Refractive error is the most common eye disorder worldwide, and 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 subjects of European ancestry, of which 8 were shared with Asians. Combined analysis revealed 8 additional loci. The new loci include genes with functions in neurotransmission (GRIA4), ion channels (KCNQ5), retinoic acid metabolism (RDH5), extracellular matrix remodeling (LAMA2, BMP2), and eye development (SIX6, 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 subjects with the highest genetic load. Our results, accumulated across independent multi-ethnic studies, considerably advance understanding of mechanisms involved in refractive error and myopia.

The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy and aligns with other existing health initiatives, such as obesity prevention, by promoting a healthier lifestyle for children and adolescents. Useful clinical measures to reduce or slow the progression of myopia include the daily application of low-dose atropine eye drops, in concentrations ranging between 0.01% and 0.05%, despite the side effects of a slightly reduced amplitude of accommodation, slight mydriasis, and risk of an allergic reaction; multifocal spectacle design; contact lenses that have power profiles that produce peripheral myopic defocus; and orthokeratology using corneal gas-permeable contact lenses that are designed to flatten the central cornea, leading to midperipheral steeping and peripheral myopic defocus, during overnight wear to eliminate daytime myopia. The risk-to-benefit ratio needs to be weighed up for the individual on the basis of their age, health, and lifestyle. The measures listed above are not mutually exclusive and are beginning to be examined in combination.

ABSTRACT.Purpose: To examine myopic progression and factors connected with myopic progression. Methods: Myopic schoolchildren, with no previous spectacles, 119 boys and 121 girls, were recruited during 1983-1984 to a randomized 3-year clinical trial of bifocal treatment of myopia with a subsequent 20-year follow-up. Participants' mean age at Baseline was 10.9, ranging from 8.7 to 12.8 years. An ophthalmological examination was carried out annually for 3 years and twice thereafter at ca. 10-year intervals. Additional refraction values were received from prescriptions issued by different ophthalmologists and opticians. Altogether, 1915 refraction values were available. Reading distance and accommodation were measured at each control visit. Data on parents' myopia, daily time spent on reading and close work, outdoor activities and watching television were gathered with a structured questionnaire. Results: Using bifocals (+1.75 add) or reading without glasses or accommodation stimulus during the 3-year period in childhood did not correlate with adulthood refraction. Short reading distance in childhood predicted higher adulthood myopia among females. The factors predicting faster myopic progression were parents' myopia and less time spent on sports and outdoor activities at childhood. Time spent on reading and close work in childhood was related to myopic progression during the first 3 years but did not predict adulthood myopia. Myopia throughout follow-up was higher among those who watched television <3 hr daily than those who spent more time watching television. Mean myopic progression 8 years after age 20-24 was À0.45 D AE 0.71 (SD), and in 45% of cases, progression was ≥0.5 D. Conclusions: In nearly half of the cases, myopia beginning at school continued to progress into adulthood. Higher adulthood myopia was mainly related to parents' myopia and less time spent on sports and outdoor activities in childhood.