From the Department of Cataract Surgery (N. Shetty, Kaweri), Department of Cornea and Refractive Surgery (Khamar, Balakrishnan, R. Shetty), Narayana Nethralaya, Department of Mechanical Engineering, Indian Institute of Science (Rasheed, Kabi, Basu), Bangalore, India; University Eye Clinic, Maastricht University Medical Center (Nuijts), Maastricht, the Netherlands; Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation (Sinha Roy), Bangalore, India.
J Cataract Refract Surg. 2020 Sep;46(9):1297-1301. doi: 10.1097/j.jcrs.0000000000000289.
To study propensity of aerosol and droplet generation during phacoemulsification using high-speed shadowgraphy and quantify its spread amid COVID-19 pandemic.
Aerosol and droplet quantification laboratory.
Laboratory study.
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.
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.
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.
使用高速阴影摄影术研究超声乳化过程中气溶胶和液滴的产生倾向，并在 COVID-19 大流行期间量化其传播范围。
气溶胶和液滴定量实验室。
实验室研究。
在实验装置中，对去核山羊眼和安装在人工前房上的尸体人角膜缘进行超声乳化。在 Visalis 100（卡尔蔡司医疗技术公司）上使用雕刻和象限去除模式的标准设置。使用钛直型尖端（直径 2.2 毫米和 2.8 毫米）进行微切口和标准超声乳化。主伤口切口等于或大于套管尺寸。使用高速阴影摄影术技术检测可能产生的任何液滴和气溶胶。可视化和量化气溶胶和液滴的大小以及计算它们的传播是主要的测量结果。
在使用蠕动泵装置和直型尖端进行的纵向超声乳化中，在封闭的室内未观察到气溶胶的产生。在较大的伤口中，主伤口处有缓慢泄漏。只有当超声乳化尖端完全暴露在眼表面旁边时，才观察到平衡盐溶液的雾化。在此条件下，液滴的标称尺寸约为 50 µm，最大计算传播距离为 1.3 m。
在微切口或标准超声乳化期间没有观察到可见的气溶胶产生。通过采取充分的预防措施来防止其他传播模式，在 COVID-19 时代进行超声乳化是安全的。
