Abstract
Introduction The coronavirus disease 2019 (COVID-19) pandemic has placed
personal protective equipment (PPE) for healthcare workers (HCW) in the
spotlight. HCW’s face has been reported to be the body part most
commonly contaminated by body fluids. The aim of this narrative review
to examine the current evidence on face shield as a PPE for droplet or
aerosol prevention. Methods A literature search was conducted on the
PubMed, MedLine, and Embase databases, with the keywords “face
shield”, “visor”, and “droplet precaution”. Bibliographic search
was also undertaken. Results Respiratory droplet is particle with
diameter greater than 5µm, while aerosol are ≤5µm according to the World
Health Organisation. However, infection is not neatly separated into the
dichotomy of droplet versus airborne transmission route. Modelling and
simulation have shown the importance of the conjunctival mucosa as a
route of transmission of disease in blood splashes, droplets and
aerosols containing virus. The limited reports from SARS, COVID-19 and
influenza season supports its use. However, HCW do not routinely use
face shield if they consider the procedures to be unlikely to be
associated with potential contamination. They also erroneously believe
that prescription glasses is adequate protection. The issues associated
with eye shield use, may be less of a problem with face shield.
Conclusion Transmission of viruses is multimodal, and the conjunctival
mucosa presents a real risk for viral transmission. Eye and face
protection is important to prevent transmission of COVID-19.