title: Comparison of the Effect of Epithelial Removal by Transepithelial Phototherapeutic Keratectomy or Manual Debridement on Cross-linking Procedures for Progressive Keratoconus.
abstract: OBJECTIVE
  To compare the visual, refractive, keratometric, topographic, and pachymetric outcomes of corneal collagen cross-linking (CXL) for progressive keratoconus following epithelial removal by transepithelial phototherapeutic keratectomy (PTK) or manual debridement.
  
  
  METHODS
  In this analysis, 339 eyes (78% male, 22% female) that had undergone CXL following manual epithelial debridement (n = 180) or ablation via PTK (n = 159) were evaluated preoperatively and at 6, 12, and 24 months postoperatively for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), maximum corneal keratometry, pachymetry, and spherical equivalent. The data were analyzed in a t test to evaluate the relative efficacy of each epithelial removal procedure.
  
  
  RESULTS
  Manual epithelial debridement and ablation via PTK produce equivalent changes for all variables at each time interval with the exception of maximum corneal keratometry at 6 months postoperatively, for which PTK exhibited a significantly improved (flatter) result. This difference was present but not statistically significant at 12 and 24 months postoperatively.
  
  
  CONCLUSIONS
  Prior to CXL, both manual epithelial debridement and ablation via PTK result in equivalent visual, refractive, and keratometric outcomes up to 24 months postoperatively. [J Refract Surg. 2016;32(10):699-704.].
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Gaster
authors.forename: J
authors.initials: J
authors.lastname: Ben Margines
authors.forename: David N
authors.initials: DN
authors.lastname: Gaster
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Li
authors.forename: Yaron S
authors.initials: YS
authors.lastname: Rabinowitz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003094:Collagen / Q000378:metabolism; D003319:Corneal Stroma / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents; D003646:Debridement / Q000379:methods*; D019573:Epithelium, Corneal / Q000601:surgery*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D054018:Lasers, Excimer / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D018903:Photorefractive Keratectomy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin