From the Department of Cornea and Refractive Surgery, Narayana Nethralaya (Khamar, Shetty, Balakrishnan), Department of Mechanical Engineering, Indian Institute of Science (Kabi, Roy, Basu), and Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation (Sinha Roy), Bangalore, India.
J Cataract Refract Surg. 2020 Oct;46(10):1416-1421. doi: 10.1097/j.jcrs.0000000000000326.
To quantify the atomization of liquid over the cornea during flap creation using microkeratome using high-speed shadowgraphy.
Laboratory study.
Laboratory investigational study.
In an experimental setup, flap creation was performed on enucleated goat's eyes (n = 8) mounted on a stand using One Use-Plus SBK Moria microkeratome (Moria SA) to assess the spread of aerosols and droplets using high-speed shadowgraphy. Two conditions were computed. A constant airflow assumed uniform air velocity throughout the room. A decaying jet assumed that local air velocity at the site of measurements was smaller than the exit velocity from the air duct.
With the advancement of the microkeratome across the wet corneal surface, the atomization of a balanced salt solution was recorded on shadowgraphy. The minimum droplet size was ∼90 μm. The maximum distance traversed was ∼1.8 m and ∼1.3 m assuming a constant airflow (setting of refractive surgery theater) and decaying jet condition (setting of an operating theater with air-handling unit), respectively.
The microkeratome-assisted LASIK flap creation seemed to cause spread of droplets. The droplet diameters and velocities did not permit the formation of aerosols. Therefore, the risk of transmission of the virus to the surgeon and surgical personnel due to the microkeratome procedure seemed to be low.
使用高速阴影法定量测量微型角膜刀制作瓣时液体在角膜上的雾化情况。
实验室研究。
实验室研究。
在实验装置中，使用 One Use-Plus SBK Moria 微型角膜刀（Moria SA）在支架上对去核山羊眼（n = 8）进行瓣制作，使用高速阴影法评估使用高速阴影法评估气溶胶和液滴的扩散情况。计算了两种情况。假定恒定气流在整个房间内保持均匀的空气速度。衰减射流假设在测量点的局部空气速度小于空气导管的出口速度。
随着微型角膜刀在湿润的角膜表面上的推进，在阴影图上记录了平衡盐溶液的雾化情况。最小液滴尺寸约为 90μm。最大距离分别为约 1.8 米和约 1.3 米，分别假设为恒定气流（屈光手术手术室设置）和衰减射流条件（带空气处理单元的手术室设置）。
微型角膜刀辅助 LASIK 瓣制作似乎会导致液滴扩散。液滴直径和速度不允许形成气溶胶。因此，由于微型角膜刀手术，病毒传播给外科医生和手术人员的风险似乎较低。
