Factors associated with myopia in Korean children: Korea National Health and nutrition examination survey 2016-2017 (KNHANES VII)

Contemporary Patterns and Underlying Causes of Vitrectomy in Pediatric and Adolescent Patients: A Nationwide, Population-Based Analysis

PURPOSE

We determined the incidence, etiology, and longitudinal trends of vitreoretinal diseases necessitating pars plana vitrectomy (PPV) in the pediatric and adolescent population.

DESIGN

Nationwide, population-based cohort study.

METHODS

This study utilized data extracted from the Korean National Health Claims database spanning from 2009 to 2020. All pediatric and adolescent patients (under 20 years of age) who underwent PPV across the Korean population were included. The cumulative incidence of PPV was estimated from 2009 to 2020, with 2009 to 2011 as the washout period. The annual trends of PPV incidence, the proportion of each etiology, and comorbidity were estimated based on sex and specific age groups.

RESULTS

In total, 1913 patients, including 83 infants, 746 pediatric patients, and 1084 adolescents, were newly identified as having undergone PPV surgery. The cumulative incidence of PPV surgery per 100,000 individuals was 21.42 (95% CI, 21.41-21.43). The rate of PPV was 2.4 times higher for males than females, and the rate of trauma as a comorbidity was also higher for males than females (13.1% vs 4.8%). Among males aged 5 years and older, the incidence of PPV nearly halved from 2011 to 2020. Among the primary etiologies, ROP had the highest rate (72%) in infants (under 1 year), while RD was most common (63%) in individuals aged 5 to 19 years. Myopia was present in 30.3% of patients, and atopic dermatitis was present in 31.8% of all patients.

CONCLUSION

The primary etiologies underlying the need for PPV in the pediatric and adolescent populations vary by sex and age group. The incidence of PPV continues to decline in the adolescent population. Therefore, tailored patient education and age-specific etiological examination are recommended.

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.

Prevalence of and risk factors for myopia among urban and rural children in Northeast China: protocol for a school-based cross-sectional study

INTRODUCTION

The worldwide prevalence of myopia is high and continues to increase. In this study, a school screening programme for myopia will be implemented using the whole-process information method. The purpose of this study is to investigate the prevalence of myopia in urban and rural areas of Northeast China and to determine the factors related to myopia.

METHODS AND ANALYSIS

This is a school-based cross-sectional study. Our study population will include 6000 school-aged children from 2 urban and 2 rural schools in Jinzhou, China. The study will be conducted using our self-developed internet-based intelligent data collection, transmission, storage and analysis system. Examination parameters include uncorrected distance visual acuity, presenting distance visual acuity, non-cycloplegic autorefraction, height, weight, waist circumference, hip circumference, spinal curvature and dental caries. The examination report will be automatically sent to parents, who will complete the questionnaire, and appropriate statistical analysis will be performed. The main outcome is the prevalence of myopia, defined as an equivalent spherical degree ≤-0.5 D.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Third Affiliated Hospital of Jinzhou Medical University (number: JYDSY-KXYJ-IEC-2023-018). Findings will be published in a peer-reviewed journal. Subjects and their parents (or other authorised agents) give informed consent prior to study participation.

TRIAL REGISTRATION NUMBER

ChiCTR2300072893.

Association between weight-adjusted waist index and myopia in adolescents and young adults: results from NHANES 1999-2008

BACKGROUND

Previous studies have indicated a possible link between obesity and myopia, although the results have varied. The objective of this study was to investigate the correlation between a new measure of obesity, the weight-adjusted waist index (WWI), and myopia.

METHOD

This cross-sectional study included individuals between the ages of 12 and 25 who participated in a noncycloplegic vision examination as part of the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2008. WWI was calculated as waist circumference divided by the square root of body weight. Myopia was characterized by a spherical equivalent (SE) of ≤ - 0.5 diopters (D) and further categorized into mild (-3.00D < SE≤-0.50 D), moderate (-6.00D < SE ≤-3.00 D), or high (SE≤-6.00 D). We utilized a weighted multivariable logistic regression and a generalized additive model to evaluate the correlation between WWI and myopia. Threshold effects were analyzed, and we performed subgroup analysis and interaction tests.

