In vitro analysis of clinically relevant aspects of a polymer-coated phacoemulsification tip vs a traditional tip

Abstract

Purpose: To compare the in vitro incisional temperature, acoustic energy, transient cavitation, and turbulence of the polymer-coated hybrid phacoemulsification tip with the balanced tip. Setting: Pasteur Ophthalmology Clinic, Vitacura, Santiago, Chile. Design: Laboratory study Methods: The Centurion Vision System with Active Sentry handpiece was used with tips operated in torsional mode, and stroke was normalized. For thermal measurements, controlled loads were applied over the tip sleeve simulating the pressure applied at the expected level of the corneal incision. Heat generated was recorded on a blackbody filmstrip using infrared imaging. A directional hydrophone provided 360° mapping of acoustic pressure. Cavitation patterns with increasing ultrasound power were imaged with high-speed video recording. Particle image velocimetry was used to evaluate turbulence, streaming, and bubble formation. Results: The temperature rise for the hybrid and balanced tips was lower than with the control mini-flared Kelman tip (P≤0.0001). The hybrid tip generated reduced acoustic output compared with the balanced tip. Ultrasound threshold for cavitation was higher for the hybrid versus balanced tip (55% vs 25%). Fluid turbulence was more evident with the balanced tip compared with the hybrid tip at all flow conditions when normalized for stroke at 60% and 80% power for balanced and hybrid tip, respectively. Conclusion: The polymer-coated hybrid tip showed reduced heat generation compared with the control mini-flared Kelman tip and had lower acoustic output, lower cavitation, and lower turbulence compared with the balanced tip, suggesting potential for improved clinical safety.