Ultrasonic-generated fluid velocity with Sovereign WhiteStar micropulse and continuous phacoemulsification.
OBJECTIVE
To evaluate and compare ultrasonic turbulence created by conventional and micropulse ultrasound technology.


METHODS
Sonora Medical Systems, Longmont, Colorado, USA.


METHODS
A high-resolution digital ultrasound probe imaged the zone around a phacoemulsification tip. Doppler analysis allowed determination of flow. The fluid velocity was measured at 4 levels of ultrasound power at a constant flow, comparing the ultrasonic conditions of continuous energy to WhiteStar micropulses.


RESULTS
In addition to the normal baseline irrigation and aspiration, fluid movement was detected directly below the phaco tip, produced by a nonlinear effect known as acoustic streaming. Acoustic streaming increased with increased phacoemulsification power for both conditions. At each of the 4 levels of power, fluid velocity away from the tip was less with micropulse technology than with continuous phacoemulsification.


CONCLUSIONS
The demonstrated decrease in acoustic streaming flow away from the phaco tip with Sovereign WhiteStar micropulse technology compared to conventional ultrasound provides an objective explanation for clinical observations of increased stability of nuclear fragments at the tip and less turbulence in the anterior chamber during phacoemulsification. This methodology can be used to examine and compare fluid flow and turbulence under a variety of clinically relevant conditions.
Steinert
Roger F
RF
Department of Ophthalmology, University of California, Irvine, Irvine, California 92651-4375, USA.
Schafer
Mark E
ME
D000085:Acetates / Q000378:metabolism*; D004338:Drug Combinations; D008903:Minerals / Q000378:metabolism*; D018918:Phacoemulsification / Q000295:instrumentation*; D012965:Sodium Chloride / Q000378:metabolism*; D007507:Therapeutic Irrigation; D014465:Ultrasonics; D018615:Ultrasonography, Doppler, Color; D014732:Vibration; D014741:Video Recording
D000085:Acetates; C030660:BSS solution; D004338:Drug Combinations; D008903:Minerals; D012965:Sodium Chloride