Intraocular melanoma is a disease in which malignant (cancer) cells form in the tissues of the eye.

Intraocular melanoma begins in the middle of 3 layers of the wall of the eye. The outer layer includes the white sclera (the "white of the eye") and the clear cornea at the front of the eye. The inner layer has a lining of nerve tissue, called the retina, which senses light and sends images along the optic nerve to the brain.

The middle layer, where intraocular melanoma forms, is called the uvea or uveal tract, and has 3 main parts:

Iris
The iris is the colored area at the front of the eye (the "eye color"). It can be seen through the clear cornea. The pupil is in the center of the iris and it changes size to let more or less light into the eye.
 
 
Ciliary body
The ciliary body is a ring of tissue with muscle fibers that change the size of the pupil and the shape of the lens. It is found behind the iris. Changes in the shape of the lens help the eye focus. The ciliary body also makes the clear fluid that fills the space between the cornea and the iris.
 
Choroid
The choroid is the layer of blood vessels that bring oxygen and nutrients to the eye. Most intraocular melanomas begin in the choroid.

Intraocular melanoma is a rare cancer, but it is the most common eye cancer in adults.

Age and sun exposure may increase the risk of developing intraocular melanoma.

Anything that increases your risk of getting a disease is called a risk factor. Risk factors for intraocular melanoma include the following:

  • Older age.
  • Having a fair complexion (blond or red hair, fair skin, green or blue eyes).
  • Being exposed to a lot of sunlight or to certain chemicals.

Warning Signs

Possible signs of intraocular melanoma include a dark spot on the iris or blurred vision.

Intraocular melanoma may not cause any early symptoms. It is sometimes found during a routine eye exam when the doctor dilates the pupil and looks into the eye. The following symptoms may be caused by intraocular melanoma or by other conditions. A doctor should be consulted if any of these problems occur:

  • A dark spot on the iris.
  • Blurred vision.
  • A change in the shape of the pupil.
  • A change in vision.

Glaucoma may develop if the tumor causes the retina to separate from the eye. If this happens, there may be no symptoms, or symptoms may include the following:

  • Eye pain.
  • Blurred vision.
  • Eye redness.
  • Nausea.

Tests that examine the eye are used to help detect (find) and diagnose intraocular melanoma.

The following tests and procedures may be used:

  • Eye exam with dilated pupil: An examination of the eye in which the pupil is dilated (enlarged) with medicated eyedrops to allow the doctor to look through the lens and pupil to the retina. The inside of the eye, including the retina and the optic nerve, is examined using an instrument that produces a narrow beam of light. This is sometimes called a slit-lamp exam. The doctor may take pictures over time to keep track of changes in the size of the tumor and how fast it is growing.
  • Indirect ophthalmoscopy: An examination of the inside of the back of the eye using a small magnifying lens and a light.
  • Ultrasound exam of the eye: A procedure in which high-energy sound waves (ultrasound) are bounced off the internal tissues of the eye to make echoes. Eye drops are used to numb the eye and a small probe that sends and receives sound waves is placed gently on the surface of the eye. The echoes make a picture of the inside of the eye. The picture, called a sonogram, shows on the screen of the ultrasound monitor.
  • Transillumination of the globe and iris: An examination of the iris, cornea, lens, and ciliary body with a light placed on either the upper or lower lid.
  • Fluorescein angiography: A procedure to look at blood vessels and the flow of blood inside the eye. An orange fluorescent dye (fluorescein) is injected into a blood vessel in the arm. As the dye travels through blood vessels of the eye, a special camera takes pictures of the retina and choroid to detect any blockage or leakage.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

  • The type of melanoma cells (how they look under a microscope).
  • The size of the tumor.
  • Which part of the eye the tumor is in (the iris, ciliary body, or choroid).
  • Whether the tumor has spread within the eye or to other places in the body.
  • The patient's age and general health.
  • Whether the tumor has recurred (come back) after treatment.

In patients with small tumors that have not spread, intraocular melanoma can be cured and vision can usually be saved.

Stages of Intraocular (Eye) Melanoma

After intraocular melanoma has been diagnosed, tests are done to find out if cancer cells have spread within the eye or to other parts of the body.

The process used to find out if cancer has spread within the eye or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests and procedures may be used in the staging process:

  • Gonioscopy: An examination of the front part of the eye between the cornea and iris. A special instrument is used to check for blockages in the area where fluid drains out of the eye.
  • Ultrasound biomicroscopy: A procedure that uses high-energy sound waves to measure small tumors. The amount of detail is about the same as that of a low-power microscope. Tumors can be examined this way for shape, thickness, and signs that they have spread to nearby tissue.
  • Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
  • Liver function tests: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by the liver. A higher than normal amount of a substance can be a sign the cancer has spread to the liver.
  • Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs, such as the liver, and make echoes. The echoes form a picture of body tissues called a sonogram.
  • Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the liver or brain, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

Sometimes pictures of the tumor are taken over a period of time and compared to see if the tumor has grown.

