Electron microscopic immunohistochemistry of ocular and extraocular pseudoexfoliative material

To investigate the nature of extraocular pseudoexfoliative (PSX) material, and to validate the hypothesis that the PSX syndrome is a systemic disorder, we studied the immunoreactivity of intraocular and extraocular PSX material from patients with the PSX syndrome using antibodies against proteins of extracellular matrices. Surgical specimens of four different tissues were obtained from human eyes with the PSX syndrome: nine trabecular tissues, three cataractous lenses, six bulbar conjunctivas, and seven lid skins. These tissues were processed for electron microscopic immunohistochemistry, and stained with antibodies against vitronectin, fibronectin, laminin, and elastin, by an indirect immunogold procedure. Density of the gold particles located on the PSX material was estimated by video image analysis. Statistical analysis of the data revealed that the PSX material from trabecular tissues, lenses, bulbar conjunctivas, and lid skins had almost identical immunoreactivity to the antibodies studied. PSX materials of trabecular tissues, lenses, bulbar conjunctivas, and lid skins were found to have not only a similar ultrastructure, but also almost identical immunohistochemical characteristics. These results support the hypothesis that the PSX syndrome is a systemic disorder.