Jugnoo S. Rahi

Increasing Prevalence of Myopia in Europe and the Impact of Education

Purpose To investigate whether myopia is becoming more common across Europe and explore whether increasing education levels, an important environmental risk factor for myopia, might explain any temporal trend. Design Meta-analysis of population-based, cross-sectional studies from the European Eye Epidemiology (E3) Consortium. Participants The E3 Consortium is a collaborative network of epidemiological studies of common eye diseases in adults across Europe. Refractive data were available for 61 946 participants from 15 population-based studies performed between 1990 and 2013; participants had a range of median ages from 44 to 78 years. Methods Noncycloplegic refraction, year of birth, and highest educational level achieved were obtained for all participants. Myopia was defined as a mean spherical equivalent ≤−0.75 diopters. A random-effects meta-analysis of age-specific myopia prevalence was performed, with sequential analyses stratified by year of birth and highest level of educational attainment. Main Outcome Measures Variation in age-specific myopia prevalence for differing years of birth and educational level. Results There was a significant cohort effect for increasing myopia prevalence across more recent birth decades; age-standardized myopia prevalence increased from 17.8% (95% confidence interval [CI], 17.6–18.1) to 23.5% (95% CI, 23.2–23.7) in those born between 1910 and 1939 compared with 1940 and 1979 (P = 0.03). Education was significantly associated with myopia; for those completing primary, secondary, and higher education, the age-standardized prevalences were 25.4% (CI, 25.0–25.8), 29.1% (CI, 28.8–29.5), and 36.6% (CI, 36.1–37.2), respectively. Although more recent birth cohorts were more educated, this did not fully explain the cohort effect. Compared with the reference risk of participants born in the 1920s with only primary education, higher education or being born in the 1960s doubled the myopia prevalence ratio–2.43 (CI, 1.26–4.17) and 2.62 (CI, 1.31–5.00), respectively—whereas individuals born in the 1960s and completing higher education had approximately 4 times the reference risk: a prevalence ratio of 3.76 (CI, 2.21–6.57). Conclusions Myopia is becoming more common in Europe; although education levels have increased and are associated with myopia, higher education seems to be an additive rather than explanatory factor. Increasing levels of myopia carry significant clinical and economic implications, with more people at risk of the sight-threatening complications associated with high myopia.

Genome-wide meta-analysis of myopia and hyperopia provides evidence for replication of 11 loci

Refractive error (RE) is a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and its axial length that causes object images to be focused off the retina. The two major subtypes of RE are myopia (nearsightedness) and hyperopia (farsightedness), which represent opposite ends of the distribution of the quantitative measure of spherical refraction. We performed a fixed effects meta-analysis of genome-wide association results of myopia and hyperopia from 9 studies of European-derived populations: AREDS, KORA, FES, OGP-Talana, MESA, RSI, RSII, RSIII and ERF. One genome-wide significant region was observed for myopia, corresponding to a previously identified myopia locus on 8q12 (pu200a=u200a1.25×10−8), which has been reported by Kiefer et al. as significantly associated with myopia age at onset and Verhoeven et al. as significantly associated to mean spherical-equivalent (MSE) refractive error. We observed two genome-wide significant associations with hyperopia. These regions overlapped with loci on 15q14 (minimum p valueu200a=u200a9.11×10−11) and 8q12 (minimum p value 1.82×10−11) previously reported for MSE and myopia age at onset. We also used an intermarker linkage- disequilibrium-based method for calculating the effective number of tests in targeted regional replication analyses. We analyzed myopia (which represents the closest phenotype in our data to the one used by Kiefer et al.) and showed replication of 10 additional loci associated with myopia previously reported by Kiefer et al. This is the first replication of these loci using myopia as the trait under analysis. “Replication-level” association was also seen between hyperopia and 12 of Kiefer et al.s published loci. For the loci that show evidence of association to both myopia and hyperopia, the estimated effect of the risk alleles were in opposite directions for the two traits. This suggests that these loci are important contributors to variation of refractive error across the distribution.

Perimetry in Children: Survey of Current Practices in the United Kingdom and Ireland

Purpose: Visual fields are key functional outcome measures in children with a variety of ophthalmologic disorders. However, reliably assessing fields in children is challenging. We report the findings of a survey of current practices of perimetry in children in the United Kingdom and Ireland. Methods: An electronic questionnaire was sent to Orthoptic Service Heads in July 2008. Respondents were asked for comments regarding visual field testing in children as well as details of the volume and type of perimetry performed in their units, over a 1-year period. Results: Of the 98 (62%) completed questionnaires, 16 departments reported not testing visual fields in children. In total 3675 subjects under 16 years of age were reported to have undergone perimetry in 1 year, most in units with a ≥ 50% pediatric caseload for orthoptics. A total of 42% of units used static perimetry alone, 11% kinetic, and 47% used a combination of both. Conclusion: High numbers of visual field tests are carried out in children in the UK and Ireland annually. Automated perimetry is used predominantly, despite the underlying algorithms having been developed for adult populations. Thus there is a clear need for more research, to ensure that evolving management practices are informed by understanding of the diagnostic accuracy and value of perimetry in children.

Vision Screening in Children: Why and How?

Life Course Epidemiology and Biostatistics section, UCL Institute of Child Health, London, UK, NIHR Moorfields Biomedical Research Centre/Moorfields Eye Hospital NHS Foundation Trust, London, UK, Ulverscroft Vision Research Group, UCL Institute of Child Health, London, UK, Great Ormond Street Hospital/Institute of Child Health Biomedical Research Centre, London, UK, and Institute of Ophthalmology, University College London, London, UK

Childhood Eye Disorders and Visual Impairment

Children with visual and ocular disorders form a heterogeneous group with differing ocular and systemic disorders, and visual, other sensory, motor and global developmental impairments which impact the level and type of support they need in order to function to their highest capabilities.

Epidemiology of Congenital Cataract

Congenital and infantile cataract is responsible for a fifth of the world’s blind children despite its treatable nature. It is thus an important cause of avoidable childhood visual disability. International variance in the frequency of the disorder reflect the global patterns of the overall health and survival of children as well as the socio-economic developmental status of and health infrastructure within the regions in question. Epidemiological research underpins the management of congenital cataract informing practice at both population level, e.g. screening and service planning, and child level, e.g. prognostication and clinical decision making. As the majority of cases are due to as yet undetermined causes, secondary prevention approaches (surgical and optical rehabilitation), and epidemiological investigation and assessment of these approaches, are key to reducing the burden of childhood cataract blindness.

Tests for detecting strabismus in children aged 1 to 6 years in the community

BACKGROUNDnStrabismus (misalignment of the eyes) is a risk factor for impaired visual development both of visual acuity and of stereopsis. Detection of strabismus in the community by non-expert examiners may be performed using a number of different index tests that include direct measures of misalignment (corneal or fundus reflex tests), or indirect measures such as stereopsis and visual acuity. The reference test to detect strabismus by trained professionals is the cover‒uncover test.nnnOBJECTIVESnTo assess and compare the accuracy of tests, alone or in combination, for detection of strabismus in children aged 1 to 6 years, in a community setting by non-expert screeners or primary care professionals to inform healthcare commissioners setting up childhood screening programmes.Secondary objectives were to investigate sources of heterogeneity of diagnostic accuracy.nnnSEARCH METHODSnWe searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 12) (which contains the Cochrane Eyes and Vision Trials Register) in the Cochrane Library, the Health Technology Assessment Database (HTAD) in the Cochrane Library (2016, Issue 4), MEDLINE Ovid (1946 to 5 January 2017), Embase Ovid (1947 to 5 January 2017), CINAHL (January 1937 to 5 January 2017), Web of Science Conference Proceedings Citation Index-Science (CPCI-S) (January 1990 to 5 January 2017), BIOSIS Previews (January 1969 to 5 January 2017), MEDION (to 18 August 2014), the Aggressive Research Intelligence Facility database (ARIF) (to 5 January 2017), the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 5 January 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 5 January 2017 and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 5 January 2017. We did not use any date or language restrictions in the electronic searches for trials. In addition, orthoptic journals and conference proceedings without electronic listings were searched.nnnSELECTION CRITERIAnAll prospective or retrospective population-based test accuracy studies of consecutive participants were included. Studies compared a single or combination of index tests with the reference test. Only those studies with sufficient data for analysis were included specifically to calculate sensitivity and specificity and determine diagnostic accuracy.Participants were aged 1 to 6 years. Studies reporting participants outside this range were included if subgroup data were available.Permitted settings included population-based vision screening programmes or opportunistic screening programmes, such as those performed in schools.nnnDATA COLLECTION AND ANALYSISnWe used standard methodological procedures expected by Cochrane. In brief, two review authors independently assessed titles and abstracts for eligibility and extracted the data, with a third senior author resolving any disagreement. We analysed data primarily for specificity and sensitivity.nnnMAIN RESULTSnOne study from a total of 1236 papers, abstracts and trials was eligible for inclusion with a total number of participants of 335 of which 271 completed both the screening test and the gold standard test. The screening test using an automated photoscreener had a sensitivity of 0.46 (95% confidence interval (CI) 0.19 to 0.75) and specificity of 0.97 (CI 0.94 to 0.99). The overall number affected by strabismus was low at 13 (4.8%).nnnAUTHORS CONCLUSIONSnThere is very limited data in the literature to ascertain the accuracy of tests for detecting strabismus in the community as performed by non-expert screeners. A large prospective study to compare methods would be required to determine which tests have the greatest accuracy.