Aerosol generation through phacoemulsification

Abstract

Purpose: To evaluate whether phacoemulsification is an aerosol-generating procedure in an ex vivo experimental model. Setting: Sussex Eye Hospital, Brighton, United Kingdom. Design: Experimental study. Methods: In this ex vivo study on 15 porcine eyes, an optical particle counter was used to measure particles of 10 µm and less using the cumulative mode based on the 6 in-built channel sizes. The 2 parts of the study were to: (1) assess the efficacy of the particle counter in the theater environment where there are dynamic changes in temperature and humidity; and (2) to measure aerosol generation with 3 phacoemulsification settings: (i) continuous power with 80% longitudinal (5 eyes); (ii) continuous power with 100% torsional (5 eyes); and (iii) continuous power with 80% longitudinal with application of hydroxypropyl methylcellulose (HPMC) on the ocular surface (5 eyes). Five measurements were taken prephacoemulsification and 5 during phacoemulsification per eye therefore totaling 75 measurements. Results: Maximum aerosols were captured when the counter faced the aerosol source. There was no significant difference in aerosol generation of all sizes during each phacoemulsification setting with torsional, longitudinal, and longitudinal with HPMC (P > .01). Combining data of all 3 phacoemulsification settings (150 measurements from 15 eyes), there was no significant difference comparing prephacoemulsification and during phacoemulsification for aerosols of 5 µm or less (1455 vs 1363.85, P = .60), more than 5 to 10 μm (1.5 vs 1.03, P = .43), and of 10 µm or less (1209 vs 1131.55, P = .60). Conclusions: Phacoemulsification did not generate aerosols of 10 μm or less with continuous power using 80% longitudinal, 100% torsional, and 80% longitudinal setting with HPMC on the surface.

Vitrectomy as an Aerosol-Generating Procedure in the Time of COVID-19

“…To our knowledge, this is the first study to quantify aerosols and droplets levels generated during human vitrectomy surgery in real-world conditions. The results of all 3 experiments are consistent with previous ex vivo vitrectomy and phacoemulsification studies 4 , 5 , 7 demonstrating that although the vitrectomy cutter is a high-speed device, surgery using valved ports is unlikely to generate significant aerosolization. However, when used in open-air conditions inside a gallipot, a vitrectomy cutter may cause a slight increase in particle concentration.…”

Presence of SARS-CoV-2 Viral RNA in Aqueous Humor of Asymptomatic Individuals

“…Considering that millions of cataract surgeries are performed in the world each year, these findings carry potential implications for this elective surgery. Assessment of aerosolization during phacoemulsification in ex vivo models suggest that potential spread through the air is likely negligible 10 , 11 but may be dependent on incision size. 12 It is encouraging that there are no known cases of transmission during cataract surgery to date.…”

Novel Insights into the Transmission of SARS-CoV-2 Through the Ocular Surface and its Detection in Tears and Conjunctival Secretions: A Review

“…Aerosol generation has been evaluated during phacoemulsification and suggestions have been made to minimize visible aerosol production by using a 2.2-mm phacoemulsification tip and reapplying hydroxypropyl methylcellulose (HPMC) coating of the cornea every minute during phacoemulsification [ 38 ]. Another study revealed that phacoemulsification did not generate aerosols of 10 μm or smaller with continuous power using 80% longitudinal, 100% torsional, or 80% longitudinal setting with HPMC on the surface [ 39 ]. Visible aerosol generation during vitrectomy surgery has been also evaluated using a physical model, although this study did not find evidence of visible aerosol generation during simulated vitrectomy surgery [ 40 ].…”