title: Fluid dynamics and intraocular pressure using venturi phacoemulsification machine in dogs ex vivo.
abstract: OBJECTIVE
  To optimize fluid dynamics through measuring intraocular pressure (IOP) in a venturi phacoemulsification machine in dogs.
  
  
  METHODS
  In step I, flow and IOP of the test chamber were measured using a pressure transducer with the bottle height (BH) set at 50, 70, 100, and 120 cm and the vacuum from 30 to 450 mmHg. A 19-gauge phaco and a 0.3-mm irrigation/aspiration (I/A) handpiece were used. In step II, flow and IOP were measured in an enucleated canine eye with a 3.0- and a 3.2-mm clear corneal incision (CCI), respectively. IOP was measured using the pressure transducer at a 30-mmHg vacuum to allow corneal deformation, to define the fluidic parameters for preventing surge.
  
  
  RESULTS
  Flow was directly proportional to the BH and vacuum, whereas IOP was directly proportional to the BH and inversely to the vacuum. Flow with an I/A handpiece was significantly less than with a phaco handpiece, explaining why IOP with an I/A handpiece was significantly higher than with a phaco handpiece. With the I/A handpiece, vacuum parameters less than 450 mmHg did not result in corneal deformation. IOP with a 3.2-mm CCI was significantly lower than with a 3.0-mm CCI, with the 3.2-mm flow being greater than the 3.0-mm flow.
  
  
  CONCLUSIONS
  BH during the I/A stage could be reduced to avoid unnecessary stress on the canine eye when using a venturi system. Although phacoemulsification with a 3.2-mm CCI could induce lower IOP, a 3.0-mm CCI might lessen the irrigation flow stress on the eye.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea.
authors.forename: Seonmi
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea.
authors.forename: Sangwan
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea.
authors.forename: Hyunwoo
authors.initials: H
authors.lastname: Noh
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea.
authors.forename: Kangmoon
authors.initials: K
authors.lastname: Seo
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000503:physiopathology; D002386:Cataract / Q000662:veterinary; D004283:Dog Diseases / Q000503:physiopathology / Q000601:surgery*; D004285:Dogs; D007429:Intraocular Pressure / Q000502:physiology; D018918:Phacoemulsification / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*
keywords: anterior chamber stability; bottle height; canine; flow rate; surge; vacuum pressure