Dear Editor,
We would like to propose a possible mechanism of protection by the use of contact lenses.
It is known that conjunctiva may be an entry point for SARS-COV-2 to infect respiratory tract [1]. Contact lenses cover the greater extent of the exposed to droplets ocular surface, and in conjugation with the antiviral properties of the tear film, they could considerably limit the danger of conjunctivitis. The tear film has antiviral properties, for instance contains the protein lactoferrin, and it is plausible that could inactivate viruses that were to come in contact with the tears. Therefore may prohibit viral entry into ocular surface cells [2].
Specifically, lenses could act as a protection shield against the inoculation of the SARS-COV-2 to the conjunctiva. Their protective role, even if some conjunctival arias are remain uncovered, may be of essential value as cornea, rather than conjunctiva has higher potential to be infected by SARS-CoV-2. The expression of both ACE2 and TMPRSS2 receptors, which mediate the viral entry in mucosa cells, is much higher in cornea rather than in conjunctiva cells, suggesting that conjunctiva would be less likely to be infected by SARS-CoV-2. Subsequently viral reproduction in ocular surface cells could be prevented as the ensuing spread of a great load of new viruses to nasal and nasopharyngeal mucosa by tears inducing a respiratory tract infection [1], [3].
Possible adhesion of the SARS-COV-2 on the surface of certain contact lenses, depending on their manufacturing process, may retard the transfer of viruses from the contact lenses, further diminishing the viral load. Transfer of virus would be influenced by the strength of adhesion to both moulds and lenses, as well as the effect, if any, of tears. Even though there have been no evidence available on the ability of coronaviruses to adhere to the main materials of contact lenses, some of commonest materials used in the molding process, such as polypropylene and polyoxymethylene, could bind SARS-COV-2 [2], [4]. The interaction between the mold surface and polymer solution will affect the surface finish of the contact lens and molding material may remain on the surface of contact lenses after the production process as mutual mass transfer takes place at the lens-mold phase boundary. The adhering mass particles cannot be separated from the lens even after washing for several days [5], [6].
Author contributions
Plotas P and Kagkelaris K contributed equally to the manuscript as co-first author.
Disclosure of interest
The authors declare that they have no competing interest.
Role of the funder/sponsor
None of the funders had a role in the preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
References
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