Glaucoma isn’t just one condition – it is a group of diseases that affects either one or both eyes. It occurs when the optic nerve (the nerve that joins your eye and brain) is damaged which results in reduced vision or even blindness. It’s usually caused by fluid building up in the front part of the eye, which increases pressure inside the eye.
Most types of glaucoma have no symptoms in the early stages, so regular eyesight tests are the only way to detect the condition. There are several symptoms that are associated with glaucoma, including:
- The slow loss of peripheral vision
- Halos around lights
- Blurred vision
- Intense eye pain
- Red eyes
- Pain surrounding the eye
There are five types of glaucoma, which includes:
1. Open Angle
2. Angle Closure
4. Normal Tension
5. Glaucoma in Babies and Children
Open angle glaucoma is the most common, with 7 out of 10 glaucoma patients having this type. It develops slowly due to fluid being unable to drain from the eye. It is a chronic condition.
Angle closure can be acute (happens quickly) or chronic (long term). It occurs when the cornea (the clear front of the eye) comes into contact with the iris (the coloured part of the eye). This causes problems with fluid draining. It can cause redness in the eye, severe pain, a halo around lights, blurred vision, and ultimately blindness. If you experience any of these symptoms, it is important to seek urgent medical attention.
Secondary glaucoma follows other eye conditions, such as frequent inflammation or trauma to the eye.
Normal tension is a chronic condition, caused by the optic nerve. This can be due to weakness or poor blood flow to the nerve.
Glaucoma can affect anyone of any age, but is very uncommon in children and babies. Congenital/developmental glaucoma occurs when the eye’s drainage system isn’t formed correctly which causes the baby to be born with glaucoma.
As you can see, the most common cause of glaucoma is an increase of pressure in the eye, often caused by fluid (aqueous humour) in the front of the eye (anterior chamber), not draining correctly. The fluid in your eye is usually regulated by drainage, so the pressure isn’t affected, but if something is preventing this then the optic nerve can be damaged. This results in your eyesight being affected.
Other causes / risk factors of open angle glaucoma includes:
- A weak optic nerve
- Your ethnicity (your chances increase if you are of black-African or black-Caribbean descent)
- Your age; 1 out of 10 people over the age of 70 have glaucoma
- Diabetes (especially type 2)
- Long term use of steroids, especially around the eyes
- High blood pressure
- Cardiovascular disease
- Family history of glaucoma
- Conditions that affect the blood flow to the eyes
Risk factors of angle closure glaucoma includes:
- Your gender; women are more at risk
- Your age; most common age 55-65
- Your ethnicity (your chances increase if you are of asian descent)
- It is related to your eye shape, so could be hereditary
Glaucoma cannot be prevented, but the progression of it can be slowed. 2 out of 10 patients have lost some of their peripheral (outer) vision by the time they are diagnosed. If you are over 40, it is recommended you have an eye test every 2 years. If a close relative has been diagnosed with glaucoma, it is important to get tested regularly, depending on your age.
Age 20 – 29; get checked every 3 – 5 years.
Age 30 – 64; get checked every 2- 4 years.
Age 65+; get checked ever 1-2 years.
If signs of glaucoma are detected during an eye test, other tests are usually needed to diagnose the condition. An eye pressure test is one way to test for glaucoma. An instrument called a tonometer is used to measure the pressure inside the eye. A small amount of anaesthetic and dye is used, and then your optometrist will shine a light into the eye and gently touch the surface with the tonometer.
Another test used is a visual field test, which checks for missing areas of vision in your eyes. A sequence of light spots will be shown to you, and you will be asked to press a button to show the ones you can see.
A gonioscopy is another way to diagnose glaucoma. It can determine whether the area is open or blocked, which affects the way fluid is drained from your eye. This is useful in diagnosing the specific type of glaucoma.
Finally, an optic nerve assessment may be carried out. Eye drops will be used to enlarge the pupils, and then light is used to examine your eyes. If this test is used, it is important to arrange how you will be getting home after the appointment, as your ability to drive may temporarily be affected.
If glaucoma is detected during any of these tests, you will be referred to an ophthalmologist, which is a doctor who specialises in eyes. They will confirm the diagnosis, and undertake more tests to see the extent of any damage that may have occurred, and what possibly caused the glaucoma. After this, it is common to be referred back to your own optometrist for longterm treatment of the condition.
Treatment of glaucoma aims to lower the pressure in the affected eye/s, to prevent any further damage to your sight and to the optic nerve. There are three main treatment options:
- Eye drops; this is the most cost common form of treatment, and for many patients it is the only treatment they will ever have. It is important to use your eye drops as directed, no matter how your vision seems. If not, you may risk losing your sight.
- Laser treatment; this is where a beam of light is aimed at part of your eye, to prevent build up of fluid. Local anaesthetic is usually used, which means you will be awake, but the eye will numbed. You may experience slight pain or a feeling of heat, but it shouldn’t be unbearable. Eye drops can be used in conjunction with this treatment.
- Surgery; this is usually the last form of treatment used, if eye drops and laser treatment hasn’t worked. The most common type (trabeculectomy) involved the removal of part of the drainage tubes to allow fluid to drain more easily from the eye. You will either be operated on under local anaesthetic (you’re awake) or general anaesthetic (you’re asleep). After surgery, it is uncommon to need eye drops, but some patients still do. You shouldn’t be in severe pain following your procedure, but you may experience some discomfort. Your eye may be slightly red and watery, and your vision may be temporarily affected for up to six weeks.
Glaucoma shouldn’t stop your day to day life – in fact regular physical activity often reduces eye pressure! It is advised to check with your GP if you are planning on scuba diving, due to the pressure changes experienced. You may find it helpful to install brighter lights in your home if your vision has been affected.
Make sure you get a regular eye test or book one quickly if you develop symptoms. Community Care Opticians can visit you in your home and carry out a full NHS eye test for free (if eligible). Give us a call now on 0203 418 8488 or visit our website
For more information on glaucoma please have a look at the following websites: