Invasion of the optic nerve by retinoblastoma: a clinicopathological study.

We have studied all cases of optic nerve invasion in retinoblastoma seen at the Edward S. Harkness Eye Institute in New York since 1925. Since 1959 optic nerve invasion has been less extensive--suggesting earlier diagnosis and management. Since 1959 there has also been an increase in the number surviving. Survival correlates with the extent of spread to optic nerve, choroid and extrabulbar tissues. Current and future therapy are discussed. The importance of subpial extension of retinoblastoma is noted and its relationship to the mode of therapy is emphasized.