Genetic and environmental effects on myopia development and progression

Combination Therapy with Atropine 0.05% and Myopi-X® Glasses: Is it Effective in Myopia Control?

Objectives

To investigate whether the combination therapy of Myopi-X® peripheral progressive addition lenses (PAL; Novax®) and atropine 0.05% provides an additive effect compared to monotherapies with either Myopi-X® PAL or atropine 0.05%.

Materials and Methods

This retrospective cross-sectional study reviewed the clinical records of 51 patients, categorized into three groups: 27 in the Myopi-X group, 13 in the atropine 0.05% group, and 11 in the combination therapy group using Myopi-X peripheral PAL with atropine 0.05%. Baseline characteristics, including age, cycloplegic spherical equivalent (SE), and axial length (AL), were compared between the groups. Twelve months after treatment initiation, changes in SE and AL were assessed and compared between the groups.

Results

Among the 51 patients analyzed, the baseline characteristics differed significantly between the groups, with the atropine 0.05% group showing a higher average age, longer AL, and lower SE compared to the other groups. After 12 months, no significant differences were found in SE changes between the treatment groups (p=0.35). Similarly, changes in AL did not significantly differ between the groups (p=0.10), although age had a significant impact on AL change (p=0.01). No significant differences were observed in pairwise comparisons of SE or AL changes between the groups.

Conclusion

In this study, combining atropine 0.05% with Myopi-X PALs did not provide an additive benefit. The literature suggests that both treatments are effective in slowing myopia progression individually; however, in our study, their combination did not significantly improve SE progression or axial elongation compared to monotherapies. Further randomized studies with larger patient groups are needed to confirm these findings and assess long-term effects.

Deep anterior chamber depth may be a risk factor for axial length growth in children

Objective

To investigate and evaluate the progression of myopia and associated factors of axial length (AL) growth among children in Chongqing.

Methods

This six-month prospective study was conducted on students in grades 1 to 8 at a school in Chongqing, China. All participants underwent a standard ophthalmologic examination including uncorrected visual acuity (UCVA), noncycloplegic refraction, AL, and corneal topography in March 2023. Six months later, the above examinations were repeated to obtain follow-up data. Visual habits questionnaire was gained to analyze the correlation between the AL growth and vision-related behavior.

Results

A total of 417 students from Chongqing were enrolled in this study. The myopia prevalence was higher in follow-up (38.6%) than in baseline (33.3%) and the AL was longer in follow-up than in baseline (23.69 ± 1.03 mm vs. 23.57 ± 1.03 mm, p < 0.001). The anterior chamber depth (ACD) in students with AL growth greater than or equal to 0.2 mm (3.16 ± 0.23 mm) was deeper than that in students with AL growth less than or equal to 0.05 mm (3.02 ± 0.28 mm, p = 0.001), lens thickness (LT) was thinner (3.29 ± 0.10 mm vs. 3.33 ± 0.10 mm, p = 0.004). Furthermore, ACD was positively correlated with AL growth. (r = 0.181, p < 0.001).

Conclusion

Compared to SE, AL serves as a more sensitive indicator for monitoring myopia progression. ACD was positively correlated with AL growth, and deeper ACD may be contributed to longer AL growth.

The association between sleep duration and myopia among Chinese school-age students: mediation effect of physical activity

Background

This study aimed to investigate the relationship between sleep duration and myopia in school-age students, as well as to observe the role of physical activity as a mediating variable in sleep duration and myopia.

Methods

Using multistage stratified sampling, 26,020 school-age students in Jiangsu Province, ages 7-18, were selected for this cross-sectional survey. Each participant completed a standardized interview in which their were asked about their vision, level of physical activity and average hours of sleep per day over the past month. Visual acuity examinations were conducted by the testing team's ophthalmology professionals and they were categorized into two groups based on pre-set criteria: myopic and non-myopic. Sleep duration was classified into 3 categories: <8 h/d, 8-10 h/d, >10 h/d. The Pearson's chi-square tests were used to examine differences in the incidence of myopia among participants. Binary multifactorial logistic regression adjusted for potential confounding variables was used to examine the relationship between myopia and a variety of factors. The mediating effects of physical activity on sleep duration and myopia were analyzed using the AMOS model.

Results

In this study, the incidence of myopia was higher in females than in males, it also increased with age. Those who slept for <8 h/d had the greatest myopia rate (85.69%) compared with those who slept for≥8 h/d (p < 0.001). Sleep duration was found to be adversely correlated with myopia (sleep duration = 8-10 h/d: OR = 0.68, p < 0.01; sleep duration > 10 h/d: OR = 0.48, p < 0.01) after controlling for potential confounders like gender, age, and BMI-z score (Body Mass Index Score). Physical activity at a high intensity not moderate intensity was found to be protective factor against myopia. High-intensity physical activity also acted as a mediator in the negative association between sleep duration and myopia (a, b, c' all p < 0.05).

Conclusion

There is a negative correlation between sleep duration and myopia in school-age students, and that high-intensity physical activity mediates the relationship between sleep duration and myopia.

Ocular biometric parameters in Chinese preschool children and physiological axial length growth prediction using machine learning algorithms: a retrospective cross-sectional study

OBJECTIVES

To examine the ocular biometric parameters and predict the annual growth rate of the physiological axial length (AL) in Chinese preschool children aged 4-6 years old.

METHODS

This retrospective cross-sectional study included 1090 kindergarten students (1090 right eyes) between the ages of 4 and 6 years from Pinggu and Chaoyang District, Beijing. Dioptre values were ascertained following cycloplegic autorefraction. Predicted AL was obtained through the application of the Gaussian process regression model as an optimisation technique. Subsequently, the annual growth rate of physiological AL for non-myopic preschool children (n=1061) was computed via the backward difference method.

RESULTS

In total, 85.4% of preschool children (931 individuals) had hyperopic refractive status in the 4-6 years age group, while only 2.7% (29 individuals) showed myopia. Boys had longer AL, larger AL-to-corneal radius ratio, deeper anterior chamber depth and lower lens power. The average physiological axial growth for boys and girls ranged from 0.050 mm/year to 0.165 mm/year and 0.063 mm/year to 0.168 mm/year, respectively. As age increased, the physiological AL growth in non-myopic cases decreased. Additionally, as hyperopic spherical equivalent refraction error lessened, the physiological AL growth component slowed down.

CONCLUSIONS

In preschool children, refractive development predominantly exhibits mild hyperopia. The concept of physiological AL provides valuable insights into the complexities of ocular development.

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.

Assessing Educational Impact of Worldwide Webinar on Management of Myopia Progression in Children

OBJECTIVE

To assess the educational impact of a worldwide webinar approach to myopia progression management in children <8 years and 8-12 years old.

DESIGN

Cross-sectional study.

METHODS

A self-administered survey was conducted for attendees of a 3 h worldwide webinar held in two parts on consecutive days on the management of myopia progression in children. The survey was administered before, immediately after completion of the webinar, and 8 weeks later; responses were recorded on a Likert scale. Questions were posed to assess (a) the confidence of attendees in managing myopia in children <12 years old, (b) attendees' understanding of latest treatment options, (c) any improvement in attendees' knowledge after the webinar, and (d) any changes made to practice 8 weeks after the webinar. Pre- and post-responses were analyzed using an unpaired two-tailed t-test.

RESULTS

The webinar had 701 and 606 global attendees on the first and second days, respectively. Based on a comparison of contact information, 372 attendees participated on days 1 and 2, meaning 288 and 233 participants attended only day 1 and day 2, respectively. There was a significant increase in the percentage of attendees who were "very confident" in managing myopia after the webinar (p < 0.05). Ninety-nine attendees completed the survey at 8 weeks. Of these, 76% believed that the webinar had "very significantly" or "significantly" improved their ability to manage pediatric myopia and 91% had implemented or intended to implement a change in their practice. The respondents who did not implement a change identified cost and patient compliance as the common barriers.

CONCLUSION

There is a tsunami of research and management options in the field of myopia management at present. We demonstrate that an effective way of disseminating information and education about myopia management is a pre-designed comprehensive webinar held over two consecutive days. There is evidence that such a webinar may also influence a change in clinical practice.

Dynamics of Myopia Progression in Ghana-Evidence From Clinical Practice: A Retrospective Cohort Study

Background and Aim

To investigate the pattern of progression of myopia among a Ghanaian clinical cohort.

Methods

A retrospective cohort analysis of a clinical data set of all healthy myopic participants attending a tertiary eye care center was performed. Participants' biennial refraction examinations were tracked for refractive changes 4 years after the date of the first visit. This covered the period from January 2015 to December 2019. Myopia progression was defined as a difference in spherical equivalent between consecutive biennial visits equal to, or greater than -0.50 D of myopia.

Results

The medical records of 169 myopic participants were reviewed, with the majority (53.8%) being female. Most of the participants (51.4%) were younger than 36 years, and at the end of the study period, 96 participants (56.8%), who made up the majority, showed progression of myopia Univariate regression revealed that the 36-59-year-old age range is associated with a 60% [cOR = 0.40, 95% CI: -0.17, 0.97; p = 0.04] reduced likelihood compared to those belonging to the 0-17-year-old age group, and the Mole-Dagbon ethnicity is associated with an almost fourfold [cOR = 3.80; 95% CI: -1.40, 10.316; p = 0.01] increased likelihood of experiencing myopia progression compared to those of Ga-Adangbe ethnicity. Multivariate regression revealed that the Mole-Dagbon ethnicity is associated with an increased likelihood of experiencing myopia progression 4 years after their initial visit [aOR = 3.49; 95% CI: -1.27, 9.63; p = 0.02] compared to those of Ga-Adangbe ethnicity.

Conclusion

Our study provides important insights into myopia progression in Ghana, with findings that are consistent with global trends. The association of myopia progression with age, place of residence, degree of myopia, and ethnicity highlights the need for tailored interventions to manage this growing public health concern in African populations.

Myopia in Children: Epidemiology, Genetics, and Emerging Therapies for Treatment and Prevention

Refractive errors, particularly myopia, are among the most prevalent visual impairments globally, with rising incidence in children and adolescents. This review explores the epidemiology and risk factors associated with the development of refractive errors, focusing on the environmental and lifestyle factors contributing to the current surge in myopia. We provide an overview of key genetic factors and molecular pathways driving the pathogenesis of myopia and other refractive errors, emphasizing the complex interplay between genetic predisposition and environmental triggers. Understanding the underlying mechanisms is crucial for identifying new strategies for intervention. We discuss current approaches to slow myopia progression in pediatric populations, including pharmacological treatment regimens (low-dose atropine), optical interventions, and lifestyle modifications. In addition to established therapies, we highlight emerging innovations, including new pharmacological agents and advanced optical devices, and insights into potential future treatments. Cutting-edge research into gene therapy, molecular inhibitors, and neuroprotective strategies may yield novel therapeutic targets that address the root causes of refractive errors. This comprehensive review underscores the importance of early intervention and highlights promising avenues for future research, aiming to provide pediatricians with guidance to ultimately improve clinical outcomes in managing and preventing myopia progression in children and young adults.

Impact of physical indicators on ocular development in preschool children

Objective

Understanding the impact of early childhood physical growth on visual development is crucial, as this period marks a critical phase for foundational physical and ocular maturation. The aim of the current study was to investigate the associations between the anthropometric indicators of height, weight, and body mass index (BMI), as well as visual acuity, refraction, and ocular biometrics, in Chinese preschool children.

Methods

This cross-sectional study consisted of 1,477 Chinese 3- to 6-year-old preschool children from nine kindergartens in Tongzhou District, Beijing. Demographic data, height and weight were measured according to a standard protocol, and BMI was calculated. Refractive error was measured via autorefraction in eyes under cycloplegia. Axial length (AL), anterior chamber depth (ACD), lens thickness, and corneal curvature were measured via an IOL Master. The axial length-corneal radius (AL-CR ratio) was defined as the AL divided by the mean corneal radius of curvature. Multivariate linear regression models were used to explore the cross-sectional associations between physical indicators (height, weight and BMI) and visual acuity and ocular developmental parameters in boys and girls.

Results

Compared with the children in the fourth quartile for height for a given age and sex, the visual acuity in the fourth quartile was 0.08 less, the refraction was 0.11 D more negative (1.22 D versus 1.33 D), the axial length was 0.62 mm longer, the anterior chamber depth was 0.18 mm deeper, the lens thickness was 0.13 mm thinner, the corneal radius of curvature was 0.1 mm less, and the AL-CR ratio was higher after adjustments were made for age and weight. The association between BMI and visual acuity was statistically significant in girls but not in boys. Older and more obese children had better visual acuity (p < 0.001) after adjustments were made for age.

Conclusion

Height and higher BMI remained independently related to VA condition, AL and ACD elongation, and corneal flattening in preschool children after controlling for various covariates. These results provide critical insights into pediatric ocular health and emphasize the importance of early detection and intervention in both physical and ocular health in early childhood development.

DNA methylation biomarkers and myopia: a multi-omics study integrating GWAS, mQTL and eQTL data

BACKGROUND

This study aimed to identify DNA methylation biomarkers associated with myopia using summary-data-based Mendelian randomization (SMR).

METHODS

A systematic search of the PubMed, Web of Science, Cochrane Library, and Embase databases was conducted up to March 27, 2024. SMR analyses were performed to integrate genome-wide association study (GWAS) with methylation quantitative trait loci (mQTL) and expression quantitative trait loci (eQTL) studies. The heterogeneity in the dependent instrument (HEIDI) test was utilized to distinguish pleiotropic associations from linkage disequilibrium.

RESULTS

The systematic review identified 26 DNA methylation biomarkers in five studies, with no overlap observed among those identified by different studies. After integrating GWAS with multi-omics data of mQTL and eQTL, six genes were significantly associated with myopia: PRMT6 (cg00944433 and cg15468180), SH3YL1 (cg03299269, cg11361895, and cg13354988), ZKSCAN4 (cg01192291), GATS (cg17830204), NPAT (cg04826772), and UBE2I (cg03545757 and cg08025960).

CONCLUSIONS

We identified six methylation biomarkers associated with the risk of myopia that may be helpful to elucidate the etiology mechanisms of myopia. Further experimental validation studies are required to corroborate these findings.

The concept of cone opponency may extend beyond accommodation, to myopiagenesis and emmetropization, for a better peripheral defocus lens

Myopia has ever-rising prevalence in the past few decades globally. Its pathogenesis is still not adequately elucidated especially at the signal transduction level. For the environmental risk factors, there is a large body of fragmented knowledge about the visual inputs for accommodation, myopiagenesis and emmetropization, with the latter two being essentially local processes. The red-green and yellow-blue chromatic pathways, together with the underlying L-M and S-(L+M) cone opponency, seem to be the common denominator amongst them. In this review, experimental and observational evidence are summarized to delineate the interplay of them. This review may establish the pivotal role of longitudinal chromatic aberration (LCA) for a mechanistic approach to future research in myopia control. This review looks into the mechanistic processes underlying myopiagenesis and emmetropization, specifically focusing on chromatic aberration and cone opponency in vision as pivotal components. The roles of longitudinal chromatic aberration (LCA) and cone contrast in myopia onset and development are intriguing. How visual input and chromatic pathways (specifically, red-green and blue-yellow cone opponency) contribute to accommodation that may trigger emmetropization mechanisms, thereby influencing eye growth patterns are explored and discussed. In brief, this manuscript delves into the physiology of visual processing and highlights a foundational aspect of visual science that may account for a "Go" or "Stop" signaling in axial eye growth. It further proposes a metric to gauge myopia-inhibiting optical devices such as the peripheral defocus lenses, for its best iteration. Future research in the above-mentioned areas is warranted.

Peripheral Contrast Reduction Optically Induced by Scattering Lenses Thickens Peripheral Choroid

Purpose

The mechanisms underlying a myopia control strategy using scattering lenses are unclear. Therefore, this study investigates the short-term effects of scatter lenses on central and peripheral choroidal thickness and axial length, which serve as a biomarker in myopia progression research.

Methods

In total, 23 participants underwent a 60-minute lens wear phase each to five lens conditions: medium peripheral scattering, high peripheral scattering, medium full-field scattering, high full-field scattering and control (clear lens). Central and peripheral choroidal thickness, foveal axial length, and central visual acuity were measured before and after each lens wear condition.

Results

Peripheral choroidal thickening was found after the lens wear phase of the medium peripheral scattering condition (+3.91 ± 5.37 µm, P = 0.04), revealing a significant difference to the control lens condition (P = 0.004), most pronounced in the superior peripheral retina (+1.95 ± 10.74 µm, P = 0.02). In the central retina, significant choroidal thickening was only found in the nasal part after exposure to medium full-field scattering (+3.91 ± 11.72 µm) compared to the control condition (P = 0.001). High peripheral and full-field scattering conditions did not significantly affect central or peripheral choroidal thickness. Visual acuity was significantly reduced in the full-field scattering conditions compared to control and peripheral scattering lenses, with no improvement after 60-minute lens wear. Axial length did not differ significantly after 60-minute exposure to any scattering lens condition or when compared to the control lens.

Conclusions

The results indicate a local retinal contrast detection mechanism signals the choroid to thicken peripherally after adaptation to medium peripheral scattering but not high peripheral scattering or full-field scattering at all, while central thickening was only significant nasally after exposure to medium full-field scattering. This emphasizes the importance of the peripheral retina and the level of contrast reduction in the context of myopia research.

Translational Relevance

This finding gives insight into the mechanism behind the myopia control strategy inducing peripheral scattering.

Spatial epidemiological characteristics and driving factors of myopia among school-age children based on geographical detector: a national study

The present study aimed to examine the spatial characteristics of myopia and identify the socioeconomic and environmental factors influencing its prevalence. Myopia prevalence among children of school age of Han ethnicity in China was 56.6% in 2019, with the highest and lowest prevalence's in Shandong (66.8%) and Guizhou (47.3%), respectively. There was a spatial aggregation of myopia prevalence in China. Environmental factors (atmospheric PM2.5 concentration and forest coverage) and socioeconomic factors (gross domestic product per capita, per capita disposable income, hospital beds per thousand people, and Engel coefficient) have significant influences on myopia prevalence. The interaction of each factor on myopia showed nonlinear enhancement. Myopia prevalence among children of school age was spatially clustered, and environmental and socioeconomic conditions are associated with myopia prevalence. Our findings provide novel perspectives for the comprehensive prevention and control of myopia.

