title: Epithelium-off corneal collagen cross-linking versus transepithelial cross-linking for pediatric keratoconus.
abstract: OBJECTIVE
  To compare efficiency and safety of epithelium-off corneal cross-linking (CXL) and transepithelial cross-linking (TE-CXL) in pediatric patients with progressive keratoconus.
  
  
  METHODS
  Uncorrected and corrected visual acuity, corneal topography and pachymetry (Pentacam; Oculus Pentacam), and in vivo confocal microscopy (HRT II, Rostock Cornea Module, Heidelberg Engineering, Heidelberg, Germany) were evaluated at baseline and at 3, 6, and 12 months.
  
  
  RESULTS
  In the epithelium-off CXL group (19 patients, 23 eyes; mean age, 14.75 ± 2.1 years), a significant improvement at month 12 was present for Kmax [-1.11 diopters (D), P = 0.01], Kmin (-3.2 D, P = 0.001), mean K (-1.47 D, P = 0.01), surface asymmetry index (-0.64 D, P = 0.001), inferior-superior symmetry index (-0.54 D, P = 0.01), index of height asymmetry (-2.97, P = 0.03), and anterior elevation at the thinnest location (-2.82 D, P = 0.01) and at the apex (-2.27 D, P = 0.01). Postoperative corneal edema lasted 3 months in 16 eyes (69.5%) and more than 6 months in 2 eyes (8.7%). In the TE-CXL group (10 patients, 14 eyes; mean age, 15 ± 4.2 years), a significant improvement at month 12 was present for Kmax (-1.14 D, P = 0.02), Kmin (-2.04 D, P = 0.01), mean K (-1.63 D, P = 0.01), surface asymmetry index (-0.86 D, P = 0.001), inferior-superior symmetry index (-0.55 D, P = 0.001), index of height asymmetry (-2.95, P = 0.01), and anterior elevation at the thinnest location (-2.96 D, P = 0.01) and at the apex (-2.19 D, P = 0.01). No postoperative corneal edema after TE-CXL was observed. Changes at month 12 from baseline were not significantly different between the 2 groups (P > 0.05). TE-CXE was significantly less painful than epithelium-off CXL.
  
  
  CONCLUSIONS
  In pediatric patients with progressive keratoconus, TE-CXL was less painful, provided similar effectiveness and fewer complications than epithelium-off CXL at 12-month follow-up.
authors.affiliation: Eye Department, University Federico II, Naples, Italy.
authors.forename: Adriano
authors.initials: A
authors.lastname: Magli
authors.forename: Raimondo
authors.initials: R
authors.lastname: Forte
authors.forename: Achille
authors.initials: A
authors.lastname: Tortori
authors.forename: Luigi
authors.initials: L
authors.lastname: Capasso
authors.forename: Giovanni
authors.initials: G
authors.lastname: Marsico
authors.forename: Elena
authors.initials: E
authors.lastname: Piozzi
mesh_terms: D000293:Adolescent; D002648:Child; D003094:Collagen / Q000378:metabolism*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism*; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D003646:Debridement; D019573:Epithelium, Corneal / Q000601:surgery*; D058447:Eye Pain / Q000175:diagnosis; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D018613:Microscopy, Confocal; D010147:Pain Measurement; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin