Visual dysfunction and neurodegeneration caused by severe inflammatory optic neuropathy after coil embolization of a paraclinoid aneurysm: illustrative case.

BACKGROUND:Visual impairment due to delayed optic neuropathy is a rare complication of the endovascular treatment of paraclinoid aneurysms. An inflammatory response induced in the treated aneurysm wall is a known mechanism underlying this pathophysiology. The authors describe a case with severe and progressive optic neuropathy leading to neuronal degeneration and severe visual dysfunction. OBSERVATIONS:A 42-year-old female with a history of surgical clipping for a paraclinoid aneurysm presented with a recurrence. Although the patient was unaware of any visual dysfunction, a preoperative ophthalmological examination revealed mild inferior quadrantanopia in the left eye. The coil embolization procedure was uneventful; however, the following day, the patient experienced progressive visual impairment, which worsened despite the initiation of steroid therapy. Ophthalmological examination revealed a severe decrease in visual acuity and further deterioration of the visual field. Magnetic resonance imaging showed remarkable swelling and edema of the left optic nerve adjacent to the treated aneurysm. Despite continued steroid therapy, the patient's visual function did not recover well due to subsequent optic nerve degeneration. LESSONS:Optic neuropathy after endovascular procedures can lead to severe visual dysfunction. Careful management is essential, particularly when treating a symptomatic paraclinoid aneurysm, even if symptoms are only apparent on detailed examination.