What is Glaucoma?
Glaucoma is Singapore's most common cause of permanent blindness. Many call it the “Silent Thief of Sight" because it can steal your vision away without you even knowing it - quietly, painlessly and irreversibly. Glaucoma is a disease that affects the most important structure in your eye: the optic nerve. The nerve is essentially an 'electrical cable' which transmits signals from the eyeball to the brain thus allowing you to see. In glaucoma, the optic nerve is damaged from a variety of causes.
What causes Glaucoma?
There are several types of glaucoma and each causes optic nerve damage in its own way. If you have been diagnosed with glaucoma, you should ask your doctor which type you have.
What are the types of Glaucoma?
Open angle glaucoma
The eyeball's drainage system slowly becomes defective, leading to high pressure within the eyeball (high intraocular pressure). This is the most common form and it is painless.
Close angle glaucoma
The eyeball's drainage system (called the angle of the eye) physically closes up (slowly or suddenly), leading to high intraocular pressure. This can be painful, especially the sudden, acute version.
Low pressure glaucoma
The optic nerve itself is so weak in these patients that it gets damaged with normal eyeball pressures. This variety is also painless.
High eyeball pressure can possibly be caused by other eye conditions like diabetes, cataract, inflammation and some forms of eye surgery. In rare cases, children may be born with defective drainage systems causing congenital glaucoma.
These patients have not been proven to have glaucoma. Some may have high eyeball pressure without any detectable nerve damage. Others have weak-looking optic nerves, but no definite loss of vision.
What are the Signs and Symptoms of Glaucoma?
There are two broad classes of glaucoma:
- Chronic glaucoma causes very slow and painless reduction of vision (majority of cases).
- Acute glaucoma causes severe, sudden eye redness,
pain and blurring of vision.
Unfortunately, most glaucoma patients suffer unknowingly from the chronic form which is painless, and only realize they have glaucoma when the disease is already quite advanced.
There are NO VISUAL SYMPTOMS in early glaucoma.
By the time glaucoma causes any visual problems, there is already severe and advanced damage to the optic nerve. That is why regular eye check-ups are so
important for older people and those with a family history of glaucoma.
Your eye doctor may be the only person who can tell you if you have glaucoma. He or she can do so in the following ways:
- By checking your eyeball pressure.
- By examining the appearance of your optic nerve.
- By using a computer to test your visual field.
- By using high resolution imaging of the optic nerve.
How will my eye doctor treat my Glaucoma?
Glaucoma is a lifelong disease which can only be controlled but not cured. In addition, any damage to the optic nerve that has already occurred cannot be
reversed. The aim of treatment is to prevent further damage and preserve remaining vision.
Once diagnosed, a patient requires strict follow-up with his eye doctor for the rest of his life. Your eye specialist will usually focus treatment on lowering your eyeball pressure by one or more of the following methods:
For most people, eye drops are sufficient to control the disease. They work in a number of ways, but mostly by lowering your eyeball pressure.
There are two different types of laser treatment for glaucoma. One type is used to prevent the acute form of glaucoma in close angle glaucoma. The other type is to lower eyeball pressure in open angle glaucoma. These types of laser are not to improve vision.
Eye surgery is usually the last resort when the above methods have failed.
How can I Prevent Glaucoma?
Unfortunately, glaucoma is not a preventable disease. The best way to combat it is to detect it early. You can do this by going for regular eye checks, especially if you belong to one of the following groups:
- You are over 40 years of age and you have not had your eyes checked regularly.
- Someone in your family already has glaucoma.
- You have diabetes or high blood pressure.
- You are very short-sighted or long-sighted.
You can be assured that with regular eye checks, there would be a better chance of detecting glaucoma early and preventing it from stealing your vision.