Improving detection of blindness in childhood: the British Childhood Vision Impairment study

A systematic review of the impact of childhood vision impairment on reading and literacy in education

PURPOSE

This systematic review evaluates current literature on the impact vision impairment has on reading and literacy levels within education.

METHODS

Six databases were searched with inclusion criteria of trials or studies involving children who are blind or vision impaired, and impact on academic or school performance - including reading and literacy. 1262 articles were identified, with 61 papers undergoing full screening. Quality appraisal was performed using Critical Appraisal Skills Program (CASP) and seven articles deemed eligible for inclusion.

RESULTS

Included articles achieved a quality score of over 70 % using the CASP checklists. Direct comparison of articles was not possible due to methodological differences in assessing reading and literacy levels. All seven studies investigated aspects of reading speed, with additional measures of reading performance, such as reading reserve, comprehension, and reading accuracy.

DISCUSSION

Underlying trends highlighted students with a vision impairment do not perform at same level as their normally sighted peers with respect to reading performance - in terms of speed, but not ability. Additionally, early intervention to enhance literacy skills may help improve educational outcomes. Future direction should be aimed at identifying specific obstacles to learning these students face and providing interventions to improve academic outcomes.

Distribution and causes of blindness and severe visual impairment in children at a tertiary referral centre in Rwanda

AIM

To determine the prevalence and the causes of severe visual impairment and blindness (SVI/BL) in children at a tertiary referral centre in Rwanda.

METHODS

In this retrospective study, files of all patients <18 years presenting during the year 2019 at the Kabgayi Eye Unit in Rwanda with SVI/BL (presenting visual acuity of <6/60 Snellen or lack of preferential looking behaviour) in at least one eye were analysed for age, sex, laterality, province of origin and cause of SVI/BL. Causes were categorised according to WHO standard classification.

RESULTS

Out of 3939 children presenting to the clinic, 428 (10.9%) had SVI/BL in at least one eye. 165 (4.2%) patients had bilateral and 263 (6.7%) had unilateral condition. Of patients with BL/SVI, 36.7% were below the age of 6 years. In bilateral BL/SVI, the main causes were cataract (18%), refractive error (18%), keratoconus (13%), congenital eye anomaly (9%), glaucoma (8%), cortical blindness (8%) and retinoblastoma (6%). In unilateral BL/SVI it was trauma (46%), cataract (8%), keratoconus (8%), infectious corneal disease (7%) and retinoblastoma (7%). In preschool children, retinopathy of prematurity accounted for 7% of bilateral BL/SVI. Avoidable BL/SVI accounted for 87% of all cases.

CONCLUSION

The high number of avoidable causes for SVI/BL may be reduced through several cost-effective ways.

Delayed diagnosis of congenital cataract in preterm infants: Findings from the IoLunder2 cohort study

BACKGROUND AND OBJECTIVES

Early detection is critical to achieving optimal outcomes in children with congenital cataract. We hypothesized that detection of congenital cataract in preterm infants would be delayed compared with term/post-term peers due to delayed delivery of whole population child health interventions.

METHODS

Secondary analysis of data using a nested case-control study approach in a prospective population-based cohort study. Inclusion criteria comprised children diagnosed with congenital cataract requiring surgical intervention during the first two years of life in UK and Ireland in 2009 and 2010. Association between late detection (after eight weeks post-natal age, ie outside the neonatal and infant eye national screening programme) of cataract and preterm birth (gestational age less than 37 weeks) was assessed using multivariable logistic regression.

RESULTS

Of 186 children with congenital cataract, 17 children were born preterm (9%, gestational age range 24-37weeks). Neonatal detection occurred in 64/186 (34%), and late detection in 64 children (34%). Late detection was independently associated with premature birth, specifically moderate/late preterm birth (adjusted odds ratio 3.0, 95%CI 1.1 to 8.5).

CONCLUSIONS

Our findings suggest that, despite enhanced eye surveillance being recommended for those born moderate/late preterm (32+ weeks gestational age, ie not eligible for retinopathy of prematurity screening), congenital cataract is not being effectively detected through the routine screening programme for this vulnerable group. It is necessary to improve the effectiveness of the screening programme, and care must be taken to ensure that competing health care needs of preterm children do not prevent universal child health interventions.

Causes of Moderate to Severe Visual Impairment and Blindness Among Children in Integrated Schools for the Blind and Visiting a Tertiary Eye Hospital in Nepal: The Nepal Pediatric Visual Impairment (NPVI) Study

Purpose

To study the causes of moderate and severe visual impairment (VI) and blindness and its changing trends in Nepalese children.

Patients and Methods

A cross-sectional descriptive study was conducted. Participants, aged 7 to 17 years were recruited from integrated schools for the blind and the outpatient department of a tertiary eye hospital in Kathmandu. VI and blindness were categorized according to World Health Organization (WHO) categories and its protocol for eye examination of children with blindness and VI was followed. Findings were compared to former studies from Nepal.

Results

A total of 200 children were included, of whom 45% had moderate VI, 5% had severe VI, and 50% were blind. Mean age of children with VI and blindness was 11.1 (SD = 3.3) and 12.9 (SD = 3) years, respectively. Forty percent of children with VI and 38% of blind children were female. In our study, retina (39%) and whole globe (32%) were the most common anatomical site of involvement in children with VI and blindness, respectively, while cornea was the most common anatomical site of involvement in former studies. Heredity (43%) was the most common etiological factor although in 24.5% of all children, etiology was unknown. In 43.5% of children, blindness and VI was due to avoidable causes.

Conclusion

In relatively many children, the etiology of VI and blindness could be either prevented or treated. Compared to former studies from Nepal, there is a changing trend in the etiology of severe VI and blindness.

The role of screening and surveillance in the detection of childhood vision impairment and blindness in the UK

OBJECTIVE

Understanding pathways to detection for childhood visual impairment (VI) is critical for planning services. We aimed to describe patterns of detection for childhood VI.

DESIGN AND SETTING

Cross-sectional study using data from British Childhood Visual Impairment and Blindness Study 2.

PATIENTS

Children newly diagnosed with VI, severe vision impairment or blindness (SVI/BL)-that is, visual acuity worse than logMAR 0.5 in both eyes-were identified through active surveillance, with data collection at diagnosis and 1 year later.

OUTCOME MEASURE

Method of detection of vision/eyes problem.

RESULTS

784 children (45%, 356 girls) were identified, of whom 313 (40%) had VI, 471 (60%) had SVI/BL. Additional non-ophthalmic disorders or impairments (VI/SVI/BL 'plus'), were diagnosed in 72% (559/784). Of the 784, 173 children were detected through routine screening (22%), 248 through targeted examinations (32%) and 280 through family self-referral (36%). Parents and carers had only reported symptoms in 55% of children who manifested them, with evidence that families living in socioeconomically deprived areas were less likely to report concerns. Paediatricians were the professionals most likely to raise initial suspicion of visual disability.

CONCLUSIONS

Our findings show that targeted screening and surveillance is important for the detection of full spectrum childhood visual impairment (VI/SVI/BL), as a significant proportion of children will not have symptoms, or their parents or carers will not report symptoms. As paediatricians were the professionals most commonly involved in detection, it would be helpful if their core competencies included the skills needed to undertake simple assessments of vision.

Global Prevalence and Causes of Visual Impairment and Blindness in Children: A Systematic Review and Meta-Analysis

Purpose:

To determine the global prevalence and common causes of visual impairment (VI) and blindness in children.

Methods:

In this meta-analysis, a structured search strategy was applied to search electronic databases including PubMed, Scopus, and Web of Science, as well as the list of references in the selected articles to identify all population-based cross-sectional studies that concerned the prevalence of VI and blindness in populations under 20 years of age up to January 2018, regardless of the publication date and language, gender, region of residence, or race. VI was reported based on presenting visual acuity (PVA), uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA) of equal to 20/60 or worse in the better eye. Blindness was reported as visual acuity worse than 20/400 in the better eye.

Results:

In the present study, 5711 articles were identified, and the final analyses were done on 80 articles including 769,720 people from twenty-eight different countries. The prevalence of VI based on UCVA was 7.26% (95% confidence interval [CI]: 4.34%–10.19%), PVA was 3.82% (95% CI: 2.06%–5.57%), BCVA was 1.67% (95% CI 0.97%–2.37%), and blindness was 0.17% (95% CI: 0.13%–0.21%). Refractive errors were the most common cause of VI in the subjects of selected articles (77.20% [95% CI: 73.40%–81.00%]). The prevalence of amblyopia was 7.60% (95% CI: 05.60%–09.10%) and congenital cataract was 0.60% (95% CI: 0.3%–0.9%).

Conclusion:

Despite differences in the definition of VI and blindness, based on PVA, 3.82%, and based on BCVA, 1.67% of the examined samples suffer from VI.

Changing pattern of childhood blindness in eight North-Eastern states and review of the epidemiological data of childhood blindness of India

Purpose:

To assess the causes of visual impairment and blindness in children in all the schools for the blind in eight northeastern states and to determine its temporal trend, and to analyze the result with reference to various regional epidemiological data on childhood blindness in India.

Methods:

Children aged ≤16 years, with a visual acuity of ≤6/18 in the better eye, attending 17 schools for the blind were examined between November 2018 and March 2020. WHO protocol and reporting format was used for the evaluation, diagnosis, and classification of the causes.

Results:

Out of 465 eligible study participants, 93.76% were blind and only 12.26% of causes were avoidable. Anatomical causes of childhood blindness were whole globe (43.2%), cornea (17.20%), optic nerve (12.04%), retina (9.68%), and lens (9.46%). Etiological causes were unknown (52.69%), hereditary (26.02%), intrauterine (15.05%), and 26.08% had blinding congenital ocular abnormality (s). Regional temporal trend revealed a decrease in corneal and childhood causes and an increase in retina, optic nerve, hereditary, and intrauterine causes.

Conclusion:

A constellation of causes were differentiable but matched with the overall emerging trend of childhood blindness in India. Higher corneal, unavoidable, and unknown causes suggest a region-specific action plan for controlling childhood blindness as well as rehabilitation.

Reporting on Australian childhood visual impairment: the first 10 years

BACKGROUND

Visual impairment is rare but has significant impact on the neurobehavioural development and quality of life of children. This paper presents the key findings from the Australian Childhood Vision Impairment Register, which commenced in 2008 to report on children diagnosed with permanent visual impairment.

SUBJECTS/METHODS

Families consent to completing a data form related to their child and for contact with the child's ophthalmologist. Ophthalmologists complete and return a comprehensive data form on the child's primary and secondary ocular diagnoses, associated disabilities and health conditions, visual acuity and visual fields. Data is stored on a secure database and anonymised data is available to researchers and for planning purposes.

RESULTS

Nine-hundred four children and their families provided informed consent for participation, with 57% males and 43% females. Most children spoke English in their home. Eighty-three percent of children were born full term, with a birth weight of >2500 g (81%). Children were commonly suspected to have visual impairment by a parent, with 68% of families receiving a diagnosis of visual impairment by their child's first birthday. The most common primary diagnoses were retinal dystrophy (17%), CVI (15%) and Albinism (11%). A secondary diagnosis of infantile nystagmus occurred in 33% of children. Additional disabilities and/or developmental delay were reported for 44% of children. Corrected binocular visual acuity was reported for 75% of children, with moderate visual impairment being most common.

CONCLUSIONS

These findings contribute to knowledge of rare diseases affecting the eye and visual pathway and represent Australian childhood visual impairment.

Behavioural Features of Cerebral Visual Impairment Are Common in Children With Down Syndrome

It is widely recognised that children with Down syndrome have a broad range and a high prevalence of visual deficits and it has been suggested that those with Down syndrome are more likely to exhibit visual perception deficits indicative of cerebral visual impairment. This exploratory study aims to determine the prevalence of behavioural features suggestive of cerebral visual impairment (CVI) occurring with Down syndrome and whether the visual problems can be ascribed to optometric factors. A cohort of 226 families of children with Down syndrome (trisomy 21), aged 4–17, were invited to participate in a validated question inventory, to recognise visual perception issues. The clinical records of the participants were then reviewed retrospectively. A five-question screening instrument was used to indicate suspected CVI. The majority of the 81 families who responded to the questionnaire reported some level of visual perceptual difficulty in their child. Among this cohort, the prevalence of suspected CVI as indicated by the screening questionnaire was 38%. Only ametropia was found to have a significant association with suspected CVI, although this increased the correct prediction of suspected CVI outcome by only a small amount. Results suggest that children with Down syndrome are more likely to experience problems consistent with cerebral visual impairment, and that these may originate from a similar brain dysfunction to that which contributes to high levels of ametropia and failure to emmetropise. It is important that behavioural features of CVI are recognised in children with Down syndrome, further investigations initiated and appropriate management applied.

Causes of vision impairment and blindness among children in schools for the blind in South Indian States of Andhra Pradesh and Telangana

Purpose:

To study the causes of severe vision impairment (SVI) and blindness among children in Andhra Pradesh (AP) and Telangana State (TS) in South India.

Methods:

A total of 299 children from 10 schools for the blind were examined between January and December 2017. The schools were chosen from 3 districts of AP (Guntur, Krishna and West Godavari) and 2 districts of TS (Adilabad and Mahabubnagar). The World Health Organization Prevention of Blindness' eye examination protocol for children with blindness or visual impairment (VI) was followed.

Results:

Based on presenting visual acuity (PVA), 248 children (82.9%) were blind, 16 children (5.3%) had SVI, 18 (6%) had moderate VI, and 17 (5.7%) were normal. The most common anatomical cause of blindness or SVI was whole globe anomaly (32%), followed by an abnormality in the retina and vitreous (26.6%). While whole globe anomalies were high both in AP (33.8%) and TS (21.6%), lens-related pathologies were higher in TS (29.7%) and retina-related abnormalities were higher in AP (29.3%). The most common cause was related to heredity (40.5%). Etiology was unknown in 33.5% of cases. Overall, 37.1% of the causes were avoidable. In AP, 33.4% were avoidable whereas in TS nearly 60% were avoidable.

Conclusion:

Whole globe anomaly constitutes a major cause of SVI and blindness, especially in AP. Lens-related pathologies were higher in TS. Nearly 40% of the causes were avoidable. Hence, robust screening methods and strategies must be established for timely intervention to reduce the burden on VI in children.

Causes of severe visual impairment in infants and methods of management

OBJECTIVES

To examine the causes of severe visual impairment (SVI) in infants below the age of 2 years and to review management methods.

METHODS

The data of 2657 patients followed between January 2014 and July 2019 were reviewed, and 148 (5.6%) infants who had SVI were enrolled. Data including age, gender, affected anatomical site, diagnosis, presence of any non-ophthalmological deficiencies, and methods of management were reviewed. The diagnoses were investigated in the categories of avoidable and unavoidable basis. The methods of management were analysed from the perspective of low vision habilitation.

RESULTS

The mean age at first eye examination was 6.61 ± 5.25 months, and 84 (56.7%) infants were male. Of the 148 infants, 69 (46.6%) were premature. Cerebral visual impairment (CVI) was the most common diagnosis in both preterm (39.1%) and term (11.4%) infants. Delayed visual maturation, optic nerve pathologies, oculocutaneous albinism, and congenital cataract were the other frequent causes. The rate of multiple disabilities was 30% in the whole group and 94% in infants with CVI. Most of the babies had a normal-appearing globe (43.3%). Retina was affected in 23.7% of the infants. Avoidable causes were identified in 79.7% of the infants. The used methods of management were optic interventions, visual stimulation therapy, medical and/or surgical treatment.

CONCLUSIONS

CVI was found the most common cause of SVI in both preterm and term-born infants, and the higher rate of multiple disabilities in these infants was remarkable. Optic interventions and visual stimulation therapy were the most common methods of management.

Final versus referral diagnosis of childhood visual impairment in an Italian tertiary low vision rehabilitation centre

PURPOSE

To compare the final diagnosis of the causes of low vision in children attending a tertiary rehabilitation centre for visually impaired children versus referral diagnosis.

METHODS

Retrospective review of clinical charts of all children referred to the Robert Hollman Foundation, a tertiary centre for visually impaired children, between January 2010 and June 2011. The following clinical data were analysed: entry diagnosis made by the referral ophthalmologist and final diagnosis made at Robert Hollman Foundation based on a complete ophthalmic evaluation.

RESULTS

Ninety-two consecutive children (mean age = 2.37 ± 1.98 years, range = 0-9) were included. A referral diagnosis was retrieved in 76 cases (82.6%), including cerebral visual impairment (14.1%), retinopathy of prematurity (14.1%), hereditary retinal diseases (10.9%), nystagmus (8.7%) and other rarer diseases (34.8%). In the remaining 16 children (17.4%), a precise referral diagnosis was unavailable. Final clinical diagnosis made at Robert Hollman Foundation was normal visual function in 8.7%, cerebral visual impairment in 30.4%, retinopathy of prematurity in 10.9%, hereditary retinal disease in 9.8% and other in 40.2%. In 17 cases (18.5%), the diagnosis made at the Robert Hollman Foundation did not confirm the entry diagnosis. Among patients where measurement of visual acuity was possible (84), 66.7% were blind or seriously visual impaired, and the main causes were cerebral visual impairment (32.1%) and retinopathy of prematurity (16.1%).

CONCLUSION

The most frequent diseases were cerebral visual impairment, retinopathy of prematurity and hereditary retinal diseases. Approximately one-third of referred children had not a correct diagnosis at baseline. The activity of an ophthalmic tertiary centre is essential to offer a precise diagnosis to visually impaired (sometimes with other deficits) children.

Refractive error and ocular findings among infants and young children with severe problem behavior and developmental disabilities

The prevalence of refractive error and ocular disorders among infants and young children with severe behavioral problems and developmental disorders is not well defined, particularly in developing countries. We performed a retrospective review of ophthalmic examinations performed during a National Institutes of Health-funded cohort study of very young children in Peru with behavioral problems and at risk for developmental disorders. 222 children between the ages of 0 and 4 years (mean 2.2 ± 0.9 years) were examined and 100 (45.0%) had an abnormal ocular exam. Overall, the prevalence of refractive error was 33.3%, nystagmus was 12.2%, and strabismus was 10.9%. Among children with Down syndrome, refractive error ranged from 46.2% at age 2 to 85.7% at age 4. Refractive error and ocular disorders are highly prevalent even at a young age in children with behavioral problems and developmental disorders. Much of the visual impairment in this population is treatable; early identification and intervention can have a lifelong positive impact on neurodevelopment.

Sexual assaults in individuals with visual impairment: a cross-sectional study of a Norwegian sample

OBJECTIVE

To examine the prevalence of sexual assaults among individuals with visual impairment (VI) compared with the general population and to investigate the association between sexual assault and outcomes of self-efficacy and life satisfaction.

DESIGN

Cross-sectional interview-based study conducted between February and May 2017.

PARTICIPANTS

A probability sample of adults with VI (≥18 years) who were members of the Norwegian Association of the Blind and Partially Sighted. A total of 736 (61%) members participated, of whom 55% were of female gender. We obtained norm data for sexual assaults from a representative survey of the general Norwegian population.

OUTCOME MEASURES

Sexual assaults (Life Event Checklist for DSM-5), self-efficacy (General Self-Efficacy Scale) and life satisfaction (Cantril's Ladder of Life Satisfaction).

RESULTS

The prevalence of sexual assaults (rape, attempted rape and forced into sexual acts) in the VI population was 17.4% (95% CI 14.0 to 21.4) among women and 2.4% (95% CI 1.2 to 4.7) among men. For women, the VI population had higher rates of sexual assaults across age strata than the general population. For men, no significant differences were found. In the population of people with VI, the risk of sexual assault was greater for those having other impairments in addition to the vision loss. Individuals with VI who experienced sexual assaults had lower levels of self-efficacy (adjusted relative risk (ARR): 0.18, 95% CI 0.05 to 0.61) and life satisfaction (ARR: 0.31, 95% CI 0.19 to 0.50) than others.

CONCLUSIONS

The risk of experiencing sexual assault appears to be higher in individuals with VI than in the general population. Preventive measures as well as psychosocial care for those who have been exposed are needed.

Magnitude and Temporal Trends in Avoidable Blindness in Children (ABC) in India

The World Health Organization estimates that 19 million children are visually impaired, among whom, 1.4 million are blind. Childhood blindness is an excellent indicator of the state of child health and primary care services in a country. Childhood blindness is important not just due to the number of children blind but also because the number of years that the surviving child has to live with blindness (blind years lived). Childhood blindness is next only to adult cataract in terms of the number of blind person years lived. Under-five mortality rates have been used as a proxy measure to compute the prevalence of childhood blindness in low and middle income countries due to limitations of other methods of data collection. In India, it is estimated that there are 0.8 blind for 1000 children. Whole globe lesions, corneal scarring, retinal pathology and afflictions of the lens are important anatomical sites in children. Causes operating in childhood and hereditary causes are important in etiology of childhood blindness. In 38.2%-68.4% cases across the region, a specific cause of blindness could not be identified in South Asia. The proportion of blindness that can be prevented or treated (avoidable) in children is less than 50%. Therefore a comprehensive eye care system needs to be in place to cater to the needs of children with avoidable and those with incurable blindness. Early detection and prompt management are critical for success of programs targeting avoidable blindness in children.

Trends in Visual Health Inequalities in Childhood Through Associations of Visual Function With Sex and Social Position Across 3 UK Birth Cohorts

Importance

Despite the existing country-specific strategies tackling social inequalities in visual health in adults, little is known about trends in visual function in childhood and its association with social position.

Objective

To investigate the distribution of childhood visual function in the United Kingdom and associations with early-life social position between 1961 and 1986, a period of significant social change.

Design, Setting, and Participants

Longitudinal cohort study using harmonized data sets from the British 1946, 1958, and 1970 national birth cohorts. In total, 14 283 cohort members with complete data on visual acuity at age 15 or 16 years, measured in 1961, 1974, and 1986, respectively, for each cohort, and social position were assessed.

Main Outcomes and Measures

Using habitual distance visual acuity (with correction if prescribed), participants were assigned to a visual function category ranging from bilateral normal to visual impairment/severe visual impairment/blindness (International Statistical Classification of Diseases, Tenth Revision, Clinical Modification). Distribution of visual function over time and associations with social position (risk ratios [RRs] and 95% confidence intervals) were analyzed.

Results

Complete data were available for 3152 participants (aged 15 years; 53% boys [n = 1660]) in the 1946 Medical Research Council National Survey of Health and Development, 6683 participants (aged 16 years; 51% boys [n = 3420]) in the 1958 National Child Development Study, and 4448 participants (aged 16 years; 48% boys [n = 2156]) in the 1970 British Birth Cohort Study. The proportion of children with bilateral normal vision decreased by 1.3% (95% CI, -5.1% to 2.7%) in 1974 and 1.7% (95% CI, -5.9% to 2.7%) in 1986. The risk of overall impaired vision increased by 1.20 times (95% CI, 1.01-1.43) and the risk of visual impairment/severe visual impairment/blindness by 1.75 times (95% CI, 1.03-2.98) during this period. Girls were consistently at increased risk of all vision impairment categories. Higher social position at birth and in childhood was associated with reduced risk of visual impairment/severe visual impairment/blindness (RR, 0.58; 95% CI, 0.20-1.68) and unilateral impairment (RR, 0.89; 95% CI, 0.72-1.11), respectively.

Conclusions and Relevance

Our study provides evidence of temporal decline in childhood visual function between 1961 and 1986. Despite the limited power of the analysis owing to the small sample size of those with impaired vision, we found an emergence of a contribution of sociodemographic status to the cohort effect that may be the antecedent of the current picture of childhood blindness. Equally, early-life social position may also have contributed to the current social patterning in visual function in older adults in the United Kingdom. These findings highlight the potential value of targeting children in national ophthalmic public policies tackling inequalities.

Epidemiology of blindness in children

An estimated 1.4 million of the world's children are blind. A blind child is more likely to live in socioeconomic deprivation, to be more frequently hospitalised during childhood and to die in childhood than a child not living with blindness. This update of a previous review on childhood visual impairment focuses on emerging therapies for children with severe visual disability (severe visual impairment and blindness or SVI/BL).For children in higher income countries, cerebral visual impairment and optic nerve anomalies remain the most common causes of SVI/BL, while retinopathy of prematurity (ROP) and cataract are now the most common avoidable causes. The constellation of causes of childhood blindness in lower income settings is shifting from infective and nutritional corneal opacities and congenital anomalies to more resemble the patterns seen in higher income settings. Improvements in maternal and neonatal health and investment in and maintenance of national ophthalmic care infrastructure are the key to reducing the burden of avoidable blindness. New therapeutic targets are emerging for childhood visual disorders, although the safety and efficacy of novel therapies for diseases such as ROP or retinal dystrophies are not yet clear. Population-based epidemiological research, particularly on cerebral visual impairment and optic nerve hypoplasia, is needed in order to improve understanding of risk factors and to inform and support the development of novel therapies for disorders currently considered 'untreatable'.

Field testing a draft version of the UNICEF/Washington Group Module on child functioning and disability. Background, methodology and preliminary findings from Cameroon and India

Background

Global child disability data are generally non-comparable, comprising different tools, methodologies and disability definitions. UNICEF and The Washington Group on Disability Statistics (WG) have developed a new tool on child functioning and disability to address this need.

Aims

The aim of this paper is to describe the development of the new module, and to present an independent field test of the draft module in two contrasting settings.

Methods

UNICEF and the WG developed a parent-reported survey module to identify children aged 2-17 years with functional difficulties in population-based surveys through: review of existing documentation, consultation with experts and cognitive testing. A field test of the draft module was undertaken in Cameroon and India within a population-based survey. Functional limitation in each of 14 domains was scored on a scale comprising "no difficulty", "some difficulty", "a lot of difficulty" and "cannot do".

Results

In all, 1713 children in Cameroon and 1101 children in India were assessed. Sixty-four percent of children in Cameroon and 35% of children in India were reported to have at least some difficulty in one or more domain. The proportion reported to have either "a lot of difficulty" or "cannot do" was 9% in Cameroon and 4% in India. There were no significant differences in reported functional difficulties by sex but children aged 2-4 were reported to have fewer functional difficulties of any kind compared with older children in both countries.

Conclusion

Comparable estimates were generated between the two countries, providing an initial overview of the tool's outputs. The continued development of this standardised questionnaire for the collection of robust and reliable data on child disability is essential.

The prevalence of neuromuscular disease in the paediatric population in Yorkshire, UK; variation by ethnicity and deprivation status

AIM

Previous studies suggest a higher prevalence of neurological disease within certain ethnic communities, but have not specifically considered neuromuscular diseases (NMDs). The aim of this study was to calculate the prevalence and relationship of NMDs to ethnicity and deprivation status.

METHOD

We undertook a retrospective case-note review of those younger than 16 years with a confirmed diagnosis of NMD in a single centre in Yorkshire in 2010.

RESULTS

Two-hundred and sixty-one cases were included. The population (0-16y) in Yorkshire was 707 961. The overall prevalence was 36.9 per 100 000 (95% confidence interval [CI] 34.6-39.1). Dystrophin-related muscle disease was the most common condition, with a prevalence of 16.9 per 100 000 males (95% CI 14.7-19.1). There was a significant difference between ethnic groups, with a total NMD prevalence of 91.2 per 100 000 (95% CI 81.6-100.7) in the South Asian ethnic group compared with 28.7 per 100 000 (95% CI 26.4-30.9) in the White group. Prevalence of non-dystrophin-related NMDs was four times higher in South Asian than in White children. There was a linear relation between increased prevalence and increased deprivation.

INTERPRETATION

This study confirms higher levels of NMD, particularly recessively inherited NMDs within the South Asian population, as well as a link with higher deprivation. This has implications for service provision and resource allocation.

Mental health of children with vision impairment at 11 years of age

AIM

The purpose of the study was to compare the risk of psychiatric disturbance among sighted and vision-impaired children aged 11 years.

METHOD

Scores from the parent and teacher versions of the Strengths and Difficulties Questionnaire (SDQ) were used to compare sighted children with: vision-impaired children; vision-impaired children with no other reported disabilities or special educational needs; and children with vision impairment and additional disabilities or special educational needs. Logistic regression was used to measure the associations between the independent variables and SDQ scores, and to test for significance of the observed differences.

RESULTS

Both parents and teachers scored vision-impaired children significantly higher on the SDQ compared with sighted children (p≤0.000) and a significantly higher proportion of the vision-impaired children had SDQ scores in the abnormal range (p≤0.000). Children with vision impairment and other disabilities or special educational needs were rated as being at greatest risk of psychiatric disorder by both parents (30%) and teachers (22%).

INTERPRETATION

Vision impairment among children as young as 11 years of age is associated with an increased risk of psychiatric disorder.

Support for infants and young people with sight loss: a qualitative study of sight impairment certification and referral to education and social care services

OBJECTIVES

To examine the experience of infants, children and their parents, the role of ophthalmologists and other health, social care and education professionals in the certification and registration processes and examine the relationship between certification and referrals and pathways to support.

DESIGN

Qualitative study.

SETTING

Telephone interviews with health and, social care professionals, qualified teachers of children and young people with vision impairment (QTVIs) and parents of infants/children in England.

PARTICIPANTS

52 health, social care and education professionals who are part of the certification or registration process. 26 parents of infants and children with vision impairment.

RESULTS

Referrals to education do not require a Certificate of Vision Impairment (CVI); however, the majority of parents received support from education and social services only after an offer of the CVI, which was often dependent on having a formal diagnosis. Parents stated they wanted support sooner, particularly parents of children with additional complex needs who experienced longer delays. Areas with multidisciplinary teams and support roles such as eye clinic liaison officers (ECLOs) appeared to have more reliable referral pathways.

CONCLUSIONS

For infants and children with vision impairment, there should be a consistent mechanism for triggering education and social care support even with uncertainty about diagnosis and/or prognosis. All professionals involved in the certification and registration processes (ophthalmologists, optometrists, ECLOs, orthoptists, social workers, QTVIs) can better communicate the value and benefits of certification and registration.

Whole-population vision screening in children aged 4-5 years to detect amblyopia

Amblyopia is a neurodevelopmental disorder that affects at least 2% of most populations and can lead to permanently reduced vision if not detected and treated within a specific period in childhood. Whole-population screening of children younger than 5 years is applied in many countries. The substantial diversity in existing programmes reflects their heterogeneous implementation in the absence of the complete evidence base that is now a pre-requisite for instituting screening. The functional importance of amblyopia at an individual level is unclear as data are scarce, but in view of the high prevalence the population-level effect might be notable. Screening of all children aged 4-5 years (eg, at school entry) confers most benefit and addresses inequity in access to timely treatment. Screening at younger ages is associated with increased risk of false-positive results, and at older ages with poor outcomes for children with moderate to severe amblyopia. We suggest that the real-life adverse effects of amblyopia should be characterised and screening and diagnosis should be standardised.

Epidemiology, aetiology and management of visual impairment in children

An estimated 19 million of the world's children are visually impaired, while 1.4 million are blind. Using the UK as a model for high income countries, from a population-based incidence study, the annual cumulative incidence of severe visual impairment/blindness (SVL/BL) is estimated to be 6/10 000 by age 15 years, with the incidence being highest in the first year of life. The population of visually impaired children within high, middle and lower income countries differ considerably between and within countries. The numerous and mainly uncommon disorders which can cause impaired vision result in heterogeneous population which includes a substantial proportion (for SVI/BL, the majority) of children with additional systemic disorders or impairments whose needs differ substantially from those with isolated vision impairment. Paediatricians and other paediatric professionals have a key role in early detection and multidisciplinary management to minimise the impact of visual impairment (VI) in childhood.

New systematic review methodology for visual impairment and blindness for the 2010 Global Burden of Disease study

PURPOSE

To describe a systematic review of population-based prevalence studies of visual impairment (VI) and blindness worldwide over the past 32 years that informs the Global Burden of Diseases, Injuries and Risk Factors Study.

METHODS

A systematic review (Stage 1) of medical literature from 1 January 1980 to 31 January 2012 identified indexed articles containing data on incidence, prevalence and causes of blindness and VI. Only cross-sectional population-based representative studies were selected from which to extract data for a database of age- and sex-specific data of prevalence of four distance and one near vision loss categories (presenting and best-corrected). Unpublished data and data from studies using rapid assessment methodology were later added (Stage 2).

RESULTS

Stage 1 identified 14,908 references, of which 204 articles met the inclusion criteria. Stage 2 added unpublished data from 44 rapid assessment studies and four other surveys. This resulted in a final dataset of 252 articles of 243 studies, of which 238 (98%) reported distance vision loss categories. A total of 37 studies of the final dataset reported prevalence of mild VI and four reported near VI.

CONCLUSION

We report a comprehensive systematic review of over 30 years of VI/blindness studies. While there has been an increase in population-based studies conducted in the 2000s compared to previous decades, there is limited information from certain regions (eg, Central Africa and Central and Eastern Europe, and the Caribbean and Latin America), and younger age groups, and minimal data regarding prevalence of near vision and mild distance VI.