Effect of bottle height and aspiration rate on postocclusion surge in Infiniti and Millennium peristaltic phacoemulsification machines.

PURPOSE

To assess how flow and bottle height affect postocclusion surge in the Infiniti (Alcon, Inc.) and Millennium (Bausch & Lomb) peristaltic machines.

SETTING

John A. Moran Eye Center Clinical Laboratories, University of Utah, Salt Lake City, Utah.

METHODS

Postocclusion anterior chamber depth changes were measured in human eye-bank eyes using A-scan. Surge was simulated by clamping the aspiration tubing and releasing it at maximum vacuum. In both machines, surge was measured (1) with aspiration held constant at 12 mL/min and bottle heights at 60, 120, and 180 cm and (2) with bottle height held constant at 60 cm and aspiration rates at 12, 24, and 36 mL/min.

RESULTS

Surge decreased approximately 40% with each 60 cm increase in bottle height in the Infiniti. It was constant at all bottle heights in the Millennium. At 12 and 24 mL/min aspiration rates, surge in the Millennium was less than half that in the Infiniti (P<.001).

CONCLUSIONS

Postocclusion surge decreased linearly with increasing bottle height in the Infiniti system and was relatively constant with increasing bottle height in the Millennium system. The Millennium may offer a more stable phacoemulsification platform with respect to surge at a higher aspiration rate.