What Is Glaucoma?

What Is Glaucoma?

The Eye Condition Explained

Glaucoma is a common eye condition that can cause vision loss and blindness if it isn’t treated early. But what is glaucoma exactly? We take a look at how it occurs and possible glaucoma treatment options.

What is glaucoma?

Glaucoma is a common eye condition where the optic nerve — the nerve which connects the eye to the brain — becomes damaged.

This is caused by fluid building up in the front part of the eye, which in turn causes pressure inside the eye to increase, damaging the optic nerve. The optic nerve plays a vital role when it comes to sight, because it passes signals from the retina to the brain (which is how we see).

If it isn’t diagnosed and treated early, glaucoma can lead to permanent vision loss and blindness. That’s why it is important to book yourself in for regular eye tests and to ensure that your optician checks for glaucoma.

Glaucoma is most common in people in their seventies and eighties. However, it can affect people of all ages. Very rarely, glaucoma can occur in very young children.

Glaucoma is a general term for a group of eye disorders that damage the optic nerve and cause problems. You can find out more about the main types of glaucoma below.

Glaucoma symptoms

Glaucoma tends to develop slowly over a number of years, so you may not notice any symptoms to start with — or at all. Most people get diagnosed with glaucoma when they go in for a routine eye test.

However, there are some glaucoma symptoms you can look out for:

  • Problems with peripheral vision (blurring)
  • Blurred vision
  • Seeing rainbow-coloured circles or rings around bright lights

Rarely, glaucoma can develop suddenly, which may result in the following signs and symptoms:

  • Intense eye pain
  • Headaches
  • Nausea
  • Vomiting
  • Tenderness or soreness around the eyes
  • Redness in the eye
  • Blurred vision
  • Seeing rings around lights

If you are experiencing any of the symptoms we have mentioned above or if you have any concerns about your vision, it is best to visit an optician or GP. If these symptoms come on quickly, go to your nearest A&E and seek medical attention immediately.

You can find out more about the signs and symptoms of different types of glaucoma on our glaucoma symptoms page.

Glaucoma causes

Glaucoma can occur for a variety of reasons.

The most common reason that is responsible for the majority of glaucoma cases is a build-up of pressure in the eye. This happens when the aqueous fluid in the eye is unable to drain properly, causing a build-up of pressure in the eye. High eye pressure is known as intraocular pressure.

This pressure increase then damages the optic nerve, causing various effects and symptoms of glaucoma, such as loss of sight.

There are a few other reasons why this build-up of pressure can happen, such as high blood pressure, certain medications, or poor blood flow to your optic nerve.

Glaucoma risk factors

There are certain factors that can increase your risk of glaucoma.

Glaucoma risk factors include:

  • Age: glaucoma is more common in people in their seventies and eighties, and your risk increase as you get older
  • Family history: if you have a first-degree family member (a parent or sibling) who has glaucoma, you're more likely to develop it yourself
  • Ethnicity: people of African, Caribbean or Asian origin have a higher risk of glaucoma and are more likely to develop the condition earlier in life too
  • Diabetes: people with diabetes are twice as likely to suffer from glaucoma
  • Eye conditions: short-sightedness can increase your risk of open-angle glaucoma and long-sightedness can increase your risk of closed-angle glaucoma
  • Previous eye surgery or injury: glaucoma may occur either straight after the eye injury or surgery, or could occur years later
  • Long-term use of steroids: using steroids for a long time leads to an increased risk of glaucoma

Just because you fall into one or more of these categories doesn’t necessarily mean that you will develop glaucoma when you’re older.

Having regular eye tests can help to pick up glaucoma as early as possible. Once it has been diagnosed, it can be treated and prevented from worsening.

Does glaucoma affect both eyes?

Most people develop glaucoma on both eyes, although glaucoma can be worse in one eye than the other — especially initially. Glaucoma doesn’t always develop at the same time in each eye.

This can also vary depending on the type of glaucoma you have; open-angle glaucoma can affect one eye severely, while the other eye might only be mildly affected.

How common is glaucoma?

Glaucoma is a common eye condition. It is one of the leading causes of blindness across the world, according to the World Health Organisation.

Glaucoma is more common in older people — particularly those over seventy — and doesn’t affect younger adults or children as much.

About 2% of the British population over 40 are affected by primary open-angle glaucoma, which is the most common type of glaucoma. This rises to around 5% (more than one in 20) in people aged 80 and over.

