Eye melanoma

Eye melanoma

Definition:

Melanoma is a type of cancer that develops in the cells that produce melanin — the pigment that gives your skin its color. Your eyes also have melanin-producing cells and can develop melanoma. Eye melanoma is also called ocular melanoma.

Most eye melanomas form in the part of the eye you can't see when looking in a mirror. This makes eye melanoma difficult to detect. In addition, eye melanoma typically doesn't cause early signs or symptoms.

Treatment is available for eye melanomas. Treatments for some small eye melanomas may not interfere with your vision. However, treatment for large eye melanomas typically causes some vision loss.

Symptoms:

Eye melanoma may not cause signs and symptoms. When they do occur, signs and symptoms of eye melanoma can include:

• A growing dark spot on the iris
• A sensation of flashing lights
• A change in the shape of the dark circle (pupil) at the center of your eye
• Poor or blurry vision in one eye
• Loss of peripheral vision
• Sensation of flashes and specs of dust in your vision (floaters)

When to see a doctor
Make an appointment with your doctor if you have any signs or symptoms that worry you. Sudden changes in your vision signal an emergency, so seek immediate care in those situations.


Causes:

It's not clear what causes eye melanoma, also called ocular melanoma. Doctors know that eye melanoma occurs when errors develop in the DNA of healthy eye cells. The DNA errors tell the cells to grow and multiply out of control, so the mutated cells go on living when they would normally die. The mutated cells accumulate in the eye and form an eye melanoma.

Where eye melanoma occurs
Eye melanoma most commonly develops in the cells of the uvea, the vascular layer of your eye sandwiched between the retina, the thin layer of tissue that lines the back inner wall of your eyeball, and the white of your eye (sclera). Eye melanoma can occur in the front part of the uvea (iris and ciliary body) or in the back part of the uvea (choroid layer).

Eye melanoma can also occur on the most outer layer on the front of the eye (conjunctiva), in the socket that surrounds the eyeball and on the eyelid, though these types of eye melanoma are very rare.


Complications:

Complications of eye melanoma may include:

• Increasing pressure within the eye (glaucoma). A growing eye melanoma may cause glaucoma. Signs and symptoms of glaucoma may include eye pain and redness, as well as blurry vision.
  
• Vision loss. Large eye melanomas often cause vision loss in the affected eye and can cause complications, such as retinal detachment, that also cause vision loss. Small eye melanomas can cause some vision loss if they occur in critical parts of the eye. You may have difficulty seeing in the center of your vision or on the side. Very advanced eye melanomas can cause complete vision loss.
  
• Eye melanoma that spreads beyond the eye. Eye melanoma can spread outside of the eye and to distant areas of the body, including the liver, lungs and bones. 

Treatments and drugs:

Your eye melanoma treatment options will depend on the location and size of the eye melanoma, as well as your overall health and your preferences.

Waiting to treat small eye melanomas
A small eye melanoma may not require immediate treatment. If the melanoma is small and isn't growing, you and your doctor may choose to wait and watch for signs of growth. If the melanoma grows or causes complications, you may choose to undergo treatment at that time.

Surgery
Operations used to treat eye melanoma include procedures to remove part of the eye or a procedure to remove the entire eye. Options may include:

• Surgery to remove the melanoma and a small area of healthy tissue. Surgery to remove the melanoma and a band of healthy tissue that surrounds it may be an option for treating small melanomas. What procedure you'll undergo depends on the size and location of your eye melanoma. For instance, surgery to remove a small melanoma affecting the iris is called iridectomy. Surgery to remove a melanoma in the choroid is called choroidectomy.
  
• Surgery to remove the entire eye (enucleation). Enucleation is often used for large eye tumors. It may also be used if the tumor is causing eye pain. After the eye with melanoma is removed, an implant is inserted into the same position, and the muscles controlling movement of the eye are attached to the implant, which allows the implant to move. After you've had some time to heal, an artificial eye (prosthesis) is made. The front surface of your new eye will be custom painted to match your existing eye.

Radiation therapy
Radiation therapy uses high-powered energy beams, such as protons or gamma rays, to kill cancer cells. Radiation therapy is typically used for small to medium-sized eye melanomas.

The radiation is usually delivered to the tumor by placing a radioactive plaque on your eye, directly over the tumor in a procedure called brachytherapy. The plaque is held in place with temporary stitches. The plaque looks similar to a bottle cap and contains several radioactive seeds. The plaque remains in place for four to five days before it's removed.

The radiation can also come from a machine that directs radiation, such as proton beams, to your eye (external beam radiation or teletherapy). This type of radiation therapy is often administered over several days.

Laser treatment
Treatment that uses a laser to kill the melanoma cells may be an option in certain situations. One type of laser treatment, called thermotherapy, uses an infrared laser and is sometimes used in combination with radiation therapy.

Cold treatments
Extreme cold (cryotherapy) may be used to destroy melanoma cells in some small eye melanomas, but this treatment isn't commonly used.