Covid, ozone-based ophthalmic gel being developed to protect the eyes
“A stabilised ozone-based ophthalmic gel could act as a barrier against the entry of the SARS CoV-2 virus through the eyes, thus acting as a kind of ‘mask’ for the eyes, to be ‘worn’ together with the classic surgical mask that covers the nose and mouth.
This is the idea behind a study published in the August issue of Translational Vision Science & Technology, signed by researchers from the Università Cattolica del Sacro Cuore in Rome and the University of Ferrara”.
This is the opinion of the Irccs Agostino Gemelli Foundation, where Professor Stanislao Rizzo, Professor of Ophthalmology at the Catholic University and Director of the Ophthalmology Unit at Gemelli, is one of the leading figures in the study on ophthalmic gel.
“Ozone-based ophthalmic gels are already used to alleviate the symptoms of inflammatory eye diseases, including those of infectious origin,’ Professor Rizzo explains. ‘Our study suggests that they could also have a barrier effect against viruses entering the eye or the nasolacrimal system.
However, this is an in vitro study,’ Rizzo points out, ‘and the results will have to be confirmed by studies on animal models and in humans.
THE EYES: A POORLY UNDERSTOOD ENTRY ROUTE FOR THE COVID-19 VIRUS
The SARS CoV-2 virus ‘can also enter the body through the eyes, as a member of the US National Expert Panel on Pneumonia sent to Wuhan for an inspection discovered to his cost,’ explains the note from Irccs Gemelli. ‘The man, who was not wearing eye protection, first developed conjunctivitis, then classic Covid-19 pneumonia.
Other studies have shown that the virus can remain in the eyes even several weeks after the acute phase of the disease.
In short, the eyes are a target organ for SARS CoV-2, particularly in the presence of minor damage, such as that which occurs in dry eye syndrome.
In Covid-19 patients, it is mainly the goblet-shaped mucus cells that are affected, whereas the cornea and conjunctival cells, perhaps because they are protected by the tear film that renews itself every five minutes, seem to be more protected from infection, unless you have a condition like dry eye syndrome.
This observation has led us to think that the tear film can also act as a protective barrier against the virus,” reveals the Gemelli Foundation note, “but in reality this is a double-edged sword, because if the virus manages to penetrate the tear layer, its drainage determines its arrival in the naso-lacrimal system, from where SARS CoV-2 can easily penetrate into the body, through its preferred route of access, the nose.
OZONE EYE DROPS
One solution is therefore to enhance the barrier effect of tears against SARS CoV-2: “These observations,” explains Professor Rizzo, “led to the idea of enhancing the barrier effect of tears against SARS CoV-2 using a special ozone-based eye drop.
The antimicrobial properties of ozone have long been known, probably linked to its ability to induce temporary oxidative stress (reacting with polyunsaturated fatty acids and water on the surface of the eyes induces the production of hydrogen peroxide); this in turn stimulates the production of Nrf2 (nuclear factor-erythroid 2-related factor 2), which activates the transcription of a series of anti-oxidant factors, such as superoxide dismutase and glutathione peroxidase”.
“Ozone has long been used in medicine to disinfect and treat infectious diseases, given its ability to inactivate bacteria, viruses, fungi, yeasts and even protozoa,’ the note stresses. ‘In particular, its antiviral activity occurs by damaging the viral capsid and altering viral replication through peroxidation.
How can a gas like ozone be ‘trapped’ in a medical device?
“As a gas,’ explains Professor Rizzo, ‘ozone is very unstable, but to make it suitable for topical use, it can be stabilised by reacting it with a monounsaturated fatty acid such as oleic acid to create so-called ‘ozonated oils’, which retain the same properties as gaseous ozone and are well tolerated by the tissues.
Ozone oils in nanoformulation are already being used in the form of eye drops or ophthalmic gels to alleviate the symptoms of inflammatory eye diseases, including those of infectious origin; ozone also facilitates the healing of corneal damage by minimising the risk of scarring and opacification of the cornea.
Can ozone block the entry of SARS CoV-2 into cells on the surface of the eye?
The study, just published in Translational Vision Science & Technology, assessed in vitro the effect of an ozone-based liposomal ophthalmic gel on human corneal epithelial cells infected with SARS CoV-2,” says the Gemelli note.
The objective of the study,” explains the director of the Ophthalmology Unit at Gemelli, “was to evaluate whether this ophthalmic gel could prevent infection by SARS CoV-2 in the superficial tissues of the eye and to evaluate whether, in patients with dry eye syndrome, it could help restore the integrity of the eye surface, repairing and regenerating the conjunctival microvilli.
In this study, the ozone-based ophthalmic gel inhibited viral replication and virus entry into cells on the surface of the eye (corneal and conjunctival).
Ozone ophthalmic gel has also been shown to restore cell regeneration and control inflammation in dry eye syndrome.
Professor Rizzo concludes: “While we are waiting for a vaccine to stop the spread of the virus, there are still few measures that can be taken to reduce the risk of contagion (mask, social distancing, frequent hand washing).
And the ocular surface is a potential route of entry for the virus, particularly in the case of tear film abnormalities, as in dry eye syndrome.
If the results of this research were to be confirmed by studies on animal models and in humans, it would therefore be conceivable to propose the topical administration of ozone-based ophthalmic gels to prevent the entry of SARS CoV-2 through the ocular surface,’ Rizzo points out, ‘a protective measure to be recommended first of all to healthcare workers and then possibly extended to the whole population.