Phaco Fundamentals Part 9: Longitudinal & Torsional Ultrasound

Ultrasonic vibrations are traditionally delivered in a forward-and-back longitudinal manner. We can also deliver these vibrations is a circular manner and these often go by names of torsional, elliptical, or other descriptors. During ultrasound delivery, we can adjust the amount of each type of energy given to come up with a balance that is ideal for our step of surgery, the technique, and the type of cataract.

While all phaco machines will have longitudinal ultrasound energy delivery, only the newer models from some companies will have the other forms such as torsional. Remember that a great surgeon can operate with any machine, and even if you give me a 20 year old phaco machine, I will adapt my technique to the limitations and still deliver an excellent outcome. You can do the same.

The longitudinal energy can be delivered as continuous, pulse, or burst. And we have previously explained all of that in our phaco fundamentals series. In this video we show you how to adjust pulse mode parameters (power levels, pulse rate, and time on duty cycle) and burst mode parameters (power levels, the burst width on time, and the rest interval off time). We can also mix longitudinal with torsional energy.

If you have a different phaco machine than I’m using in this video, do not worry. The ideas and concepts are the same. You can learn your phaco machine and adapt the settings.

Click below to learn how to set up longitudinal and torsional ultrasound:


  1. Our Alcon rep is insisting that using torsional energy is better than longitudinal because it is more efficient and uses less energy for making a grove but in my hands it feels less controlled with increased torsional energy.

    1. sounds like your rep is an expert at sales but not at physics. ask this rep how many cataract surgeries he/she has done. then you decide what works best in your hands.

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