title: Use of yoked prisms in patients with acquired brain injury: a retrospective analysis.
abstract: OBJECTIVE
  The purpose of this retrospective study was to determine the clinical practices for prescribing yoked prisms, as well as to assess related patient responses, in a sample of visually-symptomatic patients having acquired brain injury (ABI).
  
  
  METHODS
  The clinical records of individuals with acquired brain injury (ABI) that were assessed for yoked prisms were reviewed retrospectively. This query resulted in 60 patient records for analysis between January 2011 and December 2012. The following diagnostic groups were analysed: homonymous hemianopsia (HH)/homonymous quadranopsia, abnormal egocentric localization (AEL) and visual neglect.
  
  
  RESULTS
  HH/homonymous quadranopsia (58.3%) was the primary indication to prescribe yoked prisms, followed by visual neglect/unilateral spatial inattention (USI) (40.0%) and AEL (11.7%). The most common favourable patient responses were increased awareness of their blind visual field and improved gait, mobility and balance. The magnitude and direction of prisms prescribed were dependent upon the subjective responses in patients manifesting AEL. In contrast, base direction was dependent upon the direction of visual field loss in patients with HH/homonymous quadranopsia and visual neglect.
  
  
  CONCLUSIONS
  Two-thirds of the present sample population responded favourably to the yoked prisms. The results of the present study should prove useful to clinicians for the successful prescription of yoked prisms as a treatment modality in patients presenting with the above three diagnoses.
authors.affiliation: SUNY College of Optometry, Raymond J. Greenwald Rehabilitation Center (RJGRC) , New York, NY , USA.
authors.forename: Surbhi
authors.initials: S
authors.lastname: Bansal
authors.forename: Esther
authors.initials: E
authors.lastname: Han
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Ciuffreda
mesh_terms: D000221:Adaptation, Ocular; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D004867:Equipment Design; D005139:Eyeglasses; D005260:Female; D007839:Functional Laterality; D006423:Hemianopsia / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010469:Perceptual Distortion; D012189:Retrospective Studies; D016896:Treatment Outcome; D014787:Vision Tests; D014794:Visual Fields; D014796:Visual Perception
keywords: Abnormal egocentric localization (AEL); acquired brain injury (ABI); cerebral vascular accident (CVA); homonymous hemianopsia; visual neglect; yoked prisms