title: A pilot randomized controlled trial comparing effectiveness of prism glasses, visual search training and standard care in hemianopia.
abstract: OBJECTIVE
  Pilot trial to compare prism therapy and visual search training, for homonymous hemianopia, to standard care (information only).
  
  
  METHODS
  Prospective, multicentre, parallel, single-blind, three-arm RCT across fifteen UK acute stroke units.
  
  
  METHODS
  Stroke survivors with homonymous hemianopia.
  
  
  METHODS
  Arm a (Fresnel prisms) for minimum 2 hours, 5 days per week over 6 weeks. Arm b (visual search training) for minimum 30 minutes, 5 days per week over 6 weeks. Arm c (standard care-information only).
  
  
  METHODS
  Adult stroke survivors (>18 years), stable hemianopia, visual acuity better than 0.5 logMAR, refractive error within ±5 dioptres, ability to read/understand English and provide consent.
  
  
  RESULTS
  Primary outcomes were change in visual field area from baseline to 26 weeks and calculation of sample size for a definitive trial. Secondary measures included Rivermead Mobility Index, Visual Function Questionnaire 25/10, Nottingham Extended Activities of Daily Living, Euro Qual, Short Form-12 questionnaires and Radner reading ability. Measures were post-randomization at baseline and 6, 12 and 26 weeks.
  
  
  METHODS
  Randomization block lists stratified by site and partial/complete hemianopia.
  
  
  METHODS
  Allocations disclosed to patients. Primary outcome assessor blind to treatment allocation.
  
  
  RESULTS
  Eighty-seven patients were recruited: 27-Fresnel prisms, 30-visual search training and 30-standard care; 69% male; mean age 69 years (SD 12). At 26 weeks, full results for 24, 24 and 22 patients, respectively, were compared to baseline. Sample size calculation for a definitive trial determined as 269 participants per arm for a 200 degree2visual field area change at 90% power. Non-significant relative change in area of visual field was 5%, 8% and 3.5%, respectively, for the three groups. Visual Function Questionnaire responses improved significantly from baseline to 26 weeks with visual search training (60 [SD 19] to 68.4 [SD 20]) compared to Fresnel prisms (68.5 [SD 16.4] to 68.2 [18.4]: 7% difference) and standard care (63.7 [SD 19.4] to 59.8 [SD 22.7]: 10% difference), P=.05. Related adverse events were common with Fresnel prisms (69.2%; typically headaches).
  
  
  CONCLUSIONS
  No significant change occurred for area of visual field area across arms over follow-up. Visual search training had significant improvement in vision-related quality of life. Prism therapy produced adverse events in 69%. Visual search training results warrant further investigation.
authors.affiliation: Department of Health Services Research, University of Liverpool, Liverpool, UK.
authors.forename: F J
authors.initials: FJ
authors.lastname: Rowe
authors.affiliation: Department of Biostatistics, University of Liverpool, Liverpool, UK.
authors.forename: E J
authors.initials: EJ
authors.lastname: Conroy
authors.affiliation: Clinical Trials Research Unit, University of Liverpool, Liverpool, UK.
authors.forename: E
authors.initials: E
authors.lastname: Bedson
authors.affiliation: Clinical Trials Research Unit, University of Liverpool, Liverpool, UK.
authors.forename: E
authors.initials: E
authors.lastname: Cwiklinski
authors.affiliation: School of Health Sciences, University of Nottingham, Nottingham, UK.
authors.forename: A
authors.initials: A
authors.lastname: Drummond
authors.affiliation: Department of Biostatistics, University of Liverpool, Liverpool, UK.
authors.forename: M
authors.initials: M
authors.lastname: García-Fiñana
authors.affiliation: Department of Orthoptics, Salford Royal NHS Foundation Trust, Manchester, UK.
authors.forename: C
authors.initials: C
authors.lastname: Howard
authors.affiliation: Nursing, Midwifery and Allied Health Professions Research Unit, Glasgow Caledonian University, Glasgow, UK.
authors.forename: A
authors.initials: A
authors.lastname: Pollock
authors.affiliation: Department of Orthoptics, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
authors.forename: T
authors.initials: T
authors.lastname: Shipman
authors.affiliation: Department of Orthoptics, Oxford University Hospitals NHS Trust, Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: Dodridge
authors.affiliation: Department of Orthoptics, Oxford University Hospitals NHS Trust, Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: MacIntosh
authors.affiliation: Eye Clinic Impact Team, Royal National Institute for the Blind, Birmingham, UK.
authors.forename: S
authors.initials: S
authors.lastname: Johnson
authors.affiliation: Department of Ophthalmology, Aintree University Hospital NHS Foundation Trust, Liverpool, UK.
authors.forename: C
authors.initials: C
authors.lastname: Noonan
authors.affiliation: Department of Elderly Care, Warrington and Halton Hospitals NHS Foundation Trust, Warrington, UK.
authors.forename: G
authors.initials: G
authors.lastname: Barton
authors.affiliation: Division of Health and Social Care, King's College, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Sackley
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005139:Eyeglasses; D005260:Female; D006423:Hemianopsia / Q000209:etiology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011788:Quality of Life; D016037:Single-Blind Method; D020521:Stroke / Q000150:complications*; D000071939:Stroke Rehabilitation / Q000379:methods*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology
keywords: homonymous hemianopia; pilot trial; prism therapy; randomized controlled trial; standard care; stroke; visual search training