University of Arizona College of Medicine, Phoenix, AZ.
Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT.
Can J Ophthalmol. 2019 Jun;54(3):395-398. doi: 10.1016/j.jcjo.2018.07.005. Epub 2018 Sep 11.
To evaluate the optimum percent on time for the most efficient lens fragment removal using long-pulse torsional ultrasound (US).
In vitro laboratory study.
Porcine lens nuclei were incubated in formalin for 2 hours and then cut into 2 mm cubes. Phacoemulsification was performed using the Centurion Vision System and Infiniti OZil handpiece with the balanced tip. Vacuum was set at 500 mm Hg, aspiration rate at 50 mL/min, and intraocular pressure (IOP) at 50 mm Hg. Pulse rate was 26 pulses/second. Studied parameters were percent power: 60%, 80%, and 100%, and percent on times: 50%, 60%, 70%, and 80%. Efficiency was the total time for a cube to be emulsified. Chatter was the number of times the lens fragment bounced off the tip.
There was no significant difference in efficiency between 50%, 60%, and 70 % on-time settings (p = 0.17 and 0.08, respectively); however, there was significant increase in efficiency when the on time was increased from 70% to 80% (p = 0.03). Increasing power from 60% to 100% showed a statistically significant efficiency increase (p = 0.001). There was no significant change in chatter with increasing on time; however, there was a statistically significant increase in chatter with every power level increase.
Increasing on-time percent does not improve efficiency under torsional long-pulse US. There is no significant change in chatter with increasing on-time percent. Increasing power increases efficiency despite chatter increase. Long-pulse US does not appear to influence torsional action in a clinically meaningful way.
评估使用长脉冲扭转超声（US）进行最有效晶状体碎片清除的最佳时间百分比。
体外实验室研究。
将猪晶状体核在福马林中孵育 2 小时，然后切成 2 毫米的立方体。使用 Centurion Vision 系统和 Infiniti OZil 手持件及平衡尖端进行超声乳化。设置真空度为 500mmHg，抽吸率为 50mL/min，眼内压（IOP）为 50mmHg。脉冲率为 26 脉冲/秒。研究的参数为功率百分比：60%、80%和 100%，以及时间百分比：50%、60%、70%和 80%。效率是指一个立方体乳化的总时间。喋喋不休是指晶状体碎片从尖端弹回的次数。
在 50%、60%和 70%时间设置下，效率没有显著差异（p=0.17 和 0.08）；然而，当时间从 70%增加到 80%时，效率显著增加（p=0.03）。从 60%增加到 100%功率显示出统计学上的效率增加（p=0.001）。随着时间的增加，喋喋不休没有显著变化；然而，随着每个功率水平的增加，喋喋不休显著增加。
在扭转长脉冲 US 下，增加时间百分比并不能提高效率。随着时间百分比的增加，喋喋不休没有明显变化。尽管喋喋不休增加，但增加功率会提高效率。长脉冲 US 似乎不会以有意义的方式影响扭转作用。
