Quantitative High-speed Assessment of Droplet and Aerosol From an Eye After Impact With an Air-puff Amid COVID-19 Scenario

• Published in: Journal of glaucoma Vol. 29; no. 11; pp. 1006 - 1016
• Main Authors: Shetty, Rohit, Balakrishnan, Nikhil, Shroff, Sujani, Shetty, Naren, Kabi, Prasenjit, Roy, Durbar, Joseph, Sophia M., Khamar, Pooja, Basu, Saptarshi, Sinha Roy, Abhijit
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins 01-11-2020; Copyright Wolters Kluwer Health, Inc. All rights reserved
• Subjects: Adolescent; Adult; Aerosols - chemistry; Betacoronavirus; Coronavirus Infections - transmission; COVID-19; Environmental Monitoring; Female; Fluorescein - administration & dosage; Fluorescent Dyes - administration & dosage; Humans; Infectious Disease Transmission, Patient-to-Professional - prevention & control; Intraocular Pressure - physiology; Lubricant Eye Drops - administration & dosage; Male; Optical Imaging; Pandemics; Pneumonia, Viral - transmission; SARS-CoV-2; Tears - chemistry; Tonometry, Ocular - instrumentation; Young Adult
• ISSN: 1057-0829; 1536-481X
• DOI: 10.1097/IJG.0000000000001672

PURPOSE:To quantify aerosol and droplets generated during noncontact tonometry (NCT) and assess the spread distance of the same.
METHODOLOGY:This was an experimental study on healthy human volunteers (n=8 eyes). In an experimental setup, NCT was performed on eyes (n=8) of human volunteers under normal settings, with a single and 2 drops of lubricant. High-speed shadowgraphy, frontal lighting technique, and fluorescein analysis were used to detect the possible generation of any droplets and aerosols. Mathematical computation of the spread of the droplets was then performed.
RESULTS:In a natural setting, there was no droplet or aerosol production. Minimal splatter along with droplet ejection was observed when 1 drop of lubricant was used before NCT. When 2 drops of lubricant were instilled, a significant amount of fluid ejection in the form of a sheet that broke up into multiple droplets was observed. Some of these droplets traversed back to the tonometer. Droplets ranging from 100 to 500 µm in diameter were measured.
CONCLUSIONS:There was no droplet generation during NCT performed in a natural setting. However, NCT should be avoided in conditions with high-tear volume (natural or artificial) as it would lead to droplet spread and tactile contamination.