title: Idiopathic chiasmal neuritis: clinical features and prognosis.
abstract: OBJECTIVE
  To describe the clinical features of idiopathic chiasmal neuritis in a large cohort of patients and to report their visual and neurologic outcomes.
  
  
  METHODS
  A retrospective medical record review of consecutive patients with chiasmal neuritis at a single institution. Patients with clinical or radiographic evidence of inflammation involving the intraorbital optic nerve and patients with a systemic inflammatory or neoplastic disorder were excluded.
  
  
  RESULTS
  Twenty patients were identified (14 female, 6 male; mean age, 37 years). Visual acuity at initial examination ranged from 20/15 to light perception. Progressive visual loss beyond 1 month was documented in 1 patient. Twelve of 15 patients who underwent magnetic resonance imaging demonstrated chiasmal enlargement and/or enhancement; 6 patients had 1 or more white matter lesions. Follow-up time ranged from 2 weeks to 22 years, with a mean of 5.7 years. The final median visual acuity was 20/20 (range, 20/15-20/50) and visual fields were normal or improved. Of 15 patients with a minimum follow-up interval of 1 year, 6 developed multiple sclerosis.
  
  
  CONCLUSIONS
  The demographic and clinical features of idiopathic chiasmal neuritis resemble those of idiopathic optic neuritis. Visual prognosis is excellent. In this series, 40% of patients subsequently developed multiple sclerosis.
authors.affiliation: Department of Neuro-Ophthalmology, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland. aki.kawasaki@fa2.ch
authors.forename: Aki
authors.initials: A
authors.lastname: Kawasaki
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Purvin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis; D009897:Optic Chiasm / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology; D009902:Optic Neuritis / Q000175:diagnosis*; D011379:Prognosis; D012189:Retrospective Studies; D012607:Scotoma / Q000175:diagnosis; D014792:Visual Acuity; D014794:Visual Fields