Accessibility View Close toolbar

Pigment Dispersion Syndrome

As noted in the section on glaucoma, the vast majority of people with the disease have the open angle type, and most of these have what is known as primary open angle glaucoma, or POAG. The main feature of POAG, aside from elevated intraocular pressure (IOP) and visible damage to the optic nerve, is an otherwise normal eye. In other words, there are no other identifiable abnormalities to explain either the pressure or optic nerve damage. The cause or causes of POAG are largely unknown, though numerous genetic defects are being studied for their role in the disease.

A significant number of patients with open angle glaucoma have special forms of the disease, known as secondary open angle glaucomas. In these conditions, there are identifiable abnormalities responsible for the elevated intraocular pressure and associated damage. One such condition, pigment dispersion syndrome, is described below.

Pigment Dispersion Syndrome and Pigmentary Glaucoma

Pigment Dispersion Syndrome (PDS)/pigmentary glaucoma is another relatively common form of secondary open angle glaucoma. This condition typically occurs in younger patients, between the ages of 20 and 45. Patients are more often male and tend to be nearsighted.

In PDS, small pigmented (brown colored) granules are rubbed off the back of the iris due to abnormal contact between the iris and the zonules, the fibers which hold the lens in place. This is believed to be caused by an abnormality of iris anatomy in which the iris is positioned too far back in the eye. Why this develops is not known. The released pigment then floats about the eye, being deposited in multiple locations, including within the trabecular meshwork and drainage canals where it causes damage and may lead to elevated IOP.

Diagnosis of PDS is made by identifying typical patterns of pigment deposition within the eye. Pigment is frequently seen on the cornea in a spindle-shaped pattern known as a Krukenberg’s spindle, and may be seen on the front or back surface of the lens.

Often quite dense and dark, pigment is always found within the trabecular meshwork. Slit-like defects in the iris, known as transillumination defects, are nearly always seen to some degree, and represent areas where pigment has been extensively worn away by rubbing against zonules. These can be seen in the adjacent photo. The front of the eye, called the anterior chamber, is often abnormally deep in appearance due to the backwards displacement of the iris.

IOP in pigmentary glaucoma can fluctuate widely, often becoming quite high. In fact, IOP “spikes” have been noted to occur spontaneously or, in some cases, after exercise due to sudden release of large amounts of pigment. While most types of glaucoma seldom have any acute symptoms, these rapid elevations of pressure can lead to pain and blurred vision, at times with halos seen around lights. Anyone diagnosed with PDS should report such episodes to their eye doctor, as adjustments in treatment might be indicated.

Not everyone with PDS develops elevated IOP or glaucoma. In fact, there appears to be no direct correlation between the amount of pigment in the trabecular meshwork and the level of intraocular pressure. The reasons for this are not understood, but it is believed that pigmentary glaucoma requires more than just pigement release, that there must be some other abnormality of the drainage canals which has not yet been identified. If PDS is identified during an examination and the optic nerves and IOP are normal, a few additional pressure checks may be performed over the next several months. If IOP remains normal over multiple visits, observation every 6 to 12 months may be indicated.

Treatment of pigmentary glaucoma is similar to that of other types of open angle glaucoma. Medications are usually the first option, often with multiple medications required to control pressure fluctuations. Laser trabeculoplasty can have a very good effect in PDS, often dropping the IOP significantly. The drop in pressure from trabeculoplasty is temporary however, and IOP may begin to elevate again within a few years. Furthermore, patients with PDS occasionally experience substantial elevation in IOP after laser treatment, and at times this may be sustained. Therefore, caution must be taken when performing this procedure. Finally, glaucoma filtering surgery such as trabeculectomy can be performed quite successfully, and is likely to be necessary in at least one eye if IOP cannot be otherwise controlled.

Exclusive Offer

New Patients receive 15% OFF Second Pair of Complete Glasses!

