title: [Multiple factors analysis of myopic regression after photorefractive keratectomy].
abstract: OBJECTIVE
  To investigate myopic regression after excimer laser photorefractive keratectomy(PRK) in patients with myopia.
  
  
  METHODS
  PRK was performed to correct myopia errors from 1.00 D to 16.00 D diopters on 214 myopia eyes(121 patients). All eyes were divided into two groups: group I--1.00 D(-)-6.00 D (124 eyes), group II--6.25 D(-)-16.00 D(90 eyes). All the patients were followed up for two years.
  
  
  RESULTS
  A Significant positive correlation was found between the regression and the extents of attempted correction. The rate of regression in mild to moderate myopia group was 9.7% while in highter group it was 27.8% (P < 0.005). The rate of regression of older age group in lighter myopia group was highter than that in younger case (P < 0.005). Relatively severe haze under the corneal epithelium often accompanies the regression.
  
  
  CONCLUSIONS
  The main factors which caused the myopia regression after PRK was the extent of attempted correction, patients' age and corneal haze.
authors.affiliation: Ophthalmiclaser Center, Xiangya Hospital, Hunan Medical University, Changsha 410008, China.
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.forename: P
authors.initials: P
authors.lastname: Huang
authors.forename: X
authors.initials: X
authors.lastname: Xia
authors.forename: P
authors.initials: P
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D012029:Refraction, Ocular; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity