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BACKGROUND: To explore the relationship between outdoor time and academic performance among school-aged children. METHODS: This study was designed as a cross-sectional study. Data were derived from a school-based prospective children myopia intervention study (STORM). Outdoor time was recorded by self-developed algorithm-validated wristwatches in real-time and calculated as the cumulative average of 10 months. The academic performance was recorded and provided by the participating schools and further standardized. Other information was collected using an online standardized questionnaire. Mixed-effects model and B-Spline method were used to investigate the association between time spent on different types of daily activity, including outdoor activity and academic performance. RESULTS: A total of 3291 children with mean age 9.25 years were included in the final analysis. Overall, outdoor time was associated with academic performance in a non-linear manner; specifically, not exceeding 2.3 h per day, outdoor time was positively associated with academic performance; exceeding 2.3 h per day, this association became non-significant. Likewise, daily sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner, resulting in turning points of 11.3 and 1.4 h per day, respectively. Separate analysis showed that outdoor time and sleep duration but not out-of-school learning time were positively associated with academic performance in Chinese, mathematics and English. CONCLUSION: Outdoor time, sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner. Promotion of outdoor time may not negatively impact on academic performance. TRIAL REGISTRATION: Our study was registered in ClinicalTrials.gov (Identifier: NCT02980445).

BACKGROUND: Informed decisions on myopia management require an understanding of financial impact. We describe methodology for estimating lifetime myopia costs, with comparison across management options, using exemplars in Australia and China. METHODS: We demonstrate a process for modelling lifetime costs of traditional myopia management (TMM=full, single-vision correction) and active myopia management (AMM) options with clinically meaningful treatment efficacy. Evidence-based, location-specific and ethnicity-specific progression data determined the likelihood of all possible refractive outcomes. Myopia care costs were collected from published sources and key informants. Refractive and ocular health decisions were based on standard clinical protocols that responded to the speed of progression, level of myopia, and associated risks of pathology and vision impairment. We used the progressions, costs, protocols and risks to estimate and compare lifetime cost of myopia under each scenario and tested the effect of 0%, 3% and 5% annual discounting, where discounting adjusts future costs to 2020 value. RESULTS: Low-dose atropine, antimyopia spectacles, antimyopia multifocal soft contact lenses and orthokeratology met our AMM inclusion criteria. Lifetime cost for TMM with 3% discounting was US$7437 (CI US$4953 to US$10 740) in Australia and US$8006 (CI US$3026 to US$13 707) in China. The lowest lifetime cost options with 3% discounting were antimyopia spectacles (US$7280, CI US$5246 to US$9888) in Australia and low-dose atropine (US$4453, CI US$2136 to US$9115) in China. CONCLUSIONS: Financial investment in AMM during childhood may be balanced or exceeded across a lifetime by reduced refractive progression, simpler lenses, and reduced risk of pathology and vision loss. Our methodology can be applied to estimate cost in comparable scenarios.

PURPOSE: To evaluate the efficacy of time outdoors per school day over 2 years on myopia onset and shift. DESIGN: A prospective, cluster-randomized, examiner-masked, 3-arm trial. PARTICIPANTS: A total of 6295 students aged 6 to 9 years from 24 primary schools in Shanghai, China, stratified and randomized by school in a 1:1:1 ratio to control (n = 2037), test I (n = 2329), or test II (n = 1929) group. METHODS: An additional 40 or 80 minutes of outdoor time was allocated to each school day for test I and II groups. Children in the control group continued their habitual outdoor time. Objective monitoring of outdoor and indoor time and light intensity each day was measured with a wrist-worn wearable during the second-year follow-up. MAIN OUTCOME MEASURES: The 2-year cumulative incidence of myopia (defined as cycloplegic spherical equivalent [SE] of ≤-0.5 diopters [D] in the right eye) among the students without myopia at baseline and changes in SE and axial length (AL) after 2 years. RESULTS: The unadjusted 2-year cumulative incidence of myopia was 24.9%, 20.6%, and 23.8% for control, test I, and II groups, respectively. The adjusted incidence decreased by 16% (incidence risk ratio [IRR], 0.84; 95% confidence interval [CI], 0.72-0.99; P = 0.035) in test I and 11% (IRR = 0.89; 95% CI, 0.79-0.99; P = 0.041) in test II when compared with the control group. The test groups showed less myopic shift and axial elongation compared with the control group (test I: -0.84 D and 0.55 mm, test II: -0.91 D and 0.57 mm, control: -1.04 D and 0.65 mm). There was no significant difference in the adjusted incidence of myopia and myopic shift between the 2 test groups. The test groups had similar outdoor time and light intensity (test I: 127 ± 30 minutes/day and 3557 ± 970 lux/minute; test II: 127 ± 26 minutes/day and 3662 ± 803 lux/minute) but significantly more outdoor time and higher light intensity compared with the control group (106 ± 27 minutes/day and 2984 ± 806 lux/minute). Daily o

