Morphologic changes of the anterior corneal epithelium caused by third eyelid removal in dogs.

Morphologic changes of corneal epithelium after third eyelid removal were observed in six normal Beagle dogs. The observation was conducted on the 17th, 35th and 72nd week after the removal. Morphologic changes were observed on corneal epithelium layers at 17 and 35 weeks post excision of the third eyelid but they were limited to minor changes including abnormal intercellular adhesion and further exfoliation of superficial cells at 72 weeks. The reduced BUT and evidence of vital positive staining correspond with these morphologic changes. Therefore, these changes are thought to be important findings from a morphologic view point in identifying pathologic symptoms of the cornea using clinical evaluation methods such as BUT and vital staining method. Grossly, no clinical indication of ocular disease was indicated by slit-lamp biomicroscopic observation; however, the BUT shortage and positive finding of vital staining indicated that the corneal epithelium layers after third eyelid removal lacked the essential barrier function. Thus, it would seem appropriate to consider that such a condition of the ocular surface would worsen with excessive exposure of the ocular surface, palpebration disorders and other exogenous factors.