6. Improving eye care and learning potential for children with Down’s syndrome.
Submitting InstitutionCardiff University
Unit of AssessmentAllied Health Professions, Dentistry, Nursing and Pharmacy
Summary Impact TypeHealth
Research Subject Area(s)
Medical and Health Sciences: Ophthalmology and Optometry, Public Health and Health Services
Summary of the impact
Cardiff University has established the world's largest single cohort of
children and young adults with Down's syndrome in which visual deficits
have been characterised. Cardiff research studies over 20 years have
informed evidence-based guidelines published by the Department of Health
and national practitioner bodies for the recognition and practical
management of common visual problems in children with Down's syndrome.
Consequently, eye care specialists now recommend bifocals for these
children. The Cardiff research has also supported changes to teaching
methods and resources for children with Down's syndrome. Collectively
these children are now benefiting from better eye care and improved
learning and educational opportunities.
Beginning in 1992, with grant support from the Down's Syndrome
Association and the Medical Research Council, Dr Margaret Woodhouse (1974
to present, Lecture and Senior Lecturer) and her team from Cardiff
University began to build up a unique study group of children and young
people with Down's syndrome. As Director of the University's Special
Optometry Assessment Clinic (founded in 1993), Woodhouse has driven the
expansion and monitoring of the cohort over the past 20 years. This clinic
acts as a flagship service for the treatment of visual deficits in
children and young people. It is the only clinic of its kind in primary
healthcare in England and Wales, seeing over 200 children with Down's
syndrome each year. The Cardiff longitudinal database now comprises over
250 children and young adults with Down's syndrome ranging in age from 1
to 25 years; it is the largest database of its kind in the world.
Longitudinal data and studies from this research programme have
contributed to a series of important research findings, detailed below.
The causes of poor vision in children with Down's syndrome
Woodhouse and colleagues showed that in the early weeks of life the
occurrence and distribution of refractive errors are similar in children
with Down's syndrome to those of typical infants. However, the process
known as `emmetropisation', which reduces these errors in typical infants,
fails in infants with Down's syndrome; refractive errors do not diminish
with age in these children. The Cardiff team showed that by the time they
go to school, ten times more children with Down's syndrome need glasses
compared with typical children [3.1]. Further data analysis of
the same cohort (n=182) showed that the prevalence of oblique corneal
astigmatism, which causes blurred vision and which is uncommon in typical
children, increases to an incidence of 45% in teenagers with Down's
However, refractive errors are not the only cause of poor vision in
children with Down's syndrome. The Cardiff team through research
examinations (using the Cardiff Acuity Test developed by Woodhouse in 2005
and licenced (royalty-free) across 38 countries - ca. 150 licenses p.a. -
specifically to assess the vision of infants and children who have
difficulties in communication) showed that up to three-quarters of
children with Down's syndrome display inaccurate accommodation (i.e.,
inability to focus through shape adaptations of the lens). By the age of
12 months, typical children have accurate eye accommodation that rarely
deteriorates through childhood; the accommodation defect in children with
Down's syndrome persists even when they wear spectacles to correct fully
long or short-sight [3.3].
The case for bifocals
The Cardiff researchers discovered that bifocal spectacles corrected
defective accommodation in children with Down's syndrome. Children wearing
bifocal lenses achieved accurate accommodation and preferred to wear their
bifocals full-time rather than changing back to conventional spectacles
for out-of-school activities [3.4]. The team also found that a
significant proportion (35%) of children with Down's syndrome prescribed
bifocals began to accommodate accurately after wearing bifocals for
roughly three years; these children returned successfully to single vision
A persistent visual deficit
However, it appears that children with Down's syndrome have an additional
visual deficit that is not correctable with glasses. Recognising that
vision tests rely to some extent on the cognitive ability of the subjects,
the Cardiff team (in collaboration with US investigators) led research
using electro- encephalography (EEG) to measure visually stimulated brain
activity. These studies revealed that visual deficits in children with
Down's syndrome cannot be explained by poor cognitive performance alone [3.6].
The deficits remain even when the child's visual function is fully
optically corrected and assessed by entirely objective means [3.6].
By the time children with Down's syndrome enter school, their visual
capabilities are significantly poorer than their classroom peers.
In summary, prior to the Cardiff research the extent and natural history
of refractive errors in children with Down's syndrome was unknown. For
example, focusing for near tasks had not been measured at all in children
with Down's syndrome, the assumption being in clinical practice that, as
in typical children, accommodation would be good. The Cardiff research has
redefined the landscape for visual deficits in children with Down's
References to the research
[3.1] Woodhouse, J.M., Pakeman, V.H., Cregg, M., Saunders, K.J.,
Parker, M., Fraser, W.I., Lobo, S. and Sastry, P. Refractive Errors in
Young Children with Down Syndrome. Optometry Vision Sci. (1997) 74:
[3.2] Al-Bagdady, M., Murphy, P.J. and Woodhouse, J.M.