Item does not contain fulltext, PURPOSE: The International Myopia Institute (IMI) Yearly Digest highlights new research considered to be of importance since the publication of the first series of IMI white papers. METHODS: A literature search was conducted for articles on myopia between 2019 and mid-2020 to inform definitions and classifications, experimental models, genetics, interventions, clinical trials, and clinical management. Conference abstracts from key meetings in the same period were also considered. RESULTS: One thousand articles on myopia have been published between 2019 and mid-2020. Key advances include the use of the definition of premyopia in studies currently under way to test interventions in myopia, new definitions in the field of pathologic myopia, the role of new pharmacologic treatments in experimental models such as intraocular pressure-lowering latanoprost, a large meta-analysis of refractive error identifying 336 new genetic loci, new clinical interventions such as the defocus incorporated multisegment spectacles and combination therapy with low-dose atropine and orthokeratology (OK), normative standards in refractive error, the ethical dilemma of a placebo control group when myopia control treatments are established, reporting the physical metric of myopia reduction versus a percentage reduction, comparison of the risk of pediatric OK wear with risk of vision impairment in myopia, the justification of preventing myopic and axial length increase versus quality of life, and future vision loss. CONCLUSIONS: Large amounts of research in myopia have been published since the IMI 2019 white papers were released. The yearly digest serves to highlight the latest research and advances in myopia.

PURPOSE: The International Myopia Institute (IMI) Yearly Digest highlights new research considered to be of importance since the publication of the first series of IMI white papers. METHODS: A literature search was conducted for articles on myopia between 2019 and mid-2020 to inform definitions and classifications, experimental models, genetics, interventions, clinical trials, and clinical management. Conference abstracts from key meetings in the same period were also considered. RESULTS: One thousand articles on myopia have been published between 2019 and mid-2020. Key advances include the use of the definition of premyopia in studies currently under way to test interventions in myopia, new definitions in the field of pathologic myopia, the role of new pharmacologic treatments in experimental models such as intraocular pressure-lowering latanoprost, a large meta-analysis of refractive error identifying 336 new genetic loci, new clinical interventions such as the defocus incorporated multisegment spectacles and combination therapy with low-dose atropine and orthokeratology (OK), normative standards in refractive error, the ethical dilemma of a placebo control group when myopia control treatments are established, reporting the physical metric of myopia reduction versus a percentage reduction, comparison of the risk of pediatric OK wear with risk of vision impairment in myopia, the justification of preventing myopic and axial length increase versus quality of life, and future vision loss. CONCLUSIONS: Large amounts of research in myopia have been published since the IMI 2019 white papers were released. The yearly digest serves to highlight the latest research and advances in myopia.

