The retinoblastoma is an eye tumor of childhood that arises in the retina and represents the most common intraocular malignancy of infancy and childhood. Tumor formation usually begins with mutation in both alleles of the retinoblastoma tumor suppressor gene RB1, followed by a series of other genetic alterations that correlate with the clinical stage and pathologic findings of the tumor. In retinoblastoma, mutation of RB1 leads to dysfunction or absence of the Rb protein. These mutations promote tumour development by deregulating the E2F family of transcription factors leading to uncontrolled cell cycle progression.