocular RT-PCR had ocular symptoms. Three of the patients had a moderate illness and one presented a severe course of the disease. Overall, 17 (30%) patients presented ocular symptoms.
study team concluded that the viral load was low on the ocular surface because the cycle threshold (Ct) values were high in ocular samples. The patient with positive conjunctival and tear samples in both eyes had a higher viral load in the eyes when compared to the other patients. Only one patient had a high viral load in the eyes than in the nasopharynx. Interestingly, this patient demonstrated more severe systemic disease.
The study team however did disclose that the study had certain ie a small sample size, as well as the fact that the nasopharyngeal and ocular samples were taken during different stages of the disease. This may affect the homogeneity of the results.
Furthermore the study team could not perform slit lamp examinations or biomicroscopy to examine the eyes of the patients for any abnormalities or problems.
The study findings show that SARS-CoV-2 can be detected in the conjunctiva and tears of patients with COVID-19. The 7.1% prevalence of SARS-CoV-2 in conjunctival samples found in this study is comparable to previously reported rates.
The study findings and previous studies indicate that the ocular surface can act as an entry point and reservoir for the transmission of SAR-CoV-2. Contact with the ocular surface may transmit the virus; therefore, commercial ocular antiseptics may help with avoiding transmission and preventing ocular symptoms during COVID-19 infection.
Importantly health care professionals, particularly eye care providers, should be aware of ocular transmission and follow strict disinfection protocols.
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