title: Binocular treatment of amblyopia using videogames (BRAVO): study protocol for a randomised controlled trial.
abstract: Amblyopia is a common neurodevelopmental disorder of vision that is characterised by visual impairment in one eye and compromised binocular visual function. Existing evidence-based treatments for children include patching the nonamblyopic eye to encourage use of the amblyopic eye. Currently there are no widely accepted treatments available for adults with amblyopia. The aim of this trial is to assess the efficacy of a new binocular, videogame-based treatment for amblyopia in older children and adults. We hypothesise that binocular treatment will significantly improve amblyopic eye visual acuity relative to placebo treatment.
  
  
  
  The BRAVO study is a double-blind, randomised, placebo-controlled multicentre trial to assess the effectiveness of a novel videogame-based binocular treatment for amblyopia. One hundred and eight participants aged 7 years or older with anisometropic and/or strabismic amblyopia (defined as ≥0.2 LogMAR interocular visual acuity difference, ≥0.3 LogMAR amblyopic eye visual acuity and no ocular disease) will be recruited via ophthalmologists, optometrists, clinical record searches and public advertisements at five sites in New Zealand, Canada, Hong Kong and Australia. Eligible participants will be randomised by computer in a 1:1 ratio, with stratification by age group: 7-12, 13-17 and 18 years and older. Participants will be randomised to receive 6 weeks of active or placebo home-based binocular treatment. Treatment will be in the form of a modified interactive falling-blocks game, implemented on a 5th generation iPod touch device viewed through red/green anaglyphic glasses. Participants and those assessing outcomes will be blinded to group assignment. The primary outcome is the change in best-corrected distance visual acuity in the amblyopic eye from baseline to 6 weeks post randomisation. Secondary outcomes include distance and near visual acuity, stereopsis, interocular suppression, angle of strabismus (where applicable) measured at baseline, 3, 6, 12 and 24 weeks post randomisation. Treatment compliance and acceptability will also be assessed along with quality of life for adult participants.
  
  
  
  The BRAVO study is the first randomised controlled trial of a home-based videogame treatment for older children and adults with amblyopia. The results will indicate whether a binocular approach to amblyopia treatment conducted at home is effective for patients aged 7 years or older.
  
  
  
  This trial was registered in Australia and New Zealand Clinical Trials Registry ( ACTRN12613001004752 ) on 10 September 2013.
authors.affiliation: School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand.
authors.forename: Cindy X
authors.initials: CX
authors.lastname: Guo
authors.affiliation: School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada.
authors.forename: Raiju J
authors.initials: RJ
authors.lastname: Babu
authors.affiliation: School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Black
authors.affiliation: School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada.
authors.forename: William R
authors.initials: WR
authors.lastname: Bobier
authors.affiliation: School of Optometry, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong, SAR, China.
authors.forename: Carly S Y
authors.initials: CS
authors.lastname: Lam
authors.affiliation: Department of Ophthalmology, Starship Children's Hospital, Auckland, New Zealand.
authors.forename: Shuan
authors.initials: S
authors.lastname: Dai
authors.affiliation: School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand.
authors.forename: Tina Y
authors.initials: TY
authors.lastname: Gao
authors.affiliation: Department of Ophthalmology, McGill Vision Research, McGill University, Montreal, QC, Canada.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Hess
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Michelle
authors.initials: M
authors.lastname: Jenkins
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Yannan
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Surgery, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital; Ophthalmology, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Lionel
authors.initials: L
authors.lastname: Kowal
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Varsha
authors.initials: V
authors.lastname: Parag
authors.affiliation: School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand.
authors.forename: Jayshree
authors.initials: J
authors.lastname: South
authors.affiliation: Department of Surgery, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital; Ophthalmology, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Sandra Elfride
authors.initials: SE
authors.lastname: Staffieri
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Natalie
authors.initials: N
authors.lastname: Walker
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Angela
authors.initials: A
authors.lastname: Wadham
authors.affiliation: School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand. ben.thompson@uwaterloo.ca.|School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada. ben.thompson@uwaterloo.ca.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Thompson
mesh_terms: D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000628:therapy*; D002648:Child; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D006801:Humans; D018910:Video Games; D055815:Young Adult
keywords: Amblyopia; Binocular vision; Perceptual learning; Plasticity; Suppression; Videogame