title: Stimulus parameters for multifocal pupillographic objective perimetry.
abstract: OBJECTIVE
  We compared the diagnostic power of 10 stimulus variants that assessed the visual fields of both eyes by recording pupillary responses to multifocal stimuli. The 10 variants comprised 6 initial tests, and 4 subsequent variants whose design was informed by the initial results.
  
  
  METHODS
  Two study groups containing 16 normal and 22 primary open angle glaucoma subjects, and 15 normal and 20 primary open angle glaucoma subjects had their diagnostic status verified by a slit-lamp investigation, applanation tonometry, 3 forms of perimetry, and Stratus OCT. Stereoscopically arranged displays presented multifocal stimulus arrays having 24 stimulus regions/eye within the central 60 degrees. Pupil responses were recorded by video cameras under infrared illumination. The 10 stimulus conditions varied in presentation rate, duration, stimulus luminance, and flicker rate. Stimuli were 4 minutes in duration, presented in 8 segments of 30 seconds. Up to 15% of the data of a segment could be lost owing to blinks and fixation losses without repeating the segment.
  
  
  RESULTS
  Each recording gave 96 direct and consensual responses/subject. The best performing stimulus method gave a sensitivity of 1.0 ± 0.0 (mean ± SE) for moderate and severe glaucomatous fields combined at a false positive rate of 0.05. Median signal to noise ratios for peak response amplitude expressed as t-statistics exceeded 4 for several variants.
  
  
  CONCLUSIONS
  Stimulus delivery rates of about 1 presentation/region/s and test luminance around 150 cd/m performed best diagnostically. Unlike automated perimetry, the mfPOP method provides information on response delays and afferent and efferent defects at each region of the visual field.
authors.affiliation: The Vision Centre, Centre for Visual Sciences, Research School of Biology, Australian National University, Canberra, Australia.
authors.forename: Andrew Charles
authors.initials: AC
authors.lastname: James
authors.forename: Maria
authors.initials: M
authors.lastname: Kolic
authors.forename: Suzanne Margaret
authors.initials: SM
authors.lastname: Bedford
authors.forename: Ted
authors.initials: T
authors.lastname: Maddess
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005189:False Positive Reactions; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008027:Light; D008297:Male; D008875:Middle Aged; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011680:Pupil / Q000502:physiology*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014741:Video Recording; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields