An Eye Specialist's Guide to Glaucoma

If left untreated, glaucoma can cause you to lose vision and even become blind. What are its causes and how can we prevent it?

Here’s what you need to know about glaucoma.

1. Glaucoma is often referred to as the 'silent thief of sight'

Glaucoma is a specific group of diseases that damages the eye's optic nerve. It's known as the 'silent thief of sight' because many people with glaucoma experience no early symptoms or pain. In fact, more than 90% of people with glaucoma are unaware they have it until they are officially diagnosed.

2. The condition is usually caused by a build-up of fluid within the eye

Your optic nerve is made up of over a million little nerve fibres, which connect your eye to the brain. If these nerves are put under pressure, it can cause irreversible damage and interfere with the signals responsible for transmitting images. More rarely, poor blood flow (despite normal eye pressure) causes damage to the optic nerve.

If left untreated, glaucoma can lead to permanent vision loss.

3. You could be at risk of glaucoma and not even know it

Several factors can increase your chances of developing glaucoma later in life. These include:

• Raised pressure within the eye
• Your age – the older you are, the higher your risk
• A family history of glaucoma
• Asian, African or Hispanic heritage
• Previous eye injury
• Severe nearsightedness (myopia) or farsightedness (hyperopia)
• Long-term use of steroid medications
• Thin corneas (the transparent layer at the front of your eye)
• Health conditions like diabetes, high blood pressure and migraine

4. There are 2 main types of glaucoma

Glaucoma can be classified as either open-angle or angle-closure.

Open-angle glaucoma is the most common form of the condition, where the angle between the iris (the coloured part of your eye) and the cornea is normal in width. However, the drainage canals become clogged, leading to an increase in eye pressure. Usually, this is a lifelong condition that develops slowly and causes few symptoms in the early stages of the disease.

For angle-closure glaucoma, the angle between the iris and cornea is too narrow, and the access to drainage canals becomes blocked. In some cases, this causes a sudden rise in eye pressure, resulting in symptoms such as eye pain, headache and vision loss.

5. Approximately 5.1 million people in the world have lost their sight from glaucoma

As Singapore's population ages, the number of glaucoma sufferers is rising. Approximately 3% of Singaporeans over the age of 50 have glaucoma, with the number rising to 10% over the age of 70 years.

While cataract is a more common condition, its effect on vision is often reversible, unlike glaucoma. That's why many experts predict that glaucoma may eventually become the most common cause of blindness worldwide.

6. If you catch glaucoma early, the prognosis is usually much better

If glaucoma is diagnosed too late, the vision of the patient will be permanently impaired.

However, if your glaucoma is mild or moderate, your doctor is far more likely to be able to prescribe an appropriate treatment to control eye pressure through medication or surgery, thus preserving your current state of vision.

Treatment options may include:

• Eye drops
• Laser eye surgery
• Glaucoma surgery (trabeculectomy and tube drainage surgery)
• Minimally invasive glaucoma surgery (MIGS)

In a traditional trabeculectomy, your doctor will create a new channel to drain fluid from your eye. While it will not help to restore your sight, this can help to lower the eye pressure and slow down the rate of vision loss in the future.

MIGS is a fairly recent innovation that may be suitable for you if you have mild to moderate glaucoma, and a low tolerance for glaucoma medications. With MIGS, you'll benefit from a faster recovery time and a lower risk of complications.

7. You can prevent glaucoma

The first step is to always go for regular eye screening. If your eye doctor detects a problem, they may be able to prescribe you pressure-lowering eye drops, which will help to keep glaucoma at bay.

If you're concerned about your risk for glaucoma, or if you're experiencing unusual symptoms, make an appointment with an eye specialist.