Melanomaisamalignanttumouroriginatinginthepigment-formingcells（melanocytes）oftheeye.Themostcommonsiteisthechoroidlayer,whichislocatedbetweenthesclera（whitefibroustissueoftheoutsideoftheeye）andretina（innermostlayer）.Thechoroidcontainsbloodvesselsaswellaspigment.ThediseaseincidenceinEuropeandtheU.S.isapproximately7.5casesannuallypermillionpopulation.Theoutlookforlocalcuredependsstronglyonthesizeofandgrowthrateofthetumour.Thefive-yearsurvivalexpectationisapproximately70%forpatientstreatedeitherwithenucleation（surgicalremovaloftheeye）orradiotherapy.Theadvantagewithradiotherapyisthattheaffectedeyecanbesavedinmostcasesandvisionmaybepreserved.
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