Propensity and quantification of aerosol and droplet creation during phacoemulsification with high-speed shadowgraphy amid COVID-19 pandemic

Abstract

Purpose: To study propensity of aerosol and droplet generation during phacoemulsification using high-speed shadowgraphy and quantify its spread amid COVID-19 pandemic. Setting: Aerosol and droplet quantification laboratory. Design: Laboratory study. Methods: In an experimental set-up, phacoemulsification was performed on enucleated goat eyes and cadaveric human corneoscleral rims mounted on an artificial anterior chamber. Standard settings for sculpt and quadrant removal mode were used on Visalis 100 (Carl Zeiss Meditec AG). Microincision and standard phacoemulsification were performed using titanium straight tips (2.2 mm and 2.8 mm in diameter). The main wound incisions were titrated equal to and larger than the sleeve size. High-speed shadowgraphy technique was used to detect the possible generation of any droplets and aerosols. The visualization and quantification of size of the aerosols and droplets along with calculation of their spread were the main outcome measures. Results: In longitudinal phacoemulsification using a peristaltic pump device with a straight tip, no aerosol generation was seen in a closed chamber. In larger wounds, there was a slow leak at the main wound. The atomization of balanced salt solution was observed only when the phacoemulsification tip was completely exposed next to the ocular surface. Under this condition, the nominal size of the droplet was approximately 50 µm, and the maximum calculated spread was 1.3 m. Conclusions: There was no visible aerosol generation during microincision or standard phacoemulsification. Phacoemulsification is safe to perform in the COVID-19 era by taking adequate precautions against other modes of transmission.

Novel device to contain aerosols during phacoemulsification

“…But this study did not include particles of size less than 20 microns and invisible aerosols into consideration. [ 4 ] It is understood that even high-resolution cameras can detect only particles of size more than 10 microns. [ 3 ] But, the SARS-CoV-2 aerosols were mainly found to include two size ranges, one in the sub-micrometer region (dp between 0.25 and 1.0 µm) and the other in super micrometer region (dp >2.5 µm).…”

“…[ 2 3 ] Some studies have demonstrated aerosol formation, while other studies provide contradictory data. [ 4 ] The latter have not commented about the visualisation of particles of size less than 20 microns.…”

Moorfields cataract surgery recovery pilot during the Covid-19 pandemic

“…Surgical staff wore appropriate personal protective equipment. Techniques shown to reduce aerosolisation were utilised where possible during phacoemulsification: use of 2.2-mm phaco tip [1], hydroxypropyl methylcellulose application on corneal incision [1], tip placement away from corneal incision [4], in addition to routine use of povidoneiodine for cleaning and complete viscoelastic exchange of anterior chamber fluid before capsulorrhexis. Theatre floors were disinfected between cases and all surgery performed under local anaesthesia.…”

Aerosolization and Fluid Spillage During Phacoemulsification in Human Subjects

“…9 Other groups have also demonstrated similar findings in porcine eyes and goat eyes mounted with human cadaveric corneoscleral rim. [10][11][12] However, these studies were all conducted in a simulated setting, while confirmatory studies of phacoemulsification in real-world settings have yet to be conducted. The living human cornea biomechanics also differs from plastic model eyes and cadaveric eyes.…”