Optic Nerve Obscuration in Retinoblastoma: A Risk Factor for Optic Nerve Invasion?

Background: The objective of this study is to evaluate the risk of optic nerve invasion associated with optic nerve obscuration at diagnosis or persisting during treatment.

Methods: Retrospective review from 2011-2016 of patients with advanced retinoblastoma (Group D/E) with complete obscuration of the nerve at diagnosis and a second group of patients with persistent, complete obscuration throughout treatment.

Results: Advanced retinoblastoma was diagnosed in 102 eyes of 86 patients. The optic nerve was obscured in 69 eyes (68%) at diagnosis. Of these, 30 (43%) underwent salvage therapy and 39 (57%) primary enucleation. Histopathologic analysis of primarily enucleated eyes showed 41% prelaminar and 15% postlaminar invasion. Four eyes in the salvage group demonstrated persistent nerve obscuration; 2 were subsequently enucleated without evidence of nerve invasion. Average follow-up was 23.5 months (range 1-62 months).

Conclusions and Relevance: Optic nerve obscuration at diagnosis may be associated with postlaminar optic nerve invasion. While persistent, complete obscuration of the optic nerve by retinoblastoma during treatment is a poor prognostic sign for both globe salvage and vision, it does not appear, in this small cohort, to increase the risk of optic nerve invasion. With appropriate control of the intraocular tumor, these eyes can be salvaged.