Ethnic disparity in prevalence and associated risk factors of myopia in adolescents

The association between screen time exposure and myopia in children and adolescents: a meta-analysis

OBJECTIVE

This study aimed to systematically review epidemiological evidence on associations between screen time exposure and myopia in children and adolescents, and to quantitatively evaluate summary effect estimates from existing literature.

METHOD

There were three online databases including PubMed, Embase, and Web of Science, for epidemiological studies on screen time exposure and myopia published before June 1, 2023. The risk of bias was assessed by the Newcastle Ottawa Scale (NOS) checklist. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the correlation between screen time exposure and myopia using random or fixed-effect models by exposure type (categorical/continuous). We also performed subgroup analysis by screen device type, study quality, geographic region, and research period.

RESULTS

We searched 7,571 records from three databases and identified 19 eligible studies, including 14 high-quality studies and 5 moderate-quality studies. Meta-analyses suggested that there was a statistically significant correlation between screen time (high vs. low) and myopia. The pooled ORs with 95%CIs were respectively 2.24 (1.47-3.42) for cross-sectional studies, and 2.39 (2.07-2.76) for cohort studies. We also found a significant association between continuous exposure to screen time (per 1 h/d increase) and myopia in cohort studies. The pooled ORs with 95%CIs were 1.07 (1.01-1.13). In subgroup analysis stratified by screen device type in cross-sectional studies, screen time exposures from computers (categorical: OR = 8.19, 95%CI: 4.78-14.04; continuous: OR = 1.22, 95%CI: 1.10-1.35) and televisions (categorical: OR = 1.46, 95%CI: 1.02-2.10) were associated with myopia, while smartphones were not. Although publication bias was detected, the pooled results did not show significant changes after adjustment using the trim and fill method.

CONCLUSION

Our findings support that screen time exposure was significantly associated with myopia in children and adolescents. Notably, screen time exposure from computers may have the most significant impact on myopia.

Association Between Physical Indicators and Myopia in American Adolescents: National Health and Nutrition Examination Survey 1999-2008

PURPOSE

Myopia is the most prevalent refractive error, imposing a substantial economic burden. Physical indicators constitute significant influencing factors for myopia. The National Health and Nutrition Examination Survey (NHANES) investigates the health and nutritional status of both children and adults in the United States. This study leveraged NHANES to explore the association between physical indicators and myopia among American adolescents.

DESIGN

Retrospective case-control study.

METHODS

The final study cohort consisted of 9008 adolescents. Demographic data, physical indicators, and vision data were extracted. The association between myopia and demographic factors, as well as physical indicators, employed weighted methods. Regression models were utilized to identify the associations between physical indicators and myopia. Cumulative odds logistic regression analysis was employed to investigate the association between physical indicators and the degree of myopia. Restricted cubic spline analysis was employed to examine the potential nonlinear relationship between physical indicators and the risk of myopia.

RESULTS

The occurrence of myopia was significantly correlated with age (P < .001) and race (P = .019). Adolescents in the fourth percentile for weight (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.13-1.70) and body mass index (BMI) (OR 1.26, 95% CI 1.05-1.51) exhibited an increased possibility of myopia. The highest risk of myopia was observed when the BMI approached 30. Height emerged as a risk factor for the degree of myopia (OR 1.02, 95% CI 1.01-1.03).

CONCLUSIONS

A certain association existed between physical indicators and myopia. Weight and BMI were related to the occurrence of myopia, while height and race were associated with the degree of myopia.

Secondhand smoke exposure and ocular health: A systematic review

The toxicology of secondhand smoke (SHS), along with the harm of its exposure to human health, has been generally acknowledged; however, specific evidence is lacking on the association between SHS exposure and ocular health. In this systematic review (PROSPERO registration number: CRD42022247992), we included 55 original articles published by 12 May 2023, which dealt with SHS exposure and ocular disorders, such as eye irritation, conjunctivitis, dry eye diseases, uveitis, myopia, astigmatism, contact lens discomfort, age-related macular degeneration, glaucoma, and thyroid eye disease that addressed the ocular neurovascular structures of the macular, retinal nerve fiber layer, choroid, and corneal biomechanical parameters. We found compelling correlational evidence for eye irritation, conjunctivitis, and dry eye symptoms-supporting that SHS exposure was positively associated with inflammatory and allergic changes in the eyes. Yet, evidence about the associations between SHS exposure and other ocular disorders, structures, and parameters is still limited or controversial. Given the limitations of existing literature, more investigations with high quality and rigorous design are warranted to elucidate the potentially harmful effects of SHS exposure on ocular health.

Prevalence of Myopia and Its Related Factors Among University Students in Madinah, Saudi Arabia

BACKGROUND

Myopia, a common refractive error, is a growing global health burden influenced by both genetic and environmental factors. Despite its high prevalence, studies on its prevalence and risk factors among university students are lacking.

OBJECTIVES

The objective of this study is to investigate the prevalence of myopia and its associated factors among college students in Saudi Arabia's Madinah region.

METHODS

A cross-sectional study was conducted in Al-Madinah, Saudi Arabia, from February to June 2023, utilizing a survey that was distributed to college students through a social media application.

RESULTS

A total of 433 university students from Al-Madinah province were enrolled in this study; 66.3% were females and 33.7% were males. Participants' ages ranged from 18 to 33 years with a mean of 21.3 ± 2.0 years. The prevalence of myopia among college students in Al-Madinah and its provinces was 57.3%, and 87.9% of them had myopia in both eyes. Respondents with an electronic screen time of more than three hours and a reading distance of less than 15cm were at significant risk of myopia with p-values of 0.037 and 0.019, respectively.

CONCLUSIONS

A significant prevalence of myopia has been observed among university students in Madinah. Studying in scientific and medical fields, having eye diseases, prolonged use of digital devices, limiting daily outdoor activities to one hour, and having a reading distance of less than 15 cm significantly increased the risk of myopia. Encouraging education and screening programs for myopia prevention and control is crucial.

Prevalence of Dome-Shaped Macula and Tilted Disc Syndrome in High Myopia

BACKGROUND AND OBJECTIVE

Dome-shaped macula (DSM) and tilted disc syndrome (TDS) are two macular abnormalities that may occur in eyes with high myopia. The aim of this study was to determine the prevalence of both entities in our population.

PATIENTS AND METHODS

This was a prospective and observational study. Optical coherence tomography of the macula was performed in eyes with high myopia (spherical equivalent [SE] of -8D or greater) to assess the prevalence of DSM and TDS.

RESULTS

Sixty-eight eyes were included. Three eyes (4.41%) had DSM and 8 (11.76%) eyes had TDS. The most common macular anomaly was posterior staphyloma (PS) (12 [17.65%]). From the eyes with DSM (n = 3), only two presented PS. An older age and a higher SE were predisposing factors for PS (P = 0.003).

CONCLUSIONS

A lower prevalence of DSM and a higher prevalence of TDS was observed in our population compared to those reported in literature. [Ophthalmic Surg Lasers Imaging Retina 2023;54:568-572.].

Association between vitamin D and myopia in adolescents and young adults: Evidence of national cross-sectional study

PURPOSE

Studies have indicated that the observed association between vitamin D and myopia was confounded by time spent outdoors. This study aimed to elucidate this association using a national cross-sectional dataset.

METHODS

Participants with 12 to 25 years who participated in non-cycloplegic vision exam from National Health and Nutrition Examination Survey (NHANES) 2001 to 2008 were included in the present study. Myopia was defined as spherical equivalent of any eyes ≤ -0.5 diopters (D).

RESULTS

7,657 participants were included. The weighted proportion of emmetropes, mild myopia, moderate myopia, and high myopia were 45.5%, 39.1%, 11.6%, and 3.8%, respectively. After adjusting for age, gender, ethnicity, TV/computer usage, and stratified by education attainment, every 10 nmol/L increment of serum 25(OH)D concentration was associated with a reduced risk of myopia (odds ratio [OR] = 0.96, 95% confidence interval [95%CI] 0.93-0.99 for any myopia; OR = 0.96, 95%CI 0.93-1.00 for mild myopia; OR = 0.99, 95%CI 0.97-1.01 for moderate myopia; OR = 0.89, 95%CI 0.84-0.95 for high myopia). Serum 25(OH)D level was closely correlated with time spent outdoors. After categorizing time spent outdoors into quarters (low, low-medium, medium-high, and high), every 1 quarter increment of time spent outdoors was associated with 2.49 nmol/L higher serum 25(OH)D concentration. After adjusting for time spent outdoors, serum 25(OH)D level did not show significant association with myopia (OR = 1.01, 95%CI 0.94-1.06 for 10 nmol/L increment).

