Maureen was diagnosed with glaucoma in 2008 while in her 60s, following an appointment with her optician. Read her full story. She said:

“It was a shock to be diagnosed with glaucoma but I have adjusted and learned to manage my condition. I support Fight for Sight because they focus on the people who count by researching solutions into conditions like glaucoma.”

Find out how the glaucoma research we fund will have a huge impact for people like Maureen who are living with the condition.

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What is glaucoma?

Glaucoma is the leading cause of irreversible blindness and is characterised by damage to the optic nerve – the nerve that connects the eyes to the brain. Glaucoma, which is actually a small group of similar sight loss conditions, has two major risk factors- elevated eye pressure, and older age.

Around 80 million people across the globe have glaucoma, and with the ageing population, this number is projected to increase to 120 million by 2040.

While glaucoma can be managed if successfully diagnosed, the damage to the optic nerve is irreversible and a cure has yet to be found. 

It is important that we fund research in glaucoma that focuses on both early diagnoses and breakthrough treatments that stand to benefit a large number of patients and create a future everyone can see.

What are the different types of glaucoma?

These are the five main types of glaucoma:

Primary open angle glaucoma (POAG)

Primary open angle glaucoma (POAG) is the most common form. The “angle” is where the eye fluid drains out of, and within this angle is a sponge-like tissue called the trabecular meshwork. Since the angle is open, fluid should drain through but doesn’t due to problems with this sponge-like tissue such as the gaps getting narrower or deposits blocking them. It’s also the type most associated with older age and is also slightly more common in people of African-Caribbean descent.

Acute angle closure glaucoma

Acute angle closure glaucoma, also known as closed angle glaucoma, happens when eye pressure can rise very suddenly potentially leading to acute damage to the optic nerve. As the name suggests, the problem is that the angle where the fluid drains through is simply closed. It’s a lot less common than primary open angle glaucoma and tends to affect people of East Asian origin more. Women are also more likely to have the condition, which is also called acute angle-closure glaucoma or closed-angle glaucoma.

Secondary glaucoma

Secondary glaucoma occurs due to something else going on in the body or eyes, such as a side-effect from certain medications, another underlying eye condition like uveitis (inflammation of the eye), or an eye injury. This differs from primary glaucoma, where there’s no identifiable cause for the glaucoma to develop. Even though the cause of primary and secondary glaucomas may be different, the increase in eye pressure and damage to the optic nerve are the same. Unlike primary open angle glaucoma, when the underlying problem causing the raised pressure is cured or corrected, the pressure may return to normal - if the increased eye has already caused damage to the optic nerve however, any resulting sight loss is permanent and irreversible.

Normal tension glaucoma (NTG)

Normal tension glaucoma is diagnosed despite eye pressure being normal. Why it happens isn’t entirely clear but it’s believed some people’s optic nerves may be more fragile, meaning that even a normal level of eye pressure is still too high and causes damage. Because the pressure is at a normal level, it can be harder to pick up on during routine eye checks than other types of glaucoma. Like POAG, there are typically no symptoms in NTG until the very advanced stages, but the condition can often affect the central vision earlier than other types of glaucoma.

Congenital glaucoma

Congenital glaucoma, also known as childhood glaucoma, is when the condition is present from birth due to an abnormality within the eye. This is a rare type of glaucoma which affects about one in every 10,000 infants. Symptoms include enlarged eyes, cloudiness of the cornea, and photosensitivity (sensitivity to light).

What causes glaucoma?

Glaucoma is often (but not always) linked to high eye pressure. Our eyes contain fluid called aqueous humour, which helps to nourish and provide energy to the eye. In fact, it plays a similar role to blood (but is colourless so everything we see isn’t red) and has to constantly circulate. Similar to how people can have high blood pressure, so too can you have high eye pressure. 

Why some people develop glaucoma and others don’t is not fully understood yet, but a number of causes have been recognised. Age is the biggest risk factor with almost 10% of people aged 75 and over affected by glaucoma. People with a close relative, such as a parent, with the condition may also be at higher risk, and ethnicity (African, Caribbean, Asian origin) is a factor for certain types of glaucoma too.

What are the signs and symptoms of glaucoma?

