Effect of increasing flow when grooving during phacoemulsification

Abstract

Purpose: To determine optimum flow settings on the Centurion Vision System during the grooving step in cataract surgery.

Setting: John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA.

Design: Experimental study.

Methods: 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 20 mL/min, 40 mL/min, and 60 mL/min. Vacuum was set at 400 mm Hg, longitudinal power at 80%, torsional power at 80%, and intraocular pressure at 50 mm 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.

Results: Increasing flow from 20 to 40 mL/min during grooving increased efficiency by 17% (P = .05), with no significant improvement shown at 60 mL/min.

Conclusions: A flow rate of 40 mL/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 40 mL/min might be almost as efficient and might be safer.