Survey on pattern of myopia in school children in Hangzhou after the COVID-19 pandemic: a school-based vision screening study.

BACKGROUND: Myopia is a major health issue around the world. Myopia in children has increased significantly during the COVID-19 pandemic in China, but reports are scarce on the prevalence of myopia following the pandemic. This study collected vision screening data of school children in China for five consecutive years to observe the changes in myopia after the pandemic and compare the observed prevalence of myopia before and after the pandemic. METHODS: A school-based vision screening study used stratified samplings to collect the vision screening data in school children aged 6-13 from 45 primary schools in Hangzhou. Vision screening data including uncorrected visual acuity(UCVA) and spherical equivalent refraction(SER). Calculating the mean of SER and the prevalence of myopia and hyperopia from 2019 to 2023. RESULTS: A total of 79,068 screening results (158,136 eyes) were included in the analysis. A substantial myopic shift (approximately -0.30 diopters [D] on average) was found in 2020 and 2021 compared with 2019 in all age groups and a substantial myopic shift (approximately 0.4 D on average) was found in 2022 compared with 2021. A slight myopic shift (approximately -0.14 D on average) was found in 2023 compared with 2022. The prevalence of myopia in all age groups was the highest for five years in 2020 or 2021, which was 31.3% for 6-year-olds, 43.0% for 7-year-olds, and 53.7% for 8-year-olds. A positive change in the prevalence rate of myopia was found at 6 years old (0.59%, 0.12%, 0.36%, 0.25%, p < 0.001). The change in prevalence rate in myopia was shifted slightly in children aged 10-13 years. Children aged 8 to 13 years had a slight increase in myopia prevalence from 2022 to 2023. The prevalence of hyperopia was low and stable in all grade groups, ranging from 0.7% to 2.2% over five years. CONCLUSION: Myopia in children has increased rapidly during the COVID-19 pandemic. After the pandemic, the prevalence of myopia in children gradually decreased temporarily and then rebounded. Myopic shift was more apparent in younger children. Myopic shift in children may be related to the reduction of outdoor time, less light, and near work habits, and further research is needed.

[Analysis of myopia status and related factors among primary school students in a certain district of Beijing City in 2022].

Objective: To analyze the current situation of myopia and its related factors among primary school students in a certain district of Beijing City in 2022, and provide a basis for the risk assessment of myopia among primary school students. Method: In June 2022, a cluster sampling method was used to include 376 third-grade students from a primary school in a certain district of Beijing. A questionnaire survey was conducted to collect basic information about students, including eye usage habits, reading and writing postures, and parents' myopia conditions. The examination of students' distant visual acuity and refractive status was performed. A multivariate logistic regression model was used to analyze the related factors of myopia occurrence. Results: The age of 376 primary school students was (8.87±0.417) years old, with 48.40% (182) being male. A total of 196 myopia cases were identified, with a myopia rate of 52.13%. The results of the multivariate logistic regression model analysis showed that students who sometimes read while lying down (OR=2.003, 95%CI: 1.128-3.555), often read while lying down (OR=18.853, 95%CI: 4.512-78.778), had outdoor activity time less than 120 minutes per day (OR=4.937, 95%CI: 2.4464-9.892), were engaged in indoor break activities (OR=4.995, 95%CI: 2.773-8.996), performed eye exercises less than once per day (OR=8.710, 95%CI: 4.464-16.995), had a reading distance from the book less than 30 cm (OR=5.098, 95%CI: 2.410-10.787), occasionally maintained a fist distance from the edge of the desk (OR=1.918, 95%CI: 1.086-3.385), and had high school desks and tables (OR=5.325, 95%CI: 1.465-19.359) could have a higher risk of myopia occurrence, compared with those who never read while lying down, had outdoor activity time more than 120 minutes per day, maintained outdoor break activities, performed eye exercises more than once per day, had a reading distance from the book more than 30 cm, always maintained a fist distance from the edge of the desk, and had short school desks and tables. Conclusion: The incidence rate of myopia among primary school students in a certain district of Beijing City. in 2022 is relatively high. The occurrence of myopia is related to insufficient outdoor activity time and poor eye usage habits.

Daylight and Electric Lighting in Primary and Secondary School Classrooms in the UK-An Observational Study.

Only a few recent studies report direct assessment or monitoring of light levels in the indoor learning environment, and no consensus exists on minimum exposures for children's health. For instance, myopia is a common progressive condition, with genetic and environmental risk factors. Reduced daylight exposure, electric lighting changes, increased near-work for school children, greater academic focus, and use of display screens and white boards may have important detrimental influences. Published assessment methods had varied limitations, such as incomplete compliance from participants wearing light loggers for extended periods. Climate-Based Daylight Modelling is encouraged in UK school design, but design approaches are impractical for post-occupancy assessments of pre-existing classrooms or ad hoc modifications. In this study, we investigated the potential for direct assessment and monitoring of classroom daylight and lighting measurements. Combined with objective assessments of outdoor exposures and class time use, the classroom data could inform design and light exposure interventions to reduce the various health impacts of inadequate daylight exposure. The relevant environmental measure for myopia depends on the hypothesized mechanism, so the illuminance, spectral distribution, and temporal light modulation from the electric lighting was also assessed.

Visual Impairment, Eye Conditions, and Diagnoses of Neurodegeneration and Dementia.

Importance: Vision and eye conditions are associated with increased risk for Alzheimer disease and related dementias (ADRDs), but the nature of the association and the underlying biological pathways remain unclear. If causal, vision would be an important modifiable risk factor with viable population-level interventions. Objective: To evaluate potentially causal associations between visual acuity, eye conditions (specifically cataracts and myopia), neuroimaging outcomes, and ADRDs. Design, Setting, and Participants: A cohort and 2-sample bidirectional mendelian randomization (MR) study was conducted using UK Biobank participants and summary statistics from previously published genome-wide association studies on cataract, myopia, and AD. The participants included in the analysis were aged 55 to 70 years without dementia at baseline (calendar years 2006 to 2010), underwent genotyping, and reported on eye conditions; a subset completed visual acuity examinations (n = 69 852-71 429) or brain imaging (n = 36 591-36 855). Data were analyzed from August 15, 2022, through November 28, 2023. Exposure: Self-reported cataracts, visual acuity, and myopia measured by refraction error. Main Outcomes and Measures: ADRD, AD, and vascular dementia were identified from electronic medical records. Total and regional brain volumes were determined using magnetic resonance imaging. Results: The sample included 304 953 participants (mean [SD] age, 62.1 (4.1) years; 163 825 women [53.72%]); 14 295 (4.69%) had cataracts and 2754 (3.86%) had worse than 20/40 vision. Cataracts (hazard ratio [HR], 1.18; 95% CI, 1.07-1.29) and myopia (HR, 1.35; 95% CI, 1.06-1.70) were associated with a higher hazard of ADRD. In MR analyses to estimate potential causal effects, cataracts were associated with increased risk of vascular dementia (inverse variance-weighted odds ratio [OR], 1.92; 95% CI, 1.26-2.92) but were not associated with increased dementia (OR, 1.21; 95% CI, 0.98-1.50). There were no associations between myopia and dementia. In MR for potential reverse causality, AD was not associated with cataracts (inverse variance-weighted OR, 0.99; 95% CI, 0.96-1.01). Genetic risk for cataracts was associated with smaller total brain (ß = -597.43 mm3; 95% CI, -1077.87 to -117.00 mm3) and gray matter (ß = -375.17 mm3; 95% CI, -680.10 to -70.24 mm3) volumes, but not other brain regions. Conclusions and Relevance: In this cohort and MR study of UK Biobank participants, cataracts were associated with increased risk of dementia, especially vascular dementia, and reduced total brain volumes. These findings lend further support to the hypothesis that cataract extraction may reduce the risk for dementia.

Prevalence and associated factors of myopia among adolescents aged 12-15 in Shandong Province, China: a cross-sectional study.

Myopia is a growing concern worldwide, especially among adolescents. This study aimed to investigate the prevalence and associated factors of myopia in adolescents aged 12-15 in Shandong Province, China. This cross-sectional study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines and involved stratified random cluster sampling of 128,678 students from 186 middle schools across 17 cities in Shandong Province. Data collection was conducted from March to April 2024. We excluded students with organic eye diseases, abnormal binocular vision functions, or a history of eye injuries or surgeries. Myopia was assessed using the standard logarithmic visual acuity chart and autorefractor without inducing ciliary muscle paralysis. A comprehensive questionnaire survey was conducted to gather demographic characteristics and daily life behaviors. With the chi-squared test for univariable analysis and multivariable logistic regression for identifying significant factors. This study included 126,375 participants, with a gender distribution of 51.02% male and 48.98% female. The overall prevalence of myopia was 71.34%. Higher prevalence was observed in girls (72.26%) compared to boys (70.45%), and the prevalence increased with age, peaking at 73.12% in 15-year-olds. Urban residents had a higher prevalence (71.86%) than rural (70.39%). Factors such as increased frequency of eye usage while lying down or leaning forward, frequent use of eyes while walking or riding in a car, prolonged screen time, and extended homework duration were associated with higher odds of developing myopia. Conversely, higher frequency of outdoor exercise, maintaining proper posture during reading and writing, greater distance from eyes to screen, and longer sleep duration were associated with lower odds. Additionally, female gender, older age, urban residence, and parental history of myopia increased the risk. The high prevalence of myopia among adolescents in Shandong Province was influenced by a combination of demographic, behavioral, and environmental factors. The study highlighted the importance of lifestyle modifications, such as increasing outdoor activities and maintaining proper visual habits, limiting the duration of screen exposure and homework sessions, and extending sleep duration, to mitigate the risk of developing myopia. These findings underscored the need for targeted public health interventions and educational campaigns to address this significant public health issue.

Crosstalk between Myopia and Inflammation: A Mini Review.

Myopia represents a significant public health concern worldwide, particularly affecting the ocular health of children and adolescents. The escalating prevalence of myopia in recent years underscores its urgency as a health issue among this demographic. Research indicates a profound connection between the onset of myopia, inflammatory processes and fibrosis. Individuals with inflammatory conditions like allergic conjunctivitis, choroiditis, systemic lupus erythematosus, and diabetes exhibit a heightened susceptibility to myopia. Conversely, myopic patients are at an increased risk of developing ocular inflammatory disorders, notably idiopathic multifocal choroiditis. We postulate that the expression of inflammatory markers, including NF-κB, TGF-ß, IL-1ß, IL-6, IL-8, and TNF-α, may contribute to the chronic inflammatory state observed in myopia. This paper highlights a substantial correlation between myopia and inflammation, suggesting the potential efficacy of anti-inflammatory agents in managing inflammation and slowing myopia progression.

Effects of physical activity patterns on myopia among children and adolescents: A latent class analysis.

BACKGROUND: The daily physical activity (PA) patterns of children and adolescents are intricate and ambiguous, with varying effects on myopia resulting from different combinations of PA. This study aims to scrutinize the spectrum of PA patterns among children and adolescents and assess their impact on myopia. METHODS: Data sourced from the 2014 National Student Physical Fitness Survey (Tianjin segment) encompassed PA records and visual acuity measurements of participants. Latent Class Analysis and a generalized linear model were employed to investigate the relationship between PA categories and visual acuity across different educational stages. RESULTS: The study comprised 6465 primary and middle school students, among whom 50.13% were male. PA patterns were categorized into high (27.16%), medium (29.88%) and low visual acuity regulation groups (13.97%) and the nonmainstream group (28.99%). Following adjustments for sex, age, region and BMI, the medium visual acuity regulation group exhibited a lower risk of myopia (OR = 0.617, 95% CI = 0.424-0.897, p = 0.012; OR = 0.654, 95% CI = 0.438-0.976, p = 0.038) compared to the nonmainstream group among junior and senior middle school students. CONCLUSION: The efficacy of diverse PA patterns in mitigating myopia risk varies across educational stages and is influenced by sex-specific factors. It is imperative to advance myopia management strategies by emphasizing tailored PA interventions, discerning between PA patterns and delivering timely guidance and interventions tailored to distinct educational stages and sexes.

Socioeconomic disparities and green space associated with myopia among Chinese school-aged students: A population-based cohort study.

Background: There is increasing evidence on the link between environmental factors and myopia in children and adolescents, yet with inconsistent conclusions. We investigated the associations between socioeconomic inequalities and green space with myopia in school-aged students participating in the Tianjin Child and Adolescent Research of Eye (TCARE) study. Methods: We obtained data from a population-based dynamic cohort study conducted in Tianjin, China, in 2021 and followed up in 2022. We included 1 245 271 participants from 16 districts with an average age of 11.6 years (standard deviation = 3.3) in our analysis. We synthesized their area-level SES through a prediction model that combined economic, educational, and health care variables and assessed the greenness levels surrounding the school using the Normalized Difference Vegetation Index (NDVI) based on data obtained through satellite remote sensing. We performed generalised linear mixed effects analyses for each myopia outcome separately, with adjustments for students' sex, years of education completed, and the school's geographical location. Results: We observed that students living in low SES areas had the highest prevalence of myopia (60.7%) in the last screening in 2022, as well as a higher incidence of one-year myopia (26.4%) compared to those residing in middle SES areas (22.7%). With a 0.1 increase in the 250, 500, and 1000 m buffer NDVI, the prevalence of myopia dropped by 6.3% (odds ratio (OR) = 0.937; 95% confidence interval (CI) = 0.915, 0.960), 7.7% (OR = 0.923; 95% CI = 0.900, 0.946), and 8.7% (OR = 0.913; 95% CI = 0.889, 0.937), respectively. The interaction analysis showed that low SES and low greenness exacerbate the prevalence of myopia. Findings from longitudinal analyses consistently demonstrated a correlation between higher values of NDVI and a slower progression of myopia. These findings remained robust across sensitivity analyses, including for variables on parental myopia and students' behaviors. Conclusions: Exposure to green spaces could play a crucial role in slowing the progression of myopia among school-aged students. Myopia control policies should prioritise young populations residing in low SES areas with limited access to green spaces, as they face the highest potential risks.

The association between screen time exposure and myopia in children and adolescents: a meta-analysis.

OBJECTIVE: This study aimed to systematically review epidemiological evidence on associations between screen time exposure and myopia in children and adolescents, and to quantitatively evaluate summary effect estimates from existing literature. METHOD: There were three online databases including PubMed, Embase, and Web of Science, for epidemiological studies on screen time exposure and myopia published before June 1, 2023. The risk of bias was assessed by the Newcastle Ottawa Scale (NOS) checklist. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the correlation between screen time exposure and myopia using random or fixed-effect models by exposure type (categorical/continuous). We also performed subgroup analysis by screen device type, study quality, geographic region, and research period. RESULTS: We searched 7,571 records from three databases and identified 19 eligible studies, including 14 high-quality studies and 5 moderate-quality studies. Meta-analyses suggested that there was a statistically significant correlation between screen time (high vs. low) and myopia. The pooled ORs with 95%CIs were respectively 2.24 (1.47-3.42) for cross-sectional studies, and 2.39 (2.07-2.76) for cohort studies. We also found a significant association between continuous exposure to screen time (per 1 h/d increase) and myopia in cohort studies. The pooled ORs with 95%CIs were 1.07 (1.01-1.13). In subgroup analysis stratified by screen device type in cross-sectional studies, screen time exposures from computers (categorical: OR = 8.19, 95%CI: 4.78-14.04; continuous: OR = 1.22, 95%CI: 1.10-1.35) and televisions (categorical: OR = 1.46, 95%CI: 1.02-2.10) were associated with myopia, while smartphones were not. Although publication bias was detected, the pooled results did not show significant changes after adjustment using the trim and fill method. CONCLUSION: Our findings support that screen time exposure was significantly associated with myopia in children and adolescents. Notably, screen time exposure from computers may have the most significant impact on myopia.

Influence of eye-related behavior on myopia among junior middle school students under the background of double reduction during the COVID-19 pandemic.

BACKGROUND: To investigate the changes in the unhealthy eye-related behaviors of junior middle school students during the COVID-19 pandemic and the double reduction policy and its relationship with myopia. METHODS: Data were obtained from the 2019-2022 Tianjin Children and Youth Myopia, Common Diseases and Health Influencing Factors Survey. Latent profile analysis (LPA) and a generalized linear model (GLM) were applied to analyze the effect of eye-related behavior classes on myopia. RESULTS: A total of 2508 junior middle school students were included. The types of eye-related behavior were categorized into the medium-healthy behavior group, heavy academic burden and near-eye behavior group, insufficient lighting group and high-healthy behavior group. Students with heavy academic burdens and near-eye behavior were more likely to develop myopia than were those in the high-healthy group (OR = 1.466, 95% CI = 1.203-1.787; P < 0.001). CONCLUSIONS: The dual reduction policy has a positive effect on improving unhealthy eye-related behaviors, and the prevention and control of myopia through the use of different combinations of eye-related behaviors are heterogeneous among junior middle school students. In the post-COVID-19 period, we should continue to implement a double reduction policy and formulate targeted eye-related behavior strategies to provide an important reference for the prevention and control of myopia among children and adolescents during public health emergencies in the future.

The Myopia Prevalence and Association With Physical Activity Among Primary School Students Aged 6-12 Years: A Cross-Sectional Study in Tianjin, China.

Purpose: This study aimed to investigate the prevalence of myopia and determine the association between physical activity and risk of myopia among primary school students in Tianjin, China. Methods: A cross-sectional study was conducted among subjects from nine primary schools. All of the subjects underwent visual acuity and spherical equivalent (SE) with noncycloplegic autorefraction measurement. Myopia was defined as an SE refraction ≤-0.50D and an uncorrected visual acuity <5.0 in either eye. Physical activity was measured via the Physical Activity Questionnaire for Children. Data were analyzed using the Pearson χ2 test and binary logistic regression. Stratification analysis by sex was also performed. Results: A total of 2976 participants (1408 boys and 1568 girls) aged six to 12 years (mean age 8.82 years) were included in this study. The overall prevalence of myopia was 52.92%. When stratified according to physical activity, myopia prevalence significantly decreased with increasing physical activity levels (χ2 trend test = 127.63, P < 0.001). In the binary logistic regression analysis, after adjusting for age, sex, and school region, the odds ratio for the association between physical activity and myopia was 0.762 (95% confidence interval, 0.675-0.862, P < 0.001). When stratified by sex, the significant statistical association between physical activity and myopia both can be found in two groups (P < 0.05). Conclusions: Higher levels of physical activity were independently associated with decreased risk of myopia. The significant reverse statistical association between physical activity and myopia can be found in male or female groups. Translational Relevance: Taking part in physical activities may be an effective way to reduce the prevalence of myopia.

Distribution and prevalence of refractive error in Iranian adult population results of the PERSIAN eye cohort study PECS.

The Persian Eye Cohort Study, a population-based cross-sectional study from 2015 to 2020, examined refractive error prevalence among 48,618 Iranian adults aged 31 to 70. The study encompassed six centers in Iran, employing random cluster sampling for demographic, medical, and socioeconomic data collection through interviews. Ophthalmic exams included visual acuity, automated and manual objective refraction, subjective refraction, slit lamp, and fundus examinations. Using the spherical equivalent definition, the sample population was categorized into groups. Results indicated a mean age of 49.52 ± 9.31 and a mean refractive error of 0.26 diopters (D) ± 1.6 SD (95% CI - 0.27 to -0.24), ranging from -26.1 to + 18.5 SD. Prevalence of myopia (< -0.5D) and hyperopia (> + 0.5D) was 22.6% (95% CI 22.2-23%) and 12.5% (95% CI 12.1-12.8%), respectively. Regarding different age groups, the prevalence of hyperopia and astigmatism exhibited a steady and significant rise with increasing age (p-value < 0.001 for both). The prevalence of Myopia, however, showed a distinctive pattern, initially increasing in adults under 45, declining in those aged 55-64, and rising again among individuals aged 60 and older. Female gender, older age, urban residency, higher education, higher income, and Fars ethnicity were significantly related to a higher prevalence of myopia (p-value < 0.001 for all). Female gender (p-value < 0.001), aging (p-value < 0.001), urban residency (p-value = 0.029), and lower-income (p-value = 0.005) were significantly related to higher prevalence of hyperopia. Astigmatism (> 1D) was prevalent in 25.5% of participants (95% CI 25.1-25.9%) and correlated with male gender, aging, urban residency, illiteracy, and higher income (p-value < 0.001, < 0.001, < 0.001, < 0.001, 0.014, respectively). The study's comparison with regional and international surveys highlighted the increase in myopia among those over 65 due to higher nuclear cataract rates in older adults. Myopia positively related to education, income, and urban residency, while hyperopia did not exhibit such associations.

No Evidence of an Association between Genetic Factors Affecting Response to Vitamin A Supplementation and Myopia: A Mendelian Randomization Study and Meta-Analysis.

The relationship between vitamin A supplementation and myopia has been a topic of debate, with conflicting and inconclusive findings. We aimed to determine whether there is a causal relationship between vitamin A supplementation and the risk of myopia using Mendelian randomization (MR) and meta-analytical methods. Genetic variants from the UK Biobank and FinnGen studies associated with the response to vitamin A supplementation were employed as instrumental variables to evaluate the causal relationship between vitamin A supplementation and myopia. Fixed-effects meta-analysis was then used to combine MR estimates from multiple sources for each outcome. The meta-analysis of MR results found no convincing evidence to support a direct causal relationship between vitamin A supplementation and myopia risk (odds ratio (OR) = 0.99, 95% confidence interval (CI) = 0.82-1.20, I2 = 0%, p = 0.40). The analysis of three out of the four sets of MR analyses indicated no direction of causal effect, whereas the other set of results suggested that higher vitamin A supplementation was associated with a lower risk of myopia (OR = 0.002, 95% CI 1.17 × 10-6-3.099, p = 0.096). This comprehensive MR study and meta-analysis did not find valid evidence of a direct association between vitamin A supplementation and myopia. Vitamin A supplementation may not have an independent effect on myopia, but intraocular processes associated with vitamin A may indirectly contribute to its development.

The gap between parental knowledge and children practice of myopia control and challenge under COVID-19: a web-based survey in China.

Objective: To evaluate parental knowledge of myopia control, investigate its association with children's practice and refractive status, and explore their change under the outbreak of COVID-19 pandemic. Methods: In this web-based survey, a self-administered questionnaire was made online available during the COVID-19 outbreak between February 1th, 2022 and August 31th, 2022 in China. Participants were recruited via social media by convenience and snowball sampling. Parents of both sexes whose children aged between 3 and 18 were eligible. The overall questionnaire was composed of four categories: demographic information, parental knowledge of myopia, children's myopia-related behaviors and their change after the COVID-19 pandemic, and children's refractive status. SPSS version 18.0 was applied to perform the statistics analysis and p < 0.05 was considered to be statistically significant. Results: A total of 423 eligible families were included in our online survey. The average age of children was 11.37 ± 2.83y (male 46.1%; female 53.9%), with a myopia incidence of 83.9% (355/423). Both children's age (OR = -0.6; 95%CI = -1.12 to -0.07; p = 0.026) and family income (OR = 2.60; 95%CI = 1.13 to 4.07; p = 0.001) had independently significant impacts on parental knowledge. Unexpectedly, parental knowledge was negatively correlated with children's onset age of myopia (p = 0.002, r = -0.165) and positively correlated with spectacles wearing (p = 0.014, r = 0.131), and no correlation was found between parental knowledge and the occurrence of children myopia, current diopter, annual myopia progression and the diopter of the first glasses (all p > 0.05). We found discordance phenomenon between parents' knowledge and children's behaviors, with parental knowledge being irrelevant to children's sleeping time (p = 0.159, r = 0.069), the frequency of lying reading (p = 0.462, r = -0.036) and keeping nutrition diet (p = 0.142, r = 0.072), and positively correlated with daily homework time (p = 0.012, r = 0.123). After the outbreak of COVID-19, 77.8% (329/423) of parents admitted that their children's daily routine had been changed, with children spending more time on sleeping (p < 0.001) and electronic products (p < 0.001), and taking less time to do outdoor activities (p < 0.001). Conclusion: The ideal interaction mode that establishing positive impact between parental knowledge and children practice has not been reached in China, which might be the result of insufficient parents' cognition and discordance phenomenon between parental knowledge and children's behaviors. The pandemic of COVID-19 has obviously changed children's daily routine. More efforts should be made to narrow the gap between knowledge and behaviors of myopia control, and stay alert to the potential increased risk of myopia during COVID-19.

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.

Systematic review and meta-analysis of the prevalence of myopia among school-age children in the Eastern Mediterranean Region.

Background: The recent increase in myopia is a major public health concern worldwide, including in the Eastern Mediterranean Region (EMR). Aim: To provide data on the prevalence of myopia among school-age children in the EMR. Methods: This study was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol. We searched the Web of Sciences, Scopus, Index Medicus for the Eastern Mediterranean Region, ProQuest, PubMed, and Medline for studies on the prevalence of myopia in the EMR published from January 2000 to May 2022. The data were analysed using MedCalc version 19.6.1 and myopia was defined as refractive error ≥ 0.50 D. The overall pooled prevalence of myopia was estimated using a random-effects model and its associated 95% confidence intervals. Results: The meta-analysis included 27 quality-assessed studies from 13 countries among 51 111 school-age children. The overall pooled prevalence of childhood myopia from 2000 to 2022 was 5.23%, which was significantly higher among females than males (4.90% vs 3.94%). The prevalence of myopia was significantly higher among children aged 11-17 years than among those aged 5-10 years (7.50% vs 3.90%). There was a higher prevalence of myopia with cycloplegic refraction than noncycloplegic refraction (5.95% vs 3.73%). There was highly significant heterogeneity between the studies. Conclusion: Prevalence of myopia among school-age children in the EMR was high, particularly among older children, and it was more common among females. Early intervention to slow myopia progression is essential in the EMR to protect children from irreversible vision loss.

Light exposure profiles differ between myopes and non-myopes outside school hours.

PURPOSE: Considering the putative role of light in myopia, and variations in socioeconomic, lifestyle, educational and environmental factors across ethnicities, we objectively investigated light exposure patterns in Indian school children. METHODS: The light exposure profile of 143 school children (9-15 years, 50 myopes) recorded using a validated wearable light tracker for six continuous days was analysed. Additional data for non-school days were available for 87 children (26 myopes). The illuminance exposure levels, time spent outdoors and epoch (number of times participant is exposed to a predefined range of lux level per day) were compared between myopes and non-myopes across different light conditions: ≥1000, ≥3000, ≥5000 and ≥10 000 lux. For school days, light exposure profiles during (1) before school, school and after school hours; and (2) class, break and transition (when a student travels to and from school) time were analysed. RESULTS: The overall median (IQR) daily illuminance exposure level, time spent outdoors and epochs at outdoors (≥1000 lux) were 807 (507-1079) lux/day, 46 (30-64) min/day and 9 (6-12) times/day, respectively. The daily illuminance exposure on non-school days was significantly higher in non-myopes than myopes (6369 (4508-9112) vs 5623 (2616-6929) lux/day, p=0.04). During transition time (school days), non-myopes had significantly higher illuminance exposure (910 (388-1479) vs 550 (263-1098) lux/day, p=0.04), spent more time outdoors (25 (10-43) vs 14 (4-29) min/day, p=0.01) and had higher outdoor epochs (6 (4-11) vs 5 (2-8) times/day, p=0.01) than myopes. CONCLUSIONS: A small but significant difference in illuminance exposure, time spent outdoors and epoch was noted between myopes and non-myopes during transition time, which may have implications in myopia control.

Impact of ophthalmic clinical service use in mitigating myopia onset and progression in preschool children: a retrospective cohort study.

BACKGROUND: Although school screenings identify children with vision problems and issue referrals for medical treatment at an ophthalmic hospital, the effectiveness of this approach remains unverified. OBJECTIVE: To investigate the impact of ophthalmic clinical services on the onset and progression of myopia in preschool children identified with vision impairment. METHODS: Using data from the Shanghai Child and Adolescent Large-scale Eye Study (SCALE), this retrospective cohort study evaluated the visual development of children from three districts-Jing'an, Minhang, and Pudong-which are representative of geographic diversity and economic disparity in Shanghai's 17 districts. Initially, in 2015, the study encompassed 14,572 children aged 4-6 years, of whom 5,917 needed a referral. Our cohort consisted of 5,511 children who had two or more vision screenings and complete personal information over the follow-up period from January 2015 to December 2020. We divided these children into two groups based on their initial spherical equivalent (SE): a High-risk group (SE > -0.5 D) and a Myopia group (SE ≤ -0.5 D). Within each of these groups, we further categorized children into Never, Tardily, and Timely groups based on their referral compliance to compare the differences in the occurrence and progression of myopia. Cox proportional models were applied to estimate hazard ratios (HRs) for myopia incidence per person-years of follow-up in High-risk group. Generalized additive models(GAM) was used to calculating the progression for annual spherical equivalent changes in all children. RESULTS: Of the 5,511 preschool children (mean age, 5.25 years; 52.24% male) who received a referral recommendation, 1,327 (24.08%) sought clinical services at an ophthalmic hospital. After six years of follow-up, 65.53% of children developed myopia. The six-year cumulative incidence of myopia in the Never, Tardily, and Timely groups was 64.76%, 69.31%, and 57.14%, respectively. These percentages corresponded to hazard ratios (HRs) of 1.31 (95% CI, 1.10-1.55) for the Tardily group and 0.55 (95% CI, 0.33-0.93) for the Timely group, compared with the Never group. The HRs were adjusted for age, sex, and SE at study entry. Interestingly, the Timely group showed significantly less SE progression than the other groups (P < 0.001), and SE progression was higher in the High-risk group (-0.33 ± 0.37D/year) than in children with myopia (-0.08 ± 0.55D/year). CONCLUSION: Timely utilization of ophthalmic clinical services among children aged 4 to 6 years who fail school vision screenings can significantly reduce the incidence of myopia and slow SE progression.

The knowledge structure and research trends between light and myopia: A bibliometric analysis from 1981 to 2024.

BACKGROUND: This bibliometric analysis explored the knowledge structure of and research trends in the relationship between light and myopia. METHODS: Relevant literature published from 1981 to 2024 was collected from the Web of Science Core Collection database. Visual maps were generated using CiteSpace and VOSviewer. We analyzed the included studies in terms of the annual publication count, countries, institutional affiliations, prolific authors, source journals, top 10 most cited articles, keyword co-occurrence, and cocitations. RESULTS: A total of 525 papers examining the relationship between light and myopia published between 1981 and 2024 were collected. The United States ranked first in terms of the number of publications and actively engaged in international cooperation with other countries. The New England College of Optometry, which is located in the United States, was the most active institution and ranked first in terms of the number of publications. Schaeffel Frank was the most prolific author. The most active journal in the field was Investigative Ophthalmology & Visual Science. The most frequently cited paper in the included studies was written by Saw, SM and was published in 2002. The most common keywords in basic research included "refractive error," "longitudinal chromatic aberration," and "compensation." The most common keywords in clinical research mainly included "light exposure," "school," and "outdoor activity." The current research hotspots in this field are "progression," "refractive development," and "light exposure." The cocitation analysis generated 17 clusters. CONCLUSION: This study is the first to use bibliometric methods to analyze existing research on the relationship between light and myopia. In recent years, the intensity and wavelength of light have become research hotspots in the field. Further research on light of different intensities and wavelengths may provide new perspectives in the future for designing more effective treatments and interventions to reduce the incidence of myopia.