The coronavirus SARS-CoV-2 can be detected in the eyes of most patients infected, moreover, in some cases, the positivity of the ocular surfaces can exist even in the presence of a tampone rinofaringeo negative. These are the main results of a new research conducted in Northern Italy, led by scientists from the Ophthalmology Unit of the Territorial Social Health Authority (ASST) of the Seven Lakes and various departments of the University of Insubria in Varese. The researchers, coordinated by Professor Claudio Azzolini, professor at the Department of Medicine and Surgery of the Lombard university, reached their conclusions after conducting a qualitative and quantitative analysis on the presence of the coronavirus in the eyes of patients. admitted to intensive care per COVID-19 during the first wave of the pandemic. Specifically, 91 patients hospitalized at the ASST Ospedale Sette-Laghi between 9 April and 5 May of last year were involved, plus another 17 healthy volunteers as a control group (to test the validity of the swabs). The participants were in a slight majority women (55) and had an average age of 58.7 years.
Professor Azzolini and colleagues subjected all participants to conjunctival swab, as well as nasopharyngeal swabs and radiographs. Through a laboratory test called real-time reverse transcription polymerase chain reaction (rRT-PCR) hunted for viral RNA in biological samples taken from the eyes. As many as 52 of 91 patients tested positive for conjunctival swab, or 57.1 percent of the total. One of the most significant aspects of the research was that in a subgroup of 41 patients, a 63 percent agreement (95% CI, 41.0% -81.0%) was found between the positive results of the conjunctival and swab test. nasopharyngeal, when performed within days of each other. In fact, in 17 of these patients, the nasopharyngeal swab was negative, however in ten of them the conjunctival swab was positive. In simple terms, it can be positive for the conjunctival swab and negative for the “classic” one.
According to scientists, the coronavirus would be able to spread from the eyes to the rest of the body causing the infection, and it is for this reason that doctors, nurses and other health professionals who come into contact with positives must also wear the visor, goggles or other eye protection. “It is hypothesized that the virus can spread into the tear fluid of the lacrimal glands due to systemic viraemia, as has been shown for HIV,” the study authors write, and “it can spread throughout the body through the nasolacrimal duct. “This contagion occurs despite the use of masks,” the scholars add, citing the example of Wuhan ophthalmologist Li Wenliang, the young doctor who died of COVID-19 who was silenced by the Chinese police when he began to spread news. on the presence of the virus.
Experts consider the transmission through the respiratory droplets large (droplet) and small (aerosol) the main one, but it is still possible to get infected through other methods: i conjunctival fluids and the tears they could be one of them, although the authors of the new study could not determine the infectivity of the analyzed samples. According to the recent research “Ocular manifestations and viral shedding in tears of pediatric patients with coronavirus disease 2019: a preliminary report” conducted by scientists from the Bambino Gesù Hospital in Rome, the risk of transmission from tears would still be low. Since patients can test positive for conjunctival swab and negative for traditional swab, Professor Azzolini and colleagues indicate that the former – defined as “mildly invasive” – can be considered an additional diagnostic test. The details of the research “SARS-CoV-2 on Ocular Surfaces in a Cohort of Patients With COVID-19 From the Lombardy Region, Italy” have been published in the authoritative specialized scientific JAMA Ophthalmology.