GLAUCOMA

What is Glaucoma?
Glaucoma is a condition in which the internal eye pressure is high enough to cause damage to the nerve that transmits signals of images that we see to the brain(optic nerve). The upper limit of normal for internal eye pressure is generally taken as 21mm Hg. However, this upper limit may vary from person to person and at times pressures below this level may even be harmful to the optic nerve.

Some Health Statistics
Glaucoma affects about 6% of the Singapore population and accounts for 40% of blindness in Singapore. There are an estimated 70 million glaucoma sufferers world-wide with 7 million blind from glaucoma. The risk of glaucoma increases with age and with a positive family history.

Types of Glaucoma
Glaucoma may be congenital, appearing at birth, or it may come later in juvenile or adult life. The adult type usually occurs after the age of 40. Apart from age of presentation, there are generally 2 big groups of glaucoma, namely the chronic and acute type.

Chronic Glaucoma
The chronic type runs a silent, gradual, painless course and without an eye examination, it may go undetected for many years until the glaucoma sufferer loses some part of his field of vision. The field loss starts in the periphery and in advanced cases, one may be left with a central tunnel vision. This is why the chronic type is called the “silent thief of sight”. This type occurs in about 6% of Singaporeans. It is sometimes associated with diabetes and myopia, and may even run in families.

Acute Glaucoma
This type of glaucoma occurs very suddenly as an attack of severe eye pain with poor vision, nausea, vomiting and headache. The patient usually has to be hospitalised for treatment with medications, laser and/or surgery. Once the attack is broken, eye pain is relieved but the chance of visual recovery depends on the length of time before medical treatment is given. The longer the time the internal eye pressure remains high, the poorer the chance of regaining sight. The acute type is more commonly seen in elderly Chinese females.

How do I know if I have Glaucoma?
As the chronic type is silent, the only way to detect it is by regular eye checks after the age of 40 as it tends to start after this age. This is even more important for relatives of a glaucoma patient. Community eye screening is the key to early detection and treatment of chronic glaucoma. When tunnel vision is present at the time of medical attention, this is indicative of an advanced stage of the disease and a poor chance of visual recovery. For the acute type, there is very little way of knowing when an attack is imminent unless a routine eye check shows that one is prone to developing an attack. When this is discovered by your doctor, a laser procedure may be performed to prevent an attack from occurring. Regular eye checks may help prevent attacks in certain types of eyes.

Is there a cure for Glaucoma?
There is no permanent cure for the chronic type of glaucoma in that the internal eye pressures need to be controlled within a “safe” range that is not harmful to the optic nerve. The control of eye pressure can be achieved with the use of eye-drops, laser or surgery, depending on the severity of the disease at the time of diagnosis. The acute type may be treated with a laser procedure but if the eye pressure creeps up over time, medications or surgery may be needed later. Your doctor will discuss all the possible forms of treatment with you.

Take-home Message
Early detection of glaucoma from regular eye checks may help prevent blindness. If treatment is started in the early stage of the disease, a glaucoma patient can continue to enjoy a normal healthy lifestyle.