Melanoma is a cancer that develops from cells called melanocytes. Melanocytes give our skin its colour. Melanoma usually develops in the skin. But because there are melanocytes in different parts of the body, it can start in other places, such as the eye. This is called uveal melanoma. It is the most common type of cancer to affect the eye, although it's still quite rare. Very rarely, melanoma starts in the conjunctiva, which is the outer lining of the eye. This is called conjunctival 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.
Small melanomas may be treated with:
Melanoma of the uveal tract (iris, ciliary body, and choroid), though rare, is the most common primary intraocular malignancy in adults. The mean age-adjusted incidence of uveal melanoma is approximately 4.3 new cases per million people, with no clear variation by latitude. Males have a higher incidence than females (4.9 vs. 3.7 per million). The age-adjusted incidence of this cancer has remained stable since at least the early 1970s.