Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia

Refractive error is the most common eye disorder worldwide and is a prominent cause of blindness. Myopia affects over 30% of Western populations and up to 80% of Asians. The CREAM consortium conducted genome-wide meta-analyses, including 37,382 individuals from 27 studies of European ancestry and 8,376 from 5 Asian cohorts. We identified 16 new loci for refractive error in individuals of European ancestry, of which 8 were shared with Asians. Combined analysis identified 8 additional associated loci. The new loci include candidate genes with functions in neurotransmission (GRIA4), ion transport (KCNQ5), retinoic acid metabolism (RDH5), extracellular matrix remodeling (LAMA2 and BMP2) and eye development (SIX6 and PRSS56). We also confirmed previously reported associations with GJD2 and RASGRF1. Risk score analysis using associated SNPs showed a tenfold increased risk of myopia for individuals carrying the highest genetic load. Our results, based on a large meta-analysis across independent multiancestry studies, considerably advance understanding of the mechanisms involved in refractive error and myopia.

Severe visual impairment and blindness in children in the UK

BACKGROUND

Prevention of visual impairment and blindness in childhood is an international priority. However, many countries do not have contemporary information about incidence and causes, from which the scope and priorities for prevention and treatment can be identified.

METHODS

In the UK, children aged younger than 16 years newly diagnosed with severe visual impairment or blindness (SVI/BL, WHO criteria) during 2000 were identified through national active surveillance schemes in ophthalmology and paediatrics. From these data, we calculated yearly age-group specific incidence and cumulative incidence. Causes were classified by the anatomical site or sites affected and by timing of the insult or insults and causal factors, where known.

FINDINGS

Of 439 newly diagnosed children, 336 (77%) had additional non-ophthalmic disorders or impairments (SVI/BL plus). Total yearly incidence was highest in the first year of life, being 4.0 (95% CI 3.6-4.5) per 10000, with a cumulative incidence by 16 years of age of 5.9 (5.3-6.5) per 10000. 10% (44) of all children died within 1 year of diagnosis of blindness. Prenatal causal factors affected 61% (268) of children, with perinatal or neonatal and childhood factors each affecting 18% (77). Incidence and causes varied with presence of non-ophthalmic impairments or disorders, birthweight, and ethnic origin. At least 75% (331) of children had disorders that were neither potentially preventable nor treatable, with current knowledge.

INTERPRETATION

Severe visual impairment and blindness in childhood in the UK is more common, occurs more frequently in the context of complex non-ophthalmic impairments, and has greater associated mortality, than previously assumed. An increased rate in children of low birthweight and from ethnic minority groups, together with the observed diversity and complexity of the causes, reflect recent secular changes in the population at risk, specific risk factors, and strategies available for treatment.

Genome-wide association meta-analysis highlights light-induced signaling as a driver for refractive error

Refractive errors, including myopia, are the most frequent eye disorders worldwide and an increasingly common cause of blindness. This genome-wide association meta-analysis in 160,420 participants and replication in 95,505 participants increased the number of established independent signals from 37 to 161 and showed high genetic correlation between Europeans and Asians (>0.78). Expression experiments and comprehensive in silico analyses identified retinal cell physiology and light processing as prominent mechanisms, and also identified functional contributions to refractive-error development in all cell types of the neurosensory retina, retinal pigment epithelium, vascular endothelium and extracellular matrix. Newly identified genes implicate novel mechanisms such as rod-and-cone bipolar synaptic neurotransmission, anterior-segment morphology and angiogenesis. Thirty-one loci resided in or near regions transcribing small RNAs, thus suggesting a role for post-transcriptional regulation. Our results support the notion that refractive errors are caused by a light-dependent retina-to-sclera signaling cascade and delineate potential pathobiological molecular drivers.

