Eyeworld

JUNE/JULY 2020 | EYEWORLD | 25 N Contact Braga-Mele: rbragamele@rogers.com by Amrit Rai, MD, Robert Mele, Amandeep Rai, MD, Rosa Braga-Mele, MD OVD into the eye and proceeded with lon- gitudinal and torsional phacoemulsification independently. Again, no visible aerosols were produced, either with microscope or side filming views. The surgeon's hands remained dry the entire time, as did the microscope. Therefore, performing irrigation and aspira- tion at the start of the case is shown to effec- tively evacuate the anterior chamber volume. Furthermore, following formation of the anterior chamber with OVD, no trypan blue was seen to be aerosolized during phacoemul- sification. 2. For Experiment 2, we also injected trypan blue into the anterior chamber after creating corneal incisions to mimic "viral" aque- ous. We then displaced the "viral" aqueous humor with OVD prior to introducing our phacoemulsification probe. In this exper- iment, we did not perform irrigation and aspiration to start the case. The viscoelastic successfully displaced the "viral" aqueous out of the eye without creating any aero- sols. When the phacoemulsification probe was introduced into the eye, we did not see any aerosols created by the longitudinal and torsional phacoemulsification, as listed above and seen in the video. 3. Experiment 3 was used as a control to demonstrate that applying phacoemulsifi- cation to an open sky model does create a visible plume. Furthermore, trypan blue was visible on the surgeon's gloves in this case, while this did not occur in either Experiment 1 or Experiment 2. Discussion In our series of experiments, we demonstrate two methods of performing phacoemulsifi- cation in a human cadaveric eye without the With COVID-19 still a major concern in the U.S. and around the world, EyeWorld Cataract Editor Rosa Braga-Mele, MD, shared results from a study where a series of experiments were conducted to evaluate whether the phaco probe could generate aerosols, as the virus has been shown to be transmitted via aerosols (among other ways). In this article, Dr. Braga-Mele provides details of the study, the methods, and some of the results. C OVID-19 is a severe respiratory illness caused by the novel coronavi- rus SARS-CoV-2. The virus has been shown to be transmitted via fomites, droplets, and aerosols. 1–2 The SARS- CoV-2 virus has been isolated from conjunctival swabs of infected individ- uals. 3–4 There are concerns among ophthalmolo- gists regarding whether the rapid oscillations of the phacoemulsification probe could generate aerosols. To evaluate this concern, we set up a series of experiments. For each experiment, we used a human cadaveric eye, a 2.2-mm clear cor- neal incision, and a 2.2-mm phacoemulsification sleeve, utilizing a Centurion phacoemulsification machine (Alcon) and evaluating both longitu- dinal and torsional phacoemulsification modal- ities. At the beginning of each experiment, we filled the anterior chamber with trypan blue dye to simulate "viral" aqueous and allow for easy visualization. What we studied 1. For Experiment 1, after creating our corneal wounds and injecting trypan blue into the anterior chamber of a human cadaveric eye, we performed irrigation and aspiration of the anterior chamber fluid with a sleeved I/A tip. Theoretically, doing this for 6–10 seconds should be adequate to remove the volume of aqueous in the anterior chamber. Recorded video (youtu.be/epcDtNN-PkI) shows suc- cessful removal of the "viral" fluid without the creation of aerosols. Next, we injected Addressing phaco aerosolization concerns due to COVID-19: A human cadaveric eye with trypan blue continued on page 26 About the authors Department of Ophthalmology and Vision Sciences University of Toronto Toronto, Canada

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