Melanoma of the uvea or choroidal melanoma
Our skin has pigment cells, called melanocytes. Pigment cells in your skin can develop into a mole, or “nevus.” That mole or nevus can grow and become a malignant melanoma.
Like your skin, the eye has a tremendous amount of pigment cells, or melanocytes. Pigment cells in the eye can also develop into a mole, or nevus. Likewise, malignant melanoma can originate inside the eye, within the “uvea” or choroidal layer of the eye. The melanoma originates from pigmented cells in the eye.
Melanoma inside the eye may decrease vision or cause a shadow in vision and thus come to attention. Alternatively, melanoma inside the eye may have no symptoms and be discovered on a regular routine eye exam.
Malignant melanoma inside the eye can eventually travel via the bloodstream outside the eye, often to the liver, lung, or other body organs, and eventually cause death from metastasis. Thus melanoma inside the eye needs to be treated.
The eye can be removed. Even if the eye is removed as soon as the tumor is discovered, there is a chance that microscopic cells from the melanoma have already traveled outside the eye, perhaps to the liver. We recommend a medical exam and PET scan to look to see if melanoma has traveled outside the eye at the time of initial diagnosis. However, it is very important to realize that the PET scan or CT scan may be negative or normal, but small cells from the eye melanoma may have still gotten outside of the eye. Those cells may simply be undetectable in the beginning and only show up years later.
The alternative to taking the eye out is to treat the eye with radiation. An NIH clinical trial called the COMS study (see links below) showed that, for medium size tumors, survival is the same whether you take the eye out or whether you treat with radiation. The radiation usually reduces vision in the eye, but often some degree of vision is preserved.
Radiation to the eye can be performed in two ways. Here in Oklahoma City, we treat melanoma inside the eye with Iodine 125 plaque radiation.We sew a special radiation treated plate or “plaque” to the eye and let the plaque stay there for 5 days, during which the plaque irradiates the tumor. The patient stays in the hospital during those 5 days. This plaque technique was used in the COMS study.
The alternative technique is proton beam therapy. In terms of which works best, for the majority of tumors Iodine 125 plaque therapy and proton beam therapy work equally well. For some tumors, especially tumors wrapped around the optic nerve (“circumpapillary tumor”), proton beam therapy is better.
If a patient wants proton beam therapy rather than Iodine 125 therapy, or the patient’s tumor is a “circumpapillary tumor” that will do better with proton beam, Dr. Dahr will refer you to Evangelos Gragoudas, M.D. at the Francis Burr Proton Therapy Center at Harvard University in Boston. Dr. Gragoudas developed proton beam therapy for the eye 30 years ago. His team is the most experienced in the world in proton beam therapy for the eye.
For patients and their primary care doctors and oncologists:Patients with uveal melanoma or suspected of having uveal melanoma should have a baseline medical examination with imaging.