Meta-analysis of 542,934 subjects of European ancestry identifies new genes and mechanisms predisposing to refractive error and myopia

Refractive errors, in particular myopia, are a leading cause of morbidity and disability worldwide. Genetic investigation can improve understanding of the molecular mechanisms that underlie abnormal eye development and impaired vision. We conducted a meta-analysis of genome-wide association studies (GWAS) that involved 542,934 European participants and identified 336 novel genetic loci associated with refractive error. Collectively, all associated genetic variants explain 18.4% of heritability and improve the accuracy of myopia prediction (area under the curve (AUC) = 0.75). Our results suggest that refractive error is genetically heterogeneous, driven by genes that participate in the development of every anatomical component of the eye. In addition, our analyses suggest that genetic factors controlling circadian rhythm and pigmentation are also involved in the development of myopia and refractive error. These results may enable the prediction of refractive error and the development of personalized myopia prevention strategies in the future.

A genome-wide association study for myopia and refractive error identifies a susceptibility locus at 15q25

Myopia and hyperopia are at opposite ends of the continuum of refraction, the measure of the eye's ability to focus light, which is an important cause of visual impairment (when aberrant) and is a highly heritable trait. We conducted a genome-wide association study for refractive error in 4,270 individuals from the TwinsUK cohort. We identified SNPs on 15q25 associated with refractive error (rs8027411, P = 7.91 × 10⁻⁸). We replicated this association in six adult cohorts of European ancestry with a combined 13,414 individuals (combined P = 2.07 × 10⁻⁹). This locus overlaps the transcription initiation site of RASGRF1, which is highly expressed in neurons and retina and has previously been implicated in retinal function and memory consolidation. Rasgrf1(-/-) mice show a heavier average crystalline lens (P = 0.001). The identification of a susceptibility locus for refractive error on 15q25 will be important in characterizing the molecular mechanism responsible for the most common cause of visual impairment.

Childhood blindness in India: causes in 1318 blind school students in nine states

It is estimated that at least 200,000 children in India have severe visual impairment or blindness and approximately 15,000 are in schools for the blind. Although this represents a small percentage of the estimated 5 million blind in India, it is significant in terms of 'blind-years'. Strategies to combat childhood blindness require accurate data on the causes to allocate resources to appropriate preventive and curative services. Since socio-economic factors vary in different areas of this industrializing country data should be representative of the country as a whole. This is the first multi-state study to be undertaken in India using the Record for Children with Blindness and Low Vision from the World Health Organization/PBL Programme. A total of 1411 children in 22 schools from nine states in different geographical zones were examined by an ophthalmologist and optometrist. Of these, 1318 children were severely visually impaired or blind (SVI/BL). The major causes of SVI/BL in this study were: (1) corneal staphyloma, scar and phthisis bulbi (mainly attributable to vitamin A deficiency) in 26.4%; (2) microphthalmos, anophthalmos and coloboma in 20.7%; (3) retinal dystrophies and albinism in 19.3%; and (4) cataract, uncorrected aphakia and amblyopia in 12.3%. This mixed pattern of causes lies in an intermediate position between the patterns seen in developing countries and those seen in industrialised countries. The causes identified indicate the importance both of preventive public health strategies and of specialist paediatric ophthalmic and optical services in the management of childhood blindness in India.

Meta-analysis of gene-environment-wide association scans accounting for education level identifies additional loci for refractive error

Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia.

5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study

BACKGROUND

International initiatives to prevent childhood blindness have highlighted the importance of early, effective intervention for congenital and infantile cataract. In the UK, intraocular lens implantation has been widely adopted by surgeons to treat these conditions. However, evidence about the benefits and risks of this technique in different age groups is limited. The IoLunder2 study assessed outcomes following primary intraocular lens implantation in children aged 2 years and younger with congenital or infantile cataract.

METHODS

The IoLunder2 study was a prospective observational cohort study done at 31 sites in the UK and Ireland. Eligible children were aged 2 years or younger who had cataract surgery concurrently with intraocular lens implantation or conventional treatment (aphakic correction with contact lenses or glasses) after cataract surgery between Jan 1, 2009, and Dec 31, 2010. Children with significant ocular comorbidity precluding lens implantation, defined by the presence of complex persistent fetal vasculature, other ocular structural anomalies, severe microcornea (horizontal corneal diameter <9·5 mm), or severe microphthalmos (axial length <16 mm), were excluded from the analysis of the key outcomes. Postoperative visual rehabilitation was assessed at 1, 3, and 5 years after surgery with a 4m logarithm of the minimum angle of resolution (logMAR) notation test. Best corrected visual outcome (acuity) overall was assessed 5 years after surgery for children with bilateral and unilateral cataract. We also used multivariable logistic and linear regression to model the association between intraocular lens implantation and outcomes of interest (vision, glaucoma, and visual axis opacity).

FINDINGS

A total of 256 eligible children were recruited; two had incomplete data and were excluded. 158 of the 254 included children (102 [65%] with bilateral cataract and 56 [35%] with unilateral cataract) had no significant ocular morbidity and were analysed for the key outcomes. Primary intraocular lens implantation was done in 88 (56%) of 158 children (50 children with bilateral cataract and 38 children with unilateral cataract). 70 (44%) of 158 children had conventional treatment (52 with bilateral cataract and 18 with unilateral cataract). Overall median visual acuity at 5 years was 0·34 logMAR (IQR 0·20-0·54) for children with bilateral cataract and 0·70 logMAR (IQR 0·3-1·3) in the operated eye for children with unilateral cataract. Primary intraocular lens implantation was not associated with better visual outcome than conventional treatment in children with bilateral cataract (adjusted coefficient -0·1, 95% CI -0·5 to 0·3, p=0·48) or unilateral cataract (adjusted coefficient -0·3, -0·6 to 0·2, p=0·36), or reduced incidence of postoperative glaucoma in children with bilateral cataract (adjusted odds ratio [OR] 0·5, 0·10 to 1·80, p=0·28), but was associated with a five times higher risk of reoperation for visual axis opacity requiring general anaesthesia in children with bilateral cataract (adjusted OR 5·94, 95% CI 2·14-16·47, p=0·001) and a 20 times higher risk in children with unilateral cataract (20·15, 3·01-134·00, p=0·001).

INTERPRETATION

The findings of this cohort study indicate that intraocular lens implantation does not confer better vision or protection against postoperative glaucoma, and conversely increases the risk of requiring early reoperation in children younger than 2 years with bilateral or unilateral cataract. The routine use of intraocular lens implantation in this age group cannot be recommended.

FUNDING

National Institute for Health Research, Ulverscroft Foundation, and the Academy of Medical Sciences.

Anophthalmos, microphthalmos, and typical coloboma in the United Kingdom: a prospective study of incidence and risk

PURPOSE

Anophthalmos, microphthalmos, and typical coloboma (AMC) form an interrelated spectrum of congenital eye anomalies that can cause significant visual loss and cosmetic disfigurement in children. This prospective study of children born in the United Kingdom was undertaken to determine the incidence of AMC diagnosed by ophthalmologists and to explore sociodemographic risks.

METHODS

Recruitment was achieved though an established active surveillance system of U.K. ophthalmologists supported by a new research network of interested specialists, the Surveillance of Eye Anomalies (SEA-UK) Special Interest Group. It started October 1, 2006, and continued over 18 months.

RESULTS

One hundred thirty-five children were newly diagnosed with AMC. Typical colobomatous defects were the commonest phenotype, and anophthalmos was rare (n = 7). Both eyes were affected in 55.5% of the children. The cumulative incidence of AMC by age 16 years was 11.9 per 100,000 (95% CI, 10.9-15.4). Of the children examined, 41.5% had not seen an ophthalmologist by 3 months of age. The incidence in Scotland was nearly double that in England and Wales. The children of Pakistani ethnicity had a 3.7 (95% CI, 1.9-7.5) times higher risk of AMC than did white children. There was some evidence to suggest a higher incidence in the more socioeconomically deprived. The sibling risk ratio was 210 (95% CI, 25-722).

CONCLUSIONS

This is the first prospective study of AMC, and it establishes the frequency across the United Kingdom. Comparisons with data quoted in the literature are difficult because study methodologies differ, but the frequency appears to be lower than that quoted for other developed countries. There are geographic and ethnic variations in incidence that warrant further investigation.

Meeting the needs of parents around the time of diagnosis of disability among their children: evaluation of a novel program for information, support, and liaison by key workers

OBJECTIVE

Key worker programs for families of children with disabilities, to promote information provision, emotional support, and liaisons among different agencies, have long been advocated but not extensively implemented. We report the impact on the experiences of parents and the practices of health care professionals of a novel, hospital-based, key worker service (Community Link Team [CLT]), implemented in the pediatric ophthalmology department of Great Ormond Street Hospital (London, United Kingdom).

