title: Examination of the anterior uveoscleral pathway in domestic species.
abstract: OBJECTIVE
  To investigate the uveoscleral (US) pathway in the normal eyes of four domestic spp.: the cat, pig, cow and horse by examining the comparative anatomical structure of anterior US pathway.
  
  
  METHODS
  Four cats, ten pigs, four cows, eight horses.
  
  
  METHODS
  Formalin-preserved specimens from anterior uveas of the cat, pig, cow and horse were embedded and serially sectioned sagittally and tangentially and stained with H&E, Masson's trichrome, smooth muscle actin immunolabel, or elastin stain.
  
  
  RESULTS
  Spaces between the endings of the outer anterior ciliary body musculature (CBM) formed avenues for the beginning of the US pathway and varied in the amount of extracellular matrix (ECM) material being most developed in the pig. In the cow, other anterior muscle bundles attached the CBM to the sclera concomitant with the presence of an anterior elastic sheath. In the horse, these muscle bundles were connected to branching connective tissue trabeculae within the US pathway that were attached radially to the sclera. In the cat, muscle bundles were more abundant and formed a fine meshwork of trabecular associations with the posterior ICA. Supraciliary development was most pronounced in the horse and least in the pig.
  
  
  CONCLUSIONS
  All species possessed clearly developed and unique US pathways. The outermost muscle bundles of the CBM appeared to have close interaction with the US pathway and the degree of these muscle associations differed with species. The species specific anatomical variations within the US pathway could play a pivotal role in the variability of aqueous outflow along this pathway.
authors: Small Animal Clinical Sciences, University of Florida, PO Box 100126, Gainesville, FL 32610-0126, USA.
authors: Kara
authors: K
authors: Sedacca
authors: Don
authors: D
authors: Samuelson
authors: Patricia
authors: P
authors: Lewis
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000033:anatomy & histology* / Q000145:classification; D002415:Cats; D002417:Cattle; D006736:Horses; D012590:Sclera / Q000294:innervation*; D013045:Species Specificity; D013552:Swine; D014602:Uvea / Q000294:innervation*