Pigment Dispersion Syndrome

Pigment dispersion syndrome (PDS) is a disorder of the eye in which the pigment granules responsible for eye color slough off of the back of the iris and collect in the eye's fluid called the aqueous humor. On its own, PDS does not pose any threat to health or vision, but, according to the Glaucoma Research Foundation, in approximately one-third of PDS cases, these flaky granules may collect in the drainage canals of the eye causing a blockage that, in turn, leads to an increased amount of internal eye pressure. This rise in intraocular pressure can result in pigmentary glaucoma (PG), and damage to the optic nerve.

Statistics

• PDS is quite rare and occurs most frequently in white, near-sighted males between the ages of 30 and 50, according to the Handbook of Ocular Disease Management. Its cause is unknown, though appears to occur due to an anatomical anomaly in which the eye's iris and the fibers of the lens rub against one another. This change in anatomy may be genetically caused, though a link has yet to be determined.

Symptoms and Diagnosis

• PDS does not usually produce any symptoms and is typically discovered during routine eye examinations. To diagnose PDS, an optometrist or ophthalmologist will observe granular brown bands resembling melted chocolate in different parts of the eye when a light is shone on it. If the PDS has progressed to PG, symptoms may include blurred vision, eye pain and seeing colored halos around lights. However; according to the Handbook of Ocular Disease Management, PG also may be asymptomatic.

Treatment

• As PDS does not cause any ill effects, no treatment is prescribed. Patients are instead treated as those at high risk of developing glaucoma and should have professional eye exams three to four times per year to determine if the PDS has progressed to PG. If pigmentary glaucoma is detected, the primary treatment is use of eye drops from a class of drugs known as mitotics, according to the Glaucoma Research Foundation. If these are ineffective, other drugs such as beta blockers may be necessary to relieve intraocular pressure. Laser surgical procedures also may be prescribed .

Considerations

• Mitotic drugs are limited in their usefulness, due to the fact that they can cause blurred vision. A surgical procedure known as laser iridotomy; in which small holes are created in the iris to relieve pressure, appears to be effective in only a portion of patients, according to the Glaucoma Research Foundation. This is also true of another surgical alternative, laser trabeculoplasty, which helps to open up the drainage systems of the eyes. As PG progresses quite rapidly and can result in vision loss, a combination of treatment options may be necessary.

Warnings

• There appears to be a connection between certain exercises, such as jogging and basketball, and an increased risk of PDS progressing to PG. The association is likely physical jarring, causing more pigment granules to be rubbed off of the iris, according to the Glaucoma Research Foundation. Patients who have been diagnosed with PDS or PG should discuss their exercise regimens with their eye care specialists.