March 10th -16th is World Glaucoma Week. The problem with glaucoma is that you don’t feel anything. You don’t even notice anything wrong with your vision until 60% of it is permanently lost.
Vision loss from glaucoma is irreversible – but if caught early can be prevented.
What is glaucoma, exactly?
Glaucoma is a group of diseases that damage the optic nerve at the back of your eye. The optic nerve connects your eye to your brain, allowing you to see.
If it’s not caught and treated, the damage continues to get worse and worse over time. Eventually vision is destroyed. Treatment for glaucoma aims to stop or slow down this damage.
Unfortunately, glaucoma doesn’t usually cause any symptoms until it is very advanced. It has been described as the secret thief of sight. Up to 50% of people that have glaucoma are not aware they have it. (1)
Have you been comprehensively tested for glaucoma?
The trick is to pick it up in the first place. As Dr Alex Koutsokeras of The Eye Practice explains:
I recently saw a patient in his 50s who came in because he was finally ready to admit he needed reading glasses. His arms just weren’t long enough anymore. Before coming to see me, he had never had a proper eye test.
He definitely needed a pair of reading glasses. However, after checking the health of the back of his eyes, I discovered he had advanced glaucoma.
In fact the glaucoma was so advanced that it had destroyed over 80% of his vision in one eye, and 65% in the other.
The reason he didn’t notice the missing vision sooner was because glaucoma damages peripheral vision (side vision) first, only destroying central vision at the very end-stage of the disease.
I started him on treatment immediately, by giving him eye drops to put in his eyes before bed. I also referred him to an ophthalmologist who specialises in glaucoma treatment.
He can never get back the sight he has already lost; but hopefully, with treatment, we can save the sight that he still has.
What does glaucoma testing involve?
Unlike a mammogram for breast cancer or a blood test for diabetes, there’s no single quick test for glaucoma. That’s worth repeating. There is no single quick test for glaucoma. Picking up (or diagnosing) glaucoma involves careful investigation of several aspects of your vision and eye structures. There are at least ten different tests (and often more) that can all build a picture as to whether you have glaucoma or are at risk of this eye disease.
The Eye Practice offers high-level testing for glaucoma. We start by asking you about your risk factors for glaucoma. This includes asking about things like family history of glaucoma, general health problems and medication use.
A higher than normal eye pressure increases glaucoma risk. However, even people with normal eye pressure can develop glaucoma and many people with higher than normal eye pressure do not have glaucoma! Measuring eye pressure does not determine if you have glaucoma or not.
The cornea is the clear front window of the eye. People with a thinner than average cornea are more at risk of developing glaucoma in their lifetime. Corneal thickness takes seconds and is measured by looking at a green light.
3D Optic nerve scanning
Optical Coherence Tomography (OCT) is the latest technology that can detect the earliest damage to the optic nerve, before it has caused any vision loss. It is sophisticated, quick and completely non-invasive. The Eye Practice recommends all patients have a baseline OCT once they reach 40 years of age, and repeat tests every couple of years to look for subtle changes to the internal structure of their eye that could be the earliest signs of glaucoma.
Peripheral vision testing
Early glaucoma does not cause changes to central vision, but can cause small blind spots to appear in the peripheral vision. Patients have no awareness of these blind spots, but they can be picked up on very early with visual field testing.
The gold standard visual field test is the Humphrey Visual Field Analyser by Zeiss. The Eye Practice has the latest version of this instrument here. This means accurate results with shorter testing times, as well as advanced tracking of any changes over time.
How often should I get tested for glaucoma?
Having eye health checks every 2 years can help detect glaucoma early. If you are at higher risk, or have inconsistent results, you may need to have routine checks every 6-12 months.
The risk of glaucoma increases with age. It is especially important for anyone over the age 40 (or over 30 for people of African or Asian descent) to have their eye health checked for glaucoma.
Anyone who has a family member diagnosed with glaucoma should also have a comprehensive eye exam to look for glaucoma, regardless of age.
Had your eyes comprehensively tested for glaucoma recently? See the experts. Call The Eye Practice on (02) 9290 1899 or make an appointment online today.
References: 1. Sommer et al. Arch Ophthalmol 1991; 1090-1095