title: Persistent corneal edema after collagen cross-linking for keratoconus.
abstract: OBJECTIVE
  To present a new complication of persistent corneal edema after collagen cross-linking (CXL) in keratoconus patients.
  
  
  METHODS
  Retrospective case series of postoperative corneal edema after CXL.
  
  
  METHODS
  study population: All patients who underwent CXL treatment with subsequent corneal edema. Patients with stromal haze were excluded. intervention: The CXL treatments used the Dresden protocol with corneal thickness of more than 400 μm after epithelium was removed. main outcome measure: The resolution of corneal edema after surgery.
  
  
  RESULTS
  Postoperative corneal edema was identified in 10 (2.9%) of 350 patients who were followed up for a mean of 14 ± 4 months. The edema started on postoperative day 1 (10/10) and increased for 3 weeks. Additional findings included: deep vascularization (2 eyes; 20%), iris atrophy (6 eyes; 60%), pigment dispersion (5 eyes; 50%), persistent epithelial defect (3 eyes; 30%), and infectious keratitis (1 eye; 10%). Specular microscopy was unsuccessful, but the fellow untreated eyes had normal endothelial counts. Intraocular pressure and lenticular evaluations were normal. Corneal edema improved in 4 patients and resolved in 1 patient. In these 5 patients, the logarithm of the minimal angle of resolution best-corrected visual acuity was 0.5 ± 0.18. Penetrating keratoplasty was offered to 5 patients when improvement plateaued at 3 months, but only 2 patients underwent penetrating keratoplasty.
  
  
  CONCLUSIONS
  CXL is a safe and effective procedure with few known side effects. This case series reports the possibility of corneal endothelial damage with visually significant corneal edema after CXL treatment. Based on the extent of endothelial damage, patients may require penetrating keratoplasty.
authors.affiliation: Cornea Centre, Chandigarh, India.
authors.forename: Ashok
authors.initials: A
authors.lastname: Sharma
authors.forename: Jennifer Marie
authors.initials: JM
authors.lastname: Nottage
authors.forename: Kanish
authors.initials: K
authors.lastname: Mirchia
authors.forename: Rajan
authors.initials: R
authors.lastname: Sharma
authors.forename: Kanwar
authors.initials: K
authors.lastname: Mohan
authors.forename: Verinder Singh
authors.initials: VS
authors.lastname: Nirankari
mesh_terms: D000293:Adolescent; D000328:Adult; D001284:Atrophy; D002452:Cell Count; D003094:Collagen / Q000378:metabolism*; D015715:Corneal Edema / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007498:Iris / Q000473:pathology; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011183:Postoperative Complications; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D013997:Time Factors; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin