ABSTRACT
Pigmentary glaucoma is a secondary open-angle glaucoma associated with the pigment dispersion syndrome (PDS). Although most cases of pigment dispersion syndrome are sporadic, an autosomal dominant pattern has been described and a locus identified in chromosome 7. The disorder is characterized by chafing of the peripheral iris against the anterior lens zonules, to cause the release of pigment from the posterior pigment epithelium. Current thinking on the pathophysiology involves the presence of a reverse pupillary block. With susceptible individuals, each blink compresses the cornea, sending a wave of fluid across the anterior chamber and knocking the lens posteriorly against the elastic tether of the zonules. The anterior chamber volume is increased, causing a momentary relatively lower pressure in this chamber compared with the posterior chamber. Aqueous is drawn into the anterior chamber until the lens is pulled back against the pupil, trapping an abnormally increased volume of aqueous in the anterior chamber. The peripheral iris is pushed back against the zonules, resulting in zonular-iris chafe and pigment dispersion.
