The Effect of Visual Impairment on Quality of Life of Children aged 3-16

Abstract

It is well known that visual impairment (VI) has a detrimental effect on Quality of Life (QoL) in adults. Little is known about the effects of VI in childhood.
To evaluate the effects of VI on QoL of children. To the authors' knowledge, this is the first study containing a comparison arm for children with VI.
QoL in children with VI (n=24, age 10.13±2.89, 18 male, 6 female) was compared with an age-matched comparison group (n=24, age 9.83±2.81, 18 male, 6 female) using the Low Vision Quality of Life Questionnaire. Factors (distance and near visual acuity and age) that could be used as predictors of QoL were assessed. These were measured with standard clinical tests.
Children with VI had significantly lower QoL scores than the comparison group (p<0.001), resulting in a 35.6% reduction in total QoL score. QoL scores in children with VI were correlated with distance and near visual acuity (p<0.05). 38% of the variance could be predicted by these factors and age.
Consideration of the effects of this reduced QoL must be made. Further studies are needed to establish the benefit to QoL of different habilitation strategies.

Full text

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The Effect of Visual Impairment on Quality of Life of Children aged 3-16
years
Rasmeet K Chadha¹ Ahalya Subramanian ²
¹Optometry Department, Oxford Eye Hospital, Oxford, England
² Department of Optometry and Vision Sciences, City University, London,
England
Background: It is well known that Visual impairment (VI) has a detrimental
effect on Quality of Life (QoL) in adults. Little is known about the effects of VI
in childhood.
Aims: To evaluate the effects of VI on QoL of children.
To the authors’ knowledge, this is the first study containing a comparison arm
for children with VI.
Methods: QoL in children with VI (n =24, age 10.13 ± 2.89, 18 male, 6
female) was compared to an age matched comparison group (n =24, age 9.83
± 2.81, 18 male, 6 female) using the Low Vision Quality of Life Questionnaire.
Factors (distance and near visual acuity and age) that could be used as
predictors of QoL were assessed. These were measured with standard
clinical tests.
Results: Children with VI had significantly lower QoL scores than the
comparison group (P < 0.001), resulting in a 35.6% reduction in total QoL
score.
QoL scores in children with VI were correlated with distance and near visual
acuity (P < 0.05). 38% of the variance could be predicted by these factors and
age.
Conclusions: Consideration of the effects of this reduced QoL must be
made. Further studies are needed to establish the benefit to QoL of different
habilitation strategies.

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INTRODUCTION
Visual impairment (VI) in childhood has life long implications for both the child
and their family. Indeed it affects the child’s development, education, and the
care given by families and professionals. It also shapes the adult the child will
become, affecting employment and social prospects.[1] Although less
common than VI in adulthood [2] the number of ‘blind years’ experienced by
these children in their lifetime is of particular significance.[3] The enduring
needs of these children, their parents and families should be considered from
a lifelong perspective. [4]
There are no consistent national estimates on the prevalence of childhood VI
as the methods to record prevalence vary between surveys. [5] Certification in
England, completed on a Certificate of Visual Impairment (CVI), is as Sight
Impaired (Partially sighted) or Severely Sight Impaired, (Blind). Using the
most recent registration data from 2006 there were approximately 3825
children (0-17years) registered severely sight impaired and 4800 children
registered sight impaired [6].The aetiology of childhood VI in the UK is
changing, demonstrating a decrease in isolated VI and increase in VI with co-
existing neurological disability.[7]
It is important to appreciate that the impact of childhood VI is different to VI in
adulthood. It differs not only in terms of age of onset and cause of impairment
but perhaps more importantly in terms of the lifetime of disability these
children endure and the impact that their VI has on family, friends and
relationships as they grow up. In addition childhood VI poses particular, and

3
distinct, assessment and management challenges to professionals.[3]
Children with VI can not be considered to be scaled down adults and
therefore, the outcomes of studies relating to Quality of Life (QoL) in adults
with VI can not be extended to relate to childhood VI. Further more whilst
adult standards exist for low vision services [8,9] it is impossible and
inappropriate to benchmark paediatric services against these.
It has been estimated that 80% of education is provided through sight. [10]
The majority of children with VI in the UK are educated in the mainstream
setting alongside normally sighted peers [11] and are encouraged to be
integral members of society. It is therefore important to look at their QoL
relative to their sighted peers.
There are very few studies on QoL in children with VI.[12-14] Whilst providing
valuable information in a field where very little is currently known, they have
been limited by the lack of availability of child specific vision related QoL
questionnaires at the time of their study. The studies to date have
concentrated on comparing QoL in children with VI to children with other
disease. They have not compared QoL of children with VI to normally sighted
children without any disability.
There have been some recent developments in the design of children’s vision
QoL questionnaires: the Children’s Visual Function Questionnaire (CVFQ)
[15], LV Prasad Functional Vision Questionnaire (LVP-FVQ) [16] and The
Impact of Visual Impairment on Children (IVI_C) [17].The IVI_C was
unpublished at the time of this study and to the author’s knowledge is not

4
available for general use. The LVP-FVQ and CVFQ were inappropriate for
use in this study. The LVP-FVQ was designed in India as a screening tool for
developing countries and so the specificity of the questions to the given
cultural group made it difficult to use in the western population. The CVFQ
was designed for use by proxys for children up to the age of 7 and has been
shown to demonstrate meaningful differences in children with varying levels of
VI. [18] The children in the current study were between the ages of 3-16.
AIMS
To our knowledge, this is the first study to contain a comparison arm for
children with VI in the UK allowing us to relate the effects of their impairment
to the society in which they live by asking 2 questions:
1. Is there a statistical difference in QoL in children with VI compared to an
age matched comparison group?
2. Are there any demographic or clinical factors that can be used as correlates
or predictors of QoL for children with VI?
MATERIALS AND METHODS
Participants
The children were divided into 2 groups:

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Children with VI: Were regular attendees of the paediatric low vision clinic at
Oxford Eye Hospital and had been given a diagnosis/working diagnosis of the
aetiology of their VI.
These children received comprehensive visual rehabilitation (now often
referred to, and more correctly, as habilitation) and had access to ophthalmic
and community support provided by a complement of multidisciplinary
professionals working together, centered around the needs of the child and
family. Services included investigative tests, formal diagnosis (where
possible), emotional support, genetic counselling, low vision assessment,
mobility training, support at home and in school.
Age matched comparison group: Attended either the paediatric orthoptic (for
investigation and management of a binocular vision anomaly e.g. unilateral
amblyopia) or colour vision (for investigation of a suspected congenital colour
vision defect) clinic at Oxford Eye Hospital. Thus they were matched for
hospital attendance but had no known visual disability. They were
asymptomatic and not undergoing any form of non optical treatment (e.g.
patching or surgery) at the time of participation.
Eligibility criteria
Children with VI had visual acuity (VA) in their better eye of LogMAR 0.30.
Children in the age matched comparison group had VA in their better eye
LogMAR 0.00.

6
In both groups, children with a significant non visual physical or learning
difficulty were excluded.
Outcomes
The outcomes followed the tenets of the declaration of Helsinki and informed
consent was obtained for all. NHS ethics approval was granted in December
2006.
The Low Vision Quality of Life Questionnaire (LVQOL) [19] was chosen as the
outcome measure for this study. The maximum score is 125 with a higher
value reflecting a better QoL score. Of the available vision specific QoL
questionnaires (excluding the paediatric versions for reasons described
above) it was most suited to use with children (there are no questions that
related solely to an adult population) and was quick to complete (improving
response rates).
QoL scores of children in both groups were compared and correlates and
predictors of QoL were investigated for children with VI. Parents were asked
to complete the questionnaire but to involve their child to a level appropriate
for the individual child. Hence the questionnaire was primarily completed by
proxy.

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Statistical Analysis
Sample sizes were calculated using a web based tool
(http://home.clara.net/sisa/sampshlp.htm). Assuming the data to be normally
distributed and have means and variances attributed to the data collected
from patients with VI and the age matched comparison group used to trial the
LVQOL [19] the minimum sample size in each group to give 90% power to
detect a difference between the groups at a confidence level of P= 0.001 for
an independent t test was 25 and using P = 0.05 with a power of 90% the
sample size was 13. Using the values for means and standard deviations
obtained in this study the sample size required to give a power of 90% at a
confidence level of P = 0.001 is 12. Therefore, the sample size in the study (n
= 24) allows for conclusions with a power of 90% and a confidence level of P
= 0.001 to be made.
Correlation and multiple linear regression were used to look at the relationship
between QoL and factors of visual function in children with VI.
Data for children with VI was compared to children in the age matched
comparison group using an independent samples t test.
RESULTS
Patient demographics

