title: [A rare cause of optic neuropathy: Cassava].
abstract: BACKGROUND
  Cassava root is a staple food for almost 500 million people worldwide. Excessive consumption of it is a rare cause of optic neuropathy.
  
  
  METHODS
  Ten patients diagnosed with cassava root related optic neuropathy were included in this retrospective study. Diagnostic criteria were a bilateral optic neuropathy preceded by significant cassava root consumption. Differential diagnoses were excluded through a neuro-ophthalmic examination, blood tests and a brain MRI. All patients had visual field examination and OCT retinal nerve fiber layer (RNFL) analysis as well as an evaluation of their cassava consumption.
  
  
  RESULTS
  All patients had a bilateral optic nerve head atrophy or pallor predominantly located into the temporal sector. Visual field defects consisted of a central or cecocentral scotoma for all patients. RNFL showed lower values only in the temporal sector. Mean duration of cassava consumption prior to the appearance of visual symptoms was 22.7±11.2 years with a mean of 2.57±0.53 cassava-based meals per week. Cassava related optic neuropathy is possibly due to its high cyanide content and enabled by a specific amino-acid deficiency.
  
  
  CONCLUSIONS
  Cassava root chronic consumption is a rare, underappreciated cause of optic neuropathy and its exact mechanism is still uncertain.
authors.affiliation: Service d'ophtalmologie 3, Centre hospitalier national d'ophtalmologie des Quinze-Vingts, université de Versailles Saint-Quentin-en-Yvelines, 28, rue de Charenton, 75012 Paris, France. Electronic address: pierrezeboulon@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Zeboulon
authors.affiliation: Service urgences neuro-ophtalmologie, Fondation ophtalmologique Adolphe-de-Rothschild, 25, rue Manin, 75019 Paris, France; Centre hospitalier national d'ophtalmologie des Quinze-Vingts, 28, rue de Charenton, 75012 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Vignal-Clermont
authors.affiliation: Service d'ophtalmologie 3, Centre hospitalier national d'ophtalmologie des Quinze-Vingts, université de Versailles Saint-Quentin-en-Yvelines, 28, rue de Charenton, 75012 Paris, France; Service d'ophtalmologie, hôpital Ambroise-Paré, AP-HP, université de Versailles Saint-Quentin-en-Yvelines, 9, avenue Charles-De-Gaulle, 92100 Boulogne-Billancourt, France; Inserm, U968, université UPMC Paris VI, UMR S 968, Institut de la vision, CNRS, UMR 7210, 75012 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Baudouin
authors.affiliation: Service d'ophtalmologie 3, Centre hospitalier national d'ophtalmologie des Quinze-Vingts, université de Versailles Saint-Quentin-en-Yvelines, 28, rue de Charenton, 75012 Paris, France; Service d'ophtalmologie, hôpital Ambroise-Paré, AP-HP, université de Versailles Saint-Quentin-en-Yvelines, 9, avenue Charles-De-Gaulle, 92100 Boulogne-Billancourt, France; Inserm, U968, université UPMC Paris VI, UMR S 968, Institut de la vision, CNRS, UMR 7210, 75012 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Labbé
mesh_terms: D000293:Adolescent; D000328:Adult; D002163:Cameroon; D002648:Child; D007560:Cote d'Ivoire; D005247:Feeding Behavior / Q000208:ethnology; D005260:Female; D006801:Humans; D008270:Madagascar; D008297:Male; D002365:Manihot / Q000009:adverse effects*; D008875:Middle Aged; D009901:Optic Nerve Diseases / Q000209:etiology*; D012189:Retrospective Studies; D014037:Togo; D014786:Vision Disorders / Q000209:etiology*; D055815:Young Adult
keywords: Cassava; Cyanide; Cyanure; Manioc; Mitochondrial optic neuropathy; Neuropathie optique; Neuropathie optique mitochondriale; Optic neuropathy