Development and distribution of refractive error in children with Down's
syndrome. Brit. J. Ophthalmol. (2011) 95: 1091-1097. http://dx.doi.org/10.1136/bjo.2010.185827
[3.3] Woodhouse, J.M., Cregg, M., Gunter, H.L., Sanders, D.P.,
Saunders, K.J., Pakeman, V.H., Parker, M., Fraser, W.I. and Sastry
P. The effect of age, size of target and cognitive factors on
accommodative responses of children with Down syndrome. Invest. Ophth.
Vis. Sci. (2000) 41: 2479-2485. http://www.iovs.org/content/41/9/2479.full
[3.6] John, F.M., Bromham, N.R., Woodhouse, J.M. and Candy, T.R.
Spatial vision deficits in infants and children with Down syndrome.
Invest. Ophth. Vis. Sci. (2004) 45: 1566-1572. http://dx.doi.org/10.1167/iovs.03-0951
Since 1994 Woodhouse and her team have received over £800K external research
funds to support the work with some examples below. (Note: Cardiff
University staff in bold).
• Welsh Assembly Government. Oct 2004-06. Ocular morphology in people
with Down's syndrome (PI: Woodhouse). £62,000.
• National Eye
Research Centre. April 2000-03. Factors Limiting Visual Acuity and
Contrast Sensitivity in Children with Down's syndrome (PI: Woodhouse).
• PPP Healthcare Medical Trust. April 2000-03. The impact and management
of visual defects in children with Down's syndrome (PI: Woodhouse;
CIs: Fraser, Bennett-Gates). £204,000.
• National Lottery
Charities Board with Mencap. Oct 1999-2002. Visual dysfunction in children
with Down's syndrome: clinical and molecular studies of myopia (PI: Woodhouse;
CIs: Erichsen, Guggenheim, Owen). £251,000.
• Medical Research Council. 1994-97. Visual and cognitive development in
infants and young children with Down's syndrome (PI: Woodhouse,
CI: Fraser). £195,805.
Details of the impact
Educational guidance in the teaching and learning of children with
Historically, children with Down's syndrome struggle with literacy
skills, including exercises that require the ability to `write on lines'
which in particular was previously assumed to be due to poor fine motor
control. The Cardiff work challenged this notion, showing that the problem
stems from their poor vision. From this research the Cardiff team
recommended that darker lines would improve the classroom performance of
children with Down's syndrome. Teachers and parents have confirmed that
children with Down's syndrome are better able to follow lines if they are
darkened,"Big and Bold" [5.1]. In direct correspondence
with Woodhouse, one parent states: "One of [Ben's] targets at school
was to write on the line which he couldn't do. It turned out the line
was in pencil so I suggested that perhaps he couldn't see... they then
drew the lines in pen and instantly he could write on the lines!"
Cardiff's studies also showed that most children with Down's syndrome who
were prescribed bifocals made an active choice to wear them all the time,
not just in the classroom. The benefit of wearing bifocals is summed up in
an email from the mother of Ethan, aged 3, a regular attendee of the
Special Assessment Clinic in Cardiff: "... he took to the bifocals
straight away and hasn't put his old glasses back on since wearing them.
[He is] steadier on his feet, has better communication and attention
when looking at flash cards and so on."
A recent study by an independent Canadian research team examined
educational practices in children with Down's syndrome. The study
confirmed the benefits of the Cardiff research-led recommendations that
bifocals improved focusing for children and the wearing of bifocals led to
a significant improvement in literacy and visual perceptual skills [5.2].
Cardiff's research findings and recommendations have been embraced by the
Down's Syndrome Association, the only organisation in England, Wales and
Northern Ireland which supports people with Down's syndrome at every stage
of life. Since 2008 the Association has used the Cardiff research in its
educational guidance [5.1] on the modification of teaching
materials and practices, and the need for bifocal spectacles. This
guidance is provided to schools and is also available for download [5.3].
Between February 2012 and September 2013 the guidance has been downloaded
9561 times [5.1]. The All Party Parliamentary Educational
Advisory Group on Down's Syndrome has published a report [5.4]
on educational practices that includes the Cardiff-research findings on
visual deficits, the need for bifocals and of problems with writing on
lines. The DSA Educational packs [5.3] that underpinned by the
Cardiff research [5.1] are cited.
