title: Aspheric wavefront-guided versus wavefront-guided LASIK for myopic astigmatism with the Technolas 217z100 excimer laser.
abstract: OBJECTIVE
  To compare clinical outcomes of wavefront-guided LASIK with and without aspheric compensation in myopic eyes.
  
  
  METHODS
  In this observational, single-center study, 134 eyes were treated using an aspheric module in combination with wavefront-guided profiles (PTA-algorithm) and compared to 146 eyes treated with the predecessor wavefront-guided software (APT) that has no aspheric compensation. All treatment plans included the Rochester nomogram that accounts for the preoperative manifest refraction and interaction of higher order aberrations. Active eye-tracking (including cyclorotational movements) was utilized during photoablation.
  
  
  RESULTS
  Results at the 3-month follow-up: 67 % of PTA-treated eyes and 39 % of APT-treated eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 or better. Change in mean higher order aberration root-mean-square (HOA RMS) after PTA treatments was not statistically significant (p = 0.18). The increase in HOA RMS after APT treatments was statistically significant (p = 0.003). Change in mean postop spherical aberration (SA) after PTA treatments was not statistically significant (p = 0.27). The change in SA after APT treatments was statistically significant (p = 0.001). In both cohorts, mean uncorrected low-contrast visual acuity was statistically not different to preoperative corrected values.
  
  
  CONCLUSIONS
  Adding an aspheric compensation to wavefront-guided myopic LASIK statistically improved clinical results in terms of visual acuity and refractive outcomes. Low-contrast visual acuity was not negatively affected in either group. While in APT-treated eyes mean HOA RMS and mean SA were significantly increased postoperatively, PTA-treated eyes showed neither induced HOA RMS nor induced SA.
authors.affiliation: Eye Department St Francis Hospital, Center for Refractive Surgery, Muenster, Germany. taneri@refraktives-zentrum.de
authors.forename: Suphi
authors.initials: S
authors.lastname: Taneri
authors.forename: Saskia
authors.initials: S
authors.lastname: Oehler
authors.forename: Scott M
authors.initials: SM
authors.lastname: MacRae
mesh_terms: D057128:Aberrometry; D000328:Adult; D000368:Aged; D000465:Algorithms; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D057108:Corneal Wavefront Aberration / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D049451:Nomograms; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult