Impact of Family History of High Myopia on Level and Onset of Myopia

Interventions to increase time spent outdoors for preventing incidence and progression of myopia in children

BACKGROUND

Myopia or nearsightedness is a type of refractive error. It causes people to see near objects clearly but distant objects as blurred. Good vision can be obtained if the refractive error is corrected properly but, where this is not possible, impaired vision will remain. The remaining myopia imposes a considerable personal and societal burden. In addition, the progression of myopia is more likely to be accompanied by other ocular diseases such as cataract, glaucoma and retinal detachment. Myopia has emerged as a significant global public health problem in recent years. The World Health Organization (WHO) reported uncorrected or undercorrected myopia to be a major cause of visual impairment worldwide. From both an individual and social perspective, it is important to prevent the onset of myopia and slow down its progression. Observational studies have shown that children who spend more time outdoors have a lower incidence of myopia. Several other non-Cochrane systematic reviews have focused on the association between increasing children's outdoor activity time and the prevention of myopia. However, none of these systematic reviews were limited to randomised controlled trials (RCTs), as they included all types of study designs, including observational studies and non-RCTs, in addition to RCTs.

OBJECTIVES

To assess the effects of interventions to increase outdoor time on the incidence and progression of myopia in children.

SEARCH METHODS

We searched CENTRAL, MEDLINE Ovid, Embase Ovid, ISRCTN registry, ClinicalTrials.gov, and the WHO ICTRP with no language restrictions. The databases were last searched on 24 June 2022.

SELECTION CRITERIA

We included RCTs and cluster-RCTs in which interventions were performed to increase the outdoor time for children with the aim of preventing the incidence and progression of myopia.

DATA COLLECTION AND ANALYSIS

We employed the standard methods recommended by Cochrane and assessed the certainty of the evidence using GRADE. We considered the following outcome measures: mean change in refractive error from baseline, incidence of myopia, mean change in the axial length from baseline, mean change in unaided distance visual acuity from baseline, quality of life and adverse event.

MAIN RESULTS

We included five RCTs in this review, four of which were cluster-RCTs. The total number of participants was 10,733. The included participants were primary school children, most of whom were in first or second grade (aged six to nine years). Four cluster-RCTs involved school-based interventions to encourage children to spend more time outdoors. The interventions included classroom time outdoors, routine for spending recess outdoors, motivational tools for spending time outdoors, and encouragement through electronic information tools. The intervention groups had less change in refractive errors in the direction of myopia; however, 95% confidence intervals (CIs) included no benefit or both benefit and harm at years one and three, and differences at year two included both clinically important and unimportant benefits (at 1 year: mean difference (MD) 0.08 dioptres (D), 95% CI -0.01 to 0.17; 4 studies, 1656 participants; low-certainty evidence; at 2 years: MD 0.13 D, 95% CI 0.06 to 0.19; 4 studies, 2454 participants; moderate-certainty evidence; at 3 years: MD 0.17 D, 95% CI -0.17 to 0.51; 1 study, 729 participants; low-certainty evidence). Our protocol defined a difference of 0.1 D in the change in refractive error as clinically important. At one year, the difference was less than 0.1 D, but at two and three years it was more than 0.1 D. The incidence of myopia was lower in the intervention groups compared to the control groups, but 95% CIs included no change or clinically unimportant benefits (at 1 year: 7.1% with intervention versus 9.5% with control; risk ratio (RR), 0.82, 95% CI 0.56 to 1.19; 3 studies, 1265 participants; low-certainty evidence; at 2 years: 22.5% with intervention versus 26.7% with control; RR 0.84, 95% CI 0.72 to 0.98; 3 studies, 2104 participants; moderate-certainty evidence; at 3 years: 30.5% with intervention versus 39.8% with control; RR 0.77, 95% CI 0.59 to 1.01; 1 study, 394 participants; moderate-certainty evidence). Our protocol defined a difference of 3% in the incidence of myopia as clinically important. At one year, the difference was 2.4%, but there were clinically important differences between the two groups at two (4.2%) and three years (9.3%). The intervention groups had smaller changes in axial lengths in the direction of myopia than the control groups; however, 95% CIs included no benefit or both benefit and harm at years one and three (at 1 year: MD -0.04 mm, 95% CI -0.09 to 0; 3 studies, 1666 participants; low-certainty evidence; at 2 years: MD -0.04 mm, 95% CI -0.07 to -0.01; 3 studies, 2479 participants; moderate-certainty evidence; at 3 years: MD -0.03 mm, 95% CI -0.13 to 0.07; 1 study, 763 participants; moderate-certainty evidence). No included studies reported changes in unaided distance visual acuity and quality of life. No adverse events were reported.

AUTHORS' CONCLUSIONS

The intervention methods varied from adopting outdoor activities as part of school lessons to providing information and motivation for encouraging outdoor activities. The results of this review suggest that long-term interventions to increase the time spent outdoors may potentially reduce the development of myopia in children. However, although the interventions may also suppress the progression of myopia, the low certainty of evidence makes it difficult to draw conclusions. Further research needs to be accumulated and reviewed.

The Effects of Repeated Low-Level Red-Light Therapy on the Structure and Vasculature of the Choroid and Retina in Children with Premyopia

INTRODUCTION

The purpose of this study was to explore the effects of repeated low-level red-light (RLRL) therapy on the structure and vasculature of the choroid and retina in Chinese children with premyopia.

METHODS

This study was a single-center randomized clinical trial. A total of 94 children with premyopia (- 0.50 D < spherical equivalent [SE] ≤  + 0.75 D) were randomly assigned to either the RLRL therapy or control group. Follow-up visits were planned at 1, 3, 6, 9, and 12 months. Optical coherence biometry was used to measure axial length (AL) and anterior segment parameters. Choroidal thickness (CT), retinal thickness (RT), superficial retinal vascular density (SRVD), deep retinal vascular density (DRVD), choriocapillaris perfusion area (CCPA), and choroidal vessel volume (CVV) were measured by optical coherence tomography angiography, centered on the foveal, parafoveal (ParaF), and perifoveal (PeriF) regions.

RESULTS

The thickening of the choroid was observed across the entire macular region at different time points in the RLRL therapy group. Relative to the baseline measurement, foveal CT significantly increased at the 1-month follow-up with RLRL therapy, with a mean (± standard deviation [SD]) adjusted change of 16.96 ± 19.87 μm. The greatest magnitude of foveal CT changes was observed at the 3-month visit (an increase of 19.58 ± 20.59 μm), with a slight reduction in the extent of foveal CT increase at the 6-month visit (an increase of 15.85 ± 23.77 μm). The second greatest CT increase was observed at the 9-month visit (an increase of 19.57 ± 35.51 μm), after which the extent of CT increase gradually decreased until the end of the study at the 12-month visit (an increase of 11.99 ± 32.66 μm). We also observed a significant increase in CT in the ParaF and PeriF areas in the RLRL group over 12 months. In contrast, CT across the entire macular region in the control group significantly decreased throughout the follow-up visits (all P < 0.05). Regarding the vascular parameters of the choroid, significant increases in CVV were observed primarily in the ParaF and PeriF regions of the choroid in the RLRL group. In comparison, the control group exhibited decreases in CVV throughout the entire area. Furthermore, notable elevations in CCPA were detected in the PeriF area of the choroid in the RLRL group during the 1-month (an increase of 0.40 mm2), 3-month (an increase of 0.25 mm2), and 12-month visits (an increase of 0.42 mm2) (all P < 0.05). In addition, no notable differences were observed between the groups regarding foveal RT and retinal vascular parameters throughout the 12 months (P > 0.05). Notably, RLRL therapy achieved a notable reduction in SE shift by 73.8%, a substantial decrease in AL change by 67.9%, and a significant reduction in myopia incidence by 45.1% within 1 year.

CONCLUSION

Our study demonstrated a significant increase in CT and flow in the RLRL-treated eyes throughout the 12-months of the study. Combined with its reduction in spherical equivalent progression and axial elongation, RLRL could be used as an effective therapy for preventing progression in premyopes.

TRIAL REGISTRATION

ChiCTR2200062028.

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.

Prevalence of Myopia and Its Associated Risk Factors Among Children Attending a Tertiary Hospital in Saudi Arabia

CLINICAL RELEVANCE

This study serves as a tool for optometrists and ophthalmologists to reinforce adherence to several preventive factors, which may decrease the incidence of myopia, and avoidance of risk factors by multiple means including education during hospital visits. It also provides insight into who should be screened and tailored screening programs for children.

BACKGROUND

While studies assessing the prevalence of myopia in Saudi Arabia have contradicting results, only a few studies have evaluated the risk factors of myopia and the effect of using electronic devices on its occurrence. Thus, this study aimed to determine the prevalence of myopia and associated risk factors, among children attending an ophthalmology clinic in King Abdulaziz Medical City, Jeddah, Saudi Arabia.

METHODS

 A cross-sectional study was conducted. A total of 182 patients aged < 14 years were selected using convenient sampling. Direct assessment of the refraction was performed in the clinic, and a questionnaire was completed by the child's parent.

RESULTS

Of 182 patients who met the inclusion criteria, 40.7% had myopia. Myopia was more common in boys (56.8%) than in girls (43.2%), with a median age of 8.7 years. Using multivariate regression analysis, only age (eight years and above) (OR=2.15, CI=1.12-4.12, P= 0.03), and family history of myopia (OR= 5.83, CI= 2.82-12.05, P= 0.001) were significant predictors of myopia in children. Other variables (e.g., sex, and use of laptops, computers, smartphones/tablets, or TV) were not statistically significant.

CONCLUSIONS

This study did not show a statistically significant association between using electronic devices and the onset and progression of myopia among children. Studies with a larger sample size are required to further investigate this association and assess other potential risk factors.

Myopia Progression Among School-Aged Children in the COVID-19 Distance-Learning Era

Objective

To investigate the effect of online learning and other environmental factors on myopia progression during the Coronavirus pandemic (COVID-19).

Methods

A retrospective cohort study from 2018 to 2021. Data from children aged 6-14 were gathered during three visits: pre-pandemic, at the beginning, and during the pandemic. Demographics (hours spent on screens for educational, recreational purposes, outdoors, and type of screen), best-corrected distance visual acuity (BCDVA), uncorrected distance visual acuity (UCDVA), and cycloplegic refraction were gathered.

Results

Of 150 patients, 70 [47%] were boys. The mean age was 11 (2.4) years. Participants mainly used mobile phones (62%) and had insufficient outdoor play (88%). Of the 300 eyes, 221 (74%) showed myopia progression. A significant difference in spherical equivalent (SE) was found between pre-pandemic and post-pandemic periods (-0.29 (0.23) D vs -0.40 (0.11) D; p =0.023). Additionally, UCDVA showed a difference between the initial and 1st follow-up visits (0.57 (0.37) vs 0.64 (0.36), p =0.001), and the first and 2nd follow-up visits (0.64 (0.36) vs 0.70 (0.36), p =0.001). Significant hazard ratio for change in SE in patients with higher age (>9 years), (HR [95% confidence interval (CI)], 0.71 [0.51-0.84]), greater recreational screen usage (HR [95% CI], 1.26 [1.15-1.66]), and insufficient outdoor time (HR [95% CI], 1.45 [1.35-1.67]).

Conclusion

Myopia progression was accelerated during the COVID-19 pandemic. Younger age, prolonged screen use, and insufficient outdoor time contributed to increased myopia progression. However, the type of device used had no significant effect.

Correlation of parental and childhood myopia in children aged 5-16 years in North India

Purpose

The aim of this study was to determine the correlation of parental and childhood myopia among school children aged 5-16 years in North India.

Methods

This study included a total of 1400 children aged 5-16 years in a district in North India. Visual acuity was measured using a Snellen's chart. Children with myopia after retinoscopy were worked up in detail in our institute and a history of parental myopia was taken.

Results

A total of 1400 students studying in class 5-10, aged between 5 and 16 years, were screened. A total of 487 students had myopia. Of the 487 myopes, 220 (45.2%) had parental myopia, of which 115 (30.1%) had myopia in both parents, 64 (19.3%) had mothers with myopia, and 41 (13.3%) had fathers with myopia. The prevalence of paternal (P = 0.001) and maternal (P = 0.002) myopia in myopes compared to parental myopia in emmetropes was found to be highly significant. There was a highly significant statistical correlation between maternal myopia and myopia in the child, when compared to the presence of myopia in both the parents (P = 0.007).

Conclusion

There was a statistically significant correlation between myopia in the parents and children, which was more significant in the mothers of the children.

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.

Impact of the Pressure-Free Yutori Education Program on Myopia in Japan

This study aimed to investigate the influence of educational pressure on myopia. A less-intense school curriculum was introduced nationally in Japan beginning in 2012 based on a pressure-free education policy. In this retrospective observational study, a total of 1025 Japanese medical students of Asahikawa Medical University underwent measurements of the cycloplegic refractive error and axial length (AL), from 2011 to 2020. The spherical equivalent (SE) and AL were correlated significantly with the fiscal year of births (p = 0.004 and p = 0.034, respectively) only during enforcement of the system of high-pressure education. The SE and AL regression rates during the two educational approaches differed significantly (p = 0.004 and p = 0.037, respectively). The prevalence of high myopia was correlated significantly (p < 0.001) only during the system of high-pressure education. The regression of the prevalence rate of high myopia during the two education approaches differed significantly (p = 0.010). The progression rates of myopia and increased prevalence of high myopia were observed only during high-pressure education, suggesting that not only ophthalmologists but also educators and the government should work on together to control the progression of myopia.

Early Age of the First Myopic Spectacle Prescription, as an Indicator of Early Onset of Myopia, Is a Risk Factor for High Myopia in Adulthood

Purpose

The present study investigated the risk factors for high myopia in adulthood, with a focus on the age at which children wore their first spectacles.

Methods

Adults aged between 20 and 45 years were invited to complete a questionnaire about age, sex, current refractive error, high myopia in parents, early onset of myopia presented by the age of the first myopic spectacle prescription, refractive power of the first spectacles, and life habits at different educational stages. The associations between these factors and high myopia in adulthood were then evaluated and analyzed.

Results

In total, 331 participants were enrolled. Their average refractive error was −4.03 diopters, and high myopia was noted in 27.5% of the study participants. Only 3.3% of participants had fathers with high myopia, while 6.0% had mothers with high myopia. The participants received their first myopic spectacle prescription at a mean age of 13.35 years, with a mean refractive error of −1.63 diopters. The significant risk factors for developing high myopia in adult life were earlier age of the first spectacles prescribed (p < 0.001), higher refractive power of the first spectacles (p < 0.001), mother with high myopia (p=0.015), and after-school class attendance in senior high school (p=0.018). Those who wore their first spectacles at <9 years of age were more predisposed to high myopia than those who did so at ≧13 years, with an odds ratio of 24.9.

Conclusion

The present study shows that earlier onset of myopia, which is presented by the age of the first myopic spectacle prescription, higher myopic refraction of the first spectacles, mothers with high myopia, and after-school class attendance in senior high school are risk factors for high myopia in adulthood. It suggests that delaying the onset of myopia in children is important for the prevention of high myopia in later life.

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.

Progression of myopic maculopathy in a Caucasian cohort of highly myopic patients with long follow-up: a multistate analysis

PURPOSE

This study aims to determine the probability of progression of myopic maculopathy according to age.

