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

Associations of incident myopia and its development with related factors among school-aged children across different grades: a four-year longitudinal study

OBJECTIVE

To assess the progression of myopia across different academic grades and investigate the associations between potential myopia-related factors and the incidence of myopia at various grade levels.

METHODS

We utilized data from an ongoing longitudinal study that began with grade 1 students across 12 schools. Four waves of annual eye examinations and questionnaire surveys were conducted. Longitudinal analyses were performed on three groups: Group 1 (n = 1223, non-myopic in grade 1) examined factors in grade 1 associated with incident myopia in grade 2; Group 2 (n = 653, non-myopic in grade 2) investigated factors in grade 2 related to incident myopia in grade 3; and Group 3 (n = 746, non-myopic in grade 3) evaluated factors in grade 3 associated with incident myopia in grade 4.

RESULTS

The incidence of myopia increased from 4.3% in grade 2 to 21.6% in grade 4. Our findings revealed a consistent positive association between the number of myopic parents and incident myopia in grades 2, 3, and 4, respectively. Outdoor activity in earlier grades showed significant protective effects, reducing the risk of incident myopia in the subsequent grades 2 and 3 (e.g., in Group 1, adjusted HR 0.46 [95% CI 0.24 ~ 0.86]). However, no significant association was observed between outdoor activity in grade 3 and incident myopia in grade 4.

CONCLUSIONS

It is important to consider the grade level of schoolchildren when addressing myopia control. Implementing early-phase interventions, particularly those emphasizing outdoor activities, may help mitigate the onset and progression of myopia during the earlier school years.

Chinese parents' knowledge, attitude, and practice of myopia control: 2023 update

BACKGROUND

Our previous survey identified a lack of knowledge of myopia among Chinese parents. This research aims to update the characteristics of parents' knowledge, attitude, and practice in myopia control.

METHODS

A self-administered questionnaire was disseminated to parents of myopic children in 16 hospitals from 11 provinces in China. Comprehensive information regarding the knowledge, attitude, and practice in myopia of parents with myopic children was collected, with the underlying correlations being analyzed.

RESULTS

A total of 1266 valid questionnaires were collected. The concern over children's visual problems arose significantly earlier among myopic parents (P < 0.001). Axial length was recorded by 29.9% (378/1266) of the participants. Parents' primary goal of myopia control was "retarding the progression of myopia" (64.8%, 821/1266). The effectiveness of behavioral intervention was ranked first by 68.4% (866/1266) of the participants. Single-vision spectacles were the most adopted correction practice (26.1%, 331/1266). In terms of myopic interventions, 23.5% (297/1266) of the parents chose myopic control spectacles, followed by orthokeratology (20.9%, 264/1266); 37.3% (189/507) of the participants believed that the latter was more effective. Most parents (69.8%, 883/1266) expressed satisfaction with the current efficacy of myopia control.

CONCLUSION

Insufficient awareness of myopia and myopia control was identified among parents of myopic children in China. Efforts should be made to enhance parents' knowledge, raise their awareness, and improve the accessibility and affordability of effective myopia control interventions.

Comparison of myopia-related behaviors among Chinese school-aged children and associations with parental awareness of myopia control: a population-based, cross-sectional study

Background

In China, approximately 30 and 70% of primary and middle school students, respectively, have myopia, making myopia prevention and control necessary. Eye-use behaviors are closely related to myopia, highlighting the importance of determining the behavioral compliance rates of children. Parental awareness also affects children's behaviors. Therefore, we assessed the myopia-related behaviors and parental awareness of school-aged children in different city tiers of China with different refractive statuses.

Methods

A population-based, cross-sectional study was conducted on Chinese children from 110 cities aged 7-15 years. Samples were equally allocated to each subgroup of city tiers, children's age groups, and children's refractive statuses. Questionnaires were designed to investigate children's behaviors, including responses to sitting position, time of eye use (single continuous near work time and breaks in between, total near work time after school each day), eye rest (break time and style during near work and outdoor time per week), light conditions in the learning environment at home, and parents' knowledge about myopia prevention and control. Associations between parental awareness and children's behaviors were analyzed using logistic regression.

Results

In total, 896 questionnaires were collected. The prevalence of children's poor behaviors related to myopia ranged from 23.44 to 84.82%, with the highest and lowest being sitting position and the use of eye-protecting lamps, respectively. Children in third-tier cities were more likely to have poor sitting position (p < 0.01), a non-open view in front of a desk at home (p = 0.02), and more near activities during break times (p = 0.04). After adjustment for parental myopia condition and the child's sex, poor parental awareness was mainly associated with not using an eye-protecting lamp (odds ratio [OR]: 1.95, 95% confidence interval [CI]: 1.40-2.72), poor break styles (OR: 1.60, 95% CI: 1.21-2.12), and excessive total near work time (OR: 1.45, 95% CI: 1.02-2.05).

Conclusion

Myopia-related behaviors were poorly performed in children, particularly among older children and those living in third-tier cities. Eye-protecting lamps, time spent doing near work, and break style were all associated with parental awareness, suggesting that better parental awareness helps children in the long run. More targeted measures could be adopted to help improve children's behaviors.

Trends in prevalence and disability-adjusted life years for refractive disorders in China and globally from 1990 to 2021: an analysis of the Global Burden of Disease Study 2021

Objectives

This study aimed to describe the temporal trends in the prevalence and disability-adjusted life years (DALYs) of refractive disorders (RD) in China and globally from 1990 to 2021 and provide predictions in China for the next decade.

Methods

Utilizing open data from the Global Burden of Disease database (2021), this study conducted a comprehensive comparative analysis of the RD burden in China and globally, including changes in prevalence and DALYs. Joinpoint regression was employed to calculate the annual percentage change, the average annual percentage change, and its corresponding 95% confidence interval to reflect segmented trends in RD burden. The APC model was used to assess the net effects of age, period, and cohort. The ARIMA model was applied to predict future trends.

Results

The temporal trend of the health burden of RD in China aligned with the global trend, though the magnitude of change was greater, and the gap between the two had been narrowing recently. In China, the age-standardized DALYs rate for the total population (per 100,000 population) decreased from 74 in 1990 to 66 in 2021 and was projected to fall to 29.43 by 2031. The age-standardized prevalence rate for the total population (per 100,000 population) was expected to decrease to 411.23 by 2031, down from 1568 in 1990 to 1468 in 2021. However, the number of cases and the crude rates of prevalence and DALYs exhibited upward trends. In terms of age-specific rates, older adults exhibited higher prevalence and DALYs rates than younger adults. Regarding gender stratification, females had higher prevalence and DALYs rates than males.

Conclusion

The age-standardized rates of prevalence and DALYs for RD have decreased in recent years and may continue to decline over the next decade. However, the crude rates of prevalence and DALYs are on the rise. The health burden of RD remains substantial, with females and the older population bearing a higher burden than males and younger populations.

Efficacy of Asymmetric Myopic Peripheral Defocus Lenses in Spanish Children: 24-Month Randomized Clinical Trial Results

Background/Objectives: Asymmetric myopic peripheral defocus lenses (MPDLs) have proven to be effective in slowing the progression of myopia in Spanish children over a period of 12 months. The purpose of this study was to assess the MPDL spectacles' efficacy in slowing myopia progression over a 24-month period in children. Methods: This study extends the follow-up period of the double-masked, prospective, and randomized clinical trial previously published to 24 months. Children from 6 to 12 years were assigned to two groups: a control group wearing spherotorical single vision lenses (SVLs) or a treatment group wearing MPDL lenses. Inclusion criteria included children with myopia less than -0.50 D, astigmatism below 1.50 D, and best-corrected visual acuity of at least 20/20. Participants underwent cycloplegic autorefractive examination and axial length (AL) measurements at the baseline and six and twelve months in the study already published, and twenty-four months later in the present study. Lifestyle factors, including outdoor activities and digital device use, were also assessed. Baseline characteristics, including age, refractive error, and AL, were comparable between groups. Dropout rates were 15.9%, with 14 participants lost to follow-up, distributed equally between the two groups. Results: After 24 months of follow-up, 69 children remained in this study, comprising 34 participants in the SVL cohort and 35 in the MPDL cohort. Over 24 months, the MPDL group showed significantly less AL elongation than the SVL group (0.27 ± 0.23 mm and 0.37 ± 0.24 mm; p = 0.0341). The mean relative AL increase was 1.10 ± 0.95% in the MPDL group, compared to 1.56 ± 1.02% in the SVL group (p = 0.0322). Younger children exhibited faster AL growth, while digital device use and outdoor activities did not affect AL changes. Conclusions: MPDL spectacle lenses substantially slowed myopia progression over a 24-month period, with 28.7% less progression in absolute AL growth and 29.8% in relative AL growth compared to SVL. These results indicate that MPDL lenses are an effective method for slowing myopia progression.

Advances in myopia control strategies for children

Myopia has long been a global threat to public health. Timely interventions are likely to reduce the risk of vision-threatening complications. There are both established and rapidly evolving therapeutic approaches to slow myopia progression and/or delay its onset. The effective methods for slowing myopia progression include atropine eye-drops, defocus incorporated multiple segments (DIMS) spectacle lenses, spectacle lenses with highly aspherical lenslets target (HALT), diffusion optics technology (DOT) spectacle lenses, red light therapy (RLT), multifocal soft contact lenses and orthokeratology. Among these, 0.05% atropine, HALT lenses, RLT and +3.00 peripheral addition soft contact lenses yield over 60% reduction in myopia progression, whereas DIMS, DOT and MiSight contact lenses demonstrate at least 50% myopia control efficacy. 0.05% atropine demonstrates a more optimal balance of efficacy and safety than 0.01%. The efficacy of 0.01% atropine has not been consistent and requires further validation across diverse ethnicities. Combining atropine 0.01% with orthokeratology or DIMS spectacles yields better outcomes than using these interventions as monotherapies. Increased outdoor time is an effective public health strategy for myopia prevention while recent studies suggest that 0.05% low-concentration atropine and RLT therapy have promising potential as clinical myopia prevention interventions for high-risk groups. Myopia control spectacle lenses, being the least invasive, are safe for long-term use. However, when considering other approaches, it is essential to ensure proper instruction and regular follow-ups to maintain safety and monitor any potential complications. Ultimately, significant advances have been made in myopia control strategies, many of which have shown meaningful clinical outcomes. However, regular use and adequate safety monitoring over extended durations are imperative to foster confidence that can only come from extensive clinical experience.

Lower indoor spatial frequency increases the risk of myopia in children

BACKGROUND/AIMS

Animal models have shown that the absence of high-frequency visual information can precipitate the onset of myopia, but this relationship remains unclear in humans. This study aims to explore the association between the spatial frequency content of the visual environment and myopia in children.

METHODS

Images from the rooms of children and their frequently visited outdoor areas were taken by their parents and collected by the researcher through questionnaires. The spatial frequency was quantified using Matlab. Cycloplegic refraction was used to measure the spherical equivalent (SE), and IOL Master was used to measure axial length (AL) and corneal radius (CR). AL/CR ratio was calculated.

RESULTS

The study included 566 children with an average age of (8.04±1.47) years, of which 270 were girls (47.7%), and the average SE was (0.70±1.21) D. Image analysis revealed that indoor spatial frequency slope was lower than that of the outdoor environment (-1.43±0.18 vs -1.11±0.23, p<0.001). There were 79 myopic individuals (14.0%). Images from indoor content of myopic children had a lower spatial frequency slope than non-myopic children (-1.47±0.16 vs 1.43±0.18, p=0.03) while there was no significant difference in outdoor spatial frequency slope. Regression analysis indicated that the indoor spatial frequency slope was positively associated with SE value (β=0.60, p=0.02) and inversely related to myopia (OR=0.24, p<0.05).

CONCLUSION

The spatial frequency of the outdoor environment is significantly higher than that of the indoor environment. Indoor spatial frequency is related to children's refractive status, with lower indoor spatial frequency being associated with a higher degree of myopia.

Evaluation of the perception of information from ChatGPT in myopia education: Perspectives of students and professionals

PURPOSE

The purpose of this study was to compare the perception and understanding of the information provided by ChatGPT regarding myopia among optometry students, optometrists undertaking a Master degree and practicing optometrists.

METHODS

This was a cross-sectional descriptive study using a structured questionnaire distributed via Wooclap to 225 participants (125 optometry students, 21 Masters students and 79 practicing optometrists). All participants evaluated the responses generated by ChatGPT Version 4.0 using a five-point scale: very poor, poor, acceptable, good and very good. Data were analysed using SPSS, applying descriptive analysis and chi-squared tests to assess the significance of differences observed between the groups.

RESULTS

Practicing optometrists, with an average age of 39.7 ± 11.0 and 15.2 ± 7.5 years of professional experience, rated the information provided by ChatGPT on myopia complications more positively than the optometry and Masters students, highlighting the importance of clinical experience (p < 0.001). Alternatively, this may indicate a difference in awareness, knowledge and training, with younger students potentially being more speculative in their evaluations. The perceptions about myopia prevention among the groups were similar (p = 0.28). At the same time, the perceptions of the effectiveness of treatments such as contact lenses and pharmaceutical agents showed differences, with optometrists rating these treatments more positively (p < 0.001 and p = 0.004, respectively).

CONCLUSIONS

This study showed differences in the perception and interpretation of the information provided by ChatGPT about myopia depending on the level of education. While AI plays an important role in education, practicing optometrists trust the information extracted by ChatGPT more than optometry students.

Measuring the visual environment of children and young people at risk of myopia: a scoping review

PURPOSE

Myopia (short-sightedness) is an emerging WHO priority eye disease. Rise in prevalence and severity are driven by changes in lifestyle and environment of children and young people (CYP), including less time spent in bright daylight and more time spent on near-vision activities. We aimed to systematically map the literature describing direct, objective measurements of the visual environment of CYP.

METHODS

We conducted searches in Ovid Medline 1946, Ovid Embase and The Cochrane Central Register of Controlled Trials in November 2024. We included primary research written in English on environmental/behavioural factors and myopia onset/progression in CYP 3-18 years. Two reviewers independently screened titles/abstracts/full texts.

RESULTS

We included 34 articles: 21 explored the association of indoor and/or outdoor light exposure and myopia and included light measurements, two near-vision activities, four both light and near-work, four time outdoors without illuminance measurements, and three light exposure based on meteorological data. Most measurements were carried out at the level of individual children, rather than the surrounding environment alone.

CONCLUSION

Despite limitations in measurement techniques, there is evidence that reduced illuminance, less time spent in bright light and increased daily duration/sustained episodes of near-vision activities and reduced working distance are associated with increased myopia prevalence/progression.

Cross-population validation of the PreMO risk indicator for predicting myopia onset in children

PURPOSE

The Predicting Myopia Onset and progression (PreMO) risk indicator, developed using data generated from white children in the UK, incorporates age, spherical equivalent refraction (SER), axial length (AL) and parental myopia to stratify the likelihood of developing myopia. This study evaluated the PreMO's predictive accuracy using prospective datasets from independent samples of children in Hong Kong (HK) and an ethnically diverse cohort of children in the United Kingdom.

METHODS

Non-myopic children (SER > -0.50 D) aged 6-8 and 9-10 years were scored using the PreMO risk indicator framework, integrating baseline cycloplegic SER, AL and parental myopia data. Scores were assigned risk categories as follows: 0 = no risk, 1-3 = low risk, 4-6 = moderate risk and 7-9 = high risk. SER at ≥15 years of age was used to define refractive outcomes as 'myopic' or 'not myopic'. PreMO's predictive accuracy was analysed via Receiver Operator Characteristic curves, with Youden's J-Index identifying the optimal risk score threshold. Sensitivity, specificity and area under the curve were determined and compared with those of singular predictors, that is, SER < +0.75 D and AL ≥ 23.07 mm at 6-8 years.

RESULTS

In the cohort of children aged 6-8 years, a PreMO risk score ≥ 4 exhibited high sensitivity in predicting myopia onset in UK (0.97) and HK (0.94) children, with high specificity in UK (0.96) and moderate specificity in HK (0.64) children. In UK children aged 6-8 years, the PreMO outperformed singular predictors such as SER and AL. Among HK children aged 9-10 years, the PreMO score maintained high sensitivity (0.90) and moderate specificity (0.72).

CONCLUSIONS

A PreMO risk score ≥ 4 is a strong predictive indicator for future myopia onset, particularly in UK children. Despite high sensitivity in both UK and HK cohorts, specificity varied, indicating the need for contextual application of the tool, particularly in pre-myopic Asian children.

Recent Advances in Ophthalmic Interventions: Exploring Innovations in Myopia, Cataract Surgery, and Visual Function

As our understanding of ophthalmic optics and visual function advances, the intersection between clinical practice and technological innovation becomes increasingly significant in enhancing patient outcomes [...].

Outdoor activity during class recess prevents myopia onset and shift in premyopic children: Subgroup analysis in the recess outside classroom study

PURPOSE

To investigate whether premyopia is a risk factor for myopia onset and whether outdoor activities can protect against myopia development in premyopic children in the Recess Outside Classroom (ROC) study.

METHODS

Nonmyopic schoolchildren aged 7-11 years were recruited from two schools in Taiwan. One school implemented the ROC program, which encouraged children to go outdoors during recess. The control school maintained its usual schedule. A cycloplegic autorefraction was performed. Premyopia was defined as spherical equivalent refraction ≤ +0.75 diopters (D) and > -0.50 D.

RESULTS

After one year of follow-up, multivariate logistic analysis revealed that the ROC program reduced the risk of myopia onset by 61 % (odds ratio [OR] = 0.39, 95 % confidence interval [CI]: 0.21-0.70, P = 0.002). However, premyopia status increased the risk of myopia onset by 14 times compared to hyperopic status (OR = 14.0, 95 % CI: 1.86-105.3, P = 0.010). In the subgroup analysis of premyopic children, the myopic shift was also significantly lower in the ROC group than in the control group (-0.20 ± 0.60 D/year vs. -0.40 ± 0.66 D/year, P = 0.017). Myopia incidence in premyopic children was significantly lower in the ROC group than in the control group (19.6 % vs. 37.8 %, P = 0.001). Multivariate regression analysis showed that participation in the ROC program was significantly associated with a lower myopic shift in premyopic children (-0.22 D/year, 95 % CI: -0.39 to -0.06, P = 0.008) CONCLUSIONS: Premyopia is a risk factor for myopia onset. A school policy that includes more outdoor time can effectively prevent myopia onset and shift in premyopic children.

Myopia control strategies: A systematic review and meta-meta-analysis

PURPOSE

To summarise pooled estimates of the efficacies of various myopia control interventions, as drawn from published meta-analyses.

METHOD

PubMed, SCOPUS and Web of Science were searched from inception to February 2024 for systematic reviews and meta-analyses reporting treatment effects of various myopia control strategies. The qualities of the included meta-analyses were assessed using the 16-item A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2. An intervention was defined as having a clinically significant effect if it resulted in a change in spherical equivalent refraction (SER) of ≥0.50 D/year or axial length (AL) change of ≤-0.18 mm/year.

RESULTS

A total of 38 studies were identified. The overall respective changes in SER and AL, mean difference (95% CI) were high-concentration (≥0.5%) atropine 0.67 D (0.58-0.77) and -0.24 mm (-0.36 to -0.11); moderate-concentration (>0.05% to <0.5%) atropine 0.48 D (0.34-0.62) and -0.23 mm (-0.27 to -0.19); low-concentration (0.01%, 0.025%, 0.05%) atropine 0.33 D (0.23-0.43) and -0.14 mm (-0.19 to -0.09); orthokeratology -0.47 mm (-0.66 to -0.28); peripheral plus soft contact lenses 0.30 D (0.18-0.42) and -0.35 mm (-0.62 to -0.08); peripheral plus spectacles 0.77 D (0.40-1.14) and -0.43 mm (-0.78 to -0.08); multifocal spectacles 0.21 D (0.11-0.31); repeated low-level red light therapy 0.55 D (0.46-0.65) and -0.25 mm (-0.29 to -0.20); outdoor time 0.17 D (0.16-0.18) and -0.04 mm (-0.06 to -0.01).

CONCLUSION

High and moderate concentrations of atropine, orthokeratology, peripheral plus spectacles and repeated low-level red light demonstrated clinically significant effects on slowing AL elongation, while high and moderate concentrations of atropine, peripheral plus spectacles and repeated low-level red light demonstrated clinically significant effects on slowing SER progression.

Efficacy of defocus incorporated multiple segments (DIMS) lenses and low-dose atropine on retarding myopic shift among premyopic preschoolers: Protocol for a prospective, multicenter, randomized controlled trial

BACKGROUND

Myopia has been a rising problem globally. Early-onset myopia significantly increases the risk of high myopia later in life. Despite the proven benefits of increased outdoor time, optimal strategies for preventing early-onset myopia in premyopic children need further investigation.

METHODS

This randomized controlled trial aims to evaluate the efficacy of optical (Defocus Incorporated Multiple Segments [DIMS] spectacle lenses) and pharmacological (0.01% atropine eye drops) interventions in preventing myopia among premyopic preschoolers. We will recruit 234 premyopic, asymptomatic 5-to-6-year-old children who will have received cycloplegic autorefraction examination in a countywide kindergarten eye care program in Yilan County, Taiwan. Eligible participants will be randomly assigned to DIMS spectacles (n = 78), 0.01% atropine (n = 78), or usual care (n = 78). In the DIMS group, preschoolers will be instructed to wear spectacles at home before entering elementary school but to wear them all the time after school entry. In the atropine group, subjects will be given 0.01% atropine eyedrops nightly throughout the study period. All participants will be encouraged to spend time outdoors for 2 hours every day. During the 18-month study period, cycloplegic spherical equivalent (SE) refraction, axial length, and subfoveal choroidal thickness will be measured every three months, and parents-administered questionnaires regarding risk factors for myopia will be performed every nine months.

PRIMARY OUTCOME

The change in mean cycloplegic SE.

SECONDARY OUTCOMES

The cumulative percentage of incident myopia, the cumulative percentage of a fast myopic shift of SE, and the changes in mean axial length.

OTHER PRE-SPECIFIED OUTCOMES

The time to myopia onset, alteration in subfoveal choroidal thickness, and levels of near work/outdoor activities.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov as NCT06200194.

CONCLUSION

This trial will provide insights into myopia prevention strategies and inform new eye care policies for early identification and intervention in premyopic preschoolers.

Short-term effects of sunlight exposure on fundus blood flow perfusion in children: a randomised controlled trial

AIM

To evaluate the short-term effects of different sunlight exposure on fundus blood flow perfusion (BFP) after near work.

METHODS

In this parallel randomised controlled trial, 81 students aged 7-15 with spherical equivalent refraction between -2.00 and +3.00 diopters were randomly assigned to either a low-illuminance (4k lux) group (N=40) or high-illuminance (10k lux) (N=41). Following 1 hour indoor reading, participants had sunlight exposure matching their group's intensity for 15 minutes. BFPs in the superficial retina, deep retina and choroid were measured at four time points: pre-reading, post-reading, 5th-minute and 15th-minute sunlight exposure.

RESULTS

Within the initial 5 minutes of sunlight exposure, the 10k lux group showed a tendency for decreased BFP, particularly in the choroid (superficial retina: -0.2, 95% CI -0.9 to 0.5; deep retina: -0.1, 95% CI -0.6 to 0.4; choroid: -0.4, 95% CI -0.8 to 0.0), while the 4k lux group exhibited an increase (superficial retina: 0.7, 95% CI 0.1 to 1.3; deep retina: 0.3, 95% CI -0.2 to 0.8; choroid: 0.1, 95% CI -0.2 to 0.5). From 5 to 15 minutes, BFP decreased in both groups. At the 5th-minute mark, the 10k lux group exhibited a greater decrease in choroid (10k -0.4 vs 4k 0.1, p=0.051). No significant difference was observed after 15 minutes of exposure.

CONCLUSION

Higher illuminance sunlight exposure can restore fundus BFP more rapidly than lower; however, duration remains pivotal. To prevent myopia, continuous sunlight exposure for over 15 minutes is recommended to aid in reinstating the fundus BFP increased by near work.

TRIAL REGISTRATION NUMBER

NCT05594732.

Evaluating the Effectiveness and Scalability of the World Health Organization MyopiaEd Digital Intervention: Mixed Methods Study

BACKGROUND

The rapid rise of myopia worldwide, particularly in East and Southeast Asia, has implied environmental influences beyond genetics. To address this growing public health concern, the World Health Organization and International Telecommunication Union launched the MyopiaEd program. South Korea, with its high rates of myopia and smartphone use, presented a suitable context for implementing and evaluating the MyopiaEd program.

OBJECTIVE

This is the first study to date to evaluate the effectiveness and scalability of the MyopiaEd program in promoting eye health behavior change among parents of children in South Korea.

METHODS

Parents of children aged 7 and 8 years were recruited through an open-access website with a recruitment notice distributed to public elementary schools in Gwangju Metropolitan City. Beginning in September 2022, parents received 42 SMS text messages from the MyopiaEd program over 6 months. This digital trial used a mixed methods approach combining both quantitative and qualitative data collection. Pre- and postintervention surveys were used to assess changes in parental knowledge and behavior regarding myopia prevention. Additionally, semistructured interviews were conducted to explore participants' experiences in depth and receive feedback on program design. Prior to the intervention, the MyopiaEd program design and message libraries were adapted for the Korean context following World Health Organization and International Telecommunication Union guidelines.

RESULTS

A total of 133 parents participated in this study, including 60 parents whose children had myopia and 73 parents whose children did not. Both groups reported high engagement and satisfaction with the program. Significant increases in knowledge about myopia were observed in both groups (P<.001). While time spent on near-work activities did not change significantly, parents of children with myopia reported increased outdoor time for their children (P=.048). A substantial increase in eye checkups was observed, with 52 (86.7%) out of 60 children with myopia and 50 (68.5%) out of 73 children without myopia receiving eye examinations following the intervention. Qualitative analysis indicated a shift in parents' attitudes toward outdoor activities, as increased recognition of their benefits prompted positive changes in behavior. However, reducing near-work activities posed challenges due to children's preference for smartphone use during leisure periods and the demands of after-school academies. The credibility of the institution delivering the program enhanced parental engagement and children's adoption of healthy behaviors. Messages that corrected common misconceptions about eye health and provided specific behavioral guidance were regarded as impactful elements of the program.

CONCLUSIONS

This study demonstrates the MyopiaEd program's potential as a scalable and innovative digital intervention to reduce myopia risk in children. The program's effectiveness provides support for broader adoption and offers valuable insights to inform future myopia prevention policies.

Modulation of all- trans retinoic acid by light and dopamine in the murine eye

Purpose

Ambient light exposure is linked to myopia development in children and affects myopia susceptibility in animal models. Currently, it is unclear which signals mediate the effects of light on myopia. All- trans retinoic acid (atRA) and dopamine (DA) oppositely influence experimental myopia and may be involved in the retino-scleral signaling cascade underlying myopic eye growth. However, how ocular atRA responds to different lighting and whether atRA and DA interact remains unknown.

Methods

Dark-adapted C57BL/6J mice (29-31 days old) were exposed to Dim (1 lux), Mid (59 lux), or Bright (12,000 lux) ambient lighting for 5-60 minutes. Some mice were also systemically administered the DA precursor, LDOPA, or atRA prior to light exposure. After exposure, the retina and the back-of-the-eye (BOE) were collected and analyzed for levels of atRA, DA, and the DA metabolite, DOPAC.

Results

DA turnover (DOPAC/DA ratio) in the retina increased in magnitude after only five minutes of exposure to higher ambient luminance but was minimal in the BOE. In contrast, atRA levels in the retina and BOE significantly decreased with higher ambient luminance and longer duration exposure. Intriguingly, LDOPA-treated mice had a transient reduction in retinal atRA compared to saline-treated mice, whereas atRA treatment had no effect on ocular DA.

Conclusions

Ocular atRA was affected by the duration of exposure to different ambient lighting and retinal atRA levels decreased with increased DA. Overall, these data suggest specific interactions between ambient lighting, atRA, and DA that could have implications for the retino-scleral signaling cascade underlying myopic eye growth.

A generalized additive model analysis of school classroom environment and students' refractive state progression

BACKGROUND

The study, undertaken in Fengxian District, Shanghai, seeks to investigate the correlation between the sanitary conditions of high school classrooms and the changes in students' uncorrected visual acuity and refractive status, given their predominantly classroom-centric lifestyle and the considerable academic pressures they encounter.

METHODS

Utilizing a cluster random sampling approach, we randomly selected 48 classrooms for monitoring from 8 high schools within the jurisdiction, taking into account factors such as classroom orientation and floor level. A cohort comprising 1087 students was enrolled and followed for a year, with their refractive data being collected. A generalized additive model was employed to examine the associations between classroom environmental factors and students' visual acuity as well as refractive status.

RESULTS

Significant increases were observed in the spherical equivalent, cylinder, and corneal astigmatism for both the right and left eyes from 2022 to 2023 (P < 0.001). However, no significant change was noted in uncorrected visual acuity (P > 0.05). The compliance rate for blackboard size (height) was 100%, with an average of (1.16 ± 0.06) m and a minimum of 1.06 m. None of the classrooms met the standards for the distance between the multimedia display and the front seat, with an average of (177.26 ± 17.78) m. Classroom per capita area, blackboard size (height), and the distance between the multimedia display and the front seat influenced changes in uncorrected visual acuity. Additionally, classroom per capita area affected changes in the spherical equivalent. The window-to-ground area ratio and blackboard reflectance ratio impacted changes in astigmatism values at 90°-180° (J180) and 45°-135° (J45). Blackboard size (width) and the window-to-ground area ratio influenced changes in students' corneal astigmatism. The classroom with the least impact on refractive status had a per capita area of 1.6 m2, a blackboard size (width) of approximately 4.2 m, and a window-to-floor area ratio of around 0.27.

CONCLUSIONS

Schools should adhere to national standards to enhance the classroom visual environment and further improve the compliance rate.

Estimating the True Effect of Lifestyle Risk Factors for Myopia: A Longitudinal Study of UK Children

Purpose

Lifestyle risk factors are implicated in driving the current surge in myopia prevalence yet, paradoxically, known risk factors explain little of the variation in refractive error in the population. Here, we applied "instrumental variable" (IV) methods designed to avoid reverse causation and decrease confounding bias, to gauge lifestyle risk factor effect sizes.

Methods

Three myopia risk factors (time outdoors, time reading, and sleep duration) were assessed in participants of the Avon Longitudinal Study of Parents and Children: a cross-sectional sample of 2302 children aged 15 years old and a longitudinal sample of 3086 children followed from age 7 to 15 years. Seven IVs were considered jointly: dog ownership, cat ownership, bedtime variability, birth order, and polygenic scores quantifying genetic predisposition to spend additional time outdoors, years in fulltime education, and time asleep overnight.

Results

Risk factor effect sizes were 4-fold to 9-fold higher in the IV analyses compared with conventional regression analyses. In IV analyses, one extra hour spent outdoors every day during childhood was associated with a shift toward hyperopia of +0.53 to +0.94 diopters (D), whereas 1 extra hour spent reading every day was associated with a shift toward myopia of -0.44 to -0.88 D. There was inconsistent evidence that sleep duration influenced refractive error.

Conclusions

Myopia risk factor effects were underestimated up to 9-fold in conventional analyses in this sample, compared with IV analyses.

Translational Relevance

We speculate that the effects of lifestyle risk factors for myopia have been underestimated in past studies.

Effects of wearing myopia glasses on eye movement and scleral blood supply

The present study examined the effect of wearing myopia glasses on eye movement and scleral blood supply. For this purpose, a total of 30 individuals were recruited for the present self-control study. Under the same fixation distance, the individuals wore 0.00 D and -10.00 D glasses. The amount of eye movement generated when shifting from gazing at a central point to a point light source located at the left or right was measured and compared between the two glasses. The results revealed that the range of eye movement was significantly reduced after wearing -10.00 D glasses. When gazing at the right point light source from the central point, the difference between the rotation distances of the right eye when wearing the 0.00 D glasses and the -10.0 D glasses was 0.73±0.45 mm (t=8.93, P<0.01) and that of the left eye was 0.73±0.43 mm (t=9.34, P<0.01). Similar results were obtained when the left point light source was viewed from a shift in gaze from the central point. On the whole, the present study demonstrates that wearing concave lenses limits eyeball movement. Restricted eyeball movement can affect vascular changes within the extraocular muscles and blood flow, thereby affecting the blood supply to the anterior segment and sclera of the eye, potentially accelerating the development of myopia.

Low-concentration atropine for controlling myopia onset and progression in East Asia

PURPOSE

Over the past few years, there has been a rapid accumulation of data on the use of low-concentration atropine for myopia control, especially in East Asian children, with its effectiveness varying in different studies. This review aims to evaluate the current evidence surrounding the efficacy and safety of low-concentration atropine in the management of myopia onset and progression in East Asia.

METHODS

Clinical trials involving atropine for myopia control in East Asia were reviewed.

RESULTS

Atropine has been shown to reduce myopia progression in East Asian children, compared with placebo. Its efficacy is concentration-dependent, with 1 % atropine yielding the greatest effect in slowing myopia progression by over 70 %, but it is associated with significant rebound and side effects. Lower concentrations also confer significant myopia-control effects while maintaining a more acceptable safety profile, with relative reductions of 67 % and 43 % reported for 0.05 % and 0.025 % atropine, respectively. While 0.01 % atropine showed the least effect compared to 0.05 % and 0.025 %, it still yielded a significant efficacy in slowing myopic refraction. Over two years, 0.05 % atropine reduced the incidence of myopia by nearly 50 %, demonstrating greater effectiveness than 0.01 % atropine. This effect was particularly notable in children with low hyperopic reserves (< +0.75 D), but not in those with higher reserves.

CONCLUSIONS

The current evidence shows that low-concentration atropine plays a crucial role in managing myopia in East Asian children and demonstrates satisfactory safety profiles. Timely administration of the most effective and safest concentration can potentially prevent sight-threatening complications and subsequent vision loss.

Prevalence and risk factors of myopia among children and adolescents in Hangzhou

To analyze the prevalence and influencing factors of myopia among children and adolescents in Hangzhou city, and provide ideas for the formulation of myopia prevention and control measures. A cross-sectional school-based study using stratified cluster random sampling method was used to select 31,880 students from 113 schools in Hangzhou city. Myopia screening and questionnaires on the influencing factors of poor visual acuity were carried out. Univariate and multivariate logistic regression were used to screen possible risk factors of myopia. The overall prevalence of myopia was found to be 55.3% (17,630/31,880), with the myopia rates observed among students in kindergarten, primary school, junior high school, and senior high school, at 5.8%, 34.9%, 74.2%, and 85.0%, respectively. As the academic year progresses, there has been an observable increase in the prevalence of myopia (χ2 = 8676.748, P<0.001), low myopia (χ2 = 5444.040, P<0.001) and high myopia (χ2 = 2171.073, P<0.001) among students, with the difference between the three groups being statistically significant. The myopia prevalence in girls is higher than that in boys (χ2 = 119.917, P<0.001); the prevalence of myopia in urban students is higher than that in suburban students (χ2 = 4.603, P = 0.032). The time spent on homework after school, the correctness of reading and writing postures, the duration of exposure to electronic screens, and the use of lighting in an appropriate manner all have an impact on the development of myopia (all P<0.05). The overall prevalence of myopia and high myopia in schools in eastern China, is notably high. The prevalence of myopia and high myopia increases with grade or age. Myopia is associated with increased age, parental myopia, extended periods of homework after school, poor reading and writing posture, prolonged exposure to electronic screens and inappropriate lighting. In light of the findings of the present survey, it is recommended that a comprehensive prevention and control intervention model for myopia in children and adolescents based on society-hospital-school-family-individual students with a view to preventing and controlling myopia.

Effect of virtual reality-based visual training for myopia control in children: a randomized controlled trial

BACKGROUND

To assess the efficacy and safety of virtual reality-based visual training (VRVT) in myopia control among children.

METHODS

The randomized, parallel-group, single-blind clinical trial conducted at the Department of Ophthalmology of Shanghai Tenth People's Hospital enrolled 65 low-myopic children (aged 8 to 13 years) with cycloplegic spherical equivalent (SE) between - 0.50 and - 3.00 diopters (D), astigmatism less than - 1.00 D, anisometropia less than 1.50D, and best corrected visual acuity (BCVA) more than 0.0 logarithm (LogMAR) of the minimum angle of resolution. The participants were enrolled in December 2020, and the follow-up of this study concluded on August 2021. Children were assigned randomly to the intervention group (VRVT plus single-vision spectacle [SVS]) and the control group (only SVS without receiving VRVT). The intervention group was administered for 20 min per day with VRVT under parental supervision at home. The primary outcome was changes in axial length (AL) at 3 months. Macular choroidal thickness (mCT) was regarded as a key secondary outcome.

RESULTS

Among 65 participants (mean age: 10.8 years, 52.3% male), 60 children (92.3%) who completed the 3-month intervention and 6-month follow-up were included in the analysis (30 in the intervention group and 30 in the control group). The changes of AL were 0.063 ± 0.060 mm (95% confidence interval [CI], 0.074 to 0.119 mm) in the intervention group and 0.129 ± 0.060 mm (95% CI, 0.107 to 0.152 mm) and in the control group at 3 months (t = - 2.135, P = 0.037), and the mean difference between the two groups was 0.066 mm. The change of mCT were 22.633 ± 36.171 μm (95% CI, 9.127 to 36.140 μm) in the intervention group and - 3.000 ± 31.056 μm (95% CI, - 14.597 to 8.597 μm) in the control group at 3 months (t = 2.945, P = 0.005). VR vertigo was the most common adverse event which was occurred in two children (2/30, 6.67%) in the intervention group.

CONCLUSIONS

VRVT is a promising method for myopia control in children with good user acceptability. Among children aged 8 to 13 years with low-myopia, nightly use of VRVT resulted in slowing myopia progression.

TRIAL REGISTRATION

This protocol was registered with ClinicalTrials.gov (NCT06250920), retrospectively registered on 01 February 2024.

Loss of ON-Pathway Function in Mice Lacking Lrit3 Decreases Recovery From Lens-Induced Myopia

Purpose

To determine whether the Lrit3-/- mouse model of complete congenital stationary night blindness with an ON-pathway defect harbors myopic features and whether the genetic defect influences the recovery from lens-induced myopia.

Methods

Retinal levels of dopamine (DA) and 3,4 dihydroxyphenylacetic acid (DOPAC) from adult isolated Lrit3-/- retinas were quantified using ultra performance liquid chromatography after light adaptation. Natural refractive development of Lrit3-/- mice was measured from three weeks to nine weeks of age using an infrared photorefractometer. Susceptibility to myopia induction was assessed using a lens-induced myopia protocol with -25 D lenses placed in front of the right eye of the animals for three weeks; the mean interocular shift was measured with an infrared photorefractometer after two and three weeks of goggling and after one and two weeks after removal of goggles.

Results

Compared to wild-type littermates (Lrit3+/+), both DA and DOPAC were drastically reduced in Lrit3-/- retinas. Natural refractive development was normal but Lrit3-/- mice showed a higher myopic shift and a lower ability to recover from induced myopia.

Conclusions

Our data consolidate the link between ON pathway defect altered dopaminergic signaling and myopia. We document for the first time the role of ON pathway on the recovery from myopia induction.

Mediation effect of sleep time on the association between outdoor activity and myopia in Chinese children and adolescents: a cross-sectional study

BACKGROUND

This study aimed to assess the association between outdoor activity and myopia among children and adolescents and investigate whether sleep time could mediate this relationship.

METHODS

This cross-sectional study was performed on students aged 4-16 years in China, from August 2021 to January 2022. Outdoor activity was assessed by the Assessment Questionnaire of Exposure to Sunlight Activities for Students (AQESAS). Binary logistic regression combined with the mediation analysis was used to analyze the association of AQESAS with myopia and the mediating effect of sleep time on this relationship.

RESULTS

The prevalence of myopia was 53.51% (N = 1609). Multivariate logistic regression analysis showed that more sleep time (OR = 0.794, 95%CI: 0.707-0.893) and a higher score of AQESAS (OR = 0.989, 95%CI: 0.981-0.996) were significantly associated with a decreased risk of myopia. Mediation analysis revealed that sleep time plays a mediating role in the association between outdoor activity and myopia (ACME = -0.0006, P < 0.001), and the mediation proportion was 19.7%.

CONCLUSION

Outdoor activity affects myopia directly and indirectly through sleep time. The result suggested that children may be able to reduce the risk of myopia by promoting sleep through increased awareness of outdoor activity and exposure to sunlight.

Effectiveness of repeated low-level red light in myopia prevention and myopia control

BACKGROUND/AIMS

To compare the effects of repeated low-level red light (RLRL) treatment on axial length growth and refractive error changes in myopic and premyopic children.

METHODS

Subjects were assigned randomly to four subgroups: myopia-RLRL group (M-RL), myopia-control group (M-C), premyopia-RLRL group (PM-RL) and premyopia-control group (PM-C). Subjects in the RLRL group completed a 12-month treatment composed of a 3 min RLRL treatment session twice daily, with an interval of at least 4 hours, for 7 days per week. Visits were scheduled before and at 1-month, 3-month, 6-month, 9-month and 12-month follow-up after the treatment. Repeated-measures analysis of variance was used to compare the spherical equivalent refractive errors (SE) and axial length (AL) changes between the groups across the treatment period.

RESULTS

After 12 months of treatment, in the myopia group, SE and AL changes were -0.078±0.375 D and 0.033±0.123 mm for M-RL and -0.861±0.556 D and 0.415±0.171 mm for M-C; in the premyopia group, the progression of SE and AL was -0.181±0.417 D and 0.145±0.175 mm for PM-RL and -0.521±0.436 D and 0.292±0.128 mm for PM-C. PM-RL indicated a lower myopia incidence than PM-C (2.5% vs 19.4%). Additionally, the percentage of AL shortening in the M-RL was higher than that in the PM-RL before the 9-month follow-up.

CONCLUSION

RLRL effectively delayed myopia progression in children with myopia and reduced the incidence of myopia in premyopic children. Moreover, RLRL exhibited a stronger impact on myopic children compared with premyopic individuals.

Collagen is crucial target protein for scleral remodeling and biomechanical change in myopia progression and control

In recent decades, the prevalence of myopia has been on the rise globally, attributed to changes in living environments and lifestyles. This increase in myopia has become a significant public health concern. High myopia can result in thinning of the sclera and localized ectasia of the posterior sclera, which is the primary risk factor for various eye diseases and significantly impacts patients' quality of life. Therefore, it is essential to explore effective prevention strategies and programs for individuals with myopia. Collagen serves as the principal molecule in the extracellular matrix (ECM) of scleral tissue, consisting of irregular collagen fibrils. Collagen plays a crucial role in myopia progression and control. During the development of myopia, the sclera undergoes a thinning process which is primarily influenced by collagen expression decreased and remodeled, thus leading to a decrease in its biomechanical properties. Improving collagen expression and promoting collagen crosslinking can slow down the progression of myopia. In light of the above, improving collagen expression or enhancing the mechanical properties of collagen fibers via medication or surgery represents a promising approach to control myopia.

Efficacy of outdoor interventions for myopia in children and adolescents: a systematic review and meta-analysis of randomized controlled trials

Objectives

The objective of this systematic review and meta-analysis was to evaluate the overall efficacy of outdoor interventions for myopia in children and adolescents, and to provide evidence for the prevention and control of myopia.

Methods

Randomized controlled trials of outdoor interventions for myopia in children and adolescents were identified using electronic databases and manual searches. The Revised Cochrane risk-of-bias tool for randomized trials (RoB 2) was used to assess risk of bias in randomized controlled trials. A mean difference (MD) and a risk ratio (RR) with a 95% confidence interval (CI) were used to combine effect sizes. A sensitivity analysis was performed for each outcome using a stepwise elimination method to assess whether the pooled results were significantly affected by individual studies.

Results

The analysis included seven randomized controlled trials involving a total of 9,437 subjects. The meta-analysis showed marked and statistically significant improvements in spherical equivalent refraction (MD = 0.19; 95% CI 0.14 to 0.25; p < 0.01), axial length (MD = -0.09; 95% CI -0.13 to -0.05; p < 0.01), and myopia incidence (RR = 0.84; 95% CI 0.78 to 0.91; p < 0.01) following outdoor interventions.

Conclusion

Outdoor interventions effectively contributed to the prevention and control of myopia in children and adolescents, positively impacting spherical equivalent refraction, axial length, and myopia incidence. Outdoor interventions were characterized by low risk and high therapeutic benefits and could serve as alternative or adjuvant approaches to medication for the treatment of myopia. Considering the advantages in terms of safety and efficacy, outdoor interventions may be considered as a preferred intervention for the treatment of myopia in children and adolescents, while susceptibility to diseases associated with sunlight, particularly UV exposure, must be taken into account.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, Identifier CRD42024538695.

Characteristics of Peripheral Retinal Refraction and Its Role in Children with Different Refractive States

Introduction

Peripheral retinal refraction plays a crucial role in myopia, but the specific mechanism is not clear. We refined the retinal partitions to explore the characteristics of peripheral retinal refraction and its role in emmetropic, low, and moderate myopic children aged 6 to 12 years.

Methods

A total of 814 subjects (814 eyes) were enrolled in the study. The participants were divided into three groups according to the central spherical equivalent refraction (SER), which were emmetropia group (E), low myopia group (LM) and moderate myopia group (MM). Multispectral refractive topography (MRT) was used to measure the retinal absolute and relative refractive difference value (RDV) in different regions. The range was divided into superior, inferior, temporal, and nasal RDV (SRDV, IRDV, TRDV, and NRDV) on the basis of several concentric circles extending outward from the macular fovea (RDV15, RDV30, RDV45, RDV30-15, RDV45-30, and RDV-45). Kruskal-Wallis test was used to analyze the differences of peripheral refraction for all the regions among the three groups. Spearman rank correlation was performed to explore correlations between SER and RDV, axial length (AL) and RDV.

Results

The absolute value of RDV decreased with increasing degree of myopia in all regions (P < 0.01). Subjects with different refractive degrees had different relative value of RDV. In nasal position within 45° and temporal position within 30°, the peripheral retina exhibited significantly different relative hyperopic refractive status among Group E, Group LM, and Group MM (P < 0.05). SER was negatively correlated with NRDV within 30° (especially in the range of NRDV30-15) (r = -0.141, P < 0.01), positively correlated with TRDV within 15° (r = 0.080, P = 0.023), and not significantly correlated with SRDV and IRDV when the retina was divided into four parts. AL was positively correlated with NRDV within 30° (especially in the range of NRDV30-15) (r = 0.109, P = 0.002), negatively correlated with TRDV within 15° (r = -0.095, P = 0.007).

Conclusions

The peripheral defocus has significant implications for the genesis of myopia. The peripheral defocus of the horizontal direction, especially within the range of NRDV30, has greater effect on the development of myopia in children. Higher NRDV30 is associated with lower SER and longer AL.

The Onset and Progression of Myopia Slows in Chinese 15-Year-Old Adolescents Following Vocational Rather Than Academic School Pathways

Purpose

The purpose of this study was to investigate the changes in spherical equivalent (SE) and axial length (AL) and cumulative incidence of myopia and high myopia in Chinese 15-year-old adolescents entering a non-academic stream of senior high school education.

Methods

A total of 880 first-born twins with a baseline age range of 7 to 15 years were enrolled and followed annually until 18 years of age. Cycloplegic refractions and AL were examined. Educational exposure was divided into academic high school (AHS) and vocational high school (VHS) streams. A piecewise linear mixed-effects model was used to estimate the effect of education exposures on SE development, the slope before the age of 15 years (β2), and the slope change at the age of 15 years (β3) was compared between the 2 groups.

