Melanoma is an aggressive form of skin cancer that can be life threatening. Although melanoma typically affects the skin, it can also spread to the eye. This type of cancer may only be in the eye, or it can spread to other parts of the body (usually the liver). Melanoma is the most common type of eye tumor in adults, however, melanoma of the eye alone is rare. People with fair skin or blue eyes are most affected by this type of cancer (UMMC).
Malignant melanoma of the eye is a rare condition that can occur when the eye has been exposed to too much ultraviolet radiation (sunlight). The choroid layer (which is where the blood vessels are stored) of the eye is most commonly affected by malignant melanoma. However, the disease can affect other structures of the eye, including:
- ciliary body: helps lubricate eyes and contains muscles that help eyes focus)
- conjunctiva: a thin, transparent tissue that covers the sclera, or “whites” of the eye)
- iris: the colored part of the eye that helps control how much light is let in
- orbit: the cavity in the skull that contains the eye
Malignant melanoma of the eye develops when pigment cells found in the eye begin to grow uncontrollably. Pigment cells in the eye are responsible for your eye color. In most instances, the cause of uncontrollable cell growth is not known. However, exposure to ultraviolet radiation has been identified as a potential cause for the disease.
Malignant melanoma that begins in the eye is known as a primary tumor. This type of cancer can occur at any age, but is more common in people over the age of 50, and affects men and women equally (American Cancer Society, 2012).
Malignant melanoma may also result if cancer that develops in other parts of the body metastasizes. Metastasis occurs when cancer from one organ or part of the body grows and spreads to another. In the case of malignant melanoma, the condition may result because of a metastasis of liver cancer. This type of cancer is known as a secondary tumor.
Many patients with primary malignant melanoma may have no symptoms. The condition is often found during a routine eye exam. In patients who develop symptoms, the signs of the condition are quite distinct. They include:
- bulging eyes
- changes in the color of the iris
- vision changes
- red, swollen, and/or painful eyes
- small defects that can be seen on the iris or conjunctiva
Malignant melanoma of the eye is often diagnosed through an examination of the eye using an ophthalmoscope. An ophthalmoscope is a device that enables your doctor to see and examine the structures of the eye. If your doctor detects a tumor in the eye, additional tests may be ordered to confirm diagnosis. These include:
- a CT scan to check for metastasis to the brain
- an ultrasound of the eye
- an MRI of the head and brain
- a skin biopsy
Treatment for malignant melanoma of the eye will depend on the specific type of tumor that you have. If the tumor is small and is not growing rapidly, your doctor may not recommend any treatment. Instead, he or she will monitor your tumor to make sure that it does not grow, spread, or change.
If your tumor is large or has the potential to metastasize to other organs in the body, your doctor may recommend more aggressive treatment. Malignant melanoma of the eye can be life threatening if it spreads to other organs.
The goal of treatment is to limit the growth of the tumor and prevent it from spreading. This can be accomplished through the following treatments:
- surgery to remove the eye
- radiation therapy to kill the cancer cells inside the eye
- irradiation therapy that delivers beams of X-rays to kill cancer cells in the eye
- laser therapy
The type of tumor determines the outlook for a patient with malignant melanoma of the eye. If the malignant melanoma is a primary tumor and has not spread to other parts of the body, the prognosis for the patient is quite good.
With treatment, a majority of patients will survive five years after diagnosis. However, treatment for malignant melanoma of the eye may result in vision loss, damage to the eye, or in some cases, removal of the eye.
For patients with secondary malignant melanoma of the eye, or for those whose primary tumor spreads to other organs in the body, the prognosis is not as favorable. Survival rates decline significantly depending on the additional organs that are affected by the cancer.
You can help prevent malignant melanoma of the eye by getting an annual eye exam and also by avoiding excessive exposure to sunlight. Sunglasses with ultraviolet protection should be worn between the hours of 10 a.m. and 2 p.m., when the sun’s rays are the strongest.