Pigment Dispersion Syndrome

Pigment dispersion syndrome (PDS) is characterized by the dispersion of iris pigments from the iris pigment epithelium and their deposition at the back of the corneal endothelium and in the anterior segment. PDS was first defined by Friedrich E. Krukenberg in 1899 as a vertical pigmentary line in the endothelium. Initially, PDS was thought to be a congenital anomaly. In 1901 Von Hippel described pigment dispersion in the trabecular meshwork, which is related to glaucoma in PDS. The term pigmentary glaucoma (PG) was proposed by Sugar in 1940. Patients will PDS can have raised intraocular pressure or develop PG. Patients with PDS may be asymptomatic or present with pain, redness, and photophobia. Early diagnosis and meticulous management are critical components in managing patients with PDS and preventing vision loss due to misdiagnosis. The diagnosis is clinical with classical signs such as Kruckenberg spindles, pigments in the anterior chamber, trabecular meshwork,  concave iris configuration, diffuse iris transillumination defects, pigments on the anterior lens surface with Scheie stripe and Zentmayer ring of pigments. The diagnosis is made by basic glaucoma investigations like intraocular pressure measurement, gonioscopy, visual field assessment, anterior and posterior segment OCT. The treatment can be medical management with antiglaucoma drugs, laser therapy, and filtration surgery. Scheie and Cameron, in their analysis of 799 patients, subdivided PDS into those with high IOP and those with normal IOP. They also assessed glaucomatous damage in each patient. The study results favored normal IOP patients, and the male: female ratio was 3 to 2. The most common clinical feature was trabecular meshwork pigmentation in approximately 85% of patients, followed by refractive error and iris transillumination defects. Ultimately, 66% of PDS patients responded well to medical therapy, and nonresponders required filtration surgery.