title: Refractive and topographic results of benzalkonium chloride-assisted transepithelial crosslinking.
abstract: OBJECTIVE
  To evaluate the effect of benzalkonium chloride-assisted (BAC) transepithelial collagen crosslinking (CXL) in eyes with progressive keratoconus and a minimum follow-up of 6 months.
  
  
  METHODS
  Department of Ophthalmology, Antwerp University Hospital, Antwerp, Belgium.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Eyes with progressive keratoconus had CXL treatment without epithelial debridement. The standard CXL irradiation was preceded by instillation of proparacaine drops 0.5% preserved with BAC 0.005% every 5 minutes for 30 minutes. Selected parameters of refraction assessed by Placido disk (Eyesys) and Scheimpflug (Pentacam) examinations were compared before CXL and after CXL at 6, 12, and 18 months.
  
  
  RESULTS
  The study enrolled 53 eyes of 38 patients. Sphere, cylinder, as well as maximum keratometry (K max) simulated K values (steep, flat, astigmatism), and refractive power values (steep, flat, astigmatism) measured using the Placido disk device remained stable over the 18-month follow-up. Only corrected distance visual acuity showed a statistically significant improvement at 6 months and 12 months. The Scheimpflug device measurements of maximum K and pachymetry at the thinnest point showed statistically significant progression throughout the study. No patient developed corneal haze or other complications.
  
  
  CONCLUSIONS
  Transepithelial CXL using proparacaine drops 0.5% preserved with BAC 0.005% was less effective than standard CXL in stabilizing progressive keratoconus.
authors.affiliation: Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium. carina.koppen@uza.be
authors.forename: Carina
authors.initials: C
authors.lastname: Koppen
authors.forename: Kristien
authors.initials: K
authors.lastname: Wouters
authors.forename: Danny
authors.initials: D
authors.lastname: Mathysen
authors.forename: Jos
authors.initials: J
authors.lastname: Rozema
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Tassignon
mesh_terms: D000293:Adolescent; D000328:Adult; D001548:Benzalkonium Compounds / Q000627:therapeutic use*; D002648:Child; D015331:Cohort Studies; D003094:Collagen / Q000378:metabolism; D003319:Corneal Stroma / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D018450:Disease Progression; D019573:Epithelium, Corneal / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011310:Preservatives, Pharmaceutical / Q000627:therapeutic use*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology
chemical_list: D001548:Benzalkonium Compounds; D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D011310:Preservatives, Pharmaceutical; D003094:Collagen; D012256:Riboflavin