What is ocular melanoma?
Ocular melanoma is a rare form of melanoma, accounting for approximately 3.7 % of all melanoma cases, according to the International Journal of Clinical and Experimental Pathology. It develops from melanocyte cells in the eye, usually starting in the middle of the three layers of the eye called the uvea. It can also develop on the conjunctiva, which is the outermost layer of the eye.
What are the symptoms?
Ocular melanoma symptoms usually present itself as a dark spot on the iris, a change in the shape of the pupil, poor or blurry vision or as the appearance of flashing lights or floating specks. So what are ocular melanoma treatment options?
Ocular melanoma treatment options
Once ocular melanoma is diagnosed, treatment depends on where the melanoma is located, its size and the patient’s general health.
Ocular melanoma is difficult to treat as it is resistant to many traditional systemic therapies, which are typically drugs that spread throughout the body to kill cancer cells. This is why early diagnosis and treatment are especially vital. If the melanoma tumor is small, sometimes a doctor will watch the melanoma and see if it develops and enlarges overtime before taking action.
Treatment for ocular melanoma can be treated through radiation or surgery. Sometimes more than one treatment is used.
Radiation therapies involve using high-energy rays that are used to kill or damage cancer cells and prevent them from growing. There are several forms of radiotherapy used to treat ocular melanoma:
Plaque therapy, also known as brachytherapy, is the most common form of radiotherapy treatment. According to the Ocular Melanoma Foundation, in this type of therapy, a small disc-shaped shield called a plaque that is covered in radioactive seeds is adhered to the outside of the eye, covering the tumor. It is left on for a few days and then removed. This has become the standard practice for the majority of ocular melanoma patients with small or medium-sized tumors.
Teletherapy, also known as external beam radiotherapy, targets the tumor through the front of the eye with charged particles that damage the cancer cells. The beam of light is directed by sewing surgical clips around the corner of the eye at the base of the tumor. Eye movements are closely monitored to keep the radiation targeted on the tumor, minimizing radiation damage in other areas of the eye.
This form of radiotherapy targets high-intensity doses of radiation precisely to the tumor in one session. It does this by pointing a large number of radiation beams at the tumor from many different angles at once or by directing a single beam around the tumor from many different angles.
For large tumors and melanomas on the iris, surgical removal of the tumor is often recommended. If the melanoma returns after radiation treatments, surgery may also be the chosen treatment route. There are several forms of surgical treatment. TheMelanoma Research Foundation lists the most common types used:
Enucleation: Enucleation is the removal of the eye entirely. This is sometimes necessary when the tumor has grown too big.
Iridectomy: This refers to removing part of the iris where the tumor is located.
Iridocyclectomy: Iridocyclectomy is the removal of part of the iris and the ciliary body (the part of the eye that connects the iris to the choroid, the vascular layer of the eye) next to it where the tumor is present.
Trans-Sclera LocalResection: This is when the tumor is taken out through an opening in the wall of the eye. This usually occurs when the tumor is large, and it is typically followed-up with a radioactive plaque placed over the treated area to help reduce the chances of the tumor returning.
Trans-Retinal Endoresection: This is when the tumor is removed through a hole in the retina. It is often done when the tumor is too close to the optic nerve and it is typically followed up with laser treatment to kill any cancer cells that were missed and to help prevent cancer from returning.
Metastatic Ocular Melanoma
Once melanoma has spread to other areas of the body or metastasized, treatment options are generally not good. At this point, treatments will vary depending on where cancer has spread and its severity. Many treatments will be palliative.
This is not an exhaustive list. There are many new clinical trials being developed to fight ocular melanoma, especially throughout the US and Europe. Consult your doctor for other treatment options and possible clinical trials available near you.