COVID-19 Conjunctivitis

Abstract

The outbreak of new Cov-2 epidemic was detected in December 2019 in the city of Wuhan, China, caused by Severe Acute Respiratory Syndrome Coronavirus −2 and started its rapid spread througth the world. The World Health Organisation (WHO) declared a public health emergency of international concern (PHEIC) on the 30th of January 2020. -2 infection can present with spectrum of clinical manifestations, primary of upper respiratory tract and in some cases, especially in immunocompromised patients can cause changes in lower respiratory tract such as pneumonia and bronchitis. Conjunctivitis is not a common manifestation of SARS-Cov-2 infection. It should however be kept in mind that patients with ocular manifestations and symptoms can represent the COVID-19 cases. CoVs can produce several ocular manifestations from conjunctivitis, uveitis – anterior and posterior, retinitis and optic neuritis.

1. Introduction

The outbreak of new Cov-2 epidemic was detected in December 2019 in the city of Wuhan, China. It is caused by Severe Acute Respiratory Syndrome Coronavirus −2 (SARS-CoV-2) and started its rapid spread through the world [1]. The World Health Organization (WHO) declared a public health emergency of international concern (PHEIC) on the 30th of January 2020 [2].

CoV-2 infection, among other clinical presentations can also affect the eye and cause conjunctivitis, uveitis – anterior and posterior, retinitis and optic neuritis. In this chapter the CoV-2 ocular surface manifestation are divided in two different divisons- CoV-2 conjunctivits as an rare and uncommon manifestation of CoV-2 infection and ocular CoV-2 transmision since conjunctiva and conjunctival discharge are detected as a possible route of SARS-Cov-2 transmission.

The data about CoV-2 ocular manifestations are sparse. We analised the number of publications of conjunctivitis, SARS-CoV-2, COVID 19, ocular manifestations as key words was in PubMed, WoS, and Scopus. Published data are divided into two periods of time, year 2004 and 2005 in the outbreak of the first epidemic of CoVs and the period of recent ongoing epidemic since the outbreak in Dec 2019.

2. Conjunctivitis

CoV -2 infection can present with spectrum of clinical manifestations, primary of upper respiratory tract [3] and in some cases, especially in immunocompromised patients can cause changes in lower respiratory tract such as pneumonia and bronchitis [4]. Conjunctivitis is not a common manifestation of SARS-Cov-2 infection. However it should be kept in mind that patients with ocular manifestations and symptoms can represent the COVID-19 cases [5]. Coronaviruses (CoVs) can produce several ocular manifestations from conjunctivitis, uveitis – anterior and posterior, retinitis and optic neuritis. The data on the topic are sparse and as the epidemic continues more data should be available and better understanding of the disease is to be achieved [6].

The first reports suggesting CoVs affecting the eye dates from year 2004 and 2005 in patients – primary children with respiratory illness and conjunctivitis. Retrospective studies showed that 17% of patients with CoV-NL63 infection with primary upper and lower respiratory tract illnes had developed conjunctivitis [7].

The route of how CoVs ends up in the eye is not yet clear. The possible ways are from infected droplets, migration from the upper respiratory tract through the nasolacrimal duct or hematogenous spread and infection of the lacrimal gland [8, 9]. Most of the data are from the epidemic in 2004 and since the epidemic died down the research did not continue and the questions remained unanswered. The question emerged again the light of the new ongoing epidemic.

In 2020 there has been a report of the first SARS-CoV-2 infected patient with also an ocular infection in Wuhan [10] and it emerged the need to research the topic again [11]. Majority of studies conducted come from China and the first study in Europe was performed by a group of authors from Spain [12]. The frequency of conjunctivitis in COVID-19 disease is not yet specified, with different data from 0.8% in some to 3% in other and up to 31.6% in different studies conducted in China [13, 14, 15].

The European, Spanish study showed that 11.6% of the patients diagnosed with COVID 19 presented with some symptoms of conjunctivitis [12].

3. Clinical presentation and differential diagnosis

Mucopurulent discharge, tearing and foreign body sensation, follicular reaction, conjunctival hyperemia and discharge are the most common symptoms of conjunctivitis. The median time of onset of ocular symptoms is 6 days and the duration of symptoms 3 days.

