PTERYGIUM. 



This name is employed to designate a triangular conjunctival 

 fold broader at its sclerotic end and gradually narrowing to its 

 corneal extremity) with loose, slightly overlapping borders, and 

 firmly fixed to the structures beneath. It is more vascular than 

 the surrounding conjunctiva, and its comparatively large blood- 

 vessels have suggested the veins of an insect's wing — hence its 

 name. The growth may extend from either canthus toward or 

 partly over, the cornea. 



MoUer and Ivcclainche claim its existence in dogs, though 

 rarely to such an extent as to demand surgical interference. 

 Dunewald operated on a case in the cow. 



Unless growing, it need not be interfered with. It may be dis- 

 sected up with scissors, the narrow end being dragged on by for- 

 ceps. Another method is to cauterize the narrow end with the elec- 

 tric cautery which leads to material contraction of the entire mass. 



XEROSIS CORNER (EPITHEI.IAI.IS). DRY KERATITIS. 



This is described by Mayer as following distemper in dogs. It 

 seems to begin in the epithelial layer of the conjunctiva, which 

 becomes dry, lustreless, spotted, opaque and fatty so that water 

 runs over it without wetting it. It may extend deeply into the 

 substance of the cornea and lead to the development of a scar. 

 When scraped and examined under the microscope the scrapings 

 are found to consist of epithelium undergoing fatty degeneration 

 and myriads of xerosis bacilli. As the disease takes occasion to 

 attack by reason of the debility of the system, the treatment is 

 mainly corroborative and tonic, including the arrest of the affec- 

 tion on which the weakness depends. The early application of 

 antiseptics is desirable (iodoform i, vaseline lo ; mercuric 

 chloride i, vaseline 3000). Warm compresses and a bandage 

 may be tried. 

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