title: A prospective randomized clinical trial of laser in situ keratomileusis with two different lasers.
abstract: OBJECTIVE
  To compare optical quality, visual function, corneal shape, ocular wavefront aberrations, and patient-reported symptoms and satisfaction after laser in situ keratomileusis (LASIK) with two different excimer lasers.
  
  
  METHODS
  Prospective randomized clinical trial.
  
  
  METHODS
  In an institutional practice setting, 60 eyes of 30 patients with low to moderate myopia were randomized to receive LASIK in one eye with the Technolas 217A; the other eye was treated with the VISX S3. Patients were followed for 6 months after surgery. The primary outcome measure was best spectacle-corrected visual acuity.
  
  
  RESULTS
  At 6 months, the mean best-spectacle corrected high contrast visual acuity was similar between the two treatment groups: mean difference (95% confidence interval) was -0.01 logarithm of minimal angle of resolution (logMAR) (-0.03 to +0.01 logMAR). Uncorrected visual acuity differences were also not significant. The difference in residual spherical equivalent subjective refractive error between treatment groups was -0.15 diopter (-0.34 to +0.05 diopter). Spherical aberration increased in both groups after treatment, and the change in root mean square (RMS) ocular wavefront error was greater in the VISX group by +0.07 microm (+0.03 to +0.11 microm). After LASIK, corneal curvature was steeper in the midperipheral region among VISX-treated eyes by +1.39 diopters (+2.06 to +0.72 diopters). There were no patient-reported differences in satisfaction between eyes.
  
  
  CONCLUSIONS
  There were no significant differences in visual acuity or refractive outcomes attributed to either laser under any of the conditions measured. There was also no significant difference in patient-reported symptoms, satisfaction with treatment, or eye preference associated with either laser. Additional study is needed to establish the importance of differences in higher-order optical aberrations and corneal shape that we observed in these two treatment groups.
authors: College of Optometry, The Ohio State University, Columbus 43210, USA.
authors: Michael D
authors: MD
authors: Twa
authors: Richard G
authors: RG
authors: Lembach
authors: Mark A
authors: MA
authors: Bullimore
authors: Cynthia
authors: C
authors: Roberts
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D003315:Cornea / Q000033:anatomy & histology / Q000502:physiology*; D003319:Corneal Stroma / Q000601:surgery; D019781:Corneal Topography; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D017060:Patient Satisfaction; D011183:Postoperative Complications; D011446:Prospective Studies; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*