Pigmentary Glaucoma and Pigmentary Dispersion Syndrome

Pigmentary glaucoma development is associated with pigment dispersion syndrome. A chief characteristic of this kind of glaucoma includes the flaking off of pigment from the iris and resulting blockage of the eye’s drainage angle.

The condition is more prevalent in men than women and is usually diagnosed in the third or fourth decade of life.

Treatment options include medication, laser surgery and conventional surgery.

Introduction

Pigmentary glaucoma is a type of secondary open-angle glaucoma that occurs after pigment granules break from your iris and wash into the clear fluid that your eye produces and then into the drainage canals. Granules slowly clog the channel, creating raised eye pressure. 

Pigmentary glaucoma has an earlier age of onset than primary open-angle glaucoma. Whereas doctors diagnose most glaucoma cases after someone is in their 60s or order, this form of the disease presents symptoms when people are in their 30s and 40s. 

That makes this type a top cause of nontraumatic blindness among young adults. In the Western world, it accounts for 1 to 1.5 percent of all glaucoma cases.

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What Is Pigmentary Glaucoma?

When eye pressure from pigment dispersion syndrome — a common eye disorder in young adults — is so high that it causes damage to the optic nerve, doctors refer to the condition pigmentary glaucoma. This form of glaucoma is characterized by increased pigmentation in the back of the cornea and trabecular meshwork, where the eye fluid drains out.

Pigment deposition on the trabecular meshwork blocks the fluid’s natural drainage to outside the eye, leading to increased eye pressure. Initially, it is not harmful to the eye. Visual symptoms are usually only noticeable later when pigmentary glaucoma patients suffer visual field loss.

Causes

Pigmentary glaucoma occurs when pigment dispersion syndrome leads to optic nerve damage. Pigment dispersion syndrome is a disorder that happens when the pigment granules that usually adhere to the back of your iris flake off into the aqueous humor, the clear fluid that your eye produces. The granules sometimes flow toward the eye’s drainage canal, clogging them slowly and raising the pressure within your eye (intraocular pressure).

When the increase in eye pressure damages the optic nerve, pigment-dispersion syndrome converts to pigmentary glaucoma. Studies have reported conversion rates as high as 35-50% in US populations. Men develop this type of glaucoma as much as three times more frequently than women. It also tends to occur more in patients with myopia.

Signs

In its early stages, pigmentary glaucoma usually has no obvious signs. As the optic nerve suffers more damage over time, you may notice blank spots in your field of vision or difficulty with peripheral or side vision. You may experience episodes of pain, halos or blurred vision after dark exposure or exercise.

While the symptoms associated with pigmentary glaucoma are few, during eye exams doctors keep an eye out for several presenting signs of the disease, such as:

• A pigment known as Krukenberg Spindle on the back of the cornea
• Backbowing of your iris
• Small sections of missing pigment from your iris
• Pigment on your lens capsule

Diagnosis

Eye doctors typically diagnose pigmentary glaucoma after a slit lamp examination and measurement of the intraocular pressure (IOP).

A doctor could perform a gonioscopy if there is a reason to suspect pigment dispersion syndrome or pigmentary glaucoma. Through gonioscopy, the doctor will assess the degree of trabecular pigmentation.

Doctors can also confirm the condition by carrying out other conventional glaucoma tests such as:

• Automated perimetry
• Pachymetry
• Anterior segment optical coherence tomography (AS-OCT)
• Ultrasound biomicroscopy (UBM)

Your doctor can use AS-OCT or UBM to examine iris concavity and the degree of iridolenticular contact.

Treatment

Treatment options for pigmentary glaucoma are similar to those for open-angle glaucoma. They include medication and surgery.

Medication

Doctors commonly treat the condition with eye drops, such as:

• Timoptic
• Betagan
• Xalatan
• Optipranlol

They can also use a class of drugs known as miotics. These medications make the pupil become smaller and hinder your iris from rubbing between the supporting fibers of your lens. That helps prevent further pigment release.

Surgical Options

Surgical options range from laser procedures to incisional surgery.

Because of the increased pigment that pigmentary glaucoma patients have in the eyes’ drainage angle, laser trabeculoplasty can be an effective treatment in some people as it helps open the drainage system and lower eye pressure. Doctors can consider trabeculectomy or some other incisional surgery in case a patient exhibits disease progression after treatment with medicines or trabeculoplasty.

The Exercise Connection

Studies have found vigorous exercises like basketball and jogging can lead to increased pigment release, which can block eye drainage further and raise eye pressure significantly. Some patients have reported experiencing halos and blurry vision after strenuous exercise.

It is advisable for people with pigmentary glaucoma or pigment dispersion syndrome to speak to their ophthalmologist before beginning or stopping exercise programs.

Prevention

Early diagnosis and treatment usually allow people with pigmentary glaucoma to maintain excellent vision. As a result, eyecare professionals recommend periodic eye examinations with your ophthalmologist. Doctors usually diagnose pigment dispersion syndrome during regular eye exams.

Having regular examinations is especially important if you have signs of abnormal pigmentation or pigment dispersion syndrome. Avoiding jarring and vigorous exercises may also be helpful.

Some experts consider laser iridotomy as a prophylactic treatment for pigmentary glaucoma. Young people with iris concavity and active pigment release may benefit from the procedure as it equalizes the pressures in the eye’s anterior and posterior chambers as well as pulling the iris from the lens zonules.

FAQs

Can you go blind from pigmentary glaucoma?

Untreated pigmentary glaucoma can cause loss of vision and eventually blindness.

How is it treated?

Pigmentary glaucoma treatment primarily aims at lowering eye pressure because of the difficulty in eliminating or reducing iris pigment release. Eye doctors use treatment options like eye drops and other medications, laser surgery, or filtering surgery. If the condition causes blindness, doctors cannot restore the lost vision.

References

1. Molecular Genetics of Pigment Dispersion Syndrome and Pigmentary Glaucoma: New Insights into Mechanisms (March 2018). Journal of Ophthalmology.

2. Effects of Jogging Exercise on Patients with the Pigmentary Dispersion Syndrome and Pigmentary Glaucoma (July 1992). American Academy of Ophthalmology.

3. Pigment dispersion syndrome / glaucoma (February 2008). University of Iowa Health Care. 

4. Glaucoma (December 2019).Kanski’s Clinical Ophthalmology, Ninth Edition.

5. Pigmentary Glaucoma and Pigment Dispersion Syndrome (November 2021). American Academy of Ophthalmology.

6. Pigment Dispersion Syndrome and Glaucoma (October 2021). Optometrists Network.

7. Pigment Dispersion Syndrome and Pigmentary Glaucoma (October 2019). Glaucoma Research Foundation.

8. Pigmentary Glaucoma: FAQs (October 2021). Optometrists Network.

9. Pigment-dispersion syndrome (May 2015). The Genetic and Rare Diseases Information Center.

10. What are pigment dispersion syndrome and pigmentary glaucoma? (October 2017). Glaucoma Research Foundation.

11. Pigmentary Glaucoma: Answers to Your Questions (April 2018).Glaucoma Research Foundation.

12. Glaucoma, Pigment Dispersion Syndrome. The University of Arizona Health Sciences.

13. What Is Pigment Dispersion Syndrome? (March 2021). American Academy of Ophthalmology.

     

14. Pigmentary Glaucoma: 24-year-old male with episodic haloes around lights and blurry vision (February 2014). University of Iowa Health Care.

15. What is the risk of developing pigmentary glaucoma from pigment dispersion syndrome? (June
    2003). American Journal of Ophthalmology.