Five-Year Progression of Refractive Errors and Incidence of Myopia in School-Aged Children in Western China

Large-scale study in Chengdu, China: The prevalence of myopia full-correction decreased with increasing myopia in adolescents

Myopia is an increasingly serious health issue among children and adolescents worldwide. This study investigated the situation related to myopia among students in Chengdu, a city in western China, and analyzed the prevalence of myopia spectacle wear and myopia full-correction and their influencing factors to understand the current status of myopia prevention. This school-based cross-sectional study investigated 1582 schools in seven districts of Chengdu City, China, enrolling a total of 417,337 students aged 6-18 years (elementary, middle, and high school) from 2020 to 2022. Examination items included uncorrected visual acuity (UCVA), slit lamp examination and non-cycloplegic autorefraction. Myopia was defined as non-cycloplegic SE ≤ -0.50 D + UCVA> 0 log MAR (age ≥6). The prevalence of myopia spectacle wear is defined as the number of people wearing glasses for myopia/the number of people with myopia (%) within the study population, and myopia full-correction is defined as normal vision after wearing glasses for myopia (≤0 log MAR for 6 years and above). With the support of the government, this programme is conducted 1-2 times a year. Statistical analyses are conducted to determine the association between myopia and various parameters. The average age of the entire survey population was 10.96 ± 3.5 years, and the overall prevalence of myopia was 48.7%, myopia spectacle wear was 65.7%, and myopia full-correction was 50.5%. With increasing age and educational levels, the prevalence of moderate to high myopia, the prevalence of myopia spectacle wear, and the prevalence of myopia full-correction all rise. The prevalence of mild myopia full-correction (46.5%) was higher than that for moderate myopia (47.1%) and even higher than that for high myopia (39.6%). The correct utilization rate of myopic spectacles was 33.17%, increasing with age and education levels, with the highest correct utilization rate of 40.7% among those with moderate myopia. The prevalence of myopia among children and adolescents in Chengdu is relatively low, and the prevalence of myopia spectacle wear and myopia full-correction need to be improved, and it was found that with the increase of myopia, the prevalence of myopia full-correction among adolescents decreased instead.

Verification of a nationwide population-based myopia growth chart in a large longitudinal cohort of 1155 Korean children

OBJECTIVE

To evaluate predictive value of the myopia growth chart based on population-based health survey data using longitudinal cohorts.

METHODS

Patients aged from 5 to 18 years and underwent two or more cycloplegic refraction (CR) exams with at least one year of interval were included. Percentile deviation was calculated by subtracting percentile at final exam from the percentile at initial exam based on the chart. Spherical equivalent (SE) deviation was calculated by SE at final CR subtracted from predicted SE based on initial CR using the chart.

RESULTS

2310 eyes from 1155 subjects were included. There were 1344 eyes (58.2%) categorized as inliers, where both initial and final CR were within the 2nd to 99th percentile. Mean percentile and SE deviations were + 11.0 ± 22.9 percentiles and -0.60 ± 1.33 diopters, each. Outliers, those except the inliers, were 966 eyes (41.8%). Most outliers (709 eyes, 73.4%) were outside the chart for both initial and final exam. The rest of the outliers (257 eyes, 26.2%) were within the 2 to 99 percentile range on the chart at least once, either at initial or final exams; most of those (202 eyes, 78.6%) progressed toward myopia more than predicted.

CONCLUSIONS

In our large cohorts, both inliers and outliers tended to progress toward more myopia than predicted from the chart. This suggests the chart predicts childhood myopia rather conservatively. The myopia growth chart may be useful as a screening tool in detecting children at high risk of developing high myopia.

Association between choriocapillaris perfusion and axial elongation in children using defocus incorporated multiple segments (DIMS) spectacle lenses

PURPOSE

To investigate choroidal and ocular biological variables that influence axial length (AL) elongation in children wearing defocused incorporated multiple segments (DIMS) spectacle lenses.

METHODS

This cohort study included 106 myopic children aged 7-14 years with a 1-year follow-up. Participants were divided into two groups according to the increase in AL in one year: rapid (>0.2 mm) and slow (≤0.2 mm) axial elongation groups. Cycloplegic autorefraction and AL were measured at baseline and after 6 and 12 months. The area of choriocapillaris flow voids (FVs) and choroidal thickness (ChT) at baseline were measured.

RESULTS

Univariate linear regression analysis showed that AL elongation were significantly associated with the FVs area (standardised β = 0.198, P < 0.05) and age (standardised β = -0.201, P < 0.05). Multiple linear regression showed that the FVs area, age, and average K reading were associated with AL elongation. Multiple logistic regression analyses showed that greater degrees of myopia and larger FVs areas were risk factors for rapid axial elongation, while older age, large pupil diameter and steeper cornea were protective factors. In estimating axial elongation, the FVs area alone demonstrated an area under the curve (AUC) of 0.672 (95% CI, 0.569-0.775, P < 0.01), and that of FVs area and other ocular variables was 0.788 (95% CI, 0.697-0.878, P < 0.001).

CONCLUSION

Larger choriocapillaris FVs area at baseline may help to predict axial elongation in myopic eyes. The association between FVs area and axial elongation should be taken into consideration in further myopic cohort studies.

Intraocular Pressure and Myopia Progression, Axial Length Elongation in Rural Chinese Children

SIGNIFICANCE

This study reported the relationship between intraocular pressure (IOP) and myopia progression, which helps to understand more comprehensively whether IOP can be an important reference factor to intervene in the progression of myopia.

PURPOSE

This study aimed to investigate the association between IOP and myopia progression as well as axial length elongation in rural Chinese children.

METHODS

A total of 598 (598 of 878 [68.1%]) children (6 to 17 years) from the baseline Handan Offspring Myopia Study who completed a 3.5-year follow-up vision examination were included. Ocular examinations at both visits included cycloplegic autorefraction, IOP, and axial length measurements.

RESULTS

Children with myopia had the highest baseline IOP of the three refractive groups (14.13 ± 1.31, 13.78 ± 1.71, and 13.59 ± 1.64 mmHg in myopes, emmetropes, and hyperopes, respectively, P = .002). However, IOPs showed no significant difference between eyes with or without newly developed myopia (13.63 ± 1.68 vs. 13.89 ± 1.68, P = .16), with or without faster myopia progression (13.75 ± 1.61 vs. 13.86 ± 1.63, P = .46), or with axial length elongation (13.80 ± 1.61 vs. 13.76 ± 1.64, P = .80). The multivariate regression analysis demonstrated that neither baseline refractive error ( β = -0.082, P = .13) nor baseline axial length ( β = -0.156, P = .08) was associated with baseline IOP.

CONCLUSIONS

Myopic eyes have slightly higher IOP compared with emmetropic and hyperopic eyes, although it was not clinically significant. However, IOP was not found to be associated with either myopia progression or axial length elongation in this cohort sample of rural Chinese children.

Comparison of myopia progression among Chinese schoolchildren before and during COVID-19 pandemic: a meta-analysis

AIM

To compare myopia progression in Chinese schoolchildren before and after the COVID-19 pandemic home confinement.

METHODS

This study was done through the data searched from PubMed, Embase, Cochrane Library, and Web of Science from January 2022 to March 2023 related to the COVID-19 pandemic home confinement and myopia progression among Chinese schoolchildren. Myopia progression was evaluated by the mean change of spherical equivalent refraction (SER) and axial length (AL) before and during the COVID-19 pandemic. Sex and regional differences in myopia progression among schoolchildren before and during the COVID-19 pandemic were also analyzed.

RESULTS

A total of eight eligible studies were included in this study. There was a significant difference in SER before and during home confinement during the COVID-19 pandemic (OR = 0.34; 95%CI = [0.23, 0.44]; Z = 6.39; P < 0.00001), but no significant difference in AL (OR = 0.16; 95%CI = [- 0.09, 0.41]; Z = 1.22, P = 0.22). There was a significant difference in SER between male and female groups during the COVID-19 home confinement (OR = 0.10; 95%CI = [0.00, 0.19]; Z = 1.98, P = 0.05). As for regional analysis, there was a significant difference in SER between urban and rural areas during the COVID-19 quarantine period (OR = -0.56; 95%CI = [- 0.88, - 0.25]; Z = 3.50, P = 0.0005).

CONCLUSIONS

Compared with the time before the COVID-19 home confinement, a higher rate of myopic progression among Chinese schoolchildren during the period of the COVID-19 pandemic was demonstrated.

Investigation of Choroidal Blood Flow and Thickness Changes Induced by Near Work in Young Adults

PURPOSE

This research aimed to determine the effects of near work on macular choroidal blood flow and thickness in young adults.

METHODS

A total of 109 participants (19-28 years old) were recruited from Capital Medical University in China. The participants spent 40 min reading a book text at a distance of 33 cm. Swept-source optical coherence tomography/optical coherence tomography angiography (SS-OCT/OCTA) was performed to measure the changes in choriocapillaris perfusion area (CCPA) and choroidal thickness (ChT) after 40 min of near work. The SS-OCT/OCTA data covered an area of 6 mm × 6 mm, which centered on the fovea.

RESULTS

The baseline ChT and CCPA before near work were negatively correlated with AL, while positively correlated with the magnitude of spherical equivalent (p < .001). Total CCPA decreased significantly by 6 mm × 6 mm macular area after near work compared to that before near work (24.26 ± 1.96 vs. 24.63 ± 1.61 mm2, p<.001). The macular ChT was lower after 40 min of reading than that before 40 min of reading, but no significant difference was observed (302.25 ± 77.69 vs. 304.92 ± 79.73 μm, p = .078). The extent of choroidal thinning was significantly positively correlated with the magnitude of CCPA reduction (p < .001). The decline in CCPA after near work was significantly positively correlated with axial length (AL; p < .001).

CONCLUSION

This study demonstrated that near work significantly decreased CCPA. The extent of CCPA reduction after near work was associated with higher severity of myopia and choroidal thinning. The baseline CCPA and ChT decreased gradually with AL.

Progression and incidence of myopia among schoolchildren in the post-COVID-19 pandemic period: a prospective cohort study in Shantou, China

OBJECTIVES

To determine the progression and incidence of myopia in Chinese schoolchildren in the post-COVID-19 pandemic period in Shantou, China.

DESIGN

Prospective cohort study.

SETTING

Shantou Myopia Study, China.

PARTICIPANTS

1-year follow-up data were available for 621 881 schoolchildren (301 999 females). Data on spherical equivalent refraction (SER) were collected.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were myopia progression and incidence. Myopia progression is defined as a change of SER towards the negative direction in the follow-up visit. Incidence is defined as the proportion of schoolchildren who were not myopic but developed myopia in the follow-up study. Age, sex and SER at baseline were evaluated as associated factors for myopia burden, which were defined as the secondary outcomes.

RESULTS

Mean progression of SER was -0.35±0.97 D for the population (ranging from -0.06 D at 18 years of age to -0.46 D at 11 years of age), with a rapid myopic progression for students at the age of 10-12 years (-0.50 D in girls and -0.44 D in boys). A myopic shift greater than -0.50 D/year occurred in 256 299 eyes (41.21%). Myopic progression in refraction was associated with the 10-12 years age groups (OR 1.42; 95% CI 1.39 to 1.45, p<0.001), female sex (OR 1.09; 95% CI 1.08 to 1.10, p<0.001) and higher refractive errors at baseline (OR>1.00, p<0.001). The annual incidence of myopia among schoolchildren was 24.85%, with an incidence of 26.69% in girls and 23.02% in boys.

CONCLUSIONS

Our study revealed an annual myopia progression of -0.35 D and an incidence of 24.85% among schoolchildren in the post-COVID-19 pandemic period. Myopia progressed rapidly at 10-12 years of age, with -0.50 D in girls and -0.44 D in boys. The incidence was higher for children aged 10-11 years and for girls.

Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter

PURPOSE

To compare changes in ocular aberrations in children wearing orthokeratology (ortho-k) lenses with a back optic zone diameter (BOZD) of 6 mm (6-MM group) or 5 mm (5-MM group) and their associations with axial elongation (AE) over two years.

METHODS

Seventy Chinese children, aged 6 to < 11 years, with myopia between - 4.00 to - 0.75 D, were randomly allocated to 5-MM and 6-MM groups. Ocular aberrations were measured, rescaled to a 4-mm pupil, and fitted with a 6th order Zernike expansion. Measurements, including axial length, were taken prior to commencing ortho-k treatment and then every six months over two years.

RESULTS

After two years, the 5-MM group displayed a smaller horizontal treatment zone (TZ) diameter (by 1.14 ± 0.11 mm, P < 0.001) and less AE (by 0.22 ± 0.07 mm, P = 0.002) compared with the 6-MM group. A greater increase in total root mean square (RMS) of higher-order aberrations (HOAs), primary spherical aberration (SA) ([Formula: see text], and coma were also observed in the 5-MM group at all follow-up visits. The horizontal TZ diameter was significantly associated with changes in RMS HOAs, SA (RMS, primary and secondary SA), and RMS coma. After controlling for baseline parameters, RMS HOAs, RMS SA, RMS coma, and primary ([Formula: see text] and secondary ([Formula: see text] SA were significantly associated with AE.

CONCLUSIONS

Ortho-k lenses with a smaller BOZD created a smaller horizontal TZ diameter and a significant increase in total HOAs, total SA, total coma, and primary SA and a decrease in secondary SA. Of these ocular aberrations, total HOAs, total SA, and primary SA were negatively correlated with AE over two years.

TRIAL REGISTRATION

ClinicalTrial.gov, NCT03191942. Registered 19 June 2017, https://clinicaltrials.gov/ct2/show/NCT03191942 .

Three-year change in refractive error and its risk factors: results from the Shahroud School Children Eye Cohort Study

OBJECTIVES

To determine spherical equivalent (SE) progression among children in the Shahroud School Children Eye Cohort Study.

METHODS

A prospective cohort study recruited children aged 6 to 12 years in 2015 (baseline) with a follow-up in 2018. Cycloplegic autorefraction and axial length (AL) measurements were included. SE progression over 3 years was analysed in non-myopic (SE ≥ + 0.76 D), pre-myopic (PM; SE between +0.75 D and -0.49 D), low myopic (LM; SE between -0.5 D and -5.99 D), and high myopic (HM; SE ≤ - 6 D) eyes. Age, sex, near work, outdoor time, living place, parental myopia, mother's education, and baseline SE were evaluated as risk factors for SE progression (≤ -0.50 D).

RESULTS

Data were available for 3989 children (7945 eyes). At baseline, 40.3% (n = 3205), 3.4% (n = 274) and 0.1% (n = 7) eyes had PM, LM and HM, respectively. At the 3-year follow-up, 40.5% (n = 3216), 7.5% (n = 599) and 0.2% (n = 15) eyes had PM, LM, and HM, respectively. SE progression in eyes with LM and HM was -1.08 ± 0.76 D and -1.60 ± 1.19 D, respectively. SE progression was associated with age at baseline (Odds Ratio [OR] = 1.14; 95% confidence interval [CI], 1.08-1.21), female sex (OR = 1.80; 95% CI: 1.48-2.18), near work (OR = 1.08; 95% CI: 1.02-1.14), parental myopia (OR = 1.20; 95% CI: 1.01-1.42) and baseline SE (OR = 2.28; 95% CI: 1.88-2.78).

CONCLUSION

A myopic shift was associated with older age, female sex, near work, parental myopia and greater myopic baseline SE. These results help identifying children at risk of progression that may benefit from treatment and lifestyle counselling.

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.

Epidemiological investigation of the status of myopia in children and adolescents in Fujian Province in 2020

PURPOSE

The 2020 epidemiological investigation of myopia in children and adolescents in Fujian Province' aimed to provide reference guidelines for the prevention and control of myopia. The purpose of the present study was to address shortfalls in the epidemiological survey of myopia in Fujian and provide a basis for government decision making.

STUDY DESIGN

A cross-sectional and epidemiological investigation METHODS: Based on their levels of economic development and other economic factors, three cities in Fujian Province (Fuzhou, Xiamen, Longyan) were chosen through cluster random sampling and epidemiological investigation. Final analysis included 41,906 cases. Examinations including visual acuity and mydriatic optometry were performed on all subjects.

RESULTS

The overall proportion of myopia was 63.35% in boys and 70.55% in girls living in Fujian in 2020. The proportions of myopia in Xiamen and Longyan were similar; both cities showed a higher proportion of myopic cases than Fuzhou. The proportion of girls with myopia was higher than boys. The proportion of primary and middle school students with myopia was higher in economically developed regions compared with underdeveloped regions. The proportion of urban students with myopia was higher than in suburban students. Analysis showed that the prevalence of myopia increased with age. Interestingly, the prevalence of myopia was higher in children born in June and August than in children born in other months.

CONCLUSION

Children and adolescents in Fujian have a high rate of myopia which increases as the school grade increases. The better the economic conditions are, the higher the myopic rate. In addition, the myopic rate is higher in girls in and students born in June and August. The government, schools, hospitals, and parents should be alerted to this issue and coordinate to control the risk of myopia exacerbation and improve eyesight conditions of students in Fujian Province.

Effects of behaviors and surrounding environment on myopia before and during the COVID-19 pandemic: a longitudinal analysis of children and adolescents in China

Aim

To investigate the relationship between related factors and visual acuity of Chinese school students before and during the COVID-19 pandemic.

Subject and methods

Chinese students from primary and secondary schools were included from the Chinese National Surveys on Students' Constitution and Health CNSSCH (2019). A total of 1496 participants completed follow-ups in June and December 2020, respectively. Generalized estimating equations were used to test the differences in visual environment. Logistic regression models were utilized to examine the roles of behaviors and surrounding environment changes associated with myopia before and during the pandemic.

Results

The prevalence of myopia was 47.7%, 55.6%, and 57.2% in baseline and two follow-ups, respectively. Significant differences existed for gender, learning level, and region (all P < 0.05). The proportion of new myopia and myopia torsion was the highest in the primary schools. Multivariate logistic regression analysis found that screen time ≥ 4h/d (OR = 2.717), poor eye habits (OR = 1.477), insufficient lighting for studying at night (OR = 1.779), desk or roof lamps only (OR = 1.388), and poor sleep quality (OR = 4.512) were the risk factors for myopia (all P < 0.05), and eye exercises (OR = 0.417), milk intake (OR = 0.758), and eggs intake (OR = 0.735) were the protective factors for myopia (all P < 0.05).

Conclusion

Prevalence of myopia increased among Chinese students before and during the COVID-19. It is necessary to pay more attention to the pupils' visual acuity, especially in primary school students, in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-023-01900-w.

Long-term myopia control effect and safety in children wearing DIMS spectacle lenses for 6 years

This study evaluated the long-term myopia control effect and safety in children wearing Defocus Incorporated Multiple Segments (DIMS) spectacle lenses. Participants who completed the 2-year RCT were followed for a total of 6 years; their cycloplegic refractions and axial length were measured. Group 1 (n = 36) wore DIMS spectacles for 6 years; Group 2 (n = 14) wore DIMS lens for the first 3.5 years and SV spectacles afterwards; Group 3 (n = 22) wore SV spectacles in the first 2 years and switched to DIMS; Group 4 (n = 18) wore SV spectacles in the first 2 years, switched to DIMS for 1.5 years and then SV spectacles again. Group 1 showed no significant differences in myopia progression (- 0.52 ± 0.66 vs. - 0.40 ± 0.72D) and axial elongation (0.32 ± 0.26 vs. 0.28 ± 0.28 mm, both p > 0.05) between the first and the later 3 years. In the last 2.5 years, DIMS lens groups (Groups 1 and 3) had less myopia progression and axial elongation than the single vision groups (Groups 2 and 4). There was no evidence of rebound after stopping the treatment. Post-wear visual functions in all groups were within norms. The results supported that DIMS lenses provided sustained myopia control without adverse effects over the 6-year study period.Trial registration: clinicaltrials.gov; NCT02206217.

Epidemiological Characteristics and Influencing Factors of Myopia Among Primary School Students in Southern China: A Longitudinal Study

Objectives: To study the epidemiological characteristics and influencing factors of myopia to provide a scientific basis for the prevention and control of myopia. Methods: 7,597 students studying in grades 1-3 were followed up. Eye examinations and questionnaire surveys were conducted annually from 2019 to 2021. The influencing factors of myopia were analyzed by logistic regression model. Results: The prevalence of myopia among students in grades 1-3 in 2019 was 23.4%, which increased to 41.9% and 51.9% after the 1-and 2-year follow-up, respectively. The incidence of myopia and change in the spherical equivalent refraction (SER) were higher in 2020 than in 2021. The 2-year cumulative incidences of myopia were 2.5%, 10.1%, 15.5%, 36.3%, and 54.1% in students with a baseline SER >+1.50D, +1.00D to +1.50D, +0.50D to +1.00D, 0.00D to +0.50D, and -0.50D to 0.00D, respectively. Outdoor activities, sex, age, baseline SER, parental myopia, sleep time, and digital device exposure were associated with myopia. Conclusion: The prevalence of myopia demonstrated a rapid increase; thus, healthy habits and outdoor activities should be promoted for the prevention and control of myopia.

The Efficacy of Defocus Incorporated Multiple Segments Lenses in Slowing Myopia Progression: Results from Diverse Clinical Circumstances

PURPOSE

Defocus incorporated multiple segments (DIMS) spectacle lenses were reported to slow myopia progression significantly in a randomized controlled trial (RCT). The study evaluated their effectiveness in clinical settings.

DESIGN

Retrospective study.

PARTICIPANTS

Patient records involving use of DIMS and single-vision (SV) spectacle lenses were collected from subsidiary hospitals of Aier Eye Hospital Group.

METHODS

The spherical equivalent (SE), determined by subjective refraction, was adopted to assess the myopia progression. The strategy of propensity score matching (PSM) was applied to match the confounding baseline characteristics between the 2 groups. The effectiveness was calculated based on the difference of myopia progression of these 2 approaches.

MAIN OUTCOME MEASURES

Change in SE.

RESULTS

Three thousand six hundred thirty-nine patients with DIMS and 6838 patients with SV spectacles were included. The age of the patients was 6 to 16 years (mean ± standard deviation: 11.02 ± 2.53 years). The baseline SE was between 0.00 and -10.00 diopters (D) (mean ± standard deviation: -2.78 ± 1.74 D). After the PSM, data on 2240 pairs with 1-year follow-up and on 735 pairs with 2-year follow-up were obtained. Significantly slower progression was seen in the DIMS group at both the 1-year (DIMS, -0.50 ± 0.43 D; SV, -0.77 ± 0.58 D; P < 0.001) and 2-year (DIMS, -0.88 ± 0.62 D; SV, -1.23 ± 0.76 D; P < 0.001) subdataset. In the 1-year subdataset, 40% and 19% showed myopia progression of no more than 0.25 D for the DIMS and SV groups, respectively (chi-square, 223.43; P < 0.001), whereas 9% and 22% showed myopia progression of more than 1.00 D for the DIMS and SV groups, respectively (chi-square, 163.38; P < 0.001). In the 2-year subdataset, 33% and 20% showed myopia progression of no more than 0.50 D for the DIMS and SV groups, respectively (chi-square, 31.15; P < 0.001), whereas 12% and 29% showed myopia progression of more than 1.50 D for the DIMS and SV groups (chi-square, 65.60; P < 0.001).

CONCLUSIONS

Although the magnitude was lower than that reported in the previous RCT, this large-scale study with diversity of the data sources confirmed the effectiveness of DIMS spectacles to slow myopia progression in clinical practice.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Trends of myopia development among primary and junior school students in the post-COVID-19 epidemic period

Purpose

To investigate the trends of myopia among primary and junior school students in the post-COVID-19 epidemic period.

Method

A prospective of cross-sectional study using spot photoscreenings in 123,538 children among primary and junior school students from 2019 to 2021 was conducted to evaluate the development of myopia in Xuzhou, China in the post-COVID-19 epidemic period. Equivalent refraction and the prevalence of myopia were recorded.

Results

The spherical equivalent refraction of myopia decreased across all grades except grade 1 (0.23 ± 0.56 D in 2019, 0.24 ± 0.63 D in 2020) from 2019 to 2020. However, refraction exhibited a hyperopic shift in 2021 compared to 2020 for grades 1-5 (no significant decreased for grade 4). The prevalence of myopia in all grades increased in 2020 compared to 2019, and the most dramatic changes were observed from grades 2-5 and grades 7-8 (P < 0.05). The changes in myopia prevalence in grades 1-4 were mild, and the reduction in myopia for Grade 5 is significant from 2020 to 2021. Nevertheless, students in grades 6 and 9 exhibited the greatest growth in myopia prevalence (P < 0.01). All grades had higher myopia prevalence in 2021 compared with 2019, except grade 1 (P = 0.25). The prevalence of myopia in girls was higher compared with boys, and the urban myopia prevalence was higher than in rural areas over the 3 years except in 2019 (P = 0.18).

Conclusions

The prevalence of myopia increased during the COVID-19 epidemic. However, the spherical equivalent refraction of lower grade children drifted to hyperopia and the trends of myopia development remained stable in the post-COVID-19 epidemic period. We should be more concerned about the prevalence of myopia in graduating for the primary or junior grades in the future.

A comparative study of the prevalence of myopia and behavioral changes in primary school students

Objective

To analyze the changes in the prevalence of myopia and its relation to ocular biological parameters, and behaviors among primary school students in China, and understand the prevention and control of myopia.

Methods

Cross-sectional surveys were performed on 7–9-year-old children in the yrs. 2012 and 2019. In addition, spherical equivalent refraction (SER), axial length (AL), and AL/corneal radius ratio (AL/CR ratio) were collected without cycloplegia. Participants completed detailed questionnaires on behavior related to myopia.

Results

Data was collected on 623 children (8.02 ± 0.57 years old) in 2012 and 536 students in 2019 (8.09 ± 0.65 years old). The prevalence of myopia was 37.7% in 2012 and 39.9% in 2019. The SER was -0.25 (0.92) D in 2012 and -0.25 (1.25) in 2019. There was no statistical difference in the prevalence of myopia and SER over the 7 years (all P > 0.05). In 2019, the prevalence of myopia among girls demonstrated an increasing trend (33.8% vs. 37.8%), but there was no statistical difference (P > 0.05). The mean AL and AL/CR ratio of boys were decreasing (all P < 0.05). The proportion of children reading more than 2 h and using digital devices for more than 2 h per day after their classes in the 2019 group both decreased (all P < 0.05). However, the proportion of activities performed outdoors for more than 2 h./day decreased significantly (P = 0.001).

Conclusion

Compared with 2012, the prevalence of myopia in primary school students in 2019 was under control, which may be related to the improvement of children's near-work behavior, but there was the problem of insufficient outdoor activity time. In terms of ocular biological parameters, the risk of myopia for boys in 2019 was lower.

The Prevalence and Progression of Myopia in Elementary School Students in Shanxi Province, China During the COVID-19 Pandemic

PURPOSE

To investigate the prevalence of myopia and the risk factors associated with its progression in elementary school students during the COVID-19 pandemic in Shanxi Province, China.

METHODS

The investigation included 960 students spanning first to sixth grade from six elementary schools in Shanxi Province, China. All participants received non-cycloplegic refraction and vision tests in December of 2019 (before the COVID-19 pandemic) and in June of 2020 (after classes resumed). Information concerning the students' eye-use behaviors, physical activities, diet and sleep during the pandemic was collected using a questionnaire survey. A total of 913 students (457 males) completed all tests and the questionnaire.

RESULTS

The overall prevalence rate of myopia was 16.6% in December of 2019, and it increased with age. There was no gender difference in the prevalence of myopia (χ² = 3.210, P = .073), but females exhibited a lower average spherical equivalent (SE) (P = .026). When the classes were resumed 6 months later, the overall prevalence rate of myopia was found to be 39.4%, which was significantly higher than it before the pandemic (χ² = 117.425, P < .001). The average SE of the participants was -0.95D, which was significantly lower than the average SE (-0.43D) before the pandemic (P < .001). SE variation (ΔSE) in grade 6 was significantly higher than that in grade 1. No significant difference in ΔSE was found between males and females. Analyses of ordinary least squares (OLS)-estimated linear, natural logarithmic and quadratic functions revealed that the progression of myopia during the COVID-19 pandemic was significantly correlated with screen time, types of electronic devices, the amount of sleep, age, and the number of parents with myopia.

CONCLUSIONS

The prevalence rate and progression of myopia among elementary school students in Shanxi Province increased significantly during the COVID-19 pandemic, which was likely related to China's home-based online learning programs. Therefore, it is necessary to optimize the educational programs for elementary school students when they study at home. We recommend increased time for outdoor activities and limiting screen time.

Effect of Time Outdoors and Near-viewing Time on Myopia Progression in 9- to 11-year-old Children in Chongqing

SIGNIFICANCE

We used an Akeso device to record the visual behavior of children with myopia in two learning modes. We found that online class mode may increase near-viewing time and reduce outdoor time compared with the traditional school mode and may be responsible for accelerating myopia progression.

PURPOSE

We aimed to explore the effects of visual behavior in different learning mode on myopia progression among children 9-11 years old.

METHODS

Forty-nine children were included and requested to use a wearable device to objectively record visual behavior in real time from November 2019 to November 2020, participants took online classes from mid-February to early May 2020 during this period. Data (including glasses wearing time, outdoor time, and near-viewing time) were collected over two 14-day periods, which included the online class learning mode (March 2-15, 2020) and traditional school mode (May 20 to June 2, 2020). Spherical equivalent refraction and axial length were obtained at baseline, at 6-month intervals, and 1 year later.

RESULTS

Outdoor time during online class mode (median 9.5 min, IQR:0.75-48) was significantly lower than during school mode (median 29 min, IQR:11.50-50; P < .001). The mean ± standard deviation of near-viewing time was significantly different between online class mode (396.58 ± 114.41 min) and school mode (376.52 ± 93.99 min) (P = .007, F = 19.56). In comparison with the baseline examination (-2.33 ± 0.81 Diopter), mean spherical equivalent refraction in oculus dexter corresponding to the 6-month examination was decreased (-2.94 ± 0.83 D, P = .001), indicating a significant increase in myopia during online class mode.

CONCLUSIONS

This study provides evidence of the association of learning mode and myopia progression, accelerated progression of myopia in online class mode may be related to increase near time and decreased time spent in outdoor activities.

Manual and software-based measurements of treatment zone parameters and characteristics in children with slow and fast axial elongation in orthokeratology

PURPOSE

To compare the treatment zone (TZ) measurements obtained using manual and software-based methods in orthokeratology (ortho-k) subjects and explore the TZ characteristics of children with slow and fast axial elongation after ortho-k.

METHODS

Data from 69 subjects (aged 7 to <13 years old), who participated in three 24-month longitudinal orthokeratology studies, showing fast (>0.27 mm, n = 38) and slow (<0.09 mm, n = 31) axial elongation, were retrieved. The TZ after ortho-k was defined as the central flattened area enclosed by points with no refractive power change. TZ parameters, including decentration, size, width of the peripheral steepened zone (PSZ), central and peripheral refractive power changes and peripheral rate of power change, were determined manually and using python-based software. TZ parameters were compared between measurement methods and between groups.

RESULTS

Almost all TZ parameters measured manually and with the aid of software were significantly different (p < 0.05). Differences in decentration, size and the PSZ width were not clinically significant, but differences (0.45 to 0.92 D) in refractive power change in the PSZ were significant, although intraclass coefficients (0.95 to 0.98) indicated excellent agreement between methods. Significantly greater TZ decentration, smaller TZ size and greater inferior rate of power change (relative to the TZ centre) were observed in slow progressors using both methods, suggesting a potential role of TZ in regulating myopia progression in ortho-k.

CONCLUSION

TZ measurements using manual and software-based methods differed significantly and cannot be used interchangeably. The combination of TZ decentration, TZ size and peripheral rate of power change may affect myopia control effect in ortho-k.

The change of myopic prevalence in children and adolescents before and after COVID-19 pandemic in Suqian, China

Purpose

The aim of this study was to investigate the change of myopic prevalence in students with different demographic characteristics before and after the COVID-19 pandemic in Suqian, China.

Methods

A retrospective, cross-sectional study was conducted. Student data from 52 schools in 2019 and 2020 were collected from the electronic medical records database through cluster sampling. Ophthalmic examinations were conducted on students from September to December in 2019 and 2020. Measurements of uncorrected visual acuity (UCVA) and noncycloplegic autorefraction were included to obtain the spherical equivalent refraction (SER) and prevalence of myopia. The difference in the rate of myopia and SER of students ages 6 to 18 with various demographic characteristics was compared between the two years.

Results

Records from 118,479 students in 2019 and the 121,881 students in 2020 were obtained. In 2019 and 2020, the prevalence of overall myopia increased from 43.1% to 48.9% (5.8 percentage point), and a substantial shift in myopic rate occurred in grades 4 to 6 (6.9 percentage point). The change in the prevalence of myopia in girls (5.9 percentage point) was approximately equal to that in boys (5.8 percentage point) and it was more common in rural students (5.9 percentage point) than in urban students (5.1 percentage point). The prevalence of low myopia increased more in children, and the prevalence of moderate myopia increased more in adolescents. The mean spherical equivalent refraction (SER) (-1.34±2.03 D) was lower in 2020 than in 2019 (-1.16±1.92 D), while SER decreased mainly at ages 7 to 15. The SER presented myopic status at the age of 9 (-0.55±1.26 D in 2019, -0.71±1.42 D in 2020), and attained moderate myopia at the age of 15 (-3.06±2.41 D in 2019, -3.22±2.40 D in 2020).

Conclusions

After the COVID-19 pandemic, myopia increased in this population with variable rates of increase in different demographic groups. The change of myopia in children was comparatively greater than that in adolescents. Therefore, we should take measures to prevent and control the development of myopia after the COVID-19 pandemic, especially for younger students.

Trends in Myopia Development Among Primary and Secondary School Students During the COVID-19 Pandemic: A Large-Scale Cross-Sectional Study

Objectives

To evaluate myopia development among primary and secondary school students during the coronavirus 2019 (COVID-19) pandemic.

Methods

A cross-sectional study was conducted to evaluate the development of myopia among students in Shenzhen, China during the COVID-19 outbreak.

Results

The study included 1,472,957 and 1,573,824 students in 2019 and 2020, respectively. The prevalence of myopia was 46.9 and 50.5% in 2019 and 2020, respectively. The prevalence of myopia among students in the former Shenzhen Special Economic Zone (SEZ) was higher than that in areas outside the former Shenzhen SEZ (2019: 47.0 vs. 43.7%; 2020: 50.5 vs. 47.3%). The prevalence of myopia among girls was higher than that among boys (2019: 50.4 vs. 44.0%; 2020: 54.0 vs. 47.6%). The 50th percentile (P50) of spherical equivalent refraction (SER) in the right eye among girls was lower than that in boys. The prevalence of myopia continued to increase as the grade increased, with the greatest annual increase observed in Grades 2–5 (3.4–3.9%). The P50 of SER in the right eye of students decreased as the grade increased.

Conclusions

The prevalence of myopia among students increased during the COVID-19 pandemic, especially in primary school Grades 2–5.

Longitudinal analysis of 5-year refractive changes in a large Japanese population

Refractive changes are reportedly affected by age, sex, and current refractive error. To clarify the pattern of refractive changes in a Japanese population, we conducted a 5-year follow-up longitudinal analysis of spherical equivalent (SE) refractive changes with stratification by sex, age, and SE in 593,273 eyes from Japanese individuals ages 3–91 years. The 5-year SE change with myopic shift dramatically increased over time after age 4 years, and the largest change was observed in both males and females who were age 8 years at baseline [males: − 2.654 ± 0.048 diopters (D); females: − 3.110 ± 0.038 D]. During school age, the 5-year myopic change was greater in females than in males, and emmetropic and low-to-moderate myopic eyes underwent larger myopic changes than hyperopic and high-to-severe myopic eyes. After the peak at age 8 years, the 5-year myopic change gradually declined with age and fell below − 0.25 D at age 27 in males and age 26 years in females. The 5-year SE changes transitioned from a myopic to a hyperopic shift at age 51 in both sexes, and hyperopization advanced more quickly in hyperopic eyes. Our findings highlight the importance of myopia prevention in school-aged children.

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

CLINICAL RELEVANCE

Knowledge of interactions between genetic variants and near-work activities at the onset of myopia can facilitate health education regarding myopia.

BACKGROUND

To investigate the interactions between genetic variants (PDE10A, AREG and GABRR1) and near-work activities in the onset of myopia in southeastern Chinese school children.

METHODS

A 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.

RESULTS

The 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; P_interaction = 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; P_interaction = 0.043).

CONCLUSIONS

The 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.

Annual Incidences and Progressions of Myopia and High Myopia in Chinese Schoolchildren Based on a 5-Year Cohort Study

Purpose

To determine the annual incidences and rates of progression of myopia and high myopia in Chinese schoolchildren from grade 1 to grade 6 and explore the possible cause-specific risk factors for myopia.

Methods

From 11 randomly selected primary schools in Anyang city, central China, 2835 grade 1 students were examined with annual follow ups for 5 years. Students were invited to undergo a comprehensive examination, including cycloplegic autorefraction, ocular biometry, and standardized questionnaires.

Results

The mean spherical equivalent refraction decreased substantially from +0.94 ± 1.03 diopter (D) in grade 1 to −1.37 ± 2.08 D in grade 6, with rapid annual myopic shifts, especially for students in grades 3 through 6 (−0.51 to −0.59 D). The prevalence of myopia increased substantially, with the yearly incidence of myopia increasing from 7.8% in grade 1 and 2 to 25.3% in grades 5 and 6, and the incidence of high myopia increased from 0.1% to 1.0%. The 5-year incidence of myopia was lowest among children who has a baseline spherical equivalent refraction of greater than +2.00 D (4.4%), and increased to nearly 92.0% among children whose baseline spherical equivalent refraction was 0.00 to −0.50 D. The incidence of myopia was higher in children who had less hyperopic baseline refraction, two myopic parents, longer axial length, deeper anterior chamber, higher axial length–corneal radius of curvature ratio, and thinner lenses.

Conclusions

Both the annual incidence and progression rates of myopia and high myopia were high in Chinese schoolchildren, especially after grade 3. Hyperopic refraction of children should be monitored before primary school as hyperopia reserve to prevent the onset of myopia and high myopia.

Progression of myopia in teenagers and adults: a nationwide longitudinal study of a prevalent cohort

BACKGROUND

The prevalence of myopia is increasing worldwide. The purpose of this study was to evaluate the progression of myopia in teenagers and adults in France.

METHODS

This nationwide prospective study followed 630 487 myopic adults and teenagers (mean age 43.4 years±18.2, 59.8% of women) between January 2013 and January 2019. Myopia and high myopia were defined as a spherical equivalent less than or equal to -0.50 and -6.00 diopters (D), respectively. Demographic data were collected at first visit and refractive characteristics were collected at each visit. Analysis of short-term progression (first 12 to 26 months postbaseline) was modelled using analysis of variance (ANOVA). Progression of myopia was stratified according to age, gender and spherical equivalent at first visit.

RESULTS

Higher proportions of progressors were observed in the youngest age groups: 14-15 (18.2 %) and 16-17 years old (13.9 %). In multivariate analysis, after adjustment for over age, spherical equivalent and gender, the mean short-term progression decreased from -0.36 D in the 14-15 years age group to -0.13 D in the 28-29 years age group. Young age and higher myopia at baseline together were strongly associated with the risk of developing high myopia, the 5-year cumulative risk being 76% for youngest teenager with higher myopia status at baseline.

CONCLUSION

In this large cohort of myopic teenagers and adults, myopia progression was reported in 18.2% and 13.9% of the 14-15 and 16-17 age groups, respectively. The risk to develop high myopia was higher for younger individuals with higher myopia at baseline examination.

COVID-19 Home Quarantine Accelerated the Progression of Myopia in Children Aged 7 to 12 Years in China

Purpose

To investigate the effect of home quarantine during the COVID-19 pandemic on myopia progression in children and its associated factors.

Methods

Myopic children aged 7 to 12 years with regular follow-up visits every half a year from April 2019 to May 2020 were included. Cycloplegic refraction was measured at baseline and at two follow-up visits. The first follow-up visit (visit 1) was conducted before the COVID-19 home quarantine, whereas the second (visit 2) was four months after the home quarantine. Myopia progression at visits 1 and 2 were compared. Factors associated with changes in myopia progression were tested with a multiple regression analysis.

Results

In total, 201 myopic children were enrolled. There was a significantly greater change in spherical equivalent at visit 2 (−0.98 ± 0.52 D) than at visit 1 (−0.39 ± 0.58 D; P < 0.001). Students were reported to have spent more time on digital devices for online learning (P < 0.001) and less time on outdoor activities (P < 0.001) at visit 2 than at visit 1. Children using television and projectors had significantly less myopic shift than those using tablets and mobile phones (P < 0.001). More time spent on digital screens (β = 0.211, P < 0.001), but not less time on outdoor activities (β = −0.106, P = 0.110), was associated with greater myopia progression at visit 2.

Conclusions

Changes in behavior and myopic progression were found during the COVID-19 home quarantine. Myopic progression was associated with digital screen use for online learning, but not time spent on outdoor activities. The projector and television could be better choices for online learning.

Prediction of myopia onset with refractive error measured using non-cycloplegic subjective refraction: the WEPrOM Study

Background/aims

To evaluate the predictive performance of various predictors, including non-cycloplegic refractive error, for risk of myopia onset under pragmatic settings.

Methods

The Wenzhou Medical University Essilor Progression and Onset of Myopia Study is a prospective cohort study of schoolchildren aged 6–10 years from two elementary schools in Wenzhou, China. Non-cycloplegic refraction, ocular biometry and accommodation measurements were performed. Myopia was defined as spherical equivalent (SE) ≤−0.5 diopter (D). ORs using multivariable logistic regression were determined. Area under the curve (AUC) evaluation for predictors was performed.

Results

Schoolchildren who attended both baseline and 2-year follow-up were analysed (N=1022). Of 830 non-myopic children at baseline, the 2-year incidence of myopia was 27.6% (95% CI, 24.2% to 31.3%). Female gender (OR=2.2), more advanced study grades (OR=1.5), less hyperopic SE (OR=11.5 per D), longer axial length (AL; OR=2.3 per mm), worse presenting visual acuity (OR=2.3 per decimal), longer near work time (OR=1.1 per hour/day) and lower magnitude of positive relative accommodation (PRA; OR=1.4 per D) were associated with myopia onset. PRA (AUC=0.66), SE (AUC=0.64) and AL (AUC=0.62) had the highest AUC values. The combination of age, gender, parental myopia, SE, AL and PRA achieved an AUC of 0.74.

Conclusion

Approximately one in four schoolchildren had myopia onset over a 2-year period. The predictors of myopia onset include lower magnitude of PRA, less hyperopic SE, longer AL and female gender. Of these, non-cycloplegic SE and PRA were the top single predictors, which can facilitate risk profiling for myopia onset.

Refractive errors and visual impairment among children and adolescents in southernmost China

Background

Refractive errors and visual impairment in southernmost China have not been reported previously. We aim to investigate and determine the age-specific prevalence of myopia, hyperopia, astigmatism, and visual impairment based on a large population cross-sectional study in Hainan area of southernmost tropical province in China.

Methods

A population-based sample of 31,524 children aged 615years from Hainan was assessed. Non-cycloplegic autorefraction and visual acuity (VA) analyses were performed on all participants and a subgroup of participants undergoing cycloplegia.

Results

Of all participants, 23.0% presented uncorrected VA (UCVA) was worse than 20/40 in worse eye, 6.0% presented mild presenting visual acuity impairment (PVAI), 7.0% presented moderate PVAI, 0.2% presented severe PVAI in the better eye, and 46.9% presented abnormal UCVA [worse than 20/25 (6,<8years old) and worse than 20/20 (8years and older)] at least in one eye. The overall prevalence of myopia [spherical equivalent (SE)0.50 D] and high myopia (SE6.00 D) were 46.0%, 1.0% respectively. Hyperopia [SE+1.00 D (7years old) and SE+2.00 D (6,<7years old)] and significant hyperopia (SE+3.00 D) were 4.2 and 0.6%, respectively. Astigmatism [cylinder1.00 D (7years old) and1.75 D (6,<7years old)] was found in 31.9%.

Conclusions

Myopia was the most common refractive error in southernmost province in China (Hainan). Its prevalence increased with age, while hyperopia prevalence showed a decreasing trend. However, myopia, especially high myopia prevalence was much lower than in other urban regions across China.

Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.

Trends in research related to high myopia from 2010 to 2019: a bibliometric and knowledge mapping analysis

AIM

To evaluate the global trends in and explore hotspots of high myopia (HM) research.

METHODS

This bibliometric analysis was used to reveal the publication trends in HM research field based on the Web of Science Core Collection (WoSCC). VOSviewer version 1.6.13 software was used to analyze the data and construct a knowledge map including the yearly publication number, journals, countries, international collaborations, authors, research hotspots, and intellectual base in HM.

RESULTS

The search engine found 3544 peer-reviewed publications on HM between 2010 and 2019, and the yearly research output substantially elevated over the past decade. China is the top publishing country, and Sun Yat-sen University was the most active academic institution. Jonas JB is the top publishing scientist, and Investigative Ophthalmology and Visual Science (IOVS) was the most productive journal. The highest cited references mainly focused on epidemiology and management. The keywords formed 6 clusters: 1) refractive surgery; 2) etiology and clinical characteristics; 3) the mechanism of eye growth; 4) management for myopic maculopathy; 5) vitrectomy surgical treatment; 6) myopia-associated glaucoma-like optic neuropathy.

CONCLUSION

The evaluation of development trends based on the data extracted from WoSCC can provide valuable information and guidance for ophthalmologists and public health researchers to improve management procedures in HM field.

PREVALENCE AND TIME TRENDS OF MYOPIA IN CHILDREN AND ADOLESCENTS IN CHINA: A Systemic Review and Meta-Analysis

PURPOSE

To estimate prevalence, associated factors, and time trends of myopia in Chinese children and adolescents.

METHODS

We searched PubMed, EMBASE, and Web of Science for studies examining the prevalence of myopia in children and adolescents aged 3 years to 19 years in China before October 2018. We pooled the prevalence and associated factors for myopia and estimated time trends.

RESULTS

In 22 eligible studies including 192,569 individuals, the pooled prevalence (95% confidence interval [CI]) of myopia and high myopia in the study period from 1998 to 2016 was 37.7% (95% CI: 23.5-52.0%) and 3.1% (95% CI: 1.2-5.0%), respectively, with higher odds for girls than boys (myopia: odds ratio: 1.29; 95% CI: 1.14-1.46; P < 0.001; high myopia: odds ratio: 1.37; 95% CI: 1.05-1.78; P = 0.02) and with higher prevalences for urban areas than rural regions (myopia: 48.8% [95% CI: 32.3-65.3] vs. 31.9% [95% CI: 20.4-43.3; P < 0.001]). The pooled prevalence of myopia and high myopia increased from 4.7% (95% CI: 2.5-6.9) and 0.2% (95% CI: 0.0-0.5), respectively, in <7-years-olds to 56.2% (95% CI: 29.8-82.5) and 15.1% (95% CI: 6.4-23.8), respectively, in 16- to 18-year-olds. Myopic refractive error increased with older age (P < 0.001), female gender (P < 0.001), and study year (P = 0.003). Studies performed after 2013 showed a prevalence of myopia and high myopia in the 16- to 18-year-olds of 84.8% (95% CI: 84.4-85.2%) and 19.3% (95% CI: 18.6-20.2%), respectively. Assuming a further linear relationship with the study year, myopia prevalence in 2050 among children and adolescents aged 3 years to 19 years would be estimated to be about 84%.

CONCLUSION

The marked rise in high myopia prevalence among adolescents in China may be of importance for high myopia as risk factor for irreversible vision loss in Chinese adults in the future.

TuYou-County Pediatric Eye (TYPE) study, design issues, baseline demographic characteristics, and implications: Report number 1

To report the rationale, design, and baseline demographic characteristics of TuYou-County Pediatric Eye study, which mainly aimed to determine the retinal microvascular changes with optical coherence tomography angiography (OCTA) and its association with eye abnormalities in school aged children and adolescents at suburban location in Northern China.TuYou-County Pediatric Eye study was a school-based survey conducted in TuYou-County. Multi-ethnic (Mongol, Han, and Hui) participants will be followed up for 5 years. Standardized ophthalmological examinations include visual acuity, ocular biometry, retinal photography, and OCTA. A questionnaire survey was conducted to collect variables regarding to eye disease such as parental history of eye diseases, near work, outdoor activities, living and eating habits, etc.After sampling, 687 participants were eligible for investigation, and 20 students did not attend the investigation, living 667 (response rate, 97.1%) students completed questionnaires and all ocular examinations. The average age of all participants was 14.9 ± 5.11.TYPE study is the first large-scale school-based multi-ethnic survey in suburban site of Northern China. Continuous identification of retinal microvascular changes with eye diseases will provide new insights into the control related diseases in school-age children and adolescents.

Progression of myopia in children and teenagers: a nationwide longitudinal study

Background

Data on myopia prevalence and progression in European children are sparse. The aim of this work was to evaluate the progression of myopia in children and teenagers in a large prospective study.

Methods

A prospective study involving a nationwide cohort. Myopia was defined as a spherical equivalent (SE) of ≤ –0.50 diopters (D). Data on refractive error, gender and age were collected in 696 optical centres in France between 2013 and 2019, including 136 333 children (4–17 years old) in the analysis.

Progression of myopia was assessed between the first visit and the last visit over up to 6.5 years.

Results

Mean age was 11.3±3.8 years (55.0% of female). The proportion of children progressing more than –0.50 D per year was higher in age groups 7–9 years and 10–12 years and in children with SE ≤ –4.00 D at first visit, representing 33.1%, 29.4% and 30.0% of these groups, respectively. In multivariate analysis, progression during the first 11–24 months was higher in the 7–9 and 10–12 age groups (–0.43 D and –0.42 D, respectively), for higher SE at baseline (at least –0.33 D for SE ≤ –1 D) and for girls (–0.35 D).

Conclusion

This is the first French epidemiological study to investigate myopia progression in a large-scale cohort of children. Sex, age groups and myopia severity are associated with differing rates of progression.

Difference of refractive status before and after cycloplegic refraction: the Lhasa Childhood Eye Study

PURPOSE

To compare the differences between cycloplegic and noncycloplegic refraction as well as associated factors in grade one students of primary schools, and explore the effectiveness of noncycloplegic refraction for refractive error screening.

STUDY DESIGN

Cross-sectional study.

METHODS

A school-based study of 1856 students was conducted in Lhasa, Tibetan Plateau, China. Cycloplegia was achieved with two drops of 1% cyclopentolate and 1 drop of Mydrin P at a 5-min interval. Autorefraction was performed under both cycloplegic and noncycloplegic conditions. Bland-Altman analysis, receiver operating characteristic curve analysis, univariate and multiple linear regression models were used for analysis.

RESULTS

Of the 1856 children enrolled, 1830 (98.60%) completed all procedures. The average age was 6.83 ± 0.46 years. 965 (52.73%) children were boys and 1737 (94.92%) were Tibetan. Overall, there was a significant difference between cycloplegic and noncycloplegic SE of 0.90 ± 0.76D (P < 0.001). However, the intra-class coefficient correlation (ICC) for cylinder between these two methods was high (ICC = 0.941, 95% CI, 0.935-0.946). Larger differences between cycloplegic and noncycloplegic SE were associated with hyperopic RE and higher cylindrical value (P < 0.001). The prevalence of myopia, emmetropia and hyperopia with and without cycloplegia was (3.93% vs 14.59%), (9.95% vs 45.8%) and (86.21% vs 39.56%), respectively. Myopia, emmetropia and hyperopia based on noncycloplegic refraction was defined as SE ≤ - 0.625D, - 0.625 < SE ≤ 0D, and SE > 0D, respectively.

CONCLUSIONS

Lack of cycloplegia leads to underestimation of hyperopia, with overestimation of myopia and emmetropia. Larger hyperopic refraction exhibited greater difference between cycloplegic and noncycloplegic refraction.

Myopia progression from wearing first glasses to adult age: the DREAM Study

Purpose

Data on myopia progression during its entire course are scarce. The aim of this study is to investigate myopia progression in Europeans as a function of age and degree of myopia from first prescription to final refractive error.

Methods

The Drentse Refractive Error and Myopia Study assessed data from a branch of opticians in the Netherlands from 1985 onwards in a retrospective study. First pair of glasses prescribed was defined as a spherical equivalent of refraction (SER) ≤−0.5 D to ≥−3.0 D. Subjects with prescriptions at an interval of at least 1 year were included in the analysis.

Results

A total of 2555 persons (57.3% female) met the inclusion criteria. Those with first prescription before the age of 10 years showed the strongest progression (−0.50 D; IQR: −0.75 to −0.19) and a significantly (p<0.001) more negative median final SER (−4.48 D; IQR: −5.37 to −3.42). All children who developed SER ≤−3 D at 10 years were highly myopic (SER ≤−6D) as adults, children who had SER between −1.5 D and −3 D at 10 years had 46.0% risk of high myopia, and children with SER between −0.5 D and −1.5 D had 32.6% risk of high myopia. Myopia progression diminished with age; all refractive categories stabilised after age 15 years except for SER ≤−5 D who progressed up to −0.25 D annually until age 21 years.

Conclusion

Our trajectories of the natural course of myopia progression may serve as a guide for myopia management in European children. SER at 10 years is an important prognostic indicator and will help determine treatment intensity.

Refractive change and incidence of myopia among rural Chinese children: the Handan Offspring Myopia Study

PURPOSE

To assess the refractive change and incidence of myopia, as well as their risk factors, among Chinese rural children aged 6-17 years.

METHODS

Children who completed the baseline vision examination of the Handan Offspring Myopia Study were re-examined, including both cycloplegic and non-cyloplegic autorefraction, with a mean follow-up time of 42.4±1.47 months.

RESULTS

A total of 601 children (68.5%) who completed both baseline and the follow-up examinations were enrolled. The cumulative refractive change and axial length change were -0.53±1.03 diopter and 0.39±0.46 mm (-0.15 diopter/year and 0.11 mm/year), respectively. A hundred and five out of the 469 non-myopic children at baseline become myopic at the follow-up, yielding a cumulative myopia incidence of 22.4% (95% CI: 18.6% to 26.2%), or annual myopia incidence of 6.3%. After adjustment, younger age (β=0.08, p<0.001), more myopic baseline refraction (β=0.31, p<0.001), larger difference between cycloplegic and non-cycloplegic refraction (β=-0.20, p=0.007) and more myopic paternal refraction (β=0.09, p=0.007) were found to be associated with more rapid myopic refractive change. More myopic baseline refraction (relative risk (RR), 95% CI: 0.19, 0.13-0.28, p<0.001) and more myopic paternal refraction (RR, 95% CI: 0.92, 0.84-1.00, p=0.039) were also associated with myopia incidence.

CONCLUSION

Relatively low myopic refractive change and myopia incidence were found in this study cohort. Children's refraction and paternal refraction were associated with both myopic refractive change and myopia incidence. Such information will be helpful for further comparisons in other rural versus urban areas of China, and other countries.

Myopic retinal changes screening: comparison of sensitivity and specificity among 15 combinations of ultrawide field scanning laser ophthalmoscopy images

AIMS

To investigate the evaluation indices (diagnostic test accuracy and agreement) of 15 combinations of ultrawide field scanning laser ophthalmoscopy (UWF SLO) images in myopic retinal changes (MRC) screening to determine the combination of imaging that yields the highest evaluation indices in screening MRC.

METHODS

This is a retrospective study of UWF SLO images obtained from myopes and were analyzed by two retinal specialists independently. 5-field UWF SLO images that included the posterior (B), superior (S), inferior (I), nasal (N) and temporal (T) regions were obtained for analysis and its results used as a reference standard. The evaluation indices of different combinations comprising of one to four fields of the retina were compared to determine the abilities of each combinations screen for MRC.

RESULTS

UWF SLO images obtained from 823 myopic patients (1646 eyes) were included for the study. Sensitivities ranged from 50.0% to 98.9% (95% confidence interval (CI), 43.8-99.7%); the combinations of B+S+I (97.3%; 95% CI, 94.4-98.8%), B+T+S+I (98.5%; 95% CI, 95.9-99.5%), and B+S+N+I (98.9%; 95% CI, 96.4-99.7%) ranked highest. Furthermore, the combinations of B+S+I, B+T+S+I and B+S+N+I also revealed the highest accuracy (97.7%; 95% CI, 95.1-100.0%, 98.6%; 95% CI, 96.7-100.0%, 98.8%; 95% CI, 96.9-100.0%) and agreement (Kappa = 0.968, 0.980 and 0.980). For the various combinations, specificities were all higher than 99.5% (95% CI, 99.3-100.0%).

CONCLUSION

In our study, screening combinations of B+S+I, B+T+S+I and B+S+N+I stand out with high-performing optimal evaluation indices. However, when time is limited, B+S+I may be more applicable in primary screening of MRC.

Association between time spent outdoors and myopia among junior high school students: A 3-wave panel study in China

This study sought to investigate the recent incidence rate of myopia in Chinese junior high school students and analyze the effect of time spent outdoors on myopia, in addition to facilitating the prevention and control of myopia among students.This study was derived from a national panel study, the China Education Panel Survey. We conducted three rounds of follow-up visits among 10,279 seventh grade students from 112 middle schools in 20 provinces in 2013. In total, 3571 students were selected for the analysis in 2020 by excluding those lost to follow-up and students who were myopic in the first round. The primary outcomes were the prevalence of myopia and the effect of time outdoors on myopia. The baseline characteristics of the included students were described, and the correlation between time spent outdoors and myopia in the three rounds of data was analyzed by a correlation chi-square test. Then, the generalized estimation equation (GEE) was used to estimate the influence of time spent outdoors on myopia after follow-up.There were 3571 students with normal baseline vision, and 1508 (42.23%) students progressed from having a normal vision to myopia in the third round, of whom 706 (46.82%) were male and 802 (53.18%) were female. The results of the chi-square test showed that the time spent outdoors of all students and girls, specifically, was related to myopia (P < .05). Next, the GEE was used to analyze the influence of time spent outdoors on myopia after follow-up. After two model adjustments (individual and family-related characteristics of students), students with < 7 hours/week time spent outdoors retained a high myopia rate than ≥14 hours/week (OR = 1.250; 95% CI: 1.070-1.460). Among boys, there was no statistical correlation between time spent outdoors and myopia (P > .05). For girls, compared with students who spent ≥14 hours/week outdoors, students with <7 hours/week spent outdoors retained a higher myopia rate (OR = 1.355; 95%CI: 1.067-1.720).Increased time spent outdoors can delay the development of myopia. In terms of gender, girls should be targeted to more effectively prevent and control the development and progression of myopia.

Myopia progression varies with age and severity of myopia

Objective

To investigate annual myopia progression in individuals from South Indian states across different age groups, and its association with age of onset and severity of myopia.

Methods

This retrospective study included the data of 6984 myopes (range: 1–30 years), who visited at least twice to LV Prasad Eye Institute and on whom a standard retinoscopy technique was performed to determine refractive error. Based on spherical equivalent (SE) refractive error, individuals were classified into mild, moderate, high and severe myopic groups. Myopia progression was calculated as difference between SE at 1-year follow-up visit and at baseline. To determine the age-specific myopia progression, individuals were further categorized as myopes who are at least 15 years or younger and those who are above 15.

Results

The mean annual progression of myopia was influenced by both the age group (p < 0.001) and severity type of myopia (p < 0.001). The overall mean myopia progression ranged from -0.07 ± 0.02 D (standard error) to -0.51 ± 0.02 D across different age groups with maximum change in refractive error noted in children aged 6–10 years and the least in adults aged 26–30 years. Myopia progression was greater in severe myopes, followed by high, moderate, mild myopes and in individuals aged ≤ 15 years compared to those aged >15 years (-0.45 ± 0.01 vs. 0.14 ± 0.01, p < 0.001). Severe myopes alone had similar annual myopia progression rate irrespective of age (i.e ≤15 and >15 years, p = 0.71). Early onset of myopia was associated with high myopia in adulthood.

Conclusion

The magnitude of myopia progression in children from South Indian states is comparable to that of Caucasians and Chinese. The greater progression in ‘severe myopes’ across different age groups emphasize the need for regular follow-ups, monitoring axial lengths, and anti-myopia strategies to control myopia progression irrespective of the age and degree of myopia.

Recent Epidemiology Study Data of Myopia

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

Prevalence of myopia among disadvantaged Australian schoolchildren: A 5-year cross-sectional study

Purpose

Myopia prevalence is influenced by environmental factors including heritability and social disadvantage. The current prevalence of myopia among disadvantaged school children in Australia has not been reported. Therefore, this study analyses refractive data for children from rural and outer suburban areas.

Methods

The records of 4,365 children aged 6–15 visiting a city-based government-school respite care center during the years 2014/2016/2018 were analyzed for right eye non-cycloplegic spherical equivalent refraction (SER). The prevalence of myopia (SER≤-0.50D) was compared with historical data.

Results

The prevalence of myopia was 3.5%, 4.4% and 4.3% in 2014, 2016 and 2018, respectively. The prevalence of myopia increased with age (P<0.0001), but was not related to sex or year of testing (all P >0.05). The overall mean SER was 0.89±0.86D, 0.62±0.89D and 0.56±0.95 in 2014, 2016 and 2018, respectively. Mean SER was associated with year of testing, age (all P <0.0001) and sex (P = 0.03). Mean SER decreased slightly from 2014 to 2018 and demonstrated a significant shift towards less hyperopia with increasing age. Mean SER of females was higher than that of males and decreased faster than in males with age (P _interaction = 0.03).

Conclusions

Myopia prevalence increased with age. The mean SER decreased slightly from 2014 to 2018. Sex differences in the rate of change with age was observed. Compared with 40 years ago, the prevalence of myopia has doubled, but it remains significantly lower than in school children of a similar age living in established urban areas that are regarded as having a higher socioeconomic status.

The Prevalence of Myopia and Factors Associated with It Among Secondary School Children in Rural Vietnam

Purpose

To assess the prevalence of myopia and associated factors among secondary school children in a rural area of Vietnam.

Methods

A school-based cross-sectional study of children in grades six to nine was conducted in four secondary schools in Hoang Mai town, Nghe An Province, Vietnam, during December 2018 and January 2019. The status of myopia was defined as a spherical equivalent objective refractive error of −0.50 D or worse in either eye. A case–control study was conducted to explore factors associated with myopia, where children with myopia were considered to be cases, and children without myopia were considered to be controls. Factors associated with myopia were analyzed using univariate and multivariate logistic regression.

Results

The prevalence of myopia among secondary school children was 14.2% (95% CI: 12.7–15.7%) and tended to increase with grade, from 10.5% in grade six to 17.7% in grade nine. Myopia prevalence in girls was significantly higher than in boys. Factors associated with myopia were a mother with a college/university education (OR = 2.5, 95% CI = 1.2–5.3), parents who wore spectacles (OR = 2.0, 95% CI = 1.1–3.8), distance from near work (OR = 5.2, 95% CI = 3.5–7.9), and taking breaks after 30 minutes of continued reading (OR = 1.6, 95% CI = 1.1–2.5). However, there were inverse associations with myopia for children belonging to the wealthiest households (OR = 0.2, 95% CI = 0.1–0.5) and time spent performing outdoor activities (OR = 0.6, 95% CI = 0.4–0.9).

Conclusion

Our study showed that the prevalence of myopia is considerable among secondary children in rural areas of Vietnam. The prevalence of myopia tended to increase among children in higher grade levels. Thus, appropriate interventions should be developed and conducted to deal with the issue of school-age myopia.

Rationale and protocol for the 7- and 8-year longitudinal assessments of eye health in a cohort of young adults in the Raine Study

INTRODUCTION

Eye diseases and visual impairment more commonly affect elderly adults, thus, the majority of ophthalmic cohort studies have focused on older adults. Cohort studies on the ocular health of younger adults, on the other hand, have been few. The Raine Study is a longitudinal study that has been following a cohort since their birth in 1989-1991. As part of the 20-year follow-up of the Raine Study, participants underwent a comprehensive eye examination. As part of the 27- and 28-year follow-ups, eye assessments are being conducted and the data collected will be compared with those of the 20-year follow-up. This will provide an estimate of population incidence and updated prevalence of ocular conditions such as myopia and keratoconus, as well as longitudinal change in ocular parameters in young Australian adults. Additionally, the data will allow exploration of the environmental, health and genetic factors underlying inter-subject differential long-term ocular changes.

METHODS AND ANALYSIS

Participants are being contacted via telephone, email and/or social media and invited to participate in the eye examination. At the 27-year follow-up, participants completed a follow-up eye screening, which assessed visual acuity, autorefraction, ocular biometry and ocular sun exposure. Currently, at the 28-year follow-up, a comprehensive eye examination is being conducted which, in addition to all the eye tests performed at the 27-year follow-up visit, includes tonometry, optical coherence tomography, funduscopy and anterior segment topography, among others. Outcome measures include the incidence of refractive error and pterygium, an updated prevalence of these conditions, and the 8-year change in ocular parameters.

ETHICS AND DISSEMINATION

The Raine Study is registered in the Australian New Zealand Clinical Trials Registry. The Gen2 20-year, 27-year and 28-year follow-ups are approved by the Human Research Ethics Committee of the University of Western Australia. Findings resulting from the study will be published in health or medical journals and presented at conferences.

TRIAL REGISTRATION NUMBER

ACTRN12617001599369; Active, not recruiting.

The impact of computer use on myopia development in childhood: The Generation R study

Environmental factors are important in the development of myopia. There is still limited evidence as to whether computer use is a risk factor. The aim of this study is to investigate the association between computer use and myopia in the context of other near work activities. Within the birth cohort study Generation R, we studied 5074 children born in Rotterdam between 2002 and 2006. Refractive error and axial length was measured at ages 6 and 9. Information on computer use and outdoor exposure was obtained at age 3, 6 and 9 years using a questionnaire, and reading time and reading distance were assessed at age 9 years. Myopia prevalence (spherical equivalent ≤-0.5 dioptre) was 11.5% at 9 years. Mean computer use was associated with myopia at age 9 (OR = 1.005, 95% CI = 1.001-1.009), as was reading time and reading distance (OR = 1.031; 95% CI = 1.007-1.055 (5-10 h/wk); OR = 1.113; 95% CI = 1.073-1.155 (>10 h/wk) and OR = 1.072; 95% CI = 1.048-1.097 respectively). The combined effect of near work (computer use, reading time and reading distance) showed an increased odds ratio for myopia at age 9 (OR = 1.072; 95% CI = 1.047-1.098), while outdoor exposure showed a decreased odds ratio (OR = 0.996; 95% CI = 0.994-0.999) and the interaction term was significant (P = 0.036). From our results, we can conclude that within our sample of children, increased computer use is associated with myopia development. The effect of combined near work was decreased by outdoor exposure. The risks of digital devices on myopia and the protection by outdoor exposure should become widely known. Public campaigns are warranted.

A review on the epidemiology of myopia in school children worldwide

Background

Due to high prevalence myopia has gained importance in epidemiological studies. Children with early onset are at particular risk of complications associated with myopia, as progression over time might result in high myopia and myopic macular degeneration. Both genetic and environmental factors play a role in the increasing prevalence of myopia. The aim of this study is to review the current literature on epidemiology and risk factors for myopia in school children (aged 6–19 years) around the world.

Main body

PubMed and Medline were searched for the following keywords: prevalence, incidence, myopia, refractive error, risk factors, children and visual impairment. English language articles published between Jan 2013 and Mar 2019 were included in the study. Studies were critically reviewed for study methodology and robustness of data. Eighty studies were included in this literature review.

Myopia prevalence remains higher in Asia (60%) compared with Europe (40%) using cycloplegic refraction examinations. Studies reporting on non-cycloplegic measurements show exceptionally high myopia prevalence rates in school children in East Asia (73%), and high rates in North America (42%). Low prevalence under 10% was described in African and South American children. In recent studies, risk factors for myopia in schoolchildren included low outdoor time and near work, dim light exposure, the use of LED lamps for homework, low sleeping hours, reading distance less than 25 cm and living in an urban environment.

Conclusion

Low levels of outdoor activity and near work are well-established risk factors for myopia; this review provides evidence on additional environmental risk factors. New epidemiological studies should be carried out on implementation of public health strategies to tackle and avoid myopia. As the myopia prevalence rates in non-cycloplegic studies are overestimated, we recommend considering only cycloplegic measurements.

Refractive Change and Incidence of Myopia Among A Group of Highly Selected Senior High School Students in China: A Prospective Study in An Aviation Cadet Prerecruitment Class

Purpose

To assess the incidence rate of myopia, refractive change, and the effects of influencing factors on a group of highly selected senior high school students in an Aviation Cadet prerecruitment class in China.

Methods

A total of 800 nonmyopic, male, Grade 9 students aged 14- to 16-years old with cycloplegic refraction of -0.25 or greater diopters (D) to 1.75 D or less in both eyes were enrolled in May 2016. During their senior high school studies, students had one 20-minute physical training period a day, and they were encouraged to participate in outdoor activities during class recess without any time limits. The first follow-up was 8 months after enrollment when they were in Grade 10, and the second follow-up was 1 year after the first follow-up when they were in Grade 11. Comprehensive ocular examinations and a detailed questionnaire, which included questions about outdoor activity time, parental myopia, and near work, were completed at each follow-up.

Results

The average spherical equivalent refraction (SER) of the right eyes was 0.39 ± 0.44 D at baseline, 0.16 ± 0.41 D at the first follow-up, and -0.10 ± 0.38 D at the second follow-up. The cumulative refractive change was -0.50 D (95% confidence interval [CI], -0.53 to -0.47). The cumulative incidence rate of myopia was 15.5% (124/800). Incident myopia was significantly associated with outdoor activity for more than 1 versus less than 0.5 hr/d (odds ratio [OR] = 0.272, 95% CI, 0.132-0.560), baseline refraction (OR = 0.079, 95% CI, 0.041-0.153), maternal myopia (OR = 2.251, 95% CI, 1.160-4.368), longer class time (OR =3.215, 95% CI, 1.088-9.499), frequent, continuous, and long time reading/writing (OR = 1.620, 95% CI, 1.022-2.570), and shorter reading/writing distance (OR = 1.828, 95% CI, 1.065-3.140). In multiple linear regression model, having outdoor activity for more than 1 hr/d was protective from cumulative SER decrease. A higher baseline refraction together with longer reading/writing time, frequent, continuous, and longtime reading/writing, and shorter reading/writing distance were risk factors for SER decrease.

Conclusions

In this cohort of highly selected, nonmyopic students, longer outdoor activity time was a protective factor for both incident myopia and refractive change of myopic shift. The risk factors for incident myopia included lower hyperopic baseline refraction, more near work, and maternal myopia. The risk factors for refractive change of myopic shift included more hyperopic baseline refraction and more near work.

Risk Factors for Incident Myopia among Teenaged Students of the Experimental Class of the Air Force in China

Background

In recent decades, the prevalence rate of myopia has markedly increased, especially among teenagers. Our purpose was to determine the incidence of myopia and identify the related risk factors among schoolchildren in the experimental classes of the Air Force in China.

Methods

In May 2015, this 3-year prospective cohort study enrolled 522 boys (age, 14–16 years) attending grade 10 in 16 high schools in 15 cities in China. Cycloplegic refraction was examined using retinoscopy in both eyes at the baseline and follow-up (3 years). A detailed questionnaire was completed by the students at the 3-year follow-up and included questions on parental myopia and on the total time spent doing near work and outdoor activities each week.

Results

The incidence of myopia at the 3-year follow-up was 27.01% (141/522, 95% confidence interval (CI): 23.38% to 30.98%). The refractive change was −0.46 D (95% CI: −0.49 to −0.42 D). More hyperopic or less myopic baseline refraction, outdoor activity time per week ≥14 h (odds ratio (OR) = 0.464, 95% CI: 0.227 to 0.950), and reading/writing distance ≥ 30 cm (OR = 0.505, 95% CI: 0.270 to 0.944) were significant protective factors against incident myopia. Near-work time ≥28 h per week was a significant risk factor (OR = 2.579, 95% CI: 1.314 to 5.061). Parental myopia, age at the start of primary school, continuous reading/writing for ≥1 h, sleep duration per week <49 h, and one or more dietary biases were not significant risk factors (P > 0.05).

Conclusion

A more hyperopic baseline refraction, more time spent outdoors, and longer writing/reading distance were protected against myopia onset, while more near-work time was a risk factor.

IMI - Myopia Control Reports Overview and Introduction

With the growing prevalence of myopia, already at epidemic levels in some countries, there is an urgent need for new management approaches. However, with the increasing number of research publications on the topic of myopia control, there is also a clear necessity for agreement and guidance on key issues, including on how myopia should be defined and how interventions, validated by well-conducted clinical trials, should be appropriately and ethically applied. The International Myopia Institute (IMI) reports the critical review and synthesis of the research evidence to date, from animal models, genetics, clinical studies, and randomized controlled trials, by more than 85 multidisciplinary experts in the field, as the basis for the recommendations contained therein. As background to the need for myopia control, the risk factors for myopia onset and progression are reviewed. The seven generated reports are summarized: (1) Defining and Classifying Myopia, (2) Experimental Models of Emmetropization and Myopia, (3) Myopia Genetics, (4) Interventions for Myopia Onset and Progression, (5) Clinical Myopia Control Trials and Instrumentation, (6) Industry Guidelines and Ethical Considerations for Myopia Control, and (7) Clinical Myopia Management Guidelines.

Myopia Growth Chart Based on a Population-Based Survey (KNHANES IV-V): A Novel Prediction Model of Myopic Progression in Childhood

PURPOSE

To introduce a novel myopia growth chart based on a population-based survey for the prediction of myopic progression.

METHODS

The study included 7,695 Korean participants aged 5 to 20 years from a population-based health survey (Korean National Health and Nutrition Examination Survey IV-V). The authors collected spherical equivalent (SE) data converted from noncycloplegic refraction data. To create a myopia growth chart, data were arranged in the order of SE from hyperopia to myopia to acquire specific percentiles of the SE by age. Myopia progression rates were calculated between two specific ages in each percentile.

RESULTS

The mean age of the participants was 11.8 years and the mean SE was -1.82 diopters (D). The SE of the 10th percentile was +0.72 D for participants aged 5 and -0.25 D for those aged 20 years, resulting in a total change in refraction of -0.97 D. In contrast, the SE of the 90th percentile was -0.75 D for participants aged 5 years and -6.73 D for those aged 20 years, showing myopia progression of -5.98 D. The myopia progression rate from 5 to 20 years of age was estimated as -0.06, -0.15, and -0.40 D/year in the 10th, 50th, and 90th percentile groups, respectively.

CONCLUSIONS

The myopia growth chart may be used to diagnose the severity or to estimate the progression of myopia. A patient in a higher percentile of myopia for his or her age may have myopia progressing at a faster rate and thus require close observation. [J Pediatr Ophthalmol Strabismus. 2019;56(2):73-77.].