title: Progression of pectinate ligament dysplasia over time in two populations of Flat-Coated Retrievers.
abstract: OBJECTIVE
  Two of the authors (DG, BS) independently observed that a number of Flat-Coated Retrievers (FCRs) previously unaffected by pectinate ligament dysplasia (PLD) appeared to develop the condition later in life. This study was instigated to investigate progression of PLD within individual dogs over time.
  
  
  METHODS
  Flat-Coated Retrievers that had previously undergone gonioscopy under the UK/ECVO hereditary eye schemes were included in the study.
  
  
  METHODS
  A second gonioscopic examination was performed 1.92-12.58 years later (mean 6, median 5.75 years) and the results compared. 39 FCR (17 males, 22 females) in the UK and 57 FCR (27 males, 30 females) in Switzerland were included. Slit-lamp biomicroscopy, indirect ophthalmoscopy, and gonioscopy were performed in all dogs. Gonioscopy allowed classification as either unaffected or affected; percentage of the iridocorneal drainage angle (ICA) affected by PLD was determined, before calculating progression observed as mild, moderate, or severe.
  
  
  RESULTS
  39 of 96 (40.6%) dogs demonstrated progression of PLD (P < 0.0001). Of these, 13 of 96 (13.5%) were classified as mild progression (from either unaffected to 10-20% or 10-20% to 20-90% ICA affected). Progression was more extensive in 26 of 96 (27.1%) dogs (P < 0.0001), of which 12 of 96 (12.5%) went from unaffected to severe PLD of >90% ICA affected, consistent with a high risk of glaucoma.
  
  
  CONCLUSIONS
  To the authors' knowledge, this is the first report describing progression of PLD in individual dogs over time, in a breed affected by primary, angle closure glaucoma.
authors.affiliation: Davies Veterinary Specialists, Manor Farm Business Park, Higham Gobion, Hertfordshire, UK.
authors.forename: Rose
authors.initials: R
authors.lastname: Pearl
authors.forename: David
authors.initials: D
authors.lastname: Gould
authors.forename: Bernhard
authors.initials: B
authors.lastname: Spiess
mesh_terms: D000818:Animals; D018450:Disease Progression; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005128:Eye Diseases / Q000473:pathology / Q000662:veterinary*; D005260:Female; D005901:Glaucoma / Q000473:pathology / Q000662:veterinary; D006068:Gonioscopy / Q000662:veterinary; D007498:Iris / Q000473:pathology; D008297:Male; D014129:Trabecular Meshwork / Q000473:pathology
keywords: Flat-Coated Retriever; goniodysgenesis; gonioscopy; iridocorneal angle; pectinate ligament dysplasia; primary glaucoma