RESULTS

A grand total of 11,180 individuals were registered for the study. Decreased myopia severity was observed with higher WWI, as evidenced by elevated SE (β = 0.098, 95% CI: 0.028-0.167). Individuals in the top tertile of WWI experienced a 19.8% decrease in risk compared to those in the lowest group (OR = 0.802, 95% CI: 0.800-0.804; P for trend < 0.001). Similar associations were observed for high myopia. Gender-specific nonlinear associations were found, with different breakpoints for males (10.774) and females (10.025). In males, a significant positive association was found on the right side of the breakpoint (OR = 1.398, 95% CI: 1.038-1.884), while no significant association was found on the left side. Conversely, among females, a negative association was observed on the left side of the breakpoint (OR = 0.679, 95% CI: 0.512-0.899), whereas no notable correlation was detected on the right side.

CONCLUSION

Increased WWI level was linked to a lower risk of myopia and high myopia in the overall sample, with gender-specific variations.

Longitudinal analysis of refraction and ocular biometrics in preschool children with early-onset high myopia

We investigated changes in refraction and ocular biometrics in preschool children with early-onset high myopia. Sixty eyes of 60 children with a mean follow-up time of 58.5 months were included in this study. At baseline, mean age of children was 55.6 ± 13.1 months, mean spherical equivalent (SE) was - 8.59 ± 2.66 D, and 25.64 ± 1.16 mm for axial length (AL). The total annual rate of myopic progression and axial elongation were - 0.37 ± 0.39 D/year and 0.33 ± 0.18 mm/year, respectively. During follow-up period, there was a trend toward less myopic progression and axial elongation over time. Of the total participants, 24 children (40%) were in the myopia progression group and the remaining 36 children (60%) were in the myopia stability group. In multiple linear regression analysis, baseline SE and AL were independently associated with myopic progression, while age, sex, and baseline AL-to-CR ratio were not related to myopic progression. According to the model, more myopic SE (β = - 0.186, P = 0.035) and longer AL (β = - 0.391, P = 0.008) at baseline were significantly associated with myopic progression. Myopia progression in preschoolers with high myopia tended to be relatively modest, with 60% of subjects exhibited myopic stability. Higher myopic SE, and longer AL at baseline were associated with myopic progression in preschool children with high myopia.

Associations between meeting 24-hour movement guidelines and myopia among school-aged children: A cross-sectional study

BACKGROUND

The Canadian 24-hour movement behavior (24-HMB) guidelines recommend an adequate level of physical activity (PA), a limited amount of screen time (ST), and a sufficient sleep duration (SLP) to promote the healthy development of children. Although the positive effects of adhering to the 24-HMB guidelines have been established for several health parameters, less is known about how adherence to the 24-HMB guidelines relates to the myopia risk (i.e., inability to see distant objects properly). Thus, this study investigated associations between meeting 24-HMB guidelines and myopia risk in school-aged children.

METHOD

Using a questionnaire survey, this cross-sectional study was conducted among parents of school-aged children (5-13 years) in China from 15th September to 15th October 2022, with a total of 1423 respondents with complete data for analysis. Parents reported their child's time spent in moderate-to-vigorous-intensity physical activity (MVPA), SLP, and ST. Multiple logistic regression analyses were performed to examine the associations between measures of PA, ST, and SLP alone and in combination, and the occurrence of myopia.

RESULTS

A relatively low percentage of the children being included in the current study (4.92%) met all 24-HMB guidelines, while 32.46% had myopia. Girls had a significantly higher risk of myopia compared to boys (OR = 1.3, 1.002 to 1.68, p = 0.049). Children of parents without myopia had a lower risk of myopia (OR = 0.45, 0.34-0.59, p < 0.001). Children who lived in urban areas (OR = 1.83, 95% CI 1.33 to 2.52, p < 0.001) or towns (OR = 1.60, 1.03 to 2.47, p = 0.04) had a significantly higher risk of myopia compared to those living in rural areas. Meeting SLP guidelines (OR = 0.50, 95% CI 0.31 to 0.82, p < 0.01), meeting ST + SLP guidelines (OR = 0.47, 95% CI 0.32-0.69, <0.001), and meeting all three guidelines were associated with significantly lower risk of myopia (OR = 0.40, 95% CI 0.20-0.82, p = 0.01). Meeting more 24-HMB guidelines was associated with a reduced risk of myopia.

CONCLUSIONS

Our data suggest that adhering to SLP, ST + SLP, and ST + SLP + PA guidelines is associated with the risk of myopia. Future research investigating dose-response associations, and potential mechanisms, is necessary to achieve a more nuanced understanding of the observed associations.

Orthokeratology for Slowing Myopia Progression in Children: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) on the effects of orthokeratology for slowing myopia progression in children.

METHODS

We performed a specific search on PubMed, Embase, Cochrane Library, Clinical Trials, CNKI, SinoMed, and Wanfang Data for RCTs conducted up to October 1, 2022. We pooled the weighted mean difference (WMD) between the orthokeratology and control groups for axial length (AL) elongation and the odds ratio (OR) for rates of adverse events and dropout.

RESULTS

Seven RCTs involving 655 eyes were included. There were significant differences in the effects of orthokeratology versus control in slowing AL elongation with WMD of -0.11 mm (95% confidence interval (CI), -0.13 to -0.08; P <0.01) at 6 months, -0.16 mm (95% CI, -0.18 to -0.13; P <0.01) at 12 months, -0.23 mm (95% CI, -0.29 to -0.18; P <0.01) at 18 months, and -0.28 mm (95% CI, -0.38 to -0.19; P <0.01) at 24 months, respectively. Myopia control rate declined, with 64%, 53%, 50%, and 47% recorded for 6, 12, 18, and 24 months, respectively. There was no statistical significance for adverse events between orthokeratology and control groups (OR=2.63, 95% CI, 0.72-9.61; P =0.11).

CONCLUSION

Orthokeratology can effectively slow myopia progression in children, and the efficacy of myopia control decreases with time.

Associations between anthropometric indicators and refraction in school-age children during the post-COVID-19 era

Purpose

To explore the associations between anthropometric indicators and refraction in school-aged children in the post-COVID-19 era.

Methods

Data were collected from 25,644 children aged 7 to 12 years in 48 elementary schools in Tianjin. The comprehensive examination included height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), refraction, and calculation of BMI, with a follow-up visit after 6 months. Myopia was defined as spherical equivalent refraction (SER) ≤-0.50 diopter (D). Bivariate correlation coefficients and multiple linear regression models were used to explore the cross-sectional and longitudinal associations between anthropometric indicators (height, weight, BMI, SBP, and DBP) and refraction.

Results

The mean changes in height, weight, BMI, SBP, DBP, and SER of the participants were 4.03 ± 2.18 cm, 3.10 ± 2.39 kg, 0.45 ± 1.16 kg/m², 2.26 ± 14.74 mmHg, 2.18 ± 11.79 mmHg and -0.17 ± 0.51 D, respectively. Overall, height, weight, BMI, SBP, and DBP were all correlated with SER (r = -0.324, r = -0.234, r = -0.121, r = -0.112, r = -0.066, both p < 0.001), and changes in height and weight were correlated with changes in SER (r = -0.034, -0.031, both p < 0.001). Furthermore, multiple linear regression analysis revealed that the association of BMI, SBP, and DBP with SER was significant in myopic children but not in non-myopic children. The association between changes in weight and changes in SER was only present in non-myopic children but not in myopic children.

Conclusion

Height and weight were negatively correlated with SER in both cross-sectional analysis and longitudinal changes, indicating that children's height, weight and growth rate may be used as a reference indicator for myopia risk prediction and myopia progression monitoring.

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.

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.

Effects of Axial Lengths in High Myopia on the Significance Maps of Optical Coherence Tomography

Purpose: We corrected the axial lengths of the macular and peripapillary significance maps using software embedded in a commercial spectral domain optical coherence tomography (SD-OCT) package. We evaluated the accuracy of glaucoma diagnosis in patients with high myopia, and the clinical implications.Methods: Seventy eyes of 70 highly myopic patients with or without normal-tension glaucoma were retrospectively reviewed. The sensitivities and specificities of the color-coded significance maps were calculated using 1% (red) or 5% (yellow) as the abnormality criteria, and the values compared before and after axial length corrections performed using embedded SD-OCT software.Results: At the 1% level of the normative database, we found no significant difference in specificity or sensitivity. At the 5% level, the increase in specificity was significant only for the inferotemporal sectors of the macular significance map. The specificity of the inferotemporal sector of the inner scan circle increased from 61.9 to 78.6% (p = 0.016) and that of the outer scan circle from 69 to 83.8% (p = 0.031). The specificities of the entire chart, the superior sector of the superior/inferior chart, and the 12-clockwise map increased significantly from 54.8 to 78.6% (p = 0.002), 59.5 to 76.2% (p = 0.039), and 59.5 to 76.2% (p = 0.002) respectively.Conclusions: Clinicians should note that axial length correction of significance maps reduces the false-positive glaucoma diagnostic rates in highly myopic eyes. Correction of significance maps using embedded software may thus aid clinicians in the diagnosis of glaucoma in high myopic eyes.

The Role of Atropine in Preventing Myopia Progression: An Update

Several approaches have been investigated for preventing myopia progression in children and teenagers. Among them, topical atropine has shown promising results and it is being adopted in clinical practice more and more frequently. However, the optimal formulation and treatment algorithm are still to be determined. We discuss the pharmacokinetic, pharmacodynamic, clinical, and tolerability profile revealed first by the multicenter, randomized ATOM 1 and 2 trials and, more recently, by the LAMP Study. Results from these trials confirmed the efficacy of low-concentration atropine with a concentration-dependent response. Although atropine at 0.025% and 0.05% concentrations has shown the most encouraging results in large-scale studies, these formulations are not yet commonplace in worldwide clinical practice. Moreover, their rebound effect and the possibility of reaching a stabilization effect have not been fully investigated with real-life studies. Thus, further larger-scale studies should better characterize the clinical efficacy of atropine over longer follow-up periods, in order to define the optimal dosage and treatment regimen.

Obesity and high myopia in children and adolescents: Korea National Health and Nutrition Examination Survey

Purpose

The prevalence of both obesity and myopia are increasing in Korean children and adolescents. The purpose of this study is to examine the impact of obesity on the prevalence of myopia in Korean children and adolescents.

Methods

This study used the data of a nationally representative cross-sectional survey, the Korea National Health and Nutrition Examination Survey (KNHANES) VII conducted from 2016 to 2018. Of the 1237 children and adolescents aged 5–18 years who participated in the KNHANES VII and underwent ophthalmologic examinations for the survey, 1114 were selected for review, excluding those whose data on refractive error, family history of myopia, or waist circumference were missing. Body mass index (BMI) was classified into four groups: underweight (< 5th percentile), normal weight (≥ 5th percentile, < 85th percentile), overweight (≥ 85th percentile, < 95th percentile), and obese (≥ 95th percentile). Myopia was defined by the level of refractive error ≤ -0.5 diopters (D) and classified as mild (≤ -0.5 D, > -3.0 D), moderate (≤ -3.0 D, > -6.0 D), or high (≤ -6.0 D) myopia. The relationship between BMI and myopia was analyzed using complex sample logistic regression. Age and family history were corrected followed by an analysis of the odds ratios.

Results

Compared to those with normal weights (controls), being underweight, overweight, or obese showed no significant odds of developing mild and moderate myopia. Conversely, when compared with that of controls, the odds ratio of developing high myopia in the underweight, overweight, and obese groups was 0.77 (95% CI, 0.22–2.65), 1.37 (95% CI, 0.51–3.66), and 3.77 (95% CI, 1.98–7.16), respectively. Furthermore, in a separate analysis by sex and BMI, the odds ratio of developing high myopia was 2.84 (95% CI, 1.10–7.35) in boys with obesity and 4.23 (95% CI,1.19–15.09) and 5.04 (95% CI,1.77–14.34) in overweight and obese girls, respectively.

Conclusions

An association exists between obesity in childhood and adolescence and high myopia. Being overweight in girls was also found to be associated with high myopia. Thus, efforts to maintain a healthy weight during childhood and adolescence are of great importance.

Association between tinnitus and depressive symptoms in the South Korean population

In this study, we aimed to examine the association between tinnitus and depressive symptoms in middle-aged and elderly South Korean population. The participants were selected from among those who participated in the 2014, 2016, and 2018 Korea National Health and Nutrition Examination Surveys. The incidence and severity of tinnitus was assessed using a self-reported questionnaire, while depressive symptoms were evaluated using self-reported Patient Health Questionnaire-9. Multiple logistic regression was performed to examine the association between tinnitus and depressive symptoms. Overall, 10 979 (4821 men and 6158 women) participants were enrolled in the study. Regardless of sex, individuals who reported having tinnitus were more likely to have depressive symptoms than those without tinnitus (men: odds ratio 1.53, 95% confidence interval 1.01–2.32; women: odds ratio 1.78, 95% confidence interval 1.35–2.35). In severe cases of tinnitus, women were more likely to have depressive symptoms (odds ratio 7.18, 95% confidence interval 3.71–13.87) compared to men. This study revealed a significant association between tinnitus and depressive symptoms among the middle-aged and elderly South Korean population.

Design, methodology, and baseline of whole city-million scale children and adolescents myopia survey (CAMS) in Wenzhou, China

Background

Myopia is the most common visual impairment in children and adolescents worldwide. This study described an economical and effective population-based screening pipeline and performed the project of a million scale children and adolescents myopia survey (CAMS), which will shed light on the further study of myopia from the level of epidemiology and precision medicine.

Methods

We developed a novel population-based screening pattern, an intelligent screening process and internet-based information transmission and analysis system to carry out the survey consisting of school children in Wenzhou, China. The examination items include unaided distance visual acuity, presenting distance visual acuity, and non-cycloplegic autorefraction. Myopia and high myopia were defined as spherical equivalent (SE) ≤ − 1.00 diopters (D) and SE ≤ − 6.00 D, respectively. Next, the reports of the vision checking were automatically sent to parents and the related departments. The CAMS project will be done two to four times annually with the support of the government. An online eyesight status information management system (OESIMS) was developed to construct comprehensive and efficient electronic vision health records (EVHRs) for myopia information inquiry, risk pre-warning, and further study.

Results

The CAMS completed the first-round of screening within 30 days for 99.41% of Wenzhou students from districts and counties, in June 2019. A total of 1,060,925 participants were eligible for CAMS and 1,054,251 (99.37% participation rate) were selected through data quality control, which comprised 1305 schools, and 580,609, 251,050 and 170,967 elementary, middle, and high school students. The mean age of participants was 12.21 ± 3.32 years (6–20 years), the female-to-male ratio was 0.82. The prevalence of myopia in elementary, middle, and high school students was 38.16%, 77.52%, and 84.00%, respectively, and the high myopia incidence was 0.95%, 6.90%, and 12.98%.

Conclusions

The CAMS standardized myopia screening model involves automating large-scale information collection, data transmission, data analysis and early warning, thereby supporting myopia prevention and control. The entire survey reduced 90% of staff, cost, and time consumption compared with previous surveys. This will provide new insights for decision support for public health intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40662-021-00255-1.

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.

Association of blepharoptosis with refractive error in the Korean general population

BACKGROUND/OBJECTIVES

We investigated the effect of blepharoptosis on refractive errors across different age groups in Korean population.

SUBJECTS/METHODS

This cross-sectional study was performed with data obtained in the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2012. A total of 33,103 participants were enroled in our study. Blepharoptosis was defined as a marginal reflex distance 1 (MRD1) less than 2 mm, and was diagnosed in 3,305 (9.98%) participants. Ophthalmic examinations were performed, including measurements of MRD1, spherical equivalent, and degree of astigmatism. The age range was divided into three groups: less than 20 years old; more than 20 years and less than 60 years old; and more than 60 years old.

RESULTS

The mean spherical equivalent were -0.28 ± 2.23 D in the ptotic eyelids and -1.13 ± 2.30 D in the non-ptotic eyelids (p < 0.001, 95% CI: -0.93, -0.77). The mean cylinder dioptre were -1.03 ± 0.87 D and -0.80 ± 0.77 D respectively (p < 0.001, 95% CI: 0.20, 0.26). The association with the eyelid position and refractive error significantly differed according to the age group and body mass index. Increased positive spherical change and increased astigmatism were prominent among ptotic participants aged less than 60 years.

CONCLUSIONS

A decrease in MRD1 was associated with a hyperopic shift and higher astigmatism. Mechanical compression of the ptotic eyelid may affect ocular biometry, with the effect being particularly prominent in younger participants who had greater eyelid tension.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

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.

Evolution of the Prevalence of Myopia among Taiwanese Schoolchildren: A Review of Survey Data from 1983 through 2017

PURPOSE

The aim of this study was to evaluate the changes in the prevalence of myopia in Taiwanese schoolchildren over the past few decades and to analyze the risk factors for myopia.

DESIGN

Analysis of 8 consecutive population-based myopia surveys conducted from 1983 through 2017.

PARTICIPANTS

An average of 8917 (5019-11 656) schoolchildren 3 to 18 years of age were selected using stratified systematic cluster sampling or by probability proportional to size sampling.

METHODS

All participants underwent complete ophthalmic evaluations. Three drops of 0.5% tropicamide were used to obtain the cycloplegic refractive status of each participant. Questionnaires were used to acquire participant data from the 1995, 2005, 2010, and 2016 surveys.

MAIN OUTCOME MEASURES

Prevalence of myopia (spherical equivalence of ≤-0.25 diopter [D]) and high myopia (≤-6.0 D) was assessed. Multivariate analyses of risk factors were conducted.

RESULTS

The prevalence of myopia among all age groups increased steadily. From 1983 through 2017, the weighted prevalence increased from 5.37% (95% confidence interval [CI], 3.50%-7.23%) to 25.41% (95% CI, 21.27%-29.55%) for 7-year-olds (P = 0.001 for trend) and from 30.66% (95% CI, 26.89%-34.43%) to 76.67% (95% CI, 72.94%-80.40%) for 12-year-olds (P = 0.001 for trend). The prevalence of high myopia also increased from 1.39% (95% CI, 0.43%-2.35%) to 4.26% (95% CI, 3.35%-5.17%) for 12-year-olds (P = 0.008 for trend) and from 4.37% (95% CI, 2.91%-5.82%) to 15.36% (95% CI, 13.78%-16.94%) for 15-year-olds (P = 0.039 for trend). In both the 2005 and 2016 survey samples, children who spent less than 180 minutes daily on near-work activities showed significantly lower risks for myopia developing (<60 minutes: odds ratio [OR], 0.48 and 0.56; 60-180 minutes: OR, 0.69 and 0.67). In the 2016 survey, spending more than 60 minutes daily on electronic devices was associated significantly with both myopia and high myopia (OR, 2.43 and 2.31).

CONCLUSIONS

The prevalence of myopia among schoolchildren increased rapidly from 1983 through 2017 in Taiwan. The major risk factors are older age and time spent on near-work activities. Use of electronic devices increased the amount of time spent on near-work and may increase the risk of developing myopia.