Such findings would strongly suggest that anterior chamber immune abnormalities play a role in the etiology of pigmentary glaucoma in humans. It already has been suggested that decreased amounts and expression of PEDF are found in patients with glaucoma and other neurodegenerative diseases of the eye. However, the source of the decreased expression has not been identified. If IL-18 production is elevated in pigmentary glaucoma and is up regulated in the anterior chamber structures of the eye in human patients with the disease, this also would be highly suggestive that localized anterior chamber immune dysfunction plays a role in the development of this disease.