SARS-CoV2 conjunctivitis can be similar to other viral infections mostly adenoviral. SARS-CoV-2 is usually unilateral and unlike one of adenoviral aethyology, rarely bilateral [16]. The onset in both scenarios is abrupt, injection more severe in adenoviral, similar folicular reaction and chemosis. Petechial hemorrhage, corneal infiltrates and membrane and pseudomembrane formation is more often detected in adenoviral conjunctivitis and discharge is more prominent.

There is a low rate of positive PCR test for SARS-CoV-2 RNA in tears and conjunctival discharge in patients with conjunctivitis presuming the false negativity. Also since the symptoms could be mild and patients do not have visual impairment it can go unnoticed the prevalence can be underestimated.

4. Duration and therapy

The duration of SARS-CoV-2 conjunctivitis is usually 3–4 days and it is a rapid self-limited disease. It ceases with no specific treatment. There are no clinical evidence of efficacy of topical antibotic or corticosteroid therapy. It is sometimes used as a prevention of a bacterial superinfection but it is generaly not recomended. Lubricants, gels and ointments can be used as a symptomatic therapy. Potential sequelae are not yet enough investigated.

5. Ocular symptoms and other CoV-2 infection manifestations

The connection between ocular symptoms and severity of pulmonary disease is yet to be investigated. The data in some studies imply that patients with conjunctivitis are more often presented with more severe COVID-19 – higher white blood cells and neutrophile count, levels of procalcitonin, C-reactive protein and lactate dehydrogenase [17]. Some suggestions emphasize the importance of hosts characteristics and site of inoculation.

6. Transmission

Health care workers are at special risk for SARS-CoV-2 infection due to high incidence of long term end repeated exposure, protected as well as unprotected.

Conjunctiva and conjunctival discharge is a possible route of SARS-Cov-2 transmission.

Presence of virus particles in conjunctival swabs, tear swabs and conjunctival scrappings has been investigated in several studies with different outcomes. Case series from Singapore first detected SARS-CoV in tears of 3of 36 tested patients sampled within 9 days of onset of disease (in the early phase). This case series has important implications for the ophthalmology practice since reported with the detection of the SARS-CoV from tears [18].

Considering the new and ongoing epidemic several studies were conducted in China and analyzed tears and conjunctival secretions from SARS-Cov-2 infected patients. In study conducted in Wuhan 2.8% of tested patients (of 72 tested) were confirmed SARS-CoV-2 RNA in conjunctival discharge [19] while in the study conducted in Hangzhou (on 30 patients) only one sample tested positive on presence of visus in PCR results [20]. Study from Wuhan investigated 67 cases of probable or confirmed COVID-19 infection. They found positive PCR result in one sample of conjunctival swab and two possible positive samples. None of the tested patients had ocular symptoms. The sample was taken from one patient with symptoms of conjunctivitis and the PCR test was negative [21].

The study conducted in Italy (Lombardia) SARS-CoV-2 was found in 57.1% of patients on the ocular surface with a variability of viral load from both eyes [22]. The infectivity of the material was not determined but the results suggested that the test can be positive in conjunctival swab and negative in nasopharingeal swab.

Authors from Croatia emphasize the importance of early detection of possible ocular manifestations and the need for precaution in order to prevent transmission through ocular secretions [23].

Besides frequent hand washing they emphasize the need for immediate disinfection of ophthalmic instruments, especially those in direct contact with patient’s mucosal membranes.

Considering the several study results we can presume that the conjunctiva and ocular surfaces are rearly detected in presence of SARS-Cov-2 but have to be considered and investigated in the future.

7. Conclusion

Ocular manifestations of SARS-CoV-2 infection including conjunctivitis are incommon. If present, conjunctivitis is usually selflimited disease with mild symptoms and of limited duration. Important but not yet investigated topic is a presence of CoV in conjunctival swabs in asymptomatic patients and in patients wit other manifestations of CoV-2 infection with no ocular symptoms. Potential viral transmision via conjunctival dicharge and secretions is yet to be investigated. The importance of precaution in contact with mucosal membranes including conjunctiva has to be emphasysed.