Impact of Varied Vacuum and Aspiration Rates on Phacoemulsification Efficiency in a Peristaltic System
Purpose
To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency.
Methods
Formalin-soaked porcine lenses were divided into 2mm cubes. 0.9mm, 30 degree beveled 20 degree bent tips were used with micropulse ultrasound (6ms on and 6ms off) and peristaltic flow system. Vacuum levels were tested at 200, 300, 400, and 500 mmHg; and aspiration rates were tested at 20, 35, and 50mL/min. Efficiency (time to lens removal) and chatter (number of lens fragment repulsions from the tip) were determined.
Results
Increasing vacuum increased efficiency only when going from 200 mmHg to higher vacuum levels. Increasing aspiration increased efficiency at all points measured (25 mL/min vs. 35 mL/min, P < .0001; 35 mL/min vs. 50 mL/min, P = .012; and 25 mL/min vs. 50 mL/min, P < .0001). Chatter increased at 200mmHg and decreased with increasing flow.
Conclusion
Vacuum improved efficiency only up to 300mmHg and was more dependent on increasing flow. Similarly, chatter only correlated with 200mmHg vacuum and was more correlated with flow.