Outdoor activity during class recess reduces myopia onset and progression in school children

The Evolution and the Impact of Refractive Errors on Academic Performance: A Pilot Study of Portuguese School-Aged Children

The relationship between vision and academic performance has been discussed for a long time, with special emphasis on visual factors associated with learning problems. The objective of this pilot study is to obtain an initial idea about the evolution and the impact of refractive errors on school-aged children. A visual examination was performed on 252 children between the ages of 6 and 11 years, which consisted of objective refraction, subjective refraction, and accommodative and binocular tests. No significant differences were observed regarding the refractive state when taking academic performance into account (p > 0.05). However, it was determined that academic performance was better among children with a negative spherical equivalent. Studies with a larger sample size must be conducted to verify the results that were attained in this present pilot study, and these must likewise look at possible ways in which strategies can be implemented in schools to reduce myopia progression.

Candidate pathways for retina to scleral signaling in refractive eye growth

The global prevalence of myopia, or nearsightedness, has increased at an alarming rate over the last few decades. An eye is myopic if incoming light focuses prior to reaching the retinal photoreceptors, which indicates a mismatch in its shape and optical power. This mismatch commonly results from excessive axial elongation. Important drivers of the myopia epidemic include environmental factors, genetic factors, and their interactions, e.g., genetic factors influencing the effects of environmental factors. One factor often hypothesized to be a driver of the myopia epidemic is environmental light, which has changed drastically and rapidly on a global scale. In support of this, it is well established that eye size is regulated by a homeostatic process that incorporates visual cues (emmetropization). This process allows the eye to detect and minimize refractive errors quite accurately and locally over time by modulating the rate of elongation of the eye via remodeling its outermost coat, the sclera. Critically, emmetropization is not dependent on post-retinal processing. Thus, visual cues appear to influence axial elongation through a retina-to-sclera, or retinoscleral, signaling cascade, capable of transmitting information from the innermost layer of the eye to the outermost layer. Despite significant global research interest, the specifics of retinoscleral signaling pathways remain elusive. While a few pharmacological treatments have proven to be effective in slowing axial elongation (most notably topical atropine), the mechanisms behind these treatments are still not fully understood. Additionally, several retinal neuromodulators, neurotransmitters, and other small molecules have been found to influence axial length and/or refractive error or be influenced by myopigenic cues, yet little progress has been made explaining how the signal that originates in the retina crosses the highly vascular choroid to affect the sclera. Here, we compile and synthesize the evidence surrounding three of the major candidate pathways receiving significant research attention - dopamine, retinoic acid, and adenosine. All three candidates have both correlational and causal evidence backing their involvement in axial elongation and have been implicated by multiple independent research groups across diverse species. Two hypothesized mechanisms are presented for how a retina-originating signal crosses the choroid - via 1) all-trans retinoic acid or 2) choroidal blood flow influencing scleral oxygenation. Evidence of crosstalk between the pathways is discussed in the context of these two mechanisms.

Sports and Myopia: An Investigation on the Prevalence and Risk Factors of Myopia in Young Sports-Related Groups in Tianjin, China

Objective

To explore the relationship between sports and the prevalence of myopia in young sports-related groups in Tianjin, China.

Methods

In this cross-sectional study, a cluster sampling method was used to survey professional athletes in Tianjin, students at Tianjin University of Sport, and Tianjin Vocational College of Sports. All participants completed epidemiological questionnaires and ophthalmic examinations. Multivariable logistic regression models were used to explore the potential risk factors of myopia.

Results

This study recruited 1401 participants. The prevalence of myopia was 50.18%. The prevalence of low, moderate, and high myopia were 52.63%, 37.41%, and 9.96%, respectively. There were no sex-related differences in the prevalence of myopia. The odds of having myopia was 1.788 times higher in the indoor sports group than the outdoor sports group (the adjusted odds ratio [OR], 95% confidence interval [CI], 1.391–2.297). Training time of more than 4 h/d (4–6 h/d: OR, 0.539; 95% CI, 0.310–0.938; >6 h/d: OR, 0.466; 95% CI, 0.257–0.844) resulted in a lower risk of myopia. Participants who often used the electronic screen (OR, 1.406; 95% CI, 1.028–1.923) and/or had a family history of myopia (OR, 2.022; 95% CI, 1.480–2.763) were more likely to suffer from myopia.

Conclusions

Outdoor sports do not necessarily guarantee to insulate against myopia. Youngsters engaged in outdoor sports had a lower prevalence of myopia than those participating in indoor sports. Electronic screen use, training time, and family history of myopia were also associated with the prevalence of myopia in young sports-related groups.

A systematic review of near work and myopia: measurement, relationships, mechanisms and clinical corollaries

After decades of investigation, the role of near work in myopia remains unresolved, with some studies reporting no relationship and others finding the opposite. This systematic review is intended to summarize classic and recent literature investigating near work and the onset and progression of myopia, potential mechanisms and pertinent clinical recommendations. The impact of electronic device use is considered. PubMed and Medline were used to find peer-reviewed cross-sectional and longitudinal studies related to near work and myopia from 1980 to July 2020 using the PRISMA checklist. Studies were chosen using the Joanna Briggs Institute checklist, with a focus on studies with a sample size greater than 50. Studies were independently evaluated; conclusions were drawn per these evaluations. Numerous cross-sectional studies found increased odds ratio of myopia with increased near work. While early longitudinal studies failed to find this relationship, more recent longitudinal studies have found a relationship between myopia and near work. Rather than daily duration of near work, interest has increased regarding absolute working distance and duration of continuous near viewing. Several reports have found that shorter working distances (<30 cm) and continuous near-work activity (>30 min) are risk factors for myopia onset and progression. Novel objective continuously measuring rangefinding devices have been developed to better address these questions. The literature is conflicting, likely due to the subjective and variable nature in which near work has been quantified and a paucity of longitudinal studies. We conclude that more precise objective measures of near viewing behaviour are necessary to make definitive conclusions regarding the relationship between myopia and near work. Focus should shift to utilizing objective and continuously measuring instruments to quantify near-work behaviours in children, followed longitudinally, to understand the complex factors related to near work. A better understanding of the roles of absolute working distance, temporal properties, viewing breaks and electronic device use on myopia development and progression will aid in the development of evidence-based clinical recommendations for behavioural modifications to prevent and slow myopia.

Lipidomic analysis revealed n-3 polyunsaturated fatty acids suppressed choroidal thinning and myopia progression in mice

Myopia is increasing worldwide and its preventable measure should urgently be pursued. N-3 polyunsaturated fatty acids (PUFAs) have been reported to have various effects such as vasodilative and anti-inflammatory, which myopia may be involved in. This study is to investigate the inhibitory effect of PUFAs on myopia progression. A lens-induced myopia (LIM) model was prepared using C57B L6/J 3-week-old mice, which were equipped with a -30 diopter lens to the right eye. Chows containing two different ratios of n-3/n-6 PUFA were administered to the mice, and myopic shifts were confirmed in choroidal thickness, refraction, and axial length in the n-3 PUFA-enriched chow group after 5 weeks. To exclude the possibility that the other ingredients in the chow may have taken the suppressive effect, fat-1 transgenic mice, which can produce n-3 PUFAs endogenously, demonstrated significant suppression of myopia. To identify what elements in n-3 PUFAs took effects on myopia suppression, enucleated eyes were used for targeted lipidomic analysis, and eicosapentaenoic acid (EPA) were characteristically distributed. Administration of EPA to the LIM model confirmed the inhibitory effect on choroidal thinning and myopia progression. Subsequently, to identify the elements and the metabolites of fatty acids effective on myopia suppression, targeted lipidomic analysis was performed and it demonstrated that metabolites of EPA were involved in myopia suppression, whereas prostaglandin E2 and 14,15-dihydrotestosterone were associated with progression of myopia. In conclusion, EPA and its metabolites are related to myopia suppression and inhibition of choroidal thinning.

Efficacy of 0.01% low dose atropine and its correlation with various factors in myopia control in the Indian population

We aimed to evaluate the efficacy and safety of low-dose atropine compared to placebo in the Indian population and also to study the impact of various modifiable and non-modifiable factors on myopia progression (MP) and drug efficacy (DE). It was a single-centre prospective placebo-controlled interventional study. 43 participants aged 6–16 years with progressive myopia received 0.01% atropine in the right eyes (treatment) and placebo in the left eyes (control) for 1-year. The main outcome measures were annual MP and axial length elongation (ALE) in treatment and control eyes and their percentage difference between two eyes (drug efficacy). Secondary outcome measures were the occurrence of any adverse events and the correlation of MP, ALE, and DE with various factors. 40 participants (80 eyes) completed the follow-up. After 1-year, MP was 0.25 D (IQR 0.13–0.44) and 0.69 D (IQR 0.50–1.0) (p < 0.001) in treatment and control respectively (63.89% reduction) with respective ALE of 0.14 mm (IQR 0.05–0.35) and 0.32 mm (IQR 0.19–0.46) (p < 0.001) (44.44% reduction). No adverse events were noted. Reduction in MP and ALE was statistically significant in all children irrespective of age-group, baseline MP, family history, screen-time, near and outdoor-time. The strongest determinants of annual MP were age (Treatment: r = − 0.418, p = 0.007; Control: r = − 0.452, p = 0.003) and baseline MP (Treatment: r = 0.64, p = 0.000; Control: r = 0.79, p = 0.000). Screen-time in control eyes was associated with greater ALE (r = 0.620, p = 0.042). DE was higher when outdoor time exceeded 2 h/day (p = 0.035) while the efficacy was lower with prolonged near activities (p = 0.03), baseline fast-progressors (p < 0.05) and history of parental myopia (p < 0.05). 0.01% atropine is effective and safe in retarding MP and ALE in Indian eyes.

