Sze C Ong1, Jun X Yap2, Terrence Y F Tay2, Yin Mo1,3,4,5, Seng C Loon2, Victor Koh1,2. 1. Yong Loo Lin School of Medicine, National University of Singapore. 2. Department of Ophthalmology. 3. Division of Infectious Disease, University Medicine Cluster, National University Hospital, Singapore. 4. Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. 5. Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
Abstract
PURPOSE OF REVIEW: The use of slit lamp shields has been recommended by the American Academy of Ophthalmology as an infection control measure during the coronavirus disease 2019 pandemic. However, there is limited evidence regarding its efficacy to reduce viral transmission risks. We aim to provide an evidence-based approach to optimize the use of slit lamp shields during clinical examination. RECENT FINDINGS: Respiratory droplets from coughing and sneezing can travel up to 50 m/s and over a distance of 2 m, with a potential area of spread of 616 cm. Slit lamp shields confer added protection against large droplets but are limited against smaller particles. A larger shield curved toward the ophthalmologist and positioned closer to the patient increases protection against large droplets. A potential improvement to the design of such shields is the use of hydrophilic materials with antiviral properties which may help to minimize splashing of infectious droplets, reducing transmission risks. These include gold or silver nanoparticles and graphene oxide. SUMMARY: Slit lamp shields serve as a barrier for large droplets, but its protection against smaller droplets is undetermined. It should be large, positioned close to the patient, and used in tandem with routine basic disinfection practices.
PURPOSE OF REVIEW: The use of slit lamp shields has been recommended by the American Academy of Ophthalmology as an infection control measure during the coronavirus disease 2019 pandemic. However, there is limited evidence regarding its efficacy to reduce viral transmission risks. We aim to provide an evidence-based approach to optimize the use of slit lamp shields during clinical examination. RECENT FINDINGS: Respiratory droplets from coughing and sneezing can travel up to 50 m/s and over a distance of 2 m, with a potential area of spread of 616 cm. Slit lamp shields confer added protection against large droplets but are limited against smaller particles. A larger shield curved toward the ophthalmologist and positioned closer to the patient increases protection against large droplets. A potential improvement to the design of such shields is the use of hydrophilic materials with antiviral properties which may help to minimize splashing of infectious droplets, reducing transmission risks. These include gold or silver nanoparticles and graphene oxide. SUMMARY: Slit lamp shields serve as a barrier for large droplets, but its protection against smaller droplets is undetermined. It should be large, positioned close to the patient, and used in tandem with routine basic disinfection practices.