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Purpose: The association between sleep and myopia in children and adolescents has been reported, yet it remains controversial and inconclusive. This study aimed to investigate the influence of different sleep traits on the risk of myopia using meta-analytical and Mendelian randomization (MR) techniques., Methods: The literature search was performed in August 31, 2023 based on PubMed, Embase, Web of Science, and Cochrane library. The meta-analysis of observational studies reporting the relationship between sleep and myopia was conducted. MR analyses were carried out to assess the causal impact of genetic pre-disposition for sleep traits on myopia., Results: The results of the meta-analysis indicated a significant association between the risk of myopia and both short sleep duration [odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.08-1.42, P = 0.003] and long sleep duration (OR = 0.75, 95% CI = 0.66-0.86, P < 0.001). MR analyses revealed no significant causal associations of genetically determined sleep traits with myopia, including chronotype, sleep duration, short sleep duration and long sleep duration (all P > 0.05)., Conclusions: No evidence was found to support a causal relationship between sleep traits and myopia. While sleep may not independently predict the risk of myopia, the potential impact of sleep on the occurrence and development of myopia cannot be disregarded., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: This study examined the moderating role of outdoor time on the relationship between overweight and myopia., Methods: The data for this study was obtained from a prospective study in Shanghai, where non-myopic children wore wristwear and were followed up for 1 year. Eye examinations were performed at each visit. The modification effect was assessed on the additive scale using multivariable logistic regression, and relative excess risk due to interaction was used to calculate the modification effect., Results: A total of 4683 non-myopic children were included with 32.20% being overweight at baseline. Following a 1-year period, 17.42% of children had myopia. When compared to those who spent <90 minutes outdoors, children who spent >120 had a relative risk of myopia onset that was reduced to 0.61. As time spent outdoors decreased, more risks of myopia onset were identified among overweight children than among normal children, the modification effect on the additive scale was -0.007, with ~70% of this effect attributed to the modifying influence of outdoor time., Conclusions: Increasing outdoor time can reduce myopia more among overweight children than normal. Future interventions should focus on outdoor activities among overweight children to reduce myopia risks., (© The Author(s) 2024. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: To identify potential risk factors for myopia in children and adolescents and assess the credibility of each evidence, providing reference for the development of myopia prevention strategies., Methods: We searched PubMed, Web of Science and Embase databases from inception to April 2022 to find systematic reviews or meta-analyses investigating the relationship between potential risk factors and myopia, and conducted an umbrella review. We recalculated the pooled effect sizes and 95% CIs of each potential risk factor through random-effects model, and reported its 95% prediction interval and between-study heterogeneity. Small-study effect and excess of significance bias were assessed to reveal potential publication bias., Results: Twelve publications were included in this umbrella review, including eight meta-analyses and four qualitative systematic reviews. Twenty-two factors were identified, of which 16 were analysed quantitatively. Ten factors showed statistically significant association with myopia. Myopia in one or two parents and per additional hour of time spend outdoors per week were rated as highly suggestive evidence. Near work and gender were evaluated as suggestive evidence. The other five factors are weak evidence., Conclusions: We found several risk factors for myopia with different levels of evidence, of which parental myopia presented the strongest association with myopia in children and adolescents. Our findings contribute to a better understanding of the association between potential risk factors and myopia among children and adolescents and are important for informing parenting, education, clinical practice guidelines and public health policy., Prospero Trial Registration Number: CRD42022333053., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To assess the associations of corneal biomechanical properties as measured by the Corvis ST with refractive errors and ocular biometry in an unselected sample of young adults., Methods: A total of 1645 healthy university students underwent corneal biomechanical parameters measurement by the Corvis ST. The refractive status of the participants was measured using an autorefractor without cycloplegia. Ocular biometric parameters were measured using the IOL Master., Results: After adjusting for the effect of age, sex, biomechanical-corrected intraocular pressure and central corneal thickness, axial length was significantly associated with A1 velocity (A1v, β = -10.47), A2 velocity (A2v, β = 4.66), A2 deflection amplitude (A2DeflA, β = -6.02), HC deflection amplitude (HC-DeflA, β = 5.95), HC peak distance (HC-PD, β = 2.57), deformation amplitude ratio max (DA Rmax, β = -0.36), Ambrósio's relational thickness to the horizontal profile (ARTh, β = 0.002). For axial length / corneal radius ratio, only A1v (β = -2.01), A1 deflection amplitude (A1DeflA, β = 2.30), HC-DeflA (β = 1.49), HC-PD (β = -0.21), DA Rmax (β = 0.07), stress-strain index (SSI, β = -0.29), ARTh (β < 0.001) were significant associates. A1v (β = 23.18), HC-DeflA (β = -15.36), HC-PD (β = 1.27), DA Rmax (β = -0.66), SSI (β = 3.53), ARTh (β = -0.02) were significantly associated with spherical equivalent., Conclusion: Myopic eyes were more likely to have more deformable corneas and corneas in high myopia were easier to deform and were even softer compared with those in the mild/moderate myopia., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Eye movement has been frequently studied in clinical conditions, but the association with myopia has been less explored, especially in population-based samples. The purpose of this study was to assess the associations of eye movement measured by the Corvis ST with refractive status in healthy university students., Methods: A total of 1640 healthy students were included in the study (19.0 ± 0.9 years). Eye movement parameters (whole eye movement [WEM]; whole eye movement time [WEMT]) were measured by the Corvis ST. Spherical equivalent (SE) was measured using an autorefractor without cycloplegia. IOL Master was used to assess axial length (AL)., Results: AL was negatively correlated with WEM and WEMT (rWEM = -0.28, rWEMT = -0.08), and SE was positively correlated with WEM and WEMT (rWEM = 0.21, rWEMT = 0.14). For the risk of high myopia, breakpoint analysis and restricted cubic spline model showed that the knots of the significant steep downward trend of WEM and WEMT were 0.27 mm and 20.4 ms, respectively. The piecewise linear regression model revealed a significant correlation between AL, SE, and WEM when the value of WEM was below 0.27 mm. Additionally, when WEMT exceeded 20.4 ms, a significant decrease in AL and an increase in SE were observed with increasing WEMT., Conclusions: A larger distance and longer duration of eye movement were correlated with a lower degree of myopia and shorter AL, and there was a threshold effect., Translational Relevance: The findings might aid in understanding the pathogenesis of myopia and provide a theoretical foundation for clinical diagnosis and prediction.

Background: Myopia is prevalent in children and adolescents. Understanding the effect of multiple behaviors and their latent patterns on ocular biometric parameters may help clinicians and public health practitioners understand the behavioral risk pattern of myopia from a person-centered perspective. The purpose of this study was to identify the patterns of four major behavioral risk factors associated with myopia, including time spent outdoors, digital screen time, sleep duration, and performance of Chinese eye exercises. The study also examined the relationships between these behavioral patterns and myopia as well as ocular biometric parameters in a sample of Chinese college students., Methods: This study included 2014 students from the Dali University Students Eye Health Study. The average age of the subjects was 19.0 ± 0.9 years old, ranging from 15.7 to 25.1 years old. Each participant's refractive status was measured using an autorefractor without cycloplegia and ocular biometric parameters were measured using an IOL Master. Behavioral risk factors were collected using a pre-designed self-administered questionnaire. Latent class analysis (LCA) was performed to identify cluster patterns of various behaviors., Results: The prevalence of myopia was 91.8% in this population. The 2-class model was selected for the LCA based on goodness-of-fit evaluation metrics. Among the overall study sample, 41.1% and 58.9% were assigned into the high-risk and low-risk class, respectively. The risk of myopia [odds ratio (OR) = 2.12, 95% confidence interval (CI) = 1.52-3.14], high myopia (OR = 1.43, 95% CI = 1.14-1.78) and axial length/corneal radius (AL/CR) ratio of more than 3.0 (OR = 1.82, 95% CI = 1.22-2.72) were significantly higher in the high-risk compared with low-risk class., Conclusions: Chinese university students showed differential risks of myopia and could be subdivided into high- and low-risk clusters based on four behavioral variables., (© 2023. The Author(s).)

Background: Myopia is one of the major eye disorders and the global burden is increasing rapidly. Our purpose is to systematically summarize potential metabolic biomarkers and pathways in myopia to facilitate the understanding of disease mechanisms as well as the discovery of novel therapeutic measures., Methods: Myopia-related metabolomics studies were searched in electronic databases of PubMed and Web of Science until June 2021. Information regarding clinical and demographic characteristics of included studies and metabolomics findings were extracted. Myopia-related metabolic pathways were analysed for differential metabolic profiles, and the quality of included studies was assessed based on the QUADOMICS tool. Pathway analyses of differential metabolites were performed using bioinformatics tools and online software such as the Metaboanalyst 5.0., Results: The myopia-related metabolomics studies included in this study consisted of seven human and two animal studies. The results of the study quality assessment showed that studies were all phase I studies and all met the evaluation criteria of 70% or more. The myopia-control serum study identified 23 differential metabolites with the Sphingolipid metabolism pathway beings enriched. The high myopia-cataract aqueous humour study identified 40 differential metabolites with the Arginine biosynthesis pathway being enriched. The high myopia-control serum study identified 43 differential metabolites and 4 pathways were significantly associated with metabolites including Citrate cycle; Alanine, aspartate and glutamate metabolism; Glyoxylate and dicarboxylate metabolism; Biosynthesis of unsaturated fatty acids (all P value < 0.05)., Conclusions: This study summarizes potential metabolic biomarkers and pathways in myopia, providing new clues to elucidate disease mechanisms., (© 2022. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

Metabolomics analyzes the entire range of small molecule metabolites in biological systems to reveal the response signals that are transmitted from "genetics and environment", which could help us understand complex phenotypes of diseases. Metabolomics has been successfully applied to the study of eye diseases including age-related macular degeneration, glaucoma, and diabetic retinopathy. In this review, we summarize the findings of myopic metabolomics and discuss them from a design and analysis perspective. Finally, we provide new ideas for the future development of myopia metabolomics research based on the broader ocular metabolomics study., Competing Interests: Declaration of competing interest The authors have nothing to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Association between gene-environment interaction and myopia/spherical equivalent has not been systematically reported. This paper reviewed nine studies concerning gene-environment interaction in myopia., Methods: We obtained relevant studies concerning gene-environment interaction in myopia by systematically searching the MEDLINE(PubMed), Cochrane, Web of Science, CNKI, Wanfang databases before 31 March 2020. Data were analyzed by STATA version 16.0 software, and figures were drawn by ArcGIS V.10.0 software., Results: Nine studies were included in this review concerning gene-environment interaction. Gene and education interaction in adult cohorts suggested a more significant genetic effect in higher education levels than lower education levels, using both candidate genes and PRS approaches. Several interacted genetic variants, including ZMAT4(rs2137277), GJD2(rs524952), TJP2 (rs11145488) from adult study and ZMAT4(rs7829127) from child study are pinpointed out, but the replication attempts were limited. Besides, the genetic effect was associated with a significant shift at a higher educational level (Pooled β = -0.15,95%CI = -0.19-0.11) towards myopia than that at a lower education level (Pooled β = -0.10,95%CI = -0.11-0.09)., Conclusion: This study summarizes the relationship between gene-environment interaction and myopia, and interaction effect of the gene or genetic risk score with the environment could be found in these studies. The effect of gene-environment (higher education) interaction substantially impacts myopia in adult studies. Evidence that environmental factors (Increased near-work time/decreased outdoor activities) increase the genetic risk is still limited, and specific SNPs contributing to gene-environment effect are not determined yet.

Purpose: To examine the association between near work, screen time including TV and outdoor time with myopia in children from the Sunflower Myopia Asian Eye Epidemiology Consortium (AEEC)., Methods: We analysed AEEC cross-sectional data (12 241 children) on risk factors (near work, screen time including TV and outdoor time) and myopia of six population-based studies (China, Hong Kong and Singapore). Cycloplegic refraction and axial length (AL) measurements were included. Risk factors were determined using questionnaires. Data were pooled from each study, and multivariable regression analysis was performed to evaluate the associations between risks factors and myopia, spherical equivalent (SE) and AL., Results: Among the included children, 52.1% were boys, 98.1% were Chinese and 69.7% lived in urban areas. Mean±standard deviation (SD) for age was 8.8 ± 2.9 years, for SE was -0.14 ± 1.8 D and for AL was 23.3 ± 1.1 mm. Myopia prevalence was 30.6%. In multivariate analysis, more reading and writing (OR = 1.17; 95% CI, 1.11-1.24), more total near work (OR = 1.05; 95% CI, 1.02-1.09) and less outdoor time (OR = 0.82, 95% CI, 0.75-0.88) were associated with myopia (p's < 0.05). These factors were similarly associated with SE and AL (p's < 0.05), except for total near work and AL (p = 0.15). Screen time including TV was not significantly associated with myopia (p = 0.49), SE (p = 0.49) or AL (p = 0.83)., Conclusion: In this study, increased reading and writing and decreased outdoor time were associated with myopia. Screen time may be a surrogate factor of near work or outdoor time, but further research is needed to assess its role as an independent risk factor for myopia., (© 2021 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Backgrounds: Many literature reviews summarized relationships between screen time and child health, but they only included a few studies conducted in Chinese children and adolescents. The potential influence of screen time may vary by social context. The current systematic review and meta-analysis aimed to evaluate relationships between screen time and health issues among Chinese school-aged children and adolescents., Methods: Peer-reviewed articles written in Chinese and English were retrieved from CNKI, Wanfang, PubMed, Embase, and Web of Science from inception to June 2020. The Downs & Black checklist was applied to assess study quality. Meta analyses used random effect models and mixed effects model to calculate pooled adjusted odds ratios and 95% confidence intervals. Heterogeneity, sensitivity, and publication bias were assessed using Q and I 2 statistics, "one-study removed" analysis, the funnel plot, trim and fill analysis, and classical fail-safe N, respectively., Results: In total, we identified 252 articles reporting 268 studies with unique samples. These studies investigated relationships between screen time and health issues of adiposity, myopia, psycho-behavioral problems, poor academic performance, cardiometabolic disease risks, sleep disorder, poor physical fitness, musculoskeletal injury, sub-health, and miscellaneous issues of height and pubertal growth, injury, sick leave, and respiratory symptoms. Proportions of studies reporting positive relationships with screen time were lowest in adiposity (50.6%) and higher in myopia (59.2%) and psycho-behavioral problems (81.8%). Other health issues were examined in 10 or less studies, all of which had more than half showing positive relationships. The pooled odds ratio from 19 studies comparing health risks with the screen time cutoff of 2 hours per day was 1.40 (95% CI: 1.31 to 1.50, I 2  = 85.9%). The pooled effect size was 1.29 (95% CI: 1.20 to 1.39) after trimming 7 studies for publication bias adjustments., Conclusions: Findings exclusively generated from Chinese school-aged children and adolescents resonate those mainly from western countries. Evidence suggests that higher levels of screen time are related with greater risks of various health issues, although the relationships appear to be weak and intertwined with other confounding factors. Future studies need to investigate health-specific dose effects and mechanisms of screen time., (© 2022. The Author(s).)

Purpose: High myopia is associated with blinding ocular morbidities. Identifying novel biomarkers may provide clues on pathogenic pathways that are currently unknown. We aimed to identify serum metabolic biomarkers and investigate the metabolic alterations in relation to high myopia., Methods: Forty adults with high myopia and 40 with low myopia aged 60 years or older from the Weitang Geriatric Diseases study were included in the case-control study. Refractive error was determined by autorefraction followed by subjective refraction. We performed the metabolomic analysis of serum samples from patients with high myopia and age- and sex- matched controls with low myopia, using a nontargeted gas chromatography coupled to time-of-flight mass spectrometer. The area under the receiver operating characteristic curve (AUC) was computed to assess the discrimination capacities of each metabolite marker. Databases including KEGG and MetaboAnalyst were utilized to search for the potential pathways of metabolites., Results: Serum metabolomic profiles could well distinguish high myopia from low myopia. Twenty metabolic biomarkers were identified as potential serum biomarkers for high myopia, yielding AUC values of 0.59-0.71. Metabolic pathways in relation to high myopia, mainly characterized by increased energy metabolism, increased oxidative stress, abnormal amino acid metabolism, and altered biotin metabolism, provide a foundation to support myopia progression., Conclusions: This study identified valuable metabolic biomarkers and pathways that may facilitate an improved understanding of the disease pathogenesis. The finding holds translational value in the development of new therapeutic measures for high myopia-related complications.

Purpose : Parental rural-to-urban migration has a wide range of health effects on children's but its impact on children's refractive status remains unclear. We aim to examine whether parental rural-to-urban migration could influence the refractive status of their children in rural areas of China. Methods : Among the 2346 grade 7 students in the Mojiang Myopia Progression Study, information regarding parental migration was collected by questionnaires and was successfully obtained in 2105 participants. Refractive error was measured in diopters (D) with cycloplegia using an autorefractor and axial length (AL) was measured using an IOL Master. One-to-one nearest-neighbor matching techniques with a 0.01 caliper level were used to estimate the propensity score matching (PSM) models. Results : Among all the participants, 472 pairs (1 student with vs. 1 student without migrant parents) were successfully matched based on propensity scores. Students with migrant parents had a lower proportion of myopia (29.2% vs. 40.7%; P < .001) and more hyperopic refractions (-0.25D vs. -0.31D; P = .04) compared with those without. They also had shorter ALs (23.4 mm vs. 23.6 mm) but the difference was not significance ( P = .18). In addition, students with migrant parents spent less time reading after school per day (0.87 vs. 1.01 hours; P = .01). Conclusions : Myopia is less prevalent among children with migrant parents compared with those without. This study indicated that living without parents might be a protect factor for myopia in Chinese school student via giving them less pressure on study.

Background: We aimed to assess the relationship between breastfeeding and myopia in a school-based study in rural China. In addition, we performed a systematic review and meta-analysis to confirm the association from available observational studies. Materials and Methods: The school-based study of 2,346 grade 7 students (mean age: 13.8 years) was conducted in southwestern part of China. Myopia was defined as spherical equivalent of less than -0.50 diopter and information regarding breastfeeding was ascertained through a questionnaire. We also performed the literature search in three databases (PubMed, EMBASE, and Cochrane Central Register of Controlled Trials) and reference lists of retrieved studies. Effect estimates were pooled using random-effects models. Results: In our school-based study, the association between breastfeeding and myopia was marginally nonsignificant after adjusting for potential confounders, including gender, body mass index, parental myopia, time for reading and writing after school, and time outdoors (odds ratio = 0.75, 95% confidence interval: 0.55-1.04, p  = 0.09). In the meta-analysis of eight studies, no significant association was observed. Conclusion: Current evidence did not support that breastfeeding could reduce the risk of myopia in children and adolescents.

Purpose: Observational studies have suggested a possible relationship between disordered sleep and myopia, but the association may be subject to selection biases. We aimed to minimize selection biases and assess the association by applying a propensity score matching (PSM) approach., Methods: The study was designed as a school-based cross-sectional study on a Chinese cohort aged 13-14 years in rural areas of China. The Chinese version of the Children's Sleep Habits Questionnaire was used for the measurement of sleep quality and a score of 41 or more was used to define the presence of disordered sleep. Each participant's refractive status was measured after cycloplegia using an autorefractor and myopia was defined as spherical equivalent <-0.50 D. The propensity scores for disordered sleep were formulated using nine potential confounders. We matched the propensity scores for subjects with and without disordered sleep within a caliper of 0.01 of logit function of propensity scores., Results: In this study, 474 pairs (1 subject with vs. 1 subject without disordered sleep) were successfully matched based on propensity scores. The odds ratio (OR) of myopia for disordered sleep before PSM reached conventional levels of statistical significance (OR: 1.43 95% confidence interval [CI] 1.05, 2.58, p = 0.01). After matching, the magnitude of association was reduced and the OR of myopia was not significant (OR: 1.54 95% CI 0.90, 2.57, p = 0.46)., Conclusions: At current stage, there are insufficient evidence indicating that disordered sleep could affect the development of myopia in adolescents.

Background: To determine the one-year incidence and progression rates of myopia and its association with baseline ocular biometric parameters in school-based samples of children and adolescents in China., Methods: Two thousand four hundred thirty two grade 1 and 2346 grade 7 students living in the southwest part of China participated in the baseline survey. After 1 year, 2310 (95.0%) grade 1 and 2191 (93.4%) grade 7 students attended the follow-up examination. Refractive error was measured after cycloplegia using the same autorefractor and by the same optometrists in the baseline and follow-up examination. Myopia was defined as spherical equivalent of less than - 0.50 diopter., Results: The overall one-year incidence of myopia was 33.6% (95% confidence interval [CI]: 31.7-35.5) among grade 1 students and 54.0% (95% CI: 51.5-56.5) for grade 7 students. The one-year myopia progression rate was - 0.97 D (95% CI: -1.22 to - 0.71) in grade 1 students and - 1.02 D (95% CI: -1.07 to - 0.96) in grade 7 students. Per mm increase in baseline axial lengths increased the risk of myopia onset by 28% among grade 1 students and 22% among grade 7 students after 1 year. The incidence rates of myopia were found to be higher in grade 7 students with thinner premyopic lenses., Conclusions: The incidence and progression rates of myopia were very high in Chinese children and adolescents in recent years. Premyopic eyes were characterized with longer axial lengths and thinner lenses. These data had considerable implications for formulating myopia prevention strategies in China.

Background: We aim to assess the prevalence of myopia in Chinese school children with low educational pressure and explore which factors could explain the differences in prevalence between generations., Methods: A school-based epidemiologic study including 2432 grade 1 and 2346 grade 7 students was conducted from 2016 in rural areas of China. Each participant's refractive status was measured before and after cycloplegia using an autorefractor and axial length (AL) was measured using an IOL Master. The questionnaires were completed by the parents or legal guardians of the children to collect detailed information regarding risk factors. Myopia was defined as spherical equivalent less than - 0.50D., Results: Grade 7 students had a higher prevalence of myopia (29.4% vs. 2.4%; P < 0.001) and high myopia (0.4% vs. 0.1%; P < 0.001) compared with grade 1 students. Grade 7 students also had longer ALs (23.50 mm vs. 23.37 mm; p = 0.004) after adjusting for the effect of gender, height and other myopia-related risk factors. Adjustment for time spent on reading and writing after school per day led to a reduction in the excess prevalence of myopia in grade 7 students by 15.1%. In addition, adjustment for time outdoors reduced the excess prevalence of myopia in grade 7 students by 33.4%., Conclusions: We reported a relatively lower prevalence of myopia in school students in rural China, suggesting that Chinese may not have a genetic predisposition to myopia and environmental factors may play a major role in the development of school myopia in Chinese children.

Purpose: We aim to determine the association of the types of lamp for homework including incandescent lamp, fluorescent lamp, and light-emitting diode (LED) lamp with the prevalence of myopia in Chinese children., Methods: 2346 grade 7 students from ten middle schools (93.5% response rate) aged 13 to 14 years in Mojiang, a small county located in Southwestern China, participated in the study. Refractive error was measured with cycloplegia using an autorefractor by optometrists or trained technicians. An IOL Master was used to measure ocular biometric parameters including axial length (AL). Information regarding the types of lamp for homework af``ter schools was collected by questionnaires., Results: Of all the study participants, 693 (29.5%) were affected by myopia, with the prevalence estimates being higher in girls (36.8%; 95% confidence interval [CI]: 34.0, 39.6) than in boys (22.8%; 95% CI: 20.4, 25.1) (P < 0.001). After adjusting for potential confounders such as gender, height, parental history of myopia, time on computer use, time on watching TV, time outdoors, and time on reading and writing, participants using LED lamps for homework had a more myopic refractive error and a longer AL compared with those using incandescent or fluorescent lamps. There were no significant differences in myopia prevalence between children using incandescent and fluorescent lamps for homework. The population attributable risk percentage for myopia associated with using LED lamps for homework after schools was 11.2%., Conclusions: Using LED lamps for homework after schools might contribute to the development of myopia among school-aged children.

Purpose: Understanding the association of iris colour and myopia may provide further insights into the role of the wavelength of lights in the pathophysiology of myopia. We aim to assess the association of iris colour and myopia in a school-based sample of Chinese students., Methods: Two thousand three hundred and forty-six Year 7 students from 10 middle schools (93.5% response rate) aged 13-14 years in Mojiang, a small county located in Southwestern China, participated in the study. We obtained standardised slit lamp photographs and developed a grading system assessing iris colour (higher grade denoting a darker iris). Refractive error was measured after cycloplegia using an autorefractor by optometrists or trained technicians. An IOLMaster (www.zeiss.com) was used to measure ocular biometric parameters including axial length (AL)., Results: Of all the study participants, 693 (29.5%) were affected by myopia with the prevalence estimates being higher in girls (36.8%; 95% confidence interval [CI]: 34.0, 39.6) than in boys (22.8%; 95% CI: 20.4, 25.1) (p < 0.001). After adjusting for gender, height, parental history of myopia, time spent on computer, time spent watching TV, time spent outdoors, and time spent reading and writing, participants with a darker iris colour tended to have a higher prevalence of myopia, a more myopic refraction and a longer AL. Dose-response relationships were observed in all regression models (p for trend <0.05)., Conclusions: Darker iris colour was associated with more myopic refractive errors and longer ALs among Chinese school-aged children and this association was independent of other known myopia-related risk factors., (© 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.)

Purpose: Few population-based data support the hypothesis that refractive errors are associated with depressive symptoms. We aim to assess the impact of myopia on the risk of having depressive symptoms in a community-based cohort of elderly Chinese., Methods: A community-based cross-sectional study of 4611 Chinese adults aged 60 years or older was conducted. Depressive symptoms were measured using the 9-item Patient Health Questionnaire (PHQ-9) depression scale in 4597 adults. Refraction was determined by auto-refraction followed by subjective refraction. Myopia was defined as spherical equivalent (SE) < -0.50 diopters (D) and high myopia as SE < -6.00 D., Results: After adjusting for age, gender, education, lifestyle-related exposures, presenting visual acuity and age-related cataract, myopic adults were more likely to have any depressive symptoms compared with non-myopic ones (odds ratio = 1.39; 95% confidence interval 1.04, 1.92). There were no significant differences in the risk of having any depressive symptoms between those with and without high myopia. Myopia or high myopia was not associated with having moderate depressive symptoms. The impact of myopia on depressive symptoms was stronger in adults with no formal education compared with those with formal education., Conclusions: Myopia was related with the presence of depressive symptoms among older adults.

Background: Myopia is a major public health concern throughout the world and the prevalence has been increasing rapidly in recent years, especially in urban Asia. The "vitamin D hypothesis" has been raised recently because vitamin D may be a link between less time outdoors and increased risk of myopia., Methods: We reviewed all studies published in English which examined the association of time outdoors and blood vitamin D status with myopia., Results: The protective effect of time spent outdoors on the risk of myopia onset has been well-established with numerous observational studies and three trials published. Five studies reporting the association between the blood vitamin D status and the risk of myopia and two studies examining the variations in the vitamin D receptor as potential risk factors for myopia development were identified. Most of the current evidence was cross-sectional in nature and had not properly controlled important confounders in its analyses. The evidence supporting that vitamin D played a role in myopia development is weak and the mechanisms are unclear., Conclusions: At the current stage, it is still unclear whether blood vitamin D status regulates the onset or progression of myopia. Blood vitamin D status may only serve as a biomarker of outdoor exposure, which is the real protective factor for myopia.

Purpose: To determine the difference between cycloplegic and non-cycloplegic refractive error and its associated factors in Chinese children and adolescents with a high prevalence of myopia., Methods: A school-based study including 1565 students aged 6 to 21 years was conducted in 2013 in Ejina, Inner Mongolia, China. Comprehensive eye examinations were performed. Pre-and postcycloplegic refractive error were measured using an auto-refractor. For cycloplegic refraction, one drop of topical 1.0% cyclopentolate was administered to each eye twice with a 5-minute interval and a third drop was administered 15 minutes after the second drop if the pupil size was less than 6 mm or if the pupillary light reflex was still present., Results: Two drops of cyclopentolate were found to be sufficient in 59% of the study participants while the other 41% need an additional drop. The prevalence of myopia was 89.5% in participants aged over 12 years and 68.6% in those aged 12 years or younger (P<0.001). When myopia was defined as spherical equivalent (SE) of less than -0.5 diopter (D), the prevalence estimates were 76.7% (95% confidence interval [CI] 74.6-78.8) and 54.1% (95%CI 51.6-56.6) before and after cycloplegic refraction, respectively. When hyperopia was defined as SE of more than 0.5D, the prevalence was only 2.8% (95%CI 1.9-3.6) before cycloplegic refraction while it was 15.5% (95%CI 13.7-17.3) after cycloplegic refraction. Increased difference between cycloplegic and non-cycloplegic refractive error was associated with decreased intraocular pressures (P = 0.01)., Conclusions: Lack of cycloplegia in refractive error measurement was associated with significant misclassifications in both myopia and hyperopia among Chinese children and adolescents. Decreased intraocular pressure was related to a greater difference between cycloplegic and non-cycloplegic refractive error., Competing Interests: The authors have declared that no competing interests exist.

Purpose: We described the prevalence and associated factors of myopia and high myopia in school children of different ethnicities in a rural community in Yunnan province, China., Methods: A total of 7681 (93.4%) primary and secondary school students aged 5-16 years in Mangshi participated in this study. Cycloplegic refraction was performed using an auto-refractor. Information regarding demographic factors, socioeconomic status and lifestyle-related exposures were collected using a questionnaire. Multivariate logistic regression models were fitted to estimate the risk factors for myopia and high myopia., Results: The overall prevalence of myopia and high myopia was 39.1% (95% confidence interval [CI]: 38.0, 40.2) and 0.6% (95% CI: 0.4, 0.8) in this study. Myopia prevalence increased significantly with increasing age (p for trend <0.001). Girls were more likely to have myopia compared with boys (p < 0.001). In multivariate analysis, the presence of myopia was associated with increasing height (odds ratio [OR] = 1.02; 95% CI: 1.01, 1.03), computer use (OR = 1.17; 95% CI: 1.03, 1.32), having myopic father (OR = 1.56; 95% CI: 1.24, 1.94), having myopic mother (OR = 1.33; 95% CI: 1.08, 1.63), and increasing time on reading (OR = 1.18; 95% CI: 1.09, 1.28) after adjusting for age, sex and ethnicity., Conclusions: Nowadays myopia but not high myopia is prevalent among school children in rural China. Significant ethnic differences in myopia prevalence were not observed. A significant 'cohort effect' of myopia previously observed in urban cities had occurred in rural communities in China., (© 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.)

Purpose: The association between myopia and cognitive dysfunction among elderly adults was assessed by applying a Propensity Score Matching (PSM) approach. This is a statistical method which allows investigators to estimate causal treatment effects using observational or nonrandomised data., Methods: The study was designed as a community-based cross-sectional study based on a Chinese cohort aged 60 years or older in China. Objective refraction was measured using an autorefractor and subjective refraction was used to refine vision, using the results of the objective refraction as the starting point. Myopia was defined as a spherical equivalent value of less than -0.50 dioptre (D) in the right eye. The Abbreviated Mental Test (AMT) was used for cognitive assessment. The propensity scores for myopia were formulated using 13 potential confounders. We matched the propensity scores for subjects with and without myopia within a caliper of 0.01 of logit function of propensity scores., Results: About 4123 elderly adults who successfully completed the AMT were included in this analysis. The odds ratio (OR) of cognitive dysfunction for myopia before matching was 1.98 (95% confidence interval [CI] 1.61, 2.44; p < 0.001). There were significant covariate imbalances between comparison groups and after propensity score matching, covariate imbalance was significantly reduced. After propensity score matching, the OR of cognitive dysfunction was marginally significant and the magnitude of association was reduced (OR: 1.31 95% CI 1.00, 1.71; p = 0.05). Traditional multivariate logistic regression modelling found an OR of 1.52 (95% CI 1.23, 2.06; p < 0.001) after adjusting for the 13 potential confounders., Conclusions: Myopia was associated with a higher prevalence of cognitive dysfunction among elderly Chinese aged 60 years or older in China. The PSM approach may be a useful method to address selection bias in observational studies when randomised trials cannot ethically be conducted., (© 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.)

Purpose: To determine the prevalence of myopia and ocular biometry in population-based samples of ethnic Yi and Han people living in an inland rural community in China., Methods: A random cluster sampling strategy was used to select ethnic Han and Yi adults aged 50 years or older living in Yunnan. Refractive error was determined by subjective refraction and ocular biometric parameters, including axial length (AL), anterior chamber depth (ACD), vitreous chamber depth (VCD), and lens thickness (LT), which were measured using an Echoscan., Results: Adults of Yi ethnicity had lower prevalence of myopia (10.3% vs. 8.1%; P = 0.02) and high myopia (2.3% vs. 1.6%; P = 0.10) than their counterparts of Han ethnicity. The prevalence of myopia increased with age (P for trend < 0.05), whereas the mean AL did not differ significantly among age groups in both ethnic groups (both P for trend > 0.05). In multivariate analysis, time spent outdoors was associated with myopia (P = 0.003) and AL (P < 0.001) but not high myopia (P = 0.33). No interaction effect was detected between ethnicity and other risk factors on myopia (all P > 0.05). Adjustment for lens nuclear opacity score reduced the excess prevalence of myopia in Han ethnicity by 37.5%., Conclusions: There was little evidence showing that ethnic disparities existed in the prevalence and risk factors between the major and minor ethnic groups living in the same communities in rural China. The "cohort effect" on myopia observed in many other populations was not seen in this study.

Purpose: To estimate the age-specific prevalence of myopia in Asia., Methods: We searched PubMed, Embase, and Web of Science from their inception through September 2013 for population-based surveys reporting the prevalence of myopia in adults or children in Asia. We pooled the prevalence estimates for myopia by age groups and by year of birth using a random-effects model., Results: We identified 50 eligible population-based studies including 215,672 subjects aged 0 to 96 years reporting the prevalence of myopia from 16 Asian countries or regions. Myopia was found to be most prevalent (96.5%; 95% confidence interval, 96.3 to 96.8) in Koreans aged 19 years. There was no significant linear age group effect on the prevalence of myopia in the whole Asian population but there was a U-shaped relationship between both age and year of birth and the prevalence of myopia. The prevalence of myopia was also higher in those older than 70 years (36.3%; 95% confidence interval, 27.6 to 45.0) compared with other age groups, which revealed nuclear cataract-myopia shifts in refraction., Conclusions: There is a large variation in the age-specific prevalence of myopia in Asia. A U-shaped relationship between age and the prevalence of myopia was found in the whole Asian population. The analysis is essential to guide future eye health care, intervention, and clinical management in Asia.

Importance: Understanding the burden and trends of reduced visual acuity (VA), a proxy measure for myopia, is essential to guide future health care and clinical management in China., Objectives: To describe the secular trends from 1985 to 2010, correlate the prevalence of reduced VA among children and adolescents with population density, and project the burden of reduced VA in China in 2020 and 2030., Design: The National Survey on the Constitution and Health of Chinese Students conducted from 1985 to 2010, including 6 repeated surveys with a 3-stage clustering sampling strategy., Setting: Mainland China., Participants: Primary and secondary school students 7 to 18 years of age were randomly selected from 30 of 31 mainland provinces, excluding Tibet., Main Outcomes and Measures: Unaided distance VA was measured using a retroilluminated logMAR chart with tumbling-E optotypes. World Population Prospects data (the 2012 revision from the Population Division of the Department of Economic and Social Affairs of the United Nations) were used to project the number of people affected by reduced VA in 2020 and 2030., Results: This analysis included 725 423, 142 655, 206 601, 219 663, 234 377, and 215 308 students in 1985, 1991, 1995, 2000, 2005, and 2010, respectively. The overall prevalence of reduced VA was 28.6% (95% CI, 28.4%-28.7%) in 1985, 38.6% (95% CI, 38.3%-38.8%) in 1991, 41.0% (95% CI, 40.8%-41.2%) in 1995, 38.5% (95% CI, 38.3%-38.7%) in 2000, 49.5% (95% CI, 49.3%-49.7%) in 2005, and 56.8% (95% CI, 56.6%-57.0%) in 2010. Girls were more susceptible than boys to having reduced VA (odds ratio, 1.38 [95% CI, 1.35-1.40]), and reduced VA was more prevalent in urban areas than in rural areas (odds ratio, 1.84 [95% CI, 1.81-1.87]). Reduced VA was not significantly associated with population density (P = .11). The projected numbers of cases with reduced VA are about 152.4 million (95% CI, 151.9-152.9 million) in 2020, increasing to 180.4 million (95% CI, 179.8-181.2 million) in 2030 among students who are 7 to 18 years of age in mainland China., Conclusions and Relevance: There was an increasing trend of reduced VA in both urban and rural areas from 1985 to 2010 in China. Although reduced unaided distance VA is not equal to visual impairment, these summary data are helpful in designing strategies for eye care and health services in China, which may also have public health implications for other developing countries whose economies are growing rapidly.