METHODS

This is a longitudinal observational study of single-center retrospective cohort of Caucasian patients formed by 212 consecutive adults with high myopia. Main outcome measures were age, visual acuity (VA), refractive error (RE), follow-up time, and the macular status assessed at least 5 years apart according to the Meta-Analysis of Pathologic Myopia Study Group. The progression rate was calculated based on per 1000 eyes/year. Multistate models were fitted to identify the predictive factors and to calculate the most probable age of progression onset using the Aalen-Johansen estimator.

RESULTS

We studied 220 eyes of 122 Caucasian patients. Mean age was 48.18 ± 14.1, mean follow-up 12.73 ± 5.81 years. One-hundred and fifty-two (69.1%) eyes progressed of category, and 96 (44%) worsened a mean of 0.3 logMAR units during follow-up. The progression rate was 32.21/1000 eyes/year. The probability of progressing increased with age; it was higher in women if there was a family history of myopia, worse VA, higher RE, or wide macular staphyloma. The probability of progressing from category 1 was > 0.6 after 70 years of age; from category 2, it was 0.7 after 70 years; and 0.5 from category 3 after 75 years. If choroidal neovascularization (CNV) appeared, this probability exceeded 0.7 between ages 45 and 55 for all categories.

CONCLUSION

The progression rate is lower than in a Japanese series. The vision worsened with disease progression, and the probability of both happening increased after the age of 70-75. If CNV appears, the risk of progression is very high at the age of 45-55.

Pathogenesis and Prevention of Worsening Axial Elongation in Pathological Myopia

PURPOSE

This review discusses the etiology and pathogenesis of myopia, prevention of disease progression and worsening axial elongation, and emerging myopia treatment modalities.

INTRODUCTION

Pediatric myopia is a public health concern that impacts young children worldwide and is associated with numerous future ocular diseases such as cataract, glaucoma, retinal detachment and other chorioretinal abnormalities. While the exact mechanism of myopia of the human eye remains obscure, several studies have reported on the role of environmental and genetic factors in the disease development.

METHODS

A review of literature was conducted. PubMed and Medline were searched for combinations and derivatives of the keywords including, but not limited to, "pediatric myopia", "axial elongation", "scleral remodeling" or "atropine." The PubMed and Medline database search were performed for randomized control trials, systematic reviews and meta-analyses using the same keyword combinations.

RESULTS

Studies have reported that detection of genetic correlations and modification of environmental influences may have a significant impact in myopia progression, axial elongation and future myopic ocular complications. The conventional pharmacotherapy of pediatric myopia addresses the improvement in visual acuity and prevention of amblyopia but does not affect axial elongation or myopia progression. Several studies have published varying treatments, including optical, pharmacological and surgical management, which show great promise for a more precise control of myopia and preservation of ocular health.

DISCUSSION

Understanding the role of factors influencing the onset and progression of pediatric myopia will facilitate the development of successful treatments, reduction of disease burden, arrest of progression and improvement in future of the management of myopia.

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

BACKGROUND

To evaluate the prevalence and risk factors associated with myopia and high myopia in children in South Korea.

METHODS

A total of 983 children 5-18 years of age who participated in the Korean National Health and Nutrition Examination Survey 2016-2017 (KNHANES VII), a nationwide population-based cross-sectional study, were evaluated. Myopia and high myopia were defined as a spherical equivalent (SE) ≤ - 0.5 diopters (D) and SE ≤ --6.0 D. The association between refractive errors and potential risk factors for myopia was analyzed.

RESULTS

The prevalence of myopia and high myopia was 65.4 and 6.9%, respectively. Older age and parental myopia were significantly associated with both myopia and high myopia, while higher body mass index (BMI) was associated with high myopia only. Although the proportion of subjects who spent more time on near work activities (≥4 h/day) was sequentially increased with increased refractive error, this tendency was not statistically significant by multivariable logistic regression.

CONCLUSIONS

Korean children had a high prevalence of myopia and high myopia. In this age group, the risk of myopia increased with aging and parental myopia. Higher BMI may be associated with high myopia.

Efficacy and Safety of 1% Atropine on Retardation of Moderate Myopia Progression in Chinese School Children

Background: To evaluate the long-term efficacy and safety of topical 1% atropine for retarding moderate myopia. Methods: A randomized, controlled study evaluating atropine and placebo in 660 Chinese children. Patients received drops q1month for 24 months, then q2month for 12 months, followed by no drops for 12 months. Spherical equivalent, axial length, intraocular pressure and atropine-related side effects were examined at 6, 12, 24, 36 and 48 months for all children. Results: Spherical equivalent, myopic progression, axial length augmentation, and progression rate were significantly reduced in the atropine group than those in the placebo group (all P<0.05), indicating that 1% atropine effectively retarded myopia. Moreover, myopic rebound and adverse effects of 1% atropine were eliminated by gradual withdrawal and elimination of 1% atropine. Furthermore, pupil size, near visual acuity, and amplitude of accommodation returned to pretreatment levels after withdrawal of atropine. Conclusion: Topical 1% atropine periodically and alternatively in phase I with gradual reduction in phase II and final withdrawal in phase III may effectively improve atropine efficacy, retard moderate myopia, reduce atropine side effects, minimize myopic rebound, and increase compliance of children simultaneously.

Role of Parental Refractive Status in Myopia Progression: 12-Year Annual Observation From the Guangzhou Twin Eye Study

Purpose

We investigate the impact of parental myopia on spherical equivalent (SE) progression and axial length (AL) elongation.

Methods

Children and their parents were invited for annual examinations from 2006 (baseline). Cycloplegic autorefraction and AL were measured at each visit. Parental refractive status was determined using refraction data from their baseline visit. Children were classified into five groups: no myopic parents (non-non), only one moderately myopic parent (non-moderate), only one highly myopic parent (non-high), two moderately myopic parents (moderate-moderate), and one moderately myopic or more severe and one highly myopic parent (moderate-high/high-high). The relationship between progression of SE and AL with parental refractive status was estimated by linear mixed-effects models. Data from 2006 to 2017 were analyzed in the current study.

Results

A total of 1831 children were enrolled (mean age, 11 ± 2.7 years; mean standard error, -0.49 ± 2.16 diopters [D] at baseline. Myopia progressed faster for children with parental myopia (non-non group as reference, all P < 0.05), while AL elongation mirrored the change in SE (all P < 0.001 except for non-mod group P = 0.12). As for the age-specific change in SE and AL, children in the mod-high/high-high group presented with the fastest progression. Children with highly myopic parents were at higher risks of being highly myopic during adulthood (odds ratio = 13.98 and 25.71 for non-high and mod-high/high-high groups; both P < 0.001).

Conclusions

SE progresses and AL elongates at a faster rate at an earlier age in children with parental myopia. Children with highly-myopic parents have higher risks of being highly myopic during adulthood.

IMI - Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report

Myopia has been predicted to affect approximately 50% of the world's population based on trending myopia prevalence figures. Critical to minimizing the associated adverse visual consequences of complicating ocular pathologies are interventions to prevent or delay the onset of myopia, slow its progression, and to address the problem of mechanical instability of highly myopic eyes. Although treatment approaches are growing in number, evidence of treatment efficacy is variable. This article reviews research behind such interventions under four categories: optical, pharmacological, environmental (behavioral), and surgical. In summarizing the evidence of efficacy, results from randomized controlled trials have been given most weight, although such data are very limited for some treatments. The overall conclusion of this review is that there are multiple avenues for intervention worthy of exploration in all categories, although in the case of optical, pharmacological, and behavioral interventions for preventing or slowing progression of myopia, treatment efficacy at an individual level appears quite variable, with no one treatment being 100% effective in all patients. Further research is critical to understanding the factors underlying such variability and underlying mechanisms, to guide recommendations for combined treatments. There is also room for research into novel treatment options.

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.

Genome-wide DNA hypermethylation and homocysteine increase a risk for myopia

AIM

To test for the association between genome-wide methylation and myopia in human and mice.

METHODS

Long interspersed nucleotide element 1 (LINE-1) methylation levels were used to surrogate genome-wide methylation level. We first tested for the association between high myopia (<-6 D) and LINE-1 methylation in leukocytes in 220 cases and 220 control subjects. Secondly, we validated the results of LINE-1 methylation in eyes from the form deprivation myopia (FDM) mice. Furthermore, we calculated the correlation of LINE-1 methylation levels between leukocyte DNA and ocular DNA in the mice. We also tested whether dopamine can alter LINE-1 methylation levels.

RESULTS

The LINE-1 methylation level was significantly higher in the myopic human subjects than controls. The upper and middle tertiles of the methylation levels increased an approximately 2-fold (P≤0.002) risk for myopia than the lower tertile. Similarly, FDM mice had high LINE-1 methylation levels in the leukocyte, retina and sclera, and furthermore the methylation levels detected from these three tissues were significantly correlated. Immunohistochemical staining revealed higher levels of homocysteine and methionine in the rodent myopic eyes than normal eyes. Dopamine treatment to the cells reduced both LINE-1 methylation and DNA methyltransferase levels.

CONCLUSION

LINE-1 hypermethylation may be associated with high myopia in human and mice. Homocysteine and methionine are accumulated in myopic eyes, which may provide excess methyl group for genome-wide methylation.

The high prevalence of myopia in Korean children with influence of parental refractive errors: The 2008-2012 Korean National Health and Nutrition Examination Survey

The present study was conducted to investigate the effect of parental refractive errors on myopic children in Korean families using a nationally representative survey. We used the ophthalmologic examination dataset of the Korean National Health and Nutrition Examination Surveys IV and V, a nationwide population-based cross-sectional study using a complex, stratified, multistage, probability cluster survey, which were performed from 2008–2012. We included 3,862 children from 5–18 years of age from 2,344 families without any ocular trauma, surgical history, or cataract affecting refractive errors. The generalized estimating equation was conducted to assess the association of refractive errors among children and their parents. Among 3,862 children, 2,495 had myopia, which was 64.6% prevalence. There were 208 children with high myopia (5.4%). The prevalence rate ratio (PRR) for pediatric myopia and high myopia with myopic parents was 1.34 (95% confidence intervals [CI] 1.24–1.45) and 3.11 (95% CI 1.93–5.01), respectively. The PRR of myopia and high myopia in children significantly increased to 1.37 (95% CI 1.04–1.81) and 11.41 (95% CI 6.24–20.88), as the degree of parental myopia increased (P < 0.001, respectively). Children with two myopic parents were more myopic than those with only one myopic parent (P < 0.001, respectively). In addition to parental myopia, the age of the child and household income were also significant risk factors for all degrees of pediatric myopia in a family (P ≤ 0.005, respectively). In conclusion, Korean children showed high prevalence of myopia. Children with myopic parents showed a significantly greater risk for myopia and high myopia.

The diluted atropine for inhibition of myopia progression in Korean children

AIM

To evaluate the efficacy and safety of three different concentrations of diluted atropine for the control of myopia in Korean children, and to assess the risk factors associated with rapid myopia progression.

METHODS

A total of 285 children, with refractive errors within the range of -6 diopters (D) between 5 and 14 years of age were included. After using 0.01%, or 0.025%, or 0.05% atropine, for about 1y, changes in refraction, axial lengths and frequency of adverse events were analyzed. Logistic regression analyses were performed to evaluate the risk factors associated with rapid myopia progression.

RESULTS

The changes in the mean spherical equivalent values were -0.134 D/mo in the before atropine group, -0.070 D/mo in the 0.01% atropine group, -0.047 D/mo in the 0.025% atropine group, and -0.019 D/mo in the 0.05% atropine group, with significant differences between the groups (P<0.001). The axial elongation was 0.046 mm/mo, 0.037 mm/mo, 0.025 mm/mo, and 0.019 mm/mo respectively, with significant differences between the groups (P=0.003). The incidence of photophobia and near vision difficulty was not different among the three atropine groups (P=0.425 and P=0.356, respectively). Multivariate logistic regression analyses showed that only highly myopic parents were a significant predictive factor of rapid myopia progression in Korean children (odds ratio, 8.155; 95% confidence interval, 3.626-18.342; P<0.001).

CONCLUSION

Treatment with 0.01%, 0.025% and 0.05% atropine solution inhibits myopia progression in Korean children in a dose-dependent manner. Children with highly myopic parents preferentially shows a rapid myopia progression rate.

The visual status of adolescents in Riyadh, Saudi Arabia: a population study

Purpose

The visual status of adolescents in Saudi Arabia (SA) has not been well reported. To date, the prevalence and types of refractive errors (REs), amblyopia, strabismus, and correctable visual impairments have not been quantified. The aim of the study was to investigate the visual status in adolescents in Riyadh, SA.

Methods

This study was based on a population cross-sectional and random cluster design. After design and the sample calculations, 1,007 participants, 12–20 years of age, were screened during the study. Nine participants were excluded due to ocular disorders. The participants were assessed for REs, distance visual acuity logarithm of the minimum angle of resolution, contrast sensitivity, stereoacuity, pinhole test findings, and cover–uncover test findings.

Results

The results showed that 55.5% of the participants had some form of REs, while correctable visual impairment was found in one-fifth of the screened participants. Myopia was the dominant type (53.3%, ranged from −0.50 DS to −14.00 DS), whereas hyperopia was found in 2.2% (+2.00 DS to +5.50 DS) and astigmatism was present in 15% (−0.75 DC to −5.25 DC). Only 43% of the participants had corrected REs; however, the noncompliance for spectacle use was 20.25%.

Conclusion

This study was the first attempt to investigate the visual status in adolescents in SA. It provided estimations of the REs, amblyopia, and strabismus. The high prevalence of REs emphasizes the need to identify the best proactive strategies to detect and manage REs to reduce the incidence of visual impairment in SA. Increasing awareness about eye health and employing efficient screening programs could help to address the need for REs corrections.

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.

Refractive error and vision correction in a general sports-playing population

PURPOSE

To evaluate, in an amateur sports-playing population, the prevalence of refractive error, the type of vision correction used during sport and attitudes toward different kinds of vision correction used in various types of sports.

METHOD

A questionnaire was used for people engaging in sport and data was collected from sport centres, gyms and universities that focused on the motor sciences.

RESULTS

One thousand, five hundred and seventy-three questionnaires were collected (mean age 26.5 ± 12.9 years; 63.5 per cent male). Nearly all (93.8 per cent) subjects stated that their vision had been checked at least once. Fifty-three subjects (3.4 per cent) had undergone refractive surgery. Of the remainder who did not have refractive surgery (n = 1,519), 580 (38.2 per cent) reported a defect of vision, 474 (31.2 per cent) were myopic, 63 (4.1 per cent) hyperopic and 241 (15.9 per cent) astigmatic. Logistic regression analysis showed that the best predictors for myopia prevalence were gender (p < 0.001) and location of sport practice (p < 0.001). Sports that present higher prevalence of outdoor activity have lower prevalence of myopia. Contact lens penetration over the study sample was 18.7 per cent. Contact lenses were the favourite system of correction among people interviewed compared to spectacles and refractive surgery (p < 0.001).

CONCLUSIONS

This study showed that sport was not associated with different levels of myopia prevalence in the adult population. However, subjects engaging in outdoor sports had lower rates of myopia prevalence. Penetration of contact lens use in sport was four times higher than the overall adult population. Contact lenses were the preferred system of correction in sports compared to spectacles or refractive surgery, but this preference was affected by the type of sport practised and by the age and level of sports activity for which the preference was required.

Prevalence and risk factors for myopia in older adult east Chinese population

BACKGROUND

To determine the prevalence and associated factors for myopia and high myopia among older population in a rural community in Eastern China.

METHODS

A community-based, cross-sectional survey was conducted in the Weitang town located in Suzhou, an urban metropolis in East China. A total of 5613 Chinese residents aged 60 years and older were invited to complete a questionnaire and participated in a detailed eye examination,including measurements of visual acuity and refractive error using autorefraction and subjective refraction. Myopia and high myopia was defined as SE < -0.5 diopters (D) and < -5.0 D, respectively.

RESULTS

Among the 5613 participating individuals, 4795 (85.4%) complete refraction data of phakic right eye was included for analysis. The age-adjusted prevalence was 21.1% (95% confidence interval [CI], 19.9-22.2) for myopia and 2.5% (95% CI, 2.1-2.9) for high myopia. The prevalence of myopia tended to increase significantly with age(p < 0.001),and women had a higher rate of myopia than men (p < 0.001). According to multivariate logistic regression analysis, adults who were older (odds ration[OR]:1.05; 95% CI:1.04-1.07), spent more time for sleeping at night (OR:1.12;95% CI: 1.06-1.18),or had cataract (OR:1.60;95% CI:1.36-1.88) and family history of myopia (OR:1.47;95% CI:1.23-1.77), are more susceptible to myopia (p < 0.001). People who had older age, family history, cataract and specially longer night-time sleep duration, would have a higher risk of myopia.

CONCLUSION

Myopia and high myopia among rural old adult population in Eastern China presents common. The current literature unanticipated suggests that there was a positive significant association between prevalence of myopia and night-time sleep duration among adult. Our data provide some evidence of this relationship and highlight the need for larger studies to further investigate this relationship longitudinally and explore mechanism therein.

Atropine 0.5% eyedrops for the treatment of children with low myopia: A randomized controlled trial

BACKGROUND

This study aimed to assess the efficacy and safety of atropine 0.5% eyedrops (ATE) for the treatment of children with low myopia (LM).

METHODS

In this study, a total of 126 children with LM were randomly divided into an intervention group (administered 0.5% ATE) and a control group (administered a placebo), with 63 children in each group. The outcome measurements were changes in the spherical equivalent (SE), and axial length (AL), as well as adverse events (AEs).

RESULTS

Compared with placebo, administration of 0.5% ATE led to less progression in LM, as measured by SE, and less increase in AL (P < .01). In addition, no serious AEs occurred in both the groups.

CONCLUSION

About 0.5% ATE was efficacious and safe for controlling myopia in children with LM.

Association of IGF1 polymorphism rs6214 with high myopia: A systematic review and meta-analysis

PURPOSE

To conduct a comprehensive evaluation of the association of Insulin-like growth factor 1 (IGF1) polymorphism rs6214 with high myopia through a systematic review and meta-analysis of candidate genetic association study.

METHODS

All case-control association studies on IGF1 and high myopia reported up to 15 June 2016 in PubMed, Embase, Web of Science, and the Chinese Biomedical Database were retrieved. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for single-nucleotide polymorphism (SNP) using fixed and random effects models according to between study heterogeneity. Publication bias analyses were conducted using Begg's test.

RESULTS

A total of eight studies from published articles were included in our analysis. The meta-analyses for IGF1 rs6214, composed of 4242 high myopia patients and 4430 controls, showed low heterogeneity for the included populations in all the genetic models, except that of the allelic genetic model in the pooled populations. The analyses of all the genetic models in Chinese, Japanese, and overall pooled populations did not identify any significant association between high myopia and IGF1 rs6214.

CONCLUSIONS

This meta-analysis showed there was no association detected between IGF1 rs6214 and high myopia. Given the limited sample size, further investigations including more ethnic groups are required to validate the association.

Epidemiology of Myopia

Myopia is not a simple refractive error, but an eyesight-threatening disease. There is a high prevalence of myopia, 80% to 90%, in young adults in East Asia; myopia has become the leading cause of blindness in this area. As the myopic population increases globally, the severity of its impact is predicted. Approximately one fifth of the myopic population has high myopia (≥-6 diopters), which results in irreversible vision loss such as retinal detachment, choroidal neovascularization, cataracts, glaucoma, and macular atrophy. The increasing prevalence of school myopia in the past few decades may be a result of gene-environment interactions. However, earlier school myopia onset would accompany faster myopia progression and greater risk of high myopia later in life. Recently, there have been effective interventions to delay the onset of myopia, such as outdoor activity and decreasing the duration of near work. Hyperopia (≤0.5 diopters) is a predictor of myopia. Pharmacological agents and optic interventions such as low-concentration atropine and orthokeratology may slow progression in myopic children. Novel surgeries and anti-vascular endothelial growth factor drugs could deal with some myopic complications. From available evidence, the prevention, control, and treatment of myopia seem to be promising. However, to reduce the impact of myopia in future decades, more work and effort are still needed, including that by governments and intercountry eye health organizations.

Genetic association of COL1A1 polymorphisms with high myopia in Asian population: a Meta-analysis

AIM

To comprehensively evaluate the potential association of COL1A1 polymorphisms with high myopia by a systematic review and Meta-analysis.

METHODS

All association studies on COL1A1 and high myopia reported up to June 10, 2014 in PubMed, Embase, Web of Science, and the Chinese Biomedical Database were retrieved. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were analyzed for single-nucleotide polymorphisms (SNPs) using fixed- and random- effects models according to between-study heterogeneity. Publication bias analyses were conducted by Egger's test.

RESULTS

A total of four studies from reported papers were included in this analysis. The Meta-analyses for COL1A1 rs2075555, composed of 2304 high myopia patients and 2272 controls, failed to detect any significant association with high myopia. A total of 971 cases and 649 controls were tested for COL1A1 rs2269336. The association of COL1A1 rs2269336 with high myopia was observed in recessive model (CC vs CG+GG, P=0.03) and in heterozygous model (CG vs GG, P=0.04), but not in other models.

CONCLUSION

This Meta-analysis shows that COL1A1 rs2269336 (CC vs CG+GG) affects individual susceptibility to high myopia, whereas there is no association detected between SNPs rs2075555 and high myopia. Given the limited sample size, further investigations including more ethnic groups are required to validate the association.

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

Purpose

Since high myopia in the younger generation may differ etiologically from high myopia in older generations, we examined whether education-related parameters differ between high myopia in today´s school children and high pathological myopia in today´s elderly generation.

Methods

The investigation included the adult populations of the population-based Beijing Eye Study (BES) (3468 adults;mean age:64.6±9.8years;range:50–93years) and Central India Eye and Medical Study (CIEMS) (4711 adults;age:49.±13.2years;range:30–100years), and the children and teenager populations of the Shandong Children Eye Study (SCES) (6026 children;age:9.7±3.3years;range:4–18years;cycloplegic refractometry), Gobi Desert Children Eye Study (1565;age:11.9±3.5years;range:6–21 years;cycloplegic refractometry), Beijing Pediatric Eye Study (681 children;age:7.7±1.6years;range:5–13 years;non-cycloplegic refractometry,calculation of axial length to corneal curvature radius ratio), Beijing Children Eye Study (15066 children;age:13.2±3.4years;range:7–18years;non-cycloplegic refractometry), Beijing High School Teenager Eye Study (4677 children;age:16.9±0.7years;range:16–18years;non-cycloplegic refractometry).

Results

In the BES and CIEMS, educational level did not differ significantly between, or was significantly lower in the highly myopic group (myopic refractive error ≥6 diopters) than in the non-highly myopic group. In all non-adult study populations, higher prevalence of high myopia was significantly associated with higher degree of education related parameters such as attendance of high-level schools, and more time spent for indoors near work versus time spent outdoors.

Conclusions

Comparing associations of old or genetic high myopia in adults with new or acquired high myopia in school children revealed that education-related parameters did not show a clear association with old or genetic high myopia, while in contrast, new high myopia showed strong associations with education. It confirms previous studies that the two forms of high myopia not only differed in age of onset, but also in associations with education as well. The data support the notion of two types of high myopia. Future studies may assess whether the risk of pathologic myopic maculopathy and high myopia associated open-angle glaucoma differs between both types of high myopia.

Study of association of PAX6 polymorphisms with susceptibility to high myopia in a Japanese population

PURPOSE

Many studies have investigated the relationship of paired box 6 (PAX6) gene polymorphisms with the risk of high myopia, but the results across studies remain inconsistent and ambiguous. In the present work, we investigated whether PAX6 polymorphisms are associated with high myopia in a Japanese population.

METHODS

A total of 1,585 Japanese patients with high myopia (spherical equivalent [SE] <-9.00 diopters [D]) and 1,011 Japanese healthy controls (SE≥-1.00 D) were recruited. To compare genotype frequencies between cases and controls, we genotyped five single nucleotide polymorphisms in the PAX6 gene that are reportedly associated with high/extreme myopia: rs662702, rs3026393, rs644242, rs3026390, and rs667773.

RESULTS

For rs662702, rs644242, and rs667773, odds ratios (ORs) for their risk alleles tended to increase with the progression of SE and axial length in the additive and recessive models. Of these, rs644242 had the highest OR (2.56) in patients with SE<-15 D in both eyes in the recessive model. On the other hand, for rs3026393 and rs3026390, the ORs for their risk alleles tended to increase according to the progression of SE and axial length in the dominant model. Of the two, rs3026393 had the highest OR (2.32) in patients with SE<-15 D in both eyes in the dominant model. However, no significant associations were identified in this study.

CONCLUSION

We found that these PAX6 single nucleotide polymorphisms were associated with an increased risk of extreme myopia. Although the results, which are in agreement with some previous studies, did not reach statistical significance, PAX6 single nucleotide polymorphisms may be important risk factors for the development of extreme myopia. Further genetic studies with larger sample sizes and taking into account the degree of myopia are needed to clarify the contribution of PAX6 variants in myopia development.

The Association between Near Work Activities and Myopia in Children-A Systematic Review and Meta-Analysis

Myopia has a multifactorial etiology, although environmental factors are predominant in determining its current patterns. Currently, associations between near work activities and myopia have not been consistently observed. Therefore, we performed a systematic review to quantify the effect of near work activities on myopia in children. Relevant articles published between 1989 and 2014 were identified in MEDLINE, Embase, and the Cochrane Library, and the citation lists were reviewed. Twelve cohort studies and 15 cross-sectional studies were included (25,025 children aged between 6 and 18 years). The I² statistic was used to assess heterogeneity. Study-level data were pooled using a random-effects model or a fixed-effects model (when less than 5 studies were included). We found that more time spent on near work activities was associated with higher odds of myopia (odds ratio [OR] = 1.14; 95% confidence interval [CI] = 1.08–1.20) and that the odds of myopia increased by 2% (OR:1.02; 95% CI = 1.01–1.03) for every one diopter-hour (hr) more of near work per week. Therefore, the development of a strategy to reduce the impact of near work on myopia would be important for preventing myopia in children.

Therapeutic effect of atropine 1% in children with low myopia

PURPOSE

To evaluate the efficacy of topical atropine 1% in promoting unaided visual acuity, reducing myopia, and slowing the progression of ocular axial elongation in Chinese children with low myopia.

METHODS

Children with low myopia were randomly assigned to one of two groups, receiving either atropine 1% (treatment group) or placebo eyedrops (control group) once nightly for 1 year. After instillation of 3 drops of cyclopentolate 1%, unaided visual acuity, cycloplegic refraction, and ocular axial length were tested and recorded at baseline (2 weeks after atropine or vehicle eyedrops), 3 months, 6 months, 9 months, and 1 year.

RESULTS

A total of 132 children 7-12 years of age with a refractive error of spherical equivalent -0.50 D to -2.00 were included. After 1 year, the mean unaided visual acuity in the treatment group was 0.31 ± 0.16 logMAR; in the control group, 0.66 ± 0.15 logMAR, (P < 0.0001). After treatment for 1 year, there was a decrease of 0.32 ± 0.22 D from baseline in the treatment group and an increase of -0.85 ± 0.31 D in the control group (P < 0.0001). The axial elongation in the treatment group was -0.03 ± 0.07 mm; in the control group, 0.32 ± 0.15 mm (P < 0.0001).

CONCLUSIONS

In this study cohort, topical atropine1% reduced the degree of low myopia and slowed the progression of ocular axial elongation in children.

Effect of outdoor activity on myopia onset and progression in school-aged children in northeast China: the Sujiatun Eye Care Study

Background

Due to its high prevalence and associated sight-threatening pathologies, myopia has emerged as a major health issue in East Asia. The purpose was to test the impact on myopia development of a school-based intervention program aimed at increasing the time student spent outdoors.

Methods

A total of 3051 students of two primary (grades 1-5, aged 6-11) and two junior high schools (grades 7-8, aged 12-14) in both urban and rural Northeast China were enrolled. The intervention group (n = 1735) unlike the control group (n = 1316) was allowed two additional 20-min recess programs outside the classroom. A detailed questionnaire was administered to parents and children. Uncorrected visual acuity (UCVA) was measured using an E Standard Logarithm Vision Acuity Chart (GB11533-2011) at baseline, 6-month and 1-year intervals. A random subsample (n = 391) participated in the clinic visits and underwent cycloplegia at the beginning and after 1 year.

Results

The mean UCVA for the entire intervention group was significantly better than the entire control group after 1 year (P < 0.001). In the subgroup study, new onset of myopia and changes in refractive error towards myopia were direction during the study period was significantly lower in the intervention group than in the control group (3.70 % vs. 8.50 %, P = 0.048; -0.10 ± 0.65 D/year vs. -0.27 ± 0.52 D/year, P = 0.005). Changes in axial length and IOP were also significantly lower following the intervention group (0.16 ± 0.30 mm/year vs. 0.21 ± 0.21 mm/year, P = 0.034; -0.05 ± 2.78 mmHg/year vs. 0.67 ± 2.21 mmHg/year, P = 0.006).

Conclusions

Increasing outdoor activities prevented myopia onset and development, as well as axial growth and elevated IOP in children.

Trial registration

Current controlled trials NCT02271373.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-015-0052-9) contains supplementary material, which is available to authorized users.

Association between parental myopia and the risk of myopia in a child

The association between parental myopia and a child's risk of developing the condition is not well understood. Therefore, the present study conducted a meta-analysis of the results of observational studies in order to investigate the association between myopia in parents and their child's risk of developing the condition. The current study systematically examined the databases MEDLINE, Embase and Ovid for relevant studies. Two reviewers independently evaluated the data and extracted the odds ratios (ORs) and 95% confidence intervals (CIs) from the suitable studies. Heterogeneity, publication bias and subgroup analyses were performed. The present meta-analysis included 31,677 participants from 16 studies with 8,393 cases of myopia (six prospective cohort, eight cross-sectional and two case-control studies). The OR of giving birth to a child with myopia, according to the prospective cohort, cross-sectional and case-control studies, was 1.53 (95% CI, 1.21-1.85), 1.96 (95% CI, 1.53-2.39), and 2.13 (95% CI, 1.79-2.46), respectively, when one parent had myopia, and 2.10 (95% CI, 1.42-2.77), 2.96 (95% CI, 2.21-3.71), and 2.13 (95% CI, 1.79-2.46), respectively, when two parents had myopia. The current study identified a significant positive association between parental myopia and a child's risk of developing myopia. Children of two parents with myopia had a higher risk of developing myopia compared to those with one myopic parent.

