Optic Neuropathy, Secondary to Ethmoiditis, and Onodi Cell Infl ammation during Childhood: A Case Report and Review of the Literature Marina Mazzurco 1 Piero Pavone 1 Milena Di Luca 2 Pierluigi Smilari 1 Elena Pustorino 1 Agata Fiumara 1 Paola Di Mauro 2 Filippo Greco 1 Salvatore Cocuzza 2 1 Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy 2 ENT Unit, Department of Otorhinolaryngology, University of Catania, Italy Neuropediatrics Address for correspondence Piero Pavone, MD, PhD, Department of Pediatrics, University of Catania, Via Santa Sofia 78, 95124 Catania, Italy (e-mail: ppavone@unict.it). Introduction Optic neuropathy refers to damage of the optic nerve, which can be linked to demyelinating, inflammatory, ischemic, traumatic, compressive, toxico/nutritional, or hereditary events. 1–3 Optic neuropathies are rare during childhood, but compressive/tumoral and inflammatory events are the most frequent etiologies of childhood optic neuropathies. 1 Optic nerve impairment is the cause of more or less gradual visual loss, discoloration, visual field defects and other ophthalmologic and neurologic involvements. The optic nerve is topographically correlated with different brain structures, including the Onodi cell (spheno-ethmoidal air cell). 2,3 The Onodi cell was first described by Adolf Onodi in 1904 2 : it is an anatomical variant of the posterior ethmoid cells surrounding the optic nerve and ventilated by the sphenoid sinuses. When the migration of the posterior ethmoid cells is complete, the Onodi cell is located around the optic nerve. Therefore, there is a close anatomical rela- tionship between the Onodi cell and the optic nerve, which can lead to ophthalmologic complications. In the literature, the incidence of Onodi cells has been reported to range from 7 to 14% in radiological findings. 2,3 Anatomical studies of Onodi cells have been reported in up to 60% of samples. 3 Keywords ► optic neuropathy ► ethmoiditis ► Onodi cell ► optic neuritis Abstract Optic neuropathy consists of several etiological events. The primary etiologies of its acute form include optic neuritis, ischemic optic neuropathy, inflammatory (non- demyelinating) disorders, and trauma. Its subacute and chronic forms are most often linked to compressive, toxic, nutritional, or hereditary-genetic causes. Visual loss, dyschromatopsia, and visual field defects are the presenting symptoms. The Onodi cell (sphenoethmoidal air cell) is an anatomic variant located laterally and superior to the sphenoid sinus; it is closely related to the optic nerve. Onodi cell disorders are rare and may be unnoticed in differential diagnoses of patients with ocular and neurological manifestations. Here, we present the case of a 12-year-old boy with headache and acute loss of sight characterized by hemianopsia in the left eye and retrobulbar optic neuropathy caused by left sphenoethmoidal sinusitis with the presence of Onodi cell inflammation. The diagnosis was confirmed by multilayered paranasal computed tomography and cerebral magnetic resonance imaging. Therapeutic treatment resulted in gradual improvement: at the 2-week follow-up, the patient no longer had headaches and his visual acuity returned to normal. Inflammation of Onodi cells should be considered in children with headache and abnormal vision. Piero Pavone's ORCID is https://orcid.org/0000-0002-5600-9560. received February 26, 2019 accepted after revision May 15, 2019 © Georg Thieme Verlag KG Stuttgart · New York DOI https://doi.org/ 10.1055/s-0039-1693156. ISSN 0174-304X. Review Article Downloaded by: Universitätsbibliothek. Copyrighted material.