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 change and grow uncontrollably, forming a mass called 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.
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.
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:
- 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 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 the uvea from another place in the body; this is 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.
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.
Retinoblastoma is a rare form of childhood eye cancer.
Hemangioma is a benign vascular tumor of the choroid and retina.
Other, rare cancers of the eye include the following:
Conjunctival melanoma is a tumor of the conjunctiva (a membrane that lines the eyelid and eyeball). If it is not treated, it can spread to the lymph nodes (tiny, bean-shaped organs located throughout the body that fight disease). A conjunctival melanoma 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 spot 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.
Lacrimal gland tumor is a benign or malignant tumor of the glands that produce tears.
Find out more about basic cancer terms used in this section.
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