The Sovereign WhiteStar ICE (Increased Control and Efficiency) system (Advanced Medical Optics [AMO]), with its ultrasound pulse-shaping technology, is proving to be more efficient in recent clinical studies. The results of two studies reported at the American Society of Cataract and Refractive Surgery annual meeting added to that body of information.
In the first study, William J. Fishkind, MD, described the increased control and efficiency during preocclusion phacoemulsification. "Preocclusion phaco is the time when the phaco tip is not occluded by nuclear fragments. During occlusion, vacuum increases and flow stops," he said.
Occlusion, he further explained, is inevitably followed by a surge. "If we can move the phaco procedure to the preocclusive mode, we can avoid surge," he emphasized. Dr. Fishkind is clinical professor of ophthalmology, University of Utah, Salt Lake City, clinical instructor of ophthalmology, University of Arizona, Tucson, and co-director, Fishkind & Bakewell Eye Care and Surgery Center, Tucson.
"In preocclusive phaco, the material is near the tip, there is flow, there is vacuum, and there is no occlusion. Hyperpulse causes preocclusion because the pulses are very short and they move the material away micrometers from the phaco tip, which is sufficient to create the preocclusive environment," Dr. Fishkind explained.
The millisecond 'kicker'
The kicker can be adjusted to the same height, he pointed out, that is, 7% of the total set phaco power, or it can be set higher or lower based on the desires of the surgeon. The duration of the kicker also can be adjusted. Dr. Fishkind reported that he likes it f to set the same time all the way up and for the same duration during the procedure.
Dr. Fishkind demonstrated phaco performed without ICE and showed that spindling occurs, which is the term that refers to a nuclear fragment sticking to the phaco tip and requiring a second instrument to push it off the tip.
"If spindling occurs nothing is moving that material off the phaco tip. When the kicker is added, the ICE, the fragment is emulsified very efficiently and no spindling occurs. The change in efficiency moves the procedure along substantially," he noted.
In addition to AMO, Bausch & Lomb has created a molded pulse wave that brings the nuclear material to the phaco tip without occluding the tip and allows the material to be emulsified, according to Dr. Fishkind.