The pigment dispersion syndrome with open-angle glaucoma usually affects individuals under the age of 30 years. In addition to the typical optic nerve degeneration seen in all forms of glaucoma, the pigment dispersion syndrome is characterized by distinctive ... The pigment dispersion syndrome with open-angle glaucoma usually affects individuals under the age of 30 years. In addition to the typical optic nerve degeneration seen in all forms of glaucoma, the pigment dispersion syndrome is characterized by distinctive clinical features. One feature is the deposition of pigment granules from the iris epithelium on various ocular structures, including the trabecular meshwork. This disorder frequently affects young myopic individuals. In the early stages of the disease, affected individuals may have clinical evidence of dispersed pigment without an associated elevation of intraocular pressure and optic-nerve degeneration. However, as the disease progresses, approximately 50% of patients develop increased intraocular pressure and degeneration of the optic nerve, causing permanent loss of sight (Richter et al., 1986). Siddiqui et al. (2003) reviewed the results from 113 patients newly diagnosed with pigment dispersion syndrome over a 24-year period. The risk of developing pigmentary glaucoma from pigment dispersion syndrome was 10% at 5 years and 15% at 15 years. Young myopic men were most likely to have pigmentary glaucoma. An intraocular pressure greater than 21 mm Hg at initial examination was associated with an increased risk of conversion. Pigment dispersion syndrome and pigmentary glaucoma result from iridozonular friction causing disruption of the iris epithelium and deposition of iris pigment on the anterior segment structures. Tesser (2003) reported a 48-year-old patient with congenital bilateral iris colobomas (see 120200). Elevated intraocular pressure was present in the eye with a partial iris coloboma and iris transillumination defects but pigment deposition on the ipsilateral corneal endothelium (Krukenberg spindle). The other eye was diagnosed as having mild ocular hypertension, without pigment dispersion or glaucoma, in association with a complete iris coloboma. Tesser (2003) concluded that pigment dispersion was prevented in the eye with the complete iris coloboma. Grassi et al. (2004) reported an 8-year-old boy with atypical PDS. In addition to iris transillumination defects, iris backbowing, heavy pigmentation of the trabecular meshwork, and elevated intraocular pressure, he had emmetropia, mild posterior subcapsular cataract, small pupils, and peripheral anterior synechiae. Dorairaj et al. (2007) reported 3 unrelated children with PDS: an 11-year-old girl with bilateral PDS with elevated intraocular pressure whose mother had PDS, and two 12-year-old boys, 1 with a more severe phenotype and both parents affected, and the other with a less severe phenotype and 1 parent affected.