Education-Related Parameters in High Myopia: Adults versus School Children

Seasonal Variations in Ocular Axial Length Increase among Children in the Czech Republic

In recent decades, the prevalence of myopia has increased worldwide as well as in European countries, and it has become an important medical and socioeconomic problem. Our prospective single-center study analysed the changes in ocular axial length (AXL) in a population of Central European schoolchildren from 2016 to 2019. The study included 528 eyes of 264 children with a mean age of 12.2 years at the beginning of the study. Visual acuity, ocular AXL, anterior chamber depth, and the questionnaire were examined at 6-month intervals (in spring and autumn, following the winter and summer periods, respectively). The average ocular AXL was 23.329 mm (median: 23.315 mm) at the beginning of the study and 23.525 mm (median: 23.505 mm) at the end of the study. The change in ocular AXL per month was significantly higher (p < 0.0001) during the winter period (average: 0.013 mm, median: 0.011 mm) than during the summer period (average: -0.001 mm, median: 0.000 mm). We observed a significantly higher increase in ocular AXL in a Caucasian population during the winter period (with lower daylight exposure) than the summer period.

Prevalence of Refractive Error in Vientiane Province, Lao People's Democratic Republic

PURPOSE

To determine the prevalence of adult refractive error and associated risk factors in the Vientiane Province of the Lao People's Democratic Republic.

METHODS

Population-based, cross-sectional ophthalmic survey of individuals ≥ 40 years of age in Vientiane Province. Suitable refractive data was available in 1058 individuals. Demographic data, which included age and gender, was obtained from all participants. Smoking status, presence of diabetes and hypertension was also recorded. The ophthalmic examination included autorefraction, grading of cataract, applanation tonometry and ultrasound pachymetry for ocular biometry, including axial length.

RESULTS

Mean refractive error measured -0.36 diopters (D) (standard deviation [SD], 1.41) and mean cylindrical error measured -0.33 D (SD 0.95). Myopia ≤ -0.5 D and ≤ -5.0 D occurred in 53.2% (95% confidence interval [CI]: 43.7 to 62.6) and 2.0% (95% CI: 0.4 to 3.6) of participants, respectively. There was a correlation between myopia and both age and higher grading of nuclear cataract (p < .001). Hyperopia ≥ +0.5 D was present in 26.4% of participants and was associated with increasing age (p < .001). Astigmatism was present in 55.8% (95% CI: 51.5 to 60.2) of the population and was associated with increased nuclear cataract (p < .001). Urban participants had a reduced prevalence of myopia compared with rural participants.

CONCLUSION

Myopia was associated with younger age and a higher grade of nuclear cataract. The prevalence of myopia in the adult population of Vientiane Province was higher than that reported in neighbouring Asian regions and contributed to low vision.

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.

Temporal trends in frequency, type and severity of myopia and associations with key environmental risk factors in the UK: Findings from the UK Biobank Study

This study investigated temporal trends in the epidemiology of primary myopia and associations with key environmental risk factors in a UK population. Data were collected at recruitment (non-cycloplegic autorefraction, year of birth, sex, ethnicity, highest educational attainment, reason and age of first wearing glasses and history of eye disease) from 107,442 UK Biobank study participants aged 40 to 69 years, born between 1939 and 1970. Myopia was defined as mean spherical equivalent (MSE) ≤-1 dioptre (D). Temporal changes in myopia frequency by birth cohort (5-year bands using date of birth) and associations with environmental factors were analysed, distinguishing both type (childhood-onset, <18 years versus adult-onset) and severity (three categories: low -1.00 to -2.99D, moderate -3.00 to -5.99D or high ≥-6.00D). Overall myopia frequency increased from 20.0% in the oldest cohort (births 1939–1944) to 29.2% in the youngest (1965–1970), reflecting a relatively higher increase in frequency of adult-onset and low myopia. Childhood-onset myopia peaked in participants born in 1950–54, adult-onset myopia peaked in the cohort born a decade later. The distribution of MSE only shifted for childhood-onset myopia (median: -3.8 [IQR -2.4, -5.4] to -4.4 [IQR -3.0, -6.2]). The magnitude of the association between higher educational attainment (proxy for educational intensity) and myopia overall increased over time (adjusted Odds Ratio (OR) 2.7 [2.5, 2.9] in the oldest versus 4.2 [3.3, 5.2] in the youngest cohort), being substantially greater for childhood-onset myopia (OR 3.3 [2.8, 4.0] to 8.0 [4.2, 13]). Without delineating childhood-onset from adult-onset myopia, important temporal trends would have been obscured. The differential impact of educational experience/intensity on both childhood-onset and high myopia, amplified over time, suggests a cohort effect in gene-environment interaction with potential for increasing myopia frequency if increasing childhood educational intensity is unchecked. However, historical plateauing of myopia frequency does suggest some potential for effective intervention.

Predicting factors for progression of the myopia in the MiSight assessment study Spain (MASS)

PURPOSE

To investigate which baseline factors are predictive for success in controlling myopia progression in a group of children wearing MiSight Contact Lens (CLs).

METHODS

Myopic patients (n=41) fitted with MiSight CLs and followed up two years were included in this study. Bivariate analysis, a logistic regression analysis (LG) and a decision tree (DT) approach were used to screen for the factors influencing the success of the treatment. To assess the response, axial length (AL) changes were considered as main variable. Patients were classified based on a specific range of change of axial length at the end of each year of treatment as "responders" (R) (AL change <0.11mm/per year) and "non-responders" (NR) (AL change ≥0.11mm/per year).

RESULTS

Of a total of forty-one Caucasian patients treated with MiSight CLs, 21 and 16 were considered responders in the first and the second year of follow-up, respectively. LG analysis showed that the only factor associated with smaller axial length growth was more time spent outdoors (p=0.0079) in the first year of treatment. The decision tree analysis showed that in the responding group spending more than 3 and 4h outdoors per week was associated with the best response in the first year and in the second year of treatment respectively.

CONCLUSIONS

The LR and the DT approach of this pilot study identifies time spent outdoors as a main factor in controlling axial eye growth in children treated with MiSight CLs.

Physical Activity Spaces Not Effective against Socioeconomic Inequalities in Myopia Incidence: The Generation R Study

SIGNIFICANCE

Our findings show that non-Dutch background, lower maternal education, and lower net household income level may be new risk factors for myopia development in the Netherlands. Newly introduced physical activity spaces may not be effective enough in increasing outdoor exposure in children to reduce eye growth.

PURPOSE

The aims of this study were to evaluate socioeconomic inequalities in myopia incidence, eye growth, outdoor exposure, and computer use and to investigate if newly introduced physical activity spaces can reduce eye growth in school-aged children.

METHODS

Participants (N = 2643) from the Dutch population-based birth cohort Generation R were examined at ages 6 and 9 years. Socioeconomic inequalities in myopia incidence, eye growth, and lifestyle were determined using regression analyses. Information on physical activity spaces located in Rotterdam was obtained. Differences in eye growth between those who became exposed to new physical activity spaces (n = 230) and those nonexposed (n = 1866) were evaluated with individual-level fixed-effects models.

RESULTS

Myopia prevalence was 2.2% at age 6 years and 12.2% at age 9 years. Outdoor exposure was 11.4 h/wk at age 6 years and 7.4 h/wk at age 9 years. Computer use was 2.1 h/wk at age 6 years and 5.2 h/wk at age 9 years. Myopia incidence was higher in children with non-Dutch background, and families with lower household income and lower maternal education (odds ratio [OR], 1.081 [95% confidence interval, 1.052 to 1.112]; OR, 1.035 [95% confidence interval, 1.008 to 1.063]; OR, 1.028 [95% confidence interval, 1.001 to 1.055], respectively). Children living <600 m of a physical activity space did not have increased outdoor exposure, except those from families with lower maternal education (β = 1.33 h/wk; 95% confidence interval, 0.15 to 2.51 h/wk). Newly introduced physical activity spaces were not associated with reduction of eye growth.

CONCLUSIONS

Children from socioeconomically disadvantaged families became more often myopic than those from socioeconomically advantaged families. We did not find evidence that physical activity spaces protect against myopia for the population at large, but subgroups may benefit.

Who needs myopia control?

Myopia has become a major visual disorder among school-aged children in East Asia due to its rising prevalence over the past few decades and will continue to be a leading health issue with an annual incidence as high as 20%-30%. Although various interventions have been proposed for myopia control, consensus in treatment strategies has yet to be fully developed. Atropine and orthokeratology stand out for their effectiveness in myopia progression control, but children with rapid progression of myopia require treatment with higher concentrations of atropine that are associated with increased rates of side effects, or with orthokeratology that carries risk of significant complication. Therefore, improved risk assessment for myopia onset and progression in children is critical in clinical decision-making. Besides traditional prediction models based on genetic effects and environmental exposures within populations, individualized prediction using machine learning and data based on age-specific refraction is promising. Although emerging treatments for myopia are promising and some have been incorporated into clinical practice, identifying populations who require and benefit from intervention remains the most important initial step for clinical practice.

Axial length and its associations in the Ural Very Old Study

To assess the distribution of axial length as surrogate for myopia and its determinants in an old population, we performed the Ural Very Old Study as a population-based cohort study. Out of 1882 eligible individuals aged 85 + years, the Ural Very Old Study performed in an urban and rural region in Bashkortostan/Russia included 1526 (81.1%) individuals undergoing ophthalmological and medical examinations with sonographic axial length measurement. Biometric data were available for 717 (47.0%) individuals with a mean age of 88.0 ± 2.6 years (range 85–98 years; 25%). Mean axial length was 23.1 ± 1.1 mm (range 19.37–28.89 mm). Prevalences of moderate myopia (axial length 24.5–< 26.5 mm) and high myopia (axial length ≥ 26.5 mm) were 47/717 (6.6%; 95% CI 4.7, 8.4) and 10/717 (1.4%; 95% CI 0.5, 2.3), respectively. In multivariable analysis, longer axial length was associated (coefficient of determination r² 0.25) with taller body height (standardized regression coefficient beta:0.16;non-standardized regression coefficient B: 0.02; 95% confidence interval (CI) 0.01, 0.03; P < 0.001), higher level of education (beta: 0.12; B: 0.07; 95% CI 0.02, 0.11; P = 0.002), and lower corneal refractive power (beta: − 0.35; B: − 0.23; 95% CI − 0.28, − 0.18; P < 0.001). Higher prevalence of moderate myopia, however not of high myopia, was associated with higher educational level (OR 1.39; 95% CI 1.09, 1.68; P = 0.007) and lower corneal refractive power (OR 0.77; 95% CI 0.63, 0.94; P = 0.01). In this old study population, prevalence of moderate axial myopia (6.6% versus 9.7%) was lower than, and prevalence of high axial myopia (1.4% versus 1.4%) was similar as, in a corresponding study on a younger population from the same Russian region. Both myopia prevalence rates were higher than in rural Central India (1.5% and 0.4%, respectively). As in other, younger, populations, axial length and moderate myopia prevalence increased with higher educational level, while high myopia prevalence was independent of the educational level.

PROGRESSION OF MYOPIC MACULOPATHY IN CHINESE CHILDREN WITH HIGH MYOPIA: A Long-Term Follow-Up Study

PURPOSE

To investigate the progression of myopic maculopathy and associated factors in highly myopic Chinese children.

METHODS

In this retrospective observational case series, biometric fundus features were morphometrically measured on photographs. Myopic maculopathy was defined as recommended by the Meta-analysis of Pathologic Myopia Study Group.

RESULTS

The study included 274 children (mean age: 11.7 ± 2.5 years; mean refractive error: -7.66 ± 1.87 diopters [D]) with a mean follow-up of 4.9 ± 1.2 years. Myopic maculopathy progression was detected in 52 eyes (18.9%; 95% confidence interval [CI]: 14.3-23.7%). In multivariable analysis, myopic maculopathy progression was associated with a decrease in refractive error (odds ratio [OR]: 0.72; 95% CI: 0.56-0.92; P < 0.001) (i.e., higher myopization) and enlargement of parapapillary gamma zone (OR: 7.68; 95% CI: 1.63-36.2; P = 0.002). Incident peripapillary diffuse choroidal atrophy, noted in 47 of 236 eyes (20.0%; 95% CI: 14.8-25.2%), was correlated with a decrease in refractive error (OR: 0.70; 95% CI: 0.54-0.92; P = 0.009) (i.e., higher myopization) and greater gamma zone enlargement (OR: 8.28; 95% CI: 1.33-51.7; P = 0.02).

CONCLUSION

Myopia in schoolchildren may have a considerable risk of progressing to myopic maculopathy. Enlargement of parapapillary gamma zone was a main independent risk factor.

Axial length and its relationship to refractive error in Chinese university students

PURPOSE

To investigate the relationship between axial length (AL) and refractive error (RE).

METHODS

Participants comprised Chinese university students. In total, 894 eyes with low hyperopia to emmetropia (-0.50D ≤ spherical equivalent (SE) ≤ +2.00D), and 1007 eyes with moderate to high myopia (-11.00D ≤ SE ≤ -4.00D) were analyzed. Cycloplegic RE and AL were measured with an autorefractor and IOL Master respectively. The association between AL and RE was evaluated by linear regression. Furthermore, differences in the mean AL, as well as the correlation between AL and ocular refraction, were evaluated according to SE, sex, and age.

RESULTS

In both the moderate to high myopia and low hyperopia to emmetropia groups, mean AL was significantly longer in men (26.48 mm, confidence interval (CI) 26.41-26.56 mm; 23.82 mm, CI: 23.76-23.88 mm, respectively) than in women (25.78 mm, CI: 25.71-25.86 mm; 23.25 mm, CI: 23.17-23.33 mm, respectively). For both men and women, mean AL significantly differed among four SE groups (+0.50D < SE ≤ +2.00D, -0.50D ≤ SE ≤ +0.50D, -4.00D ≤ SE ≤ -6.00D, SE < -6.00D, P < 0.001). The correlation coefficient between AL and ocular refraction was -0.318 and -0.277 in male and female participants, respectively, with low hyperopia to emmetropia (-0.50D ≤ SE ≤ +2.00D), and -0.545 and -0.437 in male and female participants, respectively, with moderate to high myopia (-11.00D ≤ SE ≤ -4.00D). There were no age-related effects on SE (P = 0.714) or AL (P = 0.952).

CONCLUSIONS

Ocular refraction is negatively correlated with AL in Chinese university students. The correlation coefficient is greater in those with moderate to high myopia than in those with low hyperopia to emmetropia. Furthermore, the AL is longer in men than in women.

IMI 2021 Reports and Digest - Reflections on the Implications for Clinical Practice

The International Myopia Institute's (IMI) mission is to advance research, education, and management of myopia to decrease future vision impairment and blindness associated with increasing myopia. Its approach is to bring together scientists, clinicians, policymakers, government members, and educators into the field of myopia to stimulate collaboration and sharing of knowledge. The latest reports are on pathologic myopia, the impact of myopia, risk factors for myopia, accommodation and binocular vision in myopia development and progression, and the prevention of myopia and its progression. Together with the digest updating the 2019 International Myopia Institute white papers using the research published in the last 18 months, these evidence-based consensus white papers help to clarify the imperative for myopia control and the role of environmental modification initiatives, informing an evidence-based clinical approach. This guidance includes who to treat and when to start or stop treatment, and the advantages and limitations of different management approaches.

Efficacy in myopia control

There is rapidly expanding interest in interventions to slow myopia progression in children and teenagers, with the intent of reducing risk of myopia-associated complications later in life. Despite many publications dedicated to the topic, little attention has been devoted to understanding 'efficacy' in myopia control and its application. Treatment effect has been expressed in multiple ways, making comparison between therapies and prognosis for an individual patient difficult. Available efficacy data are generally limited to two to three years making long-term treatment effect uncertain. From an evidence-based perspective, efficacy projection should be conservative and not extend beyond that which has been empirically established. Using this principle, review of the literature, data from our own clinical studies, assessment of demonstrated myopia control treatments and allowance for the limitations and context of available data, we arrive at the following important interpretations: (i) axial elongation is the preferred endpoint for assessing myopic progression; (ii) there is insufficient evidence to suggest that faster progressors, or younger myopes, derive greater benefit from treatment; (iii) the initial rate of reduction of axial elongation by myopia control treatments is not sustained; (iv) consequently, using percentage reduction in progression as an index to describe treatment effect can be very misleading and (v) cumulative absolute reduction in axial elongation (CARE) emerges as a preferred efficacy metric; (vi) maximum CARE that has been measured for existing myopia control treatments is 0.44 mm (which equates to about 1 D); (vii) there is no apparent superior method of treatment, although commonly prescribed therapies such as 0.01% atropine and progressive addition spectacles lenses have not consistently provided clinically important effects; (viii) while different treatments have shown divergent efficacy in the first year, they have shown only small differences after this; (ix) rebound should be assumed until proven otherwise; (x) an illusion of inflated efficacy is created by measurement error in refraction, sample bias in only treating 'measured' fast progressors and regression to the mean; (xi) decision to treat should be based on age of onset (or refraction at a given age), not past progression; (xii) the decreased risk of complications later in life provided by even modest reductions in progression suggest treatment is advised for all young myopes and, because of limitations of available interventions, should be aggressive.

Effect of Genetic-Environmental Interaction on Chinese Childhood Myopia

Objective

The purpose of this study was to evaluate the effect of genetic-environmental interaction on myopia in Chinese children aged 6 to 9 years.

Methods

Students had the physical examination and were required to provide basic demographic information. Their families were asked to fill in a questionnaire concerning factors related to myopia. Multiple regression analysis was performed, and adjusted risk ratio values were calculated to assess the role between gene and environment. Value of the environmental and genetic index (EGI) was calculated to demonstrate the effect of genetic-environmental interaction on myopia.

Results

The prevalence of myopia maintained at a high level. EGI was calculated as 0.125 suggesting that genetic factors may play the 12.5% role in the formation of myopia and environmental factors may play a role of 87.5% in the formation of myopia.

Conclusions

For young pupils aged 6 to 9 years, myopia prevalence maintained at a high level, and duration of homework time and staring at electronic screen were the strongest factors associated with myopia. The calculated value of EGI was low, which suggests that environmental factors may play the leading role in the formation of myopia. A long-term follow-up research to improve the accuracy value of EGI is our next job.

Prevalence and predictors of myopic macular degeneration among Asian adults: pooled analysis from the Asian Eye Epidemiology Consortium

AIMS

To determine the prevalence and predictors of myopic macular degeneration (MMD) in a consortium of Asian studies.

METHODS

Individual-level data from 19 885 participants from four population-based studies, and 1379 highly myopic participants (defined as axial length (AL) >26.0 mm) from three clinic-based/school-based studies of the Asian Eye Epidemiology Consortium were pooled. MMD was graded from fundus photographs following the meta-analysis for pathologic myopia classification and defined as the presence of diffuse choroidal atrophy, patchy chorioretinal atrophy, macular atrophy, with or without 'plus' lesion (lacquer crack, choroidal neovascularisation or Fuchs' spot). Area under the curve (AUC) evaluation for predictors was performed for the population-based studies.

RESULTS

The prevalence of MMD was 0.4%, 0.5%, 1.5% and 5.2% among Asians in rural India, Beijing, Russia and Singapore, respectively. In the population-based studies, older age (per year; OR=1.13), female (OR=2.0), spherical equivalent (SE; per negative diopter; OR=1.7), longer AL (per mm; OR=3.1) and lower education (OR=1.9) were associated with MMD after multivariable adjustment (all p<0.001). Similarly, in the clinic-based/school-based studies, older age (OR=1.07; p<0.001), female (OR=2.1; p<0.001), longer AL (OR=2.1; p<0.001) and lower education (OR=1.7; p=0.005) were associated with MMD after multivariable adjustment. SE had the highest AUC of 0.92, followed by AL (AUC=0.87). The combination of SE, age, education and gender had a marginally higher AUC (0.94).

CONCLUSION

In this pooled analysis of multiple Asian studies, older age, female, lower education, greater myopia severity and longer AL were risk factors of MMD, and myopic SE was the strongest single predictor of MMD.

Prevalence and risk factors of myopia in Han and Yugur older adults in Gansu, China: a cross-sectional study

Few studies have investigated the prevalence of myopia in Northwest China. This cross-sectional study aimed to investigate the prevalence and associated factors of myopia and high myopia in adults aged 40–80 years in the Han and Yugur populations living in Gansu Province, Northwest China. A total of 3,845 participants were included. The overall age- and sex-adjusted prevalence of myopia (spherical equivalent (SE) < −0.5 D), high myopia (SE < −6.0 D) and hyperopia (SE > + 0.5 D) were 16.4%, 0.7% and 26.2% in Yugur participants, respectively, and 34.3%, 5.0% and 19.2% in Han participants, respectively. The prevalence of myopia and high myopia in Han participants was significantly higher than that in Yugur participants (both P < 0.001). Yugur population, birth in rural areas, smoking history and outdoor work were found to be negatively associated with myopia. Higher education level and a family history of myopia were found to be positively associated with myopia in the study population. High myopia was negatively associated with Yugur population, aging, birth in rural areas and was positively associated with a family history of myopia. This study provided valuable information regarding the environmental risk factors of myopia and revealed an ethnic disparity in the prevalence of myopia in Gansu Province, Northwest China.

Risk factors for high myopia: a 22-year follow-up study from childhood to adulthood

PURPOSE

To determine the effect of the definition of high myopia on its prevalence and risk factors for high myopia.

METHODS

A total of 240 myopic schoolchildren (119 boys and 121 girls) at the mean age of 10.9 years (range 8.8-12.8 years) were recruited to a randomized clinical trial of myopia treatment among children from 3rd- and 5th grades of school referred for an eye examination due to poor distant vision and having no previous spectacles. Clinical follow-ups, including refraction with cycloplegia, were conducted annually at 3 years [third follow-up here = clinical follow-up 1, (n = 237)], and thereafter twice at approximately 10-year intervals [clinical follow-ups 2 (n = 179) and 3, (n = 134)]. Additional refraction values between follow-ups 2 and 3 were received from ophthalmologists and opticians' prescriptions and records. The most recent adulthood refraction measure available was taken as the final refraction value for 204 (85%) of the original cohort [mean follow-up time (±standard deviation) 22.1 (±3.9) years]. Parental myopia, time spent on reading and close work, watching TV and outdoor activities were assessed with a questionnaire at the clinical follow-ups. The influence of different definitions of high myopia on its prevalence was analysed. The associations of different factors with high myopia were investigated.

RESULTS

Mean spherical equivalent (SE) at baseline was -1.43 (±0.60) D, ranging from -0.38 D to -3.00 D. At follow-up end, mean SE of the more myopic eye was -5.29 (±1.95) D, ranging from -1.00 D to -11.25 D. High myopia prevalence with the definitions SE < -6.00 D in the right eye and SE ≤ -6.00 D or ≤-5.00 D in either eye was 24%, 32% and 52%, respectively. In this study, high myopia was defined as spherical equivalent (SE) ≤ -6.00 D in either eye. If both parents were myopic, the odds ratio (OR) of having high myopia was 3.9 (95% CI: 1.5-10.4). Younger age at baseline predicted higher prevalence of high myopia; baseline ages between 8.8 and 9.7 and between 11.9 and 12.8 years gave prevalences 65% and 7%. Higher myopia at baseline, higher myopic progression between the first follow-ups and more time spent on reading and close work as compared with time spent outdoors were associated with high myopia.

CONCLUSION

About 32% of the children receiving first spectacles for myopia between ages of 8.8-12.8 years had high myopia (SE ≤ -6.00 D in either eye) in adulthood. Different definitions of high myopia ranging between -5 D and -6 D lead to large differences in prevalence. A generally accepted definition of high myopia is thus needed. Parental myopia, age at baseline, myopic progression during the first post onset year, and more time spent on reading and close work and less on outdoor activities in childhood were associated with adulthood high myopia.

Axial length development in children

AIM

To study ocular axial lengths in pediatric subjects without intraocular pathology.

METHODS

An Institutional Review Board-approved consecutive retrospective chart review of axial lengths measured in pediatric subjects who underwent examination under anesthesia due to positive family history of retinoblastoma or other inherited ocular disease. Only subjects without any intraocular pathology in either eye were included. Subjects were stratified into age groups. An axial length model using a logarithmic regression algorithm was calculated.

RESULTS

Data from 330 eyes of 165 subjects were included in the study. The mean age at the time of examination was 30.62 (SD 18.04)mo. The steepest increase in axial length was present during the first 10mo of life. After 36mo, there was no statistically significant axial length growth.

CONCLUSION

This study presents the biggest series of pediatric axial lengths in healthy eyes. The axial length model developed with these data may assist in the diagnosis and management of a wide variety of pediatric ophthalmic diseases.

Outdoor Jogging and Myopia Progression in School Children From Rural Beijing: The Beijing Children Eye Study

Purpose

To assess the influence of an outdoor program on myopia progression in school children.

Methods

The prospective interventional school-based study included 373 students aged 6 to 7 years (grade 1 or 2) who were examined annually between 2012 and 2016. Between 2012 and 2013, the children in the study group (n = 157) performed a 30-minute jogging exercise every school day, while the children in the control school (n = 216) did not. All children underwent a comprehensive ocular examination, including biometry.

Results

At 1 year after baseline, axial elongation and progression of myopic refractive error were significantly lower in the study group than in the control group. Study group and control group differed in axial elongation only in the subgroup of children nonmyopic at baseline, while axial elongation in the children myopic at baseline did not differ between both groups. At 1 and 2 years after the outdoor program stopped, increase in axial length was significantly larger in the study group. At 4 years after baseline, study group and control group did not differ significantly in total axial elongation and total change in refractive error.

Conclusions

An outdoor program of 30 minutes performed every school day for 1 year temporarily reduced myopia progression in schoolchildren nonmyopic at baseline, with a complete rebound effect after the program ended within the 3 following years.

Translational Relevance

An outdoor program of 30 minutes performed every school day for 1 year temporarily reduced the progression of myopia in schoolchildren nonmyopic at baseline for the period when the program was carried out.

Myopia is associated with education: Results from NHANES 1999-2008

Purpose

Myopia is increasing worldwide and possibly linked to education. In this study, we analyse the association of myopia and education in the U.S. and investigate its age-dependency.

Methods

We conducted a secondary data analysis using the public use files from the cross-sectional study National Health and Nutrition Examination Survey of the period from 1999 to 2008. 19,756 participants aged 20 to 85 years were included with data on education and ophthalmic parameters (distance visual acuity, objective refraction and keratometry). Spherical equivalent, astigmatism, corneal power and corneal astigmatism were evaluated for an association with education using linear regression analysis with adjustment of potential confounders.

Results

Analysis revealed an association between spherical equivalent and educational level in the univariate analysis (P < .001), and in the adjusted model (P < .001). Subjects who attend school to less than 9th grade had a mean spherical equivalent of 0.34 D, subjects with 9-11th grade -0.14 D, subjects that finished high school -0.33 D, subjects with partial college education -0.70 D, subjects that graduated from college or a higher formal education -1.22 D. Subjects that graduated from college or above were -1.47 D more myopic compared to subjects that completed less than 9^th grade school in the adjusted analyses. Astigmatism and corneal curvature was not associated with education.

Conclusions

Myopia is associated with higher education in the U.S. Our analysis shows that corneal curvature does not contribute to this association, therefore axial elongation or lens power are likely to contribute to myopia.

Abnormal resting-state functional network centrality in patients with high myopia: evidence from a voxel-wise degree centrality analysis

AIM

To investigate the functional networks underlying the brain-activity changes of patients with high myopia using the voxel-wise degree centrality (DC) method.

METHODS

In total, 38 patients with high myopia (HM) (17 males and 21 females), whose binocular refractive diopter were -6.00 to -7.00 D, and 38 healthy controls (17 males and 21 females), closely matched in age, sex, and education levels, participated in the study. Spontaneous brain activities were evaluated using the voxel-wise DC method. The receiver operating characteristic curve was measured to distinguish patients with HM from healthy controls. Correlation analysis was used to explore the relationship between the observed mean DC values of the different brain areas and the behavioral performance.

RESULTS

Compared with healthy controls, HM patients had significantly decreased DC values in the right inferior frontal gyrus/insula, right middle frontal gyrus, and right supramarginal/inferior parietal lobule (P<0.05). In contrast, HM patients had significantly increased DC values in the right cerebellum posterior lobe, left precentral gyrus/postcentral gyrus, and right middle cingulate gyrus (P<0.05). However, no relationship was found between the observed mean DC values of the different brain areas and the behavioral performance (P>0.05).

CONCLUSION

HM is associated with abnormalities in many brain regions, which may indicate the neural mechanisms of HM. The altered DC values may be used as a useful biomarker for the brain activity changes in HM patients.

Prevalence and characteristics of peripheral myopic retinopathy in Guangzhou office workers

AIM

To determine the prevalence and characteristics of peripheral myopic retinopathy among a sample of Guangzhou office workers.

METHODS

A cross-sectional study of Guangzhou Chinese office works in different departments and units of the Guangzhou Power Supply Bureau, China, in 2016. Myopic retinopathy was recorded and analyzed with a scanning laser ophthalmoscope and by slit-lamp microscopy combined with a three-mirror contact lens.

RESULTS

In total, 1910 eyes of 955 subjects (508 females and 447 males) aged 21-59y were included; 69.6% of these eyes were myopic. The myopia group had a younger age and worse uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) when compared with hyperopia and emmetropia groups (P<0.001). The axial length (AL) was significantly longer, the spherical equivalent (SE) was more serious, and the optic nerve crescent was significantly larger in subjects with myopia than with hyperopia and emmetropia. Subjects with myopia, and especially high myopia, had the highest frequency of myopic retinal 18 changes (49.4%, P<0.001) [white-without-pressure (43.8%, P<0.001), lattice degeneration (4.5%, P=0.044)] among the three groups. Logistic regression confirmed that any myopia (OR: 3.41, P<0.001) [mild myopia (OR: 1.93, P=0.001), moderate myopia (OR:3.64, P<0.001), and high myopia (OR:10.58, P<0.001)], a greater AL (OR: 1.55, P<0.001) and a much higher SE (OR: 0.77, P<0.001) increased the risk for peripheral retinal changes.

CONCLUSION

Myopia-related retinal changes are positively associated with greater AL, higher SE, and myopia.

Ten-Year Progression of Myopic Maculopathy: The Beijing Eye Study 2001-2011

PURPOSE

To investigate the progression pattern of myopic maculopathy and associated factors in a population-based study.

DESIGN

Population-based longitudinal study.

PARTICIPANTS

The Beijing Eye Study including 4439 participants in 2001 was repeated in 2011, with 2695 individuals (66.4%) being re-examined in 2011.

METHODS

The study participants underwent detailed ophthalmic and general examinations. Using fundus photographs obtained in 2001 and 2011, we assessed the progression of myopic maculopathy in highly myopic eyes with a refractive error ≥-6 diopters in 2001. Myopic maculopathy was differentiated into tessellated fundus (category 1), diffuse chorioretinal atrophy (category 2), patchy chorioretinal atrophy (category 3), and macular atrophy (category 4), with lacquer cracks and choroidal neovascularization as additional plus signs.

MAIN OUTCOME MEASURES

Progression pattern of myopic maculopathy.

RESULTS

Of 110 highly myopic eyes (70 individuals) at baseline, 39 eyes (35.5%) showed progression observed in 15 of 79 eyes (19%) with tessellated fundus at baseline, in 17 of 24 eyes (71%) with diffuse chorioretinal atrophy, in all 6 eyes with patchy chorioretinal atrophy, and the 1 eye with macular atrophy. Lacquer cracks detected in 2 eyes in 2001 developed into a small patchy atrophy (1 eye) or widened during the follow-up (1 eye). Five eyes demonstrated new lacquer cracks. In binary regression analysis, progression of myopic maculopathy was associated with longer axial length (P < 0.001; odds ratio [OR], 7.13; 95% confidence interval [CI], 2.49-20.4), older age (P = 0.001; OR, 1.25; 95% CI, 1.10-1.42), higher prevalence of staphylomas (P = 0.03; OR, 24.3; 95% CI, 2.89-204), smaller parapapillary γ-zone in 2011 (P = 0.01; OR, 0.61; 95% CI, 0.41-0.91), and female gender (P = 0.04; OR, 9.78; 95% CI, 1.06-90.6).

CONCLUSIONS

The 10-year progression rate of myopic maculopathy in this elderly Chinese population was 35.5%, increasing from 15 of 79 eyes (19%) in category 1 of myopic maculopathy at baseline to 17 of 24 eyes (71%) in category 2 and 6 of 6 eyes (100%) in category 3. Risk factors for myopic maculopathy progression were longer axial length, pre-existing staphylomata, smaller parapapillary γ-zone, older age, and female gender.

High myopia in Greater Beijing School Children in 2016

Purpose

To assess prevalence and associated factors of myopia and high myopia in schoolchildren in Greater Beijing.

Methods

The school-based, cross-sectional Greater Beijing School Children Myopia study was carried out in the year 2016 in 54 schools randomly selected from 15 districts in Beijing. Non-cycloplegic auto-refractometry of the right eyes was performed.

Results

The study included 35,745 (99.4%) out of 35,968 eligible pupils with a mean age of 12.6±3.4 years (range 6–18 years). Prevalence of myopia defined as myopic refractive error of ≥-0.50 diopters (D),≥-1D,≥-6D,≥-8D and ≥-10D was 70.9%(95% confidence intervals (CI):70.5,71.4), 60.9% (95%CI:60.4,61.4), 8.6%(95%CI:8.4,8.9), 2.2%(95%CI:2.0,2.4), and 0.3% (95%CI:0.3,0.4), respectively. The frequency of high myopia (≥-6D, ≥-8D, ≥-10D) increased from 1.5% (95%CI:1.0,2.0), 0.4% (95%CI:0.1,0.6) and 0.1% (95%CI:0.00,0.02), respectively in 10-year-olds to 19.4% (95%CI:17.3,21.6), 5.2% (95%CI:4.0,6.4) and 0.9% (95%CI:0.4,1.5), respectively, in 18-year-olds. Mean refractive error in the 18-year-olds was -3.74±2.56D (median:-3.63D;range:-19.6D to + 6.25D). Higher prevalence of high myopia (≥-6D and ≥-8D) was correlated (all P<0.001) with older age (OR:1.18, and 1.15, respectively), female gender (OR: 1.44 and 1.40, respectively), higher body mass index (OR: 1.02 and 1.03, respectively), taller body height (OR: 1.03 and 1.02, respectively), urban region of habitation (OR: 1.26 and 1.33, respectively) and higher school type (OR:1.57 and 2.22, respectively). Prevalence of severe high myopia (≥-10D) was associated only with older age (P<0.001; OR: 1.44; 95%CI: 1.31, 1.59) but not with any education-related parameter such as higher school type (P = 0.48), urban region of habitation (P = 0.07) or female gender (P = 0.37).

Conclusion

In this most recent survey, prevalence of high myopia (≥-6D:19.4%;≥-8D:5.2%;≥-10D:0.9%) in 18-year-old school children was higher than in previous surveys from mainland China. In contrast to minor high myopia and moderate high myopia (defined as myopic refractive error of <-10D), severe high myopia (myopic refractive error ≥-10D) was not strongly correlated with educational parameters.

The epidemics of myopia: Aetiology and prevention

There is an epidemic of myopia in East and Southeast Asia, with the prevalence of myopia in young adults around 80-90%, and an accompanying high prevalence of high myopia in young adults (10-20%). This may foreshadow an increase in low vision and blindness due to pathological myopia. These two epidemics are linked, since the increasingly early onset of myopia, combined with high progression rates, naturally generates an epidemic of high myopia, with high prevalences of "acquired" high myopia appearing around the age of 11-13. The major risk factors identified are intensive education, and limited time outdoors. The localization of the epidemic appears to be due to the high educational pressures and limited time outdoors in the region, rather than to genetically elevated sensitivity to these factors. Causality has been demonstrated in the case of time outdoors through randomized clinical trials in which increased time outdoors in schools has prevented the onset of myopia. In the case of educational pressures, evidence of causality comes from the high prevalence of myopia and high myopia in Jewish boys attending Orthodox schools in Israel compared to their sisters attending religious schools, and boys and girls attending secular schools. Combining increased time outdoors in schools, to slow the onset of myopia, with clinical methods for slowing myopic progression, should lead to the control of this epidemic, which would otherwise pose a major health challenge. Reforms to the organization of school systems to reduce intense early competition for accelerated learning pathways may also be important.

Prevalence of myopic retinopathy in rural Central India

PURPOSE

The aim of this study was to determine the prevalence of myopic retinopathy (MR) in rural Central India.

METHODS

The population-based Central India Eye and Medical Study included 4711 subjects (aged 30+ years). The participants underwent a detailed eye examination, including fundus photography. Myopic retinopathy was defined according to the Pathologic Myopia Study Group.

RESULTS

Readable fundus photographs were available on 4561 (96.8%) subjects (8846 eyes). Myopic retinopathy was present in 15 (0.17 ± 0.04%; 95% confidence interval (CI):0.08%, 0.26%) eyes of 11 (0.24 ± 0.07%; 95%CI: 0.01, 0.04) individuals. Myopic retinopathy occurred only in eyes with an axial length of >26 mm. Eyes with MR had significantly larger optic discs than eyes without MR (3.69 ± 1.22 mm² versus 2.52 ± 0.77 mm² ; p < 0.001). In binary regression analysis, higher prevalence of MR was associated with longer axial length (p < 0.001; odds ratio (OR): 19.6; 95%CI: 4.6, 82.9), higher prevalence of open-angle glaucoma (p = 0.02; OR: 16.1; 95%CI: 1.51, 170), lower best-corrected visual acuity (expressed in logMAR) (=0.03; OR: 0.06; 95%CI: 0.004, 0.75) and female gender (p = 0.002). If level of education was added to the model, educational level was not significantly associated with MR (p = 0.17; OR: 0.53; 95%CI: 0.22, 1.31). If gender was dropped from the model, higher prevalence of MR was associated with lower educational level (p = 0.04; OR: 0.44; 95%CI: 0.20, 0.97).

CONCLUSIONS

Prevalence of MR in rural Central India was low (11/4561 or 0.2%), and correlated with a 16 times higher risk of open-angle glaucoma, after adjusting for axial length and gender. If gender was excluded from the analysis, higher prevalence of MR was associated with lower educational level. This latter finding distinguishes adult MR from today's school children myopia which is strongly associated with higher educational level.

Environmental Factors and Myopia: Paradoxes and Prospects for Prevention

The prevalence of myopia in developed countries in East and Southeast Asia has increased to more than 80% in children completing schooling, whereas that of high myopia has increased to 10%-20%. This poses significant challenges for correction of refractive errors and the management of pathological high myopia. Prevention is therefore an important priority. Myopia is etiologically heterogeneous, with a low level of myopia of clearly genetic origins that appears without exposure to risk factors. The big increases have occurred in school myopia, driven by increasing educational pressures in combination with limited amounts of time spent outdoors. The rise in prevalence of high myopia has an unusual pattern of development, with increases in prevalence first appearing at approximately age 11. This pattern suggests that the increasing prevalence of high myopia is because of progression of myopia in children who became myopic at approximately age 6 or 7 because age-specific progression rates typical of East Asia will take these children to the threshold for high myopia in 5 to 6 years. This high myopia seems to be acquired, having an association with educational parameters, whereas high myopia in previous generations tended to be genetic in origin. Increased time outdoors can counter the effects of increased nearwork and reduce the impact of parental myopia, reducing the onset of myopia, and this approach has been validated in 3 randomized controlled trials. Other proposed risk factors need further work to demonstrate that they are independent and can be modified to reduce the onset of myopia.

Altered spontaneous brain activity pattern in patients with high myopia using amplitude of low-frequency fluctuation: a resting-state fMRI study

OBJECTIVE

Many previous reports have demonstrated significant neural anatomy changes in the brain of high myopic (HM) patients, whereas the spontaneous brain activity changes in the HM patients at rest are not well studied. Our objective was to use amplitude of low-frequency fluctuation (ALFF) method to investigate the changes in spontaneous brain activity in HM patients and their relationships with clinical features.

METHODS

A total of 38 patients with HM (17 males and 21 females) and 38 healthy controls (HCs) (17 males and 21 females) closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was used to assess local features of spontaneous brain activity. The relationship between the mean ALFF signal values in many brain regions and the clinical features in HM patients was calculated by correlation analysis.

RESULTS

Compared with HCs, the HM patients had significantly lower ALFF in the right inferior and middle temporal gyrus, left middle temporal gyrus, left inferior frontal gyrus/putamen, right inferior frontal gyrus/putamen/insula, right middle frontal gyrus, and right inferior parietal lobule and higher ALFF values in the bilateral midcingulate cortex, left postcentral gyrus, and left precuneus/inferior parietal lobule. However, no relationship was found between the mean ALFF signal values of the different areas and the clinical manifestations in HM.

CONCLUSION

The HM patients were affected with brain dysfunction in many regions, which may indicate the presence of neurobiological changes involving deficits in language understanding and attentional control in HM patients.