title: Corneal collagen cross-linking with riboflavin and ultraviolet-A irradiation in patients with thin corneas.
abstract: OBJECTIVE
  To report the outcomes after corneal collagen cross-linking (CXL) treatment with riboflavin and ultraviolet-A (UVA) irradiation in patients with thin corneas (minimum corneal thickness less than 400 μm after epithelial removal and before riboflavin instillation).
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  Twelve patients (14 eyes, with minimum corneal thickness less than 400 μm after epithelial removal) were included in the study. All patients underwent riboflavin-UVA-induced CXL using the standard CXL (Dresden) protocol. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) (decimal scale), manifest refraction (diopters, D), and topography were evaluated at baseline and at 1, 3, 6, and 12 months follow-up. Images of the endothelium were acquired with a modified confocal scanning laser ophthalmoscope.
  
  
  RESULTS
  No intraoperative or postoperative complications were observed in this patient series. Mean minimum preoperative corneal thickness at the apex of the cone after epithelial removal and before riboflavin instillation was 373.92 ± 22.92 μm (range 340-399 μm). UDVA and CDVA improved from 0.25 ± 0.15 and 0.40 ± 0.20 to 0.27 ± 0.17 and 0.49 ± 0.20 respectively at the last follow-up examination. There was a reduction of the mean keratometry readings from 51.99 ± 5.57 D to 49.33 ± 4.82 D at the last follow-up. A significant decrease of endothelial cell density was observed (preoperative: 2733 ± 180 cells/mm(2) [range 2467-3016], last follow-up visit: 2441 ± 400 cells/mm(2) [range 1448-2920], P < .01).
  
  
  CONCLUSIONS
  CXL in thin corneas with minimum corneal thickness less than 400 μm after epithelial removal seems to result in a significant endothelial cell density decrease postoperatively. This finding was not related to other intraoperative or postoperative complications.
authors.affiliation: Institute of Vision and Optics, University of Crete, Heraklion, Crete, Greece. kymionis@med.uoc.gr
authors.forename: George D
authors.initials: GD
authors.lastname: Kymionis
authors.forename: Dimitra M
authors.initials: DM
authors.lastname: Portaliou
authors.forename: Vasilios F
authors.initials: VF
authors.lastname: Diakonis
authors.forename: George A
authors.initials: GA
authors.lastname: Kounis
authors.forename: Sophia I
authors.initials: SI
authors.lastname: Panagopoulou
authors.forename: Michael A
authors.initials: MA
authors.lastname: Grentzelos
mesh_terms: D000328:Adult; D002452:Cell Count; D003094:Collagen / Q000378:metabolism*; D055954:Corneal Endothelial Cell Loss / Q000175:diagnosis / Q000209:etiology; D003319:Corneal Stroma / Q000378:metabolism* / Q000473:pathology; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D018613:Microscopy, Confocal; D009887:Ophthalmoscopy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D012256:Riboflavin / Q000627:therapeutic use*; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin