Performance comparison of the Alcon Legacy 20000 1.1 mm TurboSonics and 0.9 mm Aspiration Bypass System tips

Purpose: To compare the efficiencies of the operative procedures and the re ductions in postoperative corneal endothelial cell density (ECD) after cata ract surgery using 2 different phacoemulsification tips and their associate d cassettes and tubing. Setting: Wolfe Clinic Marshalltown, Iowa, USA. Methods: A randomized prospective study of 100 consecutive cases was conduc ted. All patients were adults having phacoemulsification using a hybrid in situ fracture technique. All cases were performed by 1 surgeon using the Al con Legacy 20000 phacoemulsification machine. One of 2 45 degree phacoemuls ification tips and associated cassettes and tubing were used: the 1.1 mm Tu rboSonics with normal tubing (n = 47) or the 0.9 mm Aspiration Bypass Syste m (ABS) tip with high-vacuum cassettes and tubing (n = 53). Measurements at the time of surgery included metered phacoemulsification time, percentage power used, total time spent in the phacoemulsification process, and millil iters of balanced salt solution (BSS(R)) used. Corneal ECD was determined p reoperatively and 10 weeks postoperatively. An independent statistician per formed 2-sample t tests or Wilcoxon rank sum tests on the data. Results: There were no cases of anterior radial capsule tear, posterior cap sule tear, vitreous loss, iris aspiration, incision leak, or suture closure . There was no correlation between amount of corneal ECD loss and any opera tive variable measured. Similar measurements for the 1.1 mm TurboSonics and the 0.9 mm ABS included, respectively, ECP loss 7.34% and 8.22%; metered p hacoemulsification time 1.29 and 1.22 minutes; total time of the phacoemuls ification process 113 and 105 seconds. There were statistically significant differences between the 1.1 mm TurboSonics tip and 0.9 mm ABS tip performa nce in mean power percentage overall (52% versus 48%) and overall BSS volum e used (85 versus 76 mt). Conclusions: The 0.9 mm ABS phacoemulsification tip used with the high-vacu um cassette and tubing provided the physical advantages of lip-size reducti on while requiring similar ultrasonic power and BSS volumes as the 1.1 mm T urboSonics tip with standard cassette and tubing. Together, they provide a wider available dynamic range in which to integrate ultrasonic power, highe r vacuum, and higher aspiration flow rates to improve the efficiency and ea se of use than the standard 1.1 mm TurboSonics cataract operation. (C) 1999 ASCRS and ESCRS.