title: Contrast sensitivity evaluation after laser in situ keratomileusis.
abstract: OBJECTIVE
  To determine the effects of laser in situ keratomileusis (LASIK) on best-corrected visual acuity (BCVA) and contrast sensitivity.
  
  
  METHODS
  Prospective, observational case series.
  
  
  METHODS
  One hundred twelve eyes, in 65 patients with myopia and myopia with astigmatism, who underwent LASIK. TESTING AND MAIN OUTCOME MEASURES: Best-corrected visual acuity using the Snellen visual acuity chart and contrast sensitivity using the CSV 1000 (Vector Vision, Dayton OH) was tested before surgery and 1 week, 1 month, and 3 months after surgery in patients who underwent LASIK.
  
  
  RESULTS
  Contrast sensitivity was depressed for patient eyes with spherical equivalence (SE) between -1.25 diopters (D) and -13.75 D, at 12 cycles/degree for at least 3 months and at 18 cycles/degree for 1 week after LASIK. For patient eyes with SE between -1.25 D and -6.00 D, contrast sensitivity was depressed only at 12 cycles/degree for at least 3 months after LASIK. For patient eyes with SE between -6.00 D and -13.75 D, contrast sensitivity was depressed at 6, 12, and 18 cycles/degree 1 week after LASIK but returned toward preoperative levels by 1 month after surgery. Despite the slight decreases in contrast sensitivity, all scores were still within the range of normal values except for 12 cycles/degree for 3 months and 18 cycles/degree at 1 week after surgery in the high myopia group. Although highly myopic patients, compared with patients with low myopia, had slightly less BCVA before surgery, both groups maintained their preoperative BCVA at all postoperative visits.
  
  
  CONCLUSIONS
  Based on this study, we conclude that LASIK has little effect on BCVA and contrast sensitivity for up to 3 months after surgery.
authors.affiliation: Pannu Eye Institute, Fort Lauderdale, Florida, USA.
authors.forename: S
authors.initials: S
authors.lastname: Mutyala
authors.forename: M B
authors.initials: MB
authors.lastname: McDonald
authors.forename: K A
authors.initials: KA
authors.lastname: Scheinblum
authors.forename: M D
authors.initials: MD
authors.lastname: Ostrick
authors.forename: S F
authors.initials: SF
authors.lastname: Brint
authors.forename: H
authors.initials: H
authors.lastname: Thompson
mesh_terms: D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D015350:Contrast Sensitivity / Q000502:physiology*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery; D011446:Prospective Studies; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology