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Optometric Management
of Childhood Visual
Problems
do is not helpful to a practitioner
confronted
with
a
child
patient.
Instead the practitioner must consider
many other aspects, and in this respect
must consider each individual child
on his/her own merits and risk factors.
The second article of this series
(see OT February 24, 2012) described
the usual progress of refractive errors
YOUNG CHILDREN’S VISION PART 5 C-18925 O/D
in early childhood, the process of
18/05/12 CET
emmetropisation, and that refractive
Dr Margaret Woodhouse, BSc (Hons), PhD, MCOptom
errors which do not emmetropise place
Previous articles in this series have discussed normal visual development in
a child at risk of strabismus and/or
amblyopia. A reasonable procedure
young children and ways of successfully testing a young child, including advice
for a very young child would be to
about adapting test techniques to optimise results obtained.This current article
monitor the refractive error during the
discusses the significance of the test results and what the practitioner should
expected emmetropisation period and
consider when deciding whether and what to prescribe for the child patient.
consider prescribing for an error that
is not reducing. An exception to this
would be a child with disabilities such
refractive error he or
as Down’s syndrome or cerebral palsy,
she would consider
in which emmetropisation does not
prescribing for a non-
take place. A correction at an earlier
strabismic
age is warranted in such situations.
child
different ages. Such a
At any age, a practitioner would
survey might provide
consider prescribing for an extreme
useful
error
guidelines
outside
the
expected
for
practitioners.
The
results
are
largely complete by 2-3 years, so at
reproduced in Table
this stage any refractive error is likely
1. What is somewhat
to remain stable and the practitioner
surprising is the very
must determine the significance of the
wide variation in the
error for the child e.g. with regard to
level
of
performance and comfort at school.
error
that
warrants
Refractive errors
lying
distribution.
refractive
optometrists
Figure 1
Robert enjoying the experience of prism bars during assessment of
binocular status (fusional reserves) (photo courtesy Mike O’Carroll)
of
hospital
believe
correction.
Emmetropisation
is
Strabismus, amblyopia and
anisometropia
Considering
the
The
prescription
for
prescribe for a child with strabismus
in
or amblyopia, irrespective of the age.
hypermetropia
usual
practice
would
be
to
a 1 year old, the
In a convergent strabismus with an
minimum and maximum values show
accommodative element, the full plus
that at least one UK optometrist would
prescription is usually given. Many
In 2008 Jane Farbrother published the
prescribe +2.00D for a 1 year old,
practitioners would feel it appropriate
results of her survey of prescribing
while at least one other optometrist
to refer a strabismic child to the
practice
would leave a child with 14.75D of
hospital eye service (HES), but they
hypermetropia
would be advised to offer spectacle
among
optometrists.1
Each
UK
hospital
optometrist
was asked to indicate what level of
uncorrected.
Thus,
discovering what other optometrists
correction
immediately,
especially
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Type of Refractive Error
Age of Child
1 year
3 years
5 years
Mean (D)
-3.47
-1.87
-0.98
Min – Max (D)
-0.50 -10.00
-0.25 -10.00
-0.25 -3.00
Mean (D)
+5.02
+3.40
+2.54
Min – Max (D)
2.00 – 15.00
1.00 – 6.00
1.00 – 5.00
Mean (D)
2.63
1.60
1.13
Min – Max (D)
1.00 – 8.00
0.25 – 4.00
0.25 – 2.50
1.38
1.10
0.25 – 3.00
0.25 – 3.00
Isometropia
Hypermetropia
Astigmatism
Anisometropia
Hypermetropia
Mean (D)
2.08
Table
1
Current prescribing practice by hospital optometrists for a non-strabismic child1
Min – Max (D)
0.25 – 8.00
in an accommodative case, so that
persistent
the
than to put into practice; the third
some benefit can be had in the interim
two eyes of 1.00D or more should be
article of this series (see OT March
period whilst the child is waiting to
considered abnormal. The practitioner
23 2012) discussed the difficulty of
receive an appointment at the hospital.
should therefore consider prescribing
a young child wearing a trial frame
Recent studies have shown that
the difference, to prevent amblyopia.
and how this can sometimes make it
refractive correction alone (without
However, the practitioner should take
difficult to record a reliable corrected
occlusion therapy) can successfully
all the other factors into account in
acuity, if the child is distracted by the
treat amblyopia in a proportion of
determining the absolute correction.
discomfort and restricted field from
cases,
recommendation
For example, if a child’s refractive
the frame. Consider keeping to hand
now is to provide spectacles for the
error is R +1.50, L+4.00, then it may be
a number of comfortable spectacle
child to wear constantly for around 18
appropriate to prescribe the full plus, or
frames that have been glazed with
weeks before considering occlusion
a reduced/modified correction such as
different refractive powers. These can
therapy. As with strabismus, even
R+0.50, L+3.00 might be more suitable.
be very useful in measuring visual
if
In
difference
acuity with a more comfortable frame
between the eyes must be incorporated.
(albeit with the nearest correction),
a
2-4
and
the
practitioner
refers
the
child
to the HES, a spectacle correction
every
difference
case
the
between
full
but also provides an indication as to
should be given so that refractive
treatment
begins
immediately.
Visual acuity
a child’s reaction to spectacle wear.
A useful guideline would be to correct
Uncorrected myopia will inevitably
OT February 24, 2012) also described
any refractive error that is reducing
reduce distance visual acuity. However,
the rarity of anisometropia, and a
visual acuity. This is easier to say
remember that young children have
The second article of this series (see
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Myopia
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only limited interest in distance
instructions given for spectacle
viewing. Most learning and
wear. For example, a child at
play activities take place at
risk of convergent strabismus
near (including watching TV!)
will probably be advised full-
and a child is not impaired
time wear of a plus prescription.
by low myopia when very
A myopic child with a large
young. Correction might wait
exophoria at near will probably
until the child begins to take
benefit from spectacle wear for
more interest at distance, and
near work as well as distance.
the
take
Children with heterophoria at
parental advice on this. Once
risk of decompensating should
a child is at school, distance
also undergo a full binocular
activities such as board work
vision
become
prism cover test for fusional
practitioner
might
important,
and
a
correction would be warranted.
Figure 2
Daniel is choosing a frame
investigation
reserves),
the
The effect of uncorrected
risk
so
of
as
the
to
(eg,
evaluate
heterophoria
becoming a manifest strabismus.
hypermetropia is more difficult to
different plus lenses in place; again,
predict and the practitioner should
a range of glazed frames can be
not assume normal distance visual
useful to replace the trial frame. The
Encouraging spectacle wear
acuity.
near
minimum plus that renders a normal
Many parents of young children express
acuity should be paramount, along
accommodative response might be a
concern about how their child will
with
accommodation,
useful starting prescription to consider.
react to wearing spectacles, and some
in determining when to prescribe.
As described in the second article of
have genuine struggles with their child.
For prevalence studies, astigmatism
this series (see OT February 24, 2012),
Very few children will tolerate full-
is usually considered significant when
children with disabilities are at high risk
time wear of spectacles from the start,
1.00DS or more. However, unless
of accommodative deficits. These have
so even if full-time wear is the ultimate
prescribing a spherical component,
been demonstrated in children with
aim, it is unrealistic to expect it at the
there is little argument for prescribing
Down’s syndrome5 and cerebral palsy6
outset, and failure will inevitably result
for astigmatism at this level and a slightly
when distance refractive errors are fully
in parents feeling inadequate. However,
higher criterion of 1.50 or 2.00DS seems
corrected, and in children with Down’s
children do adapt and the practitioner
more sensible. Again, practitioners
syndrome the accommodative lag is
should give parents appropriate advice.
should
other
unaffected by single vision spectacles
The first step is, of course, dispensing
factors, such as the risk of amblyopia
for hypermetropia.7 However, in both
comfortable and stable frames (Figure
in cases of unilateral astigmatism.
conditions,
from
2), as no child will wear frames that
spectacles8-10 and
rub or slip. The child should also be
practitioners should be prepared to
encouraged to select a frame that they
prescribe such corrections for any child
like, so that they are more likely to
with a difficulty in accommodation.
wear the spectacles. The next article
A
measurement
recording
also
bear
in
of
mind
children
bifocal/multifocal
Accommodation
Measurement of accommodation (see
Article 3 of this series, OT March
benefit
in this series will address dispensing
23, 2012) is essential in deciding on
whether hypermetropic prescriptions
Binocular vision
should be prescribed especially in
The observed or predicted effect of
children who cannot yet carry out near
a spectacle prescription on a child’s
reassure parents that their child will
acuity measurements and/or describe
binocular vision status should also
accept spectacle wear, but will do
symptoms. If a child demonstrates
influence a practitioner’s decision on
so in their own time. Some children
an accommodative lag then he or
what to prescribe. Family history will
take weeks or even months to tolerate
she should be offered a prescription.
contribute to the assessment of a child’s
spectacles.
The amount of plus prescribed can
risk of developing strabismus. Binocular
spectacle lenses change how the world
be decided by assessing the lag with
vision status will also influence the
looks to a child, and some children
for
children
Secondly,
in
greater
practitioners
Remind
detail.
should
parents
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that
resist new experiences. The lenses
spectacles, take them off for him or her,
when
also magnify (plus) or minify (minus)
(so that there is no compulsion) and
Practitioners should take all visual
and have distortions at the edges;
stop the activity. Repeat the following
functions into account and prescribe on
all very good reasons for children
day, gradually lengthening the time of
the grounds of visual acuity, binocular
to reject them. If this seems to be
the activity or introducing a second
vision,
the problem, the practitioner could
activity. Do not turn the process into a
the risks posed of deficits, keeping
consider a reduced correction to aid
battle; if the child snatches the glasses
in
mind
this adaptation process, as long as this
off and throws them, do not react, but
of
visual
is compatible with binocular status
simply take a long time to pick them
and is consistent with the initial
up and put them away (thus removing
About the Author
reason for prescribing, for the first pair.
attention). Any visible reaction on the
Maggie Woodhouse is Senior Lecturer
Parents should be advised to choose
part of the parent will encourage the
at the School of Optometry & Vision
encourage
child to throw the glasses again – after all,
Sciences, Cardiff University, where she
their child to wear their spectacles,
it’s a great way to annoy mum and dad!
specialises in paediatric optometry.
favourite
corresponding
activity
to
to
when
they
will
Before too long, the child will
She
runs
visual
the
the
functions
normal
functions
needed.
and
development
in
Special
childhood.
Assessment
appreciate
a hypermetropic child or watching
will
want
television for a myope, and when
what
we
the
interests are visual development in
the child has an adult’s undivided
child’s pace, not the practitioner’s.
children with Down’s syndrome and the
to
are
spectacles
near
is
have benefit eg, reading a book for
attention. Place spectacles on the child
the
prescription
wear
them.
aiming
for,
and
Clinic, which caters for patients of all
That’s
ages with disabilities. Her particular
at
impact of visual defects on education.
and start the activity, helping the child
Conclusion
to appreciate how much clearer or easier
There are no guidelines for prescribing
References
the task is. Make the activity short (the
for children; the practitioner must
See www.optometry.co.uk/clinical.
younger the child, the shorter the time).
decide for him or herself, and of
Click on the article title and then on
If the child becomes frustrated with the
course, in discussion with the parents,
‘references’ to download.
Module questions Course code: C-18925 O/D
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1. When considering prescribing for a 3-year-old hypermetropic
non-strabismic child, the average hospital optometrist would:
a) Prescribe +3.00D
b) Prescribe +4.00D
c) Prescribe +14.75D
d) Prescribe +2.00D
2. When managing a child with Down’s syndrome, the practitioner
should:
a) Be prepared to prescribe bifocal spectacles
b) Fully correct hypermetropia in all cases
c) Monitor until the end of the emmetropisation period
d) Measure and record accommodative accuracy
3. If a child has refractive amblyopia, the recommended first step in
management is:
a) Referral to the Hospital Eye Service
b) Prescribe spectacles for constant wear for 8 weeks
c) Prescribe spectacles for constant wear for 4-5 months
d) Begin immediate full-time occlusion therapy of the amblyopic eye
4. If a child requires a myopic correction, the following apply EXCEPT:
a) Correction may not benefit a young child
b) Correction will reduce convergence in esophoria
c) Distance acuity will improve
d) Objects will appear smaller
5. If a child has a hypermetropic refractive error, the following apply
EXCEPT:
a) The plus power required can be determined by dynamic retinoscopy
b) It may be valuable to prescribe if there is a family history of strabismus
c) Distance visual acuity will reduce; spectacles are for close work only
d) All anisometropia over 0.75D should be corrected
6. If a child requires spectacles for full-time wear, you should advise
the parents:
a) To choose a cheap frame as it may get broken
b) To encourage full-time wear from the first day
c) That the child’s lazy eye may go blind if the spectacles are not worn
d) That lenses present the child with an unfamiliar world
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a