Article

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.
CI - (c) The Author(s) 2013.

Langue : ANGLAIS