Glaucoma is one of the world’s leading causes of blindness. It is not curable, but blindness is preventable if the glaucoma is diagnosed and treated early enough. While there are usually no warning signs, regular eye tests will help detect the onset of the disease.
Glaucoma is characterised by loss of vision due to damage of the optic nerve. The optic nerve carries sight images to the brain and any damage to the nerve results in damage to sight. Usually, but not always, the damage occurs because pressure within the eye increases and presses on the nerve, which damages it.
The most common is chronic (primary open angle) glaucoma – this form usually affects both eyes and develops slowly so that loss of sight is gradual. There is no pain, redness of the eye or dramatic change in vision.
With acute (angle closure) glaucoma, there is a sudden increase in the pressure within one eye. The eye becomes red and painful. Often there is mistiness of vision and episodes of seeing halos around lights. Sometimes, other diseases of the eye cause a rise in the pressure within the eye – this group of conditions is called secondary glaucoma.
Congenital glaucoma (buphthalmos) is a condition where glaucoma is present from birth. An increase in the pressure within the eye causes it to enlarge.
Many people get glaucoma as they get older, and it seems to be part of the natural ageing process; however some groups of people are known to be at more risk:
If you have been diagnosed with glaucoma, this does not mean you will go blind, especially if you have been diagnosed with glaucoma at an early stage in the disease. When you come to see your ophthalmologist, you are likely to undergo some simple, pain-free tests. The pressure will be measured and a few special investigations will be performed such as visual fields, gonioscopy, optic nerve assessment and perhaps a fundus photograph.
Your doctor will examine the results of the tests, and will use these to help decide on the best glaucoma treatment for you.
Part of the Glaucoma treatment requires that the patient to be followed up every 6 months and visual field should be performed once a year.
Patients with glaucoma rarely lose their sight completely. Providing you receive the correct glaucoma treatment, use the drops or drugs as prescribed, and attend your follow up appointments and checks, the risk of sight loss should be minimised.
Drops, tablets and sometimes operations can stabilise the glaucoma, and, with regular check-ups, you will be able to manage the condition. Any sight you have lost you will not regain. However, there is help and information available for people who have lost their sight through glaucoma. Many optometrist provide, low visual aid facilities, alternatively there are societies such as LOFOB (021 7053753) who can provide information or training.
There are many glaucoma surgeries, and variations or combinations of these surgeries. They mostly work by facilitating the outflow of pressure. Most commonly performed procedures are a Trabeculectomy or insertion of a tube (Ahmed or Molteno) or valve (Express).