The Down's Syndrome Association uses the Cardiff research findings in its
campaigns to benefit children with Down's syndrome [5.1]. For
example, in February 2012 the Down's Syndrome Association has used the
Cardiff research findings in its newsletter to its 7,500 UK members. The
"Focus on Vision" theme of the Association's 2013 Awareness Week (18-23
March 2013) specifically sought to raise attention among schools, families
and professional groups of the issues arising from the Cardiff research;
the work of Woodhouse and her team was explicitly acknowledged on the
Awareness Week web pages. As part of the week's campaigning, the
Association distributed its educational packages to all 286 Local
Education Authorities in England and Wales [5.1] and to 138
related charities. A recent poster campaign by the Association focused on
the specialist eye care needs of children with Down's syndrome was
published in Optometry Today (March 2013), which has a circulation of
20,000 within the optometry profession. Cardiff's research has formed a
key part of guidance provided to parent support groups throughout the UK
and Ireland, along with local professional associations [5.1],
and is also reaching Down's syndrome support associations beyond the UK,
for example in USA [5.5].
Eye care practice guidelines for children with Down's syndrome
The Cardiff research on inaccurate accommodation in children with Down's
syndrome and the successful correction of this deficit using bifocal
spectacles has led directly to changes in the UK eye care management of
these children. Information for parents published in 2010 by the
Department of Health acknowledges the visual impairments and Cardiff's
research [5.6]. They recommended eye tests for children with
Down's syndrome to include the endorsed measurements of their visual
accommodation and the prescribing of bifocal spectacles to correct any
deficit. This has changed the way eye-care practitioners manage children
with Down's syndrome [5.7].
The Down's Syndrome Medical Interest Group (DSMIG) publishes
evidence-based guidelines for minimum standards of health surveillance
aimed at UK and international paediatricians. It has a membership of over
150 clinicians. Dr Woodhouse was invited to become the group's first
non-medical health care practitioner member in recognition of her
contributions in the field of healthcare for children with Down's
syndrome. The group use the Cardiff research in its `Vision' guidelines [5.8,5.9]
(updated in 2012). The DSMIG guidelines and the research of the Cardiff
team are adopted by Paediatric Opthalmologists in their practice [5.10].
In summary, the unique structure provided by Cardiff University's Special
Optometry Assessment Clinic has enabled the conduct of distinctive
research that has led to the measurement of visual accommodation being
introduced into the recommended UK eye-care management for children with
Down's syndrome and to the prescribing of bifocal spectacles to these
children. Furthermore, the Cardiff research showed that while persistent
deficit in visual acuity in these children is not due to reduced cognitive
ability it negatively impacted upon educational/classroom experiences,
findings which have led to changes internationally in educational guidance
in the teaching and learning practices for children with Down's syndrome.
Sources to corroborate the impact
[5.1] Statement from Chief Executive Down's Syndrome Association. How
Cardiff's research findings and recommendations have been embraced by the
Down's Syndrome Association in the Association's educational guidance
aimed at teachers and parents, and in the Association's optical health
advice aimed at professional healthcare providers and parents.
[5.2] Independent educational research confirming the Cardiff
research-based recommendations for the use of bifocals to improve in
literacy and visual perceptual skills in children with Down's Syndrome.
Nandakumar, K., Leat, S.J. Bifocals in children with Down syndrome (BiDS)
- visual acuity, accommodation and early literacy skills. Acta Ophthalmol.
(2010) 88: 196-204.
[5.3] Links to Down's Syndrome Association support packages for primary
and secondary education: http://www.downs-syndrome.org.uk/information/for-professionals/education.html.
For example the primary school strategies that can be adopted:
with pp 3 and pp 14 acknowledging Woodhouse and Cardiff University
[5.4] All Party Parliamentary Educational Advisory Group Report (2012)
indicates the challenge of visual deficits in Down's Syndrome children and
the need for bifocals pp 8-9. The DSA Educational packs are referenced pp
[5.5] USA State Down's Syndrome Association - Arkansas (USA) promoting
the bifocal research findings of Cardiff and Woodhouse (p 3).
[5.6] Department of Health (2010). `Information for parents: Down
syndrome'. Raises as one of the topics Visual Impairment (p 55) and cites
(p 55) the Cardiff team and the prescribing of bifocals.
[5.7] Statement from Senior Orthoptist, Leeds Teaching Hospitals - how
Cardiff research has influenced eye-care practitioners managing children
with Down's syndrome.
[5.8] Guidelines (2012) from DSMIG citing the Cardiff Research (pp 1-2),
the prescribing of bifocals (bullet 7) as a good practice point. http://www.dsmig.org.uk/library/articles/guideline-vision-5.pdf
[5.9] Statement from paediatrician member of the Down's Syndrome Medical
Interest Group (DSMIG). DSMIG's use of the Cardiff research in its vision
guidelines, and impact of Cardiff research upon vision healthcare for
children with Down's syndrome.
[5.10] Statement from paediatric ophthalmologist, Fellow of The Royal
College of Ophthalmologists. Influence of Cardiff research upon practice.