The pressure behind glaucoma…

The diagnosis of glaucoma is made when your specialist notices a certain type and pattern of damage at the optic nerve – the nerve connecting the eyeball to the brain. This can occur with or without increased pressure inside the eye.

Glaucoma is a progressive and irreversible disease, so specialised testing is incredibly important to monitor any changes.

Damage occurs to the nerves at the back of the eyes and is first noted to those nerves responsible for your peripheral (side) vision.  Because your central vision remains unaffected, symptoms are not usually noted until the disease is severe.  For this reason, glaucoma is often referred to as ‘the silent stealer of vision’ .

Glaucoma care

Pressure in the eye is normal to help maintain it’s shape.

A normal intraocular pressure (IOP) ranges between 10 and 21 mmHg (millimetres of mercury).  Although this range is considered ‘normal’, pressure is also based on each individual.  Your ideal IOP is a pressure that does not cause you damage.

Once your eye has been comprehensively assessed, your specialist will be able to determine what a safe range and target pressure is to best suit your eye and preserve your vision.

The most common cause of glaucoma is an increase in IOP, or the IOP in your eye is not at a safe level for you.

Sometimes, the structures in the eye responsible for the drainage of IOP can be slightly narrowed, causing resistance and not allowing a constant outflow.  This is called closed-angle glaucoma.  Your specialist will assess these structures to determine if that is the case and treat it accordingly.

In the common case that these drainage structures are open and there is no obvious blockage, it is called open-angle glaucoma.  This cause of an increase in pressure is not fully understood, however can be strongly linked to a family history.

On the rare occasion, there may be particles in the eye, some like dandruff or extra pigment, that get stuck in the drainage system and cause spikes of increased pressure.  Some examples are pigmentary glaucoma and pseudoexfoliation.

Glaucoma care

To confirm the diagnosis, assess your risk or review your progress and treatment plan, the eye pressure and optic nerve need to be monitored.  How often you require to be reviewed depends on your stability.  A number of tests are required to be carried out in our clinic and include:

  • Measuring your intraocular pressure (IOP)
  • Visual field test – Assesses your peripheral, or side vision
  • OCT scan – Assesses the health of the optic nerve and the thickness of all the fibres in minute detail.  It also documents and assesses any change or damage over time
  • Photo – A photo of the back of the eye further helps document change and progression in your eye’s condition and health
  • Corneal thickness measurement – Can affect the interpretation of your pressure measurement
  • Gonioscopy – Assesses the drainage in your eyes This is to assess the drainage area in your eye and which impacts on your pressure
  • Dilated eye exam – A comprehensive check of the back of your eye to assess for any damage

Some of these tests do incur an out of pocket cost not covered by Medicare.  Some private healthcare providers may cover this expense dependent on you extras.  You will be informed of all your out of pockets costs prior to undertaking any testing.

As glaucoma is progressive and the effects are irreversible, treatment cannot recover what has been lost, but is aimed at preserving your vision and avoiding further damage.  This is why it is so important to detect the problem as early as possible, to be able to start treatment with as little damage to vision as possible.

The goal of treatment is to lower the eye pressure to best suit your eye to minimise the risk of further damage to the optic nerve.  This can be accomplished by using eye drops, undergoing laser or surgery.  Each classification of glaucoma has its own treatment plan.  Unfortunately, because there has not yet been a definite cure discovered, treatment is for life.

Your specialist will be able to guide you through your treatment plans, options, possible side effects and what is best for you.

It is important to remember that because glaucoma has no symptoms and does not affect your central vision, you will not notice a change in your vision whilst on treatment.

Fortunately, if detected early and treatment is adhered to, blindness unlikely.  Blindness does occur in approximately 5% of patients, however usually occurs when the diagnosis is made late and the disease is already advanced. the diagnosis is made late, when the disease is already advanced.

The one person that has the biggest impact on your sight is you.  By correctly following instructions given by your doctor, you will improve your chances of a positive outcome.

Contact Specialist Eye Surgeons