Histologic and immunohistochemical characterization of lens capsular plaques in dogs with cataracts.
OBJECTIVE
To determine histologic and immunohistochemical characteristics of the multifocal adherent plaques that commonly develop on the internal surfaces of the anterior and posterior lens capsules in dogs with cataracts.


METHODS
31 anterior and 4 posterior capsular specimens collected during lens extraction surgery in dogs with cataracts.


METHODS
Specimens were evaluated, using light and transmission electron microscopy. Immunohistochemical techniques were used to localize cytokeratin, vimentin, alpha-smooth muscle-specific actin, fibronectin, tenascin, and transforming growth factor-beta (TGF-beta) within plaques.


RESULTS
Histologically, plaques comprised elongated spindle-shaped cells that formed a placoid mass. Cells were embedded in an extracellular matrix containing collagen fibrils, often with duplicated or split basement membranes. Immunohistochemically, normal lens epithelial cells and cells within plaques stained for vimentin. Most cells and some areas of the extracellular matrix within plaques stained for TGF-beta and alpha-smooth muscle-specific actin. Fibronectin and tenascin were also detected in the extracellular matrix.


CONCLUSIONS
Canine lens capsular plaques are histologically and immunohistochemically similar to posterior capsule opacification and subcapsular cataracts in humans, which suggests that the canine condition, like the human conditions, is associated with fibrous metaplasia of lens epithelial cells. Transforming growth factor-beta may play a role in the genesis of capsular plaques. Because severity of plaques was correlated with stage of cataract development, earlier surgical removal of cataracts may be useful to avoid complications associated with plaque formation.
Colitz
C M
CM
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
Malarkey
D
D
Dykstra
M J
MJ
McGahan
M C
MC
Davidson
M G
MG
D000199:Actins / Q000032:analysis; D000818:Animals; D002386:Cataract / Q000473:pathology / Q000662:veterinary*; D002387:Cataract Extraction / Q000662:veterinary; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005353:Fibronectins / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007908:Lens, Crystalline / Q000473:pathology* / Q000648:ultrastructure; D019063:Tenascin / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000032:analysis
D000199:Actins; D005353:Fibronectins; D019063:Tenascin; D016212:Transforming Growth Factor beta