Abstract
Purpose: :
To characterize the aqueous outflow pathway of the pig eye and to determine whether the expression of ELAM–1 in the trabecular meshwork system of the porcine eye subjected to induced glaucoma is elevated, as naturally occurs in human glaucoma.
Methods: :
Fluorescent dextrans and microspheres were applied to the anterior chamber of the porcine eye in order to identify the outflow pathway. Twenty to sixty minutes after application of the dextrans and a few days to months after application of the microspheres, pig eyes were fixed with 4% paraformaldehyde, cryoprotected, OCT embedded and sectioned. The localization of the fluorescent dextrans and microspheres was identified by fluorescent microscopy. Moreover ELAM–1 was immunohistochemically detected in the trabecular meshwork system of 5 pigs, in which cauterization of the episcleral veins was performed to the left eyes to induce glaucoma, while the right eyes were maintained intact as controls.
Results: :
The aqueous outflow pathway of the porcine eye is principally made up of a series of endothelial–cell–lined multiple channels in the angle of the anterior chamber comprising the trabecular meshwork and Schlemm’s canals, which are connected to the episcleral venous system. Immunodetecion of ELAM–1 in a human trabecular sample obtained from trabeculectomy was performed as a positive control. ELAM–1 expression was found to be moderately elevated in the trabecular meshwork of the glaucomatous porcine eye and not present in that of the control eye.
Conclusions: :
We have characterized the trabecular meshwork and multiple Schlemm's canals in the porcine eye. Our results indicate that overexpression of ELAM–1 in porcine eyes with induced glaucoma is related to increased IOP, as well as retinal ganglion cell loss, and optic nerve damage.
Keywords: outflow: trabecular meshwork • intraocular pressure • anterior chamber