Giant cell arteritis (GCA), also known as temporal arteritis, is a condition that can be a great threat to your sight.
It affects large and medium sized arteries in your body; in particular, the arteries in your neck and head. GCA is sometimes referred to as temporal arteritis, as one of the more commonly affected arteries is the temporal artery at the side of your forehead (temple).
In GCA, the artery walls become inflamed (arteritis) with large inflammatory cells (giant cells). The inflammation causes the affected arteries to become swollen, greatly restricting the blood flow through them. This reduction in blood supply is known as ischaemia. If the blood flow becomes too restricted, the structures supplied by these arteries will be affected. If the artery which supplies the eye is affected, then this can cause permanent sight loss in that eye.
Our downloadable factsheet has more information about GCA:
Below is a summary of information from our guide.
The cause of GCA is unknown. It is not a common condition and it rarely affects people under the age of 50. It can affect people from 60 years of age, but more usually, a person will be in their 70s when they experience GCA. Women are more commonly affected by GCA than men.
One of the first signs of GCA is a severe headache which may come on suddenly or gradually. It is often at the side of your forehead, at your temples, and it may affect one or both sides of your head. The headache associated with GCA will probably not feel like any headache you’ve had before.
You may also feel that your temples and scalp are tender to touch, so that combing or brushing your hair feels uncomfortable.
Some people with GCA also experience pain around their eyes within the eye sockets.
Another early sign of GCA is pain on chewing. This can be a cramp-like pain in your jaw which can make you stop eating. You may hear this referred to as jaw claudication and it is due to ischaemia in the muscles that help you to chew. Ischaemia can also cause pain in your tongue or mouth.
Some people with GCA also experience weight loss, tiredness, night sweats, fever and depression.
If you have any of the symptoms outlined above, you should contact your GP urgently.
You may experience a temporary loss of vision in one eye which returns after a while. This is called amaurosis fugax and it is a sign of ischaemia (lack of blood flow). You may also experience double vision that you haven’t had before because the muscles controlling your eye movements are affected.
About 30-50 per cent of people who have untreated GCA will develop a permanent and severe loss of vision in one eye. Without immediate treatment, about a third of these people will develop sight loss in the other eye, often within a week of the first eye. Therefore, it is vital that you see an ophthalmologist (hospital eye doctor) immediately in A&E if you experience sudden sight loss in one eye. Sudden loss of vision should always be investigated immediately by an ophthalmologist, even if your sight returns after a while, and even if you are not experiencing any of the other symptoms of GCA.
Some people lose their sight without having previously noticed any other symptom of GCA. If you experience sudden sight loss, you should go to A&E or to a hospital eye casualty department straight away to be seen urgently so that if treatment is needed, it can be given as soon as possible.
If it is suspected that you have GCA, you will be given treatment straight away, even before all the results of the diagnostic tests are obtained. This is because it is important to try and reduce any possible inflammation as quickly as possible, and to prevent blood flow in other arteries becoming restricted.
There are several things that your ophthalmologist or GP will check:
If it is suspected that you have GCA, emergency treatment will be started immediately with a high dose of steroids.
Steroids are drugs that reduce inflammation in the body and, if GCA is suspected, you will be given steroid tablets to take even if your test results have not come through yet. The aim of this emergency treatment is to prevent sight loss and other general health concerns such as stroke and heart attack.
You will probably have to take steroid tablets for between one and two years or even longer, with the dose being reduced gradually over time as the inflammation subsides.
A treatment involving biological therapy has recently been approved for treating GCA. Biological therapy treatments involve the use of drugs that alter a biological process occurring in your body.
With GCA, a number of proteins are produced by the body. One particular protein has been found to be very high in people who have GCA. Biological therapy treatment blocks the action of this protein so that the inflammation is reduced.
It is given as a weekly injection into the skin and you may need to have these injections for up to a year, but your specialist will advise you about this. These injections can be given in addition to your steroid tablets or on their own when steroids have been stopped. Steroids can lead to several unwanted side effects when taken at a high dose for a long time. By adding biological therapy to your treatment, lower doses of steroids can be given while still controlling your GCA.
If it is suspected that your sight loss is due to GCA, you may be admitted to hospital for treatment or given treatment to use at home straight away.
If you are admitted, you may be given a high dose of steroids directly into your bloodstream via a drip over the next few days. If you are not admitted, you’ll be given high dose steroid tablets to use at home and then followed up by the hospital. The high dose steroids are given to try and bring down the swelling in your arteries as quickly as possible. Unfortunately, there is no treatment available that can bring back the sight loss caused by GCA so it is unlikely that the vision you have lost will return. The aim of this treatment is to prevent further sight loss in your other eye.
About half the people with GCA have another condition called polymyalgia rheumatica (PMR) where the blood vessels supplying some of the larger muscles in your body are inflamed. The muscles particularly affected by PMR are those in your shoulders, neck, hips and back. These muscles can be painful and stiff, particularly on waking. It is possible to have GCA without having PMR as well. It is thought they might be different conditions with the same underlying cause and they are both treated with steroids.
To read our full information on giant cell arteritis, download our factsheet from the top of the page (the first link after the title of this page).