Purpose: To evaluate an incentive-based intervention to increase time spent outdoors among children in a 9-month cluster randomised controlled trial., Methods: Two hundred and eighty-five children aged 6-12 years of age were randomised to the intervention (n = 147) or control arm (n = 138) in the Family incentive trial (FIT). The FIT intervention comprised of targeted education on myopia and good eye care habits, structured weekend outdoor activities and incentives for children to increase their daily steps via pedometers. The main outcome measure was outdoor time, measured by the WHO questionnaire and a 1-week diary., Results: Interim analysis at 6 months showed a significant increase in mean outdoor time per week in the intervention arm (14.75 h week(-1) ) compared to the control arm (12.40 h week(-1) ) as measured by the questionnaire (p = 0.04). However, greater outdoor time was not statistically significant at the end of the trial (15.95 h week(-1) vs 14.34 h in the control group (p = 0.29)., Conclusions: There was an increase in outdoor time for children in the incentive-based physical activity outdoor program after 6 months but not at the end of the trial. Further larger school trials with better compliance with the intervention and longer duration could be conducted to evaluate clinical outcomes such as myopic shifts., (© 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.)

Purpose: To estimate the economic cost of myopia among adults aged 40 years and older in Singapore., Methods: A substudy of 113 Singaporean adults aged 40 years and older with myopia (spherical equivalent refraction of at least -0.5 diopters) in the population-based ancillary study of Singapore Chinese Eye Study (SCES) was conducted. A health expenditure questionnaire was used to assess the direct cost of myopia., Results: A total of 113 (90.4%) of 125 myopic subjects participated in the survey. The mean cost was approximately SGD$900 (USD$709) per person per year. The lifetime per capita cost ranged from SGD$295 (USD$232) for those with 0 year's duration to SGD$21,616 (USD$17,020) for those with 80 years' duration. Costs of spectacles, contact lenses, and optometry services were the major cost drivers, contributing to an average of 65% of total costs. Seven subjects (6.2%) had undergone LASIK surgery, resulting in a cost of SGD$4891 (USD$3851) per patient per year. Three subjects (2.7%) reported annual costs of (SGD$33 or USD$26) for complications due to LASIK surgery or contact lenses. There was an increasing cost of myopia in adults who started to wear glasses at earlier ages. By applying our cost data to age-specific myopia prevalence data in the whole population in the country, the total cost was estimated to be approximately SGD$959 (USD$755) million per year in Singapore., Conclusions: Myopia is associated with substantial out-of-pocket expenditure, imposing considerable economic burden for patients. Myopia is a disorder with immense societal costs and public health impact.

Purpose: To examine if myopia is a risk factor for age-related cataract., Design: Systematic review and meta-analysis., Methods: A systematic review of the literature was performed using PubMed and Embase from their inception to March 2013 for population-based studies with data on myopia and age-related cataract, including nuclear, cortical, and posterior subcapsular (PSC) cataract. Separate meta-analyses for case-control/cross-sectional studies and cohort studies were conducted using random-effects models, with results reported as adjusted odds ratios (ORs) and relative risks (RRs), respectively., Results: A total of 38 007 subjects aged 30-97 years from 12 population-based studies were included in the meta-analysis. Meta-analysis of the 7 cross-sectional studies and 1 case-control study confirmed that myopia was associated with increasingly prevalent nuclear (pooled OR 2.81, 95% CI 1.94-4.06) and PSC cataract (pooled OR 1.93, 95% CI 1.49-2.49) but not with cortical cataract (pooled OR 1.08, 95% CI 0.90-1.30). Meta-analysis from 3 or 4 cohort studies showed nonsignificant associations of myopia with incident nuclear (pooled RR 1.25, 95% CI 0.71-2.21), cortical (pooled RR 1.21, 95% CI 0.67-2.19), and PSC cataract (pooled RR 1.26, 95% CI 0.92-1.74)., Conclusions: The associations of myopia with prevalent nuclear and PSC cataract are confirmed in meta-analysis of 8 study findings. The association of myopia with incidence of age-related cataract could not be confirmed in meta-analysis of 4 study findings., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: To describe the associations of myopia and axial length (AL) with age-related cataract in an Asian population in Singapore., Methods: A population-based cross-sectional study that examined 3280 (78.7% response) adults of Malay ethnicity aged 40 to 80 years. Refractive error was determined by subjective refraction and AL was measured using the Zeiss IOL-Master. Digital slit lamp and retroillumination lens photographs were taken and graded for age-related nuclear, cortical, and posterior subcapsular (PSC) cataract following the Wisconsin system., Results: After excluding eyes with prior refractive or cataract surgery, 5474 eyes with gradable lens photographs were analyzed. In multivariate analyses adjusting for age, sex, body mass index, systolic blood pressure, glycosylated hemoglobin, smoking status, and education, myopia (spherical equivalent less than -0.5 diopter [D]) was associated with an increased prevalence of nuclear (OR: 4.99, 95% CI: 3.72–6.69) and PSC cataract (OR: 1.34, 95% CI: 1.30-1.39) but not with cortical cataract (OR: 0.85, 95% CI: 0.68-1.08) compared with emmetropia. Per-millimeter increase in AL was not associated with any of the three cataract subtypes. When myopia was defined as spherical equivalent of less than -5.0 D to -6.0 D, the OR of myopia for PSC cataract increased dramatically., Conclusions: Our study shows that myopia, but not AL, was associated with nuclear cataract, supporting the concept of index myopia with aging. Myopia, especially high myopia, may predispose to PSC cataract formation. Clinically, ophthalmologists should be aware that risk of PSC cataract appears to vary by refractive status.

Purpose: To determine the associations of myopia and axial length (AL) with major age-related eye diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), age-related cataract, and primary open-angle glaucoma (POAG)., Design: Population-based, cross-sectional study., Participants: A total of 3400 Indians (75.6% response rate) aged 40 to 84 years in Singapore., Methods: Refractive error was determined by subjective refraction, and AL was determined by noncontact partial coherence laser interferometry. Age-related macular degeneration and DR were defined from retinal photographs according to the Wisconsin Age-Related Maculopathy Grading System and Airlie House classification system, respectively. Age-related cataract was diagnosed clinically using the Lens Opacity Classification System (LOCS) III system. Glaucoma was defined according to International Society for Geographical and Epidemiological Ophthalmology criteria., Main Outcome Measures: Age-related macular degeneration, DR, age-related cataract, and POAG., Results: Myopic eyes (spherical equivalent [SE] <-0.5 diopter [D]) were less likely to have AMD (early plus late AMD) (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.25-0.79) or DR (OR, 0.68; 95% CI, 0.46-0.98) compared with emmetropic eyes; each millimeter increase in AL was associated with a lower prevalence of AMD (OR, 0.76; 95% CI, 0.65-0.89) and DR (OR, 0.73; 95% CI, 0.63-0.86). Myopic eyes were more likely to have nuclear (OR, 1.57; 95% CI, 1.13-2.20) and posterior subcapsular (OR, 1.73; 95% CI, 1.10-2.72) cataract, but not cortical cataract (P = 0.64); each millimeter increase in AL was associated with a higher prevalence of posterior subcapsular cataract (PSC) (OR, 1.29; 95% CI, 1.07-1.55), but not nuclear (P = 0.77) or cortical (P = 0.39) cataract. Eyes with high myopia (SE <-6.0 D) were more likely to have POAG (OR, 5.90; 95% CI, 2.68-12.97); each millimeter increase in AL was associated with a higher prevalence of POAG (OR, 1.43; 95% CI, 1.13-1.80)., Conclusions: Myopic eyes are less likely to have AMD and DR but more likely to have nuclear cataract, PSC, and POAG. The associations of myopia with AMD, DR, and POAG are mostly explained by longer AL. However, the association between myopia and nuclear cataract is explained by lens refraction rather than AL., (Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: We aimed to determine the relationship between puberty and growth spurts with peak spherical equivalent (SE) or axial length (AL) velocity in Singapore schoolchildren., Methods: In the Singapore Cohort Study of the Risk Factors for Myopia of 1779 schoolchildren, the longitudinal refractive and pubertal status of 892 boys and 887 girls from ages 6 to 14 years were assessed. The study sample included 1329 Chinese, 316 Malays, 114 Indians, and 20 children of other races. Information regarding puberty parameters, age of peak height velocity, age of menarche, and break of voice (BOV) was obtained. Peak velocity was defined as the greatest change in measurements over a period of 1 year. Tanner stage 1 for pubic hair or breast development, in boys and girls, respectively, at age 12 was categorized as "later puberty," whereas stages 2 to 5 corresponded to "earlier puberty." Refractive error was determined by cycloplegic autorefraction using the Canon RK-F5, and AL was measured using the A-scan biometry machine., Results: The children were examined annually, and the mean number of visits was 5.7 ± 1.3. Age of peak height velocity occurred earlier in girls than in boys (11.0 ± 1.2 vs. 12.0 ± 1.7 years, P < 0.001). Girls with earlier peak height velocity experienced peak AL velocity and peak SE velocity approximately half a year earlier than those with later puberty (mean age of 10.3 ± 1.6 vs. 10.8 ± 1.7 years, P < 0.001; and 10.0 ± 1.5 vs. 10.6 ± 1.25 years, P < 0.001, respectively). Similarly, boys who had earlier peak height velocity also achieved peak AL and peak SE velocity earlier than those who experienced later peak height velocity (mean age of 10.4 ± 1.6 vs. 11.1 ± 1.8 years, P < 0.001; and 10.1 ± 1.5 vs. 10.6 ± 1.7 years, P = 0.01). Both girls and boys who had early peak height velocity had earlier age of onset of myopia than those with later peak height velocity (9.7 ± 1.4 vs. 10.1 ± 1.5 years for girls, P = 0.04; and 9.9 ± 1.5 vs. 10.4 ± 1.6 years for boys, P = 0.03). Myopia progression, in terms of AL velocity, also occurred earlier in boys and girls with earlier peak height velocity (10.2 ± 1.5 vs. 11.0 ± 1.9 for boys, P < 0.001; and 10.2 ± 1.5 vs. 10.7 ± 1.7 for girls, P = 0.004, respectively). The associations were not significant when Tanner staging, age of menarche, or BOV was used to determine stage of puberty., Conclusions: Boys and girls with earlier peak height velocity experienced earlier peak SE and AL velocity, and age of myopia onset. Thus, variations in the onset and peak progression of myopia may be associated with height spurts.

Purpose: To assess the influence of factors related to migration and acculturation on myopia in migrant Indians in Singapore., Design: Population-based cross-sectional study., Methods: A total of 3400 Singaporean Indians (75.6% response rate) aged over 40 years participated in this study. Information regarding country of birth, migration age, and language of interview were collected from interviews. Indians born outside of Singapore were defined as "first-generation" immigrants, while Indians born in Singapore were defined as "second-generation (or higher)" immigrants. Refraction was determined by autorefraction and refined by subjective refraction. Ocular biometry including axial length (AL), anterior chamber depth (ACD), and corneal radius (CR) were measured by partial coherence interferometry. Myopia and high myopia were defined as spherical equivalents (SE) of less than -0.5 diopter (D) for myopia, and < -5 D for high myopia, respectively., Results: The prevalence of myopia (30.2% vs 23.4 %) and high myopia (4.8% vs 2.5%) were higher in second-generation immigrants compared with first-generation immigrants. Second-generation immigrants had longer AL (23.50 mm vs 23.37 mm, P = .004) than first-generation immigrants after multivariate adjustment. The excess prevalence of myopia was reduced by 37.5% but remained statistically significant (P = .02) after further controlling for educational level. Among first-generation immigrants, those migrating to Singapore before the age of 21 had significantly higher prevalence of myopia (odds ratio [OR]: 1.85; 95% confidence interval [CI]: 1.32, 2.59) and longer AL (regression coefficient: 0.27; 95% CI: 0.11, 0.43) than those migrating after 21 years of age. Also, first-generation immigrants interviewed in English had higher prevalence of myopia (OR: 1.46; 95% CI: 1.00, 2.17) than their non-English-interviewed counterparts., Conclusions: The prevalence of myopia among second-generation (or higher) Indian immigrants in Singapore is higher than first-generation immigrants. Country-specific environmental factors may be important for the increasing prevalence of myopia in Asia., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Myopia, the most common type of refractive error, is a complex trait including both genetic and environmental factors. Numerous studies have tried to elucidate the aetiology of myopia. However, the exact aetiology of myopia is still unclear., Purpose: To summarize the worldwide patterns and trends for the prevalence of myopia and to evaluate the risk factors for myopia in population-based studies., Recent Findings: The prevalences of myopia vary across populations of different regions and ethnicities. In population-based studies on children, the prevalence of myopia has been reported to be higher in urban areas and Chinese ethnicity. The regional and racial difference is not so obvious in adult populations aged over 40 years. More time spent on near work, less time outdoors, higher educational level and parental history of myopia have been reported to increase the risk of myopia., Conclusions: Environmental factors play a crucial role in myopia development. The effect of gene-environment interaction on the aetiology of myopia is still controversial with inconsistent findings in different studies. A relatively hyperopic periphery can stimulate compensating eye growth in the centre. Longitudinal cohort studies or randomized clinical trials of community-based health behaviour interventions should be conducted to further clarify the aetiology of myopia., (Ophthalmic & Physiological Optics © 2011 The College of Optometrists.)

Background: The aim of this study was to determine the prevalence of refractive errors and their association with glycaemic control among adults with type 2 diabetes mellitus (T2DM) in eastern China.Methods: A community-based survey, including 913 adults with T2DM aged 30 to 89 years, was conducted. Refractive error was assessed by autorefraction, after which subjective refraction was performed. Ocular biometric parameters were measured by non-contact partial coherence laser interferometry. Myopia was defined as spherical equivalent (SE) less than -0.50 dioptres (D), high myopia as SE less than -5.00 D, hyperopia as SE greater than 0.50 D and astigmatism as cylinder less than -0.50 D.Results: After excluding participants who had undergone cataract surgery, 839 were included in the data analyses and 96.1 per cent were found to have refractive errors. The overall prevalences of myopia, high myopia, hyperopia and astigmatism were 28.2 per cent (95 per cent confidence interval [CI] 25.2-31.3), 6.3 per cent (95 per cent CI 4.7-8.0), 46.4 per cent (95 per cent CI 43.0-49.7) and 81.0 per cent (95 per cent CI 78.4-83.7) with no gender differences observed (all p > 0.10). In multivariate analysis, myopia was associated with decreasing age (odds ratio [OR] = 0.86, p = 0.01; per year increase), higher blood levels of haemoglobin A1c (HbA1c ) (OR = 1.12, p = 0.05; per unit increase), higher education levels (OR = 5.10, p < 0.001; university or college versus illiterate or primary school) and the presence of nuclear cataract (OR = 2.36, p < 0.001).Conclusions: Refractive errors may be associated with glycaemic control among T2DM patients. Longitudinal analyses are warranted to examine the relationship between changes in HbA1c and the development of refractive errors. [ABSTRACT FROM AUTHOR]

