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Impact of micropulsed ultrasound power settings on the efficiency and chatter associated with lens-fragment removal
Ist Teil von
Journal of cataract and refractive surgery, 2015-06, Vol.41 (6), p.1264-1267
Ort / Verlag
United States: Elsevier Inc
Erscheinungsjahr
2015
Quelle
MEDLINE
Beschreibungen/Notizen
Purpose To determine the optimum power settings in micropulsed ultrasound (US). Setting John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA. Design Experimental study. Methods Pig lenses hardened to be comparable to dense human cataracts were cut into 2.0 mm cubes and removed using micropulsed longitudinal US with previously optimized settings (6 milliseconds on and 6 milliseconds off and using a 0.9 mm 30-degree beveled bent phaco tip). The aspiration was set at 40 mL/min and the vacuum level at 550 mm Hg. Twenty lens cubes were tested with the power set from 10% to 100% in increments of 10%. Primary outcome measures were efficiency time (time to lens removal) and chatter (number of times the lens fragment visibly bounced off the tip). Results Efficiency time decreased with increasing power. There was a correlation between power and efficiency time ( R2 = 0.41, P = .046), which was more substantial between 30% and 100% power ( R2 = 0.71, P = .004). The mean number of chatter events did not differ significantly between power settings ( R2 = 0.012, P = .1195). Conclusions There was a 5-fold increase in efficiency between 10% power and 20% power, which likely indicates that there is a minimum power threshold for efficient breakup of the lens. Between 20% and 100% power, there was a linear, strong, and statistically significant improvement in efficiency in these lens fragments. In addition, with micropulsed US there was little chatter or microchatter throughout the power range. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.