title: The effect of laser in situ keratomileusis on low contrast vision.
abstract: OBJECTIVE
  To determine the effects of laser in situ keratomileusis (LASIK) on low contrast visual acuity.
  
  
  METHODS
  Thirty eyes of 15 LASIK patients with myopia and astigmatism were evaluated preoperatively, and 1 and 3 months postoperatively. High contrast visual acuity (HCVA), low contrast visual acuity (LCVA), and contrast threshold were determined.
  
  
  RESULTS
  Mean spherical correction (SE) was -3.24 +/- 1.90 D; 16 eyes had a mean SE between -1.00 and -3.00 D, and 14 eyes were between -3.25 and -6.50 D. There was no significant change in HCVA observed at 1 and 3 months in any eye. There was a decrease in LCVA in eyes with a correction >3 D SE at 1 month (P=.04), which returned to normal at 3 months (P=.13). There was an increase in the contrast threshold at 1 month (P=.016). When eyes were divided into groups, those with >3D SE correction had an increase in contrast threshold at 1 month (P=.002); no change was seen in eyes with <3D SE correction (P=.15). At 3 months, contrast threshold was similar to baseline values in all eyes (P=.226).
  
  
  CONCLUSIONS
  LASIK transiently decreased low contrast visual function in patients with greater than 3.00 D of myopic correction.
authors.affiliation: Department of Ophthalmology, University of Toronto-Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Joseph Anthony J
authors.initials: JA
authors.lastname: Tumbocon
authors.forename: Palanisamy
authors.initials: P
authors.lastname: Suresh
authors.forename: Allan
authors.initials: A
authors.lastname: Slomovic
authors.forename: David S
authors.initials: DS
authors.lastname: Rootman
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular; D015354:Vision, Low / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology