A Case of Compressive Optic Neuropathy Caused by Orbital Emphysema

Abstract

Purpose: We report a patient with compressive optic neuropathy (CON) in whom visual acuity (VA) was restored after removing conjunctival emphysema through the conjunctiva.Case summary: A 55-year-old man was transferred to emergency department complaining of decreased VA in the right eye after trauma to the right temporal side of the head. The best-corrected visual acuity (BCVA) was 0.6 in the right eye. We confirmed a relative afferent pupillary defect and limited eye movement inferiorly in the right eye. The patient had blown his nose several times while being transferred to the hospital. On silt-lamp examination, there was conjunctival emphysema of the right eye. Orbital computed tomography showed a medial wall fracture of the right orbit and orbital emphysema above the optic canal. The P100 wave was delayed in the visual evoked potential (VEP) exam, and there was a decreased peripheral visual field on the Humphrey visual field test. Based on these findings, we diagnosed CON and treated him accordingly. To decompress the intra-orbital area, we injected mannitol intravenously, applied intraocular pressure-lowering and antibiotic eye drops in the right eye, and removed part of the conjunctival emphysema through the conjunctiva. At the 3-week follow-up, the BCVA had improved to 1.0 in the right eye with a normalized P100 wave on the VEP exam.Conclusions: In a case of CON caused by orbital emphysema after trauma, it is important to decrease the intra-orbital pressure as soon as possible to enable a good prognosis for the VA.