Time spent outdoors as an intervention for myopia prevention and control in children: an overview of systematic reviews

PURPOSE

Outdoor light exposure is considered a safe and effective strategy to reduce myopia development and aligns with existing public health initiatives to promote healthier lifestyles in children. However, it is unclear whether this strategy reduces myopia progression in eyes that are already myopic. This study aims to conduct an overview of systematic reviews (SRs) reporting time spent outdoors as a strategy to prevent myopia or slow its progression in children.

METHODS

We searched the Cochrane Library, EMBASE, MEDLINE and CINAHL from inception to 1 November 2020 to identify SRs that evaluated the association between outdoor light exposure and myopia development or progression in children. Outcomes included incident myopia, prevalent myopia and change in spherical equivalent refraction (SER) and axial length (AL) to evaluate annual rates of myopia progression. The methodological quality and risk of bias of included SRs were assessed using the AMSTAR-2 and ROBIS tools, respectively.

RESULTS

Seven SRs were identified, which included data from 47 primary studies with 63,920 participants. Pooled estimates (risk or odds ratios) consistently demonstrated that time outdoors was associated with a reduction in prevalence and incidence of myopia. In terms of slowing progression in eyes that were already myopic, the reported annual reductions in SER and AL from baseline were small (0.13-0.17 D) and regarded as clinically insignificant. Methodological quality assessment using AMSTAR-2 found that all reviews had one or more critical flaws and the ROBIS tool identified a low risk of bias in only two of the included SRs.

CONCLUSION

This overview found that increased exposure to outdoor light reduces myopia development. However, based on annual change in SER and AL, there is insufficient evidence for a clinically significant effect on myopia progression. The poor methodological quality and inconsistent reporting of the included systematic reviews reduce confidence in the estimates of effect.

Near work, screen time, outdoor time and myopia in schoolchildren in the Sunflower Myopia AEEC Consortium

PURPOSE

To examine the association between near work, screen time including TV and outdoor time with myopia in children from the Sunflower Myopia Asian Eye Epidemiology Consortium (AEEC).

METHODS

We analysed AEEC cross-sectional data (12 241 children) on risk factors (near work, screen time including TV and outdoor time) and myopia of six population-based studies (China, Hong Kong and Singapore). Cycloplegic refraction and axial length (AL) measurements were included. Risk factors were determined using questionnaires. Data were pooled from each study, and multivariable regression analysis was performed to evaluate the associations between risks factors and myopia, spherical equivalent (SE) and AL.

RESULTS

Among the included children, 52.1% were boys, 98.1% were Chinese and 69.7% lived in urban areas. Mean±standard deviation (SD) for age was 8.8 ± 2.9 years, for SE was -0.14 ± 1.8 D and for AL was 23.3 ± 1.1 mm. Myopia prevalence was 30.6%. In multivariate analysis, more reading and writing (OR = 1.17; 95% CI, 1.11-1.24), more total near work (OR = 1.05; 95% CI, 1.02-1.09) and less outdoor time (OR = 0.82, 95% CI, 0.75-0.88) were associated with myopia (p's < 0.05). These factors were similarly associated with SE and AL (p's < 0.05), except for total near work and AL (p = 0.15). Screen time including TV was not significantly associated with myopia (p = 0.49), SE (p = 0.49) or AL (p = 0.83).

CONCLUSION

In this study, increased reading and writing and decreased outdoor time were associated with myopia. Screen time may be a surrogate factor of near work or outdoor time, but further research is needed to assess its role as an independent risk factor for myopia.

Mutation survey in Taiwanese patients with Stickler syndrome

PURPOSE

The purpose of this study was to identify gene mutation and phenotype correlations in a cohort of Taiwanese patients with Stickler syndrome.

MATERIALS AND METHODS

Patients clinically diagnosed with Stickler syndrome or suspected Stickler syndrome were enrolled. DNA was extracted from venous blood samples. For the targeted next-generation sequencing (NGS) approach, specific primers were designed for all COL2A1, COL11A1, COL11A2, COL9A1, and COL9A2 exons and flanking intron sequences.

RESULTS

Twenty-three patients from 12 families were enrolled in this study. The myopia power in these 23 cases (35 eyes) ranged from -4.625 to -25.625 D, with a median of -10.00 D. Four patients had retinal detachment. Fourteen patients had a cleft palate. These 23 patients and 13 healthy controls were enrolled in the NGS study. Three families had significant single nucleotide variants (SNVs) in COL2A1. The mutation rates in this survey were 25% (3/12 families) and 35% (8/23 cases). The SNV of family #1, located at exon 27, c.1753G >T, p. Gly585Val, was novel and has not yet been reported in the ClinVar database. Families #10 and #11 had the same SNV, located in exon 33, c.2101C >T, p. Arg701X. Both variants were classified as likely pathogenic according to the American College of Medical Genetics and Genomics guidelines.

CONCLUSION

Genetic mutations in COL2A1 were found in 25% of Taiwanese families with Stickler syndrome. One novel variant was identified using NGS, which expanded the COL2A1 mutation spectrum. Molecular genetic analysis is helpful to confirm the clinical diagnosis of patients with suspected Stickler syndrome.

Simulations to Assess the Performance of Multifactor Risk Scores for Predicting Myopia Prevalence in Children and Adolescents in China

Background: Myopia is the most common visual impairment among Chinese children and adolescents. The purpose of this study is to explore key interventions for myopia prevalence, especially for early-onset myopia and high myopia.

Methods: Univariate and multivariate analyses were conducted to evaluate potential associations between risk factor exposure and myopia. LASSO was performed to prioritize the risk features, and the selected leading factors were used to establish the assembled simulation model. Finally, two forecasting models were constructed to predict the risk of myopia and high myopia.

Results: Children and adolescents with persistently incorrect posture had a high risk of myopia (OR 7.205, 95% CI 5.999–8.652), which was 2.8 times higher than that in students who always maintained correct posture. In the cohort with high myopia, sleep time of less than 7 h per day (OR 9.789, 95% CI 6.865–13.958), incorrect sitting posture (OR 8.975, 95% CI 5.339–15.086), and siblings with spherical equivalent &lt;−6.00 D (OR 8.439, 95% CI 5.420–13.142) were the top three risk factors. The AUCs of integrated simulation models for myopia and high myopia were 0.8716 and 0.8191, respectively.

Conclusion: The findings illustrate that keeping incorrect posture is the leading risk factor for myopia onset, while the onset age of myopia is the primary factor affecting high myopia progression. The age between 8 and 12 years is the crucial stage for clinical intervention, especially for children with parental myopia.

Sleep Patterns and Myopia Among School-Aged Children in Singapore

Purpose

To evaluate the associations of sleep factors with myopia, spherical equivalent (SE), and axial length (AL) in elementary school-aged children from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort.

Methods

This cross-sectional study included multi-ethnic children who participated in the GUSTO prospective birth cohort and were delivered in two major tertiary hospitals in Singapore (2009–2010). Sleep factors and myopia outcomes were assessed at the 8- and 9-year study visits, respectively. Parent-reported sleep quality was assessed with the Children's Sleep Habits Questionnaire (CSHQ) total scores. Additionally, each child's sleep duration, timing (bedtime; waketime), and the consistency of sleep duration or timing (i.e., the difference between weekends and weekdays) were parent-reported. Outcomes included cycloplegic SE, myopia (SE ≤ −0.5 D) and AL. Eye measurements from both eyes were included in the analyses. Multivariable linear or logistic regression with Generalized Estimating Equations were used to account for the correlation between paired eyes and confounders in the associations of sleep factors at age 8 and myopia at age 9.

