When you think of melanoma, you most likely think of skin cancer, however, melanoma can also occur in the melanocytes (cells that produce the pigment melanin) of the eye. Around 2,000 new cases of melanoma of the eye, or ocular melanoma, are diagnosed each year, making up between five and 12 percent of all melanoma cases.
The exact cause of ocular melanoma is not known, however, as with skin cancer, it is more common in those who are caucasian, with light color eyes. The risk factor also increases with age. People with dysplastic nevus syndrome, which is characterized by a high amount of moles, have a higher risk of developing melanoma of the eye. In addition, exposure to the sun or tanning beds is thought to increase the risk.
This cancer develops in the uvea, the middle region of your eye and is therefore hard to detect because you can’t see this part of your eye by looking in a mirror. During the early stages there usually aren't any symptoms. It is frequently found in routine eye exams. For people with high risk factors, it is important to have regular eye exams.
According to the American Academy of Ophthalmology, as the cancer develops you might notice symptoms such as:
- A dark spot on your iris
- Blurred vision
- Sensation of flashing lights
- Loss of vision
- Changes in the shape of your pupil
Diagnosing ocular melanoma
If your ophthalmologist thinks you might have ocular melanoma or if you begin to experience symptoms, your doctor will send you for additional testing, which might include:
Ultrasound of the eye which uses sound waves to create images of the inside of your eye
Fluorescein angiography which uses a special camera to take pictures of the inside of your eye after a special dye has been inserted (the dye is inserted into your arm and travels to your eye.)
Biopsy which requires a small amount of eye tissue to be removed and examined in a laboratory, however, this method is not normally used or needed to diagnose ocular melanoma
As with skin cancer, melanoma of the eye can spread to other areas of your body. Your doctor may refer you to a specialist to have additional tests completed to see if the cancer has metastasized, or spread, to your liver, lungs or bones.
If ocular melanoma is caught when your tumor is small, your doctor might want to “wait and watch” to see if the tumor grows. If it doesn’t grow, he may not recommend treatment right away but will instead continue to monitor the tumor. If your doctor believes treatment is necessary, there are several different types of treatment and together you can determine which would be best for you:
Surgery - Depending on the size and location of your tumor, your doctor might elect to remove the tumor and some surrounding tissue. If the tumor is large, your doctor might recommend having your entire eye removed (you will be given a temporary implant and then an artificial eye will be made)
Radiation - There are two different ways to receive radiation therapy to kill the cancer cells. The first uses a radioactive plaque which is temporarily held in place with stitches for several days. The second uses a machine to send radioactive beams into the tumor.
Laser treatment - In some cases, your doctor might recommend laser treatment, which uses laser beams to kill the cancer cells.
Because the cause of melanoma of the eye is not fully understood, there is no specific way to prevent it from occurring. Most doctors suggest wearing sunglasses to protect your eyes from the UV rays of the sun, however, it is not known how much UV light plays in the development of ocular melanoma.
For more information:
What is Ocular Melanoma?
Why Redheads Are at Greater Risk for Melanoma: A HealthCentral Explainer
Living with Melanoma
“Ocular Melanoma,” Date Unknown, Staff Writer, Melanoma Research Foundation
“What Is Ocular Melanoma,” Date Unknown, Staff Writer, EyeSmart, American Academy of Ophthalmology