Treating Eye Melanoma by Location and Size

The main factors in deciding on treatment for eye melanoma include the location and size of the cancer, as well as the likelihood of saving vision in the eye. There is not much advantage in saving an eye if a small melanoma in a crucial place has already destroyed vision in the eye. On the other hand, doctors will not necessarily want to remove an eye that functions normally even if the tumor is large. Because of this, your treatment plan will depend on your situation, and could be different than what's described here.

It’s important to keep in mind that outcomes and quality of life both tend to be similar over time for people who have had an eye removed (enucleation) and those who have had radiation therapy. Radiation therapy is more likely to preserve some vision in the eye, especially during the first few years after treatment, but studies have found that people who have had radiation therapy are also more likely to be more anxious about the chance of the cancer coming back. Be sure to talk with your doctor before treatment about what is most important to you.

Choroidal melanomas

Treating melanomas that start in the choroid depends on the size of the tumor and how well the eye functions. The smaller the tumor, the less likely surgery will be needed, unless the eye is badly damaged or vision is lost.

Small melanomas: There are often several options for treating small choroidal melanomas. Both you and your doctor should decide which option is best for you:

• Careful observation (also known as watchful waiting). Not all of these melanomas grow quickly and need to be treated right away. And sometimes, it’s very hard for the doctor to even be sure if a spot on the choroid is truly a melanoma. If the tumor is very small, watching it closely (sometimes every 3-4 months) and treating it only if it starts to grow is often a reasonable option.
• Radiation therapy, such as brachytherapy (plaque therapy), proton beam therapy, or stereotactic radiation therapy
• Laser therapy, including transpupillary thermotherapy (TTT), most often along with brachytherapy
• Surgery, which may require removing only the tumor or might need to be as extensive as enucleation (removing the entire eye). This might be necessary if the eye is severely damaged by the tumor.

Medium-sized melanomas: These tumors can usually be treated by many of the same approaches used for small melanomas:

• Radiation therapy, such as brachytherapy (plaque therapy), proton beam therapy, or stereotactic radiation therapy
• Laser therapy, including transpupillary thermotherapy (TTT) or laser coagulation, along with brachytherapy
• Surgery, which may require removing only the tumor or might need to be as extensive as enucleation (removing the entire eye). This might be necessary if the eye is severely damaged by the tumor.

Once again, the choice of treatment is a decision that should be made by both you and your doctor. Radiation and surgery appear to be about equally effective. Radiation offers the best chance of preserving vision in the eye, but some people who have radiation may eventually need surgery, too.

Large melanomas: The standard treatment for these cancers is usually radiation. Proton beam therapy and stereotactic radiation therapy are usually used first. Additional treatment with surgery or lasers may also be considered if the radiation does not work completely. 

Surgery with enucleation (removal of the entire eye) is the preferred surgery for large melanomas when radiation is not an option. Enucleation might also be considered for cancers that take up more than half of the eye orbit, that cause significant pain, or that have caused loss of vision in the eye.  In rare cases where the cancer has grown extensively outside of the eye, the doctor might recommend removing other structures in the eye socket, such as muscles or part of the eyelid, as well.

Iris melanomas

Melanomas of the iris (the colored part of the eye) are usually small, slow-growing tumors. One option for people with an early stage iris melanoma is to watch it closely to see if it grows. A series of special photographs are taken to help monitor the tumor. If it begins to grow, treatment may be surgery or radiation therapy (in certain situations).

If surgery is recommended, the amount of eye tissue to be removed depends on the extent of the cancer. Types of surgery for early iris melanomas include:

• Iridectomy (removal of part of the iris)
• Iridotrabeculectomy (removal of part of the iris, plus a small piece of the outer part of the eyeball)
• Iridocyclectomy (removal of a portion of the iris and the ciliary body)
• Enucleation (removal of the eyeball)

Ciliary body melanomas

These rare cancers can be treated with either surgical removal of the tumor, if it is small enough, or radiation therapy. In more advanced cases or if there is serious eye damage, enucleation (removal of the eyeball) may be needed.

Conjunctival melanomas

Although rare, melanomas of the conjunctiva tend to be more aggressive than most uveal melanomas. They are more likely to grow into local structures and spread to distant organs like the liver and lungs where the situation can become life-threatening. Treatment is focused on completely removing the tumor with surgery and giving adjuvant treatment with radiation or topical chemotherapy (with interferon or Mitomycin-C) to reduce the likelihood of metastases (tumor spread).

Because of the aggressive nature of this tumor, a biopsy of the tumor may be done initially to look for certain traits that can predict the likelihood the cancer will spread or recur. If the chances are on the high side, more frequent follow-up exams after treatment may be recommended.

Advanced and recurrent melanomas

Most uveal melanomas are still only within the eye when they are first diagnosed. It is rare for the cancer to have already spread outside of the eye. But unfortunately, in about half of all patients the melanoma will come back at some point after treatment.

Cancer that comes back after treatment is called recurrent. Recurrence can be local (in or near the same place it started) or distant (spread to organs such as the lungs or liver).Treating melanomas that come back depends on many factors, including where the cancer recurs and what type of treatment was used initially.

Cancers that recur within the eye (intraocular recurrence) are usually treated by removing the eye (enucleation).

When melanoma recurs outside the eye (called extraocular recurrence), it most often comes back in the liver. It might also come back in other areas, like the lungs or bones. These cancers are often hard to treat.

If the cancer is only in the liver, different types of treatments might help keep the cancer under control or help relieve symptoms. These include surgery (if there is only one or a few tumors), radiation therapy, destroying (ablating) tumors by heating or freezing them, or injecting drugs or other substances into the liver to try to kill the tumors or cut off their blood supply. Tumor ablation and radiation might also be used for tumors that have spread to other parts of the body, such as the lungs.

If these treatments can’t be used, medicines that reach all parts of the body might be helpful for some people. Lab tests might be done on your blood or cancer cells to see if immunotherapy or targeted drugs might be good treatment options. Chemotherapy might be another option for some people.

Because current treatments for advanced eye melanomas are limited, clinical trials of newer treatments might also be a good option. (See What's New in Eye Cancer Research? for some examples of newer treatments now being studied.)