title: Perceptual Relearning of Binocular Fusion and Stereoacuity After Brain Injury.
abstract: Brain lesions may disturb binocular fusion and stereopsis, leading to blurred vision, diplopia, and reduced binocular depth perception for which no evaluated treatment is currently available. Objective The study evaluated the effects of a novel binocular vision treatment designed to improve convergent fusional amplitude and stereoacuity in patients with stroke or traumatic brain injury (TBI). Methods Patients (20 in all: 11 with stroke, 9 with TBI) were tested in fusional convergence, stereoacuity, near/far visual acuity, accommodation, and subjective binocular reading time until diplopia emerged at 6 different time points. All participants were treated in a single subject baseline design, with 3 baseline assessments before treatment (pretherapy), an assessment immediately after a 6-week treatment period (posttherapy), and 2 follow-up tests 3 and 6 months after treatment. Patients received a novel fusion and dichoptic training using 3 different devices to slowly increase fusional and disparity angles. Results At pretherapy, the stroke and TBI groups showed severe impairments in convergent fusional range, stereoacuity, subjective reading duration, and partially in accommodation (only TBI group). After treatment, both groups showed considerable improvements in all these variables as well as slightly increased near visual acuity. No significant changes were observed during the pretherapy and follow-up periods, ruling out spontaneous recovery and demonstrating long-term stability of binocular treatment effects. Conclusions This proof-of-principle study indicates a substantial treatment-induced plasticity of the lesioned brain in the relearning of binocular fusion and stereovision, thus providing new, effective rehabilitation strategies to treat binocular vision deficits resulting from permanent visual cortical damage.
authors.affiliation: Saarland University, Saarbuecken, Germany International Research Training Group 1457 "Adaptive Minds," Saarbruecken, Germany annakatharina.schaadt@uni-saarland.de.
authors.forename: Anna-Katharina
authors.initials: AK
authors.lastname: Schaadt
authors.affiliation: Saarland University, Saarbuecken, Germany International Research Training Group 1457 "Adaptive Minds," Saarbruecken, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Schmidt
authors.affiliation: Saarland University, Saarbuecken, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Reinhart
authors.affiliation: Saarland University, Saarbuecken, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Adams
authors.affiliation: Saarland University, Saarbuecken, Germany.
authors.forename: Ruta
authors.initials: R
authors.lastname: Garbacenkaite
authors.affiliation: Saarland University, Saarbuecken, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Leonhardt
authors.affiliation: Saarland University, Saarbuecken, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Kuhn
authors.affiliation: Saarland University, Saarbuecken, Germany International Research Training Group 1457 "Adaptive Minds," Saarbruecken, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Kerkhoff
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000150:complications / Q000534:rehabilitation*; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000150:complications; D000071939:Stroke Rehabilitation / Q000379:methods*; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology / Q000534:rehabilitation*; D015348:Vision, Binocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
keywords: binocular vision; diplopia; reading; stereoacuity; stroke rehabilitation; traumatic brain injury; vision rehabilitation