Vision impairment (VI) has a significant impact on an individual's ability to engage with everyday tasks. Severe early-onset VI presents different challenges to adult onset visual loss since reduced visual input presents a major obstacle to the acquisition and development of fundamental developmental skills in early and later childhood. Early referral of the child with reduced vision is vital to ensure accurate diagnosis and prompt treatment of any modifiable aspects of the condition. Guidance to ensure optimisation of developmental opportunity through adaptation of play and care is vital from the earliest stages. Cognitive and social challenges occur throughout education and need to be understood and addressed through skilled support. Multiagency input, particularly from health and education, is vital to minimise the risk of adverse outcomes and promote successful transition to independent adulthood. VI may also arise in a variety of neurological disorders, and diagnosis and assessment to ensure appropriate adaptations are made is also crucial for this group of children. This review provides the paediatrician with information on diagnosis, assessment, long-term support needs and outcomes.
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Although childhood vision impairment (VI) is often grouped with hearing impairment as a sensory disorder, severe early-onset VI is more appropriately considered as a major neurodevelopmental disorder, given its impact on multiple developmental processes. Its relative rarity compared with other neurodevelopmental conditions means that some paediatricians (and ophthalmologists) may not be familiar with the input required to diagnose and optimally manage this long-term condition. The frequency of direct paediatric input in audiology services and the relative absence of ophthalmic and education professions in the child development centre1 may further compound the paediatrician's lack of familiarity with the child with a visual disorder.
The impact of VI on the child and family is considerable, and management of the developmental and behavioural consequences as well as of comorbid aspects of the underlying condition is required. Paediatricians therefore need to be equipped to understand and support children with this low-incidence, high-impact condition.
The annual cumulative incidence of severe VI and blindness by the age of 15 years in the UK is 6/10 000,2 with almost 80% having an additional non-ophthalmic disorder, which may be significant. A prevalence estimate of 2.4 per 1000 has been given for all levels of VI,3 and while this was based on parental reporting, the results are comparable to those reported.3 The causes of VI in the UK, classified anatomically are, ‘cerebral’ (cerebral VI) (40%), retina (24%) and optic nerve (23%),4 with some variation according to the severity of the VI.5 In the UK, >70% cases of severe VI have an early onset in infancy, but delay in recognition and diagnosis can occur particularly in the absence of a visible ocular abnormality or where poor visual responses are overshadowed by other concerns. Significant VI in children with severe movement limitation can be masked and remain unrecognised for years.
Who is a vision-impaired child?
Visual acuity is a measure of the ability to see fine detail and is the main criterion used for VI classification. Several terms (blind, low vision, partial sight, registered sight impaired), which attempt to quantify severity or predict future support needs, can be confusing. The WHO classification of VI is based on the International Classification of Diseases, Tenth Revision (ICD-10), which lists four categories of normal, moderate, severe and blind (table 1). Classifications based solely on acuity inevitably do not address problems of higher visual function, which for some children (and adults) may be significant and can occur in the context of normal or reduced acuity.
In the UK, VI is the only major childhood disability that formally ‘certifies’ the degree of impairment by issuing a Certificate of Visual Impairment. Certification creates eligibility to join a local Social Service-held Register of sight impaired persons (Registration); see box 1. Children can be certified, registered and offered a social care assessment; however, their primary need is for early developmental support from specialist teachers and the child development team, and referrals to these services should be made as soon as impairment is identified. Additional help that may be provided later following a social care assessment may be valued by parents.6 Certification and registration do not function as a direct route to early educational and developmental support.
The process of being issued with a Certificate of Visual Impairment (BP1 in Scotland and A655 in Northern Ireland), a copy of which is also sent to the local Social Services department.
Means being voluntarily included on the local authority register of visually impaired people to facilitate the provision of social care. This register is usually held by Social Services.
Registration cannot proceed without certification.
Neither process is mandatory in the UK.
An important function of the certification system is to gather epidemiological data on the causes of VI, which is crucial for monitoring trends and planning services. However, judgements made about the degree of severity at the point of certification in a young child may not equate to those applicable in later childhood, when acuity may have matured and can be measured accurately. Additional ways of investigating the epidemiology and manifestations of cerebral VI will also be required, given the challenges in distinguishing visual and non-visual components of early poor visual responses in children with brain pathology and the multiplicity of other problems that such children may experience.
Rates of certification and registration vary in different parts of the UK, and variations to reporting systems for children may emerge in the future. Meanwhile, it is vital that professionals need to understand its strengths and limitations. A current tendency to use certification/registration status as a shorthand indicator of current visual function in clinical correspondence should be discouraged. Providing detailed information to families and professionals will ensure that changes are appropriately disseminated.
Acknowledging that ‘A vision impairment is one which interferes with a child or young person's development, learning or achievements’ (after Flanagan et al7) should guide the medical practitioner in making appropriate clinical and educational referrals at the earliest time point.
Diagnosis and assessment
Any infant or child suspected of having VI requires full ophthalmic assessment to determine the child's current level of vision, the underlying cause and the presence of treatable components such as refractive error.
Observation and clinical examination may confirm poor visual responses, document abnormal ocular appearance or eye movements, and provide diagnostic examination findings. However, fundus abnormalities may be absent or subtle in conditions such as a retinal dystrophy, and in this instance an electroretinogram is diagnostic. This may require referral to a regional centre. Brain imaging may be also helpful, and referral to the regional paediatric ophthalmology and neurology or neurodisability services should be considered. A ‘diagnosis’ of delayed visual maturation (DVM) should not be made if vision remains poor since by definition DVM can only be confirmed in retrospect.8
Advances in ocular genetics have been considerable, and the list of identifiable mutations grows quickly. Genetic counselling provided by the regional genetics service is important for affected families.
Many conditions that manifest early VI have systemic associations that may be evident or require further investigation. Some examples are given in table 2.
Although not presenting with VI, retinoblastoma manifesting as a white pupillary reflex may result after treatment of bilateral disease. Retinopathy of prematurity also remains an important cause of VI and will generally be identified through ophthalmological monitoring.
In a child with physical disability and poor visual responses, the ophthalmic examination is critical. However, if previous eye examinations have been normal, a mistaken belief that this equates to proof of normal vision may arise. Evidence of visual detection at whatever level must be sought, and objective observations of repeatable responses to visual materials will need to be made. Purposeful and non-purposeful eye movements in response to presentation of test materials need to be carefully distinguished in the child who is unable to reach or point and who may have difficulty responding to verbal instructions. A diagnosis of severe VI can be difficult to make later on if missed when the child is young.
Some systemic conditions include ocular abnormalities—for example, retinal dystrophy—among their many manifestations. Although attention may be concentrated on other features, such as seizures or growth, assessment and management of the visual component of the disorder is also warranted.
Determination of the child's level of vision is important not only because uncertainty compounds parental distress,9 but also to form the basis for advice on vision and developmental promotion. A detailed history that invites open descriptions is particularly helpful in children with a low level of vision or in children with limited movement and vocalisation.10 Parents can feel uncertain about their child's skills, and exploring their observations can help to build their confidence in understanding what their child can and cannot do, and how best to respond.
Acuity assessment for young children is based on resolution of stripes or lines, and for older children on recognition of pictures or letters. For children with extremely low levels of vision, qualitative information can be gained from very simple measures of ‘detection vision’.11 ,12 Qualitative comments on the child's overall visual performance and a note of any unusual behaviours should be made and explained where possible.
Visual field assessment is challenging but may be informative, though it should be remembered that impairments in visual attention may influence the child's capacity to respond to confrontation testing methods.
For the young child with suspected cerebral visual impairment, occurring most commonly in the context of known brain pathology and other neurodevelopmental concerns, evaluation of ocular function and vision should proceed in the same way. A wide range of additional manifestations of cerebral visual impairment is reported in the literature, but these are not inevitable and may not emerge until the child is older. There may also be overlaps with other aspects of development, and thus a multidisciplinary approach to assessment is required. Initial assessment should always include the basics of ocular function, visual acuity, eye movements and visual field. For older children in whom there is concern about visual perceptual or visuomotor difficulty, history-taking approaches may identify areas of possible difficulty, following which a detailed cognitive and visual perceptual assessment can follow.13 ,14
Ocular function and vision in early-onset conditions should be monitored
Some conditions, particularly retinal dystrophy, may be progressive. For most others, some improvement can be expected as the visual system matures.8 Some conditions, particularly optic nerve hypoplasia and oculocutaneous albinism, show particular improvement during the first year of life, suggesting an element of DVM.8 Refractive errors, if present, should be monitored to ensure that appropriate spectacle correction is provided. A trial of spectacles to correct refractive error is warranted in most levels of visual impairment; however, the purpose of spectacles should be explained carefully. The use of the visually evoked potential (VEP) is a powerful research tool, but is often used uncritically in the clinical situation to estimate visual acuity or future potential. We caution against this approach as VEP does not provide a behavioural acuity.
Conditions with onset in later childhood
Some retinal dystrophies manifest in the childhood years. The most important of these, presenting with visual loss, are Stargardt's macular dystrophy, Batten's disease, retinitis pigmentosa, Leber's hereditary optic neuropathy and optic pathway tumours.
Effects of VI on learning and development
Severe VI has a substantial impact on early childhood development. Vulnerabilities in motor, cognitive, language, social and attentional domains are well documented,11 ,15 ,16 as is the risk of developmental setback (plateauing and regression of cognitive and social development) in the toddler years.17
Some children overcome early cognitive delay and social weaknesses, but in others problems persist.18 The relationship between VI and autistic spectrum disorder (ASD) has long been debated. The risk of ASD is elevated in individuals with VI, though the influence of other factors requires further research.19 The frequency of social difficulty and the lack of diagnostic tools appropriate for this population contribute to diagnostic challenges. Some of the additional disability for children with VI is a secondary consequence of the VI itself, highlighting the need to develop more effective interventions.
VI affects learning and social relationships throughout life, and those with additional needs are at even greater risk of poor educational and well-being outcomes compared with those with isolated VI.20–22 VI impedes a child's ability to fully access the school curriculum. Extra effort is required to meet cognitive demands and to read in braille or large print, as well as to grasp concepts that are more readily understood through sighted means and incidental learning. Children with VI are more likely than other children to feel tired at school and less likely to feel that they can do things as well.22
Lower quality of life has been reported in children and young people with VI compared with their peers.23 According to parent and teacher ratings on the Strengths and Difficulties Questionnaire, children with VI are at higher risk of psychosocial disorders compared with sighted children, with those with additional disabilities at greatest risk.24 Tadic et al25 observed that the psychological impact of VI is greater for later compared with earlier onset. They suggest that the interaction of multiple factors such as a child's personality, adjustment to their vision, family circumstances and professional support is more likely to underpin their quality of life rather than the severity of their VI.
Participation is defined by the WHO as ‘involvement in life situations’ and can include access to friendships and social groups, as well as to leisure activities. Considerable scaffolding from adults is often required to establish and maintain effective social interaction with peers. While there is evidence that many children with VI have good friends,21 ,22 ,26 others struggle with establishing and maintaining peer relationships25 and are susceptible to bullying.21 ,22
VI can impose functional restrictions and limitations on participation with peers in family and community-based activities.25–27 Families report benefit from contact with local VI charities running local events.
Young people, especially those who are discharged from eye clinics at an early age, do not always have a good understanding of their VI: its cause, its risk of progression or where to go for information. One useful source of information is the following website: http://www.vincyp.scot.nhs.uk/conditions/. Voluntary sector organisations representing specific conditions are also a source of information (eg, http://www.albinism.org.uk).
Fluctuations or deterioration in sight can have a significant impact on a young person's education or employment prospects, especially at key periods such as during exams or transition. It is critical that the clinician investigates such changes to determine whether this is due to superimposed new pathology or to a change in the known pre-existing condition. In some instances, treatment may be indicated. An unexpected deterioration in sight can be particularly functionally problematic, with both the young person and the education professionals that support them struggling to adapt to the sudden change in circumstances such as need to a change of reading medium.28 Uncertainty surrounding the diagnosis and future prospects can have a significant emotional impact.25
Young people with VI are less likely than their peers to be in education or employment.29 At the time of transition from school, individual vulnerabilities become more apparent, with those who are less resilient proving less able to cope with the structural failings of postschool settings and systems. Factors increasing vulnerability are VI severity, low expectations, poor independent mobility and everyday living skills, and lack of independent learning skills. Factors increasing the likelihood of employment are good educational qualifications, independent mobility and everyday living skills, peer social skills, social networking, assistive technology skills and work experiences.30 ,31
Despite these challenges, many young people do report favourably on their quality of life25 and many do well academically.
How children and young people are supported
Children and young people with VI require high levels of specialist support to promote their cognitive development, communication, social and independence skills. The importance of early intervention cannot be overemphasised, with support needed not just for the child but also practical developmental advice and emotional support for parents.
In the UK, the lead professional in supporting infants and children with VI is usually the local authority specialist VI service qualified teacher for children and young people with vision impairment (QTVI). QTVIs provide support in the home as well as in education settings. Referral to the VI service should be made as soon as possible after a VI has been identified and should not depend on certification status or process. Delays in referral can have a significant impact on the parent as well as the child.6 A key resource for use by parents with QTVIs is the Developmental Journal for Babies and Children with VI.15
There are only 12 specialist schools for blind and partially sighted learners in the UK, supporting fewer than 1000 pupils, most of whom have multiple needs. There are six specialist further education colleges for learners with VI, all in England.
The majority of children and young people with VI are educated in mainstream schools, with around a third in special schools for pupils with learning or other disabilities. As most mainstream and generic special education settings are unlikely to have sufficient knowledge and expertise to meet the child's/young person's needs, specialist advice and coordination of support is usually provided by the peripatetic QTVI. Another key professional is the Registered Qualified Habilitation Specialist or mobility teacher/habilitation worker whose role is to teach independent mobility and everyday living skills.
