Inflammation of the optic
nerve (the nerve that carries messages from the back of the eye to the brain). It may be caused by
infection, drugs, toxins, and diseases of the
immune system, such as
multiple sclerosis. Symptoms include sudden changes in vision in one eye, including loss of vision and pain with eye movement. The symptoms often disappear within a few weeks.
immune system (ih-MYOON SIS-tem)
The complex group of organs and cells that defends the body against infections and other diseases.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)infection (in-FEK-shun)
Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)inflammation (IN-fluh-MAY-shun)
Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)multiple sclerosis (MUL-tih-pul skleh-ROH-sis)
A disorder of the central nervous system marked by weakness, numbness, a loss of muscle coordination, and problems with vision, speech, and bladder control. Multiple sclerosis is thought to be an autoimmune disease in which the body's immune system destroys myelin. Myelin is a substance that contains both protein and fat (lipid), serving as a nerve insulator and helping in the transmission of nerve signals.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)nerve (nerv)
A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)
