title: Prospective longitudinal study of corneal collagen cross-linking in progressive keratoconus.
abstract: BACKGROUND
  Collagen cross-linking has been reported to be effective in treating progressive keratoconus, and this study aims to evaluate the long-term efficacy of this procedure.
  
  
  METHODS
  Prospective longitudinal interventional study of patients with progressive keratoconus who underwent cross-linking in a tertiary referral hospital.
  
  
  METHODS
  Thirty-five patients (51 eyes) who underwent cross-linking with a mean follow-up of 14.38 ± 9.36 months (range 6-48) were compared with a control group of 25 fellow eyes that did not undergo the procedure.
  
  
  METHODS
  Cross-linking was performed using 0.1% riboflavin (in 20% dextran T500) and ultraviolet A irradiation (370 nm, 3 mW/cm(2) , 30 min).
  
  
  METHODS
  Maximum keratometry in dioptres, logMAR best spectacle-corrected visual acuity, cylindrical power, manifest refraction spherical equivalent and central corneal thickness.
  
  
  RESULTS
  Analysis of the treated group demonstrated a significant flattening of maximum keratometry by 0.96 ± 2.33 dioptres (P = 0.005) and a significant improvement in visual acuity by 0.05 ± 0.13 logMAR (P = 0.04). In the control group, maximum keratometry increased significantly by 0.43 ± 0.85 dioptres (P = 0.05), and visual acuity decreased by mean 0.05 ± 0.14 (P = 0.2). No statistical differences were noted regarding cylindrical power, spherical equivalent or corneal thickness in both groups.
  
  
  CONCLUSIONS
  Results indicate that corneal collagen cross-linking using riboflavin and ultraviolet A is effective as a therapeutic option in cases of progressive keratoconus by reducing the corneal curvature and by improving the visual acuity in these patients.
authors.affiliation: Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia. deepa.viswanathan@students.mq.edu.au
authors.forename: Deepa
authors.initials: D
authors.lastname: Viswanathan
authors.forename: John
authors.initials: J
authors.lastname: Males
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D008137:Longitudinal Studies; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; 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
keywords: collagen cross-linking; keratoconus; maximum keratometry