CONCLUSIONS

The association between high serum vitamin D and reduced risk of myopia is confounded by longer time spent outdoors. Evidence from the present study does not support that there is a direct association between serum vitamin D level with myopia.

Association Between Myopia and Primary Open-Angle Glaucoma by Race and Ethnicity in Older Adults in the California Medicare Population

Importance

Racial and ethnic differences in the association between myopia and primary open-angle glaucoma (POAG) are not well understood.

Objective

To investigate the association between myopia and POAG in the 2019 California Medicare population and to investigate whether there was evidence of effect measure modification of this association by race and ethnicity.

Design, Setting, and Participants

This cross-sectional study used administrative claims data from 2019 California Medicare beneficiaries 65 years or older with California residence and active coverage with Medicare parts A and B. Analysis took place between October 2021 and October 2023.

Exposures

The primary exposure was myopia, which was defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis codes.

Main Outcomes and Measures

The outcome of interest was POAG, which was defined by ICD-10-CM code.

Results

Of 2 717 346 California Medicare beneficiaries in 2019, 1 440 769 (53.0%) were aged 65 to 74 years, 1 544 479 (56.8%) identified as female, 60 211 (2.2%) had myopia, and 171 988 (6.3%) had POAG. Overall, 346 723 individuals (12.8%) identified as Asian, 117 856 (4.3%) as Black, 430 597 (15.8%) as Hispanic, 1 705 807 (62.8%) as White, and 115 363 (4.2%) as other race and ethnicity. In adjusted logistic regression analyses, beneficiaries with myopia had higher odds of POAG compared with beneficiaries without myopia (odds ratio [OR], 2.41; 95% CI, 2.35-2.47). In multivariable models stratified by race and ethnicity, the association between myopia and POAG was stronger in Asian (OR, 2.74; 95% CI, 2.57-2.92), Black (OR, 2.60; 95% CI, 2.31-2.94), and Hispanic (OR, 3.28; 95% CI, 3.08-3.48) beneficiaries compared with non-Hispanic White beneficiaries (OR, 2.14; 95% CI, 2.08-2.21).

Conclusions and Relevance

In the 2019 California Medicare population, myopia was associated with greater adjusted odds of POAG. This association was stronger among Asian, Black, and Hispanic beneficiaries compared with non-Hispanic White beneficiaries. These findings suggest possible disparities in glaucoma risk by race and ethnicity in individuals with myopia and may indicate greater need for glaucoma screening in individuals with myopia from racial and ethnic minority backgrounds.

Myopia progression risk assessment score (MPRAS): a promising new tool for risk stratification

Timely identification of individuals "at-risk" for myopia progression is the leading requisite for myopia practice as it aids in the decision of appropriate management. This study aimed to develop 'myopia progression risk assessment score' (MPRAS) based on multiple risk factors (10) to determine whether a myope is "at-risk" or "low-risk" for myopia progression. Two risk-score models (model-1: non-weightage, model-2: weightage) were developed. Ability of MPRAS to diagnose individual "at-risk" for myopia progression was compared against decision of five clinicians in 149 myopes, aged 6-29 years. Using model-1 (no-weightage), further 7 sub-models were created with varying number of risk factors in decreasing step-wise manner (1a: 10 factors to 1g: 4 factors). In random eye analysis for model-1, the highest Youden's J-index (0.63-0.65) led to the MPRAS cut-off score of 41.50-43.50 for 5 clinicians with a sensitivity ranging from 78 to 85% and specificity ranging from 79 to 87%. For this cut-off score, the mean area under the curve (AUC) between clinicians and the MPRAS model ranged from 0.89 to 0.90. Model-2 (weighted for few risk-factors) provided similar sensitivity, specificity, and AUC. Sub-model analysis revealed greater AUC with high sensitivity (89%) and specificity (94%) in model-1g that has 4 risk factors compared to other sub-models (1a-1f). All the MPRAS models showed good agreement with the clinician's decision in identifying individuals "at-risk" for myopia progression.

Extreme myopia is more susceptible to SOX2 gene than high myopia

PURPOSE

To explore the association between two single-nucleotide polymorphisms (SNPs) in the SOX2 gene and high and extreme myopia in the Han Chinese population.

MATERIALS AND METHODS

A genetic association study using a case-control method was performed with 139 high myopia, 318 extreme myopia, and 918 healthy participants from the Chinese Han population. Two SNPs (rs4459940 and rs4575941) near SOX2 gene were selected for genotyping. We compared the allelic frequencies and haplotypes of the SNPs to assess their association with high and extreme myopia. This study was adjusted for sex and age of participants in the groups.

RESULT

The mean ages of the extreme myopia and control subjects were 47.44 ± 15.59 and 44.15 ± 14.08 years, respectively. The rs4575941 SNP of the SOX2 gene and the GG and AG genotypes showed no significant association with the risk of high myopia as opposed to the AA genotype (GG, OR = 0.94, 95% CI = 0.55-1.60, P = 0.820, Pc = NS; AG, OR = 0.91, 95% CI = 0.54-1.52, P = 0.708, Pc = NS). However, the frequency of the risk G allele of rs4575941 was significantly higher in the extreme myopia group than in the control group (OR = 1.31, 95% CI = 1.08-1.59; P = 0.007; Pc = 0.014). Furthermore, there were significant differences in the GG genotype frequency between the extreme myopia and control groups (OR = 1.77, 95% CI = 1.45-2.74, P = 0.009, Pc = 0.036). The A-G haplotype frequency was higher in the extreme group (OR = 1.27, 95% CI = 1.05-1.55, P = 0.014), while there were no significant differences found in high myopia group (OR = 1.18, 95% CI = 0.77-1.31, P = 0.979).

CONCLUSION

The SOX2 rs4575941 polymorphism, in Chinese Han population, contributes to the susceptibility of extreme myopia. SOX2 may thus be implicated in extreme myopia rather than in high myopia.

Myopia and Near Work: A Systematic Review and Meta-Analysis

BACKGROUND

Myopia is a global public health problem affecting quality of life and work productivity. Data is scarce regarding the effects of near work on myopia. Providing a larger meta-analysis with life-long perspective, including adults and occupational exposure seemed needed.

METHODS

We searched PubMed, Cochrane Library, Embase and Science Direct for studies reporting myopia prevalence in near work. Myopia was defined as a mean spherical equivalent ≤ -0.50 diopter. We performed a meta-analysis using random-effects model on myopia prevalence, myopia progression per year, and odds ratio (OR) of myopia in near work, completed by subgroup analyses and meta-regressions on patients' characteristics, type of work in adults, geographic zones, time and characteristics of near work.

RESULTS

We included 78 studies, representing a total of 254,037 participants, aged from 6 to 39 years. The global prevalence of myopia in near work was 35% (95% CI: 30 to 41%), with a prevalence of 31% (95% CI: 26 to 37%) in children and 46% (95% CI: 30 to 62%) in adults. Myopia progression was -0.39 diopters per year (-0.53 to -0.24 D/year), ranging from -0.44 (-0.57 to -0.31) in children to -0.25 D/year (-0.56 to 0.06) in adults. The odds of myopia in workers exposed vs. non-exposed to near work were increased by 26% (18 to 34%), by 31% (21 to 42%) in children and 21% (6 to 35%) in adults. Prevalence of myopia was higher in adults compared to children (Coefficient 0.15, 95% CI: 0.03 to 0.27).

CONCLUSIONS

Near work conditions, including occupational exposure in adults, could be associated with myopia. Targeted prevention should be implemented in the workplace.

Ethnic Disparities in Risk Factors for Myopia among Han and Minority Schoolchildren in Shawan, Xinjiang, China

SIGNIFICANCE

The ethnic differences in myopia rates, ocular dimensions, and risk factors between Han and non-Han schoolchildren observed in this study may help fill the knowledge gap about ethnic minorities and are important for China and other countries to address vision-related health inequalities among different ethnic groups.

PURPOSE

This study aimed to investigate the risk factors of juvenile myopia and elucidate the disparities of risk factors among Han and non-Han school students in Xinjiang, China.