Knowledge, attitude, and practice of non-ophthalmic medical staff toward myopia-related fundus lesions

This study assessed the knowledge, attitude, and practice (KAP) of non-ophthalmic medical staff towards myopia-related fundus lesions. This multicenter, cross-sectional study enrolled non-ophthalmic medical staff of Suining City between January and May 2023 using a self-designed questionnaire. A total of 505 (93.19%) valid questionnaires were included. Their mean KAP scores were 8.10 ± 2.32 (range: 0-12), 20.27 ± 2.68 (range: 0-24), and 17.77 ± 5.04 (range: 0-28), respectively. Structural equation modeling indicated that knowledge has a positive effect on attitude (β = 0.307, P < 0.001), and attitude has a positive effect on practice (β = 0.604, P < 0.001). Moreover, a higher degree of myopia exhibited a positive effect on knowledge (β = 0.510, P < 0.001). Nurses and other medical staff showed a negative effect on knowledge (β = - 0.706, P < 0.001) compared to doctors. Working in secondary and tertiary public hospitals, as well as private hospitals, demonstrated a negative effect on practice (β = - 1.963, P < 0.001) compared to those working in primary hospitals. Non-ophthalmic medical staff exhibited moderate knowledge, positive attitudes, and moderate practices toward myopia-related fundus lesions. The degree of myopia, doctors vs. other medical staff, and the hospital level influence the KAP of non-ophthalmic medical staff.

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.

Myopia Prevalence in Latin American Children and Adolescents: A Systematic Review and Meta-Analysis

Although myopia is a growing global concern, comprehensive studies on its prevalence among Latin American (LATAM) children and adolescents are still lacking. Thus, we conducted a systematic review and meta-analysis to determine the prevalence of myopia in LATAM children and adolescents aged three to 20. The study conducted a thorough literature search from January 1, 1975, to February 28, 2023, identifying 24 studies on the prevalence of myopia in LATAM that met the inclusion criteria. Quality assessment and standardized data collection were performed. The meta-analysis used a random-effects model due to heterogeneity and calculated prevalence rates. Finally, the analysis of data from 24 eligible studies revealed a myopia prevalence of 8.61% (range 0.80-47.36%, 95% confidence interval (CI): 5.22-13.87%, p < 0.05) among 165,721 LATAM children and adolescents. No significant age-based associations or temporal trends were observed in this study. Studies with non-cycloplegic or objective assessment exhibited a numerically higher, although statistically non-significant, myopia prevalence (10.62%, 95% CI: 4.9-21.6%) compared to studies using cycloplegia (7.17%, 95% CI: 3.40-14.50%). In conclusion, myopia affects approximately one in 11 LATAM children and adolescents. Given the increasing exposure of LATAM youth to known myopia risk factors, such as extensive near-work, online learning, and limited outdoor activities, it is crucial to monitor myopia trends in this region. Further research is imperative to address and prevent myopia in LATAM.

Prevalence of visual impairment and associated factors among primary school children in Ambo Town, Ethiopia, 2021

Background

Visual impairment is a functional limitation of the eye(s) or the visual system manifested as reduced visual acuity. At least 2.2 billion people have visual impairment worldwide, and 90% of people with visual impairment have either preventable or treatable causes with cost-effective interventions.

Objectives

To assess magnitude of visual impairment and associated factors among primary school children in Ambo Town, Ethiopia, in 2021.

Methods

A cross-sectional study was conducted in selected primary schools of Ambo Town. A simple random sampling technique was used to select schools and study participants. Data were collected using an interviewer-administered structured questionnaire and entered into Epidata version 3.1 for analysis by using SPSS version 23. Binary logistic regression was adopted to identify statistically significant factors which were associated with visual impairment. The Hosmer-Lemeshow test was used to evaluate how well the logistic regression model fits to the data.

Results

About 780 out of 838 primary school children were enrolled in the study, yielding a response rate of 93.07%. The estimated prevalence of visual impairment was 8.8% with 95% CI: 6.81-10.79. The main risk factor for visual impairment among primary school children were Students' grade level, exposure to mobile screen, family history of visual problems, and family awareness about the status of their child's eye problems were significantly associated with visual impairments (AOR = 2.375, 95% CI: 1.079-5.226; AOR = 2.44, 95% CI: 1.401-5.01; AOR = 2.41, 95% CI: 1.071-5.42; and AOR = 4.503, 95% CI: 2.12-9.55, respectively).

Conclusion

A high prevalence of visual impairment was observed among primary school children. Attending higher grades, being exposed to mobile screen, and having a family history of visual problems were significantly associated with visual impairment.

Gut Microbiota Profiles in Myopes and Nonmyopes

Purpose

To identify compositional differences in the gut microbiome of nonmyopes (NM) and myopes using 16S ribosomal RNA sequencing and to investigate whether the microbiome may contribute to the onset or progression of the condition.

Methods

Faecal samples were collected from 52 adult participants, of whom 23 were NM, 8 were progressive myopes (PM), and 21 were stable myopes (SM). The composition of the gut microbiota in each group was analysed using 16S ribosomal RNA gene sequencing.

Results

There were no significant differences in alpha and beta diversity between the three groups (NM, PM, and SM). However, the distributions of Bifidobacterium, Bacteroides, Megamonas, Faecalibacterium, Coprococcus, Dorea, Roseburia, and Blautia were significantly higher in the myopes (SM and PM combined) when compared with emmetropes. The myopes exhibited significantly greater abundance of bacteria that are linked to the regulation of dopaminergic signalling, such as Clostridium, Ruminococcus, Bifidobacterium, and Bacteroides. Individuals with stable myopia were found to have a significantly higher proportion of Prevotella copri than those with progressive myopia. Bifidobacterium adolescentis, a gamma-aminobutyric acid (GABA)-producing bacterium, was significantly higher in all myopes than in NM and, in the comparison between SM and PM, it is significantly higher in SM. B. uniformis and B. fragilis, both GABA-producing Bacteroides, were present in relatively high abundance in all myopes and in SM compared with PM, respectively.

Conclusions

The presence of bacteria related to dopamine effect and GABA-producing bacteria in the gut microbiome of myopes may suggest a role of these microorganisms in the onset and progression of myopia.

Analysis of risk factors associated with pre-myopia among primary school students in the Mianyang Science City

Objectives To find out the prevalence rate of pre-myopia among primary school students in the Mianyang Science City Area, analyze its related risk factors, and thus provide a reference for local authorities to formulate policies on the prevention and control of myopia for primary school students. Methods From September to October 2021, Cluster sampling was adopted by our research group to obtain the vision levels of primary school students employing a diopter test in the Science City Area. In addition, questionnaires were distributed to help us find the risk factors associated with pre-myopia. Through the statistical analysis, we identify the main risk factors for pre-myopia and propose appropriate interventions. Results The prevalence rate of pre-myopia among primary school students in the Science City Area was 45.27% (1020/2253), of which 43.82% were boys and 46.92% were girls, with no statistically significant difference in the prevalence rate of myopia between boys and girls (2 =2.171, P=0.141). The results of the linear trend test showed that the prevalence rate of pre-myopia tends to decrease with increasing age (Z=296.521, P=0.000). Logistic regression analysis demonstrated that the main risk factors for pre-myopia were having at least one parent with myopia, spending less than 2 hours a day outdoors, using the eyes continuously for more than 1 hour, looking at electronic screens for more than 2 hours, and having an improper reading and writing posture. Conclusion The Science City Area has a high prevalence rate of pre-myopia among primary school students. It is proposed that students, schools, families, and local authorities work together to increase the time spent outdoors, reduce digital screens and develop scientific use of eye habits.

Associations between body size and visual impairment of first-year university students in Chongqing: A cross-sectional study

The relationship between body size and visual impairment (VI) presents a controversial topic in the health sciences. This study aims to evaluate and clarify the potential associations between these 2 variables. We conducted a cross-sectional study on first-year students enrolled in 2022 at the Southwest University of Political Science & Law. The students underwent a series of physical examinations and visual acuity tests. Visual impairment was classified into 3 categories: mild, moderate, or severe. We used logistic regression analysis to examine the association between body size and VI. Our findings indicated a high prevalence of VI among first-year university students; more than 80% of them were affected. In bivariate analysis, height and weight were negatively related to the presence of VI. However, BMI (body mass index) was not related to VI. By adjusting all available confounders, no associations between BMI (OR = 1.002, 95% CI = 0.974-1.032, P = .877), height (OR = 0.998, 95% CI = 0.967-1.010, P = .298), weight (OR = 0.999, 95% CI = 989-1.009, P = .860), and mild-severe VI were found in females. For males, the ORs were 0.988 (95% CI = 0.955-1.021, P = .459), 0.980 (95% CI = 0.954-1.006, P = .135), and 0.995 (95% CI = 0.985-1.004, P = .285) for BMI, height, and weight, respectively. Among young adults demonstrating high academic performance in high schools, the cessation of physical growth, combined with potential eye strain resulting from overuse, may mitigate any previously observed positive associations between physical status and VI in younger children.

Myopia progression in school children with prolonged screen time during the coronavirus disease confinement

Background

Myopia, the most common refractive error, is a global public health problem with substantial visual impairment if left untreated. Several studies have investigated the association between increased near-work and restricted outdoor activities in children with myopia; however, such studies in children without myopia are scarce. We aimed to monitor the effect of the coronavirus disease-2019 (COVID-19) home confinement and mandatory virtual learning on myopic progression among myopic and non-myopic school-aged children.

Methods

We conducted a retrospective chart review of children aged 6 - 12 years attending regular visits to the pediatric ophthalmology clinic in a tertiary eye hospital in Eastern Province, Saudi Arabia. Cycloplegic refraction was determined from three visits at least six months apart: two visits before the start of the COVID-19 pandemic and one during the COVID-19 home confinement. Parents were asked about the time spent in near-work and outdoor activities, the devices used during virtual learning, and the demographic characteristics of the children. Statistical analyses were conducted to compare myopia progression before and during the COVID-19 home confinement.

Results

A total of 160 eyes of 80 children were analyzed. The boy (n = 46) to girl (n = 34) ratio was 1.4:1. The hyperopia (n = 131 eyes) to myopia (n = 29 eyes) ratio was 4.5:1. Most eyes exhibited a hyperopic shift before the confinement; however, all eyes displayed a myopic shift during the confinement. When comparing both eyes of the same individual, the more myopic or less hyperopic eye in the same child had a significantly greater myopic shift than the fellow eye (both P < 0.05). Children who used tablets showed a significant myopic shift (P < 0.05). Likewise, children in both age categories ( ≤ 8 and > 8 years), boys, those living in an apartment, and those having parents with bachelor's degrees experienced a significant myopic shift during COVID-19 home confinement compared to before (all P < 0.05). The mean myopic shift was greater in children aged > 8 years than in those aged ≤ 8 years. Children with and without a family history of myopia had a myopic shift in the mean spherical equivalent during COVID-19 home confinement; however, that of children with no family history was statistically significant (P < 0.05).

Conclusions

Progression of myopia accelerated in children during the COVID-19 pandemic. Excessive time spent on digital screen devices at near distances is considered a substantial environmental contributor to myopic shift in children. Further multicenter studies with extended follow-up periods are needed to assess the factors contributing to myopic progression in our population.

Prevalence Trend of Myopia during the Post-COVID-19 Epidemic Period among Preschoolers: A Prospective School-based Study

SIGNIFICANCE

Changes in behavior and lifestyle during the post-coronavirus disease 2019 (COVID-19) epidemic may have some impact on myopia rates in preschoolers, and exploring the changes in myopia rates in preschool children may inform the formulation of myopia prevention and control policies.

PURPOSE

This study aimed to investigate the prevalence of myopia in preschool children during the post-COVID-19 epidemic period in Xuzhou, China.

METHODS

A series of cross-sectional school-based studies was conducted. A total of 117,632 preschool children aged 3 to 6 years were subjected to annual vision screening from 2019 to 2021. Spot photo screening was used to record the spherical equivalent refraction for each child and to analyze the prevalence of myopia by age, sex, and region during the post-COVID-19 epidemic period.

RESULTS

A total of 113,979 preschool children were included in the analysis, of whom 60,784 (53.3%) were male and 53,195 (46.7%) were female. For all children, the mean ± standard deviation spherical equivalent refraction in 2019, 2020, and 2021 was +0.32 ± 0.50, +0.34 ± 0.55, and +0.34 ± 0.54 D, respectively (all P < .05), indicative of a very slight hyperopic shift. In all age groups, the change in mean spherical equivalent refraction and its distribution were relatively stable. From 2019 to 2021, the overall prevalence of myopia in preschool children was 3.1, 3.3, and 3.5%, respectively. The rise in myopia rates was minimal. The largest increase in the annual prevalence of myopia was seen among children aged 6 years, at 0.5%, followed by those aged 5 years (0.4%) and aged 3 years (0.4%). The prevalence was higher in boys than girls and in urban versus rural areas.

CONCLUSIONS

During the post-COVID-19 epidemic period, the refractive status of Xuzhou preschool children remained stable.

The Role of Retinal Dysfunction in Myopia Development

Myopia is a refractive disorder arising from a mismatch between refractive power and relatively long axial length of the eye. With its dramatically increasing prevalence, myopia has become a pervasive social problem. It is commonly accepted that abnormal visual input acts as an initiating factor of myopia. As the first station to perceive visual signals, the retina plays an important role in myopia etiology. The retina is a fine-layered structure with multitudinous cells, processing intricate visual signals via numerous molecular pathways. Accordingly, dopaminergic mechanisms, contributions of rod and cone photoreceptors, myopic structural changes of retinal pigment epithelium (RPE) and neuro-retinal layers have all suggested a vital role of retinal dysfunction in myopia development. Herein, we separately discuss myopia-related retinal dysfunction and current dilemmas by different levels, from molecules to cells, with the hope that the comprehensive delineation could contribute to a better understanding of myopia etiology, indicate novel therapeutic targets, and inspire future studies.

High Myopia and Thickness of Extraocular and Masticatory Muscles-7T MRI, Preliminary Study

(1) Background: Myopia is one of the most common refractive errors in the world. The aim of this study was to evaluate the transverse dimensions of selected masticatory muscles (temporalis muscle and masseter muscle) versus the transverse dimensions of selected extraocular muscles (superior rectus, inferior rectus, medial rectus and lateral rectus) in emmetropic and high myopic subjects. (2) Methods: Twenty-seven individuals were included in the analysis, resulting in 24 eyeballs of patients with high myopia and 30 eyeballs of emmetropic subjects. A 7 Tesla resonance was used to analyze the described muscles. (3) Results: Statistical analysis showed differences in all analyzed extraocular muscles and all analyzed masticatory muscles between emmetropic subjects and high myopic subjects. In the high myopic subject group, statistical analysis showed four correlations. The three negative correlations were between the lateral rectus muscle and an axial length eyeball, refractive error and an axial length eyeball, and the inferior rectus muscle and visual acuity. The positive correlation was between the lateral rectus muscle and the medial rectus muscle. (4) Conclusions: The high myopic subjects are characterized by a larger cross-sectional area of extraocular muscles and masticatory muscles compared to the emmetropic subjects. Correlations were observed between the thickness of the extraocular muscles and the masticatory muscles. The lateral rectus muscle was related to the length of the eyeball. The phenomenon requires further study.

The Prevalence of Myopia Among Primary School Male Students in Bisha, Saudi Arabia

Background Myopia (shortsightedness) is considered a major health problem globally which has increased in the last few decades. This study aims to determine the prevalence of myopia and the associated risk factors among primary school students in Bisha, Saudi Arabia. Methods This descriptive cross-sectional study included 330 male students from five boys' schools in Bisha city. Students underwent an interview questionnaire that composed of (sociodemographic data, risk factors, and ocular history). Students' vision was assessed by an optometrist through the use of a Snellen chart and the result was converted to a Diopter unit (D). Myopia was defined as the spherical equivalent (SE) of ≤ - 0.5 D. Binomial statistical test was used to get a prevalence of myopia with a confidence interval (CI) of 95%. Chi-square analytical test was used to compare myopic and non-myopic groups on multiple variables. Results were considered statistically significant at p-value ≤ 0.05. Results The mean age of 330 male students was 11.29 ± 0.97. The prevalence of myopia was (32.7%, 95% CI: 27.7-38.1%), and the mean of the SE of participants was - 0.25 ± 0.60 D. Myopia prevalence was increased with age and school grade of participants (p ≤ 0.05). Students who spent a long time (more than three hours) on near activity are at risk of developing myopia (p ≤ 0.001). having one or both parents affected by myopia was not statistically significant with the prevalence of myopia (p = 0.175). Children who spent a long time outdoors tend to have a lower risk of myopia (p ≤ 0.001). Conclusion The study showed a high prevalence of myopia among schoolchildren in Bisha city. Therefore, it is recommended to plan for future screening programs for myopia.

MicroRNA Expression in Subretinal Fluid in Eyes Affected by Rhegmatogenous Retinal Detachment

Proliferative vitreoretinopathy (PVR) is an abnormal intraocular scarring process that can complicate cases of rhegmatogenous retinal detachment (RRD). Although previous studies have examined the relevance of microRNAs (miRNAs) in ophthalmic diseases, only a few studies have evaluated the expression profiles of microRNAs in subretinal fluid. We hypothesized that the expression profiles of specific miRNAs may change in response to RRD, in the subretinal fluid that is directly in contact with photoreceptors and the retinal pigment epithelium (RPE). We looked for a potential correlation between the expression of specific miRNAs in eyes with RRD and known clinical risk factors of PVR. A total of 24 patients (59 ± 11 years) who underwent scleral buckling procedure were enrolled in this prospective study. Twenty-four undiluted subretinal fluid samples were collected, RNA was isolated and qRT-PCR was performed to analyze the expression of 12 miRNAs. We found the existence of a positive association between the expression of miR-21 (p = 0.017, r = 0.515) and miR-34 (p = 0.030, r = 0.624) and the duration of symptoms related to retinal detachment. Moreover, the expression of miR-146a tended to decrease in patients who developed PVR. Subretinal fluid constitutes an intriguing biological matrix to evaluate the role of miRNAs leading to the development of PVR.

