title: Clinical features of subepithelial layer irregularities of cornea.
abstract: OBJECTIVE
  To illustrate surgical outcomes of subepithelial irregularities that were identified incidentally during laser refractive surgery.
  
  
  METHODS
  The study group consisted of 406 patients who underwent 787 surface ablation refractive surgeries. Ophthalmologic evaluations were performed before each procedure and at 1, 3 and 6 months post-operatively. Subepithelial irregularities were evaluated by analyzing still photographs captured from video recordings. Sizes and locations were determined by a calibrated scale located at the major axis of the tracking system's reticle.
  
  
  RESULTS
  Subepithelial irregularities were identified in 27 eyes during 787 surface ablation refractive surgeries. Most of the subepithelial irregularities did not show any abnormalities in the wavefront aberrometer. However, one case with diameter greater than 1.00 mm and one case of clustered multiple subepithelial irregularities with moderate size were corresponded significant coma (Z31) and increased higher order aberration (HOA) in the HOA gradient map.
  
  
  CONCLUSIONS
  Corneal subepithelial irregularities may be related to problems that include significantly increased localized HOA and remaining permanent subepithelial opacity. Subepithelial irregularity should be considered even if the surface of the cornea is intact and there are no specific findings measured by corneal topography.
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine , Seoul , Korea.
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Lee
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Gye
authors.forename: Chul Young
authors.initials: CY
authors.lastname: Choi
mesh_terms: D057128:Aberrometry; D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000601:surgery*; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000175:diagnosis* / Q000601:surgery; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
keywords: Cornea; Epi-LASIK; PRK; higher order aberration; subepithelial irregularity