glaucoma testing

How do I know if I have glaucoma?

In day-to-day life, glaucoma is difficult to detect. In fact, 50% of people with glaucoma in Australia go undiagnosed. Yet glaucoma is the leading cause of irreversible blindness worldwide and affects an estimated 300,000 Australians. So, knowing if you have glaucoma is the first critical step in protecting your vision.

“Glaucoma is the silent vision stealer as it progresses slowly causing irreversible blindness without symptoms”.

What happens if you have glaucoma?

Glaucoma ultimately results in damage to your optic nerve which carries vision signals from your eye to your brain. This damage is mostly caused by excessive eye pressure (known as intraocular pressure) which occurs when the eyes natural drainage system malfunctions or becomes blocked.

glaucoma affected vision

Does glaucoma progress fast or slow?

Glaucoma can occur both slowly and rapidly depending on the type of glaucoma:

  • Slow acting glaucoma (Open angle glaucoma) - This is the most common form of glaucoma. Which is why many don’t realise they have an open angle glaucoma as there are no symptoms until there is some loss of vision. This is usually in the form of lost peripheral vision.
  • Fast acting glaucoma (Angle-closure glaucoma) - While rarer, this form of glaucoma happens rapidly and must be dealt with quickly to avoid vision loss. There are however more noticeable symptoms such as headaches, eye pain, and blurred vision to prompt you into action.

Can glaucoma occur without increased eye pressure?

Yes, a low-tension glaucoma can occur when the optic nerve is naturally fragile, so it is important when being tested for glaucoma that you don’t rely only on a test for eye-pressure (tonometer) but also test the condition of the optic nerve.

What are other types of glaucoma?

While rare, childhood glaucoma is noticeable by enlarged cloudy eyes that water excessively.  A secondary glaucoma can also occur as a result of eye injury, eye surgery or some steroid medications which can increase eye pressure.

What causes glaucoma?

It is unknown what specifically causes glaucoma; however, the following factors have been known to increase the risk:

  • A family history of glaucoma
  • High eye pressure
  • Aged over 50
  • Of African or Asian descent
  • Have diabetes
  • Short or long-sightedness
  • Had a prolonged course of cortisone (steroid) medication
  • Experienced migraines
  • Had an eye operation or prior eye injury
  • Have a history or high or low blood pressure

How is glaucoma diagnosed?

Given there are multiple aspects to glaucoma, a collection of tests are needed to provide a full diagnosis. This allows for the most effective and accurate treatment to be applied.

  • Testing eye pressure - this is done using a tonometer. It is a simple, effective and painless test that detects InterOcular Pressure (IOP). Normal eye pressure ranges from 10-21 mmHg (millimetres of mercury). Most people with glaucoma have an IOP of greater than 21 mmHg.
  • Testing peripheral vision - Knowing if peripheral vision has been lost can indicate the potential impact of glaucoma and also how quickly it has progressed. A visual field test will flash a light at various points in the periphery of your vision to record how far your field of vision extends.
  • Check retinal nerve fibre layers – An Optical Coherence Tomography (OCT) scans the fibres surrounding the optic nerve and can detect early signs of glaucoma before vision is affected.
  • Examination of the optic nerve – An Ophthalmoscopy is a visual test to look at the optic nerve itself and detect any signs of nerve cell loss. Imaging can also be done to track progress of glaucoma prior to and during treatment.
  • Checking the eye drainage system – Knowing if the eyes drainage system (known as the drainage angle) is open, narrow or blocked will help diagnose the type of glaucoma present. A Gonioscopy examines the drainage angle in the eye and if it is closed (closed angle glaucoma) urgent action is required to prevent vision loss.

The importance of a regular eye exam

If you match any of the glaucoma risk criteria, having a regular eye exam will ensure you catch glaucoma early. While there is no cure for glaucoma, there are effective treatment options from eyedrops to surgery to prevent further development of glaucoma and protect your precious vision.

Envision Eye Centre is a boutique Ophthalmology practice in Sydney CBD. Our team can diagnose if you have glaucoma and undertake the appropriate treatmentBook an appointment with us to properly diagnose and treat glaucoma so this silent stealer of vision does not impact your life.

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