METHODS

A population-based cross-sectional study of 876 schoolchildren from grades 1 to 9 was conducted in the Anjihai Middle School in Shawan, Xinjiang Uygur Autonomous Region, China. Visual acuity and ocular biometry were assessed, and personal information, including behavior, birth status, and familial factors, was collected using self-made standardized questionnaires.

RESULTS

The myopia rate among students of Han ethnicity (50.5%) was the highest, followed by Hui (41.3%) and Uygur et al. (32.0%, P < .001). Similar patterns were observed for mean axial length. The mean axial lengths are 23.7, 23.4, and 23.3 mm, respectively ( P = .01). Overall, performing high-quality eye exercises, longer sleep duration, being born in summer, parental smoking, and consuming more food containing anthocyanins were all associated with a lower incidence of myopia. Meanwhile, Han ethnicity, intensive near task, bad eye habits, and myopic mothers were associated with higher odds of myopia. After adjusting for environmental influences pertaining to myopia, the variation in myopia prevalence between Han and Uygur et al. remained significant, whereas it changed to not significant between Han and Hui ethnicities.

CONCLUSIONS

Significant disparities were found in the prevalence of myopia among various ethnic groups in Shawan, Xinjiang. Life habits, birth status, and familial factors may contribute to such variance and play different roles in the occurrence of juvenile myopia among various ethnicities.

Increasing prevalence of myopia and the impact of education in primary-school students in Xi'an, north-western of China

Purpose

The present study was performed to detect the prevalence of myopia among primary-school students in Xi'an, north-western of China.

Methods

The present study was a school-based study with students aged from 6 to 13 years old. All the individuals underwent ophthalmological examination and spherical equivalent (SE) of refractive error were measured with non-cycloplegic refraction. Myopia was defined as a SE of ≤ -0.5 diopters (D), and further divided into three stratified groups based on SE: low myopia (≤ -0.5 to >-3.0 D), moderate myopia (≤ -3.0 to >-6.0 D), and high myopia (≤ -6.0 D). Relative risk factors, including age, sex, grade and ethnicity were investigated using questionnaire.

Results

A total of 4,680 individuals were eligible for this survey and 4,654 (99.4% participation rate) were finally included (51.2% boys). The mean age of participants was 8.756 ± 1.727 years. The whole city-level prevalence of total myopia was 57.1% (95% CI: 55.7-58.6%). Additionally, the prevalence of low, moderate, and high myopia was 45.0% (95% CI: 43.5-46.4%), 11.1% (95% CI: 10.2-12.0%), and 1.0% (95% CI: 0.7-1.3%), respectively. Moreover, grade (education level) instead of age, sex and ethnicity was the most essential risk factor for prevalence of overall myopia (OR = 1.844, 95% CI: 1.605-2.119), and an increase of prevalence by 84.4% per grade was seen. Furthermore, similar associations of grade were significant with low myopia (OR = 1.613, 95% CI: 1.385-1.877) and moderate myopia (OR = 2.186, 95% CI: 1.693-2.823), meanwhile, prevalence of low myopia and moderate myopia demonstrated an increase of prevalence by 61.3 and 118.6% per grade, respectively. None of the factors included in the present study was significant risk factor for high myopia.

Conclusions

The present study investigated a non-negligible high prevalence of myopia among primary-school students in Xi'an, north-western of China, and a gradual increasing in proportion with education level.

Myopia progression and associated factors of refractive status in children and adolescents in Tibet and Chongqing during the COVID-19 pandemic

Objectives

To investigate myopia progression and associated factors of refractive status among children and adolescents in Tibet and Chongqing in China during the COVID-19 pandemic.

Methods

A population-based cross-sectional study was conducted to compare rates of myopia and high myopia, axial length (AL), spherical equivalent (SE), outdoor activity time, digital device use, and frequency of visual examinations for children and adolescents affected by myopia in Chongqing and Tibet in 2021.

