What is Pigment Dispersion Syndrome?
Pigment dispersion syndrome (PDS) is a rare eye condition that develops when pigment fragments that are typically attached to the eye's iris (colored part of the eye) flake off and enter the aqueous humor (clear fluid).
Pigment flaking occurs from the iris and lens fibers rubbing together during everyday activities such as vigorous exercise. Many people with PDS also have myopia (nearsightedness).
Symptoms of PDS include blurry vision and halos around light.
Floating pigment granules can disturb fluid flow by clogging the drainage system and trabecular meshwork (where eye fluid drains out). This results in elevated intraocular pressure (IOP).
Increased IOP can lead to glaucoma, which is permanent damage to the optic nerve (communication pathway from the eye to the brain). If not treated, glaucoma can lead to severe vision changes and blindness.
Pigment Dispersion Syndrome and Pigmentary Glaucoma
Pigment dispersion syndrome leads to pigmentary glaucoma when the pigment granules accumulate in the eye's drainage system. This process disturbs the fluid flow rate and increases eye pressure.
Pigmentary glaucoma is classified as secondary open-angle glaucoma, which means the drainage angle is open. Still, a clog does not allow eye fluid to drain consistently. A slight fluctuation in drainage rate leads to eye pressure spikes, permanently damaging the optic nerve.
Pigment dispersion syndrome leads to glaucoma 30% of the time. While both men and women develop PDS at the same rate, men develop pigmentary glaucoma at three times the rate as women.4
Pigmentary glaucoma affects younger people more than primary open-angle glaucoma, the most common type of glaucoma.
Who is at Risk of Developing Pigmentary Glaucoma?
While primary glaucoma typically affects people over 60, pigmentary glaucoma is prevalent in younger, middle-aged adults.
Common risk factors for PDS and pigmentary glaucoma include:
- Nearsightedness (myopia)
- Family history of PDS
- People with flat corneas (transparent outer layer of the eye)
Pigmentary Glaucoma and Vigorous Exercise
Vigorous exercise, such as jogging and basketball, is associated with both PDS and pigmentary glaucoma.
Some exercises' strenuous movements and jarring motions can cause pigment granules to flake off the iris into the eye fluid.
Some aerobic exercises such as biking, swimming, and walking promote lower intraocular pressure by improving blood flow to the brain and eyes.
If you have PDS, consult an eye doctor before exercising. Medication to lower eye pressure can help prevent pressure spikes before exercising.
Symptoms of Pigmentary Glaucoma
Because intraocular pressure tends to gradually increase over time, early stages of pigmentary glaucoma typically don't have any symptoms. This is why glaucoma has also been called the “silent thief of sight.”
The first warning signs of pigmentary glaucoma are typically blind spots in your peripheral vision (side vision).
As the disease progresses, there are noticeable changes to central vision and visual acuity (distance vision). Redness and halos around lights are also warning signs of pigment dispersion syndrome and glaucoma.
While glaucoma treatment can slow disease progression, optic nerve and vision loss damage is permanent.
Diagnosing & Treating Pigmentary Glaucoma
Pigmentary glaucoma doesn't have symptoms in the early stages. This is why it is crucial to get an annual eye exam to screen for glaucoma and other eye conditions.
An ophthalmologist diagnoses pigmentary glaucoma during an eye exam. They will look for evidence of pigment fragments in the drainage angle and check intraocular pressure.
Optic nerve damage will be assessed by looking at the back of the eye. Vision field tests look for blind spots in the peripheral vision (side vision) and visual acuity tests screen for central and distance vision changes.
Lowering eye pressure is the first line of treatment for people diagnosed with pigmentary glaucoma.
Medicated eye drops are the gold standard in reducing intraocular pressure, such as:
Antiglaucoma miotics, including pilocarpine, contract the pupils. These eye drops help:
- Reduce friction between the iris and lens
- Reduce eye pressure
- Promote the flow of aqueous humor (eye fluid).
If medication alone is ineffective at reducing and maintaining a normal eye pressure, laser treatment and traditional filtration surgery may be necessary. Options include:
- Selective laser trabeculoplasty opens up the drainage angle to promote the outflow of fluid
- Laser iridotomy creates a small hole in the iris to move fluid out of the eye
- Trabeculectomy creates a bleb (reservoir) to capture fluid and decrease IOP
- Tube shunt surgery implants a hollow tube called a shut to divert fluid into a reservoir and away from the eye
Pigmentary glaucoma stems from pigment dispersion syndrome, which is when pigment granules flake off the iris and into the eye's aqueous humor (clear fluid).
Pigment accumulation in the drainage system clogs the trabecular meshwork (where eye fluid drains out). This leads to an elevated intraocular pressure that can damage the optic nerve and cause pigmentary glaucoma.
People with pigment dispersion syndrome develop glaucoma 30% of the time. Glaucoma causes permanent damage to the optic nerve, resulting in vision loss and blindness if not treated. Because the eye's pressure increases over time, there aren't any symptoms in the early stages of the disease.
Symptoms of advanced-stage glaucoma include:
- Blind spots in the peripheral vision (side vision)
- Blurry vision
- Changes in central and distance vision
Early warning signs of pigment dispersion syndrome include blurry vision and halos around light.
Pigmentary glaucoma is diagnosed during a comprehensive eye exam that includes glaucoma screening, looking for pigment fragments in the drainage angle, and assessing optic nerve damage.
Glaucoma treatment starts with medicated eye drops to reduce eye pressure. If those are not effective alone, laser treatment or traditional filtration glaucoma surgery may be necessary.
It is essential to get a comprehensive eye exam once a year to catch pigmentary glaucoma early. This is because most people are asymptomatic in the beginning stages. Optic nerve damage is also permanent.
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