title: Cross-linking in progressive keratoconus using an epithelial debridement or intrastromal pocket technique after previous corneal ring segment implantation.
abstract: OBJECTIVE
  To evaluate and compare the clinical and confocal microscopic outcomes achieved with two different procedures for cross-linking (CXL) in eyes with keratoconus: CXL with epithelial debridement and CXL with intrastromal pocket.
  
  
  METHODS
  This retrospective study included 27 eyes of 21 patients (age range: 18 to 53 years) diagnosed with keratoconus who underwent implantation of intracorneal ring segments and CXL with two different techniques: CXL with previous epithelial debridement (classic group, 16 eyes) and CXL with intrastromal pocket for riboflavin infusion (pocket group, 11 eyes). Visual, refractive, topographic, aberrometric, and pachymetric data were evaluated during 12-month follow-up.
  
  
  RESULTS
  No statistically significant differences between the classic and pocket groups were found in postoperative visual acuity (P ≥.71), refraction (P ≥.15), keratometry (P ≥.28), corneal aberrations (P ≥.13), or central pachymetry (P ≥.21). A statistically significant improvement in uncorrected visual acuity found at 3 months postoperatively in both groups (P<.03) was consistent with a change in manifest sphere. Mean keratometric reduction at 12 months was 0.03 diopters (D) in the classic group (P=.55) and 0.40 D in the pocket group (P=.05). No significant changes in corneal higher order aberrations or central corneal thickness were found in either group (P ≥.14).
  
  
  CONCLUSIONS
  Cross-linking surgery with creation of an intrastromal pocket seems to provide similar clinical outcomes compared to the classic CXL technique.
authors.affiliation: Universidad Miguel Hernandez, Spain. jlalio@vissum.com
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alió
authors.forename: Bader T
authors.initials: BT
authors.lastname: Toffaha
authors.forename: David P
authors.initials: DP
authors.lastname: Piñero
authors.forename: Pawel
authors.initials: P
authors.lastname: Klonowski
authors.forename: Jaime
authors.initials: J
authors.lastname: Javaloy
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism; D003319:Corneal Stroma / Q000187:drug effects / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000008:administration & dosage*; D003646:Debridement; D020878:Device Removal; D018450:Disease Progression; D019573:Epithelium, Corneal / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D018613:Microscopy, Confocal; D008875:Middle Aged; D017319:Photosensitizing Agents / Q000008:administration & dosage; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D012256:Riboflavin / Q000008:administration & dosage; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin