title: Outcomes of wavefront-guided laser in situ keratomileusis for hyperopia.
abstract: OBJECTIVE
  To determine the impact of wavefront-guided laser in situ keratomileusis (LASIK) for hyperopia on corrected distance visual acuity (CDVA), contrast sensitivity, and higher-order aberrations (HOAs).
  
  
  METHODS
  Centre for Contact Lens Research, University of Waterloo, Waterloo, Ontario, Canada.
  
  
  METHODS
  Case series.
  
  
  METHODS
  This study comprised patients who had LASIK for hyperopia. The HOAs up to the 4th order (5.0 mm pupil) in right eyes were analyzed.
  
  
  RESULTS
  The study enrolled 31 patients. The preoperative mean values were sphere, +2.60 diopters (D) ± 1.15 (SD) (range +1.00 to +5.00 D); astigmatism, -0.87 ± 0.74 D (range 0.00 to -3.75 D); and spherical equivalent (SE), +2.16 ± 1.00 D (range +0.63 to +4.50 D). The postoperative refractive SE was within ±0.50 D in 71.0% of eyes. The uncorrected distance visual acuity was 20/20 or better in 87.2% of eyes. There was no significant change in CDVA or contrast sensitivity (all P>.05). There was a significant change in Zernike coefficients Z(0,4), Z(-1,3), Z(-3,3), and Z(3,3) (range of mean absolute change ± SEM: 0.092 ± 0.013 μm to 0.208 ± 0.018 μm; all P<.001). Coefficients Z(-1,3) and Z(3,3) increased and Z(0,4) and Z(-3,3) decreased in magnitude; each had a reversal of sign. The only significant postoperative association was between low-contrast CDVA and Z(0,4) (r=0.617, P<.001).
  
  
  CONCLUSIONS
  Low-contrast CDVA after LASIK surgery for hyperopia was correlated with Z(0,4). There were no significant changes in CDVA or contrast sensitivity. The relative risk for losing low-contrast CDVA increased if more than 1 Zernike term had a sign change.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. njkeir@uwaterloo.ca
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Keir
authors.forename: Trefford
authors.initials: T
authors.lastname: Simpson
authors.forename: Natalie
authors.initials: N
authors.lastname: Hutchings
authors.forename: Lyndon
authors.initials: L
authors.lastname: Jones
authors.forename: Desmond
authors.initials: D
authors.lastname: Fonn
mesh_terms: D000328:Adult; D000368:Aged; D015350:Contrast Sensitivity / Q000502:physiology; D057108:Corneal Wavefront Aberration / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult