Prevention of myopia, China

Epidemiological characteristics of myopia among school-age children before, during, and after the COVID-19 pandemic: a cohort study in Shenzhen, China

Objectives

To evaluate the epidemiological characteristics of myopia among school-aged children before, during, and after the coronavirus disease (COVID-19) pandemic.

Methods

A total of 848,697 students aged 6-15 years from 786 primary and secondary schools in Shenzhen, China, were randomly selected as research subjects. We conducted annual myopia screenings from 2019 to 2022. 2019 was considered before the COVID-19 pandemic, 2020 as during the pandemic, and 2021 and 2022 as after the pandemic. Demographic characteristics, visual acuity, and spherical equivalent refraction (SE) were collected.

Results

During the 4-year follow-up period, the uncorrected visual acuity (UCVA) of the study subjects progressed following a trend of -0.18 ± 0.30D (-0.17 ± 0.29D for boys, -0.21 ± 0.32Dfor girls) (p < 0.001). Those students who were in grade 4 aged 9-10 years at the baseline examination showed the greatest decline in visual acuity (0.23). The SE of the study subjects progressed following a trend of -1.00 ± 1.27D (-0.96 ± 1.25D for boys, -1.05 ± 1.31D for girls) (p < 0.001). The students who were in grade 5 aged 10-11 years at the baseline examination showed the greatest decline in SE (1.15D ± 1.22, p < 0.001). The prevalence of myopia (UCVA<5.0 and SE < -0.50D of any eye) increased by 28.2% (27.0% for boys and 29.8% for girls). Those students who were in grade 2 aged 7-8 years at the baseline examination showed the greatest increase in myopia prevalence (37.6%, p < 0.001). During the COVID-19 pandemic, the subjects' visual acuity and SE measurements decreased by -0.05 ± 0.19 (p < 0.001) and - 0.36 ± 0.89D (p < 0.001) respectively, and the prevalence of myopia increased by 11.3% (10.6% for boys and 12.2% for girls) (p < 0.001). The 3-year cumulative incidence of myopia for non-myopic grade 1 aged 6-7 years students with baseline SE of ≥1.00D, ≥ 0.50D and < 1.00D, ≥0D and < 0.50D, and ≥ -0.50D and < 0D were 6.8, 24.8, 39.0, and 48.1%, respectively.

Conclusion

During the COVID-19 pandemic, the SE of school-aged children showed myopic drift and decreased visual acuity. Myopia progressed faster among girls than among boys in the same grades. The risk of myopia among school-aged children persisted even after the home quarantine of the COVID-19 pandemic was lifted.

The efficacy and safety of combination therapy of repeated low-level red light and defocus-incorporated multiple segments spectacle lenses for myopia control in children: the study protocol for a 12-month, randomized, parallel-controlled, and single-center clinical trial

BACKGROUND

Myopia is increasing in prevalence worldwide. Combination therapy showed a better effect on myopia control than monotherapy. Repeated low-level red light therapy (RLRL) therapy and defocus-incorporated multiple segment (DIMS) spectacle lenses have been reported to retard myopia progression significantly. However, whether these two therapies are better than one is still unknown. The present study aims to report the study protocol of a trial designed to evaluate the efficacy and safety of combination therapy of RLRL and DIMS versus DIMS alone for reducing the progression of myopia among Chinese school-aged children.

METHODS

This study is a 12-month, randomized, parallel-controlled, single-center clinical trial. We will recruit children aged 8-12 years with spherical equivalence (SE) between - 0.50 D and - 6.00 D under cycloplegia in both eyes. We will recruit 66 participants with an allocation ratio of 1:1 from our hospital. Participants in the intervention group will be treated with an RLRL therapy device twice a day from Monday to Friday at home, 3 min per session, with a minimum interval of 4 h, under the supervision of their parents/guardians. They will wear DIMS spectacles for myopia correction during the day. Participants in the control group will not receive the RLRL therapy and will only wear DIMS spectacles to correct myopia. Participants from both groups will attend the hospital every 6 months. The primary outcome is the change in axial length at 12 months. Secondary outcomes include changes in refraction under cycloplegia, optical coherence tomography (OCT), multifocal electroretinogram (mfERG), color vision, and participants' self-reporting of adverse events at 12 months.

DISCUSSION

This study will report the efficacy and safety outcome of the combination therapy of RLRL and DIMS versus DIMS for school-aged children with myopia in detail.

TRIAL REGISTRATION

ChiCTR2300075398. Registered 4 September 2023. https://www.chictr.org.cn/bin/project/edit?pid=200751 .

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

Background

There is increasing evidence on the link between environmental factors and myopia in children and adolescents, yet with inconsistent conclusions. We investigated the associations between socioeconomic inequalities and green space with myopia in school-aged students participating in the Tianjin Child and Adolescent Research of Eye (TCARE) study.

Methods

We obtained data from a population-based dynamic cohort study conducted in Tianjin, China, in 2021 and followed up in 2022. We included 1 245 271 participants from 16 districts with an average age of 11.6 years (standard deviation = 3.3) in our analysis. We synthesized their area-level SES through a prediction model that combined economic, educational, and health care variables and assessed the greenness levels surrounding the school using the Normalized Difference Vegetation Index (NDVI) based on data obtained through satellite remote sensing. We performed generalised linear mixed effects analyses for each myopia outcome separately, with adjustments for students' sex, years of education completed, and the school's geographical location.

Results

We observed that students living in low SES areas had the highest prevalence of myopia (60.7%) in the last screening in 2022, as well as a higher incidence of one-year myopia (26.4%) compared to those residing in middle SES areas (22.7%). With a 0.1 increase in the 250, 500, and 1000 m buffer NDVI, the prevalence of myopia dropped by 6.3% (odds ratio (OR) = 0.937; 95% confidence interval (CI) = 0.915, 0.960), 7.7% (OR = 0.923; 95% CI = 0.900, 0.946), and 8.7% (OR = 0.913; 95% CI = 0.889, 0.937), respectively. The interaction analysis showed that low SES and low greenness exacerbate the prevalence of myopia. Findings from longitudinal analyses consistently demonstrated a correlation between higher values of NDVI and a slower progression of myopia. These findings remained robust across sensitivity analyses, including for variables on parental myopia and students' behaviors.

Conclusions

Exposure to green spaces could play a crucial role in slowing the progression of myopia among school-aged students. Myopia control policies should prioritise young populations residing in low SES areas with limited access to green spaces, as they face the highest potential risks.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Combined Effect of Outdoor Time and Other Modifiable Factors on Myopia Incidence Among Children and Adolescents - 9 PLADs, China, 2020

What is already known about this topic?

Myopia has been identified as a significant emerging challenge and policy priority among children and adolescents in China by the Ministry of Education and seven other departments. Limited research has been conducted to investigate the collective impact of outdoor time and other modifiable factors on the incidence of myopia.

What is added by this report?

This study provides support for the protective effect of combining increased outdoor time with other prevention strategies in reducing the incidence of myopia. The results indicate the presence of a dose-response relationship.

What are the implications for public health practice?

To effectively prevent myopia, it is important to implement comprehensive interventions that encompass various aspects such as outdoor time, eye-use habits, eye-use environments, and lifestyle modifications.

Eye exercises for myopia prevention and control: a comprehensive systematic review and meta-analysis of controlled trials

OBJECTIVES

To evaluate the efficacy of eye exercises in preventing and controlling myopia.

METHODS

We searched studies on eye exercises from nine Chinese and English databases from their inception to December 15, 2022. Using random-effect models and sensitivity/subgroup analyses, we estimated the effects of eye exercises compared to control on changes in three measures: visual acuity, refractive error (both quantified using standardized mean differences, SMDs), and protective/mitigating effects (assessed through risk ratios, RRs).

RESULTS

Eleven studies were included in the meta-analysis, with 921 participants. Nine studies had some concerns of bias in at least two domains, and two studies had a high risk of bias in two domains. Seven studies used visual acuity to measure myopia; visual acuity declined after eye-exercise interventions (SMD = -0.67, 95% CI -1.28 to -0.07, Z = 2.17, P = 0.03) and the effect was not better than control (SMD = -0.50, 95% CI -1.16 to 0.16, Z = 1.49, P = 0.14). Two studies used refractive error to measure myopia; the effect of eye-exercise interventions did not differ from control (SMD = -1.74, 95% CI -6.27 to 2.79, Z = 0.75, P = 0.45). Seven studies reported on protective/mitigating effects; eye exercises exhibited a greater protective/mitigating effect than control (RR = 0.40, 95% CI 0.23-0.71, Z = 3.13, P < 0.01).

CONCLUSIONS

Overall, the results suggest that eye exercises have limited to no efficacy in preventing or controlling myopia progression. Until robust evidence supports their efficacy, available evidence suggests retiring the eye-exercise policy.

Initiation of China Alliance of Research in High Myopia (CHARM): protocol for an AI-based multimodal high myopia research biobank

INTRODUCTION

High myopia is a pressing public health concern due to its increasing prevalence, younger trend and the high risk of blindness, particularly in East Asian countries, including China. The China Alliance of Research in High Myopia (CHARM) is a newly established consortium that includes more than 100 hospitals and institutions participating across the nation, aiming to promote collaboration and data sharing in the field of high myopia screening, classification, diagnosis and therapeutic development.

METHODS AND ANALYSIS

The CHARM project is an ongoing study, and its initiation is distinguished by its unprecedented scale, encompassing plans to involve over 100 000 Chinese patients. This initiative stands out not only for its extensive scope but also for its innovative application of artificial intelligence (AI) to assist in diagnosis and treatment decisions. The CHARM project has been carried out using a 'three-step' strategy. The first step involves the collection of basic information, refraction, axial length and fundus photographs from participants with high myopia. In the second step, we will collect multimodal imaging data to expand the scope of clinical information, for example, optical coherence tomography and ultra-widefield fundus images. In the final step, genetic testing will be conducted by incorporating patient family histories and blood samples. The majority of data collected by CHARM is in the form of images that will be used to detect and predict the progression of high myopia through the identification and quantification of biomarkers such as fundus tessellation, optic nerve head and vascular parameters.

ETHICS AND DISSEMINATION

The study has received approval from the Ethics Committee of Beijing Tongren Hospital (TREC2022-KY045). The establishment of CHARM represents an opportunity to create a collaborative platform for myopia experts and facilitate the dissemination of research findings to the global community through peer-reviewed publications and conference presentations. These insights can inform clinical decision-making and contribute to the development of new treatment modalities that may benefit patients worldwide.

TRIAL REGISTRATION NUMBER

ChiCTR2300071219.

Myopia among children and adolescents: an epidemiological study in Fuzhou City

Objective

To provide a reference for the prevention and control of myopia by analyzing and discussing the findings of an epidemiological survey of the prevalence of myopia among children and adolescents in Fuzhou City from 2019 to 2021.

Methods

Participants for this cross-sectional study were drawn from Gulou District and Minqing County in Fuzhou City using cluster random sampling to account for differences in population density, economic development, and other environmental variables.

Results

Myopia was more prevalent in 2020 than in 2019, but by 2021 it had dropped to about the same level as in 2019. Myopia was more prevalent among girls than boys during the course of the study period, with a three-year prevalence of 44.72% for boys and 52.16% for girls. Mild myopia accounted for 24.14% of all cases, followed by moderate myopia at 19.62%, and severe myopia at 4.58%. Students in urban regions had a prevalence of myopia equivalent to that of students in the suburbs, and this prevalence rose with age.

Conclusion

Myopia was quite prevalent among children and adolescents in Fuzhou City, and was shown to be steadily rising as students progressed through the school system. This suggests that all levels of government, educational institutions, medical facilities, and concerned parents in Fujian Province should focus on the issue of myopia and collaborate to reduce the risk factors for the development of myopia in school-aged participants.

Prevalence of myopia among senior students in Fenghua, Eastern China, before and during the COVID-19 pandemic

Background

Myopia is a common cause of vision impairment worldwide. In China, the prevalence, the affected population, and the onset age of myopia are prominent issues. Prevention and intervention of myopia are great public health concerns.

Methods

This school-based retrospective study retrieved visual acuity and refractive data of senior students (grade 12th) from six high schools in Fenghua City, Zhejiang Province, eastern China, from 2016 and 2022. Noncycloplegic autorefraction was performed for refractive status. Students were divided into three subgroups by their school types. The overall myopia prevalence, as well as the prevalence of low myopia, moderate myopia, and high myopia, were calculated separately for each year. Statistical analyzes were performed using SPSS 25.0 and Graphpad Prism software.

Results

The mean myopia prevalence in Fenghua was 84.5% (95% CI: 84.0-85.0%), and a slightly downward trend was found in myopia prevalence after 2019, but the change was not statistically significant (p = 0.078). The overall prevalence of myopia was 79.6, 85.2, and 86.1% in vocational high schools, general high schools, and key high schools, respectively, with statistically significant differences (p < 0.001). The prevalence of myopia among senior students in the vocational high school was significantly lower than that in the other two high schools. There's no significant change in the overall prevalence of myopia (84.7% vs. 84.3%, p = 0.265) before and during the COVID-19 pandemic, and it remained statistically insignificant after stratifying by gender (male p = 0.207, female p = 0.918) or school types (vocational high school p = 0.112; general high school p = 0.299; key high school p = 0.393).

Conclusion

The prevalence of myopia among senior students in Fenghua is relatively high, and the COVID-19 pandemic has no significant impact on it. The prevalence of myopia among vocational high school students is lower than that of general high school and key high school. Attention should be paid to the effects of educational pressure on the prevalence of myopia among students.

Design, methodology, and baseline of eastern China student health and wellbeing cohort study

Purpose

To describe the study design, methodology, and cohort profile of the Eastern China Student Health and Wellbeing Cohort Study. The cohort baseline includes (1) targeted disease (myopia, obesity, elevated blood pressure, and mental health) and (2) exposures (individual behaviors, environment, metabolomics, and gene and epigenetics).

Participants

Annual physical examination, questionnaire-based survey, and bio-sampling have been carried out in the study population. In the first stage (2019-2021), a total of 6,506 students in primary schools are enrolled in the cohort study.

Findings to date

Of all the cohort participants, the ratio of male to female is 1.16 among a total of 6,506 student participants, of which 2,728 (41.9%) students are from developed regions and 3,778 (58.1%) students are from developing regions. The initial age of observation is 6-10 years, and they will be observed until they graduate from high school (>18 years of age). (1) Targeted diseases: The growth rates of myopia, obesity, and high blood pressure vary by regions, and for developed regions, the prevalence of myopia, obesity, and elevated blood pressure is 29.2%, 17.4%, and 12.6% in the first year, respectively. For developing regions, the prevalence of myopia, obesity, and elevated blood pressure is 22.3%, 20.7%, and 17.1% in the first year, respectively. The average score of CES-D is 12.9 ± 9.8 in developing regions/11.6 ± 9.0 in developed regions. (2) Exposures: ① The first aspect of individual behaviors: the questionnaire topics include diet, physical exercise, bullying, and family. ② The second aspect of environment and metabolomics: the average desk illumination is 430.78 (355.84-611.56) LX, and the average blackboard illumination is 365.33 (286.83-516.84) LX. Metabolomics like bisphenol A in the urine is 0.734 ng/ml. ③ The third aspect of gene and epigenetics: SNPs (rs524952, rs524952, rs2969180, rs2908972, rs10880855, rs1939008, rs9928731, rs72621438, rs9939609, rs8050136 and so on) are detected.

Future plans

Eastern China Student Health and Wellbeing Cohort Study is aiming to focus on the development of student-targeted diseases. For children with student common diseases, this study will focus on targeted disease-related indicators. For children without targeted disease, this study aims to explore the longitudinal relationship between exposure factors and outcomes, excluding baseline confounding factors. Exposure factors include three aspects: (1) individual behaviors, (2) environment and metabolomics, and (3) gene and epigenetics. The cohort study will continue until 2035.

The Causal Effect of Education on Myopia: Evidence That More Exposure to Schooling, Rather Than Increased Age, Causes the Onset of Myopia

Purpose

To distinguish the effects of age and grade on the development of myopia.

Methods

Grade 1 (n = 1465, mean age 6.71 ± 0.29 years; 53.5% male) and Grade 2 students (n = 1381, mean age 7.76 ± 0.30 years; 52.5% male) were examined in 2018, with a follow-up examination in 2019. Cycloplegic spherical equivalent (SE) in diopter (D) was measured. Regression discontinuity (RD) analysis was used to assess the causal effects on refraction at each visit.

Results

The sample in a grade was divided into three 4-month age blocks according to their birth month, the youngest, middle, and the oldest. At the 2018 visit, within each grade, there were no significant differences in SE among age blocks (all P > 0.05), despite an age range of 12 months. However, comparing the youngest block in Grade 2 to the oldest block in Grade 1, an average age difference of four months, a significant difference in SE was found (0.82 ± 0.69 D vs. 1.05 ± 0.55 D, t-test P < 0.01). Formal RD analysis found a significant casual effect of grade increase on myopic refraction shift (β = -0.32 D; 95% CI, -0.73 to -0.01; P = 0.042). Consistent results were found using the 2019 data.

Conclusions

Increased grade, rather than increasing age, is the major cause of myopic shifts in refraction. A causal link implies that interventions aimed at reducing the myopigenic exposures experienced during a school year have the potential to markedly reduce the myopic shifts in refraction associated with a grade of schooling.

Association of time outdoors and patterns of light exposure with myopia in children

BACKGROUND/AIMS

To evaluate the association of reported time outdoors and light exposure patterns with myopia among children aged 9 years from the Growing Up in Singapore Towards Healthy Outcomes birth cohort.

METHODS

We assessed reported time outdoors (min/day), light exposure patterns and outdoor activities of children aged 9 years (n=483) with a questionnaire, the FitSight watch and a 7-day activity diary. Light levels, the duration, timing and frequency of light exposure were assessed. Cycloplegic spherical equivalent (SE), myopia (SE≤-0.5 D) and axial length (AL) of paired eyes were analysed using generalised estimating equations.

RESULTS

In this study, 483 (966 eyes) multiethnic children (50.0% boys, 59.8% Chinese, 42.2% myopic) were included. Reported time outdoors (mean±SD) was 100±93 min/day, and average light levels were 458±228 lux. Of the total duration children spent at light levels of ≥1000 lux (37±19 min/day), 76% were spent below 5000 lux. Peak light exposure occurred at mid-day. Children had 1.7±1.0 light exposure episodes/day. Common outdoor activities were walks, neighbourhood play and swimming. Greater reported time outdoors was associated with lower odds of myopia (OR=0.82, 95% CI 0.70 to 0.95/hour increase daily; p=0.009). Light levels, timing and frequency of light exposures were not associated with myopia, SE or AL (p>0.05).

CONCLUSION

Reported time outdoors, light levels and number of light exposure episodes were low among Singaporean children aged 9 years. Reported time outdoors was protective against myopia but not light levels or specific light measures. A multipronged approach to increase time outdoors is recommended in the combat against the myopia epidemic.

The impact of the pandemic highlights the urgent need for myopia guidelines: The clinicians' role

Myopia is already one of the leading causes of permanent vision impairment, including blindness, and the COVID-19 pandemic has exacerbated the global myopia-related burden among children owing to home confinement, increased screen time (e-learning), and decreased outside activities. To reverse the rising trend of myopia and myopia-related blindness, collaborative efforts are required. There is a wealth of evidence-based medicine (EBM) data on the epidemiology of myopia and effective interventions, but very little has been published on the clinicians' roles and responsibilities. However, this aspect is critical because preventing the onset and progression of myopia necessitates extensive health promotion and advocacy efforts among decision-makers. Only broad medical expert collaboration can bring about the necessary changes in children's lifestyle and education. This article discusses clinicians' critical roles in preventing the onset and progression of myopia.

A Latent Class Analysis of Student Eye Care Behavior: Evidence From a Sample of 6–17 Years Old in China

Purpose

To understand the latent classes and distribution of an adolescent eye care behavior, and to provide a basis for the formulation of appropriate adolescent vision health management interventions.

Methods

Information on eye behavior and eye health of primary and secondary school students in Wuhan was collected by multistage stratified cluster sampling. The latent class analysis (LCA) method was used to analyze the students' eye care behavior, and the latent class model (LCM) was built.

Results

A total of 6,130 students were enrolled in this study, of which 53.56% were males, aged from 6 to 17 years old, with an average age of 10.33 ± 2.60. The latent class results classified the adolescents' eye care behaviors into bad behaviors, moderate behaviors, and healthy behaviors. The model fitting results were as follows: Akaike Information Criterion (AIC) was 36,698.216, Bayesian Information Criterion (BIC) was 36,906.565, Adjusted Bayesian Information Criterion (aBIC) was 36,808.056, and entropy was 0.838.Compared with the healthy behaviors class, the bad behaviors class was more prevalent in high schools (p = 0.003), non-demonstration schools (p = 0.001), and most of this group had astigmatism (p = 0.002). The moderate behaviors class predominately consisted of females (p = 0.001), 15–17 years old (p = 0.005, 6~8 years old as the reference), from non-demonstration schools (p < 0.001), and most had myopia (p = 0.009).

Conclusion

There were differences in basic demographic characteristics, visual acuity development level, and family visual environment among different classes. In the management and intervention of an adolescent vision health, we should continue to promote the visual health management of adolescents based on visual monitoring and realize the early intervention and guidance of individuals in bad behaviors class.

