Trench-assisted stop-and-cut technique: superficial nucleus trench assists the occlusion-free chopping technique in cataract surgery

The chopping technique is appropriate for moderate-to-hard nuclei; however, it can be technically difficult to sustain an occlusion to hold an unsolid nucleus. Our stop-and-press technique, a modification of the stop-and-chop technique, can achieve complete chopping without occlusion. The only prerequisite is stabilization of the nucleus; nucleus occlusion using ultrasound (US) power is not essential. Mastering horizontal chopping is required in this technique; however, it carries the risk of capsular tears and zonule rupture. After the nucleus is cracked into 2 heminuclei and rotated by 90 degrees (as in the stop-and-chop technique), a superficial groove (trench) is created in the lower heminucleus. The chopper is inserted into the equator area through the trench underneath the capsulorhexis edge and moved horizontally from the periphery toward the US tip to split the nucleus without occlusion. The superficial trench on the heminucleus allows the nucleus to be safely divided, thereby enabling an occlusion-free chopping technique.