Evaluating the association between pathological myopia and SNPs in RASGRF1. ACTC1 and GJD2 genes at chromosome 15q14 and 15q25 in a Chinese population

BACKGROUND

This study investigated the association of the 27 SNPs located in RASGRF1. GJD2, and ACTC1 genes with pathological myopia in a Chinese Han population.

METHODS

Myopia patients were stratified according to whether they did (n = 274) or did not (n = 131) have myopic macular degeneration (MMD). The SNPbrowser software was used to identify specific SNPs for analysis and minimal allele frequency of >20%, and a pairwise r(2) < 0.85 were genotyped using MALDI-TOF mass spectrometry.

RESULTS

Before controlling for false discovery rate, the frequency of the rs1867315 C/C genotype compared with healthy controls was lower in the myopia group (p = 0.006) and in myopia patients without macular degeneration (p = 0.019). The frequency of the rs670957A/A genotype was also lower in patients without MMD compared with controls (p = 0.045). For rs2070664, the frequency of the A allele was higher in the patients with MMD compared to those without MMD (p = 0.032). After controlling for a false discovery rate of 5%, there was no significant difference in genotype and allele frequencies between these groups.

CONCLUSION

In this study, there was no association of the analyzed SNPs located in RASGRF1. GJD2, and ACTC1 with pathological myopia, suggesting that SNPs included in our study have no or a limited role in causing pathologic myopia in this Chinese Han population.

Clinical prediction of the need for interventions for the control of myopia

The prevalence of myopia is increasing in Western populations but in East Asian countries, it is increasing to epidemic levels, where there are also markedly increased rates of progression to pathological myopia. Measures to more effectively control the development and progression of myopia are urgently needed. Notwithstanding a large volume of research, especially regarding the different mechanisms for the development of myopia and the efficacy of particular methods of intervention, there is still a great need and scope for improvements in clinical efforts to prevent and/or control myopic progression. Too often clinical efforts may involve only one method of intervention; however, the heterogenous nature of myopia suggests that clinical intervention may be more successful when interventions are employed in combination. The decision to prescribe interventions for the control of myopia in children, especially prior to onset, may be better framed by a comprehensive estimation of the degree of risk for the development and/or progression of myopia. For example, rather than ascribing equal weight to any degree of parental myopia, more accurate estimates may be obtained, if risk is judged to increase with the degree of parental myopia and the extent of any associated degenerative pathology. Risk estimates may be limited to broad mild, moderate and severe classifications due to lack of accurate weighting of risk factors. Nevertheless, comprehensive assessment of risk factors appears likely to better inform a prognosis and discussions with parents. Consideration of numerous environmental influences, for example, such as continuity and intensity of near work and time spent outdoors, may contribute to better risk estimation. Family-based practice appears to be ideally suited for risk estimation and the clinical application of approaches to control myopia. A proactive approach to estimating risk of developing myopia prior to its onset may be beneficial. Earlier implementation of interventions to control myopia could significantly reduce the chance of progression to pathological myopia.

Impact of parental history of myopia on the development of myopia in mainland china school-aged children

BACKGROUND

Myopia is a very common condition and a significant public health problem in China. The objective of the study was to explore the genetic influence on myopia in Mainland China school-aged children in Beijing.

METHODS

In 2008, the data from 15,316 Chinese school students aged 6–18 years from 19 randomized schools in Beijing were analyzed to evaluate genetic influence on myopia in children. Heritability was calculated by mid-parent–offspring regression and parent–offspring regression.

RESULTS

The estimate of heritability was 0.30 (95% CI, 0.27–0.33) for refractive value (RV). The adjusted mean refractive error was −2.33D (95% CI, −2.45 to −2.21) in children with two myopic parents compared with −1.13D (95% CI, −1.78 to −1.08) in children with no parental myopia. The adjusted odds ratio (OR) was 2.83 (95% CI, 2.47–3.24) in children with two myopic parents compared with no parental myopia.

CONCLUSION

The study found a strong association between parental history of myopia and genesis of myopia in the offspring even after adjusting for environmental factors.

PAX6 gene associated with high myopia: a meta-analysis

PURPOSE

The PAX6 gene is among the most studied genes in high myopia, but reported findings of association studies on PAX6 and high myopia are inconsistent. We conducted a systematic review and meta-analysis to evaluate the association of PAX6 polymorphisms and high myopia.

METHODS

All case-control association studies on PAX6 and high myopia reported in EMBASE and MEDLINE were retrieved. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for single-nucleotide polymorphisms (SNPs) that have been involved in at least two studies. Heterogeneity and publication bias analyses were also conducted.

RESULTS

There were totally 63 publications on PAX6 and myopia. Among them, six articles met all the inclusion criteria, involving 3626 patients and 3262 controls of Asian ancestry. Five PAX6 SNPs, rs3026354, rs667773, rs2071754, rs644242, and rs3026393, were meta-analyzed in high myopia and two, rs667773 and rs644242, in extreme myopia. Single-nucleotide polymorphism rs644242 was associated with high myopia in the dominant model (OR = 0.87; 95% CI, 0.76 to 0.99; p = 0.035) and heterozygous model (OR = 0.85; 95% CI, 0.74 to 0.97; p = 0.019) and with extreme myopia in the dominant model (OR = 0.79; 95% CI, 0.65 to 0.95; p = 0.015), allelic model (OR = 0.81; 95% CI, 0.68 to 0.96; p = 0.014), and heterozygous model (OR = 0.80; 95% CI, 0.65 to 0.97; p = 0.024). However, the associations cannot withstand Bonferroni correction (p > 0.005). The other four SNPs did not show significant association with high myopia.

CONCLUSIONS

Meta-analysis of existing data revealed a suggestive association of PAX6 rs644242 with extreme and high myopia, which awaits validation in further studies. Nevertheless, PAX6 may only confer a small effect to myopia development.

The impact of intermittent exotropia and surgery for intermittent exotropia on myopic progression among early school-aged children with myopia

AIM

To investigate the relationship between myopic progression and intermittent exotropia, and the impact of surgery for exotropia on myopic progression in early school-aged children (from 7 years to 12 years of age).

METHODS

Medical records of early school-aged patients with myopia were reviewed. Patients were divided into three groups; (A) Patients with intermittent exotropia and myopia at presentation and who underwent bilateral lateral rectus muscle recession for exotropia when 7-12 years old; (B) Patients with intermittent exotropia and myopia at presentation and who were merely observed for exotropia; and (C) Patients with myopia and straight ocular alignment. Main outcome measurements were the simple rate of myopic progression per year, the preoperative and postoperative rates of refractive growth with regards to the logarithmic age model in Group A, and the rate of high myopia development at the end of the early school period.

RESULTS

The rates of myopic progression were -0.43±0.14 dioptre (D) per year in Group A, -0.49±0.17 D/year in Group B and -0.42±0.24 D/year in Group C. There was no significant difference in the rate of myopic progression among three groups. There was no significant intergroup difference in the preoperative and postoperative rates of refractive growth in Group A. There were no significant intergroup differences in the rates of high myopia development among three groups.

CONCLUSIONS

Whether patients with intermittent exotropia underwent surgical correction for intermittent exotropia did not influence the rate of myopic progression. There was no significant difference in the rate of myopic progression between patients with accompanying intermittent exotropia and myopia and those with myopia alone.

Association study of IGF1 polymorphisms with susceptibility to high myopia in a Japanese population

PURPOSE

Polymorphisms in the insulin-like growth factor 1 (IGF1) gene were previously associated with high or extreme myopia in Caucasian and Chinese populations. In the present study, we investigated whether IGF1 polymorphisms are associated with high myopia in a Japanese population.

METHODS

A total of 446 Japanese patients with high myopia (≤-9.00 diopters) and 481 Japanese healthy controls (+1.50 diopters to -1.50 diopters) were recruited. We genotyped seven tagging single-nucleotide polymorphisms (SNPs) in IGF1 and assessed allelic and haplotypic diversity in cases and controls.

RESULTS

There were no statistically significant differences in the allele frequencies of IGF1 SNPs and genotypes between cases and controls (P>0.05). However, the A allele of rs5742629 and the G allele of rs12423791 were associated with a moderately increased risk of high myopia (odds ratio [OR] =1.20 and OR =1.21, respectively) with borderline statistical significance (P=0.0502, corrected P (Pc) =0.21 and P=0.064, Pc=0.29, respectively). The haplotype consisting of the A allele of rs5742629 and the G allele of rs12423791 was marginally associated with the risk of high myopia (P=0.041; OR =1.21); this association was not significant after correction (Pc=0.19).

CONCLUSION

We found that the IGF1 SNPs are not significantly associated with high myopia in our Japanese population. Our results are in contrast to a previous study in which extreme myopia cases had significantly higher frequencies of the G allele of rs5742629 and the C allele of rs12423791 than controls. Therefore, the IGF1 SNPs may not be important factors for susceptibility to high myopia in all populations. Further genetic studies are needed to elucidate the possible contributions of the IGF1 region to the development of high myopia.

Nearwork-induced transient myopia and parental refractive error

PURPOSE

To investigate the relationship between parental refractive error and the nearwork-induced transient myopia (NITM) characteristics of their children.

METHODS

Three hundred sixty children (173 boys and 187 girls) aged 6 to 17 years were tested. Initial NITM and its decay time (DT) were assessed objectively (WAM-5500, Grand-Seiko) immediately after binocularly viewing and performing a sustained near task (5 diopters [D]) for 5 minutes, incorporating a cognitive demand with full distance refractive correction in place. The NITM was classified into three categories: low (< 0.15 D), moderate (0.15 to 0.30 D), or high (≥0.30 D), whereas its decay was classified into two categories, namely, complete or incomplete. In addition, the children were divided into three groups based on the number of myopic parents (none, one, or two) and into four groups based on the level of parental myopia (no, low, moderate, or high).

RESULTS

Neither paternal nor maternal refractive error was associated with either their children's initial NITM magnitude or its DT in the myopic, emmetropic, or hyperopic groups or the combined group. No significant differences (p > 0.05) in the NITM magnitude, DT, or decay time constant were found as related to the number of myopic parents or level of parental myopia. Multiple odds ratio for incomplete decay of NITM did not change significantly (p > 0.05) with either an increase in number of myopic parents or level of parental myopia.

CONCLUSIONS

There was no association between parental refractive error and their children's NITM characteristics. This suggests a primary environmental basis for the NITM characteristics in the children.

Outdoor activity during class recess reduces myopia onset and progression in school children

PURPOSE

The aim of this study was to investigate the effect of outdoor activity during class recess on myopia changes among elementary school students in a suburban area of Taiwan.

DESIGN

Prospective, comparative, consecutive, interventional study.

PARTICIPANTS

Elementary school students 7 to 11 years of age recruited from 2 nearby schools located in a suburban area of southern Taiwan.

INTERVENTION

The children of one school participated in the interventions, whereas those from the other school served as the control group. The interventions consisted of performing a recess outside the classroom (ROC) program that encouraged children to go outside for outdoor activities during recess. The control school did not have any special programs during recess.

MAIN OUTCOME MEASURES

Data were obtained by means of a parent questionnaire and ocular evaluations that included axial length and cycloplegic autorefraction at the beginning and after 1 year.

RESULTS

Five hundred seventy-one students were recruited for this study, of whom 333 students participated in the interventional program, and 238 students were in the control school. At the beginning of the study, there were no significant differences between these 2 schools with regard to age, gender, baseline refraction, and myopia prevalence (47.75% vs. 49.16%). After 1 year, new onset of myopia was significantly lower in the ROC group than in the control group (8.41% vs. 17.65%; P<0.001). There was also significantly lower myopic shift in the ROC group compared with the control group (-0.25 diopter [D]/year vs. -0.38 D/year; P = 0.029). The multivariate analysis demonstrated that the variables of intervention of the ROC program and higher school year proved to be a protective factor against myopia shift in nonmyopic subjects (P = 0.020 and P = 0.017, respectively). For myopic subjects, school year was the only variable significantly associated with myopia progression (P = 0.006).

CONCLUSIONS

Outdoor activities during class recess in school have a significant effect on myopia onset and myopic shift. Such activities have a prominent effect on the control of myopia shift, especially in nonmyopic children.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

The impact of severity of parental myopia on myopia in Chinese children

PURPOSE

To assess the impact of severity of parental myopia on myopia in Chinese children.

METHODS

Children aged 12 to 15 years were identified from a population-based sample in Guangzhou. Children's myopia was defined as a spherical equivalent refraction of ≤0.5 D based on cycloplegic (1% cyclopentolate) autorefraction. Using a questionnaire reported by the parents, the parental myopia was confirmed and the severity of myopia on the right eyes was classified into mild (<3.0 D myopia), moderate (3.0 to 6.0 D myopia), and high (>6.0 D myopia) myopia.

RESULTS

Information was available for 1567 children aged 12 to 15 years. Analysis was restricted to children with no myopia in one parent and no, mild, moderate, or high myopia in the other. The prevalence of myopia in children was 53.5, 65.1, 76.3, and 80.6% when the severity of myopia in the second parent was no, mild, moderate, and high, and the prevalence of high myopia (spherical equivalent >6.0 D myopia) in children was 1.4, 2.9, 8.5, and 16.1% in the corresponding groups of parental myopia severity. Of the children with high myopia, 45.3% had parents with no reported myopia.

CONCLUSIONS

More severe myopia in one parent results in an increased risk of myopia in the children. However, most highly myopic children did not have a highly myopic parent and also half did not have any reported parental myopia. This suggests that while genetic factors contribute to the development of more severe myopia, environmental factors also contribute to high myopia in children in Guangzhou.

One year study on the integrative intervention of acupressure and interactive multimedia for visual health in school children

OBJECTIVE

This study used a larger sample size, added a long-term observation of the effect of intervention, and provided an integrated intervention of acupressure and interactive multimedia of visual health instruction for school children. The short- and long-term effects of the interventions were then evaluated by visual health knowledge, visual acuity, and refractive error.

DESIGN

A repeated pretest-posttest controlled trial was used with two experimental groups and one control group.

SETTING

Four elementary schools in northern Taiwan.

PARTICIPANTS

287 School children with visual impairment in fourth grade were recruited.

METHOD

One experimental group received the integrative intervention of acupressure and interactive multimedia of visual health instruction (ACIMU), and another received auricular acupressure (AC) alone; whereas a control group received no intervention. Two 10-week interventions were separately given in the fall and spring semesters. The short- and long-term effects of the interventions were then evaluated by visual health knowledge, visual acuity, and refractive error.

RESULTS

During the school year the visual health knowledge was significantly higher in the ACIMU group than the control group (p<0.001). A significant difference in the changing visual acuity was in the three groups (p<0.001), with the improvement in the ACIMU group. No difference in the refractive error was found between any two groups (p>0.05).

CONCLUSIONS

This study demonstrated that a long-term period of acupressure is required to improve school children's visual health. School children receiving the intervention of acupressure combined with interactive multimedia had better improvement of visual health and related knowledge than others. Further study is suggested in which visual health and preventative needs can be established for early childhood.