8
Table 1 outlines the demographics of the 2 groups whilst table 2 outlines the
diagnosis of the children with VI. There was a 67% response rate for the
children with VI (24/36).
Group
Age
(SD)
Sex
Distance VA
(LogMAR)
Near VA
(LogMAR)
Children with VI
(n=
24)
10.13 ± 2.89
18M
6F
0.59 ± 0.28
0.80 ± 3.27
Age matched
comparison group (n=
24)
9.83 ± 2.81
18M
6 F
At least 0.00
Not measured
Table 1: Demographics of participants
Description
of eye condition
Number of children
Oculocutaneous albinism
4
Dislocation of lens
1
Retinal detachment with retinal
break
1
Hereditary retinal dystrophy
2
Other retinal disorders in
diseases classified elsewhere (
in this case Battens Disease)
1
Optic Atrophy
3
Nystagmus
8
Retinopathy of prematurity and
Nystagmus
2
Nystagmus and visual field
defect (in this case
homonymous hemianopia)
1
Congenital lens malformations
1
Table 2: Ophthalmic diagnoses in children with VI
Quality of life scores, demographic factors and factors of visual function
as correlates or predictors of QoL
Total QoL scores and all sub scale scores in children with VI were statistically
lower than in the age matched comparison group (Table 3 and figure 1).

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Subscale
Qo
L
score
children with
VI
Qo
L
score
age
matched
comparison
group
Significance
Distance
vision,
mobility and lighting
(max 60)
35.92 ± 12.93
54.98 ± 9.37
P
< 0.001
Adjustment
(max 20)
14.98 ± 3.61
18.48 ± 2.40
P
< 0.001
Reading & fine work
(max 25)
15.19 ± 6.76
23.17 ± 3.14
P
< 0.001
Activities of daily
living (max 20)
14.32 ± 4.34
19.33 ± 1.69
P
< 0.001
Total LV
QOL
score
(max 125)
80.50 ± 25.21
116.00 ± 12.68
P
< 0.001
Table 3: QoL scores for children with VI and age matched comparison group
Figure 1: QoL Number of responses with a given QoL score:
Whilst not statistically significant, older children with VI (n = 15 age 11-16),
had poorer total QoL scores than their younger counterparts (n = 9 age 5-10)
(76.30 ± 27.28 vs. 87.50 ± 20.88). The reverse is true when looking at the age
matched comparison group, where the older children (n = 10) had better total
0
2
4
6
8
10
12
14
16
10-20
21-30
31-40
41-50
51-60
61-70
71-80
81-90
91-100
100-110
110-120
121-130
Total QOL s core
Number of responses
Children with VI
Age matched compa rison
group

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QoL scores than their younger counterparts (n = 14) (118.05 ± 10.23 vs.
114.54 ± 14.37).
Female parents completing the questionnaires (in children with VI (n = 17)
and the age matched comparison group (n = 18)) reported higher total QoL
scores than male parents. This was statistically significant in the age matched
comparison group (118.72 ± 9.09 vs. 107.83 ± 18.76 P < 0.001).
Total QoL for children with VI was significantly correlated with distance
LogMAR VA (Spearman’s rho= -0.44) (P < 0.05) and near LogMAR VA
(Spearman’s rho=-0.52) (P < 0.01). Multiple regression of these factors
against total QoL score revealed that 26.9% of the variability could be
attributed to these variables. 38% of the variability in total QoL score could be
attributed to distance LogMAR VA, near LogMAR VA and age. When
assessed individually: distance LogMAR VA contributed 24.6% to the
variance, near LogMAR VA 23.0% and age 0.27%. Age was included in the
regression equation as there was an interesting trend relating to age and QoL
(reported above). There were unfortunately insufficient numbers (due to
unequal numbers in the groups) to look for correlations between stability of
the eye condition, age at diagnosis and field loss with total QoL scores.
DISCUSSION
In this study there was no control for the proxy effect. This is an accepted
limitation. It has been reported [20, 21] that parents of children with serious
disability usually report a poorer QoL for their child than the child would report

