The corneal endothelium is a monolayer of polygonal cells (mostly hexagonal in shape) located on the inner surface of the cornea, in contact with the aqueous humor. This layer governs fluid and solute transport from the anterior chamber to the other layers of the cornea, preserving the slightly dehydrated state that is required for corneal transparency. The corneal endothelium does not regenerate in most species and therefore, if endothelial cell density drops below 500-800 cells/mm2 due to any disturbance, corneal edema will appear and concomitantly, corneal thickness will increase. The corneal endothelium cells can be visualized in vivo by means of biomicroscopy, specular microscopy and confocal microscopy and its normal appearance has been described in different animal species and in humans. Moreover, several physiological factors such as aging or race, among others, can lead to changes in cell density, size and shape of endothelial cells. The knowledge of the normal appearance of the corneal endothelium in each animal species, and how it is affected by different physiological factors, is the basis for detecting and understanding the pathologies that may alter this layer. On the other hand, many primary and secondary alterations of the corneal endothelium, such as Fuchs’ Dystrophy, can lead to blindness in humans and dogs although its initial cause is not known. For this reason, it is essential to search for animal models that allow the study of these pathologies. The purposes of this thesis are numerous. In sheep, the aim is to describe the normal appearance of the corneal endothelium as well as determine if the quadrant of the cornea, the breed or the age of the animal influence on corneal endothelial parameters and/or corneal thickness. In goats, the objective is to study the caprine endothelium and corneal thickness, and to report the variations observed in the endothelium due to aging or different corneal regions. In the tawny owl, a bird of prey, the purpose of the study is to describe its corneal endothelium and determine if aging has any effect on endothelial parameters. Finally, in the dog, the aim is to evaluate if skull index has any impact on corneal endothelium and/or corneal thickness.
Estudio del endotelio corneal en diferentes especies animales
Natalia Coyo Asensio (Author). 13 Jul 2018
Student thesis: Doctoral thesis
Student thesis: Doctoral thesis