title: Thermal evaluation of two phacoemulsification systems.
abstract: OBJECTIVE
  To compare thermal profiles of new transversal ultrasound power modulation to torsional ultrasound in an artificial chamber and cadaver eye.
  
  
  METHODS
  Laboratory investigation.
  
  
  METHODS
  John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, was the study setting. Temperature increase after 30 seconds was measured at the needle midshaft in an artificial chamber and at maximal friction point in a cadaver eye. Ellips FX (transverse) was tested at 100% power, as was Signature with micropulse settings (6 milliseconds on and off). OZil (torsional only) was tested at 100% power in the artificial chamber and cadaver eye. Runs were completed with aspiration blocked. Temperature was continuously measured on the phacoemulsification sleeve using a microthermistor probe connected to the BAT-10 multipurpose thermometer, with an accuracy of ±0.1°C.
  
  
  RESULTS
  Transversal FX had a greater temperature increase than micropulse (p < 0.001) and torsional (p < 0.001). Micropulse had a greater temperature increase than torsional (p < 0.001). The cadaver eye had a greater temperature increase than the artificial chamber for torsional (p < 0.001).
  
  
  CONCLUSIONS
  Higher heat accumulation and potential for incisional burn occurred with the cadaver model than with the artificial chamber, suggesting the need for caution when using 100% torsional ultrasound with aspiration blocked. Transversal FX generated more heat than was reported originally. Further study is needed to determine the incidence of incisional burn with varied power settings for this new model. Micropulse generated more heat than previous reports, but the increased efficiency is likely to negate potentially increased incisional burn risk.
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Henriksen
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
authors.forename: Gareth
authors.initials: G
authors.lastname: Gardiner
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
authors.forename: Kevin
authors.initials: K
authors.lastname: Garff
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
authors.forename: Isha
authors.initials: I
authors.lastname: Gupta
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
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.
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.
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.
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. Electronic address: randallj.olson@hsc.utah.edu.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Olson
mesh_terms: D001831:Body Temperature; D002102:Cadaver; D002386:Cataract / Q000473:pathology; D019220:High-Energy Shock Waves; D006358:Hot Temperature; D006801:Humans; D007908:Lens, Crystalline / Q000601:surgery*; D008866:Microsurgery / Q000295:instrumentation; D008954:Models, Biological; D018918:Phacoemulsification / Q000295:instrumentation*; D013814:Thermal Conductivity; D013817:Thermography / Q000379:methods; D013821:Thermometers