Purpose: To compare actual flow and the vacuum necessary to generate that flow for the Advanced Medical Optics Sovereign (Advanced Medical Optics, Santa Ana, California, USA) and the Alcon Legacy (Alcon, Fort Worth, Texas, USA) phacoemulsification machines.
Design: In vitro laboratory study.
Methods: Flow was collected and machine indicated vacuum noted from 12 ml/min to 40 ml/min in 2 ml/min steps (20-gauge). Nineteen and 20-gauge tips were also compared. Machine indicated vacuum was converted to actual tip vacuum.
Results: Legacy flow (102.4 +/- 3.8% of indicated) was significantly more than Sovereign (96.5 +/- 3.9%; P < .0001). 20-gauge flow was less than 19-gauge flow (96.1% vs 98.6% of indicated, P < .0001). Sovereign had less unoccluded vacuum (70.3 +/- 3.2 mm Hg) than Legacy (89.4 +/- 1.2 mm Hg) at 36 ml/min of flow (P < .0001 for 26 to 36 ml/min of flow).
Conclusion: There is unoccluded vacuum at the phaco tip of these systems at 14 ml/min, of flow and at 40 ml/min, this was 112.0 mm Hg for the Legacy.