title: Preliminary results of photorefractive keratectomy in active-duty United States Navy personnel.
abstract: OBJECTIVE
  To evaluate the safety, efficacy, and quality of vision after photorefractive keratectomy (PRK) in active-duty military personnel.
  
  
  METHODS
  Photorefractive keratectomy (6.0-mm ablation zone) was performed on 30 navy/marine personnel(-2.00 to -5.50 diopters [D]; mean, -3.35 D). Glare disability was assessed with a patient questionnaire and measurements of intraocular light scatter and near contrast acuity with glare.
  
  
  RESULTS
  At 1 year, all 30 patients had 20/20 or better uncorrected visual acuity with no loss of best-corrected vision. By cycloplegic refraction, 53% (16/30) of patients were within +/- 0.50 D of emmetropia and 87% (26/30) were within +/- 1.00 D. The refraction (mean +/- standard deviation) was +0.45 +/- 0.56 D (range, -1.00 to 1.63 D). Four patients (13%) had an overcorrection of more than 1 D. Glare testing in the early (1 month) postoperative period demonstrated increased intraocular light scatter (P<0.01) and reduced contrast acuity (with and without glare, (P<0.01). These glare measurements statistically returned to preoperative levels by 3 months (undilated) and 12 months (dilated) postoperatively. Two patients reported moderate to severe visual symptoms (glare, halo, night vision) worsened by PRK. One patient had a decrease in the quality of night vision severe enough to decline treatment in the fellow eye. Intraocular light scatter was increased significantly (>2S D) in this patient after the procedure.
  
  
  CONCLUSIONS
  Photorefractive keratectomy reduced myopia and improved the uncorrected vision acuity of all patients in this study. Refinement of the ablation algorithm is needed to decrease the incidence of hyperopia. Glare disability appears to be a transient event after PRK. However, a prolonged reduction in the quality of vision at night was observed in one patient and requires further study.
authors.affiliation: Department of Ophthalomology and Clinical Investigation, Naval Medical Center, San Diego, CA, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Schallhorn
authors.forename: C L
authors.initials: CL
authors.lastname: Blanton
authors.forename: S E
authors.initials: SE
authors.lastname: Kaupp
authors.forename: J
authors.initials: J
authors.lastname: Sutphin
authors.forename: M
authors.initials: M
authors.lastname: Gordon
authors.forename: H
authors.initials: H
authors.lastname: Goforth
authors.forename: F K
authors.initials: FK
authors.lastname: Butler
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity; D003315:Cornea / Q000502:physiology / Q000601:surgery*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000209:etiology; D054018:Lasers, Excimer; D008027:Light; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000009:adverse effects; D011183:Postoperative Complications; D011379:Prognosis; D012029:Refraction, Ocular; D012542:Scattering, Radiation; D014481:United States; D014786:Vision Disorders / Q000209:etiology; D014792:Visual Acuity; D014945:Wound Healing