title: Effective corneal collagen crosslinking in advanced cases of progressive keratoconus.
abstract: OBJECTIVE
  To evaluate the 1-year results of corneal collagen crosslinking (CXL) in mild to moderate cases and advanced cases of progressive keratoconus.
  
  
  METHODS
  Department of Ophthalmology, University Medical Center Utrecht, the Netherlands.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Eyes with progressive keratoconus had CXL between January 2010 and April 2011. Patients were divided into 2 subgroups as follows: Group 1, mild to moderate keratoconus with a preoperative maximum keratometry (K) of less than 58.0 diopters (D), and Group 2, advanced keratoconus with a maximum K of 58.0 D or more. Visual acuity, refraction, and elevation-based topography were evaluated at baseline and 12 months after CXL.
  
  
  RESULTS
  The study comprised 53 eyes of 42 patients. In the overall group, progression was halted in 48 eyes (91%). The CXL-induced corneal flattening occurred in 11 (42%) of 26 eyes in Group 1 and 20 (74%) of 27 eyes in Group 2. Five of 7 keratoconus indices improved 12 months after CXL. The failure rate was comparable in the subgroups (3 eyes in Group 1, 2 eyes in Group 2). No major complications occurred in either subgroup.
  
  
  CONCLUSIONS
  Stabilization after CXL was achieved in mild to moderate cases and advanced cases of progressive keratoconus. The amount of failure was comparable in the 2 subgroups. The CXL-induced flattening was more pronounced in the advanced subgroup.
authors.affiliation: Department of Ophthalmology, University Medical Center Utrecht, the Netherlands.
authors.forename: Frea
authors.initials: F
authors.lastname: Sloot
authors.forename: Nienke
authors.initials: N
authors.lastname: Soeters
authors.forename: Rikkert
authors.initials: R
authors.lastname: van der Valk
authors.forename: Nayyirih G
authors.initials: NG
authors.lastname: Tahzib
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D003094:Collagen / Q000378:metabolism*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011379:Prognosis; 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