Education and myopia: assessing the direction of causality by mendelian randomisation

@article{Mountjoy2018EducationAM,
  title={Education and myopia: assessing the direction of causality by mendelian randomisation},
  author={Edward Mountjoy and Neil Martin Davies and Denis Plotnikov and George Davey Smith and Santiago Rodr{\'i}guez and Cathy Williams and Jeremy A. Guggenheim and Denize Atan},
  journal={The BMJ},
  year={2018},
  volume={361}
}
Abstract Objectives To determine whether more years spent in education is a causal risk factor for myopia, or whether myopia is a causal risk factor for more years in education. Design Bidirectional, two sample mendelian randomisation study. Setting Publically available genetic data from two consortiums applied to a large, independent population cohort. Genetic variants used as proxies for myopia and years of education were derived from two large genome wide association studies: 23andMe and… 
Evaluation of Shared Genetic Susceptibility to High and Low Myopia and Hyperopia.
TLDR
The findings suggest that treatment interventions targeting common genetic risk variants associated with refractive error could be effective against both LM and HM.
Education and lung cancer: a Mendelian randomization study.
TLDR
Low education is a causal risk factor in the development of lung cancer, and genetic predisposition towards longer education was additionally associated with less smoking, lower body mass index and a favourable blood lipid profile.
Association between birth weight and refractive error in adulthood: a Mendelian randomization study. British Journal
TLDR
This study suggests lower birth weight within the normal range is causally associated with a more myopic refractive error, however, the impact of the causal effect was modest and covering approximately 95% of the population.
Association Between Polygenic Risk Score and Risk of Myopia
TLDR
A personalized medicine approach appears to be feasible for detecting very young children aged 0 to 6 years at risk of myopia; however, beyond the age of 6 years, cycloplegic autorefraction seems to perform better.
Risk Factors for Myopia: Putting Causal Pathways into a Social Context
TLDR
It is argued that there are two major environmental risk factors for school myopia, with a limited role for genetic variation and minimal interactions, and a method for comparing the impact of identified genetic risk factors with the cumulative effects of environmental exposures is proposed.
Temporal trends in frequency, type and severity of myopia and associations with key environmental risk factors in the UK: Findings from the UK Biobank Study
TLDR
The differential impact of educational experience/intensity on both childhood-onset and high myopia, amplified over time, suggests a cohort effect in gene-environment interaction with potential for increasing myopia frequency if increasing childhood educational intensity is unchecked.
Geographical Variation in Likely Myopia and Environmental Risk Factors: A Multilevel Cross Classified Analysis of A UK Cohort
TLDR
It is demonstrated how a multilevel modelling approach can provide a more nuanced understanding of the relationship between geography and myopia, and raise the possibility that some of the results reported may have been driven by confounding bias.
Hyperopia Is Not Causally Associated With a Major Deficit in Educational Attainment
TLDR
It is suggested that the causal relationship between refractive error and educational attainment was nonlinear but found no evidence that moderate hyperopia caused a major deficit in educational attainment.
Phenotypic and genotypic correlation between myopia and intelligence
TLDR
Novel findings indicate shared genetic factors contribute significantly to the covariance between myopia and intelligence, suggesting genetic pleiotropy.
The Genetics of Myopia
TLDR
Myopia is a complex trait, with many genetic variants of small effect influencing retinal signaling, eye growth and the normal process of emmetropization and while genetic risk score prediction models are improving, this knowledge must be expanded to have impact on clinical practice.
...
...

References

SHOWING 1-10 OF 82 REFERENCES
Phenotypic and genotypic correlation between myopia and intelligence
TLDR
Novel findings indicate shared genetic factors contribute significantly to the covariance between myopia and intelligence, suggesting genetic pleiotropy.
Association Between Myopia, Ultraviolet B Radiation Exposure, Serum Vitamin D Concentrations, and Genetic Polymorphisms in Vitamin D Metabolic Pathways in a Multicountry European Study
TLDR
Increased UVB exposure was associated with reduced myopia, particularly in adolescence and young adulthood, and no convincing evidence for a direct role of vitamin D in myopia risk was found.
What can mendelian randomisation tell us about modifiable behavioural and environmental exposures?
TLDR
Using genetic variants as a proxy for modifiable environmental factors that are associated with disease can circumvent some of the problems of observational studies, and the inferences that can be drawn from mendelian randomisation studies depend on the different ways in which genetic variants can proxy for environmentally modifiable exposures.
Genome-wide association study identifies 74 loci associated with educational attainment
TLDR
Because educational attainment is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric diseases.
EPIDEMIC OF PATHOLOGIC MYOPIA: What Can Laboratory Studies and Epidemiology Tell Us?
TLDR
Systematic review shows that there is an epidemic of myopia and high myopia in young adults in East and Southeast Asia, with similar but smaller trends in other parts of the world, suggesting an impending epidemic of pathologic myopia.
Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia
TLDR
The CREAM consortium conducted genome-wide meta-analyses, which identified 16 new loci for refractive error in individuals of European ancestry and 8 were shared with Asians, and identified 8 additional associated loci.
'Mendelian randomization': can genetic epidemiology contribute to understanding environmental determinants of disease?
TLDR
Mendelian randomization provides new opportunities to test causality and demonstrates how investment in the human genome project may contribute to understanding and preventing the adverse effects on human health of modifiable exposures.
Assumption-free estimation of the genetic contribution to refractive error across childhood
TLDR
This value sets an upper limit for predicting refractive error using existing SNP genotyping arrays, although higher-density genotypes in larger samples and inclusion of interaction effects is expected to raise this figure toward twin- and family-based heritability estimates.
...
...