The original technique of phaco chop involved placing the chopper under the capsulorhexis edge and then around the lens equator. This horizontal chop technique works very well but it does require careful placement of the chopper under the capsulorhexis and then placement around the cataract equator which is often not directly visible due to the iris. For surgeons who wish to learn phaco chop, this can be intimidating. Vertical chop is placing both instruments in the central nucleus and then propagating the crack from anterior to posterior. We can combine the best of both of these techniques to come up with a combo chop.
The phaco tip is embedded in the nucleus, just inside the sub-incisional capsulorhexis and the chopper is simply pushed into the nucleus opposite it, but still inside the capsulorhexis edge. The chopper is then brought towards the phaco tip, similar to horizontal chop, and then the crack is propagated from anterior to posterior, just like with vertical chop. This video shows the technique in detail, including slow motion analysis.