Results

A total of 572 multi-ethnic children (49.5% boys; 56.1% Chinese) aged 9 years were included in the analyses. Overall, 37.3% of eyes were myopic. Children reported a mean total CSHQ score of 46 [standard deviation (SD) = 6]. The mean duration of sleep was 9.2 (SD = 1.0) hours per day (h/day), with 59.9% of children reporting sufficient sleep (≥9 h/day) based on guidelines recommended by the National Sleep Foundation, USA. The mean bedtime and wake time were 22:00 (SD = 00:53) and 07:08 (SD = 00:55), respectively. In multivariable regression models, total CSHQ scores, the duration of sleep, bedtime and wake time were not significantly associated with myopia, SE, or AL (p ≥ 0.05 for all), adjusting for gender, ethnicity, time outdoors, near-work, parental myopia, maternal education levels (and additionally the child's height when the outcome was AL). Similarly, the consistency of both the duration and timing of sleep (across weekends and weekdays) were not significantly associated with myopia, SE, or AL (p ≥ 0.05 for all).

Conclusion

In this cross-sectional study, sleep quality, duration, timing, and the consistency of specific sleep factors were not independently associated with myopia, SE, or AL among elementary school-aged children in Singapore. Large longitudinal studies are warranted to corroborate these results.

Light Signaling and Myopia Development: A Review

INTRODUCTION

The aim of this article was to comprehensively review the relationship between light exposure and myopia with a focus on the effects of the light wavelength, illuminance, and contrast on the occurrence and progression of myopia.

METHODS

This review was performed by searching PubMed data sets including research articles and reviews utilizing the terms "light", "myopia", "refractive error", and "illuminance", and the review was concluded in November 2021. Myopia onset and progression were closely linked with emmetropization and hyperopia. To better elucidate the mechanism of myopia, some of the articles that focused on this topic were included. This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.

RESULTS

The pathogenesis and prevention of myopia are not completely clear. Studies have provided evidence supporting the idea that light could affect eye growth in three ways. Changing the corresponding conditions will cause changes in the growth rate and mode of the eyes, and preliminary results have shown that FR/NIR (far red/near-infrared) light is effective for myopia in juveniles.

CONCLUSION

This review discusses the results of studies on the effects of light exposure on myopia with the aims of providing clues and a theoretical basis for the use of light to control the development of myopia and offering new ideas for subsequent studies.

The Changes in Visual Acuity Values of Japanese School Children during the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) pandemic may result in a greater decrease in visual acuity (VA) among Japanese children. Our study aimed to examine Japanese children’s VA during the pandemic. VA data were collected using standard eye tests during school health check-ups conducted in 2019 and 2020 on 5893 children, in seven public elementary schools and four public junior high schools in Tokyo, Saitama, Kanagawa, and Shizuoka. VA changes were statistically analyzed. The relationship between the survey year and poor VA yielded a significant regression coefficient for the surveyed years in elementary and junior high school students. The 2019 VA value and VA change from 2019 to 2020 demonstrated a significant regression coefficient in elementary school students with VAs of “B (0.7−0.9)” and “C (0.3−0.6)”, and junior high school students with VAs of “B”, “C”, and “D (<0.3)”. An analysis of the relationship between the survey year and eye laterality of VA yielded a significant regression coefficient in the surveyed years for elementary (OR, 1.516; 95% CI, 1.265−1.818) and junior high school students (OR, 1.423; 95% CI, 1.136−1.782). Lifestyle changes during the COVID-19 pandemic might have affected VA and eye laterality in Japanese children.

Physical activity, time spent outdoors, and near work in relation to myopia prevalence, incidence, and progression: An overview of systematic reviews and meta-analyses

Myopia has reached epidemic levels in recent years. Stopping the development and progression of myopia is critical, as high myopia is a major cause of blindness worldwide. This overview aims at finding the association of time spent outdoors (TSO), near work (NW), and physical activity (PA) with the incidence, prevalence, and progression of myopia in children. Literature search was conducted in PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Database of Systematic Reviews, ProQuest, and Web of Science databases. Systematic reviews (SR) and meta-analyses (MA) on the TSO, NW, and PA in relation to myopia were reviewed. Methodological nature of qualified studies were evaluated utilizing the Risk of Bias in Systematic Review tool. We identified four SRs out of which three had MA, which included 62 unique studies, involving >1,00,000 children. This overview found a protective trend toward TSO with a pooled odds ratio (OR) of 0.982 (95% confidence interval (CI) 0.979-0.985, I2 = 93.5%, P < 0.001) per extra hour of TSO every week. A pooled OR 1.14 (95% CI 1.08-1.20) suggested NW to be related to risk of myopia. However, studies associating myopia with NW activities are not necessarily a causality as the effect of myopia might force children to indoor confinement with more NW and less TSO. PA presented no effect on myopia. Though the strength of evidence is less because of high heterogeneity and lack of clinical trials with clear definition, increased TSO and reduced NW are protective against myopia development among nonmyopes.

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.

Recovery From Form-Deprivation Myopia in Chicks Is Dependent Upon the Fullness and Correlated Color Temperature of the Light Spectrum

Purpose

The purpose of this study was to evaluate the impact of full-spectrum light-emitting diodes mimicking sunlight (Sunlike LEDs) on ocular growth and refractive error development in a chicken model of myopia.

Methods

One-day old chicks (n = 39) were distributed into 3 groups and raised for 28 days in isoluminant (approximately 285 lux) fluorescent (n = 18, [FL-4000], correlated color temperature [CCT] = 4000 K) or Sunlike LED (n = 12, [SL-4000], CCT = 4000 K; n = 9, [SL-6500], CCT = 6500 K) white lighting environments. Form-deprivation myopia was induced monocularly from day 1 post-hatching (D1) until D14. On D14, form deprivation was halted and the recovery of form-deprived (FD) eyes was monitored until D28. Axial length (AL), refraction, choroidal thickness, and anterior chamber depth were measured in vivo on D1, D7, D14, D22, and D28. Differences in outcome measures between eyes and groups were compared using 2-way repeated-measures ANOVA.

Results

AL and myopic refraction of FD eyes increased similarly among groups during form-deprivation. FD eyes of animals raised under SL-4000 (D22: P < 0.001 and D28: P < 0.001) and SL-6500 (D22: P = 0.006 and D28: P < 0.001) recovered faster from axial elongation compared with animals raised under FL-4000. The refractive status of FD eyes reared under SL-6500, not under FL-4000 or SL-4000, was similar to control eyes on D28 (P > 0.05). However, SL-4000 and SL-6500 exhibited similar refraction on D28 than FL-4000 (P > 0.05). Choroidal thickness was significantly greater in FD eyes of chickens raised under SL-6500 than in animals raised under FL-4000 (P = 0.03).

Conclusions

Compared to fluorescent light, moderate intensities of full-spectrum Sunlike LEDs can accelerate recovery from form-deprivation myopia in chickens, potentially through a change in the choroid-mediated pathway.

Incidence and Progression of Myopia in Early Adulthood

IMPORTANCE

Myopia incidence and progression has been described extensively in children. However, few data exist regarding myopia incidence and progression in early adulthood.

OBJECTIVE

To describe the 8-year incidence of myopia and change in ocular biometry in young adults and their association with the known risk factors for childhood myopia.

DESIGN, SETTING, AND PARTICIPANTS

The Raine Study is a prospective single-center cohort study. Baseline and follow-up eye assessments were conducted from January 2010 to August 2012 and from March 2018 to March 2020. The data were analyzed from June to July 2021. A total of 1328 participants attended the baseline assessment, and 813 participants attended the follow-up assessment. Refractive information from both visits was available for 701 participants. Participants with keratoconus, previous corneal surgery, or recent orthokeratology wear were excluded.

EXPOSURES

Participants' eyes were examined at ages 20 years (baseline) and 28 years.

MAIN OUTCOMES AND MEASURES

Incidence of myopia and high myopia; change in spherical equivalent (SE) and axial length (AL).

RESULTS

A total of 516 (261 male [50.6%]) and 698 (349 male [50.0%]) participants without myopia or high myopia at baseline, respectively, were included in the incidences analyses, while 691 participants (339 male [49%]) were included in the progression analysis. The 8-year myopia and high myopia incidence were 14.0% (95% CI, 11.5%-17.4%) and 0.7% (95% CI, 0.3%-1.2%), respectively. A myopic shift (of 0.50 diopters [D] or greater in at least 1 eye) occurred in 261 participants (37.8%). Statistical significance was found in longitudinal changes in SE (-0.04 D per year; P < .001), AL (0.02 mm per year; P <.001), and lens thickness (0.02 mm per year; P < .001). Incident myopia was associated with self-reported East Asian vs White race (odds ratio [OR], 6.13; 95% CI, 1.06-35.25; P = .04), female vs male sex (OR, 1.81; 95% CI, 1.02-3.22; P = .04), smaller conjunctival ultraviolet autofluorescence area (per 10-mm2 decrease, indicating less sun exposure; OR, 9.86; 95% CI, 9.76-9.97; P = <.009), and parental myopia (per parent; OR, 1.57; 95% CI, 1.03-2.38; P = <.05). Rates of myopia progression and axial elongation were faster in female participants (estimate: SE, 0.02 D per year; 95 % CI, 0.01-0.02 and AL, 0.007 mm per year, 95 % CI, 0.00.-0.011; P ≤ .001) and those with parental myopia (estimate per parent: SE, 0.01 D per year; 95% CI, 0.00-0.02 and AL, 95% CI, 0.002-0.008; P ≤ .001). Education level was not associated with myopia incidence or progression.

CONCLUSIONS AND RELEVANCE

These findings suggest myopia progression continues for more than one-third of adults during the third decade of life, albeit at lower rates than during childhood. The protective effects of time outdoors against myopia may continue into young adulthood.

China Turns to School Reform to Control the Myopia Epidemic: A Narrative Review

ABSTRACT

Myopia is now a major public health issue in parts of East and Southeast Asia, including mainland China. In this region, around 80% of students completing 12 years of school education are now myopic, and from 10% to 20% have high myopia in excess of -6D. Interventions to prevent the onset of myopia based on increasing time outdoors have now been implemented at a system-wide scale in Chinese Taipei (Taiwan) and Singapore with some success, but the prevalence of myopia still remains high by international standards. In mainland China, until recently, myopia prevention was largely based on eye exercises, but these have not been sufficient to prevent an epidemic. Control of myopia progression with atropine eye drops has been widely practiced in Singapore and Taiwan, with recent practice concentrating on low-dose concentrations. Orthokeratology has also been widely used across the region. Recent research has produced both contact and spectacle lenses that slow myopia progression by imposing myopic defocus. The new approaches to myopia control are ready for systematic use, which may be facilitated by system-wide screening and referral. In recent years, renewed emphasis has been placed on the prevention of myopia in mainland China by China's President Xi Jinping. In addition to making use of all the measures outlined above, China now seems to be aiming for major reforms to schooling, reducing educational pressures, particularly in the early school years, freeing more time for outdoor play and learning. These new initiatives may be crucial to myopia prevention and control.

Light Intensity in Nursery Schools: A Possible Factor in Refractive Development

PURPOSE

Increased levels of outdoor light have been found to be associated causally with decreased rates of myopia. The goal of this study was to measure the effect of indoor nursery school light intensity on refraction of preschool children in Israel.

METHODS

A total of 1596 children aged 4 to 5 years from 27 nursery schools were examined. Light intensity was tested with a luxmeter device (Lux) inside and outside the nursery school. Noncycloplegic refractions were measured with the PlusOptix vision A09 screening device. Data analysis was performed using Pearson coefficients, chi-square tests for proportions and ANOVA tests by tertiles of illuminance.

RESULTS

This study included 1131 kindergarten children with a mean age of 4.87 ± 0.33 years, of which 571 were female (50.5%). The mean light intensity of the low, medium, and high intensity groups differed significantly (ANOVA P < 0.001) at 359 ± 2.64 lux (range 264-431), 490 ± 2.21 lux (range 432-574), and 670.76 ± 3.73 lux (range 578-804), respectively. Mean spherical equivalent (SE) was +0.56 ± 0.03D for the low-intensity group, +0.73 ± 0.03D for the medium-intensity group, and +0.89 ± 0.03D for the high-intensity group (ANOVA P < 0.001). The low-intensity group had 42.1% of children with zero refraction or less, while the high-intensity group had 19.3%.

CONCLUSIONS

In the nursery schools, lower amounts of illumination were associated with less hyperopic refractive error. As the low hyperopic reserve is a risk factor for developing myopia, this finding needs to be followed up to establish whether this association reflects a causal relationship, which could be modulated for the prevention of myopia.

Low-intensity, long-wavelength red light slows the progression of myopia in children: an Eastern China-based cohort

PURPOSE

To determine the effect of low-intensity, long-wavelength red light therapy (LLRT) on the inhibition of myopia progression in children.

METHODS

A retrospective study was conducted. One hundred and five myopic children (spherical equivalent refractive error [SER] -3.09 ± 1.74 dioptres [D]; mean age, 9.19 ± 2.40 years) who underwent LLRT treatment (power 0.4 mW, wavelength 635 nm) twice per day for 3 min each session, with at least a 4-h interval between sessions, and a control group of 56 myopic children (SER -3.04 ± 1.66 D; mean age, 8.62 ± 2.45 years) were evaluated. Both groups wore single-vision distance spectacles. Each child returned for a follow-up examination every 3 months after the initial measurements for a total of 9 months.

RESULTS

At 9 months, the mean SER in the LLRT group was -2.87 ± 1.89 D, significantly greater than that of the control group (-3.57 ± 1.49 D, p < 0.001). Axial length (AL) changes were -0.06 ± 0.19 mm and 0.26 ± 0.15 mm in the LLRT group and control group (p < 0.001), respectively. The subfoveal choroidal thickness changed by 45.32 ± 30.88 μm for children treated with LLRT at the 9-month examination (p < 0.001). Specifically, a substantial hyperopic shift (0.31 ± 0.24 D and 0.20 ± 0.14 D, respectively, p = 0.02) was found in the 8-14 year olds compared with 4-7 year old children. The decrease in AL in subjects with baseline AL >24 mm was -0.08 ± 0.19 mm, significantly greater than those with a baseline AL ≤24 mm (-0.04 ± 0.18 mm, p = 0.03).

CONCLUSIONS

Repetitive exposure to LLRT therapy was associated with slower myopia progression and reduced axial growth after short durations of treatment. These results require further validation in randomised controlled trials.

Evaluation of an Optical Defocus Treatment for Myopia Progression Among Schoolchildren During the COVID-19 Pandemic

IMPORTANCE

Myopia progression has been found to be worsening during the COVID-19 pandemic. It is important to control the rapid myopia progression in this period.

OBJECTIVE

To analyze the association of COVID-19-related lockdown measures with myopia progression in schoolchildren and to compare the performance of defocus incorporated multiple segments (DIMS) lens with that of single vision lens (SVL) treatment in reducing myopia progression.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study involved an exploratory, prespecified, comparison of 2 independent longitudinal studies performed at the same institute beginning in 2019. Data from Hong Kong schoolchildren (aged 7-13 years) were gathered and analyzed. Data analysis was performed from June to July 2021.

EXPOSURE

Schoolchildren in study 1 wore a DIMS lens for 18 months, and those in study 2 wore a SVL for 24 months.

MAIN OUTCOMES AND MEASURES

Cycloplegic spherical equivalent refraction and axial length were measured. Studies 1 and 2 started before the start of lockdown measures and continued throughout the lockdown. In both studies, periods of fewer and more COVID-19-related lockdown measures were identified. Because COVID-19 lockdown caused deviations from the visit schedule, myopia progression was normalized to 12-month change, which were compared between DIMS and SVL groups, also during the periods with less and more lockdown time.

RESULTS

There were 115 participants (58 girls [50.4%]; mean [SD] age, 10.3 [1.5] years) in the DIMS group; their mean (SD) baseline refraction was -4.02 (1.46) D. There were 56 participants (29 girls [51.8%]; mean [SD] age, 10.8 [1.5] years) in the SVL group; their mean (SD) baseline refraction was -2.99 (1.06) D. After controlling for the covariates, DIMS treatment was significantly associated with 34% less axial elongation (0.19 mm [95% CI, 0.16 to 0.22 mm] vs 0.30 mm [95% CI, 0.25 to 0.35 mm]; P < .001) and 46% less myopic progression after 12 months (-0.31 D [95% CI, -0.39 to -0.23 D] vs -0.57 D [95% CI, -0.69 to -0.45 D]; P = .001) compared with SVL treatment. In both the DIMS and SVL groups, more lockdown time was associated with significantly more spherical equivalent refraction (-0.54 D [95% CI, -0.64 to 0.44 D] vs -0.34 D [95% CI, -0.44 to -0.25 D]; P = .01) and axial length (0.29 mm [95% CI, 0.25 to 0.32 mm] vs 0.20 mm [95% CI, 0.16 to 0.24 mm]; P = .001) compared with less lockdown time. No significant interaction between treatment type and lockdown time was observed.

CONCLUSIONS AND RELEVANCE

In this exploratory analysis, myopia progressed more rapidly in schoolchildren during the period when there were more COVID-19-related lockdown measures. However, optical treatment with DIMS was significantly associated with slower myopia progression compared with SVL treatment during the lockdown period.

Predicting factors for progression of the myopia in the MiSight assessment study Spain (MASS)

PURPOSE

To investigate which baseline factors are predictive for success in controlling myopia progression in a group of children wearing MiSight Contact Lens (CLs).

METHODS

Myopic patients (n=41) fitted with MiSight CLs and followed up two years were included in this study. Bivariate analysis, a logistic regression analysis (LG) and a decision tree (DT) approach were used to screen for the factors influencing the success of the treatment. To assess the response, axial length (AL) changes were considered as main variable. Patients were classified based on a specific range of change of axial length at the end of each year of treatment as "responders" (R) (AL change <0.11mm/per year) and "non-responders" (NR) (AL change ≥0.11mm/per year).

RESULTS

Of a total of forty-one Caucasian patients treated with MiSight CLs, 21 and 16 were considered responders in the first and the second year of follow-up, respectively. LG analysis showed that the only factor associated with smaller axial length growth was more time spent outdoors (p=0.0079) in the first year of treatment. The decision tree analysis showed that in the responding group spending more than 3 and 4h outdoors per week was associated with the best response in the first year and in the second year of treatment respectively.

CONCLUSIONS

The LR and the DT approach of this pilot study identifies time spent outdoors as a main factor in controlling axial eye growth in children treated with MiSight CLs.

Is there still evolution in the human population?

It is often claimed that humanity has stopped evolving because modern medicine erased all selection on survival. Even if that would be true, and it is not, there would be other mechanisms of evolution which could still led to changes in allelic frequencies. Here I show, by applying basic evolutionary genetics knowledge, that we expect humanity to evolve. The results from genome sequencing projects have repeatedly affirmed that there are still recent signs of selection in our genomes. I give some examples of such adaptation. Then I briefly discuss what our evolutionary future has in store for us.

Progression of myopia in teenagers and adults: a nationwide longitudinal study of a prevalent cohort

BACKGROUND

The prevalence of myopia is increasing worldwide. The purpose of this study was to evaluate the progression of myopia in teenagers and adults in France.

METHODS

This nationwide prospective study followed 630 487 myopic adults and teenagers (mean age 43.4 years±18.2, 59.8% of women) between January 2013 and January 2019. Myopia and high myopia were defined as a spherical equivalent less than or equal to -0.50 and -6.00 diopters (D), respectively. Demographic data were collected at first visit and refractive characteristics were collected at each visit. Analysis of short-term progression (first 12 to 26 months postbaseline) was modelled using analysis of variance (ANOVA). Progression of myopia was stratified according to age, gender and spherical equivalent at first visit.

RESULTS

Higher proportions of progressors were observed in the youngest age groups: 14-15 (18.2 %) and 16-17 years old (13.9 %). In multivariate analysis, after adjustment for over age, spherical equivalent and gender, the mean short-term progression decreased from -0.36 D in the 14-15 years age group to -0.13 D in the 28-29 years age group. Young age and higher myopia at baseline together were strongly associated with the risk of developing high myopia, the 5-year cumulative risk being 76% for youngest teenager with higher myopia status at baseline.

CONCLUSION

In this large cohort of myopic teenagers and adults, myopia progression was reported in 18.2% and 13.9% of the 14-15 and 16-17 age groups, respectively. The risk to develop high myopia was higher for younger individuals with higher myopia at baseline examination.

Online Learning-Related Visual Function Impairment During and After the COVID-19 Pandemic

This study aimed to review the consequences of increased online learning, which was precipitated by the coronavirus disease 2019 (COVID-19), on visual function, as well as the methods for preventing the associated visual impairment. The recent finding implies that a higher incidence of myopia may be observed during the pandemic than that before. The myopia prevalence was 59.35% in COVID-19, which was higher than that in the normal period. COVID-19-related influence of developing myopia among students should be addressed and under control. Online learning precipitated by COVID-19 is likely to increase the global burden of visual function impairment. This review highlighted useful measures to prevent online learning-related visual function impairments, including the following: (1) desktop illumination of no >300 lx, online learning time for primary, and middle-school students of no more than 20–30 min per session; (2) daily video time for preschool children not exceeding 1 h, and for school-age children and adolescents not exceeding 2 h; (3) after every 30–40 min of online learning, moving eyes away from the screen or closed for 10 min; (4) engaging in outdoor activities for ≥ 2 h a day; (5) suitable screen and learning environment settings and correct postures for reading and writing; (6) sufficient sleep and proper nutrition. Preventing online learning-related visual impairment during and after this unprecedented pandemic will facilitate future ophthalmic practice.

"Emmetropic, but not myopic human eyes distinguish positive defocus from calculated defocus in monochromatic red light"

Studies in animal models have provided evidence that broadband light and chromatic cues are necessary for successful emmetropization. We have studied this question in young human subjects by measuring short-term changes in axial length when they watched movies with calculated defocus (2.5D) or optically defocused movies (+2.5D) with red interference filters (620 ± 10 nm). Since filters cut luminance down by a factor of 10, a control experiment with neutral density filters (ND 1.0) was done. Ten myopes and 10 emmetropes were studied. Four experimental conditions were tested on two separate days. On the first day, movies with calculated defocus, and defocused by positive lenses were watched with ND filters. On the second day, movies with the same defocus patterns were watched with the red filters. Movies were presented on a large TV screen (LG OLED65C9, 65″) in a dark room at 2 m distance for 30 min. Changes in axial length before and after each stimulation were measured with the Lenstar (LS 900, with autopositioning system; Haag-Streit). Interestingly, the effects of calculated defocus or optical positive defocus on axial length were suppressed by 1.0 ND filters in myopes and emmetropes, with no clear trend. In contrast, narrow-band red light suppressed eye elongation with calculated defocus but not eye shortening with positive defocus in emmetropes. In myopes, as previously found in white light, there was a trend of axial eye elongation with positive lenses. In conclusion, the effect of positive lenses on eye growth did not require chromatic cues.

Dietary intake and associations with myopia in Singapore children

PURPOSE

To evaluate associations of dietary factors with myopia, spherical equivalent refractive error (SE) and axial length (AL) in children at age 9 from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort.

METHODS

We included 467 multi-ethnic children (933 eyes) who participated in the GUSTO prospective birth cohort and were delivered in two major hospitals in Singapore (2009-2010). At the 9-year visit, we assessed the 6-year incidence of myopia (between ages 3 to 9), cycloplegic SE and AL in children without myopia (SE ≤ -0.5 D in either eye) at the 3-year visit. Using a validated 112-item food frequency questionnaire, parents reported each child's average daily intake of dietary factors (nutrients and food groups) in the past month. Paired eyes were analysed using Generalised Estimating Equations with multivariable logistic or linear regression. Bonferroni corrections were applied, correcting for multiple comparisons between the 13 nutrients (p < 0.004) or 8 food groups (p < 0.006) and each outcome.

RESULTS

In children aged 9 years (51.0% boys; 56.3% Chinese), the 6-year incidence of myopia was 35.5%. Overall, the mean (SD) SE and AL were -0.3 (1.7) D and 23.4 (1.0) mm, respectively. In multivariable regression, macronutrients or micronutrients were not associated with incident myopia (p ≥ 0.004 for all), adjusting for total energy, gender, ethnicity, time outdoors, near-work and the number of myopic parents (additionally child's height for outcome AL). Similarly, all food groups (including refined grains, sugar-sweetened beverages, protein foods, fruits and vegetables) were not associated with incident myopia (p ≥ 0.006 for all). Additionally, none of the nutrients (p ≥ 0.004 for all) or food groups (p ≥ 0.006 for all) were associated with SE or AL.

CONCLUSIONS

Our study findings of no significant association between specific nutrients or food groups and incident myopia or SE or AL suggest that diet may not be associated with myopia in children aged 9 years. Well-conducted prospective studies in other populations may clarify the association.

Relationship between axial length and spherical equivalent refraction in Chinese children

Purpose

To evaluate the relationship between axial length (AL) and spherical equivalent refraction (SER) in Chinese children.

Methods

This hospital-based cross-sectional study included 1208 eyes (from 617 Chinese boys and 591 Chinese girls), ranging between 2 and 12 years. All subjects were divided into subgroups according to the spherical equivalent refraction (SER) (hyperopia, emmetropia, and myopia) and age (2-6 years, 7-9 years, and 10-12 years). Comparisons were made between age, sex, and SER groups. Multiple linear regression analysis was used to evaluate the correlation of AL and SER for all groups.

Results

The mean AL and SER were significantly different among the three age groups: 2-6 years group (AL: 22.24 ​± ​1.59 ​mm; SER: 0.73 ​± ​2.67 D); 7-9 years group (AL: 23.49 ​± ​1.10 ​mm; SE: -0.68 ​± ​1.97 D) and 10-12 years group (AL: 24.33 ​± ​1.02 ​mm; SER: -1.72 ​± ​1.86 D). Boys showed longer AL compared with the girls (23.66 ​± ​1.51 ​mm vs 23.05 ​± ​1.32 ​mm). However, as for SER, the girls (-0.70 ​± ​2.17 D) showed smaller SER (more myopia) compared with the boys (-0.4 ​± ​2.48 D). After adjusting for age and sex, the SER tended to decrease (became more myopic) 1.23 D (95% CI: 1.15-1.30D) with a 1 ​mm increase of AL. Among the different SER groups, the SER tended to become more myopic per mm of AL by 1.09 D (95% CI: 0.97-1.21D) for the myopia group, 1.38 D (95% CI: 1.23-1.54 D) for the hyperopia group, and 0.05 D (95% CI: 0.02-0.08 D) for the emmetropic group. In addition, an increase of 1 ​mm elongation of AL showed a decrease of SER by 1.05 D (95% CI: 0.90-1.20 D) among 2 - 6-year-olds, by 1.40 D (95% CI: 1.30-1.51 D) among 7 - 9-year-olds, and by 1.37 D (95% CI: 1.21-1.52 D) among 10-12-year-olds. As for sexual differences, the girls 1.68 D, (95% CI: 1.57-1.79 D) showed a more significant myopic shift of SER with a 1 ​mm increase of AL compared with the boys (0.94 D, 95% CI: 0.84-1.04 D).

Conclusions

Our results indicated a strong linear relationship between SER and AL and an early-rising trend of myopia in Chinese children.

Effect of Repeated Low-Level Red-Light Therapy in Myopia Control in Children: A Multicenter Randomized Controlled Trial

PURPOSE

To assess the efficacy and safety of repeated low-level red-light (RLRL) therapy in myopia control in children.

DESIGN

Multicenter, randomized, parallel-group, single-blind clinical trial.

PARTICIPANTS

A total of 264 eligible children aged 8 to 13 years with myopia of cycloplegic spherical equivalent refraction (SER) of -1.00 to -5.00D, astigmatism < 2.50D, anisometropia < 1.50D, best-corrected visual acuity (BCVA) >0.0 logMAR (Snellen 1.0 or 20/20) were enrolled in July to August 2019. Follow-up was completed in September 2020.

METHODS

Children were randomly assigned to the intervention group [RLRL treatment plus single vision spectacle (SVS)] and control group (SVS). The RLRL treatment was provided by a desktop light therapy device which emits red light of 650 nm in wavelength, at an illuminance level of approximately 1600 lux and a power of 0.29 mW for a 4-mm pupil (Class I Classification), and was administered at home under supervision of parents, 3 minutes per session, twice per day with a minimum interval of 4-hours, five days per week.

MAIN OUTCOME MEASURES

The primary outcome and a key secondary outcome were changes in axial length (AL) and SER measured at baseline, and 1-, 3-, 6- and 12-month follow-up visits. Participants who had at least one post-randomization follow-up visit were analyzed for treatment efficacy based on a longitudinal mixed model.

RESULTS

Among 264 randomized participants, 246 (93.2%) children were included in the analysis (n = 117 in the RLRL and n = 129 in the SVS group). Adjusted 12-month axial elongation and SER progression were 0.13 mm (95% CI: 0.09 to 0.17) and -0.20 D (95% CI: -0.29 to -0.11) for RLRL treatment, 0.38 mm (95% CI: 0.34 to 0.42) and -0.79 D (95%CI, -0.88 to -0.69) for SVS. The difference in axial elongation and SER progression were 0.26 mm (95% CI: 0.20 to 0.31) and -0.59 D (95% CI: -0.72 to -0.46) between the RLRL and SVS groups. No severe adverse events (sudden vision loss by 2 lines or scotoma developed), functional visual loss indicated by BCVA, or structural damage seen on optical coherence tomography scans were observed.

CONCLUSIONS

RLRL therapy is a promising alternative treatment for myopia control in children with good user acceptability and no documented functional and structural damages.

Peripheral refraction of myopic eyes with spectacle lenses correction and lens free emmetropes during accommodation

PURPOSE

To measure axial and off-axis refraction patterns in myopic eyes with spectacle lenses correction and lens free emmetropes in young healthy subjects at different target distances from 2.00 m (0.50 D) to 0.20 m (5.00 D) in terms of sphere, astigmatism, and spherical equivalent refraction.

METHODS

Refraction was measured at the center, 20 and 40 degrees from the line of sight both nasally and temporally in 15 emmetropic and 25 myopic young healthy subjects with an open field, binocular, infrared autorefractor (Grand Seiko WAM-5500, Hiroshima, Japan). Fixation target was a Maltese cross set at 2.00, 0.50, 0.33 and 0.20 m from the corneal plane. Changes in off-axis refraction with accommodation level were normalized with respect to distance axial values and compared between myopic eyes with spectacle lenses correction and lens free emmetropes.

RESULTS

Off-axis refraction in myopic eyes with spectacle lenses correction was significantly more myopic in the temporal retina compared to lens free emmetropes except for the closest target distance. Relative off-axis refractive error changed significantly with accommodation when compared to axial refraction particularly in the myopic group. This change in the negative direction was due to changes in the spherical component of refraction that became more myopic relative to the center at the 0.20 m distance as the J0 component of astigmatism was significantly reduced in both emmetropes and myopes for the closest target.

CONCLUSION

Accommodation to very near targets (up to 0.20 m) makes the off-axis refraction of myopes wearing their spectacle correction similar to that of lens free emmetropes. A significant reduction in off-axis astigmatism was also observed for the 0.20 m distance.

Digital Therapeutics: Exploring the Possibilities of Digital Intervention for Myopia

Pediatric myopia is increasing globally and has become a major public health issue. However, the mechanism of pediatric myopia is still poorly understood, and there is no effective treatment to prevent its progression. Based on results from animal and clinical studies, certain neuronal–humoral factors (NHFs), such as IGF-1, dopamine, and cortisol may be involved in the progression of pediatric myopia. Digital therapeutics uses evidence-based software as therapeutic interventions and it has the potential to offer innovative treatment strategies for pediatric myopia beyond conventional treatment methods. In this perspective article, we introduce digital therapeutics SAT-001, a software algorithm that modulates the level of NHFs to reduce the progression of pediatric myopia. The proposed mechanism is based on a theoretical hypothesis derived from scientific research and clinical studies and will be further confirmed by evidence generated from clinical studies involving pediatric myopia.

Effects of Parental Involvement in a Preschool-Based Eye Health Intervention Regarding Children's Screen Use in China

In this digital era, young children spend a considerable amount of time looking at telephone, tablet, computer and television screens. However, preventative eye health behavior education could help avoid and relieve asthenopia. The effects of parental influence on their children's eye health behavior through the preschool eye health education intervention program were examined. The Health Belief Model was used to develop parental involvement strategy and eye health curriculum. The study was conducted in a large public preschool with five branches in Beijing, China. A total of 248 parent-child pairs participated in the baseline and follow-up surveys, of which 129 were in the intervention group and 119 were in the comparison group. The generalized estimating equation analysis results indicated that parental involvement in preschool-based eye health intervention on screen uses had positive influence on parents' eye health knowledge, cues to action, and parenting efficacy. The intervention program also had positive effects on the increasing level of children's eye health knowledge, beliefs, cues to action, self-efficacy, and behaviors. The results supported the implementation of a preschool-based eye health intervention program with parental involvement, which could potentially enhance children's and parents' eye health beliefs and practices.

Dietary ω-3 polyunsaturated fatty acids are protective for myopia

Myopia is a leading cause of visual impairment and blindness worldwide. However, a safe and accessible approach for myopia control and prevention is currently unavailable. Here, we investigated the therapeutic effect of dietary supplements of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on myopia progression in animal models and on decreases in choroidal blood perfusion (ChBP) caused by near work, a risk factor for myopia in young adults. We demonstrated that daily gavage of ω-3 PUFAs (300 mg docosahexaenoic acid [DHA] plus 60 mg eicosapentaenoic acid [EPA]) significantly attenuated the development of form deprivation myopia in guinea pigs and mice, as well as of lens-induced myopia in guinea pigs. Peribulbar injections of DHA also inhibited myopia progression in form-deprived guinea pigs. The suppression of myopia in guinea pigs was accompanied by inhibition of the "ChBP reduction-scleral hypoxia cascade." Additionally, treatment with DHA or EPA antagonized hypoxia-induced myofibroblast transdifferentiation in cultured human scleral fibroblasts. In human subjects, oral administration of ω-3 PUFAs partially alleviated the near-work-induced decreases in ChBP. Therefore, evidence from these animal and human studies suggests ω-3 PUFAs are potential and readily available candidates for myopia control.

Associations of 12-year sleep behaviour trajectories from childhood to adolescence with myopia and ocular biometry during young adulthood

PURPOSE

Cross-sectional studies have variably reported that poor sleep quality may be associated with myopia in children. Longitudinal data, collected over the ages when myopia develops and progresses, could provide new insights into the sleep-myopia paradigm. This study tested the hypothesis that 12-year trajectories of sleep behaviour from childhood to adolescence is associated with myopia during young adulthood.

METHODS

At the 5-, 8-, 10-, 14- and 17-year follow-ups of the longitudinal Raine Study, which has been following a cohort since their birth in 1989-1992, participants' parents/guardians completed the Child Behaviour Checklist questionnaire (CBCL), which collected information on their child's sleep behaviour and quality. The CBCL includes six questions measuring sleep behaviour, which parents rated as 0 = not true, 1 = somewhat/sometimes true, or 2 = very/often true. Scores were summed at each follow-up to form a composite "sleep behaviour score". Latent Class Growth Analysis (LCGA) was used to classify participants according to their 12-year trajectory of sleep behaviour. At the 20-year follow-up, an eye examination was performed which included cycloplegic autorefraction and axial length measurement.

RESULTS

The LCGA identified three clusters of participants based on their trajectory of sleep behaviour: those with minimal' (43.6% of the total Raine Study sample), 'declining' (48.9%), or 'persistent' (7.5%) sleep problems. A total of 1194 participants had ophthalmic data and longitudinal sleep data available for analysis (47.2% female, 85.6% Caucasian). No significant differences were observed in regards to age, sex, ethnicity or ocular parameters between trajectory groups. Unadjusted and fully adjusted analyses demonstrated that sleep problem behaviour was not significantly associated with changes in refractive error, axial length or corneal radius.

CONCLUSIONS

Our findings do not support the hypothesis that there is an association between sleep behaviour and myopia. Future longitudinal studies should explore sleep trajectory data pre- and post-myopia diagnosis to confirm our results.

Prevalence and pattern of refractive error and visual impairment among schoolchildren: the Lhasa childhood eye study

Background

Early and effective ocular screening may help to eliminate treatable eye disorders. The Lhasa Childhood Eye Study (LCES) revealed the particular prevalence of refractive error and visual impairment in grade one schoolchildren (starting age of 6 years old) in Lhasa.

Methods

This is a cross-sectional part of school-based cohort study. One thousand nine hundred forty-three children were enrolled (median age, 6.78 years, range, 5.89 to 10.32). Each child underwent general and ocular examinations, including logarithm of the minimum angle of resolution (logMAR) visual acuity, cycloplegic autorefraction, and slit-lamp biomicroscopy evaluation. Multivariate and correlation analyses were performed to evaluate the association between refractive error with gender and ethnics.

Results

The prevalence of visual impairment (logMAR visual acuity ≥0.3 in the better-seeing eye) of uncorrected, presenting and best-corrected visual acuity (BCVA) was 12.2, 11.7 and 2.7%, respectively. Refractive error presented in 177 (78.0%) out of 227 children with bilateral visual impairment. Myopia (spherical equivalent refractor [SER] ≤ − 0.50 diopter [D] in either eye) was present in 4.7% children when measured after cycloplegic autorefraction. Hyperopia (SER ≥ + 2.00 D) affected 12.1% children. Hyperopia was significantly associated with female gender (P<0.001). Astigmatism (cylinder value ≤ − 0.75 D) was present in 44.8% children. In multivariate regression and correlation analysis, SER had no significant difference between ethnic groups.

Conclusion

The Lhasa Childhood Eye Study is the first school-based cohort study to reveal the prevalence and pattern of refractive error and visual impairment in Lhasa. Effective strategies such as corrective spectacles should be considered to alleviate treatable visual impairment.

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.

Is myopia prevalence related to outdoor green space?

PURPOSE

Rapid urbanisation and lifestyle changes have been associated with a huge increase in myopia across many parts of the world. There is strong evidence that environmental factors including time outdoors and urbanisation can influence the development of myopia, particularly in school-aged children. The aim of this study is to determine whether there is a relationship between the prevalence of myopia and the amount of vegetation/green spaces across different regions of the world, as a risk factor for myopia development.

METHODS

The prevalence of myopia in the 15 to 19-year age group in Australia, Brazil, China, Finland, India, Iran, Japan, Oman, Singapore, South Africa and the UK was obtained from a meta-analysis by Holden et al. Normalised Difference Vegetation Index (NDVI) was used to quantify green space exposure based on Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite data. Green space was measured in locations specific to 15 studies that reported myopia prevalence. Simple linear regression was used to analyse yearly data, and a mixed effects model was applied to assess the significance of green space when study was a random effect.

RESULTS

Myopia prevalence increases significantly when green space was <-0.2, but the effect was less apparent for values >-0.1. When a mixed effects model was used, the effect of green space was found to be significantly associated with myopia prevalence (p = 0.05).

CONCLUSIONS

There was evidence of a weak but significant non-linear relationship between myopia and green space, with the effect most apparent at low levels of green space. A larger data sample, along with further investigations into the utilisation of green spaces, are required to understand whether increasing the amount of green space can reduce myopia incidence and progression impact.

Impact of the Pressure-Free Yutori Education Program on Myopia in Japan

This study aimed to investigate the influence of educational pressure on myopia. A less-intense school curriculum was introduced nationally in Japan beginning in 2012 based on a pressure-free education policy. In this retrospective observational study, a total of 1025 Japanese medical students of Asahikawa Medical University underwent measurements of the cycloplegic refractive error and axial length (AL), from 2011 to 2020. The spherical equivalent (SE) and AL were correlated significantly with the fiscal year of births (p = 0.004 and p = 0.034, respectively) only during enforcement of the system of high-pressure education. The SE and AL regression rates during the two educational approaches differed significantly (p = 0.004 and p = 0.037, respectively). The prevalence of high myopia was correlated significantly (p < 0.001) only during the system of high-pressure education. The regression of the prevalence rate of high myopia during the two education approaches differed significantly (p = 0.010). The progression rates of myopia and increased prevalence of high myopia were observed only during high-pressure education, suggesting that not only ophthalmologists but also educators and the government should work on together to control the progression of myopia.

Time spent outdoors through childhood and adolescence - assessed by 25-hydroxyvitamin D concentration - and risk of myopia at 20 years

PURPOSE

To investigate the relationship between time spent outdoors, at particular ages in childhood and adolescence, and myopia status in young adulthood using serum 25-hydroxyvitamin D [25(OH)D] concentration as a biomarker of time spent outdoors.

METHODS

Participants of the Raine Study Generation 2 cohort had 25(OH)D concentrations measured at the 6-, 14-, 17- and 20-year follow-ups. Participants underwent cycloplegic autorefraction at age 20 years, and myopia was defined as a mean spherical equivalent -0.50 dioptres or more myopic. Logistic regression was used to analyse the association between risk of myopia at age 20 years and age-specific 25(OH)D concentrations. Linear mixed-effects models were used to analyse trajectory of 25(OH)D concentrations from 6 to 20 years.

RESULTS

After adjusting for sex, race, parental myopia, body mass index and studying status, myopia at 20 years was associated with lower 25(OH)D concentration at 20 years (per 10 nmol/L decrease, odds ratio (aOR)=1.10, 95% CI: 1.02, 1.18) and a low vitamin D status [25(OH)D < 50 nmol/L] at 17 years (aOR = 1.71, 95% CI: 1.06, 2.76) and 20 years (aOR = 1.71, 95% CI: 1.14, 2.56), compared to those without low vitamin D status. There were no associations between 25(OH)D at younger ages and myopia. Individuals who were myopic at 20 years had a 25(OH)D concentration trajectory that declined, relative to non-myopic peers, with increasing age. Differences in 25(OH)D trajectory between individuals with and without myopia were greater among non-Caucasians compared to Caucasians.

CONCLUSIONS

Myopia in young adulthood was most strongly associated with recent 25(OH)D concentrations, a marker of time spent outdoors.

Topical Review: Bibliometric Analysis of the Emerging Field of Myopia Management

SIGNIFICANCE

Identification of the most impactful articles, authors, institutions, countries, and journals in myopia management provides a useful baseline reference for clinicians, researchers, and funding agencies in respect of this emerging field.This work aims to assemble publication metrics for myopia management to identify the most impactful articles, authors, institutions, countries, and journals in this emerging field of research. A search of the titles of articles was undertaken on the Scopus database to identify myopia management-related articles. The 25 most highly cited articles were determined from the total list of 1064 articles found. Rank-order lists by count were assembled for the top 25 in each of four categories: authors, institutions, countries, and journals. A subject-specific myopia management-related h-index (hMM-index) was derived for the entire field, in addition to each of the four categories, to serve as measures of impact in the field. Top 15 lists were generated for each category ranked by hMM-index and tabulated for consideration. An article by Christine Wildsoet and colleagues, describing choroidal and scleral mechanisms of compensation for spectacle lenses in chicks, has generated the most citations (412); Earl Smith is the most impactful author (hMM = 19); the University of Houston produces the most impactful articles (hMM = 31); the United States is the most highly ranked country (hMM = 60); and Optometry and Vision Science is the most impactful journal. Although still in its infancy, myopia management is a topic of emerging interest in the clinical and scientific ophthalmic literature. Impactful authors, institutions, countries, and journals are identified. Optometry is revealed as the leading profession in relation to the publication of myopia management-related articles.

Objective and Subjective Behavioral Measures in Myopic and Non-Myopic Children During the COVID-19 Pandemic

Purpose

The coronavirus disease 2019 (COVID-19) pandemic required a shift to electronic devices for education and entertainment, with children more confined to home, which may affect eye growth and myopia. Our goal was to assess behaviors during COVID-19 in myopic and non-myopic children.

Methods

Parents completed a questionnaire for their children (ages 8.3 ± 2.4 years, n = 53) regarding visual activity in summer 2020, during the COVID-19 pandemic, as well as during school time and the summer before COVID-19. Children also wore an Actiwatch for 10 days in summer 2020 for objective measures of light exposure, activity, and sleep. Data were analyzed with repeated-measures analysis of variance.

Results

Subjective measures showed that during COVID-19, children exhibited increased electronic device use and decreased activity and time outdoors (P < 0.05 for all), while time spent doing near work was not different than during a typical school or summer session before COVID-19 (P > 0.05). Objective measures during COVID-19 showed that myopic children exhibited lower daily light exposure (P = 0.04) and less activity (P = 0.04) than non-myopic children.

Conclusions

Children demonstrated increased electronic device use and decreased activity and time outdoors during COVID-19, with myopic children exhibiting lower light exposure and activity than non-myopes. Long-term follow-up is needed to understand if these behavioral changes ultimately contribute to myopia progression.

Translational Relevance

Children's behaviors changed during the COVID-19 pandemic, which may have implications in eye growth and myopia.

Stepwise low concentration atropine for myopic control: a 10-year cohort study

The aim of this study was to analyze changes in refraction and evaluate the variables in school children who received atropine as myopic control for 10 years. Low-concentration atropine (0.05%) was prescribed initially, and the dose was increased in a stepwise manner if rapid myopic progression (≥ 0.5D per half year) was noted during the regular follow-up visit. 23 children with a mean age of 6.96 ± 1.07 years were included. The initial spherical equivalent was − 1.25 ± 0.84 D. The overall mean myopic progression was − 0.30 ± 0.27 D/year. Younger initial age, female, higher initial spherical equivalent and the need of higher concentration of atropine were found to be risk factors for myopic progression in multivariate mixed-effect analysis (p = 0.013, 0.017, 0.024 and 0.014). Children who kept using a lower concentration of atropine (≤ 0.1%) tended to have slower myopic progression throughout the 10-year course than those who shifted to higher concentrations (> 0.1%) (p ≤ 0.001). Stepwise low concentration of atropine might be effective for long-term myopic control in school students. Those who had poor response to lower concentration of atropine may have the risk of faster progression, even with high concentration of atropine. Additional or alternative treatment might be considered.

Prevalence of Self-Reported Symptoms of Computer Vision Syndrome and Associated Risk Factors among School Students in China during the COVID-19 Pandemic

PURPOSE

To determine the prevalence and risk factors of self-reported symptoms of Computer Vision Syndrome (CVS) in school students during COVID-19 pandemic.

METHODS

In this cross-sectional study in Nanjing, China, students (grades 1-12) from six randomly selected schools self-administered the online survey questionnaire about hours on electronic devices, outdoor activities, frequency and intensity of 17 CVS symptoms during virtual learning period of COVID-19 pandemic.

RESULTS

Among 2363 invited students, 2005 (84.8%) completed the survey. Mean (SD) age was 12 (3.0) years, 51% were male, 53% wore glasses, 56% did not know the 20-20-20 rule (take a 20 second break every 20 min of close work and gaze at objects at least 20 feet away) and 6.5% knew but never followed the 20-20-20 rule. Mean (SD) hours/day was 4.6 (3.4) for screen time and 1.2 (1.0) for outdoor activities. Total of 1543 (77.0%) students reported at least one CVS symptom (median = 4) with eye dryness and itching the most common (48%). In multivariable analysis, CVS score 4 or more was independently associated with older age (adjusted odds ratio (aOR) = 1.05 for per-year increase, p = 0.02), children with myopia not wearing glasses (aOR = 2.12, p = 0.0003), astigmatism (aOR = 1.37, p = 0.04), other ocular diseases (aOR = 1.59, p = 0.005), not complying 20-20-20 rule (aOR = 2.13, p = 0.04), more screen time (aOR = 1.53 for >6 vs. ≤2 hours, p = 0.0001) and less outdoor activities (aOR = 1.37 for ≤0.6 vs. ≥1.9 hours, p = 0.005).

CONCLUSIONS

During COVID-19 pandemic, self-reported CVS symptoms occurred in more than three-quarters of students. Besides pre-existing ocular diseases, children with myopia not wearing glasses, excessive time on screens, non-compliance of the 20-20-20 rule and reduced outdoor activities were associated with higher risk of CVS.

Prevalence Trend of Myopia after Promoting Eye Care in Preschoolers: A Serial Survey in Taiwan before and during the Coronavirus Disease 2019 Pandemic

PURPOSE

To report the prevalence of preschool myopia after implementing a policy intervention promoting outdoor activities and the secular trend of myopia before and during the coronavirus disease 2019 (COVID-19) pandemic in a Taiwan preschool population.

DESIGN

Repeated countywide population-based, cross-sectional surveys based on the Yilan Myopia Prevention and Vision Improvement Program (YMVIP).

PARTICIPANTS

Among 23 930 kindergarteners 5 to 6 years of age from 7 school-year cohorts in Yilan County from 2014 through 2020, a total of 21 761 children (90.9%) were included for analysis.

METHODS

Since launching the YMVIP in August 2014, myopia prevention strategies, such as increasing outdoor activities (2 hours/weekday), have been promoted in all kindergartens, and countywide school-based eye examinations, including cycloplegic autorefraction, and caregiver-administered questionnaires have been carried out annually for all participants.

MAIN OUTCOME MEASURES

The prevalence of myopia (spherical equivalent, ≤ -0.5 D in either eye) in each of the 7 school-year cohorts of preschoolers 5 to 6 years of age.

RESULTS

The prevalence of myopia continuously decreased for 2 years after implementing the YMVIP: 2014 cohort, 15.5% (95% confidence interval [CI], 14.2%-16.8%); 2015 cohort, 13.5% (95% CI, 12.3%-14.7%); and 2016 cohort, 8.4% (95% CI, 7.4%-9.4%). Subsequent cohorts were exposed maximally to these school-based myopia prevention strategies, and the prevalence of myopia remained relatively stable, between 8.5% and 10.3%, even during the COVID-19 pandemic. Multivariate logistic regression analysis showed a dose-dependent association between the duration of exposure to preventive strategies and the prevalence of myopia (up to 1-year YMVIP exposure, odds ratio, 0.86 [95% CI, 0.74-0.99]; up to 2-year YMVIP exposure, odds ratio, 0.56 [95% CI, 0.50-0.63]) after controlling other myopigenic factors.

CONCLUSIONS

This population-based evidence showed high prevalence of preschool myopia and an L-shaped decline after introducing strategies to promote outdoor activities in kindergartens. With undisrupted school-based preventive strategies, the prevalence of myopia can be kept stable, even during the COVID-19 pandemic.

Economic and educational factors played roles in the development of regional vision impairment in Shandong province, China

We analyze regional factors and spatial distribution of children's vision impairment in Shandong province, to explore the spatial changes brought by time and their influencing factors, so as to provide scientific basis for prevention of childhood vision impairment. This study covers five complete cross-sectional surveys from 2013 to 2017, involving about 29.24 million students. Spatial autocorrelation and hotspot analysis methods were used to analyze spatial features. The associated factors were analyzed by multinomial logistic regression. The vision impairment prevalence showed a trend of decreasing first and then increasing from 2013 to 2017, with slight changes. In terms of regional spatial differences, Weihai and Yantai have the highest VI rates in all years, and there was a large-scale spatial aggregation phenomenon. The southern low-value clusters, however, showed a trend of weakening from year to year. Further exploration revealed that economic factors and number of full-time teachers were verified as risk factors for regional vision impairment levels. The slight rebound of the prevalence of vision impairment and the high rate in the eastern and northern regions of Shandong province need more attention. It is suggested that relevant departments should focus on the influence of regional economic and educational factors when formulating relevant strategies.

Myopia Progression as a Function of Sex, Age, and Ethnicity

Purpose

To model juvenile-onset myopia progression as a function of race/ethnicity, age, sex, parental history of myopia, and time spent reading or in outdoor/sports activity.

Methods

Subjects were 594 children in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study with at least three study visits: one visit with a spherical equivalent (SPHEQ) less myopic/more hyperopic than −0.75 diopter (D), the first visit with a SPHEQ of −0.75 D or more myopia (onset visit), and another after myopia onset. Myopia progression from the time of onset was modeled using cubic models as a function of age, race/ethnicity, and other covariates.

Results

Younger children had faster progression of myopia; for example, the model-estimated 3-year progression in an Asian American child was −1.93 D when onset was at age 7 years compared with −1.43 D when onset was at age 10 years. Annual progression for girls was 0.093 D faster than for boys. Asian American children experienced statistically significantly faster myopia progression compared with Hispanic (estimated 3-year difference of −0.46 D), Black children (−0.88 D), and Native American children (−0.48 D), but with similar progression compared with White children (−0.19 D). Parental history of myopia, time spent reading, and time spent in outdoor/sports activity were not statistically significant factors in multivariate models.

Conclusions

Younger age, female sex, and racial/ethnic group were the factors associated with faster myopic progression. This multivariate model can facilitate the planning of clinical trials for myopia control interventions by informing the prediction of myopia progression rates.