title: Multiple photorefractive keratectomy retreatments for myopia.
abstract: OBJECTIVE
  To examine the outcome of multiple photorefractive keratectomy retreatments by the excimer laser on eyes treated for myopia and myopic astigmatism.
  
  
  METHODS
  We present 980 of 1218 (80%) consecutive eyes treated with a VISX 20/20 excimer laser that were available for follow-up. Thirteen eyes of 13 individuals were retreated twice using the same VISX excimer laser because of refractive regression. Epithelium was mechanically removed in the initial treatment and subsequent retreatment of all the eyes. No increased difficulty was noted upon removing the epithelium on subsequent retreatments. The aim in both the initial and subsequent treatments was to correct 100% of the refractive error.
  
  
  RESULTS
  Eyes with higher amounts of myopia and astigmatism were more likely to require multiple retreatments. Seven eyes (54%) attained a spectacle-corrected visual acuity of 20/20 or better. Twelve eyes (92%) attained a spectacle-corrected visual acuity of 20/40 or greater following the second retreatment. The amount of astigmatism corrected was improved in 10 of the 13 eyes with an average improvement of 1.90 D of cylinder. Only one patient experienced a haze score of 3 or more following retreatment.
  
  
  CONCLUSIONS
  There is a subgroup of patients who require multiple PRK retreatments for myopic regression. A good visual outcome may be obtained with minimal haze.
authors.affiliation: Department of Ophthalmology, Royal Victorian Eye and Ear Hospital, University of Melbourne, Victoria, Australia.
authors.forename: H
authors.initials: H
authors.lastname: Higa
authors.forename: T
authors.initials: T
authors.lastname: Couper
authors.forename: D I
authors.initials: DI
authors.lastname: Robinson
authors.forename: H R
authors.initials: HR
authors.lastname: Taylor
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000601:surgery; D003315:Cornea / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy; D012008:Recurrence; D012086:Reoperation; D016896:Treatment Outcome; D014792:Visual Acuity