Evaluation the risk of optic nerve invasion associated with optic nerve obscuration in advanced retinoblastoma

Abstract

Objective: To evaluate the potential association between optic nerve invasion and optic nerve obscuration during treatment of advanced retinoblastoma. Methods: Retrospective case series study. Medical records of 77 patients (77 eyes) with advanced retinoblastoma (Group D/E) who were treated with primary or secondary enucleation in the Ophthalmology Department of Peking University People's Hospital from January 1st 2012 to December 31th 2015 were retrospectively reviewed. RetCam photographs under general anesthesia at diagnosis and each subsequent follow-up were evaluated for complete obscuration of the optic nerve. The primary endpoints included prelaminar invasion, postlaminar invasion and optic nerve transection invasion. Group difference was calculated with chi-square. Results: There were 46 boys and 31 girls in the study. The mean age at the first diagnosis was (27.1±22.1) months. The optic nerve was obscured in 62 eyes (80.5%) at the first diagnosis and 61 eyes (79.2%) at the last ocular examination prior to enucleation. Twenty-nine eyes (37.7%) underwent primary enucleation. Forty-eight eyes (62.3%) were treated with eye-preserving therapy, followed by enucleation. Fourteen eyes (18.2%) were in Group D and 63 eyes (81.8%) were in Group E. Histopathologic analysis of enucleated eyes without optic nerve obscuration (16 eyes) showed prelaminar invasion in 7 eyes, postlaminar invasion in 2 eyes and optic nerve transection invasion in 0 eyes. Histopathologic analysis of enucleated eyes with optic nerve obscuration (61 eyes) showed prelaminar invasion in 26 eyes, postlaminar invasion in 9 eyes and optic nerve transection invasion in 4 eyes. The difference between two groups did not achieve statistical significance (P=0.935, 1.000, 0.296). Histopathologic analysis of enucleated eyes with persistent complete obscuration of the optic nerve showed a high risk factor in 10 eyes (10/40), while in 1 eye (1/8) the optic nerve was visible at the initial presentation and obscured before secondary enucleation (P=0.529). Conclusion: Optic nerve obscuration at the last examination prior to enucleation may not be associated with postlaminar optic nerve invasion in advanced retinoblastoma. (Chin J Ophthalmol, 2020, 56: 681-687).