It isn’t actually a single disease, rather the name ‘glaucoma’ covers a group of disorders that lead to optic nerve damage. Unfortunately, any damage to this important component will lead to vision loss that cannot be restored.
However, if it is diagnosed early enough, treatment can begin and serious loss of sight can be prevented.
The optic nerve is actually part of the central nervous system. It consists of a bundle of more than one million nerve fibres. It transmits any visual information from the retina to the brain, which then processes that information. Therefore, it is crucial for vision.
Open-angle glaucoma is the most common form of the disease – 9 out of 10 sufferers will experience this form of the disorder.
In a typical eye, the iris (coloured part of the eye) meets the cornea (the surface of the eye), with an ‘open angle’ between the two. This allows the clear fluid that sits in this section of the eye, called the aqueous humour, to freely leave the anterior chamber (front section of the eye).
When the aqueous humour reaches the angle, it naturally flows through a spongy meshwork, which acts as a drain, and then moves to the back chamber of the eye. However, if the fluid passes too slowly through the meshwork drain, it can cause the pressure inside the eye to build, which can damage the optic nerve. The result may be open-angle glaucoma – and vision loss.
Not necessarily. If eye pressure increases, you are at risk of developing glaucoma, however, it does not mean that you will definitely acquire the disease. Only if the optic nerve has been damaged will you be diagnosed as having glaucoma.
If there is no damage to the optic nerve despite increased eye pressure, you do not have glaucoma. However, it is important that your eye care professional regularly monitors your situation.
It depends on the individual – not every person with increased eye pressure will develop glaucoma. In fact, some people (or rather their optic nerve) can tolerate elevated eye pressure better than others. A particular level of eye pressure may be high for someone, but be completely normal for another person. This is why regular examinations are important, particularly once you reach the age of 50.
Yes, you can. It is called normal-tension glaucoma which is a form of open-angle.
Everyone – glaucoma does not discriminate. However, some people are at higher risk than others, including:
At this stage, there is nothing definitive that will prevent glaucoma. However, studies show that if you can detect glaucoma at an early stage, before it causes major vision loss, it is possible to control the disease. If you are at a higher risk, it is important that you have an eye examination every two years.
In the early stages, open-angle glaucoma is asymptomatic. There is no pain and vision seems quite normal, so a person goes on with their life not knowing that they are at risk of losing vision.
In fact, without treatment, a person will gradually lose their peripheral (side) vision. It will appear as if they are looking through a tunnel. As the disease develops, centre vision may also decrease until, in the most serious cases, no vision remains.
An ophthalmologist will perform a comprehensive examination of the eyes. The tests include:
Unfortunately, there is no cure for glaucoma. However, ongoing treatment and monitoring the disease on a regular basis can minimise loss of vision.
It is important that, in the early stages of open-angle glaucoma, treatment is sought as it can delay progression of the disease – this is why early diagnosis is extremely important. Glaucoma treatments include:
These treatments are intended to save remaining vision, as they cannot improve sight already lost.
If you are taking any form of medicine to treat the disease, be sure to take them exactly as directed by your eye care professional.
If you haven’t developed glaucoma but are at a greater risk of developing it, you should have a dilated eye exam at least every two years. If you have been diagnosed, you will most likely need to be monitored by your eye care professional on a regular basis.
There are a number of low vision services and devices that can help you make the most of your remaining vision. It is worth noting that, in most cases, a slight loss of vision may not be noticeable. However, anyone who has experience significant vision loss should be referred to a low vision specialist in order to improve their day to day life.
There are a number of agencies and community organisations that offer counselling, training, and other special services for people with visual impairments.
Encourage them to visit their eye care professional at least once every two years in order to have a comprehensive dilated eye exam. Remember that early treatment of glaucoma slows progression of the disease and will help to save valuable vision.