Traumatic Optic Neuropathy Aggravated by Orbital Emphysema after Orbital Fracture

Purpose: To report a case of traumatic optic neuropathy aggravated by orbital emphysema after an orbital fracture. Case summary: A 19-year-old man with no specific medical history was referred for a right orbital fracture caused by blunt trauma to the supraorbital rim of the right eye. Computed tomography (CT) showed a right orbital fracture involving the inferomedial wall and inferomedial strut. The corrected visual acuity was 0.4 in the right eye (RE) and 1.0 in the left and the intraocular pressure was 15 and 18 mmHg, respectively. Restriction on downgaze, abduction, and an indefinite relative afferent pupillary defect (RAPD) were observed in the RE. Fundus exam was non-specific other than commotio retinae on the temporal side of the macula in the RE. After 12 hours post trauma, the visual acuity of the RE had decreased to light perception. Definite RAPD was observed with optic disc swelling on the fundus photo and optical coherence tomography. Orbital CT showed air shadows, which were not seen on the initial evaluation, adjacent to the optic disc. We diagnosed traumatic optic neuropathy aggravated by orbital emphysema. High-dose intravenous steroid was given for 3 days. Despite a lateral canthotomy and cantholysis to decompress the right orbit, visual acuity did not improve above counting fingers. Conclusions: Increased intraorbital pressure and congestion caused by orbital emphysema may exacerbate traumatic optic neuropathy. Therefore, close observation is required.