title: Computer simulation of visual outcomes of wavefront-only corneal ablation.
abstract: OBJECTIVE
  To evaluate the effectiveness, predicted visual outcome, and limitations of a corneal ablation algorithm that uses wavefront aberration measurement alone without the need for corneal shape information.
  
  
  METHODS
  Contact Lens and Visual Optical Laboratory, School of Optometry, Queensland University of Technology, Brisbane, Australia.
  
  
  METHODS
  Corneal topography and wavefront error data from 22 eyes of 11 potential refractive surgery candidates were used. A computer simulation of the corneal ablation was performed, and the predicted postoperative visual outcome was assessed by calculating the resulting wavefront root-mean-square (RMS) values and visual Strehl ratios. Additionally, the effect of ablation alignment error was examined. Finally, the visual outcomes of the wavefront-only corneal ablations were compared to those in an age-matched group of 20 emmetropic patients.
  
  
  RESULTS
  Significant improvement in total and higher-order wavefront RMS was achieved postoperatively in both an ideal setting and in the case of ablation alignment errors. The predicted improvement in visual Strehl ratio in the potential refractive surgery candidates was significantly better than that in the untreated emmetropes. After additional simulated decentration of the pupil center by 150 microm, the result was slightly worse, but the change was found to not be significant when compared to the retinal image quality of emmetropes.
  
  
  CONCLUSIONS
  Wavefront-only corneal ablation algorithms could potentially lead to significantly better visual outcomes than those normally encountered in untreated emmetropes, provided that the alignment error is not large. The presented methodology may be used as a screening tool to predict patients' visual outcomes before the surgery.
authors.affiliation: School of Engineering, Griffith University, Gold Coast, Australia.
authors.forename: Fan
authors.initials: F
authors.lastname: Yi
authors.forename: D Robert
authors.initials: DR
authors.lastname: Iskander
authors.forename: Ross
authors.initials: R
authors.lastname: Franklin
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Collins
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001251:Astigmatism / Q000601:surgery; D003198:Computer Simulation; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D008954:Models, Biological; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*