title: Comparison of Vacuum and Aspiration on Phacoemulsification Efficiency and Chatter Using a Monitored Forced Infusion System.
abstract: OBJECTIVE
  To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency and chatter using a monitored forced infusion system.
  
  
  METHODS
  In vitro animal study.
  
  
  METHODS
  
  
  
  METHODS
  John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
  
  
  METHODS
  Formalin-soaked porcine lenses were divided into 2 mm cubes (tip diameter, 0.9 mm). Vacuum levels were tested at 200, 300, 400, and 500 mm Hg; aspiration rates at 20, 35, and 50 mL/min. Torsional power was set at 60% and intraocular pressure at 50 mm Hg.
  
  
  RESULTS
  Increasing vacuum increased efficiency regardless of aspiration rates (R(2) = 0.92; P = .0004). Increasing aspiration further increased efficiency when vacuum was at 400 and 500 mm Hg (P = .004 for 20 vs 35 mL/min, P = .0008 for 35 vs 50 mL/min). At 200 and 300 mm Hg, efficiency only improved when increasing aspiration to 35 mL/min (P < .0001 with 20 vs 35 + 50 mL/min). Chatter improved with increasing vacuum, up to 400 mm Hg (P = .003 for 200 vs 300 mm Hg and P = .045 for 300 vs 500 mm Hg). A similar trend of improved chatter was seen with increasing levels of aspiration.
  
  
  CONCLUSIONS
  Vacuum improved efficiency up to 500 mm Hg independent of flow. Flow has an additive effect on efficiency through 50 mL/min, when vacuum is at 400 mm Hg or higher, and only up to 35 mL/min at vacuums less than 400 mm Hg. Chatter correlated with both vacuum and flow such that increasing either parameter decreases chatter, up to 400 mm Hg with vacuum.
authors.affiliation: Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
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.
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.
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.
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: 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: 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: D000818:Animals; D002386:Cataract / Q000473:pathology; D004195:Disease Models, Animal; D019220:High-Energy Shock Waves; D007263:Infusions, Parenteral; D007429:Intraocular Pressure / Q000502:physiology; D007908:Lens, Crystalline / Q000601:surgery*; D008991:Monitoring, Physiologic; D018918:Phacoemulsification / Q000295:instrumentation / Q000379:methods*; D013396:Suction; D013552:Swine; D014618:Vacuum