Pigmentary glaucoma and pigment dispersion
Pigment gives your iris its color. Pigment dispersion syndrome occurs when your iris rubs against the lens and releases pigment. This suspended pigment travels within your eye and coats the trabecular meshwork, the membrane that regulates intraocular pressure. In cases of significant obstruction, spikes in intraocular pressure can occur and damage the optic nerve; this is pigmentary glaucoma.
What is pigmentary glaucoma?
Pigmentary glaucoma is linked to the dispersion of iris pigment (from the iris) when the pupil dilates.
The iris rubs against the lens and loses pigments which become suspended in the eye. This is pigment dispersion syndrome.
The pigment accumulates against the trabecular meshwork, the natural network that allows aqueous humor to drain away.
The more pigment there is, the more it becomes clogged, leading to increases in eye pressure.
When pigment dispersion syndrome damages the optic nerve due to increases in eye pressure, it is called pigmentary glaucoma.
30% of patients with pigment dispersion syndrome develop pigmentary glaucoma during their lifetime.
Symptoms
Pigment dispersion is most often asymptomatic. Some patients complain after intense physical exercise (adrenaline surge dilating the pupil):
With blurred vision.
Luminous halos.
Headaches.
Asymptomatic pigmentary glaucoma
Most often, if you suffer from pigmentary glaucoma, you will not notice any symptoms.
The optic nerve will gradually become damaged and, without ophthalmological consultation, severe damage can develop.
In later stages, as the optic nerve thins, you may notice dark spots (scotomas) beginning to appear in your field of vision.
When all the optical fibers are affected, we speak of blindness.
Who is affected? Risk factors
Pigment dispersion syndrome can be hereditary (passed down from parent to child). It is more common in:
Nearsighted people.
People aged 20 to 30.
Men.
Caucasian patients.
Since pigment dispersion is most often asymptomatic, it is usually detected during a routine eye exam. This is why it is so important to have an eye exam with your ophthalmologist.
During the examination, your ophthalmologist will:
They will check your eye pressure and vision, which are often normal.
You will observe pigment on the inner surface of your cornea.
Will perform a gonioscopy (examination of the trabecular meshwork, the membrane that regulates intraocular pressure).
Your optic nerve will be assessed at the fundus of the eye and in practice an optical coherence tomography (OCT), a device that counts your optic fibers and compares you to patients of the same sex and age.
To go further, he could ask:
A visual field test to assess losses of light sensitivity in parts of vision.
UBM – A type of ultrasound of the eye, allowing the iris to be seen rubbing against the lens.
Treatment for pigment dispersion syndrome varies depending on how it affects your eye pressure and optic nerve:
In the absence of glaucoma and if eye pressure is normal, your ophthalmologist will monitor your eye pressure annually and perform an OCT scan to assess possible optic nerve damage.
In cases of high intraocular pressure, without glaucoma, your ophthalmologist may recommend laser treatment (peripheral iridotomy and/or trabeculoplasty, SLT) to relieve friction between the iris and the lens and reshape the trabecular meshwork. They may also prescribe eye drops to further lower the pressure.
In cases of aggressive glaucoma, in addition to laser treatment and eye drops, the ophthalmologist may need to perform surgery to regulate intraocular pressure: sclerectomy or trabeculectomy.