Comparison of two popular nuclear disassembly techniques for cataract surgeons in training: divide and conquer versus stop and chop

Purpose: To compare two common phacoemulsification techniques in the learning curve phase, and their effect on ultrasound energy dissipation. Methods: One hundred and ten consecutive patients scheduled for cataract surgery with the same surgeon in training were prospectively enrolled. Study was divided in two parts. In the first one, 60 patients were stratified for cataract grade [nuclear opalescence (NO) grade 2-4] and divided in two groups receiving surgery with the divide-and-conquer technique (Group-1) and with the stop-and-chop technique (Group-2). In the second part, 50 patients were stratified according to cataract grade (NO2-6), and the surgeon had to choose one of the two techniques according to personal preference. The primary outcome was the cumulative dissipated energy (CDE). Results: Significant differences of CDE were observed between the NO3 and NO4 cataracts in Group-1. In Group-2, this difference was not significant, suggesting that with more advanced cataracts, the stop-and-chop technique allows less ultrasound use. In the second part of the study, the stop and chop was most frequently used for more advanced cataracts. When considering harder cataracts (NO5-NO6), patients receiving surgery with the divide-and-conquer technique had higher CDE values compared to stop and chop. Conclusions: Both divide-and-conquer and stop-and-chop techniques are efficient in the learning curve. Stop and chop dissipates less energy in harder nuclei. Once surgeons reach sufficient experience with both techniques, they should switch to a stop-and-chop technique, allowing lower levels of ultrasound energy.