With a dense, brunescent cataract the posterior aspect of the nucleus becomes tough and leathery. Traditional chopping methods usually are not sufficient to propagate the nucleus division through this posterior plate. While there are many methods for dealing with this tough posterior plate, my preferred technique is to get the chopper behind the posterior nucleus, then trap the nucleus between it and the phaco probe tip so that more force can be applied to split the nucleus. Using just the holding power of vacuum like in most cases of phaco chop will not allow chopping because the nucleus will fall off the tip as the vacuum seal is broken. There is not enough holding power with vacuum alone and this is why I like to trap the nucleus between the chopper and phaco tip so that more mechanical energy can be applied for a successful chop.
