Melanoma is a type of cancer that develops in the cells called melanocytes that produce melanin the pigment that gives your skin its color. Your eyes also have melanin-producing cells and can develop melanoma. Eye melanoma is also called ocular melanoma.
Ocular melanoma accounts for approximately 5-12% of all melanoma cases. Some studies suggest that fair skin type and exposure to UV light may be risk factors. Ocular melanoma tends to occur slightly more often in males than in females and overall risk tends to increase with age. Approximately 2,500 adults are diagnosed with ocular melanoma every year. There is no known cause, though incidence is highest among people with lighter skin and blue eyes.
Most eye melanomas form in the part of the eye you can't see when looking in a mirror called the uvea this is called uveal melanoma. This makes eye melanoma difficult to detect. In addition, eye melanoma typically causes early signs or symptoms. Very rarely, melanoma starts in the conjunctiva, which is the outer lining of the eye. This is called conjunctival melanoma. These two types of eye melanoma are treated in slightly different ways. Treatment is available for eye melanomas. Treatment for some small eye melanomas may not interfere with your vision. However, treatment for large eye melanomas typically causes some vision loss.
The cause of eye melanoma is not known. The main risk factor for skin melanoma is exposure to ultraviolet (UV) rays, either from the sun, sunbeds or sunlamps. Eye melanoma is more common in people with fair or red hair, blue eyes and whose skin burns easily. But it's still not clear whether there is a link between UV ray exposure and eye melanoma. Eye melanoma is more common in people who have atypical mole syndrome, which is also called dysplastic naevus syndrome. People with this condition often have more than 100 moles on their body, and are more likely to develop a skin melanoma. Conjunctival melanoma usually develops from a rare condition called primary acquired melanosis (PAM), which causes brown or dark patches (pigmentation) on the conjunctiva. Sometimes the melanoma will develop from an existing freckle or mole on the conjunctiva.
Treatment for eye melanoma may include radiotherapy, surgery, transpupillary thermotherapy (TTT), cryotherapy, chemotherapy eye drops, photodynamic therapy (PDT). You may have one or a combination of these treatments. Your treatment plan will depend on factors such as the size and position of the tumour, your general health and your eyesight. Uveal and conjunctival melanomas are treated in slightly different ways. But the aim is to destroy the cancer cells, while doing as little damage to your eyesight as possible. Some treatments for eye melanoma are very specialised and are only available at a few hospitals in the UK. You may have to travel to one of these hospitals for your treatment.