Novel Uses and Challenges of Artificial Intelligence in Diagnosing and Managing Eyes with High Myopia and Pathologic Myopia

Myopia is a global health issue, and the prevalence of high myopia has increased significantly in the past five to six decades. The high incidence of myopia and its vision-threatening course emphasize the need for automated methods to screen for high myopia and its serious form, named pathologic myopia (PM). Artificial intelligence (AI)-based applications have been extensively applied in medicine, and these applications have focused on analyzing ophthalmic images to diagnose the disease and to determine prognosis from these images. However, unlike diseases that mainly show pathologic changes in the fundus, high myopia and PM generate even more data because both the ophthalmic information and morphological changes in the retina and choroid need to be analyzed. In this review, we present how AI techniques have been used to diagnose and manage high myopia, PM, and other ocular diseases and discuss the current capacity of AI in assisting in preventing high myopia.

Myopia: An Increasing Problem for Medical Students at the University of Gondar

Purpose

The purpose of this study was to assess the prevalence and associated factors of myopia among medical students at the University of Gondar College of Medicine and Health Sciences, Northwest Ethiopia.

Patients and Methods

Institution-based cross-sectional study was conducted at the University of Gondar College of Medicine and Health Sciences from June 20 to August 15, 2021. A simple random sampling technique with proportional allocation was used to select 492 students. Interviewer-administered questionnaire, Snellen acuity chart, pinhole, retinoscope and direct ophthalmoscope were used to collect the data. The data were entered to EpiData version 4.6 and exported to SPSS version 25 for analysis. Descriptive statistics were summarized by measures of central tendency. Variables with p-value ≤0.2 in bivariable regression were entered into a multivariable logistic regression model. Adjusted odds ratio with 95% confidence interval was used and variables with p-values <0.05 were considered as statistically significant.

Results

A total of 492 respondents participated giving a response rate of 98.3%. The prevalence of myopia was found to be 16.7% (95% CI = 12.8–19.4%). Urban residents (AOR = 1.56; 95% CI: 1.28–6.21), family history of myopia (AOR = 2.31; 95% CI: 1.33–4.54), near-work activity of 5–7 hours (AOR = 2.41; 95% CI: 1.31–5.76) and ≥8 hours (AOR = 4.35; 95% CI: 1.96–9.66), outdoor activity for <3 hours (AOR = 1.65 95% CI: (1.14–4.53), were significantly associated with myopia.

Conclusion

The prevalence of myopia among medical students at the University of Gondar College of Medicine and Health Sciences was high. Urban residency, positive family history, longer time spent on near-work activities and less outdoor activity were positively associated with myopia.

Association of School Education With Eyesight Among Children and Adolescents

IMPORTANCE

Myopia in youths is an increasingly common global problem, associated with significant social and economic burden worldwide.

OBJECTIVES

To explore the association of school education with myopia and investigate its scale, controlling confounding factors, such as age and socioeconomic status.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from July 2019 to December 2020 using regression discontinuity (RD) based on the Compulsory Education Law to examine the complex association of school education with myopia. Participants were youths from grades 1 to 12 before tertiary or university studies in China, including individuals from 815 primary schools, 373 junior high schools, and 145 senior high schools. Data were analyzed from February through June 2021.

EXPOSURES

Participants born earlier in a year (ie, January to August) were assigned 1 more year of education and were considered to be in the treated group, while participants born September to December were considered to be in the control group.

MAIN OUTCOMES AND MEASURES

Differences in mean spherical equivalent refractive error (MSE) and uncorrected visual acuity (UVA) between treated and control groups were calculated.

RESULTS

Among a mean (SD) of 812 979 (55 953) participants across 5 surveys survey (mean SD 44.9% [0.5%] female participants; mean [SD] age, 11.19 [2.60] years), the mean (SD) MSE was -1.30 (2.93) diopters and mean (SD) UVA was 4.77 (0.34) points. Every additional year at school was associated with an decrease in MSE of -0.17 diopters/y (95% CI, -0.22 to -0.11 diopters/y) and a decrease in UVA of -0.03 points/y (95% CI, -0.04 to -0.02 points/y), which accounts for nearly 66.4% (95% CI, 85.9% to 43.0%) and 78.9% (95% CI, 102.6% to 55.3%) of changes of MSE and UVA, respectively, among all factors for youths. The greatest MSE shifts occurred in grades 3 and 7 (eg, for the June 2019 census, the RD was -0.26 diopters/y [95% CI, -0.33 to -0.20 diopters/y] for grade 3 and -0.41 diopters/y [95% CI, -0.66 to -0.15 diopters/y] for grade 7).

CONCLUSIONS AND RELEVANCE

These findings suggest that receiving more years of education, instead of age, may be a risk factor associated with myopia progression in youths.

Orthokeratology Lens Wear for 2 Years in Children Did Not Alter Tear Film Lipid Thickness by Non-Invasive Interferometry

Purpose

Previous studies suggest that overnight orthokeratology (OOK) may be detrimental to tear function. We aimed to investigate the effect of OOK on lipid layer thickness (LLT), blink pattern, and meibomian gland and elucidate the relationship of these variables.

Methods

Thirty-seven participants who wore OOK lenses every night for at least 2 years and twenty-four healthy non-contact lens wearers (controls) were enrolled in this retrospective study. LipiView interferometry, blink pattern analysis, the ocular surface status, and morphology and function of the meibomian gland were determined.

Results

The OOK group and healthy controls had similar LLT, blink patterns, ocular surface status, and the function of the meibomian gland. OOK participants demonstrated higher meiboscore in the lower eyelids (p < 0.05) but not in the upper eyelids. Within the OOK group, LLT was significantly impacted by the partial blink rate (p < 0.05) and the total score of the upper meibomian gland (p = 0.10).

Conclusions

Wearing OOK for 2 or more years increased lower eyelid meibomian gland dropout but did not have a reduction of LLT.

Relationship Between Myopia and Other Risk Factors With Anxiety and Depression Among Chinese University Freshmen During the COVID-19 Pandemic

Purpose: To investigate the association of myopia and other risk factors with anxiety and depression among Chinese university freshmen during the coronavirus disease 2019 (COVID-19) pandemic.

Methods: This cross-sectional study was conducted at the Tianjin Medical University from October 2020 to December 2020. Ophthalmic examination of the eyes was performed by an experienced ophthalmologist. Detailed information on depression, anxiety, and other risk factors was collected via the Self-rating Anxiety Scale and Self-rating Depression Scale.

Results: The overall prevalence of anxiety and depression in our study was 10.34 and 25.13%, respectively. The prevalence of myopia and high myopia as 92.02 and 26.7%, respectively. There were significant associations between anxiety and spectacle power [odds ratios (OR) = 0.89; 95% CI: 0.81–0.98, P = 0.019], sphere equivalent (OR = 0.89; 95% CI: 0.81– 0.98, P = 0.025), sleep time (OR = 0.53; 95% CI: 0.35–0.79, P = 0.002), and body mass index (OR = 0.93; 95% CI: 0.86–0.99, P = 0.047). In the multivariable linear regression models, spectacle power (β = −0.43; 95% CI: −0.68 to −0.19, P = 0.001) and sphere equivalent (β = −0.36; 95% CI: −0.60 to −0.11, P = 0.005) were negatively associated with anxiety scores, whereas axial length (β = 0.54; 95% CI: 0.02–1.07, P = 0.044) was positively correlated with anxiety scores. Every 1 h decrease in sleep time was associated with a 0.12-point increase in depression score.

Conclusion: Myopia was associated with anxiety and anxiety scores. The greater the degree of myopia, the higher the anxiety score. However, myopia was not found to be associated with depression. The results highlight the importance of providing psychological support to students with myopia during the COVID-19 pandemic.

Pandemic of Childhood Myopia. Could New Indoor LED Lighting Be Part of the Solution?

The existence of a growing myopia pandemic is an unquestionable fact for health authorities around the world. Different possible causes have been put forward over the years, such as a possible genetic origin, the current excess of children’s close-up work compared to previous stages in history, insufficient natural light, or a multifactorial cause. Scientists are looking for different possible solutions to alleviate it, such as a reduction of time or a greater distance for children’s work, the use of drugs, optometric correction methods, surgical procedures, and spending more time outdoors. There is a growing number of articles suggesting insufficient natural light as a possible cause of the increasing levels of childhood myopia around the globe. Technological progress in the world of lighting is making it possible to have more monochromatic LED emission peaks, and because of this, it is possible to create spectral distributions of visible light that increasingly resemble natural light in the visible range. The possibility of creating indoor luminaires that emit throughout the visible spectrum from purple to infrared can now be a reality that could offer a new avenue of research to fight this pandemic.

Imaging Features by Machine Learning for Quantification of Optic Disc Changes and Impact on Choroidal Thickness in Young Myopic Patients

Purpose: To construct quantifiable models of imaging features by machine learning describing early changes of optic disc and peripapillary region, and to explore their performance as early indicators for choroidal thickness (ChT) in young myopic patients.

