When performing classic phaco chop, we use the vacuum holding power of the phaco probe to fixate the nucleus while the chopper splits it. This works very well for most cataracts where the 400-500 mmHg of vacuum holding power is enough, but when the nucleus is very dense the force of the chopper can break the occlusion at the phaco tip and the purchase on the nucleus is lost. This becomes like trying to cut a piece of meat with just a knife and no fork to stabilize it. Our guest surgeon does technique where a central trench is made in the nucleus, similar to the phaco pit technique, the rotary chop method, and the submarine chop. This allows the nucleus to become trapped between the phaco tip and the chopper so that mechanical force can be used to split the nucleus without relying on the vacuum holding power. This method is great for the dense brunescent cataract shown in this video. Beautiful surgery.
