Effects on phacoemulsification efficiency and chatter at variable longitudinal ultrasound settings when combined with constant torsional energy.
Bohner Austin, Peterson John S, Wright Alex J, Mamalis Christina, Bernhisel Ashlie, Zaugg Brian, Barlow William R, Olson Randall J, Pettey Jeff H
AI Summary
This study found 60% longitudinal ultrasound power optimizes phacoemulsification efficiency while minimizing chatter, improving cataract surgery outcomes by balancing effectiveness and safety.
Abstract
Purpose
To evaluate longitudinal power settings for optimally efficient lens fragment removal, using the Centurion machine.
Setting
John A. Moran Eye Center, University of Utah, Salt Lake City, USA.
Design
Experimental study.
Methods
Porcine lens nuclei were cut into 2.0 mm cubes. Experiments were conducted at 100% torsional power; vacuum set at 500 mm Hg, aspiration 50 mL/min, and intraocular pressure 110 mm Hg. A 20-degree tip with a 30-degree bevel was used. Longitudinal power was tested between 20% and 100%. Efficiency (time for fragment removal) and chatter (the number of times the fragment bounced from the tip) were measured.
Results
A linear increase in efficiency was observed from 20% to 100% longitudinal power (R = 0.9281, slope = -0.0271). An efficiency slope change occurred at 60% power, with the largest incremental change in efficiency between 20% and 60% (R = 0.9756, slope = -0.0394) and a lesser change between 60% and 100% (R = 0.9827, slope = -0.0121). Chatter analysis showed minimal events at 20% to 60%, but a significant increase at >80% (P = .005). This increase appeared to be incremental (R = 0.8929).
Conclusions
Increasing longitudinal power, with all other settings constant, increased efficiency. Greatest efficiency gains were observed between 20% and 60%. At 80% and 100%, chatter events increased significantly. With a goal of recommending optimally efficient settings while minimizing excess energy and chatter, adding 60% of longitudinal power to 100% torsional power was shown to be the best setting to increase efficiency and avoid repulsion in these vacuum and aspiration settings.
MeSH Terms
Shields Classification
Key Concepts4
An experimental study using porcine lens nuclei found a linear increase in efficiency for lens fragment removal using the Centurion machine from 20% to 100% longitudinal power (R = 0.9281, slope = -0.0271) when combined with 100% torsional power, 500 mm Hg vacuum, 50 mL/min aspiration, and 110 mm Hg intraocular pressure.
In an experimental study using porcine lens nuclei and the Centurion machine, the largest incremental change in efficiency for lens fragment removal was observed between 20% and 60% longitudinal power (R = 0.9756, slope = -0.0394), compared to a lesser change between 60% and 100% longitudinal power (R = 0.9827, slope = -0.0121).
Chatter events during lens fragment removal using the Centurion machine showed minimal occurrences at 20% to 60% longitudinal power but a significant increase at >80% longitudinal power (P = .005) in an experimental study with porcine lens nuclei, while maintaining 100% torsional power, 500 mm Hg vacuum, 50 mL/min aspiration, and 110 mm Hg intraocular pressure.
Adding 60% longitudinal power to 100% torsional power, with vacuum set at 500 mm Hg, aspiration at 50 mL/min, and intraocular pressure at 110 mm Hg, was identified as the best setting to increase efficiency and avoid repulsion (chatter) for phacoemulsification using the Centurion machine in an experimental study with porcine lens nuclei.
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