title: The effect of laser refractive surgery on the on-field performance of professional baseball players.
abstract: BACKGROUND
  The aim of this study was to determine the effect of laser refractive surgery on the offensive performance of professional baseball players.
  
  
  METHODS
  Extensive search of the public media was conducted to determine which major league baseball players had undergone laser refractive surgery and when the procedure was performed. Baseball performance data were then used to determine presurgery and postsurgery baseball performance averages. A total of 17 position players were identified; however, 5 of these players were not considered in the analysis owing to insufficient playing experience either before or after the laser procedure.
  
  
  RESULTS
  No statistically significant or practically significant difference was found between the presurgery and postsurgery means on either on-base percentage (P = 0.31), batting average (P = 0.39), slugging percentage (P = 0.66) or on-base plus slugging (OPS; P = 0.997) of major league baseball players.
  
  
  CONCLUSIONS
  These preliminary findings suggest that professional baseball players should not expect a laser refractive surgical procedure to significantly improve their offensive baseball performance, despite the elimination of glasses or contact lens wear.
authors.affiliation: Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA. drlaby@drlaby.com
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Laby
authors.forename: David G
authors.initials: DG
authors.lastname: Kirschen
authors.forename: Paul
authors.initials: P
authors.lastname: De Land
mesh_terms: D001484:Baseball; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009216:Myopia / Q000601:surgery*; D011930:Reaction Time / Q000502:physiology*; D012189:Retrospective Studies; D014785:Vision, Ocular / Q000502:physiology*