title: Threshold amplitude and frequency for ocular tissue release from a vibrating instrument: an experimental study.
abstract: OBJECTIVE
  During retinal pigment epithelium (RPE) and choroid graft translocation in the treatment of patients with exudative age-related macular degeneration, the adhesion of the graft to the translocation instrument complicated its submacular release. Vibration of the instrument improved the release of the graft. This study was conducted to validate the effectiveness of the principle of vibration and to determine the threshold amplitude and frequency required for development of an optimized instrument.
  
  
  METHODS
  An experimental in vitro model with fresh porcine RPE-choroid grafts was used. Release of the graft was studied by a masked observer for amplitudes in the range of 0.05 to 1.2 mm and frequencies in the range of 25 to 200 Hz in the horizontal plane.
  
  
  RESULTS
  The minimum threshold amplitude required to release the graft was approximately 0.15 mm from a frequency of 100 Hz and higher.
  
  
  CONCLUSIONS
  This study confirmed the clinical experience that vibration of an instrument induces the release of the RPE-choroid graft. The minimum threshold amplitude and frequency needed for optimum tissue release were estimated.
authors.affiliation: Department of Vitreoretinal Surgery, the Rotterdam Eye Hospital, Rotterdam, The Netherlands. kmaaijwee@hotmail.com
authors.forename: Kristel
authors.initials: K
authors.lastname: Maaijwee
authors.forename: Twan
authors.initials: T
authors.lastname: Koolen
authors.forename: Dagmar
authors.initials: D
authors.lastname: Rosenbrand
authors.forename: Elmer
authors.initials: E
authors.lastname: Jacobs
authors.forename: Sander
authors.initials: S
authors.lastname: Kleinheerenbrink
authors.forename: Arjan
authors.initials: A
authors.lastname: Knulst
authors.forename: Joop
authors.initials: J
authors.lastname: Bos
authors.forename: Wim P
authors.initials: WP
authors.lastname: Holland
authors.forename: Alex
authors.initials: A
authors.lastname: Brouwer
authors.forename: Jan C
authors.initials: JC
authors.lastname: van Meurs
authors.forename: Sander
authors.initials: S
authors.lastname: Schutte
mesh_terms: D000818:Animals; D002829:Choroid / Q000637:transplantation*; D008962:Models, Theoretical; D013508:Ophthalmologic Surgical Procedures / Q000295:instrumentation*; D010857:Pigment Epithelium of Eye / Q000637:transplantation*; D012684:Sensory Thresholds; D013552:Swine; D014732:Vibration