title: Medically unexplained visual loss in a specialist clinic: a retrospective case-control comparison.
abstract: OBJECTIVE
  To compare the clinical and demographic characteristics of adult patients with nonorganic or medically unexplained visual loss (MUVL) to those with other common conditions presenting to a neuro-ophthalmology clinic.
  
  
  METHODS
  Case-control design: a retrospective review of medical notes on a consecutive case series of 49 patients assessed at the King's College Hospital neuro-ophthalmology clinic with unexplained visual loss and matched with the next assessed patient identified from clinic records. Patients presented post-symptom onset with a mean clinical course of 30 months (SD=67 months) and standard clinical examination used to confirm diagnoses, alongside ancillary investigations if required.
  
  
  RESULTS
  Seventy-two percent (n=36) of MUVL patients were female. In comparison with patients with organic visual disorders, MUVL cases presented with significantly higher rates of bilateral (cf. unilateral) visual impairment (41%, n=20), premorbid psychiatric (27%, n=13) as well as functional (24%, n=12) diagnoses and psychotropic medication usage (22%, n=11). Medically unexplained cases were significantly more likely to report preceding psychological stress (n=9; 18%).
  
  
  CONCLUSIONS
  Medically unexplained visual impairment may be regarded as part of the spectrum of medically unexplained disorders seen in the general hospital setting. Research is needed to determine long-term outcomes and effective tailored interventions.
authors.affiliation: Section of Cognitive Neuropsychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 8AF, UK. Electronic address: eanna.oleary@kcl.ac.uk.
authors.forename: Éanna D
authors.initials: ÉD
authors.lastname: O'Leary
authors.affiliation: South London and Maudsley NHS Foundation Trust, London, UK.
authors.forename: Benjamin
authors.initials: B
authors.lastname: McNeillis
authors.affiliation: Laboratory for Behavioral Neurology and Imaging of Cognition, Fundamental Neurosciences Department, Geneva University, Switzerland.
authors.forename: Selma
authors.initials: S
authors.lastname: Aybek
authors.affiliation: Department of Ophthalmology, King's College Hospital, London SE5 9RS, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Riordan-Eva
authors.affiliation: Section of Cognitive Neuropsychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 8AF, UK.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: David
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013038:Specialization; D063189:Symptom Assessment; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult
keywords: Conversion disorder; Functional vision loss; Medically unexplained vision loss; Neuro-ophthalmology; Psychological; Visual reduction