Glaucoma types

Glaucoma refers to a number of eye conditions characterised by damage to the optic nerve. These various eye conditions can occur due to different underlying causes and don’t all present the same symptoms.

There are five main types of glaucoma. In this section, we’ll go into the differences and similarities between these glaucoma types.

Open-angle glaucoma

Open-angle glaucoma is the most common type of glaucoma, affecting the majority of people who have the condition.

This particular type of glaucoma usually develops slowly over the years. You may not notice any symptoms at all, and only realise you have open-angle glaucoma when you are diagnosed at a routine eye examination.

Open-angle glaucoma is caused by drainage channels in the eye gradually becoming clogged over time.

Open-angle glaucoma may also be called primary open-angle glaucoma.

Closed-angle glaucoma

Also known as acute angle-closure or narrow-angle glaucoma, closed-angle glaucoma is an uncommon version of this eye condition.

Closed-angle glaucoma comes on very quickly and happens when the drainage channels in the eye become blocked suddenly (due to the angle between the iris and cornea being too narrow). This raises the pressure inside the eye extremely quickly and can cause lots of severe and painful symptoms, including headaches and pain in the eye.

This type of glaucoma requires immediate medical attention. If you experience symptoms, go to your nearest A&E straight away.

Normal-tension glaucoma

In some cases, optic nerve damage can develop in people without increased pressure in the eye. This can affect as many as one in three people who suffer from damage to the optic nerve.

Normal-tension glaucoma is sometimes also called normal-pressure glaucoma or low-tension glaucoma

Experts aren’t sure why normal-tension glaucoma occurs. However, it is thought that a lack of blood flow to your optic nerve or extreme sensitivity may play a part in this particular type of glaucoma developing.

Secondary glaucoma

Secondary glaucoma is caused by an underlying health condition or injury to the eye.

There are a few different types of secondary glaucoma, including Fuchs’ dystrophy, pseudoexfoliation syndrome and iridocorneal endothelial (ICE) syndrome.

For the majority of cases, secondary glaucoma only occurs in one eye, but it can sometimes affect both eyes.

Congenital glaucoma

Also known as childhood or paediatric glaucoma, congenital glaucoma is a rare type that only affects very young children

This is caused by an abnormality of the eye, such as drainage canals that don’t form properly when a baby is growing in the womb. This can be noticed at birth or later in childhood.

How is glaucoma diagnosed?

Early diagnosis is key when it comes to managing and preventing glaucoma.

Glaucoma can usually be detected during your normal eye check-ups at the opticians. Often glaucoma can be found before you notice any symptoms.

It’s very important to attend routine eye appointments at an optician at least every two years.These appointments aren’t just there to test your eyesight and check for changes — they also review your general eye health, monitor internal eye pressure, and detect glaucoma or any other complications. If you are at risk of glaucoma, you may be asked to attend tests more frequently.

An optician will carry out a number of tests to check for glaucoma, all of which are quick and painless. These will test your vision and measure the pressure inside your eye (known as your IOP) to check for any abnormalities.

If your optician notices signs of glaucoma , they will refer you to an eye doctor (an ophthalmologist). An ophthalmologist will be able to diagnose you, investigate further and establish a treatment plan for you. This will depend on how far the condition has developed, the level of damage to your eye, and the likely cause of your glaucoma.

Glaucoma treatment

There are a few different types of glaucoma treatment available. These include eye drops, laser treatment or surgery. The right treatment for you will depend on which glaucoma type you have, as well as how severe or far along your glaucoma is.

At The McIndoe Centre, we offer safe and effective treatments for glaucoma patients.

This includes laser treatments (which are extremely safe and non-invasive) and surgical glaucoma treatment.

A few types of surgery can be offered, such as Minimally Invasive Glaucoma Surgery (MIGS). As the name suggests, it is a safe, minimally invasive and effective way of lowering pressure in the eye to treat glaucoma.

If your glaucoma is more advanced, then another surgery such as trabeculectomy may be suggested. Trabeculectomy helps to relieve internal eye pressure by creating a new pathway for fluid to drain from the eye.

Our team is more than happy to answer any questions you may have regarding glaucoma treatments — make an enquiry here to arrange a consultation and chat through safe and effective treatments today. Alternatively, you can call our free Private Patient Advisory Team for more information and professional advice on 01342 488054.


Page last reviewed on 07/12/2021