title: Comparative clinical trial of ultrasound phacoemulsification with and without the WhiteStar system.
abstract: OBJECTIVE
  To compare the postoperative outcomes of cataract surgery performed with the Sovereign 4.0 system or the Sovereign system with WhiteStar power modulation.
  
  
  METHODS
  Ambulatory surgery centers at 4 sites in the United States.
  
  
  METHODS
  This was a 3-month, open-label, randomized, parallel-group comparative clinical trial in patients with visually interfering cataract. Surgeons used the divide-and-conquer phacoemulsification technique for nuclear removal. An intraocular lens was implanted using the recommended insertion system. Primary operative outcome measures were equivalent phaco time (EPT), percentage of phaco power, amount of balanced salt solution used, and surgical complications. Patients were seen 1 day and 3 months after surgery. Postoperative outcome measures were the change in endothelial cell count from the preoperative visit to 3 months, corneal clarity, inflammation, and corneal thickness.
  
  
  RESULTS
  The Sovereign with WhiteStar group had 48 patients and the Sovereign 4.0 group, 49 patients. Mean EPT and mean percentage of power were significantly lower in the Sovereign with WhiteStar group. Mean EPT was 6.67 seconds +/- 8.2 (SD) in the Sovereign with WhiteStar group and 8.59 +/- 9.3 seconds (P = .01) in the Sovereign 4.0 group. Mean percentage of phaco power was 6.41% +/- 3.3% in the Sovereign with WhiteStar group and 8.51% +/- 4.9% in the Sovereign 4.0 group (P = .01). The Sovereign with WhiteStar group lost significantly fewer endothelial cells (-319.6 +/- 634.2 cells/mm(2)) than the Sovereign 4.0 group (-430.3 +/- 594.6 cells/mm(2)) (P = .01). Corneal clarity, cells and flare, and pachymetry were comparable with the exception of the 3-month visit. The mean change in baseline central pachymetry showed significantly less corneal thickening in the Sovereign with WhiteStar group.
  
  
  CONCLUSIONS
  The Sovereign with WhiteStar power modulation system provides effective lens removal at lower levels of phaco power and ultrasound energy than the Sovereign 4.0 system. Lower ultrasound levels may reduce the risk for endothelial cell loss during phacoemulsification.
authors.affiliation: Fishkind and Bakewell Eye Care and Surgery Center, Tucson, Arizona 85704, USA. wfishkind@earthlink.net
authors.forename: William
authors.initials: W
authors.lastname: Fishkind
authors.forename: Brock
authors.initials: B
authors.lastname: Bakewell
authors.forename: Eric D
authors.initials: ED
authors.lastname: Donnenfeld
authors.forename: Aron D
authors.initials: AD
authors.lastname: Rose
authors.forename: L Andrew
authors.initials: LA
authors.lastname: Watkins
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Olson
mesh_terms: D002452:Cell Count; D004728:Endothelium, Corneal / Q000473:pathology; D006801:Humans; D007431:Intraoperative Complications; D019654:Lens Implantation, Intraocular; D018918:Phacoemulsification / Q000295:instrumentation / Q000379:methods*; D011183:Postoperative Complications; D016896:Treatment Outcome