Results

A total of 2,303 students from Chongqing and 1,687 students from Tibet were examined. The overall prevalence of myopia and high myopia in these two groups were 53.80 and 7.04% vs. 43.86 and 1.30%, respectively in each case. The Chongqing students had a longer AL than the group from Tibet (23.95 vs. 23.40 mm, respectively; p < 0.001). The mean SE of the students with myopic parents in Tibet was lower than that of the students in Chongqing with myopic parents (-2.57 ± 2.38 diopters (D) vs. -2.30 ± 2.34 D, respectively) (p < 0.001). Conversely, the mean SE of the students from urban areas in Chongqing was lower than that of the students in Tibet (-2.26 ± 2.25 D vs. -1.75 ± 1.96 D, respectively; p < 0.001). The Chongqing students exhibited lower SE (-2.44 ± 2.22 D) than their Tibetan counterparts (mean SE: -1.78 ± 1.65 D (p = 0.0001) when spending more than 2.5 h outdoors. For example, 61.35% of the students in Tibet spent more than 2.5 h outdoors daily, compared with 43.04% of the students in Chongqing. Correspondingly, the proportion of students using digital devices in Tibet (64.43%) was lower than that in Chongqing (100%). For the latter, 38.62% of the students in Chongqing spent more than 2.5 h online using digital devices compared to 10.49% of the students in Tibet. Greater monitoring of visual status was observed for the Chongqing students (mean SE: -1.90 ± 1.98 D) compared with students in Tibet (mean SE: -2.68 ± 1.85 D) (p = 0.0448), with the frequency of optimal examinations being every 6 months. Outdoor activity time was identified as a common risk factor for myopia in both of the populations examined, with odds ratios (ORs) of 1.84 (95% CI: 1.79-1.90) in Chongqing and 0.84 (95% CI: 0.73-0.96) in Tibet. Digital screen time was associated with myopia and high myopia in Chongqing, with ORs of 1.15 (95% CI: 1.08-1.22) and 1.06 (95% CI: 0.94-1.77), respectively. Digital screen time was also found to be a risk factor for high myopia in Tibet (OR: 1.21, 95% CI: 0.77-1.61). The type of digital devices used was also associated with myopia and high myopia in Tibet (OR: 1.33, 95% CI: 1.06-1.68 and OR: 1.49, 95% CI: 0.84-2.58, respectively). Finally, examination frequency was found to correlate with high myopia in the Tibet group (OR: 1.79, 95% CI: 0.66-2.71).

Conclusion

Based on our data, we observed that the prevalence of refractive errors in children and adolescents was significantly lower in Tibet than in Chongqing. These results are potentially due to prolonged outdoor activity time, and the type and time of use for digital devices that characterize the group of children and adolescents from Tibet. It is recommended that parents and children in Chongqing would benefit from increased awareness regarding myopia progression and its prevention.

Efficacy and safety of traditional Chinese medicine decoction in the treatment of adolescent myopia: A protocol for systematic review and network meta-analysis

BACKGROUND

Adolescent myopia has become a major public health problem in Asian countries and even the world. Due to its unstable prognosis and numerous complications, it has caused serious social and economic burden. As a common treatment in Asia, Chinese medicine has been shown to be effective in controlling the development of myopia, but its evidence-based medical evidence is not sufficient. Therefore, the purpose of this study is to evaluate the efficacy and safety of traditional Chinese medicine (TCM) in the treatment of adolescent myopia through network meta-analysis, and to provide evidence for clinical and scientific research.

METHODS

We searched seven databases for randomized controlled trials of TCM decoction for adolescent myopia, including PubMed, the Cochrane Library, EMbase, China National Knowledge Infrastructure, China Biological Medicine, Chinese Scientific Journals Database, and wan-fang databases, from the date of the establishment of each database to January 31, 2022. The network meta-analysis will be implemented through Aggregate Data Drug Information System 1.16.8 and Stata 13.0 software. Primary outcomes include distant vision, intraocular pressure, and diopter. Mean differences or odds ratios will be used for statistical analysis. We will ensure the reliability of the results through node-split model and heterogeneity analysis. In addition, the Cochrane Collaboration's tool and Grading of Recommendations Assessment, Development and Evaluation system will be used for the methodological quality and the evidence quality.

RESULTS

This study will provide reliable evidence for the clinical selection of TCM decoction in the treatment of adolescent myopia.

CONCLUSION

The results of this study will evaluate the efficacy and safety of TCM decoction in the treatment of adolescent myopia, and provide decision-making references for future clinical and scientific research.

