title: A prospective study of the prevalence of corneal surface disease in dogs receiving prophylactic topical lubrication under general anesthesia.
abstract: OBJECTIVE
  To identify the prevalence of corneal ulceration in dogs receiving prophylactic gel lubrication under general anesthesia (GA).
  
  
  METHODS
  An ophthalmic examination was performed before premedication and 24 h after GA in 100 dogs (199 eyes) undergoing nonophthalmic procedures. Individuals with known pre-existing ocular surface conditions were excluded. An ocular lubricating gel containing carmellose sodium was applied by the anesthetist at induction and every 2-4 h until extubation. Logistic regression analysis was used to calculate risk factors for ulcerative disease, including signalment, length of GA, patient position, procedure performed, pre-, and post-GA ophthalmic examination findings and admitting service. A Wilcoxon rank sum test compared pre- and post-GA Schirmer tear test-1 (STT-1) values.
  
  
  RESULTS
  One dog (0.5% of total eyes) developed fluorescein stain uptake consistent with superficial corneal ulceration that resolved within 48 h with supportive treatment. Twenty-five (18.6% of total eyes) developed a faint, patchy corneal uptake of stain in the axial cornea that was consistent with epithelial erosion. All erosions resolved with lubrication 24 h later. The decrease in STT-1 readings at 24 h post-GA was statistically significant from those pre-GA (P < 0.001). No significant risk factors for corneal erosion/ulceration were identified.
  
  
  CONCLUSIONS
  The results of this study show that a basic protocol of prophylactic lubrication during GA was associated with a low prevalence of corneal ulceration but a higher prevalence of epithelial erosion. In addition, the study supports the need for post-GA corneal examination.
authors.affiliation: The Royal Veterinary College, Department of Clinical Science and Services, Hawkshead lane, North Mymms, Herts, AL9 7TA, UK.
authors.forename: Charlotte
authors.identifier: http://orcid.org/0000-0001-9974-1244
authors.initials: C
authors.lastname: Dawson
authors.affiliation: The Royal Veterinary College, Department of Clinical Science and Services, Hawkshead lane, North Mymms, Herts, AL9 7TA, UK.
authors.forename: Rick F
authors.initials: RF
authors.lastname: Sanchez
mesh_terms: D000768:Anesthesia, General / Q000009:adverse effects / Q000662:veterinary*; D000818:Animals; D002266:Carboxymethylcellulose Sodium / Q000627:therapeutic use*; D003316:Corneal Diseases / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*; D004283:Dog Diseases / Q000453:epidemiology / Q000209:etiology*; D004285:Dogs; D065346:Lubricant Eye Drops / Q000008:administration & dosage / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000517:prevention & control / Q000662:veterinary; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D014456:Ulcer / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*
chemical_list: D065346:Lubricant Eye Drops; D002266:Carboxymethylcellulose Sodium
keywords: Schirmer tear test-1; corneal ulceration; dogs; general anesthesia; risk factors; topical lubrication