Effects of Greenness on Myopia Risk and School-Level Myopia Prevalence Among High School-Aged Adolescents: Cross-sectional Study

BACKGROUND

Myopia is a serious public health issue. High school-aged adolescents in Beijing have an alarming prevalence of myopia. Therefore, determining myopia protective factors is essential. Green space has a certain association with myopia protective factors that can protect against myopia.

OBJECTIVE

This study aims to examine the effects of green space around schools on individual myopia risk in high school-aged adolescents and the school-level myopia prevalence.

METHODS

Green space was measured using the normalized difference vegetation index (NDVI). A total of 13,380 samples of 51 high schools were selected from a 2021 Beijing Municipal Health Commission survey. Adolescent myopia was defined as a spherical equivalent of ≤-1.00 diopters in the worse eye. Generalized linear mixed models with a binomial error structure were used to analyze the effects of the NDVI on personal myopia risk and adjust them by other factors, such as demographics, exposure time, and outdoor exercise. The effects of the NDVI on school-level myopia prevalence with adjusted demographics and the relative position factors of trees were analyzed through quasibinomial regression.

RESULTS

The overall prevalence of myopia was 80.61% (10,785/13,380, 95% CI 79.93%-81.27%). Although with a 0.1 increase in the 500 and 1000 m buffer NDVIs adjusted by demographic and other factors, the high school-aged personal myopia risk significantly dropped by 16% (odds ratio [OR] 0.84, 95% CI 0.73-0.97) and 12% (OR 0.88, 95% CI 0.79-0.99), respectively. However, only the adjusted 500 m buffer NDVI (by demographics and the position of trees) with a 0.1 increase significantly reduced the school-level myopia prevalence by 15% (OR 0.85, 95% CI 0.74-0.98). Subgroup analysis showed that the adjusted effects of the 500 m buffer NDVI are significant in schoolgirls (OR 0.82, 95% CI 0.72-0.93), juniors (OR 0.82, 95% CI 0.72-0.94), the Han nationality (OR 0.84, 95% CI 0.72-0.97), 1-year exposure (OR 0.84, 95% CI 0.71-0.99) and 3-year exposure (OR 0.78, 95% CI 0.65-0.94).

CONCLUSIONS

The greenness of a 500 m buffer around schools is associated with a lower personal myopia risk among adolescents and a lower prevalence of myopia in schools. With regard to prevention and control activities, green space within a 500 m buffer around schools is suggested as an independent protective factor for adolescent myopia.

A Review of the Role of the School Spatial Environment in Promoting the Visual Health of Minors

Rising childhood myopia rate has detrimental health consequences that pose a considerable challenge to health systems. The school spatial environment, which is where students are for the longest period of time, has a high health value for myopia systematic intervention. While research has demonstrated associations between physical daylight environments, medical gene and visual health, the literature currently lacks a synthesis of evidence that will act as a spatially-organized resource for school designers. This study is based on literature from the period 2000-2022 and has been taken from the Web of Science, scopus, Medline and CNKI core collection database. Collaboration, literature co-citation and quantitative and qualitative analysis, in addition to keyword co-occurrence are adopted to conduct a visual health research review. The results indicate that intensive near work activity (as a risk factor) and longer time spent outdoors (as a protective factor), are involved in visual health factors. Two main research themes are obtained and relate to: (1) The environment of visual work behavior (especially the near work learning environment) and adaptable multimedia learning environment; and (2) the environment of outdoor exposure behavior. Furthermore, with the variation of educational demands, models and concepts, there are different demands for near work behavior, and this study makes an important contribution by pointing to two future research directions, including the accurate and controllable environment of near work behavior, which operate in accordance with various educational mode requirements and the active design of the environment of outdoor exposure behavior. In referring to differences between regions and countries, as well as the development of the educational environment, it provides insight into how these demands can be controlled.

Macular function in patients with medium myopia

Purpose

This work aims at assessing whether electrophysiological functional changes in the macular region appear in medium myopia, even in the presence of a normal macular OCT scan and how axial length correlates with macular OCT parameters in medium myopia.

Methods

The study included right eyes of 17 patients with myopia of medium degree (SE <  − 6D to >  − 3D). Control group consisted of 20 eyes of patients of age and sex that matched healthy controls with normal macular and optic nerve OCT results and normal axial length. Full ophthalmic examination (the distance best-corrected visual acuity, intraocular pressure, refractive error, the anterior and posterior segment of the eye in a slit lamp, the axial length of the eyeball) with OCT of the macular and optic disk and the PERG test were performed in the study and control groups. Only the patients with normal ophthalmic and OCT examination results were qualified. The interview covering questions on risk factors of myopia onset and progression such as prematurity, family history of myopia was carried out in both groups. In myopic group, the question relating to time of near work was also asked. Study and control groups were tested with the use of Shapiro–Wilk, Mann–Whitney, Student’s t test, Pearson and Spearman's rank correlation tests.

Results

AL was significantly longer in myopia group (p < 0.01), and SE value was lower (p < 0.01). Longer implicit time of P50 was found in the study group, but amplitudes of P50 and N95 waves were not significantly reduced (p < 0.05). AL showed correlations with P50 implicit time (p < 0.05) and with reduction in retinal fiber nerve layer and ganglion cells and inner plexus layer (p < 0.05).

Conclusion

Patients with myopia of medium degree have a dysfunction of retinal cone system of the macular region even when OCT scans show no abnormalities. Elongation of AL correlates with reduction in retinal fiber nerve layer and ganglion cells and inner plexus layer. Longitudinal follow-up studies may answer the question whether this increase in implicit time may be indicative of a faster myopia progression or of myopic retinal pathology, i.e., whether it may help to determine which patient would benefit from earlier or more intensive management of myopia progression.

The contribution of intraocular lens calculation accuracy to the refractive error predicted at 10 years in the Infant Aphakia Treatment Study

PURPOSE

To determine the relative contribution of intraocular lens (IOL) calculation accuracy and ocular growth variability to the long-term refractive error predicted following pediatric cataract surgery.

METHODS

Pseudophakic eyes of children enrolled in the Infant Aphakia Treatment Study (IATS) were included in this study. Initial absolute prediction error (APE) and 10-year APE were calculated using the initial biometry, IOL parameters, postoperative refractions, and mean rate of refractive growth. The cohort was divided into children with a low-initial APE (≤1.0 D) and a high-initial APE ( >1.0 D). The 10-year APE was compared between the two groups using the Mann-Whitney U test. Linear regression was used to estimate the variability in prediction error explained by the initial IOL calculation accuracy.

RESULTS

Forty-two children with IOL placement in infancy were included. Seventeen eyes had a low initial APE, and 25 eyes had a high initial APE. There was no significant difference in APE 10 years following surgery between individuals with a low initial APE (median, 2.67 D; IQR, 1.61-4.12 D) and a high initial APE (median, 3.45 D; IQR, 1.64-5.10 D) (P = 0.7). Initial prediction error could explain 12% of the variability in the prediction error 10 years following surgery.

CONCLUSIONS

IOL calculation accuracy contributed minimally to the refractive error predicted 10 years after cataract surgery in the setting of high variability in the rate of refractive growth.

The Prevalence and Progression of Myopia in Elementary School Students in Shanxi Province, China During the COVID-19 Pandemic

PURPOSE

To investigate the prevalence of myopia and the risk factors associated with its progression in elementary school students during the COVID-19 pandemic in Shanxi Province, China.

METHODS

The investigation included 960 students spanning first to sixth grade from six elementary schools in Shanxi Province, China. All participants received non-cycloplegic refraction and vision tests in December of 2019 (before the COVID-19 pandemic) and in June of 2020 (after classes resumed). Information concerning the students' eye-use behaviors, physical activities, diet and sleep during the pandemic was collected using a questionnaire survey. A total of 913 students (457 males) completed all tests and the questionnaire.

RESULTS

The overall prevalence rate of myopia was 16.6% in December of 2019, and it increased with age. There was no gender difference in the prevalence of myopia (χ² = 3.210, P = .073), but females exhibited a lower average spherical equivalent (SE) (P = .026). When the classes were resumed 6 months later, the overall prevalence rate of myopia was found to be 39.4%, which was significantly higher than it before the pandemic (χ² = 117.425, P < .001). The average SE of the participants was -0.95D, which was significantly lower than the average SE (-0.43D) before the pandemic (P < .001). SE variation (ΔSE) in grade 6 was significantly higher than that in grade 1. No significant difference in ΔSE was found between males and females. Analyses of ordinary least squares (OLS)-estimated linear, natural logarithmic and quadratic functions revealed that the progression of myopia during the COVID-19 pandemic was significantly correlated with screen time, types of electronic devices, the amount of sleep, age, and the number of parents with myopia.

