Melanoma Inside the Eye (Intraocular Melanoma)

What is an intraocular melanoma?

Intraocular melanoma is a type of cancerous tumor in the eye. The part of the eye affected by this rare type of cancer is the uvea. The uvea is made up of:

• the iris (the colored part of the front of the eye that surrounds the pupil)
• the ciliary body (a muscle that helps the eye focus and makes the fluid that fills the front of the eye)
• the choroid (a layer of tissue in the back of the eye).

The location of the melanoma in the uvea affects its symptoms and treatment.

How does it occur?

An ocular melanoma occurs when cells that produce pigment grow uncontrollably. Pigment produces the coloring of the skin and iris of the eye. People with light-colored skin and eyes may have a higher chance of developing melanoma than people with darker skin. What causes the abnormal growth of cells is not known.

Rarely, this type of cancer starts in another part of the body and spreads to the eye.

What are the symptoms?

Often melanomas cause no symptoms. Sometimes they may cause painful, red eyes or changes in your vision.

A melanoma of the iris may look like a dark spot on the iris. It may block part of your vision. A melanoma on the ciliary body or the choroid may cause blurred vision in one eye or may cause part of your side vision to be missing.

How is it diagnosed?

The tumor is usually discovered during a routine exam before you start having symptoms. Your doctor can see a melanoma on the iris with a lighted tool called a slit lamp. Your doctor can see a melanoma inside your eye after dilating (enlarging) your pupil with eyedrops.

If your doctor sees a tumor, you may have an ultrasound (sound wave) scan to see what kind of tumor it is.

How is it treated?

Melanoma inside the eye is a serious and sometimes fatal disease because it can spread to other parts of your body. The main goal of treatment is to limit the growth and spread of the disease. Often melanomas in the eye are treated by doctors who are specialists in the treatment of tumors inside the eye.

If the tumor is small, causes no problems, and is not growing, your eye doctor may not recommend any treatment. He or she will take photographs regularly of the tumor to see if it is changing.

When treatment is given, common types of treatment are:

• Surgery to remove the tumor and affected parts of the eye. Sometimes the whole eye must be removed (enucleation).
• Internal radiation therapy. Small implants of material containing radiation (radioisotopes) are placed next to the eye. The implants, called plaques, deliver radiation to kill cancer cells and shrink the tumor.
  • External beam irradiation therapy. In this procedure, a machine delivers precise beams of X-rays or other high-energy rays to kill cancer cells and shrink tumors.
  • Laser therapy, which uses a very powerful beam of light to destroy the tumor or blood vessels that feed the tumor.

Blood tests and imaging studies such as X-rays, CT scans (computed tomography), or MRI (magnetic resonance imaging) may need to be done to see if the cancer has spread.

How long will the effects last?

The chance of recovery (prognosis) depends on the size and cell type of the cancer, where the cancer is in the eye, and whether the cancer has spread. If not treated, the cancer may spread to other parts of the body and cause death. Although saving your vision is a goal, it is often not possible to treat the tumor without some vision loss. Vision loss from tumor treatment is permanent and may worsen over years, especially with radiation treatment.

You will need to see your eye doctor regularly for the rest of your life even after a successful treatment because there is a chance the tumor could return.

How can it be prevented?

There is no known way to prevent intraocular melanomas.