Results

The curves of refractive development in a myopic direction changed in parallel in the AHS and VHS group before 15 years. For nonmyopic children, β2 was -0.19 and -0.20 diopters (D)/year (P = 0.270), and β3 was 0.16 and 0.14 D/year (P = 0.270), in the AHS and VHS groups, respectively. Among patients with myopia, β2 was -0.52 and -0.54 D/year (P = 0.500), and β3 was 0.37 and 0.32 D/year (P = 0.004), in the AHS and VHS groups, respectively. The trends in AL were similar. The 3-year cumulative incidence of myopia was 35.3% (AHS) versus 14.7% (VHS; P < 0.001), and that of high myopia was 5.7% and 3.3% (P = 0.129).

Conclusions

Students undertaking a VHS rather than an AHS education have slower myopic shifts in refraction and less incident myopia after the age of 15 years.

L. S, Jeong J, Saw SM, Sevdalis N, Najjar RP. Light Therapy for Myopia Prevention and Control: A Systematic Review on Effectiveness, Safety, and Implementation

Purpose

This systematic review focuses on the effectiveness, safety, and implementation outcomes of light therapy as an intervention to prevent or control myopia in children.

Methods

A systematic literature search was performed in PubMed, EMBASE, CINAHL, SCOPUS, and Web of Science up to January 27, 2024. Effectiveness outcomes included myopia incidence, and changes in axial length (AL), spherical equivalent refraction (SER), and choroidal thickness (CT). Safety outcomes relating to retinal health or damage and implementation outcomes including compliance rates and loss to follow-up were extracted. ROBINS-I, ROB 2, and ROB-2 CRT were used to assess risk of bias.

Results

Nineteen interventional studies were included. Increased outdoor time (n = 3), red-light therapy (n = 13), and increased classroom lighting (n = 1) had a significant effect on myopia incidence, and changes in AL, SER, and CT. Violet-light therapy (n = 2) was only effective in children aged 8 to 10 years and children without eyeglasses with less than 180 minutes of near-work time daily. Two studies using red-light therapy reported adverse effects. For all studies, only compliance rates and loss to follow-up were reported on implementation effectiveness.

Conclusions

Evidence is compelling for the effectiveness of red-light therapy and outdoors time; more data are needed to confirm safety. Robust data are still needed to prove the effectiveness of violet-light and increased classroom lighting. Clearer implementation strategies are needed for all light therapies.

Translational Relevance

Light therapy has emerged as effective for myopia prevention and control. This systematic review summarizes the state of knowledge and highlights gaps in safety and implementation for these strategies.

Smartwatch Measures of Outdoor Exposure and Myopia in Children

Importance

Time spent outdoors has been proven effective in preventing myopia, but little is known about the association of outdoor exposure patterns with myopia.

Objective

To examine the association of outdoor exposure patterns with myopic shift in children.

Design, Setting, and Participants

This 1-year prospective cohort study from December 2017 to December 2018 was a secondary analysis of a cluster-randomized trial (Shanghai Time Outside to Reduce Myopia [STORM]). STORM was a school-based intervention study, recruiting 16 schools from 8 districts in Shanghai, from October 2016 to December 2018. Children without myopia at baseline who consistently wore a smartwatch for a minimum of 6 hours daily, sustained for at least 90 days, and who had complete information were included. Data analysis was performed from December 2017 to December 2018.

Exposures

The outdoor exposure pattern was defined as the episode of time outdoors and instant sunlight intensity over a continuous period.

Main Outcomes and Measures

Myopic shift was defined as the absolute change in refraction between the initial spherical equivalence and the follow-up spherical equivalence.

Results

This study included 2976 students (mean [SD] age, 7.2 [0.6] years; 1525 girls [51.2%]). The mean (SD) daily time outdoors was 90 (28) minutes, and the mean (SD) sunlight intensity was 2345 (486) lux. Of the 12 outdoor exposure patterns, the major outdoor exposure patterns were time outdoors with at least 15 minutes, accounting for 74.9% of minutes (33 677 584 of 45 016 800 minutes). Only patterns with at least 15 minutes accompanied with no less than 2000 lux were associated with less myopic shift in refraction (for ≥15 minutes and 2000 to 3999 lux, -0.007 diopter [D] [95% CI, -0.011 to -0.002 D]; for ≥15 minutes and ≥4000 lux, -0.006 D [95% CI, -0.010 to -0.002 D]). The isotemporal substitution of patterns with at least 15 minutes and 2000 lux for other outdoor exposure patterns was positively associated with less myopic shift.

Conclusions and Relevance

In this 1-year prospective cohort study of children with smartwatches, continuous outdoor exposure with at least 15 minutes accompanied with no less than 2000 lux sunlight intensity was associated with less myopic shift. These findings suggest that future outdoor interventions should focus not only on the overall time outdoors but also on the effective outdoor exposure patterns, as a means to effectively prevent myopia in children.

Prevalence of Myopia Among Schoolchildren and the Impact of Increased Screen Time: A Systematic Review

Myopia is the most frequent kind of refractive error and affects hundreds of millions of people. Growing evidence suggests that extended exposure to digital screens may exacerbate nearsightedness in children and young people. The purpose of this review is to compile data on the link between too much time in front of a screen and nearsightedness in young people so far. The principles of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guided the methods used and the format of the resulting report. Articles published between January 1, 2000, and June 30, 2023, were found by searching Medline, PubMed, ScienceDirect, Google Scholar, CINAHL, the Cochrane Library, and Scopus. Studies reporting an association between myopia and time spent in front of screens in children and young adults were considered eligible. The initial search yielded a total of 1,251 studies. After eliminating duplicates and reviewing the titles and abstracts, 64 full-text articles were evaluated for eligibility. Ultimately, 15 of these studies were included in the final analysis. The 15 studies involved a total of 59,775 participants and were conducted in various countries, including China, Singapore, and the United States. Overall, the evidence did not support a significant association between screen time and myopia in school children and young adults. There is conflicting evidence on the link between screen time and myopia in children and adolescents. More research is needed to determine whether or not digital screen use is a risk factor for myopia. The complex association between screen time and myopia is not fully understood at this time because of the variability of the included studies. These results have significant public health implications since they may be used to guide recommendations for screen time use in children and the young population.

Light exposure therapy for myopia control: a systematic review and Bayesian network meta-analysis

AIMS

To compare and rank the myopia control effects of different light wavelengths in children using a systematic review and Bayesian network meta-analysis (Bayesian NMA).

METHODS

The review protocol was registered with PROSPERO. We searched PubMed, EMBASE and MEDLINE for relevant clinical and animal studies published as of 2 February 2023. We included studies comparing red, violet or full-spectrum light with controls. Data extracted included descriptive statistics and study outcomes (axial length (AL) elongation and progression of spherical equivalent (SE) refraction). After quality assessment, estimates of treatment effect outcomes (mean differences (MDs) and 95% CIs) were first pooled for the animal and clinical studies in a traditional meta-analysis. To compare and rank the different light wavelengths, the Bayesian NMA was then conducted for all the included clinical studies (12 studies) and separately for only randomised controlled trials (8 studies). MDs, 95% credible intervals (CrIs) and ranks of the various light wavelengths were estimated in the Bayesian NMA.

RESULTS

When all clinical studies were included in the Bayesian NMA (12 studies), only red-light significantly slowed AL elongation, MD (95% CrI), -0.38 mm (-0.59 mm to -0.16 mm)/year and SE refraction progression, 0.72D (0.35D to 1.10D)/year compared with controls. It remained the only significant intervention when effect sizes from only RCTs (eight studies) were separately combined, (-0.28 mm (-0.40 mm to -0.15 mm)/year and 0.57D (0.22D to 0.92D)/year, for AL and SE refraction, respectively).

CONCLUSION

Myopia control efficacy varied among different wavelengths of light, with red light ranked as the most effective.

PROSPERO REGISTRATION NUMBER

Clinical studies: CRD42022368998; animal studies: CRD42022368671.

Temporal effects of an original myopia song on school children's myopia and awareness: a 3-year prospective study

CLINICAL RELEVANCE

Raising children's myopia prevention awareness and behaviour tends to exhibits a protective effect against myopia among schoolchildren.

BACKGROUND

To investigate the effect of an original myopia song in raising school children's awareness of healthier eye use behaviour and on myopia prevention.

METHODS

In this prospective randomised control study, two groups of students from one primary schools in Jiangxi, China, were enrolled and monitored from grade 3 to grade 6 (2016-2019). The primary outcome was the change in axial length (AL) after the intervention. Secondary outcomes included changes in spherical equivalent refraction (SER), near work and outdoor time, corrected near and distant visual acuity, visual discomfort score (VDS) and accommodative lag.

RESULTS

Four hundred students (193 females, 48.25%) aged 9.3 (range 8-10) years with emmetropia to moderate myopia were enrolled. Children in the myopia song group had a significantly shorter AL and less myopic refractive change than those in the control group (p = 0.04 and 0.02, respectively). Compared with the control group, children in the myopia song group spent less time on near work and more time outdoors (p = 0.04 and 0.04, respectively). At the final follow-up, the proportion of children with myopia was significantly lower in the myopia song group (30.5%) than in the control group (41%) (p = 0.03). No significant differences were found for the secondary outcomes, including corrected near and distant visual acuity, VDS and accommodative lag.

CONCLUSIONS

An original myopia song performed twice daily in primary schools appeared to have a modest effect on myopia control among school-aged children by changing their lifestyles in the long term.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Comparison of the long-term effects of atropine in combination with Orthokeratology and defocus incorporated multiple segment lenses for myopia control in Chinese children and adolescents

PURPOSE

The aim of this study was to evaluate the efficacy of Orthokeratology (Ortho-K), defocus incorporated multiple segment (DIMS) lens, combined Ortho-K/atropine, and combined DIMS/atropine for myopia control in children.

METHODS

A retrospective study included 167 myopic children aged 6-14 years with a spherical equivalent refraction (SER) of -0.75 to -4.00 diopter treated with Ortho-K (OK, n = 41), combined Ortho-K/atropine (OKA, n = 43), DIMS (n = 41), or combined DIMS/atropine (DIMSA, n = 42). Axial length (AL) was measured at baseline and at 3, 6, 9 and 12 months. Axial elongation over time and between groups were analysed.

RESULTS

After 12 months, the AL change was 0.20 ± 0.12 mm, 0.12 ± 0.14 mm, 0.22 ± 0.14 mm, and 0.15 ± 0.15 mm in the OK, OKA, DIMS, and DIMSA, respectively. There was no significant difference in AL change between OK and DIMS. OKA and DIMSA significantly slowed axial elongation compared to OK and DIMS monotherapy. After stratification by age, in the subgroup aged 6-10 years, there was significant difference in AL change between OKA and DIMS (p = 0.013), and no difference between other groups, while in the subgroup aged 10-14 years, the difference between OKA and DIMS became insignificant (p = 0.237), and the difference between OK and OKA, OK and DIMSA, DIMS and DIMSA became significant.

CONCLUSIONS

Ortho-K and DIMS lenses show similar reductions in myopia progression among children with low initial myopia. Atropine can significantly improve the efficacy of myopia control of both Ortho-K and DIMS lenses, and this add-on effect is better in older children.

Myopia Control: Are We Ready for an Evidence Based Approach?

INTRODUCTION

Myopia and its vision-threatening complications present a significant public health problem. This review aims to provide an updated overview of the multitude of known and emerging interventions to control myopia, including their potential effect, safety, and costs.

METHODS

A systematic literature search of three databases was conducted. Interventions were grouped into four categories: environmental/behavioral (outdoor time, near work), pharmacological (e.g., atropine), optical interventions (spectacles and contact lenses), and novel approaches such as red-light (RLRL) therapies. Review articles and original articles on randomized controlled trials (RCT) were selected.

RESULTS

From the initial 3224 retrieved records, 18 reviews and 41 original articles reporting results from RCTs were included. While there is more evidence supporting the efficacy of low-dose atropine and certain myopia-controlling contact lenses in slowing myopia progression, the evidence about the efficacy of the newer interventions, such as spectacle lenses (e.g., defocus incorporated multiple segments and highly aspheric lenslets) is more limited. Behavioral interventions, i.e., increased outdoor time, seem effective for preventing the onset of myopia if implemented successfully in schools and homes. While environmental interventions and spectacles are regarded as generally safe, pharmacological interventions, contact lenses, and RLRL may be associated with adverse effects. All interventions, except for behavioral change, are tied to moderate to high expenditures.

CONCLUSION

Our review suggests that myopia control interventions are recommended and prescribed on the basis of accessibility and clinical practice patterns, which vary widely around the world. Clinical trials indicate short- to medium-term efficacy in reducing myopia progression for various interventions, but none have demonstrated long-term effectiveness in preventing high myopia and potential complications in adulthood. There is an unmet need for a unified consensus for strategies that balance risk and effectiveness for these methods for personalized myopia management.

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

PURPOSE

Considering the putative role of light in myopia, and variations in socioeconomic, lifestyle, educational and environmental factors across ethnicities, we objectively investigated light exposure patterns in Indian school children.

METHODS

The light exposure profile of 143 school children (9-15 years, 50 myopes) recorded using a validated wearable light tracker for six continuous days was analysed. Additional data for non-school days were available for 87 children (26 myopes). The illuminance exposure levels, time spent outdoors and epoch (number of times participant is exposed to a predefined range of lux level per day) were compared between myopes and non-myopes across different light conditions: ≥1000, ≥3000, ≥5000 and ≥10 000 lux. For school days, light exposure profiles during (1) before school, school and after school hours; and (2) class, break and transition (when a student travels to and from school) time were analysed.

RESULTS

The overall median (IQR) daily illuminance exposure level, time spent outdoors and epochs at outdoors (≥1000 lux) were 807 (507-1079) lux/day, 46 (30-64) min/day and 9 (6-12) times/day, respectively. The daily illuminance exposure on non-school days was significantly higher in non-myopes than myopes (6369 (4508-9112) vs 5623 (2616-6929) lux/day, p=0.04). During transition time (school days), non-myopes had significantly higher illuminance exposure (910 (388-1479) vs 550 (263-1098) lux/day, p=0.04), spent more time outdoors (25 (10-43) vs 14 (4-29) min/day, p=0.01) and had higher outdoor epochs (6 (4-11) vs 5 (2-8) times/day, p=0.01) than myopes.

CONCLUSIONS

A small but significant difference in illuminance exposure, time spent outdoors and epoch was noted between myopes and non-myopes during transition time, which may have implications in myopia control.

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

BACKGROUND

Although school screenings identify children with vision problems and issue referrals for medical treatment at an ophthalmic hospital, the effectiveness of this approach remains unverified.

OBJECTIVE

To investigate the impact of ophthalmic clinical services on the onset and progression of myopia in preschool children identified with vision impairment.

METHODS

Using data from the Shanghai Child and Adolescent Large-scale Eye Study (SCALE), this retrospective cohort study evaluated the visual development of children from three districts-Jing'an, Minhang, and Pudong-which are representative of geographic diversity and economic disparity in Shanghai's 17 districts. Initially, in 2015, the study encompassed 14,572 children aged 4-6 years, of whom 5,917 needed a referral. Our cohort consisted of 5,511 children who had two or more vision screenings and complete personal information over the follow-up period from January 2015 to December 2020. We divided these children into two groups based on their initial spherical equivalent (SE): a High-risk group (SE > -0.5 D) and a Myopia group (SE ≤ -0.5 D). Within each of these groups, we further categorized children into Never, Tardily, and Timely groups based on their referral compliance to compare the differences in the occurrence and progression of myopia. Cox proportional models were applied to estimate hazard ratios (HRs) for myopia incidence per person-years of follow-up in High-risk group. Generalized additive models(GAM) was used to calculating the progression for annual spherical equivalent changes in all children.

RESULTS

Of the 5,511 preschool children (mean age, 5.25 years; 52.24% male) who received a referral recommendation, 1,327 (24.08%) sought clinical services at an ophthalmic hospital. After six years of follow-up, 65.53% of children developed myopia. The six-year cumulative incidence of myopia in the Never, Tardily, and Timely groups was 64.76%, 69.31%, and 57.14%, respectively. These percentages corresponded to hazard ratios (HRs) of 1.31 (95% CI, 1.10-1.55) for the Tardily group and 0.55 (95% CI, 0.33-0.93) for the Timely group, compared with the Never group. The HRs were adjusted for age, sex, and SE at study entry. Interestingly, the Timely group showed significantly less SE progression than the other groups (P < 0.001), and SE progression was higher in the High-risk group (-0.33 ± 0.37D/year) than in children with myopia (-0.08 ± 0.55D/year).

CONCLUSION

Timely utilization of ophthalmic clinical services among children aged 4 to 6 years who fail school vision screenings can significantly reduce the incidence of myopia and slow SE progression.

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

BACKGROUND

This bibliometric analysis explored the knowledge structure of and research trends in the relationship between light and myopia.

METHODS

Relevant literature published from 1981 to 2024 was collected from the Web of Science Core Collection database. Visual maps were generated using CiteSpace and VOSviewer. We analyzed the included studies in terms of the annual publication count, countries, institutional affiliations, prolific authors, source journals, top 10 most cited articles, keyword co-occurrence, and cocitations.

RESULTS

A total of 525 papers examining the relationship between light and myopia published between 1981 and 2024 were collected. The United States ranked first in terms of the number of publications and actively engaged in international cooperation with other countries. The New England College of Optometry, which is located in the United States, was the most active institution and ranked first in terms of the number of publications. Schaeffel Frank was the most prolific author. The most active journal in the field was Investigative Ophthalmology & Visual Science. The most frequently cited paper in the included studies was written by Saw, SM and was published in 2002. The most common keywords in basic research included "refractive error," "longitudinal chromatic aberration," and "compensation." The most common keywords in clinical research mainly included "light exposure," "school," and "outdoor activity." The current research hotspots in this field are "progression," "refractive development," and "light exposure." The cocitation analysis generated 17 clusters.

CONCLUSION

This study is the first to use bibliometric methods to analyze existing research on the relationship between light and myopia. In recent years, the intensity and wavelength of light have become research hotspots in the field. Further research on light of different intensities and wavelengths may provide new perspectives in the future for designing more effective treatments and interventions to reduce the incidence of myopia.

The Impact of Sunshine Duration on Myopia in Central China: Insights from Populational and Spatial Analysis in Hubei

Purpose

This study aimed to analyze myopia distribution in Hubei and the impact of regional Sunshine Duration on myopia in children and adolescents.

Patients and Methods

The Cross-sectional study included students (kindergarten to grade 12) through multistage cluster stratified sampling in 17 cities (103 areas) of Hubei, China, who underwent ophthalmic examinations from September 2021 to November 2021. The association of sunshine duration with the prevalence and distribution of myopia was analyzed. Using Moran's index to quantify the distribution relationship, a spatial analysis was constructed.

Results

A total of 435,996 students (53.33% male; mean age, 12.16±3.74 years) were included in the study. A negative association was identified between myopia prevalence and sunshine duration in the region, especially in population of primary students (r=-0.316, p<0.001). Each 1-unit increment in the sunshine duration was associated with a decreased risk of myopia prevalence (OR=0.996; 95% CI, 0.995-0.998; P <0.001). Regression showed a linear relationship between sunshine duration and myopia rates of primary school students [Prevalence%= (-0.1331*sunshine duration+47.73)%, p = 0.02]. Sunshine duration influenced the distribution of myopia rates among primary (Moran's I=-0.206, p<0.001) and junior high school (Moran's I=-0.183, p=0.002). Local spatial analysis showed that areas with low sunshine duration had high myopia prevalence concentration.

Conclusion

This study revealed sunshine duration associations with myopia prevalence at the regional and population levels. The results may emphasize the significance of promptly implementing myopia control in regions with poor sunshine. The effect of sunshine on myopia is pronounced in the early years of education, especially in primary students.

Myopia Is an Ischemic Eye Condition: A Review from the Perspective of Choroidal Blood Flow

Myopia is a common refractive error that affects a large proportion of the population. Recent studies have revealed that alterations in choroidal thickness (ChT) and choroidal blood flow (ChBF) play important roles in the progression of myopia. Reduced ChBF could affect scleral cellular matrix remodeling, which leads to axial elongation and further myopia progression. As ChT and ChBF could be used as potential biomarkers for the progression of myopia, several recent myopia treatments have targeted alterations in ChT and ChBF. Our review provides a comprehensive overview of the recent literature review on the relationship between ChBF and myopia. We also highlight the importance of ChT and ChBF in the progression of myopia and the potential of ChT as an important biomarker for myopia progression. This summary has significant implications for the development of novel strategies for preventing and treating myopia.

Is Spending More Time Outdoors Able to Prevent and Control Myopia in Children and Adolescents? A Meta-Analysis

INTRODUCTION

Spending more time outdoors was treated as a safe and cost-effective method to prevent and control myopia. While prior research has established an inverse association between outdoor time and the risk of myopia onset, the effect of increasing outdoor time in delaying the progression of myopia remains a subject of debate. The present meta-analysis aimed to assess the relationship between outdoor time and the myopia onset, and further examine whether there is a dose-response relationship between outdoor time and the risk of myopia onset. Meanwhile, perform whether the outdoor time is related to delaying the progression of myopia.

METHODS

Studies were retrieved from PubMed, Web of Science, Embase, Medline, and the Cochrane Database, spanning from their inception to February 2023. Three cohort studies and 5 prospective intervention studies were included, with a total of 12,922 participants aged 6-16 years.

RESULTS

Comparing the highest with the lowest exposure levels of time spent outdoors, the highest outdoor time was strongly associated with a reduced risk of myopia onset (odds ratio [OR]: 0.53; 95% confidence interval [CI]: 0.34, 0.82). A nonlinear dose-response relationship was found between outdoor time and myopia onset risk. Compared to 3.5 h of outdoor time per week, an increase to 7, 16.3, and 27 h per week corresponded with a respective reduction in the risk of myopia onset by 20%, 53%, and 69%. Among children and adolescents who were not myopic, spending more time outdoors significantly slowed down the speed of change in spherical equivalent refractive (weighted mean difference [WMD] = 0.10D, 95% CI: 0.07, 0.14) and axial length (WMD = -0.05 mm, 95% CI: -0.06, -0.03). Among children and adolescents who were already myopic, spending more time outdoors did not slow myopia progression.

CONCLUSIONS

Overall, spending more time outdoors can prevent the onset of myopia, but it does not seem to slow its progression. Further studies are needed to better understand these trends.

How can we better evaluate paediatric progression of myopia and associated risk factors? Lessons from the COVID-19 pandemic: A systematic review

PURPOSE

During the COVID-19 pandemic, home-based and remote learning-particularly using electronic devices-was rapidly pushed out. Increased near-work, screen time exposure and lack of outdoor time are risk factors that contribute to childhood myopia, but it is difficult to adopt recommendations from prior publications as a consistent limitation in the literature is the heterogeneity of research methodology. This review seeks to systematically evaluate how observational studies published during the pandemic have quantified and measured risk factors and myopia in school-going children and adolescents.

METHODS

Three scientific databases (PubMed, CINAHL, Scopus) were systematically searched from March 2020 to April 2022. Findings from relevant studies were descriptively summarised in relation to the PICOS-based objective of the review.

RESULTS

The final sample of 13 studies included research from six countries and comprised 1 411 908 children and adolescents. The majority of studies (N = 10; 76.9%) used spherical equivalent refraction (SER) of -0.5 dioptres or lower as a common definition of myopia. Most studies (77.8%) measuring screen time exposure found it higher during COVID-19 compared to pre-COVID, but only one study used objective measurement of screen time. The average critical appraisal score of the sample was only 66.1%, with a considerable number of studies failing to identify and adjust for potential confounders.

CONCLUSION

Future studies should consider emergent objective and validated measures of risk factors, account for potential a priori confounders and covariates and ensure more representativeness in the sociodemographic makeup of their samples.

Inverse L-Shaped Association Between Body Mass Index and Myopia in Chinese Schoolchildren: A Pilot Study

Purpose

The prevalence of obesity and myopia in young people is increasing worldwide; however, the association between body mass index (BMI) and myopia remains controversial. This study aimed to assess the association between BMI and myopia in Chinese schoolchildren.

Patients and Methods

In this study, the open data for analysis were obtained from DATADRYAD website (www.datadryad.org). A total of 3658 children were enrolled in this study. Logistic regression model was used to analyze the relationship between BMI and myopia.

Results

Compared with individuals with lower BMI Q1 (less than 25 kg/m2), the adjusted odds ratios (ORs) for BMI and myopia were 2.15 (95% confidence interval [CI]: 1.62-2.86) in Q2 (25.0-29.9 kg/m2) and 2.39 (95% CI: 1.37-4.18) in Q3 (30.0 kg/m2 or more). Moreover, the association between BMI and myopia exhibited an inverted L-shaped curve (nonlinear; p < 0.001). When the BMI was <25 kg/m2, an increased BMI was significantly associated with a higher risk of myopia (OR = 1.244 [95% CI: 1.211-1.277], p < 0.001). However, when the BMI was ≥25 kg/m2, the association lost its significance (OR = 1.063 [95% Cl: 0.964-1.171], p = 0.219).

Conclusion

This study found an inverted L-shaped association between BMI and myopia in Chinese schoolchildren. A higher BMI was associated with a higher risk of myopia reaching 25 kg/m2, after which an increase in BMI was no longer associated with an increased risk of myopia.

Toward early intervention based on age-specific vision checkups: A vision impairment survey in Yantai, China

The prevalence of myopia among children and adolescents is currently rising to alarming levels (>80%) in China. This study used several routinely collected demographic factors to quantify myopia and glass-wearing rates for primary and secondary school students. We identified myopia risk factors and proposed new aspects for early intervention. This study was a cross-sectional survey of myopia and glass-wearing rates for students (6-18 years old) in Yantai, China. We collected both vision (vision acuity [VA] and spherical equivalence [SE]) and glass-wearing information to establish respective logistic models for quantifying myopia and glass-wearing rate. We further propose a joint decision region (VA, SE, age) to guide early intervention. Among 10,276 children, 63% had myopia (65% wore glasses). The prevalence of myopia increases with age and levels off during adulthood. Females had a higher overall prevalence rate than males (P < .001). The rural age mode (≈15.5) is about 2 years larger than the urban age (≈13.5) for myopia students. For the myopia rate, in the age ≤14.5, the linear age effect was significant (odds ratio [OR] = 1.73, P < .0001), males had a significant negative baseline effect at the start of schooling (vs. females) (OR = 0.68, P < .0001), and the urban group had a significant positive baseline effect (vs. rural) (OR = 1.39, P < .0001). The correlation between VA and SE increases with age and has a directional shift (from negative to positive) at ages 8 to 9. For the glass-wearing rate, age had a significant positive effect (OR = 1.25, P < .0001), VA had a significant negative effect (OR = 0.002, P < .0001), and body mass index had a slightly significant positive effect (OR = 1.02, P = .03). Urban female have a higher myopia rate than rural male at the start of schooling, and vocational high school has improved vision upon high school. Body mass index was not a significant factor for myopia. The myopia rate model is specific to age range (separated at 14.5 years old). Students of lower ages are less likely to wear glasses for correction, and this may require intervention. The temporal age-specific (VA, SE) correlations and joint distributions strengthen the speculation in the literature that age 8 to 9 is a critical intervention period and motivates us to propose a rigorous intervention decision region for (age, VA, and SE) which mainly applies for this tight age period.

The Relationship between Myopia and Obesity in Adults

PURPOSE

To investigate the relationship between myopia and obesity through direct measurements of fat content.

METHODS

A cross-sectional study used a stratified, multistage survey, the Korea National Health and Nutrition Examination Survey (2008-2010). Subjects 19 years or older (n = 10,305) were included. Participants were divided into three groups according to refractive status: myopia (spherical equivalent [SE] ≤ -1.0 diopter [D]), emmetropia (-1.0 D < SE ≤ 1.0 D), and hyperopia (SE > 1.0 D). Obesity was investigated with assessment of fat mass and body mass index or waist circumference. Fat mass was measured with whole-body dual energy x-ray absorptiometry. Body fat percentage was calculated as (total fat mass / body weight × 100).

RESULTS

Higher obesity index was found in individuals with myopic eyes after adjustment for age, sex, education level, income status, physical activity, residence, and serum vitamin D level. The significant difference in total body fat percentages among myopia, emmetropia, and hyperopia was significant in the young age group (19-39 years, p < 0.05) but not in the middle age group (40-64 years) and the old age group (≥65 years). Individuals with a higher percentage of total body fat had greater odds ratios for myopia (fourth quartile of body fat; odds ratio, 1.352; 95% confidence interval, 1.178-1.551).

CONCLUSIONS

An association was found between adiposity and myopia in relatively young adults using direct measurements of fat mass.