What Is Pigment Dispersion Syndrome?
Pigment gives your iris its color. Pigment dispersion syndrome (PDS) happens when the pigment rubs off the back of your iris. The pigment then floats around to other parts of the eye. The tiny bits of pigment can clog your eye's drainage angle. This can cause eye pressure problems.
Your eye keeps a healthy pressure by making a fluid called aqueous humor. As new aqueous flows into your eye, the same amount flows out. If enough fluid doesn't leave the eye, pressure inside the eye (intraocular pressure, or IOP) builds up over time and can damage the optic nerve. This is called glaucoma. When PDS has progressed to this stage, it is called pigmentary glaucoma. Not everyone who has pigment dispersion syndrome will develop pigmentary glaucoma.
What Are Symptoms of Pigment Dispersion Syndrome?
Many people with pigment dispersion syndrome (PDS) do not have any symptoms. Some people may have blurring of vision or see halos after exercise.
Even if you have pigmentary glaucoma, you may not notice any symptoms. In time, as the optic nerve becomes more damaged, you may notice that blank spots begin to appear in your field of vision. You usually won’t notice these blank spots in your day-to-day activities until the optic nerve is significantly damaged and these spots become large. If all of the optic nerve fibers die, blindness results.
In this close-up photograph of an eye, small flecks of pigment are seen floating inside the eye, a sign of PDS
Who Is at Risk for Pigment Dispersion Syndrome?
PDS may be inherited (passed from parent to child). It is more common among:
- people with myopia (nearsightedness)
- people in their 20s and 30s. Other types of glaucoma are usually diagnosed after the age of 40.
- white people
Pigment Dispersion Syndrome Diagnosis
Because there are often no symptoms, PDS is usually diagnosed during a regular eye exam. That is why it is so important to have an eye exam with your ophthalmologist.
During a thorough eye exam, your ophthalmologist will:
- check your eye pressure
- do other tests like a gonioscopy, if PDS is suspected. This lets your ophthalmologist look at the eye's drainage angle. He or she can see if something is blocking the fluid from leaving the eye.
- check for glaucoma. They will examine your optic nerve for signs of damage, and check your side (peripheral) vision.
These tests are the same used for a glaucoma diagnosis and will determine if you have pigmentary glaucoma. Your ophthalmologist looks for the tell-tale signs of pigment floating in the eye (including at the back of the cornea) or small sections of pigment missing from your iris.
Pigment Dispersion Syndrome Treatment
PDS treatment varies depending on how it is affecting your eye pressure:
For pigment dispersion syndrome with normal or only slightly elevated IOP, there is a low risk of damage to the optic nerve. No treatment is needed other than seeing your ophthalmologist one time each year. He or she will monitor your condition by checking your IOP and looking for any changes in your vision.
For pigment dispersion syndrome with elevated IOP, there is a greater risk of damage to the optic nerve. To lower IOP, you may be treated with medicated eye drops or laser therapy.
When IOP from PDS is so high that it damages the optic nerve, this is then called "pigmentary glaucoma." In this case, treatment is needed and it may be medicated eye drops, laser therapy, or surgery.