CONCLUSIONS

The prevalence rate and progression of myopia among elementary school students in Shanxi Province increased significantly during the COVID-19 pandemic, which was likely related to China's home-based online learning programs. Therefore, it is necessary to optimize the educational programs for elementary school students when they study at home. We recommend increased time for outdoor activities and limiting screen time.

Candidate pathways for retina to scleral signaling in refractive eye growth

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

Systematic review and meta-analysis of myopia prevalence in African school children

Purpose

Increased prevalence of myopia is a major public health challenge worldwide, including in Africa. While previous studies have shown an increasing prevalence in Africa, there is no collective review of evidence on the magnitude of myopia in African school children. Hence, this study reviews the evidence and provides a meta-analysis of the prevalence of myopia in African school children.

Methods

This review was conducted using the 2020 Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Five computerized bibliographic databases, PUBMED, Scopus, Web of Science, ProQuest, and Africa Index Medicus were searched for published studies on the prevalence of myopia in Africa from 1 January 2000 to 18 August 2021. Studies were assessed for methodological quality. Data were gathered by gender, age and refraction technique and standardized to the definition of myopia as refractive error ≥ 0.50 diopter. A meta-analysis was conducted to estimate the prevalence. Significant heterogeneity was detected among the various studies (I² >50%), hence a random effect model was used, and sensitivity analysis was performed to examine the effects of outliers.

Results

We included data from 24 quality assessed studies, covering 36,395 African children. The overall crude prevalence of myopia over the last two decades is 4.7% (95% CI, 3.9–5.7) in African children. Although the prevalence of myopia was slightly higher in females (5.3%, 95%CI: 4.1, 6.5) than in males (3.7%, 95% CI, 2.6–4.7; p = 0.297) and higher in older [12–18 years 5.1% (95% CI, 3.8–6.3) than younger children (aged 5–11 years, 3.4%, 95% CI, 2.5–4.4; p = 0.091), the differences were not significant. There was a significantly lower prevalence of myopia with cycloplegic compared with non-cycloplegic refraction [4.2%, 95%CI: 3.3, 5.1 versus 6.4%, 95%CI: 4.4, 8.4; p = 0.046].

Conclusions

Our results showed that myopia affects about one in twenty African schoolchildren, and it is overestimated in non-cycloplegic refraction. Clinical interventions to reduce the prevalence of myopia in the region should target females, and school children who are aged 12–18 years.

Risk Factors for Myopia in 2 Hong Kong School Systems: A Pilot Study

PURPOSE

Myopia has reached "epidemic" proportions, especially in several East Asian countries. Most myopia emerges during childhood, particularly during the school years. The aim of this study was to investigate myopia prevalence and compare risk factors of myopia among Hong Kong Chinese primary school children under 2 different educational systems.

DESIGN

Cross-sectional study.

METHODS

Visual assessments were conducted in 1 government-funded primary school (n = 159) and 1 international school (n = 223) in Hong Kong in September and October 2018, respectively. Measurements were performed on children aged 8 to 10 years old. Noncycloplegic refraction and axial length were measured, respectively. A validated questionnaire focusing on demographic information, nonscreen time (eg, reading and writing on paper materials), screen time (ie, smartphones and tablets usage), time spent on outdoor activities, and other myopia risk factors was completed by parents of participants.

RESULTS

The prevalence of myopia [37.5% vs 12.8%, P < 0.001; spherical equivalent refraction (SER) ≤ -1.00 diopter (D)] and refractive astigmatism [25.0% vs 7.2%, P < 0.001; cylinder (Cyl) ≥ 1.00 diopter cylinder (DC)] were significantly higher in the local school than in the international school. Students in the local school were slightly older than those attending the international school (9.17 ± 0.82 years vs 8.95 ± 0.85 years, P = 0.046), and there was no significant difference in gender distribution between the 2 schools (P = 0.51). There were significant differences in the demographic information including parental myopia (P < 0.001), family income (P < 0.001), and parents' educational level (P < 0.001) between the 2 schools. Multiple regression analysis showed that parental myopia history and continuous near work was associated with myopia in the local school, while the father's educational level was related to myopia in the international school.

CONCLUSIONS

In this pilot study, despite the much higher prevalence of parental myopia and high myopia in the international school, the myopia prevalence among the students is lower in this school than in the local school, suggesting that environmental factors other than genetics might have a stronger protective effect in this school population.

MicroRNA-29a May Influence Myopia Development by Regulating Collagen I

PURPOSE

The aim of this study was to characterize the regulatory role of microRNA-29a (miR-29a) in myopia, providing support for potential biomarkers and new therapeutic targets of myopia in humans.

METHODS

The miR-29a expression level was detected in the aqueous humor and peripheral blood plasma of 21 high myopic patients and eight cataract control patients using quantitative polymerase chain reaction. iTRAQ analysis of proteomes was conducted to show the regulatory effect of miR-29a on human scleral fibroblasts (SFs) cultured in vitro. We also assessed proliferation, migration, and collagen I synthesis in SF cells, mediated by miR-29a.

RESULTS

MiR-29a expression was significantly higher in the aqueous humor of highly myopic patients than in the cataract control patients (fold change: 4.861, p = 0.001). miR-29a inhibited the synthesis of type I collagen in human SF cells and enhanced cell migration, but had no significant effect on cell proliferation.

CONCLUSION

MiR-29a was highly expressed in aqueous humor of myopia patients and inhibited the synthesis of type I collagen in human SF cells in vivo, thereby it may play an important role in myopia development.

Effect of School-Based Family Health Education via Social Media on Children's Myopia and Parents' Awareness: A Randomized Clinical Trial

Importance

Myopia is a common cause of vision loss, and its prevalence is increasing globally.

Objective

To evaluate the effects of school-based family health education via WeChat in raising parents' awareness of myopia prevention and behavior and in controlling the development of myopia in children.

Design, Setting, and Participants

A single-masked cluster randomized clinical trial of children was conducted from October 1, 2018, to December 31, 2020, among grade 1 students from 12 primary schools in Guangzhou, China. The 12 primary schools were randomly selected in 2 districts and randomized to the intervention and control groups. All grade 1 students were invited to participate, and 688 students were included in the intervention group and 752 in the control group.

Interventions

Weekly health education via the social media platform WeChat was provided to the parents in the intervention group.

Main Outcomes and Measures

Data include results of eye examinations of children and questionnaires completed by parents. The primary outcome was the 2-year cumulative incidence rate of myopia. Myopia was defined as a spherical equivalent (SE) refractive error (sphere of +0.5 cylinder) of at least -0.50 diopters (D). The secondary outcomes were the 2-year changes in the axis length and SE refraction, parental awareness, children's screen time, outdoor activities, and learning tools during COVID-19.

Results

Among the 1525 children included at baseline (835 boys [54.8%]; mean [SD] age, 6.3 [0.5] years), 1244 competed the final assessment; the 2-year cumulative incidence rate of myopia was 106 of 544 (19.5%) in the intervention group and 171 of 700 (24.4%) in the control group (difference, 4.9% [95% CI, 0.3%-9.5%]; P = .04). The mean myopic shift in SE refraction in the intervention group (-0.82 D) was lower than that in the control group (-0.96 D; difference, -0.14 [95% CI, -0.22 to -0.06] D; P < .001). No difference in change in axial length was detected (difference, 0.02 [95% CI, -0.06 to 0.09] mm; P = .70).

Conclusions and Relevance

School-based weekly family health education via WeChat resulted in a small decrease in the 2-year cumulative incidence rate of myopia with a difference in SE of less than 0.25 D not accompanied by any axial length differences. Whether these findings extrapolate elsewhere in the world or are clinically relevant in the short or long term remain to be determined.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR1900022236.

Comparison between estimated and measured myopia progression in Hong Kong children without myopia control intervention

Purpose

To compare myopia progression estimated by the Brien Holden Vision Institute (BHVI) Myopia Calculator with cycloplegic measures in Hong Kong children wearing single‐vision distance spectacles over a 1‐ and 2‐year period.

Methods

Baseline age, spherical equivalent refraction (SER) and ethnicity of control participants from previous longitudinal myopia studies were input into the BHVI Myopia Calculator to generate an estimate of the SER at 1 and 2 years. Differences between the measured and estimated SER (116 and 100 participants with 1‐ and 2‐year subjective refraction data, respectively, and 111 and 95 participants with 1‐ and 2‐year objective refraction, respectively) were analysed, and the measured SER compared with the 95% confidence interval (CI) of the estimated SER.

Results

In children aged 7–13 years, 36% progressed within the 95% CI of the Myopia Calculator's estimate, whereas 33% became less myopic than predicted (range 0.31 to 1.92 D less at 2 years) and 31% became more myopic than predicted (range 0.25 to 2.33 D more myopic at 2 years). The average difference between the estimated and measured subjective or objective SER at 1 and 2 years of follow‐up was not clinically significant (<0.25 D).

Conclusions

On average, the BHVI Myopia Calculator estimated SER was in close agreement with measured cycloplegic SER after 1 and 2 years of follow‐up (mean differences < 0.25 D). However, the measured myopia progression only fell within the 95% CI of the estimated SER for 32%–38% of children, suggesting that the BHVI ‘without management’ progression data should be interpreted with caution. The inclusion of additional data, modified to include axial elongation, from longitudinal studies of longer duration with larger sample sizes and a range of racial backgrounds may improve the Calculator's ability to predict future myopia progression for individual children.

The relationship between serum zinc levels and myopia

CLINICAL SIGNIFICANCE

Nutritional status influences growth and development, including that of the eye. However, little attention has been given to possible dietary influences in myopia. This study demonstrates that serum zinc has no relationship with myopia development.

BACKGROUND

Myopia is inherently associated with eye growth and thereby possibly amenable to nutritional influence. A number of Asian studies have reported lower levels of serum zinc in myopic children. This study was designed to assess the relationship between serum zinc and myopia in the Korean population - using a subsample of participants from nationally representative data.

METHODS

Data from the fifth Korea National Health and Nutrition Examination Survey (KNHANES) 2010 were used to explore zinc status in relation to refraction. A total of 304 participants were analysed, ranging in age from 12 to 19-years. Serum zinc levels were measured using inductively coupled plasma mass spectrometry, while refractive error was determined by non-cycloplegic autorefraction. Multivariate analysis was used to examine the association.

RESULTS

A significant majority of participants (n = 255; 84 per cent) were myopic. There was no significant difference in serum zinc levels between myopic and non-myopic children (p = 0.81). In multivariate logistic regression, serum zinc was not significantly associated with myopia after adjustment for age, gender, residence, body mass index, family income and recreational activity. Similarly, no relationship was observed between spherical equivalent refraction and serum zinc within the myopic group (p = 0.46).

CONCLUSION

In a subset of 12-19-year-old participants from the population-representative KNHANES study, no association was found between serum zinc and myopia. However, the lack of a sensitive biomarker for zinc status remains a major limitation in this, and all current studies.

Influence of the interaction between parental myopia and poor eye habits when reading and writing and poor reading posture on prevalence of myopia in school students in Urumqi, China

Background

To evaluate the prevalence of myopia in school students in Urumqi, China, and explore the influence of the interaction between parental myopia and poor reading and writing habits on myopia to identify the at-risk population and provide evidence to help school students avoid developing myopia.

Methods

A cross-sectional survey was conducted with 6,883 school students aged 7–20 years in Urumqi in December 2019. The Standard Eye Chart and mydriatic optometry were used to determine whether students had myopia. Falconer’s method was used to calculate the heritability of parental myopia. Multivariate unconditional logistic regression models were used to analyze the risk factors for myopia and the additive and multiplicative interaction of parental myopia and poor reading and writing habits.

Results

After standardizing the age of the 6,883 students, the overall prevalence rate of myopia was 47.50 %. The heritability of parental myopia was 66.57 % for boys, 67.82 % for girls, 65.02 % for the Han group, and 52.71 % for other ethnicities. There were additive interactions between parental myopia and poor reading and writing habits; among them, parental myopia and poor eye habits when reading and writing (the distance between the eyes and book is less than 30 cm when reading and writing, fingers block the sight of one eye while holding the pen, and leaning one’s body when reading and writing; habit 1) increased the risk of myopia by 10.99 times (odds ratio [OR] = 10.99, 95 % confidence interval [CI] = 8.33–14.68), parental myopia and poor reading posture (reading while lying down, walking, or in the car; habit 2) increased the risk of myopia by 5.92 times (OR = 5.92, 95 % CI = 4.84–7.27). There was no multiplicative interaction between parental myopia and habit 1 or habit 2 (OR = 0.69, 95 % CI = 0.44–1.08; OR = 0.89, 95 % CI = 0.66–1.21, respectively).

Conclusion

The prevalence of myopia among students in Urumqi, Xinjiang is relatively high. The risk of developing myopia is affected by parental myopia and poor reading and writing habits. In addition, parental myopia amplifies the harm caused by poor reading and writing habits, thereby increasing the risk of myopia. Students with parents who have myopia should be targeted during myopia prevention efforts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02058-3.

Prevalence of Refractive Errors among Children in Saudi Arabia: A Systemic Review

Introduction:

The aim of this review was to estimate the prevalence of refractive errors (RE) and uncorrected refractive error (URE) in school-aged children of 4 to 14 years of age in Saudi Arabia.

Methods:

An extensive search was performed for peer-reviewed studies with data from the Saudi population during the past 20 years. The Cochrane Library, Pubmed, and Embase databases were used. Two independent reviewers evaluated publications and extracted the data. The quality of the studies was evaluated based on a critical appraisal tool designed for systematic reviews. The pooled prevalence of refractive error, uncorrected refractive error and different types of refractive error were estimated by using the random-effects meta-analysis.

Results and Discussion:

Eight school-based studies were included in this review. Among the overall pooled population of 12,247childern, the estimated prevalence of refractive error was 17.5% (95% CI: 11.1- 25). In the five studies that reported uncorrected refractive error (N=10,198), the pooled prevalence was 16.8% (95% CI: 11.4 – 21.3). The overall prevalence of refractive errors was very similar among boys, 16.8 (95% CI: 10.8- 24.1), and girls, 17.7% (95% CI: 10.2 – 25.9). Myopia was the most prevalent refractive error and was present in 40.8% (95% CI: 16.1 – 69.9) followed by astigmatism 29.7% (95% CI: 6.1- 61.7) and hyperopia 28.3% (95% CI: 16.9 – 41.2).

Conclusion:

This review highlights the high prevalence of refractive errors and uncorrected refractive error among children in Saudi Arabia. More studies are required using standardised methods in different regions where there is a lack of information on UREs. It is recommended that vision screening programs of children for RE should be implemented at the community level and integrated into school health programmes in order to detect UREs and prevent amblyopia, which is one of the debilitating consequences of URE.

PI3K/AKT/mTOR signaling participates in insulin-mediated regulation of pathological myopia-related factors in retinal pigment epithelial cells

BACKGROUND

Insulin positively correlates with the length of the eye axis and is increased in the vitreous and serum of patients with pathological myopia (PM). How insulin influences the physiological process of retinal pigment epithelial (RPE) cells in PM remains unclear. This study aimed to explore the effect of insulin on the ultrastructure and function of RPE cells and the role of PI3K/AKT/mTOR signaling involved in the development of PM.

METHODS

The ARPE-19 cells were treated with different concentrations of insulin to analyze the cell morphology, cell viability, the protein level of insulin receptor β, and the mRNA and protein levels of and PM-related factors (TIMP-2, MMP-2, bFGF, and IGF-1). The ultrastructure of APRE-19 cells was also observed after insulin treatment. Besides, the PI3K/AKT/mTOR signaling was studied with or without the PI3K inhibitor LY294002 in ARPE-19 cells.

RESULTS

Insulin enhanced the cell viability of ARPE-19 cells and caused the endoplasmic reticulum to expand and vesiculate, suggesting increased secretion of growth factors and degeneration in ARPE-19 cells. Furthermore, the insulin receptor β was stimulated with insulin treatment, subsequently, the phosphorylation of AKT and mTOR was positively activated, which was adversely suppressed in the presence of LY294002. The secretion of TIMP-2 and bFGF was significantly decreased, and the secretion of MMP-2 and IGF-1 was highly elevated with insulin treatment depending on the concentration in ARPE-19 cells. Furthermore, the effect of insulin on PM-related proteins was restored with the addition of LY294002.

CONCLUSIONS

Our results indicated that insulin regulated the secretion of PM-related factors via the PI3K/AKT/mTOR signaling pathway in retinal pigment epithelial cells, and thus probably promoted the development of PM through transducing regulation signals from retina to choroid and sclera.

Nutritional Factors and Myopia: An Analysis of National Health and Nutrition Examination Survey Data

SIGNIFICANCE

The rise in the prevalence of myopia, a significant worldwide public health concern, has been too rapid to be explained by genetic factors alone and thus suggests environmental influences.

PURPOSE

Relatively little attention has been paid to the possible role of nutrition in myopia. The availability of the large National Health and Nutrition Examination Survey data set, which includes results from vision examinations, offers the opportunity to investigate the relationship between several nutrition-related factors, including body metrics, and the presence and magnitude of myopia.

METHODS

Cross-sectional survey data sets with vision examination, demographic, body metrics, and nutritional data, collected as part of the National Health and Nutrition Examination Survey over the years of 2003 to 2008, were extracted for analysis. Based on already published basic and epidemiological studies, the following parameters were selected for study: body height and body mass index, demographics, serum vitamin D and glucose/insulin levels, and caffeine intake, using multivariable models and objectively measured refractive errors as the main outcome measure.

RESULTS

Data from a total of 6855 ethnically diverse Americans aged 12 to 25 years were analyzed. In final multivariate models, female sex and age were the most significant factors related to myopia status and refractive error. In general, body metrics (body mass index) or nutritional factors (serum vitamin D, glucose levels, and caffeine intake) were found to be associated with refractive error or myopia status; however, increased insulin levels were related to increased odds of having myopia.

CONCLUSIONS

These largely negative findings suggest that other environmental factors, such as those related to the visual environment, may contribute more to the development and/or progression of myopia and would argue for continued research in these areas in support of more evidence-based myopia clinical management.

Survey on the Progression of Myopia in Children and Adolescents in Chongqing During COVID-19 Pandemic

Background: The Covid-19 pandemic restricts children and adolescents from doing normal daily activities such as playing outdoors and going to school. The incidence and prevalence of myopia have increased during the COVID-19 pandemic. The aim of this study was to investigate and evaluate the impact of the home confinement during the COVID-19 pandemic on the progression of myopia among children and adolescents in Chongqing, China. Methods: The survey was conducted by using stratified samplings. Samples were randomly selected from the 2019 National Student Physique and Health Survey database, and their visual function and refractive data were compared with those in 2020. Vision-related behavior questionnaire including digital screen exposure was applied to investigate the correlation between eye parameter and eye health-related behavior. Results: A total of 1,733 and 1,728 students were enrolled in 2020 and 2019, respectively. The percentage of myopia students was 55.02% in 2020, which was higher than that in 2019 (44.62%). The mean uncorrected visual acuity (UCVA, LogMAR, 0.35 ± 0.42) in 2020 was higher than that in 2019 (0.27 ± 0.36, P < 0.001). The mean spherical equivalent (SE) refraction (-1.94 ± 2.13 D) in 2020 was lower than that in 2019 (-1.64 ± 5.49 D, P < 0.001). For students who used digital devices for online courses, the mean SE in the television group (-1.10 ± 1.49 D) was better than that in the computer group (-2.03 ± 2.37 D, P = 0.0017) and in the cell phone group (-2.02 ± 2.09 D, P = 0.0028). The average duration of online classes (r = -0.27, P < 0.0001), the number of online classes per day (r = -0.33, P < 0.0001), as well as digital screen exposure time (r = -0.20, P < 0.0001) were negatively correlated with SE, and the average time of outdoor activity (r = 0.20, P < 0.0001) was positively correlated with SE. Conclusions: Increased digital screen exposure contributes to myopic progression in children and adolescents of Chongqing during the COVID-19 pandemic. Suitable digital devices should be provided for online classes and outdoor activity should be advocated to prevent myopic pandemic.

Effect of Education on Myopia: Evidence from the United Kingdom ROSLA 1972 Reform

Purpose

Cross-sectional and longitudinal studies have consistently reported an association between education and myopia. However, conventional observational studies are at risk of bias due to confounding by factors such as socioeconomic position and parental educational attainment. The current study aimed to estimate the causal effect of education on refractive error using regression discontinuity analysis.

Methods

Regression discontinuity analysis was applied to assess the influence on refractive error of the raising of the school leaving age (ROSLA) from 15 to 16 years introduced in England and Wales in 1972. For comparison, a conventional ordinary least squares (OLS) analysis was performed. The analysis sample comprised 21,548 UK Biobank participants born in a nine-year interval centered on September 1957, the date of birth of those first affected by ROSLA.

Results

In OLS analysis, the ROSLA 1972 reform was associated with a -0.29 D (95% confidence interval [CI]: -0.36 to -0.21, P < 0.001) more negative refractive error. In other words, the refractive error of the study sample became more negative by -0.29 D during the transition from a minimum school leaving age of 15 to 16 years of age. Regression discontinuity analysis estimated the causal effect of the ROSLA 1972 reform on refractive error as -0.77 D (95% CI: -1.53 to -0.02, P = 0.04).

Conclusions

Additional compulsory schooling due to the ROSLA 1972 reform was associated with a more negative refractive error, providing additional support for a causal relationship between education and myopia.

Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children

Clinical relevance: Investigation of refractive errors amongst Swedish schoolchildren will help identify risk factors associated with myopia development.Background: Genetic and hereditary aspects have been linked with the development of myopia. Nevertheless, in the case of 'school myopia' some authors suggest that environmental factors may affect gene expression, causing school myopia to soar. Additional understanding about which environmental factors play a relevant role can be gained by studying refractive errors in countries like Sweden, where prevalence of myopia is expected to be low.Methods: Swedish schoolchildren aged 8-16 years were invited to participate. Participants underwent an eye examination, including cycloplegic refraction and axial length (AL) measurements. Predictors such as time spent in near work, outdoor activities and parental myopia were obtained using a questionnaire. Myopia was defined as spherical equivalent refraction (SER) ≤ -0.50D and hyperopia as SER ≥ +0.75D.Results: A total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD = 2.4). Based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95 = 38.8-56.7), emmetropia 42.0% (CI95 = 33.5-51.2) and myopia 10.0%. (CI95 = 4.4-14.9). The mean AL was 23.1 mm (SD = 0.86), there was a correlation between SER and AL, r = -0.65 (p < 0.001). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. The mean time spent in near work, outside of school, was 5.3 hours-per-day (SD = 3.1), and mean outdoor time reported was 2.6 hours-per-day (SD = 2.2) for all the participants. The time spent in near work and outdoor time were different for different refractive error categories.Conclusion: The prevalence of myopia amongst Swedish schoolchildren is low. Hereditary and environmental factors are associated with refractive error categories. Further studies with this sample are warranted to investigate how refractive errors and environmental factors interact over time.

Dual-angle open field wavefront sensor for simultaneous measurements of the central and peripheral human eye

We have developed a novel dual-angle open field wavefront sensor. This device captures real-time foveal and peripheral Zernike aberrations, while providing natural binocular viewing conditions for the subjects. The simultaneous data recording enables accurate analysis of changes in ocular optics with accommodation overcoming any uncertainties caused by accommodative lag or lead. The instrument will be used in myopia research to study central and peripheral ocular optics during near work and to investigate the effects of optical myopia control interventions. Proof of concept measurements, performed on an artificial eye model and on 3 volunteers, showed good repeatability with foveal-peripheral data synchronization of 65 msec or better. The deviations from subjective cycloplegic refractions were not more than 0.31 D. Furthermore, we tested the dual-angle wavefront sensor in two novel measurement schemes: (1) focusing on a close target, and (2) accommodation step change.

Association of Myopia with cognitive function among one million adolescents

BACKGROUND

Myopia is a leading cause of visual impairment worldwide, and its increasing incidence is of public health concern. Cognitive function was associated with myopia among children, but evidence for adolescents is scarce. The purpose of this study was to determine whether myopia is associated with cognitive function, and which cognitive ability, verbal or non-verbal, is involved.

METHODS

We conducted a population-based cross-sectional study of 1,022,425 Israeli candidates for military service aged 16.5-18 years. Participants underwent a comprehensive battery of tests assessing verbal and non-verbal intelligence, which yields a summarized cognitive function score (CFS). In addition, subjective visual acuity examination followed by objective non-cycloplegic refraction was carried out for each participant. Association between myopia and cognitive function was evaluated by multivariable logistic regression models adjusted for gender, age, country of origin, socioeconomic status, years of education, body mass index, height and year of examination.

RESULTS

Compared to the intermediate CFS of the entire cohort, participants who had the highest CFS had 1.85-fold (95% CI, 1.81 to 1.89; P < .001) higher odds of having myopia and 2.73-fold (95% CI, 2.58 to 2.88; P < .001) higher odds of high myopia, while participants with the lowest CFS had 0.59-fold (95% CI, 0.57 to 0.61, P < .001) lower odds of having myopia. The verbal components of the cognitive function assessment had stronger associations with myopia than the non-verbal components (P < .001, for all).

CONCLUSIONS

Cognitive function, especially verbal intelligence, is strongly and consistently associated with myopia among adolescents.

The Prevalence of Myopia and Factors Associated with It Among Secondary School Children in Rural Vietnam

Purpose

To assess the prevalence of myopia and associated factors among secondary school children in a rural area of Vietnam.

Methods

A school-based cross-sectional study of children in grades six to nine was conducted in four secondary schools in Hoang Mai town, Nghe An Province, Vietnam, during December 2018 and January 2019. The status of myopia was defined as a spherical equivalent objective refractive error of −0.50 D or worse in either eye. A case–control study was conducted to explore factors associated with myopia, where children with myopia were considered to be cases, and children without myopia were considered to be controls. Factors associated with myopia were analyzed using univariate and multivariate logistic regression.

Results

The prevalence of myopia among secondary school children was 14.2% (95% CI: 12.7–15.7%) and tended to increase with grade, from 10.5% in grade six to 17.7% in grade nine. Myopia prevalence in girls was significantly higher than in boys. Factors associated with myopia were a mother with a college/university education (OR = 2.5, 95% CI = 1.2–5.3), parents who wore spectacles (OR = 2.0, 95% CI = 1.1–3.8), distance from near work (OR = 5.2, 95% CI = 3.5–7.9), and taking breaks after 30 minutes of continued reading (OR = 1.6, 95% CI = 1.1–2.5). However, there were inverse associations with myopia for children belonging to the wealthiest households (OR = 0.2, 95% CI = 0.1–0.5) and time spent performing outdoor activities (OR = 0.6, 95% CI = 0.4–0.9).

Conclusion

Our study showed that the prevalence of myopia is considerable among secondary children in rural areas of Vietnam. The prevalence of myopia tended to increase among children in higher grade levels. Thus, appropriate interventions should be developed and conducted to deal with the issue of school-age myopia.