The following sizes are used to describe intraocular melanoma:

Small

The tumor is at least 5 millimeters in diameter and from 1 to 3 millimeters thick.

Medium

The tumor is less than 16 millimeters in diameter and from 2 to 10 millimeters thick.

Large

The tumor is at least 16 millimeters in diameter or more than 10 millimeters thick.

Diffuse

The tumor is flat and grows widely across the uvea.

Intraocular melanoma may spread to nearby tissues or to other parts of the body.

If intraocular melanoma spreads to the optic nerve or nearby tissue of the eye socket, it is called extraocular extension. Intraocular melanoma may also be metastatic and spread to the liver, lung, or bone, or to areas under the skin.

Treatment Option Overview

There are different types of treatments for patients with intraocular melanoma.

Different types of treatments are available for patients with intraocular melanoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

Five types of standard treatment are used:

Surgery

Surgery is the most common treatment for intraocular melanoma. The following types of surgery may be used:

  • Local tumor resection: Surgery to remove the tumor and a small amount of healthy tissue around it.
  • Enucleation: Surgery to remove the eye and part of the optic nerve. This is done if the tumor is large and vision cannot be saved. The patient may be fitted for an artificial eye after enucleation.
  • Exenteration: Surgery to remove the eye and eyelid, and muscles, nerves, and fat in the eye socket. The patient may be fitted for an artificial eye or facial prosthesis after exenteration.

Watchful Waiting

Watchful waiting is closely monitoring a patient’s condition without giving any treatment until symptoms appear or change. A series of pictures is taken over time to keep track of changes in the size of the tumor and how fast it is growing.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Localized plaque radiation therapy is a type of internal radiation therapy that may be used for tumors of the eye. Radioactive seeds are attached to a disk, called a plaque, and placed directly on the wall of the eye where the tumor is located. The side with the seeds faces the eyeball and delivers radiation to the eye. The plaque, which is often made of gold, helps protect nearby tissues from radiation damage.

Charged-particle radiation therapy is a type of external radiation therapy. A special radiation therapy machine aims tiny, invisible particles, called protons or helium ions, at the cancer cells to kill them with little damage to nearby normal tissues. Charged-particle radiation therapy uses a different type of radiation than the x-ray type of radiation therapy.

Gamma Knife radiosurgery may be used for some melanomas. This non-surgical treatment aims tightly focused gamma rays directly at the tumor so there is little damage to healthy tissue. Gamma Knife is a type of stereotactic radiosurgery.

Photocoagulation

Photocoagulation is a procedure that uses laser light to destroy blood vessels that supply nutrients to the tumor, causing the tumor cells to die. Photocoagulation may be used to treat small tumors. This is also called light coagulation.

Thermotherapy

Thermotherapy is the use of heat to destroy cancer cells. Thermotherapy may be given using:

  • A laser beam aimed through the dilated pupil or onto the outside of the eyeball.
  • Ultrasound.
  • Microwaves.
  • Infrared radiation (light that cannot be seen but can be felt as heat).

Treatment Options for Intraocular (Eye) Melanoma

Iris Melanoma

Treatment of iris melanoma may include the following:

  • Watchful waiting.
  • Surgery (local tumor resection or enucleation).
  • Plaque radiation therapy.

Ciliary Body Melanoma

Treatment of tumors in the ciliary body and choroid may include the following:

  • Plaque radiation therapy.
  • Charged-particle external radiation therapy.
  • Surgery (local tumor resection or enucleation).

Small Choroid Melanoma

Treatment of small choroid melanoma may include the following:

  • Watchful waiting.
  • Plaque radiation therapy.
  • Charged-particle external radiation therapy.
  • Gamma Knife radiation surgery.
  • Photocoagulation.
  • Thermotherapy.
  • Surgery (local tumor resection or enucleation).

Medium and Large Choroid Melanoma

Treatment of medium choroid melanoma may include the following:

  • Plaque radiation therapy.
  • Plaque radiation therapy with photocoagulation or thermotherapy.
  • Charged-particle external radiation therapy.
  • Surgery (local tumor resection or enucleation).

Treatment of large choroid melanoma may include surgery (enucleation) with or without radiation therapy before surgery.

Extraocular Extension Melanoma and Metastatic Intraocular (Eye) Melanoma

Treatment of extraocular extension melanoma or metastatic melanoma may include surgery (exenteration) with or without radiation therapy.

Recurrent Intraocular (Eye) Melanoma

Recurrent intraocular melanoma is cancer that has recurred (come back) after it has been treated. The melanoma may come back in the eye, or in other parts of the body.

Treatment of recurrent intraocular melanoma is usually within a clinical trial.

 

Source:  National Cancer Institute