Methods: Eight hundred and ninety six subjects were enrolled. Imaging features were extracted from fundus photographs. Macular ChT (mChT) and peripapillary ChT (pChT) were measured on swept-source optical coherence tomography scans. All participants were divided randomly into training (70%) and test (30%) sets. Imaging features correlated with ChT were selected by LASSO regression and combined into new indicators of optic disc (IODs) for mChT (IOD_mChT) and for pChT (IOD_pChT) by multivariate regression models in the training set. The performance of IODs was evaluated in the test set.

Results: A significant correlation between IOD_mChT and mChT (r = 0.650, R² = 0.423, P < 0.001) was found in the test set. IOD_mChT was negatively associated with axial length (AL) (r = −0.562, P < 0.001) and peripapillary atrophy (PPA) area (r = −0.738, P < 0.001) and positively associated with ovality index (r = 0.503, P < 0.001) and torsion angle (r = 0.242, P < 0.001) in the test set. Every 1 × 10 μm decrease in IOD_mChT was associated with an 8.87 μm decrease in mChT. A significant correlation between IOD_pChT and pChT (r = 0.576, R² = 0.331, P < 0.001) was found in the test set. IOD_pChT was negatively associated with AL (r = −0.478, P < 0.001) and PPA area (r = −0.651, P < 0.001) and positively associated with ovality index (r = 0.285, P < 0.001) and torsion angle (r = 0.180, P < 0.001) in the test set. Every 1 × 10 μm decrease in IOD_pChT was associated with a 9.64 μm decrease in pChT.

Conclusions: The study introduced a machine learning approach to acquire imaging information of early changes of optic disc and peripapillary region and constructed quantitative models significantly correlated with choroidal thickness. The objective models from fundus photographs represented a new approach that offset limitations of human annotation and could be applied in other areas of fundus diseases.

IMI Risk Factors for Myopia

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

Association of Myopia in Elementary School Students in Jiaojiang District, Taizhou City, China

Background

The aim of our study was to evaluate the prevalence of myopia in elementary school students and to assess the risk factors for myopia.

Methods

This school-based cross-sectional study was performed on students from two elementary schools in Jiaojiang, Taizhou City, China. A total of 556 students, whose age ranged from 9 to 12 years, were included. The uncorrected visual acuity and noncycloplegic refractive error tests were performed to determine the myopia. Each student was asked to fulfill the questionnaire about the possible factors associated with myopia. Multivariate logistic analyses of risk factors were conducted.

Results

The overall prevalence of myopia among those students was 63.7%, ranged from 53.4% in grade 4 to 72.5% in grade 6. Multivariate logistic analysis showed that adjusting the height of desks and chairs according to the changing height and the presence of myopia in parents were significantly associated with myopia in these students, respectively.

Conclusions

Our results showed that myopia among elementary school students was associated with environmental and hereditary factors.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Age-Related Change of Axial Length, Spherical Equivalent, and Prevalence of Myopia and High Myopia in School-Age Children in Shanghai: 2014–2018

Purpose. To investigate the age-related change of axial length (AL), spherical equivalent (SE), and prevalence of myopia and high myopia in children at 7–18-year-olds in Shanghai in 2014 and 2018, respectively. Methods. This was an observational study in Shanghai. The same 3 schools were selected in 2014 and 2018, respectively. AL, SE, prevalence of myopia and high myopia, height, and weight were measured. A questionnaire regarding the lifestyles was completed. Results. Mean age was smaller in 2018 than in 2014 ( $P<0.001$ ), and mean AL was shorter in 2018 than in 2014 ( $P=0.003$ ), whereas mean SE was greater in 2018 than in 2014 ( $P<0.001$ ). The prevalence of myopia and high myopia was lower in 2018 than in 2014 ( $P<0.001$ and $P=0.013$ , respectively). Mean AL increased with age from 7-year-olds to 18-year-olds in 2014 and 2018 (both $P<0.001$ ), respectively. Mean SE decreased with age in 2014 and 2018 (both $P<0.001$ ), respectively. The prevalence of myopia and high myopia increased with age in 2014 and 2018 (all $P<0.001$ ), respectively. Less mean time outdoors and more mean time of study of all children were observed in 2018 than in 2014 ( $P=0.018$ and $P<0.001$ , respectively). Conclusion. This study shows normative growth values for AL and SE in Shanghai children at the age of 7–18-year-olds, as well as the age-specific prevalence of myopia and high myopia.