DESIGN, SETTING, AND PARTICIPANTS

The CLT included 2 members, 1 of whom was present during the first outpatient assessment by the consultant ophthalmologist of any child newly diagnosed as visually impaired (corrected acuity of 6/18 or worse in the better eye) and accompanied the family during other assessments performed during that visit. A dedicated room was used by the CLT members to spend time with each family after completion of the clinical assessments. The CLT members reiterated and/or clarified clinical information already provided, specifically advised the families about visual stimulation programs and the benefits and purpose of visual impairment certification, and provided information about educational and social services. The same CLT member met the family at subsequent visits to the department and acted as the first point of contact for parents. Parents of children newly diagnosed with visual impairment and/or ophthalmic disorders at Great Ormond Street Hospital participated in a 2-stage study to assess their needs, their views about the processes of care, and their overall satisfaction. The study included a questionnaire survey with 2 standard instruments, ie, the Measure of Processes of Care, specifically developed and used to assess parents' views of the degree to which health services for a range of childhood disorders are family-centered, and the short form of the Client Satisfaction Questionnaire, used to assess overall parental satisfaction or dissatisfaction with services in the preceding year, as in other studies of parental satisfaction with pediatric services. This was followed by in-depth individual interviews with a subsample of parents who returned completed questionnaires. The views of families with experience with the new service (CLT) were compared with those without. The experiences of health care professionals before and after implementation of the service were elicited through group interviews and were compared. We recognized that any differences would be attributable to both the direct effects of the CLT, ie, actual services provided by the team, and indirect effects, ie, broader changes in approaches or practices within the department resulting from shifting roles and responsibilities regarding specific elements of management. Therefore, both the specific tasks/activities undertaken by the CLT and broader changes in practices within the department were identified.

RESULTS

Seventy-nine families from the pre-CLT group and 68 from the post-CLT group (68% and 65% of those invited, respectively) participated in the questionnaire survey, of which 29 and 19 (71% and 79% of those invited), respectively, took part in interviews. The 2 groups were comparable with respect to sociodemographic and clinical characteristics. Parents and health care professionals agreed that the CLT provided important information and facilitated access to specific services, while providing both emotional and social support and facilitating meetings with other families with children with similar conditions. A number of key generic components of the service were identified. First, provision, within the outpatient setting, of a dedicated "quiet room" and office space for key workers was an essential physical requirement. Second, early identification of the key workers as the parents' point of contact was essential; this was achieved in this case by the CLT members attending the first consultation, combined with their detailed debriefing of families at the end of the outpatient visit. Third, the adoption of certain tasks by the key workers, including some previously undertaken by ophthalmologists, helped to define the liaison role of the program. These tasks included discussing the process and benefits of visual impairment certification, contacting the advisory teacher for the visually impaired, and providing written reports to educational and social services; analogous tasks would exist for other disabilities.

CONCLUSIONS

Research on the needs of families of visually impaired children has been limited but indicates that, as with other childhood disabilities, the greatest needs during the critical period around diagnosis are for information, especially about educational and social services, and emotional support from professionals, informal and formal social networks, and support groups. Although not widely implemented or studied, key worker programs for families of visually impaired children, particularly in the context of multidisciplinary visual impairment teams, have been advocated, on the basis of their potential to facilitate coordination of health, educational, and social services. The model of such provision evaluated in this study reflects the fact that it was established as an outpatient service in a tertiary referral center for pediatric ophthalmology in the United Kingdom, with the specific structure and specialized roles for health care professionals that this requires. Different models might be more suitable in other settings in the United Kingdom or elsewhere. However, the important general lessons learned should guide implementation of such services for families of children with other disabilities. The recently launched National Service Framework for Children provides a new context and standards for meeting the needs of disabled children and their families in the United Kingdom and may also guide initiatives elsewhere. The findings of this study support implementation of programs for information provision, support, and liaison by key workers in all specialized centers for the assessment and diagnosis of children with serious visual problems. Implementation of similar services for families with children with other disabilities is likely to be equally valuable.

Risks and outcomes associated with primary intraocular lens implantation in children under 2 years of age: the IoLunder2 cohort study

BACKGROUND/AIMS

To investigate outcomes following cataract surgery with and without primary intraocular lens (IoL) implantation in children under 2 years of age with congenital or infantile cataract.

METHOD

Prospective population based cohort study undertaken through the British Isles Congenital Cataract Interest Group, with systematic data collection on children undergoing surgery in UK and Ireland between January 2009 and December 2010. ORs for the association between IoL implantation and visual acuity, postoperative glaucoma and reoperation at 1 year after surgery were estimated using multivariable regression analysis to control for potential confounders.

RESULTS

Of 221 children, 56/131 with bilateral and 48/90 with unilateral cataract underwent primary IoL implantation. IoL implantation was independently associated with better visual outcome in bilateral (OR 4.6, 95% CI 1.6 to 13.1, p=0.004) but not unilateral disease. IoL use increased the odds of reoperation requiring repeat general anaesthetic (bilateral OR 5.5, p<0.01; unilateral OR 16.7, p<0.01). IoL implantation did not reduce the odds of postoperative glaucoma.

CONCLUSIONS

The use of IoLs in cataract surgery in young children should be critically reassessed, particularly used in settings/communities where close, long-term follow-up is challenging. The absence of visual benefit and the lack of a previously postulated protective effect against postoperative glaucoma serve to question the value of IoLs in unilateral disease. The potential association between IoL use and better early visual outcomes in bilateral disease needs to be balanced against the risk of reoperation and exposure to additional general anaesthetics during a key period of neurodevelopment.

National cross sectional study of detection of congenital and infantile cataract in the United Kingdom: role of childhood screening and surveillance. The British Congenital Cataract Interest Group

OBJECTIVES

To determine the mode of detection and timing of ophthalmic assessment of a nationally representative group of children with congenital and infantile cataract.

DESIGN

Cross sectional study.

SETTING

United Kingdom.

SUBJECTS

All children born in the United Kingdom and aged 15 years or under in whom congenital or infantile cataract was newly diagnosed between October 1995 and September 1996.

MAIN OUTCOME MEASURES

Proportion of cases detected through routine ocular examination and proportion assessed by an ophthalmologist by 3 months and 1 year of age.

RESULTS

Data were complete for 235 (95%) of 248 children identified. Of these, 83 (35%) were detected at the routine newborn examination and 30 (12%) at the 6-8 week examination; 82 children presented symptomatically. 137 (57%) children had been assessed by an ophthalmologist by the age of 3 months but 78 (33%) were not examined until after 1 year of age. In 91 cases the child's carers suspected an eye defect before cataract was diagnosed.

CONCLUSIONS

A substantial proportion of children with congenital and infantile cataract are not diagnosed by 3 months of age, although routine ocular examination of all newborn and young infants is recommended nationally. Strategies to achieve earlier detection through screening and surveillance are required.

Prevalence of and early-life influences on childhood strabismus: findings from the Millennium Cohort Study

BACKGROUND

Strabismus is a common disorder of largely unknown cause reported to occur more frequently in children with neurodevelopmental conditions and in children born prematurely or of low birth weight. Population-based investigation of other potential early-life influences has been limited.

OBJECTIVE

To investigate the prevalence of and the early-life risk factors associated with childhood strabismus.

DESIGN

Cross-sectional analytical study of a nationally representative sample of children participating in the Millennium Cohort Study.

SETTING

United Kingdom.

PARTICIPANTS

A population-based sample of 14 980 children aged 3 years.

MAIN OUTCOME MEASURES

Parental report of "isolated" strabismus and "neurodevelopmental" strabismus (ie, in the context of neurologic disorders), considered separately.

RESULTS

Three hundred forty-three children had strabismus (of whom 20 [5.8%] had neurodevelopmental/neurologic disorders), giving a total weighted prevalence of 2.1% (95% confidence interval, 1.8%-2.4%). In multivariable analysis, the risk of isolated strabismus was reduced in children of nonwhite maternal ethnicity and was increased in those born after an assisted or cesarean delivery and in those who were of low birth weight and preterm (in particular, late preterm). An increased risk of neurodevelopmental strabismus was independently associated with maternal smoking into later pregnancy, maternal illnesses in pregnancy, and decreasing birth weight for gestational age and sex. Socioeconomic status was associated with isolated (inverse relationship) and neurodevelopmental (U-shaped relationship) strabismus.

CONCLUSIONS

Several early-life social and biological factors are associated with strabismus, with differences in patterns between isolated and neurodevelopmental forms. Further collaborative research could explore this hypothesis to identify modifiable risk factors.

A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus

Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease.

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.

Large scale international replication and meta-analysis study confirms association of the 15q14 locus with myopia. The CREAM consortium

Myopia is a complex genetic disorder and a common cause of visual impairment among working age adults. Genome-wide association studies have identified susceptibility loci on chromosomes 15q14 and 15q25 in Caucasian populations of European ancestry. Here, we present a confirmation and meta-analysis study in which we assessed whether these two loci are also associated with myopia in other populations. The study population comprised 31 cohorts from the Consortium of Refractive Error and Myopia (CREAM) representing 4 different continents with 55,177 individuals; 42,845 Caucasians and 12,332 Asians. We performed a meta-analysis of 14 single nucleotide polymorphisms (SNPs) on 15q14 and 5 SNPs on 15q25 using linear regression analysis with spherical equivalent as a quantitative outcome, adjusted for age and sex. We calculated the odds ratio (OR) of myopia versus hyperopia for carriers of the top-SNP alleles using a fixed effects meta-analysis. At locus 15q14, all SNPs were significantly replicated, with the lowest P value 3.87 × 10(-12) for SNP rs634990 in Caucasians, and 9.65 × 10(-4) for rs8032019 in Asians. The overall meta-analysis provided P value 9.20 × 10(-23) for the top SNP rs634990. The risk of myopia versus hyperopia was OR 1.88 (95 % CI 1.64, 2.16, P < 0.001) for homozygous carriers of the risk allele at the top SNP rs634990, and OR 1.33 (95 % CI 1.19, 1.49, P < 0.001) for heterozygous carriers. SNPs at locus 15q25 did not replicate significantly (P value 5.81 × 10(-2) for top SNP rs939661). We conclude that common variants at chromosome 15q14 influence susceptibility for myopia in Caucasian and Asian populations world-wide.

Does amblyopia affect educational, health, and social outcomes? Findings from 1958 British birth cohort

OBJECTIVE

To determine any association of amblyopia with diverse educational, health, and social outcomes in order to inform current debate about population screening for this condition.

DESIGN, SETTING, AND PARTICIPANTS

Comparison of 8432 people with normal vision in each eye with 429 (4.8%) people with amblyopia (childhood unilateral reduced acuity when tested with correction and unaccounted for by eye disease) from the 1958 British birth cohort, with respect to subsequent health and social functioning.

RESULTS

No functionally or clinically significant differences existed between people with and without amblyopia in educational outcomes, behavioural difficulties or social maladjustment, participation in social activities, unintended injuries (school, workplace, or road traffic accidents as driver), general or mental health and mortality, paid employment, or occupation based social class trajectories.

CONCLUSIONS

It may be difficult to distinguish, at population level, between the lives of people with amblyopia and those without, in terms of several important outcomes. A pressing need exists for further concerted research on what it means to have amblyopia and, specifically, how this varies with severity and how it changes with treatment, so that screening programmes can best serve those who have the most to gain from early identification.

Prediction of improved vision in the amblyopic eye after visual loss in the non-amblyopic eye

Amblyopia arises from abnormal visual experiences in early childhood. Improved function of the amblyopic eye after visual loss in the non-amblyopic eye could be a model for residual neural plasticity. We aimed to establish the likelihood of, and predictive factors for, this improvement in function. We identified 254 individuals aged 11 years or older with unilateral amblyopia who were visually impaired after loss of vision in their non-amblyopic eye but had no other disorder affecting their amblyopic eye. 25 (10%) of 254 people had improved visual acuity in their amblyopic eye. These findings suggest there is some plasticity in the visual system of a few visually mature individuals with amblyopia, which warrants further study. Children should remain the focus of detection and treatment.

Visual Function, Social Position, and Health and Life Chances: The UK Biobank Study

IMPORTANCE

The adverse impact of visual impairment and blindness and correlations with socioeconomic position are known. Understanding of the effect of the substantially more common near-normal vision (mild impairment) and associations with social position as well as health and life chances is limited.

OBJECTIVE

To investigate the association of visual health (across the full acuity spectrum) with social determinants of general health and the association between visual health and health and social outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional epidemiologic study was conducted using UK Biobank data from 6 regional centers in England and Wales. A total of 112 314 volunteers (aged 40-73 years) were assessed in June 2009 and July 2010. Data analysis was performed from May 20, 2013, to November 19, 2014.

MAIN OUTCOMES AND MEASURES

Habitual (correction if prescribed) distance visual acuity was used to assign participants to 1 of 8 categories from bilateral normal visual acuity (logMAR, 0.2 or better; Snellen equivalent, 6/9.5 or better) to visual impairment or blindness (logMAR, 0.5 or worse; Snellen equivalent, 6/19 or worse) using World Health Organization and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision taxonomy. Relationships between vision, key social determinants and health and social outcomes (including the main factors that define an individual's life-the social, economic, educational, and employment opportunities and outcomes experienced by individuals during their life course) were examined using multivariable regression.

RESULTS

Of the of 112 314 participants, 61 169 were female (54.5%); mean (SD) age was 56.8 (8.1) years. A total of 759 (0.7%) of the participants had visual impairment or blindness, and an additional 25 678 (22.9%) had reduced vision in 1 or both eyes. Key markers of social position were independently associated with vision in a gradient across acuity categories; in a gradient of increasing severity, all-cause impaired visual function was associated with adverse social outcomes and impaired general and mental health. These factors, including having no educational qualifications (risk ratio [RR], 1.86 [95% CI, 1.69-2.04]), having a higher deprivation score (RR, 1.08 [95% CI, 1.07-1.09]), and being in a minority ethnic group (eg, Asian) (RR, 2.05 [95% CI, 1.83-2.30]), were independently associated with being in the midrange vision category (at legal threshold for driving). This level of vision was associated with an increased risk of being unemployed (RR, 1.55 [95% CI, 1.31-1.84]), having a lower-status job (RR, 1.24 [95% CI, 1.09-1.41]), living alone (RR, 1.24 [95% CI, 1.10-1.39]), and having mental health problems (RR, 1.12 [95% CI, 1.04-1.20]).

CONCLUSIONS AND RELEVANCE

Impaired vision in adults is common, and even near-normal vision, potentially unrecognized without assessment, has a tangible influence on quality of life. Because inequalities in visual health by social position mirror other health domains, inclusion of vision in generic initiatives addressing health inequalities could address the existing significant burden of underrecognized and/or latent visual disability. Longitudinal investigations are needed to elucidate pathophysiologic pathways and target modifiable mechanisms.

Genome-wide association studies of refractive error and myopia, lessons learned, and implications for the future

The investigation of the genetic basis of refractive error and myopia entered a new stage with the introduction of genome-wide association studies (GWAS). Multiple GWAS on many ethnic groups have been published over the years, providing new insight into the genetic architecture and pathophysiology of refractive error. This is a review of the GWAS published to date, the main lessons learned, and future possible directions of genetic studies of myopia and refractive error.

Frequency and Distribution of Refractive Error in Adult Life: Methodology and Findings of the UK Biobank Study

Purpose

To report the methodology and findings of a large scale investigation of burden and distribution of refractive error, from a contemporary and ethnically diverse study of health and disease in adults, in the UK.

Methods

U K Biobank, a unique contemporary resource for the study of health and disease, recruited more than half a million people aged 40–69 years. A subsample of 107,452 subjects undertook an enhanced ophthalmic examination which provided autorefraction data (a measure of refractive error). Refractive error status was categorised using the mean spherical equivalent refraction measure. Information on socio-demographic factors (age, gender, ethnicity, educational qualifications and accommodation tenure) was reported at the time of recruitment by questionnaire and face-to-face interview.

Results

Fifty four percent of participants aged 40–69 years had refractive error. Specifically 27% had myopia (4% high myopia), which was more common amongst younger people, those of higher socio-economic status, higher educational attainment, or of White or Chinese ethnicity. The frequency of hypermetropia increased with age (7% at 40–44 years increasing to 46% at 65–69 years), was higher in women and its severity was associated with ethnicity (moderate or high hypermetropia at least 30% less likely in non-White ethnic groups compared to White).

Conclusions

Refractive error is a significant public health issue for the UK and this study provides contemporary data on adults for planning services, health economic modelling and monitoring of secular trends. Further investigation of risk factors is necessary to inform strategies for prevention. There is scope to do this through the planned longitudinal extension of the UK Biobank study.

Visual impairment and vision-related quality of life in working-age adults: findings in the 1958 British birth cohort

PURPOSE

To describe the prevalence of impaired vision and its relative burden, together with the prevalence of impaired vision-related quality of life (VRQOL), and investigate associations with social outcomes in a contemporary and nationally representative population of working age adults.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

We included 9330 members of the 1958 British birth cohort at age 44 and 45 years.

METHODS

"Habitual" and "best achieved" distance visual acuity in each eye, binocular near vision acuity and stereoacuity (three dimensional/depth perception) were tested during a broader biomedical examination. VRQOL was assessed using the Vision-related Quality of Life Core Measure 1 (VCM1), a validated, 10-item, self-complete instrument. Logistic and proportional odds ordinal logistic regression were used to calculate odds ratios (ORs) of the association of VRQOL with visual acuities and social outcomes.

MAIN OUTCOME MEASURES

Distance, near, and stereo acuities and VRQOL and social outcomes.

RESULTS

Of the 1.3% (124) of those with visual loss that precluded driving, a further 0.75% (70) were visually impaired or severely visually impaired and 0.15% (14) blind, the latter accounting for 19% total population (all ages) burden of blindness. Impairment of VRQOL is strongly associated with impaired distance, near, and stereo vision, as well as with adverse occupational and other social outcomes. However, VRQOL impairment is also sometimes reported with unilateral or mild bilateral visual loss.

CONCLUSIONS

Although impaired vision in working age adults is relatively uncommon, it confers important adverse consequences for the "health and wealth" of the public. This may be captured best by assessment of VRQOL in addition to objective visual function. Ophthalmic disorders occurring or impacting in middle life should be given a higher priority than currently in national and international strategies against avoidable visual disability.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Anophthalmos, microphthalmos, and Coloboma in the United kingdom: clinical features, results of investigations, and early management

PURPOSE

To describe the clinical features of children with anophthalmos, microphthalmos, and typical coloboma (AMC).

DESIGN

Descriptive, observational, cross-sectional study of the United Kingdom.

PARTICIPANTS

A total of 135 children with AMC newly diagnosed over an 18-month period beginning in October 2006.

METHODS

Cases were identified using active surveillance through an established ophthalmic surveillance system. Eligible cases were followed up 6 months after first notification.

MAIN OUTCOME MEASURES

Phenotypic characteristics, both ocular and systemic, clinical investigations, causes, and interventions.

RESULTS

A total of 210 eyes (of 135 children) were affected by AMC, of which 153 had isolated coloboma or coloboma with microphthalmos. The most common colobomatous anomaly was a chorioretinal defect present in 109 eyes (71.2%). Some 44% of children were bilaterally visually impaired. Systemic abnormalities were present in 59.7% of children, with craniofacial anomalies being the most common. Children with bilateral disease had a 2.7 times higher odds (95% confidence interval, 1.3-5.5, P = 0.006) of having systemic involvement than unilaterally affected children. Neurologic imaging was the most frequent investigation (58.5%) performed. Less than one third (30.3%) of the children with microphthalmos had ocular axial lengths measured. Eight children had confirmed genetic mutations. Approximately half (49.2%) of the children required ocular intervention.

CONCLUSIONS

Colobomatous defects were the most common phenotype within this spectrum of anomalies in the United Kingdom. The high frequency of posterior segment colobomatous involvement means that a dilated fundal examination should be made in all cases. The significant visual and systemic morbidity in affected children underlines the importance of a multidisciplinary approach to management.