May 1, 2020
By Dwight Akerman, OD, MBA, FAAO
Chief Medical Editor
Review of Myopia Management
The prevalence of pediatric myopia has risen rapidly over the past 30 years throughout the world. Although the causes of such a rise over a short time are probably due to environmental and cultural changes, refractive errors are highly heritable. Several studies have previously sought to identify genes controlling molecular mechanisms that lead to refractive error and myopia. However, the variance and heritability that can be attributed to known genetic factors are modest, and our knowledge of pathogenic mechanisms remains partial. Understanding the genetic contributors to myopia could help identify new avenues for treatment and prevention.
This study, which included more than half a million individuals of European ancestry, pinpointed more than 300 regions, or loci, across the genome that were strongly associated with refractive error and myopia risk. These loci, which had not previously been linked to this vision disorder, successfully predicted myopia in up to 75% of the participants tested. Also, researchers found that genes within these loci that contribute to myopia risk are also involved in growth, development, and pigmentation of the eye, and maintenance of circadian rhythm. Furthermore, this study helps to understand better the molecular mechanisms underlying myopia.
The results of this research highlight potential mechanisms that contribute to refractive error in the general population and the genetic factors that explain a considerable proportion of the heritability and phenotypic variability of refractive error. The researchers believe we are now heading towards having the ability to predict which children will become myopic based on their genetic markers. If we can develop treatments to prevent myopia, these genetic findings may be able to help identify those who are at the highest risk and need them most.
Meta-analysis of 542,934 subjects of European ancestry identifies new genes and mechanisms predisposing to refractive error and myopia
Pirro G. Hysi, Hélène Choquet, … Christopher J. Hammond
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.
Hysi, P. G., Choquet, H., Khawaja, A. P., Wojciechowski, R., Tedja, M. S., Yin, J., … & Cumberland, P. M. (2020). Meta-analysis of 542,934 subjects of European ancestry identifies new genes and mechanisms predisposing to refractive error and myopia. Nature Genetics, 1-7.