Hours of Operation

Our Regular Schedule

Offices Hours


8:00 am-5:00 pm


8:00 am-5:00 pm


8:00 am-5:00 pm


8:00 am-5:00 pm


8:00 am-5:00 pm






Find us on the map

Main Office and Surgery Center

5599 North Oracle Rd.
Tucson, AZ 85704

Phone: 520-293-6740

Rooney Ranch Office

10425 N. Oracle Rd., Suite 135
Tucson, AZ 85737

Phone: 520-293-6740

Arizona Eye Laser Center

6837 N. Oracle Rd, Suite 15
Tucson, AZ 85704

Phone: 520-293-6740


Reviews From Our Satisfied Patients

  • "FABULOUS! They are all kind, professional and know what they are doing!!"
    Nanci M.
  • "Dr. Bakewell explains everything .pros and cons . I would recommend him 💯 %"
    Connie P.
  • "What a great job! I was 20/800 did prk now am 20/15 in just one month.well worth it.thank you very much to all there staff"
    Antonio C.
  • "Excellent surgeons that are caring people too! Great job."
    Rob M.

Featured Articles

Helpful and Informative Resources

  • How to Clean Your Eyeglasses

    Do you know how to clean your eyeglasses correctly? Take a look a few tips that will keep your specs cleaner. ...

    Read More
  • All About Amblyopia

    Amblyopia, also known as lazy eye, is a visual disorder caused by abnormal vision development, often occurring during infancy. Patients with amblyopia have reduced vision in one eye, because it is not working properly in conjunction with the brain. With early detection and proper treatment, loss of ...

    Read More
  • All About Glaucoma

    Glaucoma is a serious disorder that can damage the optic nerves of your eyes if left untreated. The optic nerve carries images from your eyes to your brain. If the nerve is damaged, full or partial vision loss can occur. In some cases, people develop glaucoma because the pressure in their eyes begins ...

    Read More
  • Binocular Vision: Disorders and Treatment

    For many, the term binocular vision conjures images of super powers or the rare ability to spot objects far away, but having binocular vision simply means having two eyes with which to see. Binocular vision does lend creatures with two eyes advantages over those with only one, such as enhanced vision, ...

    Read More
  • Curbing Macular Degeneration

    Macular degeneration represents one of the most significant causes of vision loss in older adults. According to the Centers for Disease Control and Prevention, an estimated 1.8 million people currently suffer from macular degeneration, with an additional 7.3 million people at risk of developing this ...

    Read More
  • Diabetic Retinopathy: What Is It?

    Diabetic retinopathy refers to several eye problems that are characterized by damage to the light-sensitive retina, caused by excessive blood sugar levels. Almost half of Americans with diabetes suffer from some level of diabetic retinopathy. When glucose levels in the blood are not properly controlled, ...

    Read More
  • Glaucoma Care: What You Need to Know

    Glaucoma is the second leading cause of blindness worldwide, reports the Glaucoma Research Foundation. This common eye condition typically affects older adults, although infants and young adults are also at risk. Fortunately, however, cutting-edge research is improving diagnosis and treatment of this ...

    Read More
  • Strabismus

    Strabismus is the medical term for the misalignment of the eyes. Commonly referred to as cross-eyed or wall-eyed, strabismus may involve either one or both eyes turning inward, outward or even up or down. It is one of the most common vision conditions in young children, affecting somewhere between 2 ...

    Read More
  • What Is Astigmatism?

    Astigmatism is an extremely common eye condition that affects both children and adults. It occurs when there is an imperfection in some part of your cornea, the clear tissue that covers your iris. Light rays pass through the cornea as they travel to the retina, a thin layer of cells at the back of your ...

    Read More
  • What You Need to Know About Dry Eye

    If you have never suffered from dry eye, you might not appreciate how important your tears are to your eye health. Without enough moisture, your eyes can become dry, itchy, red and uncomfortable. Dry eye occurs when you do not make enough tears or the tears you produce are not high quality. The Importance ...

    Read More

Newsletter Signup

Sign Up to Receive More Articles