Comparison of Nagahara phaco-chop and stop-and-chop phacoemulsification nucleotomy techniques

Purpose: To compare intraoperative and postoperative effects of Nagahara phaco-chop and stop-and-chop phacoemulsification nucleotomy techniques. Setting: Department of Ophthalmology, SBMU First Aid and Traumatology Hospital, Ankara, Turkey. Methods: Seventy patients were evaluated prospectively in 2 groups. The Nagahara phaco-chop nucleotomy technique was performed in Group 1 (35 eyes) and the stop-and-chop technique in Group 2 (35 eyes). There were no significant between-group differences. The mean phaco time, phaco power, effective phaco time, time to achieve maximum vision, corneal thickness increase relative to the preoperative values, and time to return to the preoperative values were determined. All parameters in both groups were statistically compared using the chi-square test and the independent-samples t test. Results: The mean phaco time was 1.3 minutes +/- 0.7 (SD), phaco power was 16.7% +/- 5.0%, and effective phaco time was 14.9 +/- 11.8 seconds in Group 1 and 1.8 +/- 0.9 minutes, 20.0% +/- 6.2%, and 22.3 +/- 14.2 seconds, respectively, in Group 2. The mean time to achieve maximum vision postoperatively was 6.9 +/- 3.7 days in Group 1 and 11.7 +/- 7.7 days in Group 2. The mean postoperative corneal thickness increase in Group 1 and Group 2 was 52.3 +/- 84.5 mum and 111.6 +/- 151.2 mum, respectively, and the mean time to return to preoperative pachymetry values, 9.8 +/- 5.7 days and 13.7 +/- 10.0 days, respectively. There were significant between-group differences in these parameters. Conclusions: The Nagahara. phaco-chop technique had fewer negative effects on the corneal endothelium as less ultrasonic energy was used. This accelerated the functional healing process and the return to preoperative physiologic values. (C) 2004 ASCPS and ESCRS.