Glaucoma tends to develop slowly and often doesn’t cause noticeable symptoms until damage has already occurred. Sometimes people experience acute glaucoma which causes a sudden onset of severe eye pain and blurred vision.

When glaucoma does cause symptoms, these might include: 

  • Blurred and reduced vision starting with peripheral vision (outer edges) and develops very slowly. 
  • Seeing rings and rainbow-coloured circles around bright lights. 
  • Severe eye pain that comes on suddenly. This might be accompanied by redness and tenderness of the eye and surrounding area, plus a headache, nausea and vomiting. 

How is glaucoma diagnosed? 

Glaucoma is usually diagnosed following routine eye tests. Tests for glaucoma often start with an eye pressure test. An optometrist will also examine the front part of the eye, to see whether they can spot any issues with fluid drainage, such as a blockage.

Visual field tests are also carried out to see whether there’s any loss of peripheral vision, and the optic nerve will be assessed too. This sometimes involves eye drops or a scan of the eye so the optometrist can get a closer look at the eye.

If glaucoma is suspected, patients will be referred to a specialist to confirm the diagnosis and assess any damage that’s already occurred. 

What treatments are there for glaucoma? 

Glaucoma is treated by managing the underlying causes to prevent further damage to the optic nerve. Each person’s treatment plan will depend on many factors including general health and medical history. Treatment can't reverse sight loss that has already occurred, but it can help stop this from getting any worse.

The main treatment options currently available are:

Eye Drops Treatment

Eye drops that reduce the amount of fluid being produced in the eye or by improving fluid drainage, which will reduce eye pressure. There are several different types that can be used, and are normally used between one and four times a day. People with glaucoma may need to try several types before finding one that works best for them - or may need to use more than one type at a time. Eye drops can cause unpleasant side effects, such as eye irritation, and some aren't suitable for people with certain underlying conditions.

Laser treatment

A fairly common procedure to help improve fluid drainage and lower eye pressure, completed under local anaesthetic as an outpatient. Laser treatment may be recommended if eye drops don't improve your symptoms. Laser treatment is usually carried out while the patient is awake, with local anaesthetic drops applied to numb the eyes. Patients may feel a brief twinge of pain or heat during the procedure.


A surgical procedure that is only required in a small number of cases, where treatment with eyedrops or laser haven't been effective. A specialist surgeon will create a new drainage channel within the eye to improve fluid drainage. Most people won't need to take eye drops any more after a trabeculectomy, and you shouldn't be in a lot of pain after surgery. However, the affected eye might water and be red after surgery, and vision may be slightly blurred for up to 6 weeks - this should return to normal.

How can glaucoma be prevented?

There is no known way to stop glaucoma from developing, but there are some known ways to stop severe sight loss from glaucoma, like closely monitoring steroid medication which can raise eye pressure, eating well, and exercising.

Fight for Sight is currently funding a research project at UCL Institute of Ophthalmology investigating the effect of lifestyle factors – such as alcohol, smoking, exercise and diet – on the development of glaucoma.

What research is underway? 

Sight loss from glaucoma is irreversible. Fight for Sight is dedicated to funding pioneering research to improve our understanding and prevent glaucoma. The charity also aims to improve early diagnosis and find new treatments.

Fight for Sight is funding 27 glaucoma research projects across the UK. For example, researchers are finding treatments for glaucoma that will lower eye pressure and reduce damage to the parts of the eye that are responsible for vision. The research we fund will have a huge impact on those living with the condition.

Read more on our glaucoma research

Professor Keith Martin is leading a project, based at the University of Cambridge, which aims to strengthen the connection between the eye and the brain, protecting and regrowing the vital cells that are damaged by glaucoma and other conditions. Listen to Keith's podcast to find out more about his research into glaucoma. 

James Morgan, Professor of Ophthalmology at Cardiff University, is studying the extent to which the immune system can accelerate the damage to retinal cells that connect the eye to the brain. Watch James's video below to find out more about his research. 

What can I do?

Have your eyes tested every two years even if you think your vision is fine. An eye test can spot glaucoma and, if caught early, treatment may prevent further deterioration. If you have been advised that you are at risk of glaucoma (e.g. a close relative has the condition) you are entitled to more frequent free eye tests.

Find your nearest optician

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Last updated August 2022
Approved by Dr Ben Mead, University of Cardiff

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