Identification of SARS-CoV-2 on the ocular surface in a cohort of COVID-19 patients from Brazil

Abstract

In this cross-sectional study, we investigate the presence of Severe Acute Respiratory Syndrome Coronavirus 2 Ribonucleic Acid (SARS-CoV-2 RNA) in the tears of hospitalized COVID-19 patients. After laboratory confirmation of SARS-CoV-2 infection by reverse transcription polymerase chain reaction (RT-PCR) analysis, tear samples from both eyes of each patient were collected using conjunctival swab for RT-PCR. Detailed demographic profile, systemic and ocular symptoms, comorbidities, clinical, ancillary, and ocular manifestations were evaluated. Of the 83 patients enrolled in the study, 7 (8.43%) had SARS-CoV-2 RNA detected in the tear samples. Neutrophils’ count, C-reactive protein, and D-dimer were higher in patients with SARS-CoV-2 detected in tears than in patients without virus in ocular surface samples. One patient with SARS-CoV-2 in tears showed mild ocular eyelid edema, hyperemia, and chemosis. No relevant ocular manifestations were detected in the other patients. Although the levels of viral RNA on ocular surface samples were low for most patients (5/7), with positivity only for gene N and CT higher than 30, two patients were positive for all viral targets tested ( N, E, and RpRd), with viral load near 1 × 105 ePFU/mL, indicating that the ocular transmission of SARS-CoV-2 is a possibility that needs to be considered, especially in the hospital environment. Further studies need to be conducted to demonstrate whether infective viral particles could be isolated from tears.

Ocular tropism of SARS-CoV-2 in animal models with retinal inflammation via neuronal invasion following intranasal inoculation

“…Clinical studies have reported that the time required for ocular manifestation varied from 15 days to two months after the infection or symptom onset 8 , 62 . Moreover, Colavita et al detected viral RNA in the ocular swabs with lower Ct values than those in the nasal swabs of a patient with COVID-19 who suffered from ocular manifestations between 21 and 27 days from the onset of symptoms 63 .…”

“…In contrast, a cross-sectional study in Italy reported the presence of viral RNA in the conjunctival swabs of 52 of 91 patients with COVID-19, with a high rate of detection in patients with severe disease 6 . Other cross-sectional studies in China 7 and Brazil 8 , and post-mortem examinations 9 , 10 also reported viral RNA detection in conjunctival swabs or in the aqueous humour of patients with or without ocular manifestations.…”

Ocular tropism of SARS-CoV-2 with retinal inflammation through neuronal invasion in animal models

“…Clinical studies have reported that the time required for ocular manifestation varied from 15 days to two months after the infection or symptom onset (Gasparini et al, 2021;Yan et al, 2020).…”

“…Clinical studies have reported that the time required for ocular manifestation varied from 15 days to two months after the infection or symptom onset (Gasparini et al, 2021; Yan et al, 2020). Moreover, Colavita et al detected viral RNA in ocular swabs with lower Ct values than those in nasal swabs between 21 and 27 days from the symptom onset of a patient with COVID-19 who suffered from ocular manifestations (Colavita et al, 2020).…”

“…In contrast, a cross-sectional study in Italy reported that viral RNA was found on the conjunctival swabs of 52 of 91 patients with COVID-19, with a high rate of detection in severe patients (Azzolini et al, 2021). Other crosssectional studies in China (Li et al, 2021) and Brazil (Gasparini et al, 2021) and post-mortem examinations (Penkava et al, 2021;Sawant et al, 2021) also reported the detection of viral RNA using conjunctival swabs or in the aqueous humor of the patients with or without ocular manifestations.…”