title: Wavefront aberrations in eyes with decentered ablations.
abstract: OBJECTIVE
  To compare the refractive and functional outcomes and wavefront profiles in eyes with decentered ablations and eyes with well-centered ablations.
  
  
  METHODS
  Medical Research Foundation, Chennai, Tamil Nadu, India.
  
  
  METHODS
  This retrospective analysis comprised eyes with topographically diagnosed decentered ablations after laser in situ keratomileusis (LASIK). Refraction, contrast sensitivity, and ocular wavefront aberrations were measured preoperatively and 1 month postoperatively. The induced aberrations in these eyes were compared with those in eyes with well-centered ablations.
  
  
  RESULTS
  Forty-six eyes (38 patients) had decentered ablations and 60 eyes (32 patients), well-centered ablations. The mean decentration in the study group was 0.86 mm +/- 0.29 (SD) (range 0.35 to 1.61 mm). There was no significant correlation between decentration and attempted refractive correction. There was, however, a statistically significant (P<.05) linear correlation between the distance of decentration and the magnitude of induced tilt (r = -0.31), coma (r = -0.41), and secondary astigmatism (r = 0.36). The induced changes in tilt, oblique astigmatism, vertical coma, and spherical aberration were statistically significantly higher in eyes with decentered ablations than in eyes with well-centered ablations. A statistically significantly higher percentage of eyes (87%) with well-centered ablations than eyes with decentered ablations (70%) had a postoperative uncorrected visual acuity (UCVA) of 20/20 or better. There was no significant difference in contrast sensitivity between groups.
  
  
  CONCLUSIONS
  Eyes with decentered ablations had a significantly higher magnitude of induced aberrations and lower UCVA than eyes with well-centered ablations.
authors.affiliation: Medical & Vision Research Foundation, Tamil Nadu, India. drpp@snmail.org
authors.forename: Prema
authors.initials: P
authors.lastname: Padmanabhan
authors.forename: Michael
authors.initials: M
authors.lastname: Mrochen
authors.forename: Deepa
authors.initials: D
authors.lastname: Viswanathan
authors.forename: Subam
authors.initials: S
authors.lastname: Basuthkar
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000503:physiopathology; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014786:Vision Disorders / Q000209:etiology* / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult