Giant cell arteritis (GCA), also called temporal arteritis, is an inflammation (swelling) of the arteries, which are the blood vessels that carry blood away from the heart. When arteries swell, it reduces the blood flow through these vessels. Because these blood vessels also help nourish your eyes, reduced blood flow can cause sudden vision loss. This condition is called anterior ischemic optic neuropathy (AION).
Many people have severe headaches, head pain and scalp tenderness, particularly around the temples. GCA can affect your eyesight, causing sudden vision loss or double vision. Other symptoms may include: flu-like symptoms including headache, fatigue, and fever; jaw cramps, especially when chewing; stiffness or pain in the neck, hip or arms; unexplained weight loss. Blindness caused by GCA generally happens first in one eye, but can also happen in the other eye if the condition is not treated. That is why it is extremely important to be checked by an eye doctor right away if you have these symptoms.
GCA affects mostly older people. It is rarely found in anyone younger than 50 years old and is more common around age 70. Women are twice as likely as men to have GCA.
Your eye doctor will give you a dilated eye examination to look for signs of damage to the optic nerve. You may also have a visual field test to see if you have lost any peripheral (side) vision. Your doctor will order blood tests. While the tests cannot confirm if you have giant cell arteritis (GCA), they can show whether your body has inflammation (swelling). If the blood tests are normal, you probably do not have GCA. If the blood tests are abnormal, you will need a biopsy (sample of tissue) taken from your temple artery to confirm the findings of the blood tests. Your doctor may also order imaging tests, such as an MRI, to check the health of your arteries.
If there is inflammation in the temporal artery, you will need steroid treatment. It is important to treat GCA as soon as possible to prevent further vision loss. Many people feel better soon after starting treatment, but the treatment can last as long as two years.
If you have lost vision from GCA, your vision will likely stabilize once you start the steroids. However, any vision loss you already have may be permanent. In such cases, learning to make the most of your remaining vision will help you keep your independence.