You have been diagnosed as a ‘glaucoma suspect’ patient. Fortunately this means you do not have glaucoma, but you have some features that may indicate the condition.

This could mean that either:

• the state of your optic nerve, which starts at the back of the eye, may indicate glaucoma
• your visual fields (side vision) are abnormal
• there is raised pressure in your eye (a risk factor for glaucoma)
• you have a family history of glaucoma

OR You may have a combination of these factors.

The optic nerve can vary a lot in appearance from one person to the next. This means it is sometimes difficult to know whether someone’s optic nerve is normal or abnormal. If the appearance of the nerve does not change over time, it is likely that it is normal for you. However, if there is a change it may suggest a progressive (worsening) disease like glaucoma. Some ways that the optic nerve may suggest glaucoma

Is my optic nerve normal or abnormal?

High myopic (short sighted) patients have longer eyeballs than others, and their optic nerves can look like they are damaged but the appearance can be normal for your eye.

Sometimes the optic nerve can enter the back of the eyeball at an angle rather than straight on. They therefore look tilted from the top. This can give the impression that the tilted side of the nerve head is thinner than the rest. (The optic nerve head is the beginning of the optic nerve that is visible at the back of the eye.) Even though this is unusual, this is normal for that eye.

Occasionally patients look like they have a bigger nerve head at the back of one eye compared with the other. This can give the impression that the larger nerve head has fewer nerve fibres than the smaller one, but again this is normal for each eye.

The visual field test measures how much peripheral (side) vision each eye has. A visual field test takes some time to understand and do properly. There is usually a learning curve. This means visual field test performance can get better over time. There are other factors that can cause a defect in your visual field other than glaucoma, such as your eye prescription, tilted discs, the upper lid coming down during the test, or other eye / optic nerve conditions

We will monitor the appearance of your optic nerves regularly using:

• examination of your eyes with specialised instruments and lenses
• photographs or scans of the nerve at the back of your eyes to help detect any subtle changes
• eye pressure checks
• visual fields tests to ensure your peripheral vision is not reducing.

If there is a detectable change in the appearance of the optic nerve, we will discuss this with you and consider treatment or further observation.

If we do diagnose glaucoma, it can be treated by daily eye drops, laser treatment, surgery or a combination of different treatments to reduce the eye pressure.

Mild pigment dispersion is common with normal ageing. More severe pigment dispersion is often, but not always, associated with elevated intraocular pressure, although it may be present for many years before the eye pressure starts to rise.

Glaucoma associated with the pigment dispersion syndrome or ‘pigmentary glaucoma’ is a form of secondary open angle glaucoma.

The inherited condition is relatively uncommon, tends to occur at a younger age than is usual in primary open angle glaucoma, and mainly affects myopic men.

It most often begins in the twenties and thirties, which makes it particularly important to monitor to ensure a lifetime of normal vision.

Nearsighted patients are more typically afflicted. The anatomy of the eyes of these patients appears to play a key role in the development of this type of glaucoma. Let us examine why.

It is thought that due to the anatomy of the eye, there is some contact between the iris (the part of your eye that forms the pupil), and the lens and its associated structures, so that there may be chafing or rubbing during normal activities such as focusing the eyes in order to read.

There is also a possibility that vigorous exercise can cause increased pigment release. Thus some patients are advised to take medications to lower eye pressure prior to exercise or avoid exercise altogether. If you have PDS and are concerned about this, please speak to us before starting or stopping any exercise program.

The pigment that is released can deposit on various structures in the front of the eye, and eventually can clog the drainage system. Some people’s drainage systems do not have a problem handling this extra pigment, and these patients do not develop glaucoma. Other people’s drainage systems cannot handle this extra “load,” and eye pressure builds up or is deposited on the back of the cornea, the surfaces of the lens, and on the drainage meshwork eventually leading to the development of glaucoma. It is estimated that 30-35 percent of patients with pigment dispersion syndrome develop high eye pressure and/or glaucoma.

Normally, clear fluid which is secreted into the eye escapes via the drainage meshwork and returns to the bloodstream. Obstruction of this meshwork appears to account for the raised intraocular pressure, and pigmentary glaucoma behaves in general like primary open angle glaucoma not accompanied by the pigment disturbance.

Typically many patients do not have symptoms, especially early in the disease process. When pigmentary glaucoma advances, a patient may notice difficulty with side vision, just as one would experience in open-angle glaucoma. Rarely, patients may complain of sporadic episodes of haloes or blurry vision. In order to be diagnosed with pigmentary glaucoma, your ophthalmologist needs to do a thorough examination of your eyes, including an examination of your drainage angle.

Patients with pigment dispersion or pigmentary glaucoma have more pigment than usual in the drainage angle. They may also have pigment on the inner lining of the cornea and thinning of the iris from where the iris chafing occurs and pigment is released. A detailed examination of the back of the eye is also needed in order to assess if there is any optic nerve damage. You may undergo imaging of the optic nerve as well as formal field of vision testing.

Medical treatment of pigmentary glaucoma is similar to treatment for primary open angle glaucoma. We will advise on the treatment which is best for you, which may involve eye drops, laser treatment or sometimes surgery.

There are differing opinions as to the usefulness of a laser procedure to make a small hole in the iris,which is usually used to prevent or treat angle-closure glaucoma. In the case of pigmentary glaucoma, the purpose of the hole is to help shift the anatomy in the eye so that there is less chafing or rubbing of the iris and thus less pigment dispersion.

A different type of laser (laser trabeculoplasty) can also be used to improve drainage and lower pressure, which can be very effective in pigmentary glaucoma because of the increased pigment in the drainage angle. Finally, surgical options such as trabeculectomy or tube shunt surgery can also be used to treat more aggressive forms of pigmentary glaucoma

Since pigmentary glaucoma can have no symptoms, and because it typically occurs at a younger age, this form of glaucoma is often underdiagnosed. However, if identified early and treated appropriately, patients often do well, and blindness from this form of glaucoma is relatively rare. In some cases there is the possibility of regression of the pigment dispersion over time, and sometimes there is even a return to “normal” eye pressures. As always, with any type of glaucoma, regular follow-up examinations is critical to the preservation of sight.