ARE THERE SPECIAL ISSUES OF WHICH I SHOULD BE AWARE REGARDING PIGMENT DISPERSION SYNDROME OR PIGMENTARY GLAUCOMA?

Pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) are 2 successive stages of the same disease process characterized by disruption of the iris pigment epithelium (IPE) and deposition of the dispersed pigment granules throughout the anterior segment. The underlying anatomic cause of PDS is the presence of an iris concavity that allows apposition of its posterior surface to the zonular apparatus during pupillary movement or, to a greater degree, accommodation. The underlying etiology of the iris concavity remains unclear. Campbell and others ^1-2 hypothesized that a reverse pupillary-block mechanism exists in which the iris drapes over the lens and acts as a “flap valve,” preventing aqueous in the anterior chamber from returning to the posterior chamber. The pressure in the anterior chamber then exceeds that of the posterior chamber, pushing the iris posteriorly and creating a concave configuration, and forces the IPE into contact with the zonular bundles. Friction during pupillary movement disrupts the IPE, releasing pigment granules into the aqueous humor. The greater the contact, the greater the pigment dispersion should be.