When we perform hydro-delineation, we separate the dense endo-nucleus from the relatively soft epi-nucleus. This is helpful in multiple different cases such as a posterior polar cases and dense cataracts to give us a smaller endo-nucleus and provide a degree of barrier protection with the epi-nucleus. Removing the epi-nucleus can be done with either the phaco probe or the I/A probe and in this video we will show cases using both methods.
The epi-nuclear shell is soft and typically does not need much phaco power, if any, for aspiration. But the danger is that it is soft and thin and applying phaco energy can cause the metal phaco tip to go through this shell and inadvertently hit the posterior capsule. We can help avoid this by choosing appropriate phaco parameters.
Some surgeons use dedicated epi-nucleus settings on the phaco machine where the vacuum and flow are lower compared to a chop mode or quadrant removal mode. In addition, the phaco energy setting is quite low. I prefer to simply using the same phaco chop settings and then control the vacuum level with the foot-pedal. You should choose the method that feels best in your hands.
click below to learn various approaches to removing the epi-nucleus in cataract surgery: