Glaucoma

Glaucoma is a disease of the optic nerve where nerve fibres in the optic nerve are slowly damaged.  This can lead to a loss of peripheral vision.  If glaucoma is very advanced it can lead to blindness.

The optic nerve connects the eye to the brain.  It transports the visual information from the retina to the brain.

The most common type of glaucoma is open angle glaucoma.  This is usually asymptomatic.  It gives no hint of its presence until visual loss is severe.

Glaucoma is common.  It is more common in older people. It is more common in those with a family history.  People who have had a significant eye injury, diabetes, hypertension and those who are very short sighted, are at higher risk of developing glaucoma.

Acute angle closure glaucoma is more common in Asian people.  It is more common in a small long sighted eye.  It can present with acute pain requiring urgent treatment to prevent visual loss.

The intraocular pressure is the pressure inside the eye that is produced from the regular turnover of aqueous fluid in the front chamber of the eye.  This fluid is produced at the ciliary body and flows around the lens, through the pupil and drains away at the angle of the eye, which is where the iris joins the peripheral cornea.  If the intraocular pressure is elevated, this is a strong risk factor for glaucoma.  Other people may, however, have glaucoma despite a normal intraocular pressure. 

The blood supply to the optic nerve is another important factor in glaucoma. This circulation may be compromised in people with migraine and Raynaud’s phenomenon.

The detection of glaucoma requires; assessment of the eye with vision, measurement of the intraocular pressure, examination of the optic nerve and measurement of the peripheral vision.  The optic nerve can be measured in more detail providing the thickness of the nerve fibres around the optic nerve, which can be an indicator of glaucoma.  The visual field test measures the brightness of light that is detected in the peripheral vision, performed one eye at a time.  These tests are used to diagnose glaucoma and to monitor for any change over time.

The most common form of treatment with glaucoma is with eye drops.  These are derived from many different classes of medication.  Often they are used once or twice daily.  There are some medications where two drugs are combined in the one bottle.  These medications can have side effects that interact with the general health. It is important that a full medical history and medication history is provided to your doctor.

Laser treatment in the form of argon or selective laser trabeculoplasty can be used to treat glaucoma.  The laser is applied to half of the drainage angle of the eye at one sitting and then a further treatment to the other half is performed a few weeks later.  The other eye can be similarly treated. The full effect of the laser occurs about six weeks after the treatment.  When glaucoma is treated with laser therapy, ongoing monitoring is still required.

If glaucoma cannot be adequately controlled with eye drops and laser treatment, then surgery for glaucoma may be performed.  This is generally a trabeculectomy where a small wound is made in the upper part of the eye at the junction of the cornea and the sclera.  This wound allows slow egress of aqueous fluid into the conjunctiva which is then slowly reabsorbed.

Successful glaucoma surgery may result in control of the glaucoma without the need for further eye drops.  The surgery can be complicated by over-drainage or by scarring whereby the drainage area closes over.  If this surgery is being considered for you then further details will be discussed.

As glaucoma is generally without symptoms, it is important to have a regular eye check from time to time.  This is imperative if you have a family history of glaucoma.

If you have persistent pain or sudden change in your vision, report this to the doctor immediately via the Surgery, the Hospital or the Sydney Eye Hospital.

If you have concerns or questions, please call.