Contrary to popular opinion, glaucoma is not a single disease but is instead made up of many different diseases with a single thing in common: damage to the nerve that connects the eye to the brain, otherwise known as the optic nerve, which results in a gradual loss of vision. Like all nerve damage, this damage is often irreversible and can lead to permanent blindness in some advanced cases. It is for this reason that glaucoma is responsible for 40 per cent of blindness in Singapore.
Primary open-angle glaucoma accounts for the majority of all glaucoma cases and tends to affect the middle-age and elderly. Typically, there are no early warning signs of painful symptoms in open-angle glaucoma. This form of glaucoma tends to develop slowly and often without noticeable sight loss for many years. This is because the initial loss of vision usually occurs only in peripheral vision: as such, visual acuity is often maintained until late in the disease.
In contrast, angle-closure glaucoma ia caused by blocked drainage canals in the eye, resulting in a sudden rise in intraocular pressure (i.e. the pressure between the eye and the rest of the head). Symptoms may include hazy or blurred vision, rainbow-coloured circles appearing around bright lights, severe eye or head pain, nausea or vomiting, and sudden loss of vision. Angle-closure glaucoma is a rarer form of glaucoma that develops very quickly and demands immediate medical attention. It is usually affects elderly and middle-age Chinese women in Singapore, but other members of the population nay be affected by it as well.
Another category of glaucoma is known as childhood glaucoma and their symptoms often vary. In some cases, children will show non symptoms; in others, on the other hand, there is gradual onset of problems such as light sensitivity, corneal opacification (where the cornea starts to turn hazy-grey), enlarged eye and cornea, epiphora (overflow of tears), and vision loss.
Your risk of developing glaucoma increases once you are over 50 years old and continues to rise as you grow older. In Singapore, glaucoma affects about three per cent of those aged above 50 and 10 per cent of those aged above 70. Chronic diseases such as diabetes and high-blood pressure has also been known to increase your chances of developing glaucoma, and simoly being Asian or afro-Carribean also makes you more susceptible to certain types of glaucoma (as compared to Caucasian).
Individuals who have extreme near- or short-sightedness are also more likely to develop glaucoma, as are those who have a family history of glaucoma, have sustained eye injuries before or a history of steroid use.
Although glaucoma cannot be cured, it can be successfully controlled in most cases. Tje mode of treatment depends on the type and severity of glaucoma, but some common treatment modalities include medication, laser therapy or surgery. The most important thing is to have it diagnosed early as damage to the optic nerve is irreversible; the longer one waits to get treatment, the more difficult it would be to treat the condition, and the more severe the loss of vision would eventually become.