Glaucoma is often called the “sneak thief of sight”, and the name is earned. The most common form of the condition causes no pain, no redness, and no change in your central vision until it has already stolen a significant portion of your peripheral sight. By then, the damage is permanent.
Glaucoma is the leading cause of irreversible blindness in Australia. Approximately 300,000 Australians have it, and an estimated 50% are undiagnosed. That means right now, roughly 150,000 Australians are losing their peripheral vision without knowing it.
The “Sneak Thief of Sight”
Most people, if asked to describe glaucoma, would mention eye pressure or blurry vision. In reality, the most common form, primary open-angle glaucoma, typically presents with no symptoms whatsoever until 30–40% of peripheral vision has already been lost. The vision loss occurs so gradually and symmetrically that the brain compensates, filling in the gaps. By the time something seems wrong, the damage is extensive.
This isn't a rare fringe condition. The prevalence of glaucoma rises sharply with age: approximately 1 in 200 Australians under 50 have it, rising to 1 in 8 over the age of 80.
How Glaucoma Damages Your Vision
Glaucoma is a disease of the optic nerve, the cable that transmits visual signals from the retina to the brain. In most cases, elevated intraocular pressure (IOP) causes mechanical stress on the optic nerve fibres, leading to progressive damage and death of nerve cells. Once these cells die, they do not regenerate. The vision they were responsible for is gone permanently.
The vision loss typically begins in the peripheral (side) field, advancing inward in a pattern described as “tunnel vision” in severe cases. Central vision, the sharp, detailed vision used for reading and face recognition, is often preserved until very late in the disease, which is why people don't notice the problem until it's advanced.
It's important to know that in normal-tension glaucoma, optic nerve damage occurs despite eye pressure that falls within the statistically “normal” range. This is why pressure testing alone is not sufficient to rule out glaucoma.
Who Is at Risk?
While anyone can develop glaucoma, certain factors substantially raise the likelihood:
- Age over 60: The risk increases with every decade. Adults over 60 should include glaucoma screening as part of their annual eye examination without exception.
- Family history: Having a first-degree relative (parent or sibling) with glaucoma increases your risk approximately 8-fold. Glaucoma has a strong hereditary component.
- Elevated intraocular pressure (IOP): The most well-established risk factor, though not universal, pressure is a risk factor, not a diagnostic criterion on its own.
- Thin corneas: Corneal thickness affects both IOP readings and independent risk. Thinner corneas are associated with higher glaucoma risk.
- High myopia (short-sightedness): People with prescriptions of -6.00 or above have significantly elevated glaucoma risk.
- African or Caribbean heritage: Primary open-angle glaucoma is 4–5 times more prevalent in people of African heritage, and tends to develop at a younger age.
- Diabetes: People with diabetes have approximately twice the risk of developing glaucoma.
- Long-term corticosteroid use: Prolonged use of steroid eye drops, inhalers, or oral steroids can raise intraocular pressure in susceptible individuals.
“I always ask patients about their family history. If a parent had glaucoma, I want to see that patient annually and examine their optic nerve carefully, even if their pressure is completely normal. The optic nerve tells a story that eye pressure alone doesn't.”
, Dr Zobaida Tahiri, Therapeutically Endorsed Optometrist, Auburn NSW
The Problem With Eye Pressure Tests Alone
Many Australians believe they have been “tested for glaucoma” because a device has blown a puff of air into their eye (non-contact tonometry). This test measures intraocular pressure, but eye pressure alone is not a reliable screening tool for glaucoma for two reasons:
- Up to 40% of people with glaucoma have normal eye pressure (normal-tension glaucoma). Their optic nerve is being damaged despite pressure readings that fall within the standard range.
- Many people have elevated pressure without any optic nerve damage (a condition called ocular hypertension). High pressure alone does not mean you have glaucoma.
A proper glaucoma assessment requires examination of the optic nerve itself, not just a pressure check. This is where modern diagnostic technology makes a decisive difference.
What Does Glaucoma Detection Actually Involve?
At Prime Optometrists Auburn, a glaucoma assessment includes:
- OCT of the optic nerve and retinal nerve fibre layer (RNFL): Optical Coherence Tomography can detect thinning of the nerve fibre layer, a structural sign of early glaucoma, often years before any visual field loss occurs. This is the most sensitive early detection tool available. Learn more about our diagnostic imaging technology.
- Visual field testing (perimetry): A computerised test that maps your full visual field, detecting the characteristic patterns of vision loss associated with glaucoma.
- Optic nerve head assessment: Detailed clinical examination of the optic disc, looking for changes in the cup-to-disc ratio, neuroretinal rim thinning, and disc haemorrhages.
- Intraocular pressure measurement: Using Goldmann-equivalent tonometry, with corneal thickness measurement (pachymetry) to contextualise the reading.
- Gonioscopy when indicated: Examination of the drainage angle to distinguish open-angle from angle-closure glaucoma.
Medicare covers annual glaucoma assessments for patients who are at elevated risk, including those with a family history, elevated IOP, or other risk factors. Book a glaucoma check at our Auburn clinic and we'll confirm your Medicare eligibility.
How Is Glaucoma Treated?
Glaucoma is not curable, but it is very manageable, and the goal of treatment is to halt or significantly slow progression. Options depend on the type and stage of glaucoma:
- IOP-lowering eye drops: First-line treatment for most patients. Prostaglandin analogues, beta-blockers, and other agents reduce eye pressure by either decreasing fluid production or improving drainage.
- Laser treatment (SLT): Selective laser trabeculoplasty can improve drainage and lower IOP with minimal side effects. Often used when drops alone are insufficient or not tolerated.
- Surgery (trabeculectomy or tube shunt): Reserved for advanced or treatment-resistant cases, performed by an ophthalmologist.
As a therapeutically endorsed optometrist, Dr Tahiri is qualified to prescribe IOP-lowering eye drops, meaning patients with early glaucoma or ocular hypertension can be managed and monitored at our Auburn clinic, with onward referral to an ophthalmologist when required.
The Good News: Early Detection Works
The reason we emphasise early detection is simple: it works. People whose glaucoma is detected in the early stages, before significant visual field loss, can, with appropriate management, maintain functional vision for life. The damage that has occurred cannot be reversed, but progression can be stopped.
For anyone with risk factors, particularly a family history of glaucoma, age over 60, or high myopia, an annual comprehensive eye examination including optic nerve OCT is one of the most important things you can do for your long-term health. For what to expect from a full eye examination, see our guide: How Often Do You Actually Need an Eye Test?
Book a Glaucoma Check in Auburn NSW
Prime Optometrists is located in Auburn NSW 2144 and sees patients from across Western Sydney, including Lidcombe, Parramatta, Granville, Berala, Regents Park, and Strathfield. We have OCT imaging on-site and offer comprehensive glaucoma assessments with bulk billing for eligible Medicare patients.
If you have a family history of glaucoma, haven't had your eyes tested in the past year, or are simply overdue for a check, please don't wait for symptoms. Book a glaucoma check at Prime Optometrists Auburn, the earlier we look, the more we can protect.