The effect of increasing power when grooving using phacoemulsification

Abstract

Purpose: To determine optimal power settings on the Centurion Vision System during the grooving step in cataract surgery. 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 longitudinal power at 40%, 70%, and 100% and torsional power at 0%. Flow rate was set at 40 mL/min. Vacuum was set at 400 mmHg, intraocular pressure was set at 50 mmHg, and a balanced phacoemulsification 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 longitudinal power from 40% to 70% increased efficiency by 28% (P<0.05), and by 32% (P<0.05) when increasing longitudinal power from 40% to 100%. There was no statistically significant increase in efficiency from 70% to 100%. Conclusion: For the tested variables, a longitudinal power of 70% was determined to be most efficient during the grooving step of cataract surgery for equivalent 3–4+ nuclei. Further increases in power demonstrated no statistically significant improvement in efficiency.