The original phaco chop technique described by Dr. Nagahara in 1995 was the horizontal chop. This involves holding the lens nucleus with the phaco probe on high vacuum while placing the chopping instrument around the lens equator. Now, in a horizontal motion parallel to the iris, the chopper is brought toward the phaco tip and then the two instruments are moved apart laterally to propagate a full split of the nucleus.
This technique is safe and efficient and it allows for less ultrasonic energy to disassemble the nucleus compared to the older divide-and-conquer technique. You really must learn this technique, even if you intend to primarily use another method for phaco surgery. A good surgeon should master many techniques so that he may choose the one that best suits the patient and the clinical situation. Do not be stuck with doing just one technique, such as divide-and-conquer, for the rest of your career.
Here are a few keys for successful horizontal phaco chop:
- make a sufficiently large capsulorhexis of between 5.0 and 5.5 mm in diameter
- choose a cataract with sufficient density and nuclear sclerosis of at least 2+
- for phaco settings, choose a high vacuum setting to have greater holding power
- embed the phaco probe just inside the sub-incisional capsulorhexis and aim it towards the optic nerve (for temporal incisions)
- briefly deliver a burst of phaco power (foot position 3) to embed the phaco probe tip and then lift the foot pedal to position 2 (just vacuum) to hold the nucleus
- ensure that the chopper goes underneath the opposite edge of the capsulorhexis
- hook the lens equator with the chopper
- bring the chopper toward the phaco tip while holding the phaco probe still
- just before the chopper touches the phaco tip, move the two instruments (phaco probe and chopper) in opposite lateral directions to split the nucleus
- ensure that the nucleus is split fully into two halves by separating the hemi-nuclear pieces
- rotate the nucleus and further sub-chop, or just emulsify the two halves
Click below to learn the important Horizontal Phaco Chop Technique: