title: Treatment of bullous keratopathy with corneal collagen cross-linking in two dogs.
abstract: OBJECTIVE
  Corneal collagen cross-linking with riboflavin and UV-A (CXL) decreases corneal oedema and increases visual acuity in human patients with bullous keratopathy. Presumed mechanisms are an increase in collagen packing density and a reduction in stromal swelling pressure. We present two cases in which CXL was used to treat bullous keratopathy in dogs.
  
  
  METHODS
  Four eyes of two dogs with painful bullous keratopathy-induced corneal erosions that were resistant to prior therapy were treated with CXL. Both corneas of the second patient were dehydrated to ± 400 μm corneal thickness using topical 70% glycerol solution immediately prior to CXL. Follow-up included slit-lamp examination, fluorescein staining and photographic documentation in both cases and high-resolution ultrasound examination in the second patient.
  
  
  RESULTS
  All four eyes were comfortable and fluorescein negative at 1-week post-CXL and remained so for the rest of the follow-up period (17.5 months for case 1 and 6 months for case 2). The owner of the first patient reported a less oedematous cornea and improvement in vision that lasted for 6 months. Despite a reported lack of improvement in vision in the second patient, corneal thickness initially decreased, but was back at baseline thickness at the 4-month recheck.
  
  
  CONCLUSIONS
  Similar to humans, CXL might become a useful treatment option for bullous keratopathy-induced therapy-resistant corneal erosions in dogs. Patient comfort was greatly improved, but corneal thickness decrease was not as long-lasting as reported for humans. The presently used protocols might need modification to fit the dog cornea.
authors.affiliation: Equine Department, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Pot
authors.forename: Nicolin S
authors.initials: NS
authors.lastname: Gallhöfer
authors.forename: Ladina
authors.initials: L
authors.lastname: Walser-Reinhardt
authors.forename: Farhad
authors.initials: F
authors.lastname: Hafezi
authors.forename: Bernhard M
authors.initials: BM
authors.lastname: Spiess
mesh_terms: D000818:Animals; D001768:Blister / Q000628:therapy / Q000662:veterinary*; D003094:Collagen; D003316:Corneal Diseases / Q000628:therapy / Q000662:veterinary*; D004283:Dog Diseases / Q000628:therapy*; D004285:Dogs; D005260:Female; D008297:Male; D012256:Riboflavin / Q000008:administration & dosage / Q000494:pharmacology*; D014467:Ultraviolet Therapy / Q000662:veterinary*
chemical_list: D003094:Collagen; D012256:Riboflavin
keywords: bullous keratopathy; cornea; corneal collagen cross-linking; dog; endothelial decompensation; oedema