title: Intraocular pressure study using monitored forced-infusion system phacoemulsification technology.
abstract: To optimize phacoemulsification efficiency by varying the intraocular pressure (IOP) using the Centurion Vision System, a monitored forced-infusion system.
  
  
  
  John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.
  
  
  
  Laboratory investigation.
  
  
  
  Porcine lenses were soaked in formalin and divided into 2.0 mm cubes; 0.9 mm balanced tips were used. Intraocular pressure levels were tested from 30 to 110 mm Hg at 10 mm Hg intervals. Vacuum was set at 500 mm Hg, aspiration at 35 mL/min, and torsional power at 60%. Efficiency (time to lens removal) and chatter (number of lens fragment repulsions from the tip) were measured.
  
  
  
  There was a linear relationship between efficiency and IOP. Increasing IOP led to an increase in efficiency (ie, to a decrease in time necessary to remove the lens fragment) (R(2) = .5769, P = .0176). Chatter correlated with IOP in the range of 30 to 50 mm Hg (R(2) = .4506, P = .0448) and was minimal at higher IOPs.
  
  
  
  Increasing IOP in the monitored forced-infusion system improved efficiency. Chatter was also decreased or eliminated with increasing IOP. Additional studies will be required to understand the reasons for these findings.
  
  
  
  None of the authors has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Jensen
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Boulter
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA.
authors.forename: Nathan G
authors.initials: NG
authors.lastname: Lambert
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Zaugg
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Stagg
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA.
authors.forename: Jeff H
authors.initials: JH
authors.lastname: Pettey
authors.affiliation: From the Department of Ophthalmology (Jensen, Lambert, Zaugg, Stagg, Pettey, Olson), John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, and the Department of Ophthalmology (Boulter), Texas A & M University, College Station, Texas, USA. Electronic address: randallj.olson@hsc.utah.edu.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Olson
mesh_terms: D000818:Animals; D007429:Intraocular Pressure; D007908:Lens, Crystalline; D018918:Phacoemulsification / Q000379:methods*; D013552:Swine; D014065:Tonometry, Ocular