ETHICS AND DISSEMINATION

This study did not require ethical approval. We will disseminate our findings by publishing results in a peer-reviewed journal.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/VXQUP.

Prevalence and risk factors for myopia and high myopia: A cross-sectional study among Han and Uyghur students in Xinjiang, China

PURPOSE

This study aimed to investigate the prevalence and risk factors for myopia and high myopia among Han and Uyghur students in Xinjiang, China.

METHODS

This cross-sectional study with a multistage, stratified cluster sampling method was completed in Xinjiang, China. Visual acuity and noncycloplegic refraction were measured. The crude and sex- and age-adjusted prevalence of myopia and high myopia in Han and Uyghur students were compared. Multivariate logistic regression analyses were applied to identify risk factors associated with myopia and high myopia.

RESULTS

In total, 84,033 participants were included in the final analysis, comprising 64,110 Han and 19,923 Uyghur participants. The overall age- and sex-adjusted prevalence of myopia and high myopia were 47.70% (95% CI: 47.67-47.74) and 2.55% (95% CI: 2.54-2.56), respectively. Compared to the Uyghur population, the Han population had a higher prevalence of myopia (63.59% vs. 21.34%, p < 0.0001) and high myopia (4.68% vs. 0.6%, p < 0.0001). Han ethnicity, age, female sex, higher education level and living in urban areas were found to be positively associated with myopia and high myopia. Living in northern Xinjiang was found to be positively associated with myopia but negatively associated with high myopia.

CONCLUSIONS

Our study investigated the prevalence of myopia and high myopia among Han and Uyghur students aged 4-23 years in Xinjiang, China. The Han population had a higher prevalence of myopia and high myopia than the Uyghur population. However, the prevalence of myopia among the Uyghur population showed a more remarkable increasing trend than that among the Han population in Xinjiang.

Use baseline axial length measurements in myopic patients to predict the control of myopia with and without atropine 0.01

PURPOSE

Identifying axial length growth rate as an indicator of fast progression before initiating atropine 0.01% for myopia progression in children.

METHOD

From baseline, axial length growth over six months was measured prospectively. Subjects were then initiated on atropine 0.01% if axial length growth was greater than 0.1mm per 6 months (fast progressors), axial length and spherical equivalent change measurements recorded every six months. The rate of change was compared to the baseline pre-treatment rate. If axial length change was below the threshold, subjects received monitoring only.

RESULTS

73 subjects were identified as fast progressors and commenced atropine 0.01%, (mean baseline refraction of OD -2.9±1.6, OS -2.9±1.8 and a mean baseline axial length OD 24.62 ± 1.00 mm, OS 24.53 ± 0.99 mm). At six months, the mean paired difference of axial length growth rate was significantly reduced by 50% of baseline (all 73 subjects, p<0.05). 53 subjects followed to 12 months, and 12 to 24 months maintained a reduced growth rate. Change in mean spherical equivalent was significantly reduced compared to pre-treatment refractive error (mean paired difference p<0.05) and at each subsequent visit. 91 children were slow progressors and remained untreated. Their axial length growth rate did not change significantly out to 24 months. Spherical equivalent changed less than -0.5D annually in this group.

CONCLUSION

Identifying fast progressors before treatment initiation demonstrated a strong treatment effect with atropine 0.01% reducing their individual rate of myopia progression by 50%. Another large group of myopic children, slow progressors, continued without medical intervention. A baseline axial length growth rate is proposed as a guideline to identify fast progressors who are more likely to benefit from atropine 0.01%.

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.

Association of Myopia and Genetic Variants of TGFB2-AS1 and TGFBR1 in the TGF-β Signaling Pathway: A Longitudinal Study in Chinese School-Aged Children

Background

Myopia is a complex multifactorial condition which involves several overlapping signaling pathways mediated by distinct genes. This prospective cohort study evaluated the associations of two genetic variants in the TGF-β signaling pathway with the onset and progression of myopia and ocular biometric parameters in Chinese school-aged children.

