title: Permanent corneal haze after riboflavin-UVA-induced cross-linking in keratoconus.
abstract: OBJECTIVE
  Retrospective evaluation of haze development after riboflavin-ultraviolet (UV) A-induced corneal collagen cross-linking (CXL).
  
  
  METHODS
  One hundred sixty-three eyes of 127 patients with stage 1-3 keratoconus according to Krumeich's classification were included in this retrospective analysis. Follow-up was 1 year. Preoperatively and at all follow-up examinations uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), slit-lamp microscopic findings, corneal topography, and corneal thickness were recorded.
  
  
  RESULTS
  At 1 year after CXL, 149 (91.4%) eyes of 114 patients had a clear cornea without stromal haze (control group), whereas 14 eyes (8.6%) of 13 patients developed clinically significant stromal haze (haze group). Preoperatively, the mean keratometry (K) value of the apex was 62.1+/-13.8 diopters (D) in the control group and 71.1+/-13.2 D in the haze group (P=.02). The mean corneal thickness before the procedure was 478.1+/-52.4 mum in the control group and 420.0+/-33.9 mum in the haze group (P=.001). Uncorrected visual acuity and BSCVA, which were similar between groups preoperatively (P=.59 and P=.75, respectively), were improved in the control group (P=.023 and P=.001, respectively), but reduced in the haze group (P=.012 and P=.004, respectively) postoperatively.
  
  
  CONCLUSIONS
  The parameters defining the stage of keratoconus, such as K-value and corneal thickness, could be considered predicting factors for possible development of corneal haze after riboflavin-UVA-induced CXL. Advanced keratoconus should be considered at higher risk of haze development after CXL due to low corneal thickness and high corneal curvature.
authors.affiliation: Department of Ophthalmology, Carl Gustav Carus University Hospital, Dresden, Germany. Raiskup@uniklinikum-dresden.de
authors.forename: Frederik
authors.initials: F
authors.lastname: Raiskup
authors.forename: Anne
authors.initials: A
authors.lastname: Hoyer
authors.forename: Eberhard
authors.initials: E
authors.lastname: Spoerl
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D003318:Corneal Opacity / Q000175:diagnosis / Q000209:etiology*; D003319:Corneal Stroma / Q000378:metabolism / Q000473:pathology; D019781:Corneal Topography; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D010778:Photochemotherapy / Q000009:adverse effects*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011183:Postoperative Complications; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use*; D014466:Ultraviolet Rays; D014792:Visual Acuity
chemical_list: D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin