title: Morphology and immunohistochemistry of spontaneous chronic corneal epithelial defects (SCCED) in dogs.
abstract: OBJECTIVE
  To determine the morphologic features of the epithelium and extracellular matrix in spontaneous chronic corneal epithelial defects (SCCED) in dogs.
  
  
  METHODS
  Forty-eight superficial keratectomy specimens were obtained after confirmation of the presence of a superficial corneal erosion for longer than 3 weeks with no discernible underlying cause. Histologic samples were examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. Immunolocalization of laminin, collagen IV, fibronectin, and collagen VII was performed.
  
  
  RESULTS
  Epithelial cells adjacent to the defect were poorly attached to the underlying extracellular matrix. A prominent superficial stromal hyaline acellular zone composed of collagen fibrils in the area of the erosion was present in most specimens. Samples exhibited a varying degree of fibroplasia, vascularization, and leukocytic infiltrate. Laminin, collagen IV, and collagen VII were usually either not present or were present only in discontinuous segments on the surface of the erosion. Fibronectin usually coated the surface of the erosion, either as a continuous sheet or in discontinuous segments. Transmission electron microscopy of 15 samples revealed that the basement membrane was either absent in the area of the erosion or was present only in discontinuous segments. Scanning electron microscopy of eight of nine samples confirmed the absence of continuous basement membrane. Epithelial and extracellular matrix components in the peripheral cornea appeared normal.
  
  
  CONCLUSIONS
  Most canine patients with spontaneous chronic corneal epithelial defects do not have a normal basement membrane structure in the region of the epithelial defect and have other abnormalities in the subjacent extracellular matrix that may reflect a part of the underlying pathophysiology of chronic and recurrent erosions.
authors.affiliation: Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 53706, USA.
authors.forename: E
authors.initials: E
authors.lastname: Bentley
authors.forename: G A
authors.initials: GA
authors.lastname: Abrams
authors.forename: D
authors.initials: D
authors.lastname: Covitz
authors.forename: C S
authors.initials: CS
authors.lastname: Cook
authors.forename: C A
authors.initials: CA
authors.lastname: Fischer
authors.forename: D
authors.initials: D
authors.lastname: Hacker
authors.forename: C M
authors.initials: CM
authors.lastname: Stuhr
authors.forename: T W
authors.initials: TW
authors.lastname: Reid
authors.forename: C J
authors.initials: CJ
authors.lastname: Murphy
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000378:metabolism / Q000648:ultrastructure; D002908:Chronic Disease; D003094:Collagen / Q000378:metabolism; D003316:Corneal Diseases / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000378:metabolism / Q000473:pathology*; D004285:Dogs; D019573:Epithelium, Corneal / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007797:Laminin / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning
chemical_list: D005353:Fibronectins; D007797:Laminin; D003094:Collagen