title: Outcomes of myopic LASIK with and without NIDEK active torsion error correction.
abstract: OBJECTIVE
  To compare refractive outcomes and higher order aberrations of eyes that underwent LASIK for myopia with astigmatism with or without active cyclotorsion error correction.
  
  
  METHODS
  This was a contralateral eye study of 48 eyes of 24 patients who underwent LASIK using the NIDEK Advanced Vision Excimer laser platform (NAVEX), treating one eye with active cyclotorsion error correction (TEC eyes) and the fellow eye without active cyclotorsion error correction (without TEC eyes). Postoperatively, the refractive outcomes, including postoperative astigmatism and higher order aberrations were compared between groups using the t test. A P value <.05 was considered statistically significant. Three-month postoperative outcomes are presented.
  
  
  RESULTS
  Preoperative manifest refraction spherical equivalent was -3.59+/-1.60 diopters (D) (range: -1.25 to -6.75 D) for the TEC group and -3.82+/-1.89 D (range: -1.38 to -8.63 D) for the without TEC group. No statistically significant differences were noted in postoperative visual acuity between groups (P>.05). The TEC eyes had statistically significant lower postoperative cylinder (0.28+/-0.27 D [range: 0 to -0.75 D] for the TEC group vs 0.49+/-0.30 D [range: 0 to -1.00 D] for the without TEC group; P=.02). A mean decrease in root-mean-square (RMS) of higher order aberration was noted in the TEC eyes, and a mean increase was noted in RMS of higher order aberration for the without TEC eyes at both 5- and 6-mm pupil diameters. The TEC eyes had statistically significantly lower RMS of higher order aberration (P<.01).
  
  
  CONCLUSIONS
  Active torsion error correction with the NIDEK NAVEX platform statistically significantly increases the predictability of astigmatism correction and reduces the induction of higher order aberrations of eyes undergoing LASIK.
authors.affiliation: Optical Express, London, United Kingdom. drjanventer@gmail.com
authors.forename: Jan
authors.initials: J
authors.lastname: Venter
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D014102:Torsion Abnormality / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology