title: Radial keratotomy does not affect intraocular pressure.
abstract: BACKGROUND
  Recent reports have suggested that a secondary effect of radial keratotomy may be a reduction in intraocular pressure (IOP) levels.
  
  
  METHODS
  In an effort to study the relationship of radial keratotomy to IOP, we compared the mean IOP from the baseline and follow-up visits during 1 year after surgery of operated versus nonoperated eyes of patients enrolled in the Prospective Evaluation of Radial Keratotomy (PERK) study. To investigate if radial keratotomy had more of an effect on eyes with higher baseline IOPs, the same analysis was performed on a subset (134 patients) who had a baseline IOP of 15 mm Hg or greater.
  
  
  RESULTS
  The average baseline IOP for both operated eyes and nonoperated eyes was 14.6 mm Hg. There was no significant difference in mean IOP between operated and nonoperated eyes across all time points (p = .18). Although mean IOP changed over time, it did not clinically differ in operated versus nonoperated eyes at any time point. These findings were similar in the analysis of eyes with higher baseline IOP (15 mm Hg or greater).
  
  
  CONCLUSIONS
  We conclude that the radial keratotomy performed in the PERK study had no effect on IOP within 1 year after surgery.
authors.affiliation: National Eye Institute, Biometry and Epidemiology Program, National Institutes of Health, Bethesda, MD 20892.
authors.forename: S M
authors.initials: SM
authors.lastname: Sastry
authors.forename: R D
authors.initials: RD
authors.lastname: Sperduto
authors.forename: G O
authors.initials: GO
authors.lastname: Waring
authors.forename: N A
authors.initials: NA
authors.lastname: Remaley
authors.forename: M J
authors.initials: MJ
authors.lastname: Lynn
authors.forename: E
authors.initials: E
authors.lastname: Blanco
authors.forename: D N
authors.initials: DN
authors.lastname: Miller
mesh_terms: D000328:Adult; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D007646:Keratotomy, Radial; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D015814:Ocular Hypotension / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies