Effects of visual stimulation and visual training on children with visual impairment

In March 2006 the InSight foundation invited as to apply for a research grant
to study the effectiveness of visual stimulation for children with visual
impairment.
The invitation mentioned the following commission.
*Insight invites you to design a study on the effectiveness of visual
stimulation in children up till the age of 8 with ocular or cerebral visual
impairment with or without intellectual disabilities. The intervention should
consist of methods, materials, and visual tasks currently in use by early
intervention service providers. The intervention will be implemented according
to a standard protocol. Consensus on the
content of this 'standard intervention' could be determined by an expert
meeting."
With the help of several experts in the Netherlands a proposal for two studies
has been designed.

The goal is to study the effectiveness of visual stimulation in children up
till the age of 8 with ocular or cerebral visual impairment with or without
intellectual disabilities.
Since the commission explicitly stated that the intervention should consist of
methods, materials, and visual tasks currently in use by early intervention
service providers, one of the targets will be to first build consensus on a
standard intervention protocol.

As a result of this multi stage design the definitive choice of dependent
variables can only be made after the consensus meeting has been held.

Study 1:
The intervention will take place in an experimental control group design with a
pre-test (t0), one intermittent (t1), one post test (t2), and one follow up test
(t3). Tests will be performed by the researcher with intervals of four months.
Duration of the training will be 8 months. The children will be randomly
assigned to the treatment or control group. Children in both the treatment and
control group will receive normal early intervention services. Children in the
control
group will receive the common standard intervention with regard to visual
training but not an individualized visual training program, the latter is only
given to the children in the experimental group.

Study 2:
Training of several tasks to one individual and/or the same tasks to several
subjects will be given by a trained MSc-student after a comprehensive
assessment of the child*s competencies and relevant tasks.
Training procedures will be in accordance with Hall Lueck (2004), Hall and
Bailey (1989) and Hall Lueck, Dornbusch, & Hart (1999) and will be applied in a
nonconcurrent multiple baseline across variables and subjects design.

The first study will concern the effectiveness of visual stimulation in young
children in early intervention programs. The content of the intervention will
be based on previous studies of the Institute of Child Health of the Great
Ormond Street Hospital for Sick Children (Sonksen, Petrie, & Drew, 1991). This
program was chosen because it proved to be effective with children in the UK
and it seems to be suitable to current early intervention practices in the
Netherlands, mostly because several aspects of the intervention are already in
use. The exact content, assessment procedures, and as a consequence the number
and kind of dependent variables will be determined in a consensus meeting.
Professor Sonksen and collegues of the Institute of Child Health UCL has kindly
agreed to participate in this meeting and helped us to choose intervention and
variables for the study. In the meantime we have decided to apply the "record
of developing vision" and the accompanying activity cards from the
Developmental Journal for babies and children with visual impairment. This
program is not in us with any of the institutes in the Netherlands.


The second study concerns children 4 years and older. With these children
training can also be conducted at their schools, which may make it possible to
have daily training sessions. The procedures described by Hall Lueck, Dornbusch
and Hart (1999), Hall and Bailey (1989) and Hall Lueck (2004) will be used. In
this kind of training a topdown approach for choosing intervention effects is
used. Critical and relevant tasks given the child*s competencies, likes,
dislikes and needs, and the parent*s and teacher*s priorities are chosen.
Visual training is part of a larger intervention program and certainly not a
goal in itself. The effectiveness of this intervention will be the subject of
study 2.

Hall Lueck, A. (2004). Functional Vision, a practitioner's guide to evaluation
and intervention. New York: AFB Press.
Hall, A., & Bailey, I. L. (1989). A model for training vision functioning.
Journal of Visual Impairment & Blindness, 83, 390-396.
Hall Lueck, A., Dornbusch, H., & Hart, J. (1999). The effect of training on a
young child with cortical visual impairment: an exploratory study. Journal of
Visual Impairment & Blindness, 93, 778-793.
Sonksen PM, Petrie A, & Drew KJ. (1991). Promotion of visual development of
severely visually impaired babies: evaluation of a developmentally based
program. Developmental Medicine and Child Neurology. 33, 320-335.

Burden:
For child and one parent four home visits of 1 hour. Two orthoptic examinations
of 30 minutes.

Risk:
Time devoted to the intervention cannot be devoted to other activities.

Research justified:
Visual stimulation and visual training are commonly used in early intervention
programs for children with visual impairments. There is no standard
intervention and often intervention are applied that have no proven effect. As
we described in our article (Vervloed, M.P.J., Janssen, N. & Knoors, H. (2006).
Visual rehabilitation of children with visual impairment. Journal of
Developmental and Behavioral Pediatrics, 27, 6, 493-506.) there are
interventions that seem to be useful but the empirical evidence is still weak,
so no definite conclusions can be drawn regarding visual stimulation and
training.
The current study tries to enlarge this empirical evidence and to come up with
standards and protocols for rather arbitrarily applied intervention regarding
visual stimulation and training. Research by a population other than children
with visual impairments is useless, that is why the population as described
above will be studied.