Applying epidemiology to understand visual impairment in childhood: burden, aetiology, diagnosis, management and outcomes.
Submitting InstitutionUniversity College London
Unit of AssessmentPublic Health, Health Services and Primary Care
Summary Impact TypeHealth
Research Subject Area(s)
Medical and Health Sciences: Ophthalmology and Optometry, Public Health and Health Services
Summary of the impact
Our research into the epidemiology of childhood visual impairment has
transformed understanding of the epidemiology, outcomes and impact of
childhood visual impairment in the UK. As a result, changes have been made
to the Newborn and Infant Physical Examination Programme and the National
Vision Screening Programme. Our work has underpinned the development of
new quality standards for paediatric ophthalmology services issued by the
Royal College of Ophthalmologists. Our studies on congenital cataract have
improved the management of this condition nationally. We have involved
visually impaired service users and patient groups directly in our
research to improve quality of life measures and patient engagement.
About two per 1,000 children in industrialised countries have bilateral
visual impairment, with up to a further five per cent having significant
sight impairment in one eye. Most are affected from birth and will
experience a significant lifelong burden of adverse impact on their
development, education, social and emotional wellbeing, and curtailed
occupational and social prospects, with high attendant economic costs for
affected individuals, their families and society. At the MRC Centre of
Epidemiology for Child Health, we have established an integrated and
innovative programme on childhood visual impairment that encompasses
classical, lifecourse, and genetic epidemiology and health services
research, led by Professor Jugnoo Rahi. Our research has transformed
understanding of the epidemiology, outcomes and impact of childhood visual
impairment in the UK and established a series of novel study-specific
clinical networks (most with 150+ consultant ophthalmologists) for rapid
implementation of findings into practice and policy.
We have undertaken a series of national studies of all-cause visual
impairment and of all of the most common (globally) treatable childhood
ophthalmic disorders i.e. amblyopia, congenital cataract, paediatric
glaucoma, ocular anomalies and hereditary retinal disorders. These have
provided the first population-based data on the frequency, distribution
and natural history of these individual disorders together with unbiased
assessment of effectiveness and safety of treatments.
We have shown for the first time that there are major variations in risk
of visual impairment/eye disorders e.g. by socio-economic status,
ethnicity, birthweight and other early life factors and demonstrated a
growing and increasingly complex population at risk [1, 2].
Our longstanding programme on amblyopia, the most common paediatric eye
condition, has shown that contrary to long-held clinical opinion, there is
remarkably limited disutility per se  but that risk of
blindness and its attendant socio-economic consequences occurring through
loss of sight in the non-amblyopic eye is substantial .
Our series of studies on congenital cataract have provided for the first
time internationally accepted population based `benchmark' outcomes data
on visual function, quality of life, and complications  and
identified the risk factors associated with poor outcomes against a
backdrop of evolving surgical approaches. Most recently we have completed
the first national study of intra-ocular lens implantation in infants, the
key surgical innovation in this field, assessing early visual outcomes
with this new approach compared to established surgical treatment and
identifying the point of `equipoise' for clinicians in their choice of
surgical approach. This study established a unique national cohort which
is providing important early insights into the impact of this new
intervention on visual outcomes and iatrogenic complications. In due
course it will provide unique long-term outcomes data.
Our inter-disciplinary programme to understand the impact of visual
impairment has combined health services research and social sciences,
resulting in innovative child-centred methodology and a novel patient/NHS
user research partnerships which have underpinned our development of the
first child-reported measures of quality of life and of functional vision
, which can also be used routinely in the NHS as a tool for
assessing quality and as outcome measures in clinical trials of novel
References to the research
 Rahi JS, Cumberland PM, Peckham CS; British Childhood Visual
Impairment Interest Group. Improving detection of blindness in childhood:
the British Childhood Vision Impairment study. Pediatrics. 2010
 Rahi J, Logan S, Timms C, Russell-Eggitt I, Taylor D. Risk, causes,
and outcomes of visual impairment after loss of vision in the
non-amblyopic eye: a population-based study. Lancet. 2002 Aug
 Chak M, Wade A, Rahi JS; British Congenital Cataract Interest Group.
Long-term visual acuity and its predictors after surgery for congenital
cataract: findings of the British congenital cataract study. Invest
Ophthalmol Vis Sci. 2006 Oct;47(10):4262-9. http://doi.org/ddj6gh
 Rahi JS, Tadić V, Keeley S, Lewando-Hundt G; Vision-related Quality
of Life Group. Capturing children and young people's perspectives to
identify the content for a novel vision-related quality of life
instrument. Ophthalmology. 2011 May;118(5):819-24. http://doi.org/ch4fxm
Details of the impact
a) Development and on-going review of the UK universal child vision
Our research findings provided the first robust evidence base for the UK
National Screening Committee's policy on universal childhood vision
screening and surveillance. This has led to the revised programme status
and standards for the Newborn and Infant Physical Examination Programme
(NIPE) and discontinuation of 9-month and pre-school vision screening
examinations [a]. More recently we have completed a commissioned
systematic review for the National Screening Committee (NSC) which is
currently forming the basis of their policy review of the content and
timing of the 4-5 year/school entry vision screening examination [b].
b) Improving the quality of paediatric ophthalmology services
Our work has underpinned the development of new quality standards for
paediatric ophthalmology services. A number of our publications are cited
in the Royal College of Ophthalmologists (RCOphth) standing report,
Ophthalmic Services for Children (Updated August 2012) for which Rahi
acted also acted as reviewer. Our work provides epidemiological background
and supports recommendations on the involvement of parents, on the early
detection of ophthalmic disorders and on certifying children as
sight-impaired [c]. Our study of the needs and experiences of
families of newly diagnosed visually impaired children informed the
successful implementation of a novel regional-level `key worker' service,
the Great Ormond Street Hospital (GOSH) Ophthalmology Community Link Team,
which provides information, support and liaison to families of our
patients [d]. This was taken as a model of key worker provision
and cited in the above document.
Following on from this, Rahi helped to develop Quality Standards for
Paediatric Ophthalmology on behalf of RCOphth [e]. These quality
standards are now in regular use in clinical practice. For example, this
can be seen on the GOSH website, which describes how it has measured its
services against the Quality Indicator Tool that we helped to develop [f].
In 2012, Rahi contributed to the first Atlas of Variation in Healthcare
for Children and Young people which was produced by the Department of
Health's QIPP (Quality, Innovation, Productivity and Prevention) programme.
This document presented variations across the breadth of child health
services provided by NHS England together for the first time to allow
clinicians, commissioners and service users to identify priority areas for
improving outcome, quality and productivity. Map 7 highlighted variation
in the proportion of eligible premature babies tested for retinopathy of
prematurity (ROP) within the recommended timeframe, and made
recommendations on improving services [g].
c) Improving the management of congenital cataract
Congenital cataract is the most common surgically treatable cause of
childhood visual impairment worldwide. Our studies on congenital cataract
have been conducted through the British Congenital Cataract Interest
Group, a network comprising over 150 ophthalmologists which we established
in 1995. This has led to timely implementation of findings to improve
clinical practices and provide improved outcomes information for parents
of affected infants [h]. For example, during our ongoing research
on intraocular lens implantation, we have used this network to spread use
of the data collection forms that we developed as part of the study. These
are now more widely used as routine clinical pro-formas for patient case
notes, leading to standardisation of key aspects of management nationally.
GOSH, for example, report that:
"The per-operative data entry proforma currently used by our surgeons
at GOSH was developed as part of the IOLu2 [Intraocular lens under 2]
study by Dr Lola Solebo in 2009... Not only is [it] still used and can
be sampled for future studies it is now used by all the other surgeons
in the team... The team has found it promotes good record keeping when
performing childhood cataract surgery... It has also be shared with many
other centres through our lectures and when we have visiting
ophthalmologists. The proforma helps the department to enter clinical
data in an efficient, standardised and thorough manner" [i].
d) Improving patient involvement in research
Our research over the years has directly involved service users and
patient groups. For example, our systematic review of Patient-reported
outcome measures (PROMs) in paediatric ophthalmology involved a service
user (visually impaired herself and parent of a visually impaired child)
as a co-investigator [j].
In the first stage of our work to develop our `quality of life'
instrument, we worked with the pupils in the Visual Impairment unit at
Exhall Grange, a specialist school in Coventry that caters for children
and young people with a range of disabilities. Specifically, we conducted
focus groups and interviews with these pupils to help us identify the
content for our instrument. In the focus groups we elicited the children's
thoughts and views about the impact of living with visual disability. The
mobility officer working with these children, who helped facilitate the
focus group discussion, was struck by how much the children opened up
about their lives and felt there was a broader benefit of this context.
Subsequently, he reported to us that as a result of this experience, the
Visual Impairment unit initiated a `forum for the visually impaired
pupils' where the pupils meet weekly or monthly for an `around the table'
discussion of any issues that they might have (modelled on their
participation in our research). Finally, the school was commended by
Ofsted for this initiative [k].
Sources to corroborate the impact
[a] The Clinical Director of the NIPE screening programme states: "Professor
Rahi has played a major role in relation to the Newborn and Infant
Physical Examination. On behalf of the National Screening Committee, she
and her team have reviewed the evidence relating to screening for vision
and ocular abnormalities in preschool children. The review and her other
contributions, have allowed us to strengthen and improve screening where
there is evidence to support it, while we have been able to cease
screening at ages when there is no benefit to be had." Copy
of email available on request.
The Director of the National Screening Committee (Public Health England)
has confirmed in an email that "The UKNSC commissioned a review of
vision screening in 4-5 years olds from Jugnoo Rahi. This work has been
developed in close collaboration with the UKNSC. It has been consulted
on through the UKNSC process and will form the basis of a policy
recommendation to be made by the UKNSC in November 2013." Copy of
email available on request.
Guidance cites the following:
- Citing Rahi J et al. Meeting the needs of parents around the time of
diagnosis of disability in their children: evaluation of a novel scheme
for information, support and liaison by key workers. Pediatrics
2004;114:e477-82. Supports recommendation: "Parental advocacy
should be supported and encouraged through provision of information
and social and emotional support, both in the context of the
management of individual children as well as more broadly in relation
to the planning of ophthalmic services for children with visual
- Citing . Supports the observation that: "The
majority of children in the UK with severe visual
impairment/blindness... have additional and often multiple serious
motor, sensory or learning impairments and/or serious chronic
- Citing Rahi J, Dezateux C. Epidemiology of Visual Impairment. In:
David T, ed. Recent Advances in Paediatrics 19. London: Churchill
Livingstone, 2001: 97-114. Research provides epidemiological basis:
"Thus there are at least 4 newly visually impaired children each day
in the UK and around 2 per 1000 children in a given population are
visually impaired or blind."
- Citing . Supports the statement: "The College
endorses the recommendations of the fourth edition of "Health for all
children" issued in 2003 and subsequently in the Child Health
Promotion Programme and the Healthy Child Programme regarding
screening, in order to promote early detection of ophthalmic disorders
or reduced vision."
- Citing Cumberland PM, Peckham CS, Rahi JS. Blindness certification of
children 1 year after diagnosis: findings from the British Childhood
Vision Impairment Study. Br J Ophthalmology. 2010
Dec;94(12):1694-5. Supports recommendation: "All eligible
children and young persons should be offered certification as
sight-impaired or severely sight impaired where indicated"
[g] Atlas of Variation http://www.rightcare.nhs.uk/index.php/atlas/children-and-young-adults/
and for actual pdf see: https://docs.google.com/file/d/0B8ePB71diJorM0ZMQzVqLWhFUjA
(Rahi is listed on p.84 as a contributor to Map 7).
[i] Impacts corroborated by Chris Lloyd, Chair of the Paediatric
Subcommittee of RCOPhth who says: "the unit at ICH/UCL has been hugely
influential in improving the care of children with congenital
cataracts(CC). You have enabled accurate biostatistical analysis of
children affected by CC — the most common surgically treatable cause of
childhood visual impairment. This has been facilitated by the
establishment of the British Congenital Cataract Interest Group - a
network comprising over 150 ophthalmologists in the UK and Ireland which
you set up in 1995." Copy of email available on request.
[j] Email from Consultant Ophthalmic Surgeon at GOSH. Available on
[l] Copies of correspondence with the Mobility Officer at Exhall Grange
School are available from Centre of Paediatric Epidemiology and
Biostatistics, UCL ICH. Contact details provided.