title: Torsional power study using CENTURION phacoemulsification technology.
abstract: BACKGROUND
  To evaluate the effect of varying levels of power on phacoemulsification efficiency using the CENTURION Vision System.
  
  
  METHODS
  Formalin-soaked porcine lenses were divided into 2-mm cubes; 0.9-mm, balanced tips were used. Torsional power levels were tested from 10% to 100% at 10% intervals. Vacuum was set to 550 mmHg, aspiration to 50 ml/min, and intraocular pressure at 50 mmHg. Efficiency (time to lens removal) and chatter (number of lens fragment repulsions from the tip) were determined.
  
  
  RESULTS
  Increasing torsional power up to 60% increased efficiency. This effect was linear from 30 to 60% power (R2= .90; P < 0.05). There were no significant differences in efficiency past 60%. Chatter was highest at 10% power and decreased linearly (R2= .87; P = 0.007) as power was increased up to 60% power, and chatter did not improve above this power level.
  
  
  CONCLUSIONS
  Power improved efficiency only up to a 60% power level, and then was negligible. Chatter correlated well with power up to the 60% level, so that as power was increased, chatter decreased. Because there are no additional benefits in efficiency past 60% power, and because chatter is minimal at 60% power, we recommend torsional ultrasound at 60% as the optimal power setting for using the CENTURION System for phacoemulsification.l.
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Jensen
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Dallas S
authors.initials: DS
authors.lastname: Shi
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Robinson
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Kramer
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Zaugg
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Stagg
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Jeff H
authors.initials: JH
authors.lastname: Pettey
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Barlow
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Olson
mesh_terms: D000818:Animals; D002386:Cataract / Q000209:etiology; D004195:Disease Models, Animal; D004322:Drainage / Q000379:methods; D007429:Intraocular Pressure / Q000502:physiology; D007908:Lens, Crystalline / Q000601:surgery; D018918:Phacoemulsification / Q000295:instrumentation* / Q000379:methods; D013552:Swine; D054159:Torsion, Mechanical; D014618:Vacuum
keywords: animal; cataract; cataract extraction; crystalline; lens; mechanical; models; torsion