Pigmentary glaucoma (PG) is a type of secondary open-angle glaucoma, meaning there is an identifiable cause that has led to optic nerve damage and vision loss. The identifiable cause in this instance is called pigment dispersion syndrome (PDS).* 

How does it occur?  

The pigments in your eye give color to your iris. In some people, the pigments rub off the back of the iris when the fibers supporting the lens rub against it, which is a condition known as pigment dispersion syndrome. 

As the pigment granules flake into the clear liquid of the eye and attempt to drain out of the tear ducts, the granules clog up and cause increased intraocular pressure (IOP). Elevated IOP leads to optic nerve damage, vision loss, and eventually pigmentary glaucoma. 

Nearly 50% of people with pigment dispersion syndrome develop pigmentary glaucoma.  

What are the risk factors for PDS and PG? 

• Sex: PDS cases are similar in both genders, but PG cases are approximately three times more common in males. 
• Age: Males typically develop PDS and/or PG in their 30s, while females tend to develop them in their 40s. 
• Myopia (nearsightedness): This is the most common refractive error seen in both PG and PDS. 
• Anatomy of the eye: A concave iris, posterior iris insertion, and flat corneas are more commonly seen in PDS and PG.
• Family history: When examining sets of families, around 12% of family members had PDS.

What are the symptoms? 

Many patients do not have any symptoms, particularly in the beginning. As PDS progresses, which can lead to PG, the common symptoms are: 

• Difficulty with side vision
• Sporadic episodes of halos
• Blurry vision

How are PDs and PG diagnosed? 

With both PDS and PG, an ophthalmologist needs to do a thorough examination that may include: 

• Examining the drainage from the eye (as PDS and PG cause more pigment drainage) 
• Testing for pigment granules on the inner lining of the cornea and thinning of the iris
• Imaging of the back of the eye to assess optic nerve damage

What are the treatment options? 

At this time, there is not an effective treatment to eliminate the release of pigment. Some studies have found vigorous exercise, like basketball or running, can cause more pigment to be released. Exercise should not be fully eliminated, but you should discuss with your doctor how to modify your physical activity.

The current treatment options are similar to open-angle glaucoma and mainly focus on reducing eye pressure, which includes medication and laser treatment. 

Medication

• Eye drops, such as Betagan, Timoptic, and Xalatan, have a low incidence of side effects and are generally used for younger patients. 

• Miotics, like Pilocar and Ocusert, constrict the pupil and prevent the iris from rubbing against the supporting fibers of the lens and, thus, prevent further release of pigment. Side effects do include blurred vision, which limits their use. 

Laser treatment 

• Laser trabeculoplasty opens up the drainage system in the eye to increase fluid flow, which improves IOP and protects the optic nerve.

• Laser iridotomy creates a small hole in the iris and causes the iris to move away from the lens, which leads to decrease rubbing against the lens. This surgery option tends to be less effective and is not used as often. 

Additional information on pigmentary glaucoma and pigment dispersion syndrome can be found on the BrightFocus Foundation and Glaucoma Research Foundation websites.

*Ramulu, P. (2020, Apr. 5). Pigmentary glaucoma and Pigment Dispersion Syndrome. American Academy of Ophthalmology EyeWiki. https://eyewiki.aao.org/Pigmentary_glaucoma_and_Pigment_Dispersion_Syndrome