title: Diagnostic sensitivity/specificity of preattentive vision tests in glaucoma.
abstract: OBJECTIVE
  Damage to the nerve fiber layer or visual pathway might be expected to reduce the efficiency with which the visual system performs analysis of the ever-changing field of vision. The purpose of this article is to provide a further analysis of previously reported data (Loughman J, Davison P, Flitcroft I, Br J Ophthalmol 2007;91:1493-98.) to: (i) determine the sensitivity and specificity of a test of preattentive vision for glaucoma detection and (ii) provide a cutoff performance level that would serve to distinguish glaucoma in early cases.
  
  
  METHODS
  Three groups of observers (glaucoma, suspects, and normals) were examined, using computer-generated flicker, orientation, and vertical displacement targets to assess preattentive visual search (PAVS) efficiency. The task required rapid and accurate localization of a singularity embedded in a field of 119 homogenous distractors on either left or right hand side of a computer monitor. All subjects also completed a choice reaction time task.
  
  
  RESULTS
  Receiver operating characteristic curve analysis demonstrates consistently high diagnostic sensitivity and specificity values (significantly above 90% for all tasks) using the raw PAVS data and also for a novel perceptual search index (which improves the diagnostic capacity of the test). Optimal performance cutoff values for each task were also computed.
  
  
  CONCLUSIONS
  A test of PAVS efficiency demonstrates high sensitivity and specificity to early glaucoma. Analysis incorporating the perceptual search index confirms the high diagnostic capacity of the test.
authors.affiliation: Optometry Department, Dublin Institute of Technology, Republic of Ireland. james.loughman@dit.ie
authors.forename: James
authors.initials: J
authors.lastname: Loughman
authors.forename: Peter
authors.initials: P
authors.lastname: Davison
authors.forename: Ian
authors.initials: I
authors.lastname: Flitcroft
mesh_terms: D005425:Flicker Fusion / Q000502:physiology*; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D009798:Ocular Hypertension / Q000175:diagnosis / Q000503:physiopathology; D009949:Orientation; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D014787:Vision Tests; D014794:Visual Fields