title: Visual outcome and contrast sensitivity after photorefractive keratectomy in low to moderate myopia: wavefront-optimized versus conventional methods.
abstract: OBJECTIVE
  To compare visual outcomes and contrast sensitivity after wavefront-optimized or conventional photorefractive keratectomy (PRK) in myopic patients with or without astigmatism.
  
  
  METHODS
  Vanak Eye Surgery Center, Tehran, Iran.
  
  
  METHODS
  Comparative case series.
  
  
  METHODS
  Patients with low to moderate myopia with or without astigmatism were allocated into 2 groups. The study group was treated with wavefront-optimized PRK (Allegretto Wave Eye-Q software version 2.020 default treatment) and the control group, with conventional PRK (Technolas 217z). In all cases, treatments were bilateral and performed with the same device. Baseline and 3-month postoperative measures were uncorrected and corrected distance visual acuities, manifest refraction, and contrast sensitivity.
  
  
  RESULTS
  Each group comprised 66 eyes. The mean preoperative spherical equivalent refraction improved from -2.99 diopters (D) ± 1.02 (SD) preoperatively to -0.08 ± 0.26 D 3 months postoperatively in the study group and from -2.66 ± 0.95 D to 0.01 ± 0.30 D, respectively, in the control group. In both groups, the postoperative mesopic and photopic contrast sensitivity decreased significantly at most spatial frequencies. The postoperative decrease in contrast sensitivity in both groups was comparable except at spatial frequencies of 3 cycles per degree (cpd) under mesopic conditions and 12 cpd under photopic conditions, frequencies at which the control group had a greater reduction.
  
  
  CONCLUSIONS
  Visual acuity and refractive error outcomes were similar in both treatment groups. After 3 months, mesopic and photopic contrast sensitivity were significantly decreased in both groups; the reduction in the 2 groups was almost comparable.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: Department of Ophthalmology, Shaheed Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Nader
authors.initials: N
authors.lastname: Nassiri
authors.forename: Sare
authors.initials: S
authors.lastname: Safi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Aghazade Amiri
authors.forename: Kourosh
authors.initials: K
authors.lastname: Sheibani
authors.forename: Hamid
authors.initials: H
authors.lastname: Safi
authors.forename: Nekoo
authors.initials: N
authors.lastname: Panahi
authors.forename: Nariman
authors.initials: N
authors.lastname: Nassiri
mesh_terms: D057128:Aberrometry; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D015350:Contrast Sensitivity / Q000502:physiology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000379:methods*; D011446:Prospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult