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As one of the leading causes of visual impairment and blindness, myopia poses a significant public health burden in Asia. The primary determinant of myopia is an elongated ocular axial length (AL). Here we report a meta-analysis of three genome-wide association studies on AL conducted in 1,860 Chinese adults, 929 Chinese children, and 2,155 Malay adults. We identified a genetic locus on chromosome 1q41 harboring the zinc-finger 11B pseudogene ZC3H11B showing genome-wide significant association with AL variation (rs4373767, β = -0.16 mm per minor allele, P(meta) =2.69 × 10(-10)). The minor C allele of rs4373767 was also observed to significantly associate with decreased susceptibility to high myopia (per-allele odds ratio (OR) =0.75, 95% CI: 0.68-0.84, P(meta) =4.38 × 10(-7)) in 1,118 highly myopic cases and 5,433 controls. ZC3H11B and two neighboring genes SLC30A10 and LYPLAL1 were expressed in the human neural retina, retinal pigment epithelium, and sclera. In an experimental myopia mouse model, we observed significant alterations to gene and protein expression in the retina and sclera of the unilateral induced myopic eyes for the murine genes ZC3H11A, SLC30A10, and LYPLAL1. This supports the likely role of genetic variants at chromosome 1q41 in influencing AL variation and high myopia.

Corneal astigmatism refers to refractive abnormalities and irregularities in the curvature of the cornea, and this interferes with light being accurately focused at a single point in the eye. This ametropic condition is highly prevalent, influences visual acuity, and is a highly heritable trait. There is currently a paucity of research in the genetic etiology of corneal astigmatism. Here we report the results from five genome-wide association studies of corneal astigmatism across three Asian populations, with an initial discovery set of 4,254 Chinese and Malay individuals consisting of 2,249 cases and 2,005 controls. Replication was obtained from three surveys comprising of 2,139 Indians, an additional 929 Chinese children, and an independent 397 Chinese family trios. Variants in PDGFRA on chromosome 4q12 (lead SNP: rs7677751, allelic odds ratio = 1.26 (95% CI: 1.16-1.36), P(meta) = 7.87×10(-9)) were identified to be significantly associated with corneal astigmatism, exhibiting consistent effect sizes across all five cohorts. This highlights the potential role of variants in PDGFRA in the genetic etiology of corneal astigmatism across diverse Asian populations.

To evaluate parental history of myopia as a predictor of refractive error and eye size in Chinese pre-school children. A total of 514 pre-school children (aged 2.3–6.4 years) were examined. Parental history of myopia, amount of near work performed, refractive status and ocular biometry were recorded. There was no significant difference in spherical equivalent refraction (SER) among children with no myopic parents (mean + 0.94 ± 0.05 D), one myopic parent (mean + 0.77 ± 0.07 D) and two myopic parents (mean + 0.79 ± 0.12 D) (p = 0.102) after controlling for age and amount of near work. Further, children with more myopic parents did not have longer eyeballs (p = 0.335). In this study in Chinese pre-school children, parental history of myopia was not found to be associated with a myopic refractive error or increased eyeball length. Further studies with larger sample sizes would help to confirm these results. [ABSTRACT FROM AUTHOR]

Myopia is far beyond its inconvenience and represents a true, highly prevalent, sight-threatening ocular condition, especially in Asia. Without adequate interventions, the current epidemic of myopia is projected to affect 50% of the world population by 2050, becoming the leading cause of irreversible blindness. Although blurred vision, the predominant symptom of myopia, can be improved by contact lenses, glasses or refractive surgery, corrected myopia, particularly high myopia, still carries the risk of secondary blinding complications such as glaucoma, myopic maculopathy and retinal detachment, prompting the need for prevention. Epidemiological studies have reported an association between outdoor time and myopia prevention in children. The protective effect of time spent outdoors could be due to the unique characteristics (intensity, spectral distribution, temporal pattern, etc.) of sunlight that are lacking in artificial lighting. Concomitantly, studies in animal models have highlighted the efficacy of light and its components in delaying or even stopping the development of myopia and endeavoured to elucidate possible mechanisms involved in this process. In this narrative review, we (1) summarize the current knowledge concerning light modulation of ocular growth and refractive error development based on studies in human and animal models, (2) summarize potential neurobiological mechanisms involved in the effects of light on ocular growth and emmetropization and (3) highlight a potential pathway for the translational development of noninvasive light-therapy strategies for myopia prevention in children., Competing Interests: Conflict of interest statement: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s), 2021.)

Objective: Greater maternal adiposity is a potentially modifiable risk factor for elevated blood pressure during pregnancy; however, the association has been little studied in Asian populations, and no study has evaluated potential differences in the adiposity-blood pressure relation between ethnic groups or interaction with gestational diabetes., Methods: We performed a cross-sectional evaluation of a Singapore mother-offspring cohort comprising 799 pregnant Chinese, Malay and Indian women. Data on body weight, height, skinfold thickness and glycaemia (oral glucose tolerance test) were collected during the 2nd trimester; peripheral SBP and DBP were measured using an oscillometric device and central pressures by noninvasive radial applanation tonometry. The associations between adiposity measures BMI and sum of skinfold thickness and blood pressure outcomes were examined by linear regression with adjustment for potential confounders., Results: Higher maternal BMI was associated with elevated peripheral and central pressures: the increases in pressure (mmHg) for each kg/m(2) increase in BMI were 1.19 (95% confidence interval, 1.03-1.36) for peripheral SBP, 0.76 (0.63-0.89) for peripheral DBP, 1.02 (0.87-1.17) for central systolic pressure and 0.26 (0.16-0.37) for central pulse pressure. The associations were generally stronger in Chinese women (P-interaction = 0.03 for central pulse pressure) and individuals with gestational diabetes (P-interaction = 0.03 for DBP and P-interaction = 0.046 for central systolic pressure). Similar patterns of results were found when using skinfold thickness as the measure of adiposity., Conclusion: Maternal adiposity is associated with higher peripheral and central blood pressures during pregnancy. Stronger associations in Chinese women and individuals with gestational diabetes warrant further investigation.