A cluster randomised controlled trial evaluating an incentive-based outdoor physical activity programme to increase outdoor time and prevent myopia in children

Financial Incentives for Physical Activity and Sports Participation in Young People

Physical inactivity is a global health problem. Childhood is an opportune time to establish healthy physical activity behaviors, including the participation in organized physical activity, such as sports. We hypothesize that financial incentives can improve young people's participation in physical activity and sports. The design of the incentive and the context in which it operates are crucial to its success.

Interventions to increase time spent outdoors for preventing incidence and progression of myopia in children

BACKGROUND

Myopia or nearsightedness is a type of refractive error. It causes people to see near objects clearly but distant objects as blurred. Good vision can be obtained if the refractive error is corrected properly but, where this is not possible, impaired vision will remain. The remaining myopia imposes a considerable personal and societal burden. In addition, the progression of myopia is more likely to be accompanied by other ocular diseases such as cataract, glaucoma and retinal detachment. Myopia has emerged as a significant global public health problem in recent years. The World Health Organization (WHO) reported uncorrected or undercorrected myopia to be a major cause of visual impairment worldwide. From both an individual and social perspective, it is important to prevent the onset of myopia and slow down its progression. Observational studies have shown that children who spend more time outdoors have a lower incidence of myopia. Several other non-Cochrane systematic reviews have focused on the association between increasing children's outdoor activity time and the prevention of myopia. However, none of these systematic reviews were limited to randomised controlled trials (RCTs), as they included all types of study designs, including observational studies and non-RCTs, in addition to RCTs.

OBJECTIVES

To assess the effects of interventions to increase outdoor time on the incidence and progression of myopia in children.

SEARCH METHODS

We searched CENTRAL, MEDLINE Ovid, Embase Ovid, ISRCTN registry, ClinicalTrials.gov, and the WHO ICTRP with no language restrictions. The databases were last searched on 24 June 2022.

SELECTION CRITERIA

We included RCTs and cluster-RCTs in which interventions were performed to increase the outdoor time for children with the aim of preventing the incidence and progression of myopia.

DATA COLLECTION AND ANALYSIS

We employed the standard methods recommended by Cochrane and assessed the certainty of the evidence using GRADE. We considered the following outcome measures: mean change in refractive error from baseline, incidence of myopia, mean change in the axial length from baseline, mean change in unaided distance visual acuity from baseline, quality of life and adverse event.

MAIN RESULTS

We included five RCTs in this review, four of which were cluster-RCTs. The total number of participants was 10,733. The included participants were primary school children, most of whom were in first or second grade (aged six to nine years). Four cluster-RCTs involved school-based interventions to encourage children to spend more time outdoors. The interventions included classroom time outdoors, routine for spending recess outdoors, motivational tools for spending time outdoors, and encouragement through electronic information tools. The intervention groups had less change in refractive errors in the direction of myopia; however, 95% confidence intervals (CIs) included no benefit or both benefit and harm at years one and three, and differences at year two included both clinically important and unimportant benefits (at 1 year: mean difference (MD) 0.08 dioptres (D), 95% CI -0.01 to 0.17; 4 studies, 1656 participants; low-certainty evidence; at 2 years: MD 0.13 D, 95% CI 0.06 to 0.19; 4 studies, 2454 participants; moderate-certainty evidence; at 3 years: MD 0.17 D, 95% CI -0.17 to 0.51; 1 study, 729 participants; low-certainty evidence). Our protocol defined a difference of 0.1 D in the change in refractive error as clinically important. At one year, the difference was less than 0.1 D, but at two and three years it was more than 0.1 D. The incidence of myopia was lower in the intervention groups compared to the control groups, but 95% CIs included no change or clinically unimportant benefits (at 1 year: 7.1% with intervention versus 9.5% with control; risk ratio (RR), 0.82, 95% CI 0.56 to 1.19; 3 studies, 1265 participants; low-certainty evidence; at 2 years: 22.5% with intervention versus 26.7% with control; RR 0.84, 95% CI 0.72 to 0.98; 3 studies, 2104 participants; moderate-certainty evidence; at 3 years: 30.5% with intervention versus 39.8% with control; RR 0.77, 95% CI 0.59 to 1.01; 1 study, 394 participants; moderate-certainty evidence). Our protocol defined a difference of 3% in the incidence of myopia as clinically important. At one year, the difference was 2.4%, but there were clinically important differences between the two groups at two (4.2%) and three years (9.3%). The intervention groups had smaller changes in axial lengths in the direction of myopia than the control groups; however, 95% CIs included no benefit or both benefit and harm at years one and three (at 1 year: MD -0.04 mm, 95% CI -0.09 to 0; 3 studies, 1666 participants; low-certainty evidence; at 2 years: MD -0.04 mm, 95% CI -0.07 to -0.01; 3 studies, 2479 participants; moderate-certainty evidence; at 3 years: MD -0.03 mm, 95% CI -0.13 to 0.07; 1 study, 763 participants; moderate-certainty evidence). No included studies reported changes in unaided distance visual acuity and quality of life. No adverse events were reported.

AUTHORS' CONCLUSIONS

The intervention methods varied from adopting outdoor activities as part of school lessons to providing information and motivation for encouraging outdoor activities. The results of this review suggest that long-term interventions to increase the time spent outdoors may potentially reduce the development of myopia in children. However, although the interventions may also suppress the progression of myopia, the low certainty of evidence makes it difficult to draw conclusions. Further research needs to be accumulated and reviewed.

Effect of mount location on the quantification of light intensity in myopia study

PURPOSE

To investigate how the mounting location of wearable devices affects the measurement of light intensity.

METHODS

Two commercially available wearable devices, HOBO and Clouclip, were used to compare the effects of different mount locations on light intensity measurement. We assessed the consistency of the measurements of the two devices by placing a HOBO and a Clouclip simultaneously in 26 different light environments and measuring the light intensity. To simulate the real-life usage scenarios of the two devices, we had 29 participants wear two HOBOs-one on the wrist and the other on the chest-along with a Clouclip on their spectacles for 1 day; meanwhile, the light intensity was measured and analysed.

RESULTS

When under the same light environments, the light intensity measured by the Clouclip was 1.09 times higher than that by the HOBO, with an additional 82.62 units (r2=1.00, p<0.001). When simulating the real-life scenarios, the mean light intensity at the eye-level position was significantly lower than that at the chest position (189.13±665.78 lux vs 490.75±1684.29 lux, p<0.001) and the wrist position (189.13±665.78 lux vs 483.87±1605.50 lux, p<0.001). However, there was no significant difference in light intensity between the wrist and chest positions (483.87±1605.50 lux vs 490.75±1684.29 lux, p=1.00). Using a threshold of 1000 lux for outdoor exposure, the estimated light exposure at the eye-level position was significantly lower than that at the chest position (3.9% vs 7.8%, χ2=266.14, p<0.001) and the wrist position (3.9% vs 7.7%, χ2=254.25, p<0.001).

CONCLUSIONS

Our findings revealed significant variations in light exposure among the wrist, chest and eye position. Therefore, caution must be exercised when comparing results obtained from different wearable devices.

Artificial intelligence and digital solutions for myopia

Myopia as an uncorrected visual impairment is recognized as a global public health issue with an increasing burden on health-care systems. Moreover, high myopia increases one's risk of developing pathologic myopia, which can lead to irreversible visual impairment. Thus, increased resources are needed for the early identification of complications, timely intervention to prevent myopia progression, and treatment of complications. Emerging artificial intelligence (AI) and digital technologies may have the potential to tackle these unmet needs through automated detection for screening and risk stratification, individualized prediction, and prognostication of myopia progression. AI applications in myopia for children and adults have been developed for the detection, diagnosis, and prediction of progression. Novel AI technologies, including multimodal AI, explainable AI, federated learning, automated machine learning, and blockchain, may further improve prediction performance, safety, accessibility, and also circumvent concerns of explainability. Digital technology advancements include digital therapeutics, self-monitoring devices, virtual reality or augmented reality technology, and wearable devices - which provide possible avenues for monitoring myopia progression and control. However, there are challenges in the implementation of these technologies, which include requirements for specific infrastructure and resources, demonstrating clinically acceptable performance and safety of data management. Nonetheless, this remains an evolving field with the potential to address the growing global burden of myopia.

Effect of nature prescriptions on cardiometabolic and mental health, and physical activity: a systematic review

Nature prescriptions are gaining popularity as a form of social prescribing in support of sustainable health care. This systematic review and meta-analysis aims to synthesise evidence on the effectiveness of nature prescriptions and determine the factors important for their success. We searched five databases from inception up to July 25, 2021. Randomised and non-randomised controlled studies featuring a nature prescription (ie, a referral or an organised programme, by a health or social professional, to encourage spending time in nature) were included. Two reviewers independently conducted all steps of study selection; one reviewer collected summary data from published reports and conducted the risk of bias assessment. Random-effect DerSimonian-Laird meta-analyses were conducted for five key outcomes. We identified 92 unique studies (122 reports), of which 28 studies contributed data to meta-analyses. Compared with control conditions, nature prescription programmes resulted in a greater reduction in systolic blood pressure (mean difference -4·82 mm Hg [-8·92 to -0·72]) and diastolic blood pressure (mean difference -3·82 mm Hg [-6·47 to -1·16). Nature prescriptions also had a moderate to large effect on depression scores (post-intervention standardised mean difference -0·50 [-0·84 to -0·16]; change from baseline standardised mean difference -0·42 [-0·82 to -0·03]) and anxiety scores (post-intervention standardised mean difference -0·57 [-1·12 to -0·03]; change from baseline standardised mean difference -1·27 [-2·20 to -0·33]). Nature prescriptions resulted in a greater increase in daily step counts than control conditions (mean difference 900 steps [790 to 1010]) but did not improve weekly time of moderate physical activity (mean difference 25·90 min [-10·26 to 62·06]). A subgroup analysis restricted to studies featuring a referring institution showed stronger effects on depression scores, daily step counts, and weekly time of moderate physical activity than the general analysis. Beneficial effects on anxiety and depression scores were mainly provided by interventions involving social professionals whereas beneficial effects on blood pressures and daily step counts were provided mainly by interventions involving health professionals. Most studies have a moderate to high risk of bias. Nature prescription programmes showed evidence of cardiometabolic and mental health benefits and increases in walking. Effective nature prescription programmes can involve a range of natural settings and activities and can be implemented via social and community channels, in addition to health professionals.

Refractive Errors and Their Associated Factors in Schoolchildren: A Structural Equation Modeling

PURPOSE

To determine the prevalence of myopia and hyperopia in Shahroud schoolchildren and their risk factors.

METHODS

Optometric examinations including the measurement of uncorrected and corrected visual acuity as well as non-cycloplegic and cycloplegic refraction using retinoscopy were done for students. Generalized Structural Equation Modeling (GSEM) was used to determine direct and indirect effects of independent variables on myopia and hyperopia.

RESULTS

The data of 5581 students with a mean age of 9.24 ± 1.7 years were used in this study. The prevalence of myopia was 5.0% (95%CI: 4.3-5.7) and the prevalence of hyperopia was 4.8% (95%CI: 4.0 - 5.5) in all schoolchildren. According to the GSEM results, the odds of myopia in rural areas were 0.55 compared to urban areas. A one-unit increase in the ocular AL increased the odds of myopia by 4.91 times. The interaction of sex and age on myopia was significant such that in girls, the odds of myopia increased by 20% for every one-year increase in age while no significant change was seen in boys. A one-unit increase in the ocular AL decreased the odds of hyperopia by 0.49 times. Moreover, the interaction of outdoor activity hours and sex on the prevalence of hyperopia was significant such that increased outdoor activity reduced the odds of hyperopia in girls while no significant correlation was found in boys.

CONCLUSION

Myopia and hyperopia had moderate prevalence. Axial Length had the largest direct association on myopia and hyperopia. Age and outdoor activity had weak associations on refractive errors.

Determinants of Outdoor Time in Children and Youth: A Systematic Review of Longitudinal and Intervention Studies

Spending more time outdoors can improve children's social and cognitive development, physical activity, and vision. Our systematic review summarized the determinants of outdoor time (OT) based on the social-ecological model. We searched nine databases: MEDLINE, APA PsycINFO, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, SPORTDiscus, ERIC, SocINDEX, and ProQuest Dissertations and Theses. To be included, studies needed to be quantitative and longitudinal, include ≥1 potential determinant of OT among 0- to 17-year-olds, and be published in English, French, Japanese, or Spanish. We extracted the authors, publication year, country, design, sample size, OT measures, follow-up period, potential determinants, main results, and potential moderators or mediators. Fifty-five studies examining 119 potential determinants met the inclusion criteria. OT was consistently higher in warmer seasons and among participants reporting more OT at baseline. All three interventions that included both parent sessions and additional resources to promote OT (e.g., specific advice and community guides) were effective. COVID-19 restrictions and sun safety interventions discouraging midday outdoor activities led to less OT. The quality of evidence was rated as weak for 46 studies. Most potential determinants were examined in ≤3 studies; thus, more longitudinal studies are needed to enable stronger conclusions about the consistency of evidence and meta-analyses.

Effect of Text Messaging Parents of School-Aged Children on Outdoor Time to Control Myopia: A Randomized Clinical Trial

IMPORTANCE

Myopia in school-aged children is a public health issue worldwide; consequently, effective interventions to prevent onset and progression are required.

OBJECTIVE

To investigate whether SMS text messages to parents increase light exposure and time outdoors in school-aged children and provide effective myopia control.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted in China from May 2017 to May 2018, with participants observed for 3 years. Of 528 965 primary school-aged children from Anyang, 3113 were randomly selected. Of these, 268 grade 2 schoolchildren were selected and randomly assigned to SMS and control groups. Data were analyzed from June to December 2021.

INTERVENTIONS

Parents of children in the SMS group were sent text messages twice daily for 1 year to take their children outdoors. All children wore portable light meters to record light exposure on 3 randomly selected days (2 weekdays and 1 weekend day) before and after the intervention.

MAIN OUTCOMES AND MEASURES

The co-primary outcomes were change in axial length (axial elongation) and change in spherical equivalent refraction (myopic shift) from baseline as measured at the end of the intervention and 3 years later. A secondary outcome was myopia prevalence.

RESULTS

Of 268 grade 2 schoolchildren, 121 (45.1%) were girls, and the mean (SD) age was 8.4 (0.3) years. Compared with the control group, the SMS intervention group demonstrated greater light exposure and higher time outdoors during weekends, and the intervention had significant effect on axial elongation (coefficient, 0.09; 95% CI, 0.02-0.17; P = .01). Axial elongation was lower in the SMS group than in the control group during the intervention (0.27 mm [95% CI, 0.24-0.30] vs 0.31 mm [95% CI, 0.29-0.34]; P = .03) and at year 2 (0.39 mm [95% CI, 0.35-0.42] vs 0.46 mm [95% CI, 0.42-0.50]; P = .009) and year 3 (0.30 mm [95% CI, 0.27-0.33] vs 0.35 mm [95% CI, 0.33-0.37]; P = .005) after the intervention. Myopic shift was lower in the SMS group than in the control group at year 2 (-0.69 diopters [D] [95% CI, -0.78 to -0.60] vs -0.82 D [95% CI, -0.91 to -0.73]; P = .04) and year 3 (-0.47 D [95% CI, -0.54 to -0.39] vs -0.60 D [95% CI, -0.67 to -0.53]; P = .01) after the intervention, as was myopia prevalence (year 2: 38.3% [51 of 133] vs 51.1% [68 of 133]; year 3: 46.6% [62 of 133] vs 65.4% [87 of 133]).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, SMS text messages to parents resulted in lower axial elongation and myopia progression in schoolchildren over 3 years, possibly through increased outdoor time and light exposure, showing promise for reducing myopia prevalence.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR-IOC-17010525.

A Systematic Review of Physical Activity Intervention Programs in ASEAN Countries: Efficacy and Future Directions

A systematic review was conducted on the efficacy of interventions to improve physical activity. PubMed, Scopus and Web of Science were scanned for eligible studies published from 1978 to August 2021, resulting in a total of 52 relevant studies for review. The Downs and Black checklist was used as a quality assessment ool for a risk of bias assessment. The 52 studies were then broadly categorised into three major approach types: informational, behavioural and/or social, as well as direct. Within each major approach, studies were further sub-categorised into more specific intervention types before being assessed for their efficacy and applicability. Overall, the intervention types that seemed to be the most efficacious in increasing physical activity levels were those that involved home-based information provision, community-wide campaigns, incentivised change, individually adapted health behaviour programs, family-based social support interventions and the provision of self-monitoring tools. However, the results must be interpreted holistically, as many of the successful interventions included more than one approach type and success is likely contingent on effectively addressing several concurrent facets. The systematic review is registered on PROSPERO. Registration number: 282752.

mHealth interventions targeting movement behaviors in Asia: A scoping review

mHealth interventions can promote healthy movement behaviors (physical activity, sedentary behavior, and sleep). However, recent reviews include few studies from Asia, despite it being home to over 60% of the world population. The aim is to map the current evidence for mHealth interventions targeting movement behaviors in Asia. Six databases were searched up until August 2021. Included studies described an mHealth intervention targeting one or more movement behaviors, delivered in a country/territory in Asia, to a general population. A total of 3986 unique records were screened for eligibility in duplicate. Eighty studies with 1,413,652 participants were included. Most were randomized (38.8%) or quasi-experimental (27.5%) trials. Studies were from 17 countries/territories (out of 55); majority were high- (65.0%) or upper middle-income (28.7%). Physical activity was targeted most often (93.8%), few targeted sedentary behavior (7.5%), or sleep (8.8%). Most targeted one movement behavior (90.0%), and none targeted all three together. Interventions typically incorporated a single mHealth component (70.0%; app, pedometer, text messages, wearable) and were delivered remotely (66.3%). The average intervention length was 121.8 (SD 127.6) days. mHealth interventions in Asia have primarily targeted physical activity in high- and upper middle-income countries. There are few interventions targeting sedentary behavior or sleep, and no interventions in low-income countries.

Low Serum Vitamin D Is Not Correlated With Myopia in Chinese Children and Adolescents

Purpose

This cross-sectional study investigated the association between serum 25-hydroxyvitamin D [25(OH)D] concentration and myopia in two groups of Chinese children aged 6–14 years from different geographic and economic locations.

Methods

A total of 294 children from a lowland area and 89 from a highland area were enrolled as two groups of study subjects. The visual acuity, ocular biometry, and automated refraction were measured. The serum level of 25(OH)D was determined by chemiluminescence immunoassay. Near vision and outdoor exposure durations were assessed with a questionnaire interview. Data were analyzed for differences using Chi-square and Wilcoxon rank sum tests. The risk factors were evaluated using logistic regression analysis.

Results

We found that the serum level of 25(OH)D of the subjects from lowland area was 20.9 ng/mL which was higher than that of subjects from highland area (16.9 ng/mL). The median spherical equivalent refraction (SER) was −0.25 diopters(D) in lowland subjects and −0.63D in highland subjects. The prevalence of myopia was 45.2% in lowland subjects and 55.1% in highland subjects. The average axial length was similar, 23.6 mm and 23.1 mm in lowland and highland subjects, respectively. We found no statistical difference between the average SER and serum 25(OH)D concentration in subjects of either lowland or highland area. The ratio of myopia to non-myopia was also similar in subjects with three levels (sufficient, deficient, and insufficient) of serum 25(OH)D in these two areas.

Conclusions

There is no association between serum 25(OH)D concentration and myopia in the 6–14 years old Chinese children.

Interactions between genetic variants and near-work activities in incident myopia in schoolchildren: a 4-year prospective longitudinal study

CLINICAL RELEVANCE

Knowledge of interactions between genetic variants and near-work activities at the onset of myopia can facilitate health education regarding myopia.

BACKGROUND

To investigate the interactions between genetic variants (PDE10A, AREG and GABRR1) and near-work activities in the onset of myopia in southeastern Chinese school children.

METHODS

A total of 458 non-myopic, grade 1 children aged 6-7 years were included in a 4-year follow-up examination; 409 children were assessed further. Manifest (non-cycloplegic) refraction and axial length (AL) were measured every year, and questionnaires were administered annually to assess information regarding the demographic characteristics of children, near-work activities, outdoor exposure and parental myopia. Oral mucosa was collected in the last year of follow-up, and Sanger sequencing was used to genotype single nucleotide polymorphisms (SNPs) in DNA.

RESULTS

The cumulative change in the spherical equivalent refraction (SER) over 4 years was -1.20 ± 1.00 D, and the proportion of children with incident myopia was 42.9%. Multivariate logistic regression analysis showed that an increased amount of time spent doing homework (>2 h/d) was an independent risk factor for incident myopia. The PDE10A rs12206610CT genotype and spending > 5 h/d on near-work activities showed an interaction for incident myopia (OR = 4.29, 95% CI: 1.27-14.53; P_interaction = 0.02); moreover, the rs12206610CT genotype carriers who used electronic devices for > 1 h/d displayed an increased risk of incident myopia (OR = 3.43, 95% CI: 1.07-11.01; P_interaction = 0.043).

CONCLUSIONS

The rs2206610CT genotype carriers with near-work activities of >5 h/d were more likely to show incident myopia, especially those who used electronic devices >1 h/d. However, interactions between the rs12206610 SNP and near-work activities require further verification in animal models and larger sample cohorts.

Prevalence, incidence, and risk factors for myopia among urban and rural children in southern China: protocol for a school-based cohort study

INTRODUCTION

Myopia is the common cause of reduced uncorrected visual acuity among school-age children. It is more prevalent in urban than in rural areas. Although many myopia studies have focused on the effect of urbanisation, it remains unclear how visual experience in urban regions could affect childhood myopia. This study aims to investigate the incidence and prevalence of myopia among school-age children in urban and rural settings, thereby identifying the environmental factors that affect the onset and progression of myopia.

METHODS AND ANALYSIS

A school-based cohort study will be conducted. We will enroll all first-grade students from an urban (10 primary schools) and a rural (10 primary schools) regions of Zhaoqing city, China. Over 3-year follow-up period, students will receive detailed eye examinations annually and complete questionnaires about living habits and environment. In a 5% random subsample of the cohort, physical activity, light intensity and eye-tracking data will be obtained using wearable devices, and high-resolution macular images will be obtained by optical coherence tomography (OCT). The primary outcome is incident myopia, defined as myopia (spherical equivalent refractive of at least -0.5D) detected during follow-up among those without myopia at baseline.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the ethics committee of the Zhongshan Ophthalmic Center (number: 2019KYPJ171). Study findings will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04219228.

Global disease burden of uncorrected refractive error among adolescents from 1990 to 2019

Background

To estimate the global disease burden of uncorrected refractive error (URE) among adolescents and assess the contributions of various risk factors to disability-adjusted life-years (DALYs) due to URE.

Methods

Global, regional and country-level DALY numbers and rates due to URE among adolescents were acquired from the Global Burden of Disease Study 2019 database. Human Development Index (HDI), Socio-Demographic Index (SDI) and other country-level data were obtained from other open databases as potential indicators. Regression analysis was used to evaluate associations between DALY rates among adolescents and potential predictors.

Results

Global DALYs due to URE among adolescents rose by 8% between 1990 and 2019 but moderately decreased by 4.8% during this period after adjusting for population size. Female adolescents showed higher DALY rates. DALY rates sharply increased from 5 to 9 years of age, then rose more slowly, reaching a plateau before 20 years of age. Country-level DALY rates in 2019 were positively associated with HDI, SDI, and urbanization rates but negatively correlated with primary school dropout rates. Higher disease burden of adolescents visually impaired from URE was associated with lower primary school dropout rates (β = − 0.257, 95% CI − 0.376 to − 0.138, P < 0.001) and higher urbanization rates (β = 0.257, 95% CI 0.067 to 0.256, P = 0.001).

Conclusions

Higher socioeconomic status, urbanization rates and education levels are associated with a heavier disease burden of URE among adolescents. The findings of this study can provide a reference for policy making on resource allocation for URE prevention and control in teenagers.

The effect of spatially-related environmental risk factors in visual scenes on myopia

Myopia, the most common refractive error, is estimated to affect over two billion people worldwide, especially children from East Asian regions. Children with early onset myopia have an increased risk of developing sight threatening complications in later life. In addition to the contribution of genetic factors, of which expression is controversially suggested to be subject to environmental regulation, various environmental factors, such as near-work, outdoor, and living environment, have also been determined to play significant roles in the development of refractive error, especially juvenile myopia. Cues from daily visual scenes, including lighting, spatial frequency, and optical defocus over the field of visual stimuli, are suggested to influence emmetropisation, thereby affecting myopia development and progression. These risk factors in visual scenes of the everyday life may explain the relationship between urbanicity and myopia prevalence. This review first summarises the previously reported associations between myopia development and everyday-life environments, including schooling, urban settings, and outdoors. Then, there is a discussion of the mechanisms hypothesised in the literature about the cues from different visual scenes of urbanicity in relation to myopia development.

Digital Screen Time During the COVID-19 Pandemic: Risk for a Further Myopia Boom?

PURPOSE

To review the impact of increased digital device usage arising from lockdown measures instituted during the COVID-19 pandemic on myopia and to make recommendations for mitigating potential detrimental effects on myopia control.

DESIGN

Perspective.

METHODS

We reviewed studies focused on digital device usage, near work, and outdoor time in relation to myopia onset and progression. Public health policies on myopia control, recommendations on screen time, and information pertaining to the impact of COVID-19 on increased digital device use were presented. Recommendations to minimize the impact of the pandemic on myopia onset and progression in children were made.

RESULTS

Increased digital screen time, near work, and limited outdoor activities were found to be associated with the onset and progression of myopia, and could potentially be aggravated during and beyond the COVID-19 pandemic outbreak period. While school closures may be short-lived, increased access to, adoption of, and dependence on digital devices could have a long-term negative impact on childhood development. Raising awareness among parents, children, and government agencies is key to mitigating myopigenic behaviors that may become entrenched during this period.

CONCLUSION

While it is important to adopt critical measures to slow or halt the spread of COVID-19, close collaboration between parents, schools, and ministries is necessary to assess and mitigate the long-term collateral impact of COVID-19 on myopia control policies.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Association of multimedia teaching with myopia: A national study of school children

AIM

The aim of this study was to determine whether students' exposure to digitally projected, multimedia teaching material under naturally varying classroom lighting conditions is associated with myopia risk and severity.

DESIGN

A population-based, cross-sectional study in 2012 of children in grades 4-6 across 87 schools in Taiwan.

METHODS

Students (N = 3,686) reported demographic information, outdoor time, physical activity and near work. Parents provided their myopia status. Student-reported multimedia teaching frequency and classroom lighting levels were confirmed with direct observation. School nurses conducted vision screening and ophthalmologist referral. Myopia status and severity were measured by spherical equivalent refraction; SE ≤-0.5 dioptres was coded as myopic. Binary logistic and tobit regression were used to estimate the contributions of classroom multimedia exposure and lighting to myopia risk and severity controlling for risk factors.

RESULTS/FINDINGS

Age, parental myopia and hours of near work increased the odds of myopia and predicted greater severity. Physical activity and outdoor time predicted lower risk and severity. Multimedia exposure in relatively bright classrooms was associated with greater odds of myopia. Classroom lighting levels during multimedia teaching were inversely related to severity; exposure frequency was unrelated.

CONCLUSIONS

Multimedia exposure under brighter classroom conditions may contribute to the myopia incidence in schoolchildren.

IMPACT

Teaching with digital projection technology is increasingly prevalent. This may increase children's odds of developing myopia, which has far-reaching and lifelong deleterious effects. School nurses should raise awareness of and promote strategies that reduce this risk, including working with children, parents, school personnel and system leaders to adopt eye-healthy behaviours, practices and policies.

The Increasing Burden of Myopia in Israel among Young Adults over a Generation: Analysis of Predisposing Factors

PURPOSE

To determine the trends in prevalence of myopia in Israeli young adults over approximately a generation, as well as associated factors and variation in the impact of these factors on myopia prevalence in this region over time.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

One hundred four thousand six hundred eighty-nine consecutive persons 16 to 19 years of age born between 1971 and 1994 who had not yet enlisted in the Israeli Army but had completed the medical profiling process.

METHODS

Using data collected at a north Israel recruitment center, the prevalence of myopia over time was estimated, and a polynomial regression analysis was performed to assess significance of nonlinear trends. Associations of demographic and socioeconomic factors with myopia were assessed, and trends over time were analyzed using a factorial logistic regression.

MAIN OUTCOME MEASURES

The primary outcome measure was factors associated with the prevalence of myopia over time. The secondary outcome measure was a description of the change in prevalence of myopia over time.

RESULTS

The prevalence of myopia increased 1.284-fold over 24 years from 20.4% among participants born between 1971 and 1982 to 26.2% among participants born between 1983 and 1994. A quite similar increase was observed among males (from 17.9% to 22.7%, respectively) and females (from 23.9% to 30.8%, respectively). The factors found to be associated with myopia were as follows: more recent date of birth, female gender, more years of education, being the eldest child, non-Israeli ethnic origin, and urban residence. However, there were significant trends over time in the effects of some of these factors, most notably an attenuation of the difference between participants of different religions in the recent birth-years period. Most of these associations and trends were observed in both males and females separately, with some gender-specific variations. Immigrants from Ethiopia who were raised in Israel were highly more likely to demonstrate myopia than those who arrived at an older age.

CONCLUSIONS

This study demonstrated an increase in the prevalence of myopia and the possible associations of urbanization- and higher education-related factors among several subpopulations and the risk for myopia developing.

Interaction between lifestyle and genetic susceptibility in myopia: the Generation R study

Myopia is a refractive error of the eye caused by a complex interplay between nature and nurture. The aim of this study was to investigate whether environmental risk factors can influence the genetic effect in children developing myopia. A total of 3422 children participating in the birth-cohort study Generation R underwent an extensive eye examination at 9 years with measurements of refractive error and axial length corneal radius ratio (AL/CR). Environmental risk factors were evaluated using a questionnaire, and environmental risk scores (ERS) were calculated using backward regression analyses. Genetic risk scores (GRS) were calculated based on all currently known risk variants for myopia. Gene-environment interaction (G×E) was investigated using linear and logistic regression analyses. The predictive value of G×E and parental myopia was estimated using receiver operating characteristic curves. Myopia prevalence was 12%. Both GRS (P < 0.01) and ERS (P < 0.01) were significantly associated with myopia and AL/CR, as was G×E interaction (P < 0.01 for myopia; P = 0.07 for AL/CR). The predictive value of parental myopia was 0.67 (95% CI 0.65–0.70), similar to the values of GRS (0.67; 95% CI 0.64–0.70; P = 0.98) and ERS (0.69; 95% CI 0.66–0.72; P = 0.98). Adding G×E interaction significantly improved the predictive value to 0.73 (95% CI 0.70–0.75; P < 0.01). This study provides evidence that nature and nurture are equally important for myopia and AL/CR; however, the combination has the strongest influence. Since myopia genes are common in the population, adjustment of lifestyle should be a major focus in the prevention of myopia.

Patterns of Daily Outdoor Light Exposure in Australian and Singaporean Children

PURPOSE

Myopia is rising in prevalence in many locations, and there is evidence that outdoor light exposure is a major environmental factor playing a role in myopia development. This study examined the patterns of daily light exposure in similarly aged children from two geographic locations (Australia and Singapore) known to exhibit differences in myopia prevalence.

METHODS

Wearable light sensors were used to assess daily light exposure in 69 Singaporean children aged 8 to 12 years (mean, 9.2 ± 1.1) and 43 Australian children aged 10 to 12 years (mean, 11.3 ± 0.6). The mean daily time exposed to bright outdoor light (>1000 lux) and the number and duration of daily episodes of outdoor exposure were examined.

RESULTS

Patterns of daily outdoor light exposure differed substantially between Australia and Singapore. Australian children (105 ± 42 min/d) experienced significantly longer daily outdoor light exposure than Singaporean children (61 ± 40 min/d; P = 0.005), with the largest differences found on weekdays during school hours. Australian children (6.9 ± 1.5 episodes per day) had more frequent daily episodes of outdoor light exposure compared with Singaporean children (4.6 ± 1.5; P = 0.02); however, there was no significant difference in the mean duration of these episodes between countries (P = 0.54).

CONCLUSIONS

Children living in Singapore were exposed to significantly less daily outdoor light than Australian children, and these differences may be one of several factors contributing to the differences in myopia prevalence typically found between these populations.

TRANSLATIONAL RELEVANCE

Knowledge of these light exposure patterns may assist in the design of outdoor interventions, including school programs, to increase outdoor time in urban Asian populations.

The Influence of Environmental Factors on the Prevalence of Myopia in Poland

Purpose

In the paper, we describe and discuss the results of epidemiological studies concerning myopia carried out in Poland.

Materials and Methods

Results from the examination of 5601 Polish school children and students (2688 boys and 2913 girls) aged 6 to 18 years were analyzed. The mean age was 11.9 ± 3.2 years. Every examined student had undergone the following examinations: distance visual acuity testing, cover test, anterior segment evaluation, and cycloplegic retinoscopy after instillation of 1% tropicamide, and a questionnaire was taken.

Results

We have found that (1) intensive near work (writing, reading, and working on a computer) leads to a higher prevalence of myopia, (2) watching television does not influence the prevalence of myopia, and (3) being outdoors decreases the prevalence of myopia.

Conclusions

The results of our study point to insufficiency of accommodation contributing to the pathogenesis of myopia.

Strengthening teachers' abilities to implement a vision health program in Taiwanese schools

We designed a school-based, nationwide program called the 'New Era in Eye Health' to strengthen teacher training and to examine whether the existence of a government vision care policy influenced teachers' vision care knowledge and students' behavior. Baseline data and 3-month follow-up data were compared. A random sample of teachers (n = 660) from school vision health clusters in 22 cities/counties in Taiwan were invited to participate in our study and 436 agreed to participate (response rate = 66.1%). The mean age of participant teachers was 41.2 years, while the length of service mean was 14.6 years. For monitoring teacher outcomes, five cities/counties were selected as the intensely monitored group based on certain criteria. Sunlight diaries (n = 5434) were distributed and 3342 (61.5%) were returned. Teachers showed significant improvements in knowledge and behavior on the school vision health questionnaire. At the 3-month follow-up, the number of recesses as recorded by students' 'sunlight diary' increased. When teachers had better knowledge and behavior, recesses also increased. This study provided valuable insights to guide dissemination efforts for school vision health interventions and to help teachers implement research into their school vision health activities.

What Public Policies Should Be Developed to Cope with the Myopia Epidemic?

The epidemic of myopia in urban Asian cities has increased over recent generations and has become a significant public health concern. Considering the potential role of time outdoors in myopia prevention, and the differences in behavioral attitudes of individuals living in Urban East Asian (more indoor-centric) and Western countries, public policies should be developed in different countries accordingly to encourage children to go outdoors to counteract myopia. This is a short manuscript (presented at the International Myopia Conference-2015 by Prof. Seang Mei Saw) about public policies that should be developed to cope with the "myopia epidemic."

Reclaiming streets for outdoor play: A process and impact evaluation of "Juega en tu Barrio" (Play in your Neighborhood), an intervention to increase physical activity and opportunities for play

Background

New strategies are required to create supportive physical and social environments for children and promote active free-play. Juega en tu Barrio (JETB; Play in your Neighborhood) was designed and implemented to explore the effectiveness of closing a street in a low-to-middle income neighborhood in order to increase children’s outside play and physical activity.

Methods

A pretest-posttest design with control group was employed to investigate the intervention effects in a subsample of 100 children, 51 from the intervention neighborhood and 49 from the control neighborhood. The children wore pedometers for one week, and their parents completed questionnaires at two time points: before the intervention began and during the last two weeks of the intervention. JETB was conducted in the intervention neighborhood from 17:30 to 20:30, twice a week, from September to December 2014. Stewards ensured that the children were safe. Children and adults were assessed using systematic observation.

Results

The intervention and control neighborhoods included 177 and 116 children respectively. The average attendance per event was 60 children (SD = 22, reach 34%). In the intervention neighborhood, a significant increase between baseline and final assessment was observed in after-school outdoor playtime (p = 0.02), steps during the 3-hour intervention (p = 0.004), and daily steps Monday to Sunday (p = 0.006). Meanwhile, no changes were observed in the control neighborhood for the same variables. The proportion of children who met recommended daily step counts increased from 27.5% to 53.0% in the intervention neighborhood (p = 0.007), while for control neighborhood no difference was observed (49.0% to 53.0% p = 0.804).

Conclusions

JETB showed high community engagement while offering opportunities for increased outdoor play in children. The intervention showed a significant effect on the number of children meeting the daily pedometer-derived physical activity recommendations.

Development of the FitSight Fitness Tracker to Increase Time Outdoors to Prevent Myopia

Purpose

To develop a fitness tracker (FitSight) to encourage children to increase time spent outdoors. To evaluate the wear pattern for this tracker and outdoor time pattern by estimating light illumination levels among children.

Methods

The development of the FitSight fitness tracker involved the designing of two components: (1) the smartwatch with custom-made FitSight watch application (app) to log the instant light illuminance levels the wearer is exposed to, and (2) a companion smartphone app that synchronizes the time outdoors recorded by the smartwatch to smartphone via Bluetooth communication. Smartwatch wear patterns and tracker-recorded daily light illuminance levels data were gathered over 7 days from 23 Singapore children (mean ± standard deviation age: 9.2 ± 1.4 years). Feedback about the tracker was obtained from 14 parents using a three-level rating scale: very poor/poor/good.

Results

Of the 14 parents, 93% rated the complete “FitSight fitness tracker” as good and 64% rated its wearability as good. While 61% of 23 children wore the watch on all study days (i.e., 0 nonwear days), 26% had 1 nonwear day, and 4.5% children each had 3, 4, and 5 nonwear days, respectively. On average, children spent approximately 1 hour in light levels greater than 1000 lux on weekdays and 1.3 hours on weekends (60 ± 46 vs. 79 ± 53 minutes, P = 0.19). Mean number of outdoor “spurts” (light illuminance levels >1000 lux) per day was 8 ± 3 spurts with spurt duration of 34 ± 32 minutes.

