Purpose: To compare the efficiencies of the operative procedures and the reductions in postoperative corneal endothelial cell density (ECD) after cataract surgery using 2 different phacoemulsification tips and their associated cassettes and tubing.
Setting: Wolfe Clinic, Marshalltown, Iowa, USA.
Methods: A randomized prospective study of 100 consecutive cases was conducted. All patients were adults having phacoemulsification using a hybrid in situ fracture technique. All cases were performed by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine. One of 2 45 degree phacoemulsification tips and associated cassettes and tubing were used: the 1.1 mm TurboSonics with normal tubing (n = 47) or the 0.9 mm Aspiration Bypass System (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 milliliters of balanced salt solution (BSS) used. Corneal ECD was determined preoperatively and 10 weeks postoperatively. An independent statistician performed 2-sample t tests or Wilcoxon rank sum tests on the data.
Results: There were no cases of anterior radial capsule tear, posterior capsule tear, vitreous loss, iris aspiration, incision leak, or suture closure. There was no correlation between amount of corneal ECD loss and any operative variable measured. Similar measurements for the 1.1 mm TurboSonics and the 0.9 mm ABS included, respectively, ECD loss 7.34% and 8.22%; metered phacoemulsification time 1.29 and 1.22 minutes; total time of the phacoemulsification process 113 and 105 seconds. There were statistically significant differences between the 1.1 mm TurboSonics tip and 0.9 mm ABS tip performance in mean power percentage overall (52% versus 48%) and overall BSS volume used (85 versus 76 mL).
Conclusions: The 0.9 mm ABS phacoemulsification tip used with the high-vacuum cassette and tubing provided the physical advantages of tip-size reduction while requiring similar ultrasonic power and BSS volumes as the 1.1 mm TurboSonics tip with standard cassette and tubing. Together, they provide a wider available dynamic range in which to integrate ultrasonic power, higher vacuum, and higher aspiration flow rates to improve the efficiency and ease of use than the standard 1.1 mm TurboSonics cataract operation.