title: Cumulative tip travel and implied followability of longitudinal and torsional phacoemulsification.
abstract: OBJECTIVE
  To compare surgeon-generated tip travel and surgical time of longitudinal and torsional phacoemulsification with straight and angled tips.
  
  
  METHODS
  Private practice, Marshalltown, Iowa, USA.
  
  
  METHODS
  The study analyzed surgical videos of 46 phacoemulsification cases performed by 1 surgeon. Based on the tip and type of ultrasound (US) used, the cases were prospectively assigned to 1 of 4 groups and operated on consecutively: straight tip/longitudinal US, straight tip/torsional US, angled tip/longitudinal US, and angled tip/torsional US. Digital Video Measurement System software (Caltex Scientific) was used to measure the phacoemulsification tip's travel during the removal of all 4 nuclear quadrants and the removal of quadrants 2 and 3 (2+3) and to determine surgical time. The cumulative travel distance and surgical time of the 4 groups were compared using analysis of variance.
  
  
  RESULTS
  The angled tip/torsional US combination reduced tip travel by more than 40% compared with the straight tip/longitudinal US when comparing travel to aspirate all 4 quadrants and quadrants 2+3. Surgical time in the removal of all 4 quadrants and quadrants 2+3 was significantly lower in the angled tip/torsional US group than in the other groups.
  
  
  CONCLUSIONS
  Torsional phacoemulsification using an angled tip required less surgeon-generated tip travel and less time, suggesting that nuclear material may be more efficiently approximated to and aspirated through the tip aperture throughout the phacoemulsification process. Shorter cumulative tip travel and less procedure time imply increased nuclear followability, fewer reacquisition movements, and increased phacoemulsification efficiency and safety.
authors.affiliation: Department of Ophthalmology and Visual Science, University of Utah, Salt Lake City, Utah, USA. jdavison@wolfeclinic.com
authors.forename: James A
authors.initials: JA
authors.lastname: Davison
mesh_terms: D006801:Humans; D007907:Lens Nucleus, Crystalline / Q000601:surgery; D018918:Phacoemulsification / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D013396:Suction; D013997:Time Factors; D013996:Time and Motion Studies; D014741:Video Recording