Feasibility of sleeveless bimanual phacoemulsification with the Millennium microsurgical system

To assess the feasibility of sleeveless bimanual phacoemulsification using the Millennium Microsurgical System (Bausch and Lomb Surgical) by measuring wound temperature during phacoemulsification.

In vitro laboratory.

The Millennium system was used in 6 eye-bank eyes using pulse mode and 80-milllisecond and 160-millisecond phaco burst mode width intervals. Wound temperatures were measured, and the wounds were observed for thermal injury.

In pulse mode and the nonoccluded state at 100% power, the maximum temperature was 43.8 degrees C. In the occluded state at 30% power, the maximum temperature was 51.7 degrees C after 70 seconds of occlusion. In phaco burst mode with a 160-millisecond burst-width interval, the maximum temperature was 41.4 degrees C (nonoccluded at 100% power). At 80% power, the maximum temperature was 53.2 degrees C within 60 seconds of full aspiration occlusion with the footpedal fully depressed. With an 80-millisecond burst-width interval in the nonoccluded and occluded states (100% power, footpedal fully depressed for 3 minutes), there was no significant temperature rise. The maximum temperature was 33.6 degrees C in the nonoccluded state and 41.8 degrees C in the occluded state. In all instances, the corneal wound remained clear. No wound burn or contracture was noted.

The demonstrated temperature rises were under clinically unusual parameters. Phacoemulsification with a sleeveless needle through a small stab incision can be safely performed with the Millennium system using conventional phaco burst mode settings within certain parameters.