title: Ultrasonic transmission in viscoelastic substances.
abstract: OBJECTIVE
  To study the propagation of ultrasonic shock waves in viscoelastic agents and the resulting corneal load.
  
  
  METHODS
  University Siegen, Institute for Mechanics and Control Engineering, Siegen, Germany.
  
  
  METHODS
  The anterior chamber of a manufactured artificial eye was constructed according to anatomic dimensions. Three openings were drilled--for the phaco tip, for the exchange of a viscoelastic agent or water, and for the shock-wave sensor. The sensor was fixed to the area corresponding to the corneal apex. The sensor signal was analyzed using a direct oscilloscope that measured the amplitude reaching the corneal apex. Shock-wave propagation in several viscoelastic agents was compared with that in balanced salt solution.
  
  
  RESULTS
  In hydroxypropyl methylcellulose, the shock wave was amplified or influenced slightly. In hyaluronic-acid preparations, acoustic dampening occurred.
  
  
  CONCLUSIONS
  Removal of hyaluronic-acid derivatives prior to phacoemulsification is not necessary.
authors.affiliation: University Eye Hospital Tübingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Frohn
authors.forename: H B
authors.initials: HB
authors.lastname: Dick
authors.forename: C P
authors.initials: CP
authors.lastname: Fritzen
authors.forename: M
authors.initials: M
authors.lastname: Breitenbach
authors.forename: H J
authors.initials: HJ
authors.lastname: Thiel
mesh_terms: D000867:Anterior Chamber / Q000000981:diagnostic imaging*; D001831:Body Temperature; D002809:Chondroitin Sulfates / Q000737:chemistry*; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry*; D065347:Hypromellose Derivatives; D007267:Injections; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D008953:Models, Anatomic; D018918:Phacoemulsification; D014465:Ultrasonics; D014463:Ultrasonography
chemical_list: D065347:Hypromellose Derivatives; D006820:Hyaluronic Acid; D008747:Methylcellulose; D002809:Chondroitin Sulfates