title: Excimer retreatment for scarring and regression after photorefractive keratectomy for myopia.
abstract: OBJECTIVE
  Scarring associated with regression of refractive effect can occur after photorefractive keratectomy (PRK) for myopia. The experience of treating these complications is reported.
  
  
  METHODS
  Eighteen of 285 eyes (6.3%) were retreated with the excimer laser. Age, sex, preoperative primary treatment keratometry, pre-primary treatment, pre-retreatment and post-retreatment spherical equivalents, best corrected and uncorrected visual acuities were recorded and analysed.
  
  
  RESULTS
  At 6 months post-retreatment, the mean spherical equivalent was -2.07 dioptres (D) (SD 4.60 D). This spherical equivalent persisted in eyes followed for 12 months (-2.85D, SD 4.09 D). Nine of 18 eyes (50%) had uncorrected visual acuity of 6/12 (20/40) or better. If retreatment was undertaken within 6.5 months of the initial PRK, then scarring was likely to recur (p = 0.035). Nine of 10 eyes (90%) which had a retreatment spherical equivalent less than two thirds of their primary treatment spherical equivalent were within plus or minus 1.25D from emmetropia after retreatment. Four of 11 eyes (36%) followed for 12 months after retreatment rescarred with further regression.
  
  
  CONCLUSIONS
  The data showed that eyes with scarring and regression of myopia should not be treated with PRK within 6 months of the initial procedure. Eyes with the highest percentage of regression towards their initial myopia tend to have a poor response to retreatment.
authors.affiliation: Sydney Refractive Surgery Centre, St Leonards, New South Wales, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Sutton
authors.forename: R S
authors.initials: RS
authors.lastname: Kalski
authors.forename: M A
authors.initials: MA
authors.lastname: Lawless
authors.forename: C
authors.initials: C
authors.lastname: Rogers
mesh_terms: D000328:Adult; D002921:Cicatrix / Q000601:surgery; D003315:Cornea / Q000601:surgery*; D005260:Female; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D011183:Postoperative Complications / Q000601:surgery*; D012008:Recurrence; D012029:Refraction, Ocular; D012086:Reoperation; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity