Incident Myopia Research Articles

Associations of incident myopia and its development with related factors among school-aged children across different grades: a four-year longitudinal study.

To assess the progression of myopia across different academic grades and investigate the associations between potential myopia-related factors and the incidence of myopia at various grade levels. We utilized data from an ongoing longitudinal study that began with grade 1 students across 12 schools. Four waves of annual eye examinations and questionnaire surveys were conducted. Longitudinal analyses were performed on three groups: Group 1 (n = 1223, non-myopic in grade 1) examined factors in grade 1 associated with incident myopia in grade 2; Group 2 (n = 653, non-myopic in grade 2) investigated factors in grade 2 related to incident myopia in grade 3; and Group 3 (n = 746, non-myopic in grade 3) evaluated factors in grade 3 associated with incident myopia in grade 4. The incidence of myopia increased from 4.3% in grade 2 to 21.6% in grade 4. Our findings revealed a consistent positive association between the number of myopic parents and incident myopia in grades 2, 3, and 4, respectively. Outdoor activity in earlier grades showed significant protective effects, reducing the risk of incident myopia in the subsequent grades 2 and 3 (e.g., in Group 1, adjusted HR 0.46 [95% CI 0.24 ~ 0.86]). However, no significant association was observed between outdoor activity in grade 3 and incident myopia in grade 4. It is important to consider the grade level of schoolchildren when addressing myopia control. Implementing early-phase interventions, particularly those emphasizing outdoor activities, may help mitigate the onset and progression of myopia during the earlier school years.

Topical Atropine for Myopia Control: A Review.

Over the past decade, atropine has emerged as an effective intervention for preventing myopia in children. Multiple randomized controlled trials, mainly from Asia, have demonstrated the safety and efficacy of topical atropine for myopia control. Both efficacy and side effects exhibit a positive dose-response relationship. This review focuses on new data from studies with predominantly white populations, ethnicity-dependent differences in efficacy and side effects, and primary prevention of incident myopia with atropine.

The Onset and Progression of Myopia Slows in Chinese 15-Year-Old Adolescents Following Vocational Rather Than Academic School Pathways.

The purpose of this study was to investigate the changes in spherical equivalent (SE) and axial length (AL) and cumulative incidence of myopia and high myopia in Chinese 15-year-old adolescents entering a non-academic stream of senior high school education. A total of 880 first-born twins with a baseline age range of 7 to 15 years were enrolled and followed annually until 18 years of age. Cycloplegic refractions and AL were examined. Educational exposure was divided into academic high school (AHS) and vocational high school (VHS) streams. A piecewise linear mixed-effects model was used to estimate the effect of education exposures on SE development, the slope before the age of 15 years (β2), and the slope change at the age of 15 years (β3) was compared between the 2 groups. The curves of refractive development in a myopic direction changed in parallel in the AHS and VHS group before 15 years. For nonmyopic children, β2 was -0.19 and -0.20 diopters (D)/year (P = 0.270), and β3 was 0.16 and 0.14 D/year (P = 0.270), in the AHS and VHS groups, respectively. Among patients with myopia, β2 was -0.52 and -0.54 D/year (P = 0.500), and β3 was 0.37 and 0.32 D/year (P = 0.004), in the AHS and VHS groups, respectively. The trends in AL were similar. The 3-year cumulative incidence of myopia was 35.3% (AHS) versus 14.7% (VHS; P < 0.001), and that of high myopia was 5.7% and 3.3% (P = 0.129). Students undertaking a VHS rather than an AHS education have slower myopic shifts in refraction and less incident myopia after the age of 15 years.

Effect of artificial natural light on the development of myopia among primary school-age children in China: a three-year longitudinal study.

To assess the efficacy of artificial natural light in preventing incident myopia in primary school-age children. This is a prospective, randomized control, intervention study. A total of 1840 students from 39 classes in 4 primary schools in Foshan participated in this study. The whole randomization method was adopted to include classes as a group according to 1:1 randomized control. Classrooms in the control group were illuminated by usual light, and classrooms in the intervention group were illuminated by artificial natural light. All students received uncorrected visual acuity and best-corrected visual acuity measurement, non-cycloplegic autorefraction, ocular biometric examination, slit lamp and strabismus examination. Three-year follow-up, the students underwent same procedures. Myopia was defined as spherical equivalent refraction ≤ -0.50 D and uncorrected visual acuity <20/20. There were 894 students in the control group and 946 students in the intervention group with a mean±SD age of 7.50±0.53y. The three-year cumulative incidence rate of myopia was 26.4% (207 incident cases among 784 eligible participants at baseline) in the control group and 21.2% (164 incident cases among 774 eligible participants at baseline) in the intervention group [difference of 5.2% (95%CI, 3.7% to 10.1%); P=0.035]. There was also a significant difference in the three-year change in spherical equivalent refraction for the control group (-0.81 D) compared with the intervention group [-0.63 D; difference of 0.18 D (95%CI, 0.08 to 0.28 D); P<0.001]. Elongation of axial length was significantly different between in the control group (0.77 mm) and the intervention group [0.72 mm; difference of 0.05 mm (95%CI, 0.01 to 0.09 mm); P=0.003]. Artificial natural light in the classroom of primary schools can result in reducing incidence rate of myopia during a period of three years.

Green Space Morphology and School Myopia in China

China has experienced both rapid urbanization and major increases in myopia prevalence. Previous studies suggest that green space exposure reduces the risk of myopia, but the association between myopia risk and specific geometry and distribution characteristics of green space has yet to be explored. These must be understood to craft effective interventions to reduce myopia. To evaluate the associations between myopia and specific green space morphology using novel quantitative data from high-resolution satellite imaging. This prospective cohort study included students grades 1 to 4 (aged 6 to 9 years) in Shenzhen, China. Baseline data were collected in 2016-2017, and students were followed up in 2018-2019. Data were analyzed from September 2020 to January 2022. Eight landscape metrics were calculated using land cover data from high-resolution Gaofen-2 satellite images to measure area, aggregation, and shape of green space. The 2-year cumulative change in myopia prevalence at each school and incidence of myopia at the student level after 2 years were calculated as main outcomes. The associations between landscape metrics and school myopia were assessed, controlling for geographical, demographic, and socioeconomic factors. Principal component analyses were performed to further assess the joint effect of landscape metrics at the school and individual level. A total of 138 735 students were assessed at baseline. Higher proportion, aggregation, and better connectivity of green space were correlated with slower increases in myopia prevalence. In the principal component regression, a 1-unit increase in the myopia-related green space morphology index (the first principal component) was negatively associated with a 1.7% (95% CI, -2.7 to -0.6) decrease in myopia prevalence change at the school level (P = .002). At the individual level, a 1-unit increase in myopia-related green space morphology index was associated with a 9.8% (95% CI, 4.1 to 15.1) reduction in the risk of incident myopia (P < .001), and the association remained after further adjustment for outdoor time, screen time, reading time, and parental myopia (adjusted odds ratio, 0.88; 95% CI, 0.80 to 0.97; P = .009). Structure of green space was associated with a decreased relative risk of myopia, which may provide guidance for construction and renovation of schools. Since risk estimates only indicate correlations rather than causation, further interventional studies are needed to assess the effect on school myopia of urban planning and environmental designs, especially size and aggregation metrics of green space, on school myopia.

Effects of school myopia management measures on myopia onset and progression among Chinese primary school students

BackgroundSchools play an organizational role in managing myopia-related behavioral habits among students. We evaluated the effects of school myopia management measures on myopia onset and progression in a school-based prospective 1-year observational study.MethodsIn total, 8319 children from 26 elementary schools were included. Online questionnaire completed by a parent, in which school myopia management experience including outdoor activities in recess or physical education class, teachers’ supervision, and teaching facilities. Variables were defined as implemented well or poorly, according to the Comprehensive Plan to Prevent Myopia among Children and Teenagers. Children underwent ophthalmic examinations, and the incidence and progression of myopia from 2019 to 2020 were estimated. Multilevel logistic regression models were constructed to analyze the association between school management measures and myopia development in 8,9 years and 10,11 years students.ResultsFrom 2019 to 2020, the incidence of myopia among primary school students was 36.49%; the mean difference of spherical equivalent in myopic children was − 0.29 ± 1.22 diopters. The risk of incident myopia was reduced by 20% in 8,9 years participants with well-implemented class recess compared with those with poorly implemented class recess (adjusted odds ratio [aOR]: 0.80, p = 0.032). PE outdoor time was significantly associated with myopia incidence in 10,11 years students (aOR: 0.76, p = 0.043). Compared with poorly implemented reading and writing posture, desk and chair height, 10,11 participants with well-implemented desk and chair height were less likely to have rapid myopic progression (p = 0.029, p = 0.022).ConclusionIn Shanghai, children’s myopia is associated with better implementation of school myopia management measures. The present findings suggest that outdoor activities during class recess or PE class, providing suitable desks and chairs, and adequate instruction in reading and writing postures might protect against pathological eye growth. An age-specific myopia prevention and control programs in school is of primary importance.

Baseline Refractive Error, Habitual Accommodative Tone, and Its Association With Myopia in Children: The Lhasa Childhood Eye Study.

The purpose of this study was to describe the baseline refractive error, habitual accommodative tone (HAT) in Tibetan children and its longitudinal association with incident myopia and myopia progression. This was a prospective cohort study. From 7 elementary schools, 1440 children with mean age of 6.83 ± 0.46 years were included with full noncycloplegic and cycloplegic refraction data at baseline, 1-year and 2-year follow-up in the Lhasa Childhood Eye Study. Noncycloplegic and cycloplegic automated refraction were performed at baseline and annually over the next 2 years. HAT was measured as the difference in spherical equivalent (DSE) between noncycloplegic and cycloplegic refraction. The mean HAT decreased from a baseline value of 0.92 ± 0.82 diopters (D) to 0.55 ± 0.65 D, P < 0.0001 at 2 years. In multivariable logistic regression models, only baseline spherical equivalent (SE; P < 0.0001) was significantly (negatively) associated with 1- and 2-year incident myopia. Among 1386 children without myopia at baseline, 271 developed myopia over 2 years. For hyperopic children, baseline HAT was significantly associated with the incidence of myopia over 2 years (odds ratio [OR] = 0.43, P < 0.001), and the incidence of myopia was significantly lower with baseline HAT ≥0.5D, compared to children <0.5 D. For 54 (3.75%) children who were myopic at baseline, SE was significant positively associated with myopic progression in univariable (P = 0.03) and multivariable general mixed linear regression analysis (P = 0.03). Baseline SE was an independent influencing factor for the incidence of myopia and its progression. The incidence of myopia was significantly higher with lower baseline HAT among hyperopic children, indicating that lower HAT was potentially associated with myopic development.

Effect of Repeated Low-level Red Light on Myopia Prevention Among Children in China With Premyopia

Myopia is a global concern, but effective prevention measures remain limited. Premyopia is a refractive state in which children are at higher risk of myopia, meriting preventive interventions. To assess the efficacy and safety of a repeated low-level red-light (RLRL) intervention in preventing incident myopia among children with premyopia. This was a 12-month, parallel-group, school-based randomized clinical trial conducted in 10 primary schools in Shanghai, China. A total of 139 children with premyopia (defined as cycloplegic spherical equivalence refraction [SER] of -0.50 to 0.50 diopter [D] in the more myopic eye and having at least 1 parent with SER ≤-3.00 D) in grades 1 to 4 were enrolled between April 1, 2021, and June 30, 2021; the trial was completed August 31, 2022. Children were randomly assigned to 2 groups after grade stratification. Children in the intervention group received RLRL therapy twice per day, 5 days per week, with each session lasting 3 minutes. The intervention was conducted at school during semesters and at home during winter and summer vacations. Children in the control group continued usual activities. The primary outcome was the 12-month incidence rate of myopia (defined as SER ≤-0.50 D). Secondary outcomes included the changes in SER, axial length, vision function, and optical coherence tomography scan results over 12 months. Data from the more myopic eyes were analyzed. Outcomes were analyzed by means of an intention-to-treat method and per-protocol method. The intention-to-treat analysis included participants in both groups at baseline, while the per-protocol analysis included participants in the control group and those in the intervention group who were able to continue the intervention without interruption by the COVID-19 pandemic. There were 139 children (mean [SD] age, 8.3 [1.1] years; 71 boys [51.1%]) in the intervention group and 139 children (mean [SD] age, 8.3 [1.1] years; 68 boys [48.9%]) in the control group. The 12-month incidence of myopia was 40.8% (49 of 120) in the intervention group and 61.3% (68 of 111) in the control group, a relative 33.4% reduction in incidence. For children in the intervention group who did not have treatment interruption secondary to the COVID-19 pandemic, the incidence was 28.1% (9 of 32), a relative 54.1% reduction in incidence. The RLRL intervention significantly reduced the myopic shifts in terms of axial length and SER compared with the control group (mean [SD] axial length, 0.30 [0.27] mm vs 0.47 [0.25] mm; difference, 0.17 mm [95% CI, 0.11-0.23 mm]; mean [SD] SER, -0.35 [0.54] D vs -0.76 [0.60] D; difference, -0.41 D [95% CI, -0.56 to -0.26 D]). No visual acuity or structural damage was noted on optical coherence tomography scans in the intervention group. In this randomized clinical trial, RLRL therapy was a novel and effective intervention for myopia prevention, with good user acceptability and up to 54.1% reduction in incident myopia within 12 months among children with premyopia. ClinicalTrials.gov Identifier: NCT04825769.

Dietary Patterns and Associations with Myopia in Chinese Children

Dietary shifts in populations undergoing rapid economic transitions have been proposed as partly contributing toward the rapid intergenerational rise in myopia prevalence; however, empirical evidence of the effect of dietary factors on myopia is limited. This study investigated the association between dietary factors and incident myopia in Chinese children aged 10-11 years. We evaluated dietary habits using a 72-item food frequency questionnaire (FFQ) among 7423 children. Myopic status was assessed using the "General Personal Information Questionnaire". Principal component analysis was used to extract dietary patterns and investigate their association with myopia. After adjusting for potential confounders, participants with the highest adherence to dietary pattern A (95% confidence interval (CI): 0.66-0.92, p for trend = 0.007) and dietary pattern C (95% CI: 0.58-0.80, p for trend < 0.001) had a lower risk of myopia than participants with the least adherence. Both of these dietary patterns are characterized by high consumption of meats, aquatic product, dairy and its products, eggs, legumes, vegetables, fruits, grains, and potatoes. Our findings suggest that other environmental factors, such as those related to the dietary environment, may contribute to the development of myopia. These findings can serve as a reference for diet-related primary prevention of myopia.

Relative peripheral refraction and its role in myopia onset in teenage students.

To characterize peripheral refraction and its relationship with myopia development in a selected group of male teenage Chinese students. This 2-year prospective cohort study randomly enrolled 85 non-myopic boys (age, 14-16y) from the Experimental Class of Air Force in China. Cycloplegic peripheral refraction was examined at 0°, ±10°, and ±20° along the horizontal visual field in the right eye at the baseline and 2-year follow-up. The incidence of myopia at the 2-year follow-up was 15.29% (13/85). The baseline central refraction (CR) and peripheral refraction at ±10° were significantly lower in students who developed myopia than in those who did not (P<0.05). Relative peripheral refraction (RPR) did not differ between students with and without myopia (P>0.05). At the 2-year follow-up, the RPR at ±10° and 20° nasal was significantly more hyperopic in the myopic group than in the non-myopic group. Multiple linear regression analysis indicated that the change in CR was significantly correlated with the changes in RPR at 20° nasal, 10° nasal, and 20° temporal. Multivariate Logistic regression analysis indicated that the baseline CR [odds ratio (OR): 0.092, 95% confidence interval (CI): 0.012-0.688, P=0.020] and the baseline RPR at 10° nasal (OR: 0.182, 95%CI: 0.042-0.799, P=0.024) were significantly correlated with incident myopia (Omnibus test, χ 2=10.20, P=0.006). CR change is significantly correlated with changes in RPR, and students who develop myopia have more relative peripheral hyperopia. More baseline CR and relative peripheral hyperopia at 10° nasal are protective of myopia onset.

Effect of outdoor time on the incidence of myopia among primary school students in 9 provinces of China

Objective: We aimed to assess the effects of outdoor time in preventing incident myopia among primary school students and evaluate its differences among different grades to provide evidence for policy formulation related to myopia prevention. Methods: This study is a cohort study. We investigated 6 046 grade 1 to 5 students in 9 provinces, Jiangsu, Shanghai, Fujian, Shanxi, Henan, Hunan, Gansu, Chongqing, and Guangxi. In 2019, we measured their myopia on site. In 2020, we did a follow-up visit on those students to detect the myopia incidence rate. Information regarding outdoor time and myopia-related behaviors were obtained from a questionnaire within one week of visual acuity measurement in 2020. The chi-square test and Cochran-Armitage trend test compared the differences between groups. The Cox proportional hazards risk model was used to test the relationship between outdoor time and myopia. Results: In 2020, the overall myopia incidence rate of grade 1 to 5 students in the baseline was 27.5%; while 23.0% in grades 1 and 2 students and 31.7% in grades 3 to 5 students, respectively. After controlling for covariates, for students in grade 1 to 2, those with ≥1 hour of outdoor time per day were at 0.76 (95%CI: 0.62-0.93, P=0.008) times risk of being myopia than that of students with <1 hour of outdoor time per day; while for students in grades 3 to 5, an average of ≥3 hours of outdoor time per day was required to have a significant protective effect on myopia. The students with ≥3 hours of outdoor time per day were less likely to be myopia (OR=0.75, 95%CI: 0.61-0.93, P=0.007) than those students with <3 hours of outdoor time per day. Conclusions: For grade 1 and 2 students, 1 hour of outdoor time per day could reduce the incidence of myopia, whereas for grade 3 to 5 students, 3 hours of outdoor time per day could effectively reduce the incidence of myopia. Therefore, the recommendations for outdoor time as myopia prevention should be different for different grades. The higher the grade is, the more outdoor time should be spent to reduce myopia incidence. Moreover, other factors that affect myopia's incidence should be also paid attention to, and a comprehensive approach should be adopted to prevent and control the incidence of myopia.

Time spent outdoors as an intervention for myopia prevention and control in children: an overview of systematic reviews.

PurposeOutdoor light exposure is considered a safe and effective strategy to reduce myopia development and aligns with existing public health initiatives to promote healthier lifestyles in children. However, it is unclear whether this strategy reduces myopia progression in eyes that are already myopic. This study aims to conduct an overview of systematic reviews (SRs) reporting time spent outdoors as a strategy to prevent myopia or slow its progression in children.MethodsWe searched the Cochrane Library, EMBASE, MEDLINE and CINAHL from inception to 1 November 2020 to identify SRs that evaluated the association between outdoor light exposure and myopia development or progression in children. Outcomes included incident myopia, prevalent myopia and change in spherical equivalent refraction (SER) and axial length (AL) to evaluate annual rates of myopia progression. The methodological quality and risk of bias of included SRs were assessed using the AMSTAR‐2 and ROBIS tools, respectively.ResultsSeven SRs were identified, which included data from 47 primary studies with 63,920 participants. Pooled estimates (risk or odds ratios) consistently demonstrated that time outdoors was associated with a reduction in prevalence and incidence of myopia. In terms of slowing progression in eyes that were already myopic, the reported annual reductions in SER and AL from baseline were small (0.13–0.17 D) and regarded as clinically insignificant. Methodological quality assessment using AMSTAR‐2 found that all reviews had one or more critical flaws and the ROBIS tool identified a low risk of bias in only two of the included SRs.ConclusionThis overview found that increased exposure to outdoor light reduces myopia development. However, based on annual change in SER and AL, there is insufficient evidence for a clinically significant effect on myopia progression. The poor methodological quality and inconsistent reporting of the included systematic reviews reduce confidence in the estimates of effect.

Interactions between genetic variants and near-work activities in incident myopia in schoolchildren: a 4-year prospective longitudinal study

ABSTRACTClinical relevanceKnowledge of interactions between genetic variants and near-work activities at the onset of myopia can facilitate health education regarding myopia.BackgroundTo investigate the interactions between genetic variants (PDE10A, AREG and GABRR1) and near-work activities in the onset of myopia in southeastern Chinese school children.MethodsA total of 458 non-myopic, grade 1 children aged 6–7 years were included in a 4-year follow-up examination; 409 children were assessed further. Manifest (non-cycloplegic) refraction and axial length (AL) were measured every year, and questionnaires were administered annually to assess information regarding the demographic characteristics of children, near-work activities, outdoor exposure and parental myopia. Oral mucosa was collected in the last year of follow-up, and Sanger sequencing was used to genotype single nucleotide polymorphisms (SNPs) in DNA.ResultsThe cumulative change in the spherical equivalent refraction (SER) over 4 years was −1.20 ± 1.00 D, and the proportion of children with incident myopia was 42.9%. Multivariate logistic regression analysis showed that an increased amount of time spent doing homework (>2 h/d) was an independent risk factor for incident myopia. The PDE10A rs12206610CT genotype and spending > 5 h/d on near-work activities showed an interaction for incident myopia (OR = 4.29, 95% CI: 1.27-14.53; Pinteraction = 0.02); moreover, the rs12206610CT genotype carriers who used electronic devices for > 1 h/d displayed an increased risk of incident myopia (OR = 3.43, 95% CI: 1.07-11.01; Pinteraction = 0.043).ConclusionsThe rs2206610CT genotype carriers with near-work activities of >5 h/d were more likely to show incident myopia, especially those who used electronic devices >1 h/d. However, interactions between the rs12206610 SNP and near-work activities require further verification in animal models and larger sample cohorts.

Incidence and Progression of Myopia in Early Adulthood

Myopia incidence and progression has been described extensively in children. However, few data exist regarding myopia incidence and progression in early adulthood. To describe the 8-year incidence of myopia and change in ocular biometry in young adults and their association with the known risk factors for childhood myopia. The Raine Study is a prospective single-center cohort study. Baseline and follow-up eye assessments were conducted from January 2010 to August 2012 and from March 2018 to March 2020. The data were analyzed from June to July 2021. A total of 1328 participants attended the baseline assessment, and 813 participants attended the follow-up assessment. Refractive information from both visits was available for 701 participants. Participants with keratoconus, previous corneal surgery, or recent orthokeratology wear were excluded. Participants' eyes were examined at ages 20 years (baseline) and 28 years. Incidence of myopia and high myopia; change in spherical equivalent (SE) and axial length (AL). A total of 516 (261 male [50.6%]) and 698 (349 male [50.0%]) participants without myopia or high myopia at baseline, respectively, were included in the incidences analyses, while 691 participants (339 male [49%]) were included in the progression analysis. The 8-year myopia and high myopia incidence were 14.0% (95% CI, 11.5%-17.4%) and 0.7% (95% CI, 0.3%-1.2%), respectively. A myopic shift (of 0.50 diopters [D] or greater in at least 1 eye) occurred in 261 participants (37.8%). Statistical significance was found in longitudinal changes in SE (-0.04 D per year; P < .001), AL (0.02 mm per year; P <.001), and lens thickness (0.02 mm per year; P < .001). Incident myopia was associated with self-reported East Asian vs White race (odds ratio [OR], 6.13; 95% CI, 1.06-35.25; P = .04), female vs male sex (OR, 1.81; 95% CI, 1.02-3.22; P = .04), smaller conjunctival ultraviolet autofluorescence area (per 10-mm2 decrease, indicating less sun exposure; OR, 9.86; 95% CI, 9.76-9.97; P = <.009), and parental myopia (per parent; OR, 1.57; 95% CI, 1.03-2.38; P = <.05). Rates of myopia progression and axial elongation were faster in female participants (estimate: SE, 0.02 D per year; 95 % CI, 0.01-0.02 and AL, 0.007 mm per year, 95 % CI, 0.00.-0.011; P ≤ .001) and those with parental myopia (estimate per parent: SE, 0.01 D per year; 95% CI, 0.00-0.02 and AL, 95% CI, 0.002-0.008; P ≤ .001). Education level was not associated with myopia incidence or progression. These findings suggest myopia progression continues for more than one-third of adults during the third decade of life, albeit at lower rates than during childhood. The protective effects of time outdoors against myopia may continue into young adulthood.

Time-Varying Associations of Incident Myopia and Myopia Development with its Associated Factors in School-Aged Children: A Four-Year Longitudinal Study

Time-Varying Associations of Incident Myopia and Myopia Development with its Associated Factors in School-Aged Children: A Four-Year Longitudinal Study

Dietary intake and associations with myopia in Singapore children.

To evaluate associations of dietary factors with myopia, spherical equivalent refractive error (SE) and axial length (AL) in children at age 9 from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort. We included 467multi-ethnic children (933 eyes) who participated in the GUSTO prospective birth cohort and were delivered in two major hospitals in Singapore (2009-2010). At the 9-year visit, we assessed the 6-year incidence of myopia (between ages 3 to 9), cycloplegic SE and AL in children without myopia (SE≤-0.5D in either eye) at the 3-year visit. Using a validated 112-item food frequency questionnaire, parents reported each child's average daily intake of dietary factors (nutrients and food groups) in the past month. Paired eyes were analysed using Generalised Estimating Equations with multivariable logistic or linear regression. Bonferroni corrections were applied, correcting for multiple comparisons between the 13 nutrients (p<0.004) or 8 food groups (p<0.006) and each outcome. In children aged 9years (51.0% boys; 56.3% Chinese), the 6-year incidence of myopia was 35.5%. Overall, the mean (SD) SE and AL were -0.3 (1.7)D and 23.4 (1.0)mm, respectively. In multivariable regression, macronutrients or micronutrients were not associated with incident myopia (p≥0.004 for all), adjusting for total energy, gender, ethnicity, time outdoors, near-work and the number of myopic parents (additionally child's height for outcome AL). Similarly, all food groups (including refined grains, sugar-sweetened beverages, protein foods, fruits and vegetables) were not associated with incident myopia (p≥0.006 for all). Additionally, none of the nutrients (p≥0.004 for all) or food groups (p≥0.006 for all) were associated with SE or AL. Our study findings of no significant association between specific nutrients or food groups and incident myopia or SE or AL suggest that diet may not be associated with myopia in children aged 9years. Well-conducted prospective studies in other populations may clarify the association.

Association between digital smart device use and myopia: a systematic review and meta-analysis

Excessive use of digital smart devices, including smartphones and tablet computers, could be a risk factor for myopia. We aimed to review the literature on the association between digital smart device use and myopia. In this systematic review and meta-analysis we searched MEDLINE and Embase, and manually searched reference lists for primary research articles investigating smart device (ie, smartphones and tablets) exposure and myopia in children and young adults (aged 3 months to 33 years) from database inception to June 2 (MEDLINE) and June 3 (Embase), 2020. We included studies that investigated myopia-related outcomes of prevalent or incident myopia, myopia progression rate, axial length, or spherical equivalent. Studies were excluded if they were reviews or case reports, did not investigate myopia-related outcomes, or did not investigate risk factors for myopia. Bias was assessed with the Joanna Briggs Institute Critical Appraisal Checklists for analytical cross-sectional and cohort studies. We categorised studies as follows: category one studies investigated smart device use independently; category two studies investigated smart device use in combination with computer use; and category three studies investigated smart device use with other near-vision tasks that were not screen-based. We extracted unadjusted and adjusted odds ratios (ORs), β coefficients, prevalence ratios, Spearman's correlation coefficients, and p values for associations between screen time and incident or prevalent myopia. We did a meta-analysis of the association between screen time and prevalent or incident myopia for category one articles alone and for category one and two articles combined. Random-effects models were used when study heterogeneity was high (I2>50%) and fixed-effects models were used when heterogeneity was low (I2≤50%). 3325 articles were identified, of which 33 were included in the systematic review and 11 were included in the meta-analysis. Four (40%) of ten category one articles, eight (80%) of ten category two articles, and all 13 category three articles used objective measures to identify myopia (refraction), whereas the remaining studies used questionnaires to identify myopia. Screen exposure was measured by use of questionnaires in all studies, with one also measuring device-recorded network data consumption. Associations between screen exposure and prevalent or incident myopia, an increased myopic spherical equivalent, and longer axial length were reported in five (50%) category one and six (60%) category two articles. Smart device screen time alone (OR 1·26 [95% CI 1·00-1·60]; I2=77%) or in combination with computer use (1·77 [1·28-2·45]; I2=87%) was significantly associated with myopia. The most common sources of risk of bias were that all 33 studies did not include reliable measures of screen time, seven (21%) did not objectively measure myopia, and nine (27%) did not identify or adjust for confounders in the analysis. The high heterogeneity between studies included in the meta-analysis resulted from variability in sample size (range 155-19 934 participants), the mean age of participants (3-16 years), the standard error of the estimated odds of prevalent or incident myopia (0·02-2·21), and the use of continuous (six [55%] of 11) versus categorical (five [46%]) screen time variables INTERPRETATION: Smart device exposure might be associated with an increased risk of myopia. Research with objective measures of screen time and myopia-related outcomes that investigates smart device exposure as an independent risk factor is required. None.

Axial length change and its relationship with baseline choroidal thickness \u2013 a five-year longitudinal study in Danish adolescents: the CCC2000 eye study

BackgroundMyopic eyes are longer than nonmyopic eyes and have thinner choroids. The purpose of present study was to investigate whether a thinner subfoveal choroid at 11 years of age predicted axial eye elongation and myopia during adolescence.MethodsLongitudinal, population-based observational study. Axial length was measured using an interferometric device and choroidal thickness was measured by spectral-domain optical coherence tomography. Myopia was defined as non-cycloplegic subjective spherical equivalent refraction ≤ − 0.50 diopters.ResultsRight eyes of 714 children (317 boys) were examined at age (median (IQR)) 11.5 (0.6) years and 16.6 (0.3) years during which axial length (median (IQR)) increased by 243 (202) μm in eyes without myopia (n = 630) at baseline compared with 454 (549) μm in eyes with myopia (n = 84) at baseline, p < 0.0001. A thicker baseline subfoveal choroid was associated with increased five-year axial elongation after adjustment for baseline axial length in nonmyopic eyes (β = 27 μm/100 μm, 95%CI 6 to 48, p = 0.011) but not in myopic eyes (p = 0.34). Subfoveal choroidal thickness at 11 years of age did not predict incident myopia at 16 years of age (p = 0.11). Longer baseline axial length was associated with greater five-year axial elongation in both myopic (β = 196 μm/mm, 95%CI 127 to 265, p < 0.0001) and nonmyopic eyes (β = 28 μm/mm, 95%CI 7 to 49, p = 0.0085) and the odds for incident myopia increased with 1.57 (95%CI 1.18 to 2.09, p = 0.0020) per mm longer axial length at baseline.ConclusionA thin subfoveal choroid at age 11 years did not predict axial eye elongation and incident myopia from age 11 to 16 years. A longer eye at age 11 years was associated with greater subsequent axial eye elongation and with increased risk of incident myopia at age 16 years.

Genome-Wide Association of Genetic Variants With Refraction, Axial Length, and Corneal Curvature: A Longitudinal Study of Chinese Schoolchildren.

BackgroundMyopia is a common eye disorder that is approaching epidemic proportions worldwide. A genome-wide association study identified AREG (rs12511037), GABRR1 (rs13215566), and PDE10A (rs12206610) as being associated with refractive error in Asian populations. The present study investigated the associations between these three genetic variants and the occurrence and development of myopia, spherical equivalent refraction (SER), axial length (AL), and corneal curvature (CC) in a cohort of southeastern Chinese schoolchildren.MethodsWe examined and followed 550 children in grade 1 enrolled in the Wenzhou Epidemiology of Refractive Error (WERE) project. During the 4-year follow-up, non-cycloplegic refraction was evaluated twice each year, and the AL and CC were measured once every year. Age, sex, and the amounts of time spent on near work and outdoors were documented with a questionnaire. Sanger DNA sequencing was used to genotype single nucleotide polymorphisms (SNPs). SNPtest software was used to identify potential genetic variants associated with myopia, SER, AL, and CC. Ten thousand permutations were used to correct for multiple testing.ResultsIn total, 469 children, including 249 (53.1%) boys and 220 (46.9%) girls, were included in analyses. The mean age of all the children was 6.33 ± 0.48 years. After adjusting for age, sex, time spent on near work and time spent outdoors, neither the genotypes nor the allele frequencies of the three SNPs were significantly associated with myopic shift, incident myopia or the change in SER. After adjusting for age, sex, near-work time and outdoor time with 10,000 permutations, the genotype AREG (rs12511037) was associated with an increase in AL (P′-values for the dominant, recessive, additive and general models were 0.0032, 0.0275, 0.0045, and 0.0099, respectively); the genotype PDE10A (rs12206610) was associated with a change in CC in the additive (P′ = 0.0096), dominant (P′ = 0.0096), and heterozygous models (P′ = 0.0096).ConclusionThese findings preliminarily indicate that AREG SNP rs12511037 and PDE10A SNP rs12206610 are etiologically relevant for ocular traits, providing a basis for further exploration of the development of myopia and its molecular mechanism. However, elucidating the role of AREG and PDE10A in the pathogenesis of myopia requires further animal model and human genetic epidemiology studies. This trial is registered as ChiCTR1900020584 at www.Chictr.org.cn.

The association between digital screen time and myopia: A systematic review.

Digital screen time has been cited as a potential modifiable environmental risk factor that can increase myopia risk. However, associations between screen time and myopia have not been consistently reported. Although myopia prevalence increased before the massive use of digital devices in some countries, with the rise being influenced by education, there may be an added recent effect of screen time. The aim of this systematic review is to determine the association between screen time and the risk of developing (1) prevalent or incident myopia, or (2) the risk of myopia progression in children. Published manuscripts were identified in PubMed, ScienceDirect and the Cochrane Library, and citation lists were reviewed. Fifteen studies were included (nine cross-sectional and six cohort studies) with a total of 49789 children aged between 3 and 19years old. Seven studies found an association between screen time and myopia. The results showed mixed evidence with the more recent studies exposing a trend of association between hours spent by children using screens and myopia. Meta-analysis using a random-effects model was performed in five studies (n=20889) that reported odds ratio (OR). The I2 statistics was used to assess heterogeneity. A pooled OR of 1.02 (95% CI: 0.96-1.08; p=0.48) suggests that screen time is not associated with prevalent and incident myopia in this group of five studies. The results for screen time and myopia are mixed. Further studies with objective screen time measurements are necessary to assess evidence of an association between screen time and myopia.