Clear fluid is constantly produced in your eye, which in a healthy eye drains through a small drainage canal at the front of the eye. When the fluid produced does not match the amount of fluid drained through the ducts, the pressure inside the eye rises and causes damage to the optic nerve, leading to glaucoma. Damage to this nerve, which connects the eye to the brain, leads to irreversible vision loss. Glaucoma usually progresses so slowly that there are no warning symptoms until irreparable damage to the eye has occurred. Regular eye examination is essential to diagnose and treat glaucoma early and possibly prevent vision loss.
Are there different types of glaucoma?
There are the two main types of glaucoma— primary open-angle glaucoma and angle-closure glaucoma.
In primary open-angle glaucoma, the most common type of glaucoma, the fluid pressure in the eye increases. As a result of the increased pressure, the optic nerve can be damaged and nerve fibres can be lost. Glaucoma that has progressed to the point of blindness can be very disabling. Glaucoma does not affect all people with high eye pressure. It can also affect people with normal eye pressure and is then called normal pressure glaucoma. Glaucoma occurs when the pressure in a person’s eye is too high for a particular optic nerve.
Acute angle closure glaucoma, a less common form of glaucoma, develops suddenly as a result of increased eye pressure.
Who is at risk?
The exact causes of glaucoma are not known, but we do know that a family history of glaucoma, race and advanced age are risk factors. Glaucoma can affect anyone at any age, from infants to the elderly, but it is more common in adults as they age. Trauma and certain underlying conditions such as diabetes, high blood pressure and the use of steroid medications contribute to the development of the disease.
Are there any symptoms?
Primary open-angle glaucoma is a form of glaucoma that develops slowly and without symptoms. People who have normal tension glaucoma may suffer from unexplained severe migraines or headaches. Many people do not know they have the disease until they have already lost a significant amount of their vision. Glaucoma first affects peripheral or side vision, but can also lead to loss of central vision. If left untreated, glaucoma can lead to significant loss of vision in both eyes and even blindness. However, severe eye pain, nausea, redness of the eye, seeing halos or coloured rings around lights and blurred vision are all possible symptoms of acute angle closure glaucoma. This is a life-threatening situation where significant vision loss can occur within seconds.
Can glaucoma be prevented?
Glaucoma cannot currently be prevented. However, if it is detected and treated early enough, it is usually manageable. Medication or surgery can help slow or stop vision loss. However, the vision loss caused by glaucoma cannot be reversed. People who are at risk of glaucoma should have an eye examination every year.