Overview

Eye cancer is a general term used to describe many types of tumors that occur in various parts of the eye. It occurs when cells in or around the eye grow abnormally and form a tumor. A tumor may be benign (noncancerous) or malignant (cancerous, meaning cells can spread to other parts of the body). Cancer that forms in the eyeball is called an intraocular malignancy.

Parts of the eye

The eye is the organ that collects light and sends messages to the brain to form a picture. The three main parts of the eye are:

• Eyeball
  
  
• Orbit (eye socket)
  
  
• Adnexal (accessory) structures (such as the eyelid and tear glands)

The outer part of the eye is made up of the sclera, retina, and uvea. The sclera is the outer wall of the eyeball. The retina is a thin-layered structure that lines the eyeball and sends information from the eye to the brain. The uvea nourishes the eye. Both the retina and the uvea contain blood vessels. The uvea consists of the following:

• Iris: The colored part of the eye that controls the amount of light entering the eye
  
  
• Ciliary body: Muscular tissue that produces the watery fluid (aqueous humor) in the eye and helps the eye focus
  
  
• Choroid: The layer of tissue underneath the retina that contains connective tissue and melanocytes and nourishes the inside of the eye; the choroid is the most common site for a tumor.

Types of intraocular cancer

The most common intraocular cancer in adults is uveal metastases, which is cancer that has spread to uvea from another place in the body, called secondary cancer. This article is about primary intraocular cancer, meaning that the tumor started in the eye, not somewhere else in the body.

Melanoma is the most common type of primary intraocular cancer in adults. It begins when pigmented (colored) cells in the eye called melanocytes grow uncontrollably. Intraocular melanoma is also called uveal melanoma.

Medical doctors who specialize in the diseases and function of the eye are called ophthalmologists (or “eye MDs”). These doctors can diagnose and treat intraocular melanoma. Optometrists are another type of eye doctor. They prescribe eyeglasses and contact lenses. They are not medical doctors and are not trained to treat intraocular cancer.

Other, less common types of an intraocular tumor include:

Intraocular lymphoma is lymphoma that begins in the eyeball. This condition is rare and can be difficult for doctors to diagnose. Many doctors consider intraocular lymphoma to be a type of central nervous system lymphoma. Most intraocular lymphomas are non-Hodgkin lymphoma. Refer to the Cancer.Net Guide to Non-Hodgkin Lymphoma for more information.

Retinoblastoma is a rare form of childhood eye cancer. Information about this cancer can be found in the Cancer.Net Guide to Retinoblastoma, Childhood Cancer.

Hemangioma is a benign vascular tumor of the choroid and retina.

In addition, rare tumors of the eye include:

Conjunctival melanoma, a tumor of the conjunctiva (a membrane that lines the eyelid and eyeball). If this tumor is not treated, it can spread to the lymph nodes. This tumor tends to recur (come back after treatment) on the eye’s surface and looks like dark spots on the eye. Doctors often perform a biopsy (removal of a sample of the tissue for examination under a microscope) on a lesion that appears to be conjunctival melanoma.

Eyelid carcinoma (basal or squamous cell) is a variation of skin cancer. This tumor may be surgically removed and is usually not dangerous if it is treated early. Refer to the Cancer.Net Guide to Eyelid Cancer for more information.

Statistics

In 2009, an estimated 2,350 adults (1,200 men and 1,150 women) in the United States will be diagnosed with primary intraocular cancer. It is estimated that 230 deaths (120 men and 110 women) from this disease will occur this year.

Most new cases (between 1,300 and 1,800) of primary intraocular cancer this year will be melanomas. While the number of new cases and deaths from skin melanoma has been increasing over the past 30 years, the number of new intraocular melanoma cases has remained constant or even slightly decreased during this time. Cancer that has spread to the eye from another place in the body (secondary eye cancer) is more common than primary eye cancer.

The five-year relative survival rate (the percentage of people who survive at least five years after the cancer is detected, excluding those who die from other disease) depends on the size and location of the tumor.

Iris melanoma is rare and does not usually spread. The five-year relative survival rate for people with iris melanoma is about 95%.

Choroidal melanoma is the most common type of intraocular melanoma.

• The five-year relative survival rate for people with small choroidal melanoma is approximately 85%.
  
  
• The five-year relative survival rate for people with medium choroidal melanoma is approximately 68%.
  
  
• The five-year relative survival rate for people with large choroidal melanoma is approximately 50% to 60%.

Ciliary body melanoma is rare. Five-year relative survival rates are hard to determine for this type of melanoma, although it generally has a poorer prognosis (chance of recovery) than choroidal melanoma because it is typically diagnosed at a more advanced stage.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with eye cancer. Because the survival statistics are measured in five-year (or sometimes one-year) intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Statistics adapted from the American Cancer Society's publication, Cancer Facts & Figures 2009, and the National Cancer Institute.

Find out more about basic cancer terms used in this section.