2026 Poster Presentations
P016: ENDOSCOPIC ENDONASAL APPROACH FOR OPTIC NERVE SHEATH FENESTRATION AND BONY DECOMPRESSION OF THE OPTIC CANAL FOR TREATMENT OF OPTIC NERVE GLIOMA IN AN 11-YEAR-OLD BOY
Christopher J Carr; David Baker; Justin Abes; Karen Asher; George Davies; Kenneth Nyrd; Colleen McDonough; John Henson; Fernando Vale; Khoi Nguyen; Muhammad Ali; Medical College of Georgia
Introduction - Optic nerve gliomas (ONG) are low-grade, diffusely-infiltrative tumors that form from glial cells within the optic nerve. They are most common in children and have been associated with neurofibromatosis type 1 (NF1). As they grow, they can cause mass effect on the optic nerve leading to progressive vision loss. Management options include observation, chemotherapy, radiation, and surgery.
Methods - We present a case of ONG in an 11-year-old boy treated with a novel endoscopic endonasal approach for bony decompression of the optic canal and optic nerve sheath fenestration.
Results - An 11-year-old boy negative for NF1 presented with a 3-month history of intermittent right-eye visual obscurations increasing in frequency. MRI showed enlargement and signal within the right optic nerve consistent with intraorbital ONG.
An endoscopic, endonasal, trans-sphenoidal, trans-tubercular approach was employed for bony decompression of the canalicular component of the right optic nerve 270-degrees around at the pre-chiasmatic sulcus and medial orbital wall and to fenestrate the optic sheath. Once the sphenoid sinus was accessed, we used an irrigated 4 mm coarse diamond bit to drill the tuberculum sella extending laterally over the optic canal and all the way to the orbit. We used a Cottle elevator to fracture the lamina papyracea and thereby decompress the medial wall of the orbit. Once the medial wall of the optic canal was decompressed, we used a 2-mm coarse diamond burr to drill the roof and floor of the optic canal for 270 degrees of bony decompression. Then using an 11 blade we fenestrated the optic sheath along the length of the exposed optic canal.
The patient did well and was discharged on postoperative day 2. 10 months postoperatively, he was undergoing adjuvant chemotherapy with carboplatin and vincristine chemotherapy in accordance with Children's Oncology Group (COG) protocol. He continued to do well, with no new deficits. Interval imaging showed decreased size of the mass.
Conclusion - ONGs are slow-growing tumors that can cause progressive visual loss secondary to mass effect on the optic nerve. As they progress, they tend to grow from the orbit into the optic chiasm. They can be difficult to resect due to their eloquent location intrinsic to the optic nerve. Chemotherapy and radiation therapy are generally successful, with 5-year progression-free survival as high as 90% in some series. Our surgical approach focused on direct decompression of the optic canal and nerve sheath fenestration, with the goal to prevent new vision loss. Due to the facts that our patient did not have NF1, along with the progressive symptoms, our multi-disciplinary tumor board came to the conclusion that he was more at risk for disease progression than an incidentally found tumor in an NF1 patient might be and that a minimally-invasive endoscopic endonasal approach for bony decompression of the optic nerve could result in superior outcomes in terms of preventing progression of his visual symptoms. Our surgical approach provided a direct minimally-invasive approach for optic nerve decompression even in a pediatric population, and our patient continues to do well.