title: Posterior linear stromal haze formation after simultaneous photorefractive keratectomy followed by corneal collagen cross-linking.
abstract: OBJECTIVE
  To report the development of posterior linear stromal haze after simultaneous photorefractive keratectomy (PRK) followed by corneal collagen cross-linking (CXL).
  
  
  METHODS
  Combined simultaneous customized PRK followed by corneal collagen cross-linking was performed in 23 patients (28 eyes) with keratoconus. Corneas were examined biomicroscopically and by means of confocal microscopy before surgery and 1, 3, 6, 9, and 12 months after surgery.
  
  
  RESULTS
  Posterior linear stromal haze was observed clinically (slit lamp biomicroscopy) one month after surgery in 13 of 28 eyes (46.42%). No corneal edema or anterior haze formation was evident. Confocal microscopy revealed in those 13 eyes a hyperreflective area at the level of the posterior stroma 1 month after combined treatment. Both slit lamp examination and corneal confocal microscopy follow-up demonstrated a gradual anterior movement and a decrease in reflectance of this finding. At 12 months this posterior linear stromal haze, despite its anterior movement and decreased density, did not completely disappear at slit lamp and confocal microscopy analysis.
  
  
  CONCLUSIONS
  Posterior linear stromal haze formation may appear after simultaneous PRK followed by CXL in patients with keratoconus. This finding seems to gradually become less dense and slowly moves toward the anterior stroma.
authors.affiliation: Institute of Vision and Optics, University of Crete Medical School, Crete, Greece.
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: Georgios A
authors.initials: GA
authors.lastname: Kontadakis
authors.forename: Maria S
authors.initials: MS
authors.lastname: Krasia
authors.forename: Anastasios G
authors.initials: AG
authors.lastname: Papadiamantis
authors.forename: Efekan
authors.initials: E
authors.lastname: Coskunseven
authors.forename: Aristofanis I
authors.initials: AI
authors.lastname: Pallikaris
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D003131:Combined Modality Therapy; D003318:Corneal Opacity / Q000175:diagnosis / Q000209:etiology*; D003319:Corneal Stroma / Q000378:metabolism / Q000473:pathology*; D019781:Corneal Topography; D003432:Cross-Linking Reagents; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy / Q000601:surgery / Q000628:therapy*; D054018:Lasers, Excimer / Q000627:therapeutic use; D008297:Male; D018613:Microscopy, Confocal; D010778:Photochemotherapy; D018903:Photorefractive Keratectomy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011183:Postoperative Complications; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen