Incidence of retinoblastoma in Malawi.

The annual incidence of retinoblastoma in Malawi seems to be two cases per 100,000 children under five or one case per 10,000 live births. A higher frequency of one case per 21,700 to 17,900 children under five or one per 4,340 to 3,580 live births has been found in the Zomba and Mangochi districts. Analyzing the cases according to sex and laterality, 61.1 percent of the unilateral cases were girls and 58.3 percent of the bilaterals were boys. Among boys, 33.3 percent were bilateral while unilateral involvement of the left eye was found in 19.1 percent. Among the girls, the frequency of bilateral cases was 18.5 percent while the unilateral involvement of right and left eye was nearly similar.