title: Corneal haze among blue eyes and brown eyes after photorefractive keratectomy.
abstract: BACKGROUND
  To compare the incidence and severity of corneal haze after photorefractive keratectomy (PRK) among white patients with blue eyes and Saudi patients with brown eyes.
  
  
  METHODS
  Retrospective, nonrandomized, comparative trial.
  
  
  METHODS
  A total of 150 patients (71 females and 79 males) were included in this study. Two hundred sixty-six eyes of 150 patients were subjected to PRK. One hundred blue eyes of 50 white patients and 166 brown eyes of 100 Saudi patients were included in this study.
  
  
  METHODS
  Two hundred sixty-six eyes of 150 patients were subjected to PRK with the Chiron Technolas Keracor 117C for the correction of myopia and astigmatism.
  
  
  METHODS
  All patients had complete ophthalmologic examinations, visual acuity testing, intraocular pressure, pachymetry, corneal haze assessment (0-4+), and computerized corneal topography.
  
  
  RESULTS
  There were 266 eyes of 150 patients with 100 blue irides and 166 brown irides. The spherical equivalent was -0.50 diopter (D) to -8.75 D. The mean postoperative spherical equivalent at 6 months was -0.063 D (standard deviation [SD], +/-0.595) in blue eyes compared to -0.28 D (SD, +/-0.683) in brown eyes (P = 0.006). Ninety-five (95%) of 100 of the blue eyes achieved +/- 1 D of attempted correction compared to 148 (89.2%) of the 166 brown eyes. All patients with blue eyes had a visual acuity of 20/30 or better compared to 153 (92.2%) of the 166 brown eyes (P = 0.009). Forty-eight (18.04%) eyes had minimal to mild haze, 3 (1.12%) eyes had moderate haze, and 2 (0.75%) eyes had severe haze. The incidence of corneal haze among brown eyes was 48 (28.9%) of 166 eyes compared to 5 (5%) of 100 in blue eyes (P < 0.001). The difference remained significant after adjustment for age and gender with a P value of 0.0283. The relative risk for developing haze in brown eyes was found to be 7.72.
  
  
  CONCLUSIONS
  The incidence of corneal haze after PRK was significantly higher among Saudi patients with brown irides than among white patients with blue irides. This suggests that racial factors may play a role in the development of corneal haze.
authors.affiliation: The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia.
authors.forename: K F
authors.initials: KF
authors.lastname: Tabbara
authors.forename: H F
authors.initials: HF
authors.lastname: El-Sheikh
authors.forename: N A
authors.initials: NA
authors.lastname: Sharara
authors.forename: B
authors.initials: B
authors.lastname: Aabed
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D003318:Corneal Opacity / Q000208:ethnology / Q000209:etiology*; D019781:Corneal Topography; D005060:Europe / Q000453:epidemiology; D005127:Eye Color; D005260:Female; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D009656:North America / Q000453:epidemiology; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D014792:Visual Acuity