title: Case report: the correction of a high magnitude of astigmatism with laser-assisted in situ keratomileusis.
abstract: BACKGROUND
  Laser-assisted in situ keratomileusis (LASIK) has undergone several evolutions since it was first approved by the U.S. Food and Drug Administration. Currently, excimer lasers are approved by the U.S. Food and Drug Administration to treat refractive errors with a standard ablation profile, a wavefront-optimized ablation profile, or a wavefront-guided ablation profile. Wavefront-optimized ablation profiles provide a simple method to precompensate for the expected fourth-order spherical aberration and higher-order astigmatism in the average eye.
  
  
  METHODS
  We report a case of a 39-year-old white man, with a high magnitude of mixed astigmatism in the right and left eyes, who was seeking refractive surgical options because he was unable to tolerate contact lenses. The patient underwent bilateral wavefront-optimized LASIK to correct his high degree of astigmatism. Wavefront-guided ablation, as in this patient, can not always be performed because the parameters are not within the allowable treatment profile. Four months after the primary LASIK treatment, the patient underwent a bilateral wavefront-optimized LASIK enhancement for residual astigmatism.
  
  
  CONCLUSIONS
  This case focuses on the utilization of a wavefront-optimized LASIK treatment profile to eliminate a high magnitude of astigmatic refractive error without inducing higher-order aberrations. Wavefront-guided treatments are not required in most cases but should be considered if the magnitude of preoperative root-mean-square higher-order aberrations is greater than 0.35 μm. Wavefront-optimized aspheric corneal ablations attempt to avoid reducing the prolate eccentricity of the average cornea, and optimized treatments have shown improved visual outcomes compared with conventional LASIK treatments. A thorough knowledge of refractive surgery is important for any treating eye care practitioner to provide patients with the full range of options to correct all types of refractive errors.
authors.affiliation: Mann Eye Institute and Laser Centers, Houston, Texas 77002, USA. pbrunson@manneye.com
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Brunson
authors.forename: Paul M
authors.initials: PM
authors.lastname: Mann
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000473:pathology / Q000601:surgery*; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D012029:Refraction, Ocular; D012720:Severity of Illness Index; D014792:Visual Acuity