What is it?

Glaucoma is the name for a group of eye conditions that cause sight loss because of damage to the optic nerve. This is the specialised nerve that carries signals from the eye to brain. Glaucoma is the second most common cause of blindness in the world after cataract. The number of people affected by glaucoma is continuing to rise as life expectancy increases.

Sight lost to glaucoma cannot be recovered. However, early diagnosis, monitoring and regular treatment can help prevent further vision loss. Regular eye tests can help to spot glaucoma early.

  • Causes

    Glaucoma is often (but not always) linked to high pressure in the eye. Eyes hold their shape by producing fluid (aqueous humour) which fills the middle part of the eye. The pressure in the eye is determined by the balance between this fluid being produced and draining away.

    If the eye can’t drain fluid well enough, pressure inside the eye will rise. This can squeeze and damage the cells that together form the optic nerve (retinal ganglion cells).

    Glaucoma can sometimes develop when eye pressure rises due to another eye condition. This is known as secondary glaucoma. Babies may be born with ‘congenital’ glaucoma, but this is rare.

    Some people with glaucoma have normal or low eye pressure. This can be linked to low blood pressure or other conditions such as sleep apnoea. Women and people with Japanese heritage are more at risk of this type of glaucoma.

    Who is at risk?

    Older age and family history can increase the risk of glaucoma, as faulty genes can be inherited. People of African, Caribbean and Asian origin also have a higher risk.

  • Symptoms

    Sight loss in glaucoma usually happens very slowly, over time. It may be so slow that people don’t notice until the condition is quite severe.

    Primary open angle glaucoma (POAG) is the most common type of glaucoma. Sight loss usually starts around the edge of the field of view and slowly moves inwards. The vision may seem blurred in the areas affected by glaucoma.

    Acute angle closure glaucoma is much rarer in people of European origin. It involves a sudden blockage to fluid outflow and a much quicker build-up of pressure. This can cause great pain. Vision may seem misty and rainbow-coloured rings around white lights might appear.

  • Treatments

    Treatment for primary open angle glaucoma usually starts with eye drops or laser treatment to lower eye pressure. If this doesn’t work, different drops or an operation known as a trabeculectomy may be needed. A trabeculectomy involves removing a small area of eye tissue to help fluid drain from the eye.

    Acute angle closure glaucoma requires immediate hospital treatment to avoid sight loss. Medication, laser treatment or surgery can restore normal pressure.

    Treatments are unable to restore the vision lost by glaucoma but it can stop any further vision loss.

  • Research

    Sight loss in glaucoma is irreversible. This means that research is focused on preventing optic nerve damage with treatment or by spotting the earliest signs. We need to know more about the genes linked to glaucoma, specifically how these genes cause or influence the likelihood of developing glaucoma. We can also improve on current treatments, for example by preventing sight-threatening scars developing following surgery.

    Read our research projects
  • Personal stories

    Maureen was diagnosed with glaucoma in 2008 after an appointment at her local opticians.

    Maureen was getting blurred vision and thought that her glasses prescription had altered, so called into her opticians. They carried out a test revealing that she had glaucoma and was referred to her nearest hospital.

    She said: “When they diagnosed me I just felt terrible because I only knew the word glaucoma but I didn't know what it involved. I didn't know I had lost sight.”

    As well as glaucoma Maureen was also diagnosed with cataracts in both eyes and was told she could go blind.

    Maureen added: “I thought I would go blind almost immediately – I thought it would be within a week. The consultant told me that I needed to attend regularly hospital visits from that point onwards.”

    In January 2010 Maureen had a cataract operation in her right eye and her left eye was operated on a month later. This made a huge impact on her sight – it was a miracle – everything was much clearer than before.

    Maureen had been controlling the glaucoma through prescribed eye drops, after using them for three years, nothing seemed to work to help reduce the pressure at the back of the eye. In 2012, Maureen was offered a procedure, called trabeculectomy. This involved making a hole in both eyes to relieve the pressure and let the fluid drain to help reduce this.

    In terms of Maureen’s vision she still has some loss of sight at the top of her eyes due to the glaucoma. Plus, she experiences some friction when blinking, so uses lubrication and a night-time ointment to keep the discomfort at bay. The condition also prevents Maureen doing hobbies such as; yoga, pilates, swimming.

    Maureen: “I support Fight for Sight because they are a very good charity and they do such good work in bringing notice to the people who count. There’s so many eye diseases that I didn't know about - glaucoma is just one in so many hundred I would think. I think anyone who brings it to the forefront like Fight for Sight is doing a marvellous job and hopefully they will get the research money that they need to do more.”

  • Clinical trials

    You could play an important part in eye research by being a participant in clinical research study that may benefit many people. You could even help shape clinical research by becoming more actively involved and having a say. Patients, carer, or anyone with an interest can help.

    What are clinical trials

    Clinical trials are research studies that find out if a medical strategy, treatment, or device is safe and effective for humans. They are a key research tool for improving medical knowledge and patient care. The people who carry out research are mostly the same doctors and healthcare professionals who treat people. Their aim is to find better ways of treating patients and keeping people healthy.

    Taking part

    Here are some ways to find out about research projects and clinical trials that you can get involved in.

    UK Clinical Trials Gateway

    The UK Clinical Trials Gateway run by the National Institute for Health Research (NIHR) provides easy to understand information about clinical research trials running in the UK, and gives to a large range of information about these trials. It is designed to enable patients and clinicians to locate and contact trials of interest. Visit their website and select the eye condition that you are interested in.

    NIHR Clinical Research Network Portfolio

    The NIHR Clinical Research Network Portfolio is a database of high-quality clinical research studies in England, Northern Ireland, Scotland and Wales. Within this the Ophthalmology Specialty Group supports a national portfolio of research studies in ophthalmology and the vision sciences. See their website for details.

    If you wish to join a trial it is always best to discuss this with your doctor or clinical team first.

Last updated October 2017
Approved by Prof Keith Martin, University of Cambridge

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