Pigment Dispersion Syndrome Diagnosis and Treatment
Because there are often no symptoms, pigment dispersion syndrome (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.
These tests are the same used for a glaucoma diagnosis and will determine if you have pigmentary glaucoma. Your ophthalmologist will be looking for 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.
Treatment for pigment dispersion syndrome varies depending on how it is affecting your eye pressure (IOP or intraocular 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.
Medicated eye drops
Glaucoma is usually controlled with eye drop medicine. Used every day, these eye drops lower eye pressure. Some do this by reducing the amount of aqueous fluid the eye makes. Others reduce pressure by helping fluid flow better through the drainage angle.
There are two main types of laser surgery to treat glaucoma. These procedures are usually done in the ophthalmologist's office or an outpatient surgery center.
- Trabeculoplasty. The eye surgeon uses a laser to make the drainage angle work better. That way fluid flows out properly and eye pressure is reduced. Even if laser trabeculoplasty is successful, most patients continue taking glaucoma medications after surgery. For many, this therapy is not a permanent solution. Nearly half who receive this surgery develop increased eye pressure again within five years. Many people who have had a successful laser trabeculoplasty have a repeat treatment. Laser trabeculoplasty can also be used as a first line of treatment for some patients who can't use glaucoma eye drops.
- Laser iridotomy is sometimes recommended for people with pigment dispersion syndrome. If their iris bows backwards, this causes the iris to rub against the lens and release too much pigment. A laser creates a small hole about the size of a pinhead through the outer edge of the iris (either at top under the eyelid, or at the side). This allows the iris to become more flat and decreases the amount of pigment floating freely in the eye. This treatment may also help control eye pressure in the early stages of pigmentary glaucoma. But it is not done if much damage to the optic nerve has already occurred. This hole is not visible to the naked eye in most patients.
Operating room surgery
Some glaucoma surgery is done in an operating room. It creates a new drainage channel for the aqueous humor to leave the eye. Two of the most commonly done surgeries are:
- Trabeculectomy. This is where your eye surgeon creates a tiny flap in the sclera (white of your eye). He or she will also create a bubble (like a pocket) in the conjunctiva called a filtration bleb. It is usually hidden under the upper eyelid and cannot be seen. Aqueous humor will be able to drain out of the eye through the flap and into the bleb. In the bleb, the fluid is absorbed by tissue around your eye, lowering eye pressure.
- Glaucoma drainage devices. Your ophthalmologist may implant a tiny drainage tube in your eye. It sends the fluid to a collection area (called a reservoir). Your eye surgeon creates this reservoir beneath the conjunctiva (the thin membrane that covers the inside of your eyelids and white part of your eye). The fluid is then absorbed into nearby blood vessels.