Purpose To determine the prevalence, types and awareness of glaucoma in a rural community in China and to examine possible ethnic variations. Methods The Yunnan Minority Eye Study was a multi-ethnic community-based eye survey using random cluster sampling strategies. 2133 Bai, 2205 Han and 2208 Yi Chinese aged 50 years or older participated in this study. Glaucoma including primary open-angle glaucoma ( POAG), primary angle-closure glaucoma ( PACG) and secondary glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. Results The overall age-standardized prevalence of all glaucoma was 2.6% (95% confidence interval [ CI]: 2.2-3.1%) in this population. It was 1.8% (95% CI: 1.1-1.9%) for POAG and 0.5% (95% CI: 0.9-1.6%) for PACG, respectively. Among 29 people with secondary glaucoma, 27 (93%) were blind in at least one eye. The presence of primary open-angle glaucoma was associated with male gender (odds ratio [ OR] = 2.94; comparing men with women), Yi ethnicity ( OR = 2.27; comparing Yi with Han people), higher IOP ( OR = 1.09 per mmHg increase), and the presence of myopia ( OR = 1.84). Of the 212 participants with glaucoma, only 38 (18%) were aware of the disease and had been diagnosed previously as having glaucoma or suspected glaucoma. Patients who were better educated tended to be aware of the disease. Conclusions Significant ethnic difference in the prevalence of POAG was observed in this study. The low awareness of glaucoma highlights the pressing need to increase public awareness of this potentially blinding condition in rural China. [ABSTRACT FROM AUTHOR]

Purpose: To determine the association of season of birth and refractive error in very young Chinese children in China. Methods: We conducted a population-based study of Chinese children aged 0 to 3 years residing in eastern China. Refraction was determined by non-cyclopegic autorefraction using a hand-held autorefractor. Date of birth was retrieved from birth certificate of the individual subjects. A generalized linear regression model was fitted to estimate the regression coefficient and 95% confidence interval (CI) of refractive error for season of birth, adjusting for confounders. Results: Of the 1385 children eligible to participate, 1222 (88.2%) were examined. Refractive error data were available for 1219 children. The mean spherical equivalent were 1.21 diopters (D) in children born Spring, 1.24 D in those born in Summer, 1.23 D in those born in Autumn, 1.15 D in Winter. After adjusting for age, sex, father's educational level, birth weight and the number of summers between birth and examination date the children have been exposed to, children born in winter had a 0.12 D more myopic refraction compared with those born in summer (regression coefficient: −0.12; 95% CI, −0.27,−0.06; P = 0.006). The association between season of birth and cylinder power was not statistically significant. Conclusions: In China, children born in winter had a more myopic refraction compared with those born in other seasons. The observed association between season of birth and refractive error was independent of parental educational level and birth weight, suggesting that light level may have a small impact on refractive development in early life. [ABSTRACT FROM AUTHOR]

PURPOSE: To describe racial variations in the prevalence of refractive errors among adult white, Chinese, Hispanic, and black subjects in the United States. DESIGN: Cross-sectional data from a prospective cohort study--the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: A total of 6000 adults aged 45 to 84 years living in the United States participated in the study. Refractive error was assessed, without cycloplegia, in both eyes of all participants using an autorefractor. After excluding eyes with cataract, cataract surgery, or previous refractive surgery, the eye with the larger absolute spherical equivalent (SE) value for each participant was used to classify refractive error. Any myopia was defined as SE of -1.0 diopters (D) or less; high myopia was defined as SE of -5.0 D or less; any hyperopia was defined as SE of D1.0 D or more; clinically significant hyperopia was defined as SE of D3.0 D or more. Astigmatism was defined as a cylinder value of D1.0 D or more. RESULTS: After excluding 508 participants with cataracts in both eyes, 838 participants with cataract surgery, 90 participants with laser refractive surgery, and 134 participants who refused to remove their contact lenses for the refraction measurement, 4430 adults with refractive error assessment in at least 1 eye contributed to the analysis. The prevalence of myopia among MESA participants was 25.1%, with lowest rates in Hispanic participants (14.2%), followed by black (21.5%) and white participants (31.0%), and highest rates in Chinese participants (37.2%). The overall rates of high myopia and astigmatism were 4.6% and 45.0%, respectively, with Chinese subjects also having the highest rates of high myopia (11.8%) and astigmatism (53.4%). The overall prevalence of any hyperopia was 38.2% and clinically significant hyperopia was 6.1%, with Hispanic participants having the highest rates of hyperopia (50.2%) and clinically significant hyperopia (8.8%). In multivariate analyses adjusting for age, sex, race, and study site, higher education level, being employed, and being taller were associated with a higher prevalence of myopia. In contrast, lower educational level and being shorter were associated with a higher prevalence of hyperopia. CONCLUSIONS: Myopia and astigmatism were most prevalent in the Chinese population, with Chinese subjects having 3 times the prevalence of myopia as Hispanic subjects. Hyperopia was most common in Hispanic subjects. These findings provide further insights into variations in refractive errors among different racial groups and have important implications for the eye care services in the United States. [ABSTRACT FROM AUTHOR]

PURPOSE: To examine the pattern of myopia-related macular and optic disc changes in Singapore adults with high myopia (spherical equivalent ≤-6.00 diopters). DESIGN: Asian adults with high myopia from 3 population-based surveys. METHODS: Adults 40 years and older (n = 359) with high myopia were pooled from 3 population-based surveys in Singapore Asians: (1) the Singapore Prospective Study Program (SP2, n = 184); (2) the Singapore Malay Eye Study (SiMES, n = 98); and (3) the Singapore Indian Eye Study (SINDI, n = 77). All study participants underwent standardized refraction and fundus photography, and SiMES and SINDI subjects also completed ocular biometry measurements. Myopia-related macular (posterior staphyloma, lacquer cracks, Fuchs spot, myopic chorioretinal atrophy, and myopic choroidal neovascularization) and optic disc (optic nerve head tilt, optic disc dimensions, and peripapillary atrophy) changes were evaluated. RESULTS: The most common myopia-related macular finding in adults with high myopia was staphyloma (23%), followed by chorioretinal atrophy (19.3%). There were few cases of lacquer crack (n = 6, 1.8%), T-sign (n=6, 1.8%), retinal hemorrhage (n=3, 0.9%), active myopic choroidal neovascularization (n = 3, 0.9%), and no case of Fuchs spot. The most common disc finding associated with high myopia was peripapillary atrophy (81.2%), followed by disc tilt (57.4%). Staphyloma and chorioretinal atrophy increased in prevalence with increasing age, increasing myopic refractive error, and increasing axial length (all P<.001). Ethnicity comparisons demonstrated the highest proportion of staphyloma (P = .04) among Malays, the highest proportion of peripapillary atrophy (P = .01) and disc tilt (P<.001) among Chinese, and the largest cup-to-disc ratio (P<.001) among Indians. CONCLUSIONS: Staphyloma and chorioretinal atrophy lesions were the most common fundus findings among Asian adults with high myopia. In this population, tilted discs and peripapillary atrophy were also common, while choroidal neovascularization and Fuchs spot were rare. In contrast with Singapore teenagers, in whom tilted disc and peripapillary atrophy were common while staphyloma and chorioretinal atrophy were rare, pathologic myopia appears to be dependent on the duration of disease and, thus, age of the individual. [ABSTRACT FROM AUTHOR]