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