title: Comparison of gonioscopy and ultrasound biomicroscopy for evaluating the iridocorneal angle in dogs.
abstract: OBJECTIVE
  To compare iridocorneal angle grading systems on the basis of gonioscopy and ultrasound biomicroscopy (UBM).
  
  
  METHODS
  Original cross-sectional observational study.
  
  
  METHODS
  22 dogs.
  
  
  METHODS
  Gonioscopy, goniophotography, and UBM were performed on 38 eyes from dogs without clinical evidence of glaucoma in the eyes examined.
  
  
  RESULTS
  Predominant gonioscopic grades derived from goniophotographs were considered normal (n = 26) and mild (12). Ultrasound biomicroscopy angle measurements ranged from 16 to 38 degrees (mean +/- SD, 26.2 +/- 4.5 degrees). Ciliary clefts depicted on UBM images were graded as open (n = 4), compact/narrow (23), and closed (11). Significant differences were not found between UBM-derived ciliary cleft grades and goniophotography-derived dysgenesis grades, nor between UBM-derived ciliary cleft grades and subjective gonioscopic grades.
  
  
  CONCLUSIONS
  Because gonioscopy allows evaluation of the anterior face of the ciliary cleft, whereas UBM provides cross-sectional information of the iridocorneal filtration angle, UBM may yield more information regarding pathogenesis and prognosis of, and preferred management approaches to, glaucoma. Ultrasound biomicroscopy may also be useful as a predictor of glaucoma or to diagnose early stages of glaucoma.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Gibson
authors.forename: S M
authors.initials: SM
authors.lastname: Roberts
authors.forename: G A
authors.initials: GA
authors.lastname: Severin
authors.forename: P F
authors.initials: PF
authors.lastname: Steyn
authors.forename: R H
authors.initials: RH
authors.lastname: Wrigley
mesh_terms: D000818:Animals; D002924:Ciliary Body / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000175:diagnosis; D004285:Dogs / Q000033:anatomy & histology*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000662:veterinary; D006068:Gonioscopy / Q000662:veterinary; D007498:Iris / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D012016:Reference Values; D014463:Ultrasonography