Methods

A total of 556 second grade children were examined and followed up for 3.5 years. Non-cycloplegic refraction and ocular biometric parameters were measured annually. Multivariate regression analysis was used to assess the effect of the TGFBR1 rs10760673 and TGFB2-AS1 rs7550232 variants on the occurrence and progression of myopia. A 10,000 permutations test was used to correct for multiple testing. Functional annotation of single nucleotide polymorphisms (SNPs) was performed using RegulomeDB, HaploReg, and rVarBase.

Results

A total of 448 children were included in the analysis. After adjustments for gender, age, near work time and outdoor time with 10,000 permutations, the results indicated that the C allele and the AC or CC genotypes of rs7550232 adjacent to TGFB2-AS1 were associated with a significantly increased risk of the onset of myopia in two genetic models (additive: P’ = 0.022; dominant: P’ = 0.025). Additionally, the A allele and the AA or AG genotypes of rs10760673 of TGFBR1 were associated with a significant myopic shift (additive: P’ = 0.008; dominant: P’ = 0.028; recessive: P’ = 0.027). Furthermore, rs10760673 was associated with an increase in axial length (AL) (P’ = 0.013, β = 0.03) and a change in the ratio of AL to the corneal radius of curvature (AL/CRC) (P’ = 0.031, β = 0.003). Analysis using RegulomeDB, HaploReg, and rVarBase indicated that rs7550232 is likely to affect transcription factor binding, any motif, DNase footprint, and DNase peak.

Conclusion

The present study indicated that rs10760673 and rs7550232 may represent susceptibility loci for the progression and onset of myopia, respectively, in school-aged children. Associations of the variants of the TGFBR1 and TGFB2-AS1 genes with myopia may be mediated by the TGF-β signaling pathway; this hypothesis requires validation in functional studies. This trial was registered as ChiCTR1900020584 at www.Chictr.org.cn.

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.

Prevalence and Time Trends in Myopia Among Children and Adolescents

BACKGROUND

Myopia (near-sightedness) is increasing worldwide, especially in Asia. The aim of this study was to describe trends in the prevalence of myopia in Germany.

METHODS

We analyzed data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS; baseline survey 2003-2006, N = 17 640; wave 2, 2014-2017, N = 15 023). The presence of myopia was determined from a parent questionnaire and validated by the use of a visual aid. The population prevalence of myopia was calculated. Based on the KiGGS wave 2 data, potential risk factors for myopia were identified by means of logistic regression.

RESULTS

The prevalence of myopia at the age of 0-17 years in Germany was 11.6% (95% confidence interval [11.0; 12.2]) in the period 2003-2006 and 11.4% [10.7; 12.2] in 2014-2017. No age group of either sex exhibited a relevant, statistically significant change in the prevalence of myopia. In the adjusted model (adjusted for age, sex, family socioeconomic status, family history of migration), no association was found between myopia and use of digital media. More time spent reading books was associated with myopia: reading for more than 2 h/day showed an odds ratio of 1.69 [1.3; 2.2].

CONCLUSION

The prevalence of myopia in children and adolescents in Germany has remained virtually unchanged over a period of approximately 10 years. Changes in media consumption, such as the increased use of smartphones in this age group, have therefore had no detectable impact on the development of myopia, at least not so far. Future studies should investigate the influences of further increases in media use and examine the long-term effects.

Recent Epidemiology Study Data of Myopia

Myopia, a pandemic refractive error, is affecting more and more people. The progression of myopia could cause numerously serious complications, even leading to blindness. This review summarizes the epidemiological studies on myopia after 2018 and analyzes the risk factors associated with myopia. The prevalence of myopia varies in different regions, age, and observation time. East Asia has been gripped by an unprecedented rise in myopia, and other parts of the world have also seen an increase. The prevalence of myopia in children continues to rise and aggravates with age. The prevalence of high myopia has also increased along with myopia. Racial dependence and family aggregation can be seen frequently in myopia patients. Increased outdoor activities are proven to be protective factors for myopia, as near-distance work and higher education levels affect in the opposite. The impact of gender or urbanization on myopia is controversial. The relationship between nutrition, digital screens, Kawasaki disease, pregnant women smoking during pregnancy, and myopia is still not clear for lack of sufficient evidence. Understanding the various factors that affect myopia helps to clarify the mechanism of myopia formation and also to formulate reasonable prevention and control measures of myopia to protect people's health, especially for adolescents.