title: Comparison of corneal endothelial changes following phacoemulsification with transversal and torsional phacoemulsification machines.
abstract: OBJECTIVE
  To compare and evaluate the phacoemulsification parameters and postoperative endothelial cell changes of two different phacoemulsification machines, each with different modes, but also to assess the relationship between postoperative endothelial cell loss and the phacoemulsification parameters, as well as the other factors in both groups.
  
  
  METHODS
  This prospective observational study was comprised of consecutive eligible cataract patients operated with phacoemulsification technique performed by the same surgeon using either a WHITESTAR Signature Ellips FX (transversal, group 1) or Infiniti OZil IP (torsional, group 2) machine.
  
  
  RESULTS
  The study included 86 patients. Baseline characteristics in the groups were similar. The median nuclear sclerosis grade was 3 (2-4) in the first group and 2 (2-4) in the second group (P=0.265). Both groups had similar phacoemulsification needle times (group 1: 60.63±36 s; group 2: 55.98±30 s; P=0.789). The percentage of endothelial cell loss 30d after surgery ranged from 3% to 15% with a median of 7% in group 1, and from 2% to 13% with a median of 6% in group 2; however, there was no statistically significant difference between the groups (P=0.407). Hexagonality (P=0.794) and the coefficient of variation (CV; P=0.142) did not differ significantly between the groups before and 30d after surgery. A significant positive correlation was found between the endothelial cell loss and nuclear sclerosis grade (group 1: P<0.001; group 2: P<0.001) and between the endothelial cell loss and average phacoemulsification power (group 1: P=0.007; group 2: P=0.008).
  
  
  CONCLUSIONS
  Both of these machines were efficient, with similar endothelial cell loss. This endothelial cell loss was related to the increased nuclear sclerosis grade and increased phacoemulsification power.
authors.affiliation: Department of Ophthalmology and Vision Sciences, Kayseri Traning and Research Hospital, Kocasinan-Kayseri 38010, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ataş
authors.affiliation: Department of Ophthalmology and Vision Sciences, Kayseri Traning and Research Hospital, Kocasinan-Kayseri 38010, Turkey.
authors.forename: Süleyman
authors.initials: S
authors.lastname: Demircan
authors.affiliation: Department of Ophthalmology and Vision Sciences, Kayseri Traning and Research Hospital, Kocasinan-Kayseri 38010, Turkey.
authors.forename: Arzu Seyhan
authors.initials: AS
authors.lastname: Karatepe Haşhaş
authors.affiliation: Department of Ophthalmology and Vision Sciences, Kayseri Traning and Research Hospital, Kocasinan-Kayseri 38010, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Gülhan
authors.affiliation: Department of Biostatistics, Faculty of Medicine, Erciyes University, Kocasinan-Kayseri 38010, Turkey.
authors.forename: Gökmen
authors.initials: G
authors.lastname: Zararsız
keywords: endothelial cell changes; phacoemulsification; torsional; transversal