Conclusion

The FitSight tracker with its novel features may motivate children to increase time outdoors and play an important role in supplementing community outdoor programs to prevent myopia.

Translational Relevance

If the developed noninvasive, wearable, smartwatch-based fitness tracker, FitSight, promotes daytime outdoor activity among children, it will be beneficial in addressing the epidemic of myopia.

Pilot survey of a novel incentive to promote healthy behavior among school children and their parents

Reversing the obesity epidemic has been a persistent global public health challenge, particularly among low socioeconomic status populations and racial/ethnic minorities. We developed a novel concept of community-based incentives to approach this problem in such communities. Applying this concept, we proposed a school intervention to promote obesity prevention in the U.S. We conducted a pilot survey to explore attitudes towards this future intervention. The survey was collected as a nonprobability sample (N = 137 school-aged children (5-12 years)) in northern California in July 2013. We implemented multivariable logistic regression analyses where the dependent variable indicated the intention to participate in the future intervention. The covariates included the body mass index (BMI) based weight categories, demographics, and others. We found that the future intervention is expected to motivate generally-high-risk populations (such as children and parents who have never joined a past health-improvement program compared to those who have completed a past health-improvement program (the odds-ratio (OR) = 5.84, p < 0.05) and children with an obese/overweight parent (OR = 2.72, p < 0.05 compared to those without one)) to participate in future obesity-prevention activities. Our analyses also showed that some subgroups of high-risk populations, such as Hispanic children (OR = 0.27, p < 0.05) and children eligible for a free or reduced price meal program (OR = 0.37, p < 0.06), remain difficult to reach and need an intensive outreach activity for the future intervention. The survey indicated high interest in the future school intervention among high-risk parents who have never joined a past health-improvement program or are obese/overweight. These findings will help design and implement a future intervention.

Assessing the Genetic Predisposition of Education on Myopia: A Mendelian Randomization Study

Myopia is the largest cause of uncorrected visual impairments globally and its recent dramatic increase in the population has made it a major public health problem. In observational studies, educational attainment has been consistently reported to be correlated to myopia. Nonetheless, correlation does not imply causation. Observational studies do not tell us if education causes myopia or if instead there are confounding factors underlying the association. In this work, we use a two-step least squares instrumental-variable (IV) approach to estimate the causal effect of education on refractive error, specifically myopia. We used the results from the educational attainment GWAS from the Social Science Genetic Association Consortium to define a polygenic risk score (PGRS) in three cohorts of late middle age and elderly Caucasian individuals (N = 5,649). In a meta-analysis of the three cohorts, using the PGRS as an IV, we estimated that each z-score increase in education (approximately 2 years of education) results in a reduction of 0.92 ± 0.29 diopters (P = 1.04 × 10(-3) ). Our estimate of the effect of education on myopia was higher (P = 0.01) than the observed estimate (0.25 ± 0.03 diopters reduction per education z-score [∼2 years] increase). This suggests that observational studies may actually underestimate the true effect. Our Mendelian Randomization (MR) analysis provides new evidence for a causal role of educational attainment on refractive error.

What Is the Relationship between Outdoor Time and Physical Activity, Sedentary Behaviour, and Physical Fitness in Children? A Systematic Review

The objective of this systematic review was to examine the relationship between outdoor time and: (1) physical activity, (2) cardiorespiratory fitness, (3) musculoskeletal fitness, (4) sedentary behaviour; or (5) motor skill development in children aged 3-12 years. We identified 28 relevant studies that were assessed for quality using the GRADE framework. The systematic review revealed overall positive effects of outdoor time on physical activity, sedentary behaviour, and cardiorespiratory fitness, although causality could not be assumed due to a lack of RCTs. Motor skill development was unrelated to outdoor time; however, this relationship was only examined in a single study of preschool children. No studies were found that examined associations between outdoor time and musculoskeletal fitness.

Clinical prediction of the need for interventions for the control of myopia

The prevalence of myopia is increasing in Western populations but in East Asian countries, it is increasing to epidemic levels, where there are also markedly increased rates of progression to pathological myopia. Measures to more effectively control the development and progression of myopia are urgently needed. Notwithstanding a large volume of research, especially regarding the different mechanisms for the development of myopia and the efficacy of particular methods of intervention, there is still a great need and scope for improvements in clinical efforts to prevent and/or control myopic progression. Too often clinical efforts may involve only one method of intervention; however, the heterogenous nature of myopia suggests that clinical intervention may be more successful when interventions are employed in combination. The decision to prescribe interventions for the control of myopia in children, especially prior to onset, may be better framed by a comprehensive estimation of the degree of risk for the development and/or progression of myopia. For example, rather than ascribing equal weight to any degree of parental myopia, more accurate estimates may be obtained, if risk is judged to increase with the degree of parental myopia and the extent of any associated degenerative pathology. Risk estimates may be limited to broad mild, moderate and severe classifications due to lack of accurate weighting of risk factors. Nevertheless, comprehensive assessment of risk factors appears likely to better inform a prognosis and discussions with parents. Consideration of numerous environmental influences, for example, such as continuity and intensity of near work and time spent outdoors, may contribute to better risk estimation. Family-based practice appears to be ideally suited for risk estimation and the clinical application of approaches to control myopia. A proactive approach to estimating risk of developing myopia prior to its onset may be beneficial. Earlier implementation of interventions to control myopia could significantly reduce the chance of progression to pathological myopia.