Background: Optic neuropathy due to an aneurysm is relatively rare, with only a few small case series on this topic, and no randomized trials having been published until now. As such, the functional prognosis and treatment for aneurysm-induced optic neuropathy remain controversial.
Objective: We quantified optic nerve injuries using an objective index (the visual impairment score) and evaluated prognostic factors of postoperative visual function.
Materials and methods: Of 960 patients treated for an unruptured intracranial aneurysm, 18 (1.9%) patients had optic neuropathy. Visual acuity and visual field were assessed before surgery and 6 months' postoperatively. Cases were classified on the basis of treatment modality (coil embolization or flow alteration [FA]) and prognostic factors of the two treatment groups.
Results: Of the 18 patients with an intracranial aneurysm and optic neuropathy, 12 (67%) were treated using coil embolization and 6 (33%) were FA. Visual function improved after surgery in 8 patients (44%), 5 (42%) in the coil embolization group, and 3 (50%) in the FA group. The visual function remained stable after surgery in 6 (33%) patients and worsened in 4 (22%). Patients with an aneurysms <15 mm in size had a favorable outcome (P = 0.05).
Conclusions: Surgical treatment improved vision in 44% of cases, with no difference in the prognosis of coil embolization and FA and no effect of the duration of symptoms on outcomes. Further, the prognosis of visual function recovery was better for aneurysms <15 mm in diameter.
Keywords: Coil embolization; intracranial aneurysm; optic nerve neuropathy; parent artery occlusion; visual impairment score.