Purpose: To evaluate the differences in phaco time and power required between the divide and conquer and phaco chop nucleofractis techniques.
Setting: Department of Ophthalmology, Central Middlesex Hospital, London, United Kingdom.
Methods: A retrospective pilot study of 125 patients was followed by a prospective randomized study of 117 patients comparing the phaco chop with divide and conquer techniques in terms of phaco time (minutes), phaco power (%), equivalent phaco time (calculated time required if 100% power had been used throughout), intraoperative and postoperative complications, and postoperative visual acuity.
Results: In the pilot study, mean phaco time in the phaco chop group was 1.4 minutes +/- 0.09 (SD) and in the divide and conquer group, 3.4 +/- 0.1 minutes (P <.0001). Mean equivalent phaco time was also less in the phaco chop group (0.39 +/- 0.03 minutes) than in the divide and conquer group (0.98 +/- 0.08 minutes) (P <.0001). In the prospective study, phaco chop required significantly less phaco time (1.2 +/- 0.1 minutes) than divide and conquer (2.4 +/- 0. 1 minutes) (P <.0001), less phaco power (25.3% +/- 1.2% versus 35.1% +/- 1.2%) (P <.0001), and less equivalent phaco time (0.29 +/- 0.02 minutes versus 0.84 +/- 0.05 minutes) (P <.0001). The operating time was shorter in the phaco chop group. There were no differences in complications and postoperative visual acuity.
Conclusion: This study showed a significant advantage of the phaco chop over the divide and conquer technique in phaco power and duration. Phaco chop also required less operative time and intraocular manipulation without an apparent increase in intraoperative or postoperative complications.