The Effect of Pulsing on Transverse Ultrasound Efficiency and Chatter.

PURPOSE

To evaluate the effects of micropulse, long pulse, and continuous ultrasound on transverse ultrasound using Abbott Medical Optics' (AMO) WhiteStar Signature Pro with the Ellips FX handpiece.

DESIGN

In vitro laboratory study.

METHODS

This study was conducted at the John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA. Porcine lenses were hardened in formalin for 2 hours and equilibrated in basic salt solution (BSS) over a 24-hour period. The lenses were then cubed in 2.0 × 2.0-mm pieces. These pieces were stored in BSS until the time of experimentation. The AMO WhiteStar Signature Pro machine (Abbott Medical Optics) with the Ellips FX handpiece and a 0.9-mm bent Dewey tip with a 30-degree bevel (Microsurgical Technology Inc) were used for phacoemulsification. Three runs of 20 lenses each were performed, measuring efficiency and chatter. Transverse ultrasound varied in the 3 runs and included continuous, 6 ms on/off micropulse, and 50 ms on/off long pulse.

RESULTS

Micropulse was more efficient than long pulse by 43% (P = .00003) and continuous by 42% (P = .000387). There were also less chatter events with micropulse than with long-pulse and continuous ultrasound. However, this difference did not reach significance.

CONCLUSION

The 6 ms on and 6 ms off micropulse transverse 3-dimensional ultrasound is more efficient and produces fewer chatter events than both long-pulse and continuous ultrasound.