As well as enabling children and young people with VI to access the academic, or ‘core’ curriculum, QTVIs provide support and training in the ‘additional curriculum’, a wider range of skills that lie outside the standard curriculum—the ‘additional curriculum’.32
The underpinning principles of specialist educational input are independence and autonomy, but the demands of the academic, are often prioritised over the ‘additional’, curriculum. A distinction is made between ‘learning to access’—providing the child with the skills to learn independently—and ‘access to learning’—providing the child with access to appropriate information in order to learn about a particular curriculum area.33 If too much emphasis is placed on the latter, this can lead to overdependency on adults (such as teaching assistants (TAs) and young people fail to develop the skills needed to make a successful transition to independent adulthood). Children and young people with VI feel that sometimes functional restrictions are imposed by those supporting them rather than by their own abilities.27
Braille is one of the specialist skills in the ‘additional curriculum’. In England, around 1060 children and young people are known to read and write through braille, which is 4% of those receiving specialist educational support.34 There are several challenges associated with learning braille and the teaching of braille literacy. Reading braille involves different strategies from reading through print. Braillists generally read more slowly and less accurately than fully sighted print and low-vision print readers. At age 9, the age difference in reading speed is just under 4 years, rising to almost 6 years by age 13.35 Because the population of braillists is so small and unevenly distributed, it can be difficult for QTVIs to maintain their professional skills in braille teaching. The decision whether braille or large print (or both) should be a child's main reading medium can be problematic for children with some sight. Another concern is that too much responsibility may be placed on TAs for the day-to-day teaching of braille in mainstream schools.
Specialist support for children and young people with complex needs
Most children with VI and complex needs are educated in special schools for pupils with learning, autism or other types of disability where several different education and health professionals may be involved in their support. As many of the strategies for teaching children with complex needs rely heavily on sight (eg, for non-verbal children or children with autism), alternative approaches have been developed for children with VI.32 Advice from a QTVI is therefore essential to avoid the risk of inappropriate educational or therapeutic adaptations being used with potential adverse consequences for the child.
Multidisciplinary team working
Children with VI and those with complex needs in particular require a multidisciplinary approach. In England, more efficient multiagency contact may be anticipated following the introduction in 2014 of a statutory assessment process leading to a single Education, Health and Care (EHC) plan for children and young people with special educational needs and disabilities (SEND). In practice, while VI education services in 72% of local authorities claimed involvement in multidisciplinary meetings with health and social care, there were differences in the groups of children the meetings applied to and the contexts in which they took place. Criteria for EHC assessment for children with VI also varied widely across local authorities, with a third making no direct reference to VI.34
Competence in the use of assistive technology such as screen readers and magnification software promotes independent learning and better outcomes in education and employment.32 ,33 ,36 The accessibility of tablets and smart phones means that mainstream technology is increasingly important in the education and social inclusion of children and young people with VI. For children with complex needs, information technology can be used in a variety of ways such as supporting communication, helping to shape understanding of cause and effect, and enabling participation in group and recreational activities. Resources and information on information technology are published on the websites of several VI voluntary organisations (eg, Royal National Institute of Blind People: http://www.rnib.org.uk/services-we-offer-advice-professionals-education-professionals/technology-education; Royal London Society for Blind People: http://www.rlsb.org.uk/tech-hub; Blind Children UK:
Is support being rationed?
In the UK, recently some local authorities have responded to public sector budget cuts by raising the threshold for eligibility for VI service support. In a few, QTVI provision is limited to those with the most severe degree of impairment or to those certified. This policy is at odds with the functional definition of childhood VI discussed earlier and risks leaving children with mild and moderate VI stranded in the education system without appropriate support.
The role of the voluntary sector
The voluntary sector can play a key role in supporting children and young people with VI and their parents, also professionals. Parents need information at the time of their child's diagnosis and at key transition points or as new issues emerge. As well as clinical information about their child's sight condition, they require parenting guidance, how to access play and leisure activities, educational provision and sources of financial support. Sight loss charity telephone helplines and print and online factsheets are a valuable source of information. National and local VI societies also provide a range of social and leisure opportunities for children and young people and practical support and guidance on topics relevant to them. Every local authority in England is required to publish in its ‘SEND Local Offer’ details of voluntary sector provision. A central source of information for parents of children with VI is the Vision2020 UK ‘Starting Point’ guide (http://www.vision2020uk.org.uk/startingpoint/).
VI has significant implications for development and learning. For the community paediatrician, close professional relationships with the ophthalmic and specialist teaching teams are vital to ensure early referral and intervention, supported by prompt sharing of information. Support for the youngest children will ideally include developmental assessment to help determine appropriate ‘next steps’, but regular liaison or joint clinics with the Specialist Teaching team can help ensure synergistic and practical support in accordance with the goals agreed by parents and professionals. Specialist support is required throughout childhood to minimise the risk to children's long-term outcomes and increase the likelihood of successful transition to independent adulthood.
Mike Nussbaum, chairman of Action for Blind People, by chance met the editor of ADC and the authors are grateful for his encouragement to produce this article.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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