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

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

Risk factor analysis provides an important basis for developing interventions for any condition. In the case of myopia, evidence for a large number of risk factors has been presented, but they have not been systematically tested for confounding. To be useful for designing preventive interventions, risk factor analysis ideally needs to be carried through to demonstration of a causal connection, with a defined mechanism. Statistical analysis is often complicated by covariation of variables, and demonstration of a causal relationship between a factor and myopia using Mendelian randomization or in a randomized clinical trial should be aimed for. When strict analysis of this kind is applied, associations between various measures of educational pressure and myopia are consistently observed. However, associations between more nearwork and more myopia are generally weak and inconsistent, but have been supported by meta-analysis. Associations between time outdoors and less myopia are stronger and more consistently observed, including by meta-analysis. Measurement of nearwork and time outdoors has traditionally been performed with questionnaires, but is increasingly being pursued with wearable objective devices. A causal link between increased years of education and more myopia has been confirmed by Mendelian randomization, whereas the protective effect of increased time outdoors from the development of myopia has been confirmed in randomized clinical trials. Other proposed risk factors need to be tested to see if they modulate these variables. The evidence linking increased screen time to myopia is weak and inconsistent, although limitations on screen time are increasingly under consideration as interventions to control the epidemic of myopia.

PURPOSE: To examine 2-year progression rate and associated biometric changes in highly myopic eyes. METHODS: This is a longitudinal, observational cohort study that included 657 participants aged 7 to 70 years with bilateral high myopia (≤-6.00 diopters [D]) and followed for 2 years. All participants underwent ocular biometry and cycloplegic refraction examinations. Main outcome measures were changes in spherical equivalent refraction (SE) and ocular biometry in the right eyes. RESULTS: Mean age of participants was 21.6 ± 12.2 years. At baseline, mean SE was -9.82 ± 3.28 D and ocular biometric measurements were 27.40 ± 1.56 mm for axial length, 3.16 ± 0.27 mm for anterior chamber depth, 3.60 ± 0.35 mm for lens thickness, and 20.09 ± 1.50 mm for vitreous chamber depth. After 2 years of follow-up, there was a trend toward more myopia and greater axial elongation in all age groups. Younger participants (≤20 years) had significantly (P < 0.001) greater rates of myopic shift and axial elongation compared with older participants (>20 years). However, highly myopic adults aged 40 to 70 years continued to demonstrate refractive progression, particularly if they had extremely high myopia (≤-10.00 D). In the multiple regression analysis, each additional diopter of myopia at baseline was associated with a 11% higher risk of a >1.00-D/y myopic shift (odds ratio, 1.11; 95% confidence interval, 1.04-1.18; P = 0.002). CONCLUSIONS: Longitudinal data from this large Chinese cohort suggest that highly myopic eyes continue to progress in SE throughout life, with the greatest rates of progression observed in younger participants. Axial elongation rates appeared to stabilize after 20 years of age and were predominantly due to an increase in the vitreous chamber depth. Other risk factors for a myopic shift included a higher degree of myopic refraction at baseline.

Importance Understanding visual impairment (VI) under different definitions and potential risk factors in high myopic is important for future myopia control. Background Limited studies exists investigating the VI among high myopic and with varying VI definitions. Design Registry cohort study. Participants Eight hundred and eighty‐four participants were from ZOC‐BHVI study. Methods Subjects aged 7 to 70 years with high myopia were enrolled. Uncorrected visual acuity and best‐corrected visual acuity (UCVA and BCVA), cycloplegic refraction, axial length (AL), corneal curvatures, anterior chamber depth and lens thickness were measured. Axial length/corneal radius of curvature ratio (AL/CR ratio) was calculated. Fundus lesions were graded into five categories. VI and blindness were defined based on the better‐seeing eye according to the World Health Organization (WHO) criteria and US criteria. Multiple logistic regression analysis was used to assess risk factors for VI. Main Outcome Measures Rates of VI and blindness. Results A total of 884 participants were included, with mean (SD) age 18.5 (12.4) years and 46.4% male. Rate of UCVI/blindness were 72.6%/27.3% and 17.9%/82.1% based on WHO and US criteria. With respect to BCVA, 4.1%/5.9% of participants had BCVI using two definitions, whereas the rate for blindness was 0.2% and 0.6%. After adjusting confounders, multiple logistic regression showed that more severe fundus lesions, greater AL/CR ratio were at a higher risk of being VI, both in two definitions (P < .005). Conclusions and Relevance The rate of VI and blindness in highly myopic patients varies significantly using different definition. Severe fundus lesions and greater AL/CR ratios were associated with a higher risk of VI.

© 2019 The Authors. Best practice clinical guidelines for myopia control involve an understanding of the epidemiology of myopia, risk factors, visual environment interventions, and optical and pharmacologic treatments, as well as skills to translate the risks and benefits of a given myopia control treatment into lay language for both the patient and their parent or caregiver. This report details evidence-based best practice management of the pre-, stable, and the progressing myope, including risk factor identification, examination, selection of treatment strategies, and guidelines for ongoing management. Practitioner considerations such as informed consent, prescribing off-label treatment, and guides for patient and parent communication are detailed. The future research directions of myopia interventions and treatments are discussed, along with the provision of clinical references, resources, and recommendations for continuing professional education in this growing area of clinical practice.

Purpose We used systematic review and meta-analysis to identify and assimilate evidence quantifying blindness and visual impairment (VI) associated with myopic macular degeneration (MMD), then derived models to predict global patterns. The models were used to estimate the global prevalence of blindness and VI associated with MMD from 2000 to 2050. Methods The systematic review identified 17 papers with prevalence data for MMD VI fitting our inclusion criteria. Data from six papers with age-specific data were scaled to relative age-dependent risk and meta-analysed at VI and blindness levels. We analysed variance in all MMD VI and blindness data as a proportion of high myopia against variables from the place and year of data collection, with a model based on health expenditure providing the best correlation. We used this model to estimate the prevalence and number of people with MMD VI in each country in each decade. Results We included data from 17 studies comprising 137 514 participants. We estimated 10.0 million people had VI from MMD in 2015 (prevalence 0.13%, 95% CI 5.5 to 23.7 million, 0.07% to 0.34%), 3.3 million of whom were blind (0.04%, 1.8 to 7.8 million, 0.03% to 0.10%). We estimate that by 2050, without changing current interventions, VI from MMD will grow to 55.7 million people (0.57%, 29.0 to 119.7 million, 0.33% to 1.11%), 18.5 million of whom will be blind (0.19%, 9.6 to 39.7 million, 0.11% to 0.37%). Conclusion The burden of MMD blindness and VI will rise significantly without efforts to reduce the development and progression of myopia and improve the management of MMD.

Purpose: To systematically analyse the differences between cycloplegic and noncycloplegic refractive errors (RE) in children and to determine if the predictive value of noncycloplegic RE in categorizing RE can be improved. Methods: Random cluster sampling was used to select 6825 children aged 4–15 years. Autorefraction was performed under both noncycloplegic and cycloplegic (induced with 1% cyclopentolate drops) conditions. Paired differences between noncycloplegic and cycloplegic spherical equivalent (SE) RE were determined. A general linear model was developed to determine whether cycloplegic SE can be predicted using noncycloplegic SE, age and uncorrected visual acuity (UCVA). Results: Compared to cycloplegia, noncycloplegia resulted in a more myopic SE (paired difference: −0.63 ± 0.65D, 95% CI: −0.612 to −0.65D, 6017 eligible right eyes) with greater differences observed in younger participants and in eyes with more hyperopic RE and smaller AL. Using raw noncycloplegic data resulted in only 61% of the eyes being correctly classified as myopic, emmetropic or hyperopic. Using age and uncorrected VA in the model, the association improved and 77% of the eyes were classified correctly. However, predicted cycloplegic SE continued to show large residual errors for low myopic to hyperopic RE. Applying the model to only those eyes with uncorrected VA <6/6 resulted in an improvement (R2= 0. 93), with 80% of the eyes correctly classified. A higher VA cut-off (i.e., ≤6/18) resulted in 97.5% of eyes classified correctly. Conclusion: Noncycloplegic assessment of RE in children overestimates myopia and results in a high error rate for emmetropic and hyperopic RE. Adjusting for age and applying uncorrected VA cut-offs to noncycloplegic assessments improves detection of myopic RE and may help in identifying myopic RE in situations where cycloplegia is not available but does not help in identifying the magnitude of refractive error and therefore is of limited value.