Effect of increasing flow when grooving during phacoemulsification

Abstract

To determine optimum flow settings on the Centurion Vision System during the grooving step in cataract surgery. John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA. Experimental study. Intact porcine lenses hardened by formalin and placed in a chamber designed to simulate the anterior chamber of the eye were used to test flow rate settings at 20mL/min, 40mL/min, and 60mL/min. Vacuum was set at 400mm Hg, longitudinal power at 80%, torsional power at 80%, and intraocular pressure at 50mm Hg. A balanced phaco tip with a 20-degree tip and a 30-degree bevel was used. Efficiency (time to groove the lens in half) was determined. Increasing flow from 20 to 40mL/min during grooving increased efficiency by 17% (P=.05), with no significant improvement shown at 60mL/min. A flow rate of 40mL/min was determined to be most efficient during the grooving step of cataract surgery. Further increases in flow rate showed no statistically significant improvement in efficiency, and with only 17% improvement flow rates less than 40mL/min might be almost as efficient and might be safer.