Plication of the Optic Nerve: A Mechanism for Rapid Vision Loss in Optic Nerve Glioma

Optic nerve glioma (ONG) is the most common optic nerve tumor of childhood presenting with gradual proptosis, strabismus and visual loss. Rarely, such patients may develop acute loss of vision with worsening proptosis which has been associated with new hemorrhage or mucoid substance into the tumor. We postulate that plication of the optic nerve may be an etiology for rapidly progressive vision loss in this population.

Poster 283 Plication of the Optic Nerve: A Mechanism for Rapid Vision Loss in Optic Nerve Glioma Nailyn Rasool1, Ashley Campbell1, Michael Kazim1 Columbia University, New York, New York, USA 1 Introduction: Optic nerve glioma (ONG) is the most common optic nerve tumor of childhood presenting with gradual proptosis, strabismus and visual loss. Rarely, such patients may develop acute loss of vision with worsening proptosis which has been associated with new hemorrhage or mucoid substance into the tumor. We postulate that plication of the optic nerve may be an etiology for rapidly progressive vision loss in this population. Methods: A retrospective review of five patients with unilateral ONG was conducted. Both MRI imaging and surgical records were reviewed. MRI imaging of optic nerve caliber and "folding" was determined by analyzing the most acute angle present in the course of the optic nerve. In one patient, MRI resolution was insufficient to demonstrate folding of the optic nerve noted intraoperatively. Results: We reviewed 5 cases of unilateral ONG treated with resection of the nerve to prevent progression of the glioma to the chiasm. Three patients developed rapid loss of vision and proptosis over 6-8 weeks. The remainder had a more typical clinical course of gradually increasing proptosis and decreasing vision over months to years. MRI and surgical visualization of the ONG in patients with rapid visual loss demonstrated that all had an acute, 90 degree or less, fold in the optic nerve. Patients that did not experience acute vision loss had more obtuse bends in the optic nerve. Conclusions: Optic nerve tortuosity has been identified as a feature of "benign" gliomas. However, severe plication of the nerve as an etiology of rapidly progressive visual loss has not previously been discussed in the literature. Our cases demonstrate a new etiology for visual loss in patients with childhood ONG. Understanding of the degree of folding necessary to cause visual loss may enable us to determine which children are at risk for this complication and may warrant more proactive management. References: 1. McLeod, A Reeves. Acute blindness in childhood optic glioma caused by hematoma. JPOS. 1983; 20(1): 31-33 2. Anderson DR, Spencer WH. Ultrastructural and histochemical observations of optic nerve gliomas. Arc Ophthal 1970; 83: 324-335 3. Levin MH, Armstrong GT, Broad JH, Zimmerman R, Bilaniuk LT et al. Risk of optic pathway glioma in children with neurofibromatosis type 1 and optic nerve tortuosity or nerve sheath thickening. Br J Ophthalmol 2016; 100: 510-514 Keywords: Neuroimaging, Pediatric neuro-ophthalmology, Orbit, Optic nerve trauma and treatment, Tumors Financial Disclosures: The authors had no disclosures. Grant Support: None. 438 | North American Neuro-Ophthalmology Society