title: Visualization of irrigation fluid flow and calculation of its velocity distribution in the anterior chamber by particle image velocimetry.
abstract: OBJECTIVE
  To visualize irrigation fluid flow and calculate its velocity distribution in the anterior chamber during phacoemulsification by particle image velocimetry.
  
  
  METHODS
  Porcine eyes were fixed in a glass chamber filled with balanced salt solution. An ultrasound handpiece was fixed to the glass chamber, and its tip was inserted into the anterior chamber through a corneal incision. Irrigation fluid was mixed with fluorescein-labeled liposomes as tracer particles. During phacoemulsification without ultrasound, a sheet-like Nd-YAG pulsed laser beam was emitted and moved from the iris plane to the top of the cornea continuously. Images of illuminated liposomes in the anterior chamber were captured at short intervals with a CCD camera, and the velocity distribution of irrigation fluid flow was calculated by particle image velocimetry.
  
  
  RESULTS
  By particle image velocimetry, the flow velocity distribution could be calculated in any plane of the anterior chamber. Dynamic flow of the irrigation fluid, ejected from the tip of the ultrasound handpiece and returned to an aspiration port, was visualized clearly in the anterior chamber. The maximum flow velocity in the anterior chamber was 342 ± 131 mm/s.
  
  
  CONCLUSIONS
  Particle image velocimetry enabled the visualization of irrigation fluid flow and quantification of its velocity distribution in different planes of the anterior chamber during cataract surgery. These data are essential for evaluating the safety and efficacy of new surgical settings and devices during phacoemulsification.
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan. kajiyuichi@hotmail.com
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kaji
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamashita
authors.forename: Jun
authors.initials: J
authors.lastname: Sakakibara
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Oshika
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism*; D004338:Drug Combinations; D005456:Fluorescent Dyes; D057446:Hydrodynamics; D008081:Liposomes; D008903:Minerals / Q000378:metabolism*; D008954:Models, Biological; D009883:Ophthalmic Solutions / Q000378:metabolism*; D018918:Phacoemulsification; D012212:Rheology; D012965:Sodium Chloride / Q000378:metabolism*; D034421:Sus scrofa; D007507:Therapeutic Irrigation
chemical_list: D000085:Acetates; C030660:BSS solution; D004338:Drug Combinations; D005456:Fluorescent Dyes; D008081:Liposomes; D008903:Minerals; D009883:Ophthalmic Solutions; D012965:Sodium Chloride