Threshold amplitude and frequency for ocular tissue release from a vibrating instrument: an experimental study.
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.
Maaijwee
Kristel
K
Department of Vitreoretinal Surgery, the Rotterdam Eye Hospital, Rotterdam, The Netherlands. kmaaijwee@hotmail.com
Koolen
Twan
T
Rosenbrand
Dagmar
D
Jacobs
Elmer
E
Kleinheerenbrink
Sander
S
Knulst
Arjan
A
Bos
Joop
J
Holland
Wim P
WP
Brouwer
Alex
A
van Meurs
Jan C
JC
Schutte
Sander
S
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