title: Complication and failure rates after corneal crosslinking.
abstract: OBJECTIVE
  To evaluate the complication rate of corneal crosslinking (CXL) for primary keratectasia and to develop recommendations for avoiding complications.
  
  
  METHODS
  Institut für Refraktive und Ophthalmo-Chirurgie, Zurich, Switzerland.
  
  
  METHODS
  In a prospective study, eyes with verified progressive keratectasia had standard CXL. Preoperative and 6- and 12-month postoperative examinations included corrected distance visual acuity (CDVA), slitlamp evaluation, applanation tonometry, and Scheimpflug imaging (Pentacam). Statistical analysis included analysis of variance and the Mann-Whitney U test to detect risk factors for complications.
  
  
  RESULTS
  The study evaluated 117 eyes of 99 patients; approximately 90% completed the 12-month follow-up. The complication rate (percentage of eyes losing 2 or more Snellen lines) was 2.9% (95% confidence interval, 0.6%-8.5%). The failure rate of CXL (percentage of eyes with continued progression) was 7.6%. Age older than 35 years and a preoperative CDVA better than 20/25 were identified as significant risk factors for complications. A high preoperative maximum keratometry (K) reading was a significant risk factor for failure. Sterile infiltrates were seen in 7.6% of eyes and central stromal scars, in 2.8%.
  
  
  CONCLUSIONS
  Results indicate that changing the inclusion criteria may significantly reduce the complications and failures of CXL. A preoperative maximum K reading less than 58.00 diopters may reduce the failure rate to less than 3%, and restricting patient age to younger than 35 years may reduce the complication rate to 1%.
authors.affiliation: From Institut für Refraktive und Ophthalmo-Chirurgie, Zürich, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Koller
authors.forename: Michael
authors.initials: M
authors.lastname: Mrochen
authors.forename: Theo
authors.initials: T
authors.lastname: Seiler
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism*; D003319:Corneal Stroma / Q000378:metabolism* / Q000503:physiopathology; D019781:Corneal Topography; D004108:Dilatation, Pathologic / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D010778:Photochemotherapy / Q000009:adverse effects*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011183:Postoperative Complications; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012256:Riboflavin / Q000627:therapeutic use; D012307:Risk Factors; D017211:Treatment Failure; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology
chemical_list: D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin