Ultrasonic transmission in viscoelastic substances.
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.
Frohn
A
A
University Eye Hospital Tübingen, Germany.
Dick
H B
HB
Fritzen
C P
CP
Breitenbach
M
M
Thiel
H J
HJ
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
D065347:Hypromellose Derivatives; D006820:Hyaluronic Acid; D008747:Methylcellulose; D002809:Chondroitin Sulfates