Legacy AdvanTec and Sovereign WhiteStar: A wound temperature study

Abstract

Purpose: To assess the wound temperature of the Sovereign® WhiteStar (S-WS) (AMO) and Legacy® AdvanTec® (L-ADV) (Alcon) phacoemulsification systems. Setting: John A. Moran Eye Center, Health Sciences Center, University of Utah, Salt Lake City, Utah, USA. Methods: Phacoemulsification using 20-gauge, 30-degree straight tips with the L-ADV and S-WS systems was performed in fresh cadaver eyes. The power was set at 50%, and aspiration was 12 mL/min; the L-ADV was run at 15 pulses per second (pps) and the S-WS at WS CF (6 milliseconds on, 12 milliseconds off). Temperature was measured at 5-second intervals for 60 seconds using a microthermistor placed in the wound. The phaco tip was angled 30 degrees to increase wound-tissue contact. At 10 seconds, the flow was clamped to simulate occlusion. Five runs, sleeved and unsleeved, were averaged for the phaco tip. Results: The mean temperature was significantly higher with L-ADV than with S-WS (from 10 seconds on in the sleeved condition and from 5 seconds on in the unsleeved condition after the aspiration line was clamped). In 2 of 5 sleeved runs and 4 of 5 unsleeved runs, the L-ADV handpiece decreased power as the temperature increased. One run with the L-ADV with sleeve showed signs of wound burn. There were no signs of wound burn with the S-WS. The highest temperature recorded was 57.5°C with the L-ADV and 38.6°C with the S-WS. Power tests showed L-ADV protected the stroke length and S-WS had constant power except in air where it increased power. Conclusions: There was less increase in wound temperature over time with the S-WS than with the L-ADV system in sleeved and unsleeved simulated surgery in human eye-bank eyes. Because the ultrasound handpieces respond differently under different load scenarios, meaningful comparisons of pulsing features are difficult to create.