Optic Canal Decompression With Dural Sheath Release; A Combined Orbito-Cranial Approach To Preserving Sight From Tumours Invading The Optic Canal

Abstract

Purpose: The purpose of this case series is to describe an orbito-cranial surgical approach for the management of optic nerve compression secondary to tumours extending into the optic canal.Method: We present a retrospective, observational case series of 4 patients who underwent surgery aimed at improving or stabilising vision for tumours invading the optic canal. In all cases tumours were not amenable to complete resection due to their intrinsic relation to important structures including: the internal carotid artery, cavernous sinus, optic and oculomotor nerves. All patients underwent combined orbito-cranial surgery consisting of craniotomy, debulking of the tumour, transcaruncular orbital and optic canal decompression with release of the dural sheath overlying the optic nerve via the craniotomy approach. Visual acuity was the primary outcome measure.Results: Four patients, aged 42, 44, 61 and 78 years, three with spheno-orbital meningioma and one with cerebral sino-nasal adenocarcinoma were included in the study. Mean postoperative follow-up time was 26, 19 and 15.6 months. The fourth patient died at 2.9 months post-surgery due to high grade aggressive cerebral adenocarcinoma. Postoperative visual acuity improved by greater than 4 lines of Snellen acuity in 2 patients at 26 and 19.1 months. Two patients decreased from counting fingers vision to perception of light at last follow-up.Conclusions: In cases of non-resectable meningioma extending into the optic canal with secondary optic nerve compression, a combined surgical approach with optic canal decompression and dural sheath release may help preserve and even improve vision in certain cases.