11
themselves and vice versa for healthy children. It is plausible that this study
has served to increase the differences in scores between the groups. Future
studies will need to control for this proxy effect by ensuring that they obtain
only the child’s views or separate the views of all contributors, being clear
whether the views are their own or proxy for the child. Moreover, since we
found that female proxys tend to report higher QoL than their male
counterparts consideration as to the sex of the proxy should be made.
Cochrane et al [17] recently demonstrated that the concerns expressed by
support providers are different to that expressed by the child. Ensuring that all
views are considered is of paramount importance when dealing with childhood
VI to ensure that a complete assessment of the child’s QoL is made.[22]
Having a specifically designed, age appropriate questionnaire that the
children can complete independently such as the recently developed Cardiff
Visual Ability Questionnaire (CVAQC) [23] or the IVI_C [17] will help.
Limitations aside, our results highlight some important points for to be
considered by all those supporting children with VI.
The finding that the total and subscale QoL scores in children with VI were
significantly lower (P< 0.001) than in the age matched comparison group
requires careful consideration. When compared to the maximum QoL score of
125, children with VI demonstrated a 35.6% reduction and the age matched
comparison group a 7.2% reduction.
Although the LVQOL was not designed specifically for the paediatric
population, the significant difference between children with VI and the age

12
matched comparison group serves to confirm the ability of the LVQOL to
differentiate between these groups.
Why do children with VI have lower QoL scores than children in the age
matched comparison group despite having undergone comprehensive
habilitation? At this stage we can only postulate on the reasons for this as
there have been no other studies looking at QoL in children with VI compared
to an age matched comparison group. However, Wolffsohn [19] also found
that their adult patients, post rehabilitation, had lower QoL scores than those
with normal vision.
Habilitation may be of great benefit to the child with VI but can not fully restore
QoL. These children throughout their lifetimes will continue to need to make
modifications to their environment to improve their functioning but these are
unlikely to fully restore visual functioning and so will have reduced QoL
compared to their sighted peers. Future studies that include a control group
for the type of habilitation, will help us establish whether habilitation can be
tailored to meet individual needs to improve individual QoL scores.
The effect of age on QoL in childhood VI is very important. In this study older
children with VI had poorer total QoL scores than their younger counterparts
and there was no significant difference in VA in either group. With increasing
age, even when VA remains essentially unchanged, the demands made upon
the visual system increase (e.g. the requirement to read smaller print, to drive
etc). It could be postulated that an increasing inability to meet these demands

13
would result in a poorer QoL. Future studies looking at QoL and childhood VI
must take into consideration the effect of age on QoL.
It would be helpful, in a clinical setting, to be able to identify the test results
that most accurately represent QoL so as to alert the clinician to patients with
significantly reduced QoL.
In the present study distance LogMAR and near LogMAR VA were
significantly correlated with total QoL (P < 0.05 and P<0.01 respectively).
However, only 26.9% of the variability could be attributed to these variables.
38% of the variability could be attributed by a combination of distance VA,
near VA and age. This finding of a significant correlation but high
unaccounted variance is in keeping with other studies.[19,24]
Vision is a highly complex function and so many clinical measures and non
clinical factors of visual function are likely to work together to influence the
manner in which the VI affects the individual. Contrast sensitivity, reading
speed and visual fields would have been obvious additional clinical measures
to consider but are not recorded for all children attending the paediatric low
vision clinic. Therefore, in this study there were insufficient numbers to
analyse this data. In childhood VI, it is important to consider the impact of
wider non clinical factors such as family socio-economic status,
appropriateness and access to support provided by the child’s school and
other providers, peer and family relationships. It is plausible that these factors
also play a part in predicting QoL. Therefore, it is unsurprising that the current
study finds, at best, 38% of the variance can be accounted for. Future studies

14
will need to look at the additional clinical and non clinical factors that combine
to predict QoL scores in children with VI.
By better understanding QoL in childhood VI, and the factors that can be
modified to affect QoL, changes to habilitation services can be made to better
support and personalise the care provided for these children and families.
Care providers can then work to eliminate the postcode lottery of paediatric
low vision services in the UK and promote good quality, uniform, cost effective
paediatric low vision services.
ACKNOWLEDGEMENTS
The author’s would like to thank the Optometry Department at Oxford Eye
Hospital for their support and the two reviewers for their comments.
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does grant on behalf of all authors, an exclusive licence (or non exclusive for
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COMPETING INTERESTS

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Competing interest: None declared.
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