Expression of endothelial leukocyte adhesion molecule 1 in the aqueous outflow pathway of porcine eyes with induced glaucoma

PURPOSE: To determine if the expression of endothelial leukocyte adhesion molecule 1 (ELAM-1) in the trabecular meshwork system of the porcine eye, when subjected to experimental glaucoma, is increased as it does in human glaucoma. METHODS: Immunohistochemistry using a specific mouse antihuman ELAM-1 antibody was performed on the trabecular meshwork system of five pigs. The episcleral veins of the left eyes were cauterized as reported elsewhere to induce glaucoma. Immunodetection of ELAM-1 was assayed in human trabecular meshwork samples obtained from trabeculectomy as a positive control. RESULTS: Pig eyes exhibiting elevated intraocular pressure (IOP) and damage to retinal ganglion cells (RGCs) due to experimental glaucoma as reported elsewhere, were found to exhibit ELAM-1 immunoreactivity in their trabecular meshwork. CONCLUSIONS: ELAM-1 protein, the first molecular marker for human glaucoma, can also be considered a candidate molecular marker of induced glaucoma in the pig model of experimental glaucoma. The results of our study further validated the pig eye as an animal model of glaucoma, since increased expression of ELAM-1, which has been found in the trabecular meshwork of human eyes with glaucoma, is also found in pig eyes subjected to experimental glaucoma via episcleral vein cauterization.