Glaucoma

Glaucoma - the Sneak Thief of Sight

Glaucoma is a common eye disease - in fact, 2.5% of the population has it. This may not sound very impressive until you consider that glaucoma causes permanent blindness when untreated. The best time to treat it is early in the course of the disease, which is when symptoms are typically non-existent.

Everybody is at risk of developing glaucoma. Its incidence is skewed towards older individuals, but even babies can have it. Your risk is increased if you are diabetic, if you have a family history of glaucoma, or if you take particular medications (such as steroids). There are many other risk factors as well, including short sight, a history of eye injury, and the presence of certain other eye diseases or anatomical variations.

Some people are more at risk of glaucoma than others are. Some of the risk factors for glaucoma include:
- A family history, particularly if the person with glaucoma is a sibling or parent.
- Myopia
- Diabetes
- Regular medications such as oral steroids
- Sleep apnoea (heavy snoring, intermittent cessation of breathing overnight)
- Regular migraine headaches
- Cataracts – some swelling cataracts “lean” against the drainage system in the eye
- Being a human being (nobody is immune)

At ICU, we take a three-way approach to glaucoma screening:

1. We measure eye pressures in all post-primary-school-age patients, every 2 years.
This is a quick and simple test which involves some drops in the eyes. We don’t like the “puff” test for pressures so this instrument is not used, and the drops do not dilate your pupils, so you’re fine to drive afterwards. The mild “numbing” effect of the drops lasts for only 10-15 minutes.

2. We take photographs of the appearance of the optic nerve in all patients old enough to sit still at the camera. The head of the optic nerve can be likened to a “doughnut” at the back of the eye. It represents the cable that takes visual messages from your eye to your brain. In glaucoma, the hole in the doughnut gets bigger over time, and the most accurate way to assess this is by comparing old and new photographs on a regular basis.

3. We perform regular peripheral vision testing for all adults. In perimetry, or peripheral vision testing, we ask you to sit at a computerized instrument which then flashes lights around its bowl. Your job is to register each light you see with a click of a button. The instrument then maps how sensitive you are across your peripheral vision. The test lasts for 3 – 5 minutes for each eye. This test is best performed regularly, because when people get rusty at it, we get results that don’t make sense.

In summary, glaucoma is common, sneaky, blinding and treatable if you know it’s there. Early detection is essential to preserve your sight for a lifetime. Ensure your eyes are checked regularly, particularly if you know you have at least 1 risk factor for glaucoma.