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

Short-term choroidal changes as early indicators for future myopic shift in primary school children: results of a 2-year cohort study

BACKGROUND

To assess predictive value of short-term choroidal changes for future myopic shift in children.

METHODS

577 eyes of 289 primary school children were prospectively followed for 2 years. Cycloplegic refractions at baseline, 1 year and 2 years, and choroidal measurements by optical coherence tomography at baseline and 3 months, were used for analyses. Myopic shift was defined as refraction change of at least -0.50 dioptre/year, at 2 years compared with baseline.

RESULTS

228 participants (455 eyes) completed 2-year follow-up. Approximately 37.6% of 311 initially non-myopic eyes and 73.6% of 144 initially myopic eyes developed a myopic shift. Notably, at 3 months greater reductions were found in initially myopic eyes with myopic shift, than in those without myopic shift-in choroidal thickness (ChT), luminal area (LA), stromal area (SA) and total choroidal area (TCA), but no significant differences in any choroidal parameters were observed between non-myopic eyes, with and without myopic shift. Multivariable analyses showed that in myopic eyes, each percentage increase in ChT, LA, SA and TCA was associated with reduced odds of myopic shift (all p<0.001). Similar associations were observed in non-myopic eyes, with smaller effects than in myopic eyes. Adding a 3-month percentage change of each choroidal parameter to a basic model including age, gender, parental myopia and baseline refraction significantly improved the predictive performance in myopic eyes (area under the receiver operating characteristic curves increasing from 0.650 to approximately 0.800, all p<0.05), but not in non-myopic eyes.

CONCLUSION

Short-term choroidal changes could act as early indicators for future myopic shift in children.

Slowing of Greater Axial Length Elongation Stemming from the Coronavirus Disease 2019 Pandemic with Increasing Time Outdoors: The Tokyo Myopia Study

Purpose

To investigate the changes in axial length (AL) elongation and other ocular parameters before and during the coronavirus disease 2019 pandemic.

Design

A longitudinal school-based study.

Participants

Public elementary schoolchildren in Tokyo (grades 1-6; age, 6-12 years) participated in this study from 2018 to 2021.

Methods

All participants underwent eye examinations and provided written consent to measurements of the noncycloplegic refraction and ocular biometry including AL, among others. The students' parents also completed a questionnaire about the students' lifestyles. We included the right eye in our analysis and compared the changes in the ocular parameters among the periods using a linear mixed-effects model for repeated measures and examined the univariate and step-wise multiple regression analyses to evaluate the associations between myopia and other covariates.

Main Outcome Measures

Changes in AL elongation and other ocular parameters from 2018 to 2019 (prepandemic), that of 2019 to 2020 (immediately after the pandemic onset), and that of 2020 to 2021 (during the pandemic).

Results

A total of 578 students before the pandemic period, 432 immediately after the pandemic onset, and 457 during the pandemic period were evaluated. The changes in the ALs and spherical equivalents (SEs) a year before, immediately after onset, and during the pandemic were 0.31 mm/-0.20 diopter, 0.38 mm/-0.27 diopter, and 0.28 mm/-0.47 diopter, respectively (ALs, P < 0.001; SEs, P = 0.014). The results of the questionnaire showed that time spent outdoors daily had changed during the 3 years to 79, 63, and 77 minutes/day, respectively (P < 0.001). Time spent using smartphones or tablets increased year by year to 41, 52, and 62 minutes/day (P < 0.001). The greatest AL elongation occurred during the period when the shortest amount of time was spent outdoors during the 3 years.

Conclusions

These results suggested that the school closures and decreasing time spent outdoors might have caused greater AL elongation among schoolchildren in Tokyo; however, it is possible that, although the time spent in near work still increased, the return to the time spent outdoors to the prepandemic levels may have affected the slowing of AL elongation after lockdown.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Proteomic analysis reveals key differences in pro-stromal corneal tissue between highly myopic males and females

Background and purpose

Nowadays, myopia has become a highly prevalent disease globally, especially in East Asia. Epidemiological studies have found that there may be sex differences in the occurrence and progression of myopia, with females having a higher incidence of myopia and higher risk of myopia progression. The purpose of this study was to explore the sex differences in myopic cornea using corneal stroma removed by small incision lenticule extraction (SMILE) surgery.

Methods

The corneal stroma of females with high myopia (FH) and males with high myopia (MH) were subjected to proteomic assays. Proteomic-related data were statistically analyzed using software such as MaxQuan, KAAS, Proteome Discovery, etc. The total number of proteins in the cornea and the proteins specifically expressed in the two groups were counted, and the differentially expressed proteins in the two groups were identified by expression fold change >2 and p-value <0.05, and volcano plots were constructed, and functional enrichment analysis, subcellular organelle analysis, and molecular interaction were implemented.

Results

Ten samples from each group were analyzed. Twenty-seven proteins were down-regulated and 27 proteins were up-regulated in the FH group, of which 23 proteins were up-regulated in the range of 2-10-fold and 4 proteins were up-regulated in the range of >10-fold. Comparative proteomic analysis of the cornea of male and female patients with high myopia revealed that the expression of corneal extracellular matrix and collagen I, III, V, and VIII-associated proteins were increased in the cornea of female patients, and the transforming growth factor-β (TGF-β)/Smad pathway was an important pathway obtained by functional analysis.

Conclusion

Comparative proteomic analysis of cornea from male and female patients with high myopia revealed increased expression of proteins related to extracellular matrix and collagen I, III, V, and VIII in female patients, and the TGF-β/Smad pathway was an important pathway obtained from the functional analysis, suggesting that extracellular matrix remodeling and collagen fiber synthesis may be more active in the cornea of female patients.

Establishing and Validating Refractive Error Reference Values for Myopia Prediction Among Children Aged 6-12 Years - Jiangsu Province, China, 2018-2023

What is already known about this topic?

Previously, it has been proved that a simplified model that uses refraction error value provides a robust and efficient means of predicting myopia for non-myopic students. Intervention targeting non-myopic children with alert refraction errors (or insufficient hyperopia reserve) holds significant importance in reducing the incidence rate of myopia.

What is added by this report?

This study, comprising two phases (surveillance and cohort studies), was aiming to pinpoint the precise refractive error value for the onset of myopia prediction among non-myopic children in Jiangsu Province.

What are the implications for public health practice?

First, when conducting myopia screenings using pupil dilation for non-myopic populations: the cycloplegic 50th percentile refractive error emerges as a more precise predictive indicator. Second, when conducting myopia screenings without pupil dilation: this study advocates for the incorporation of axial length (AL) and corneal curvature (CC) values as supplementary indicators in screenings.

Characteristics of Peripheral Retinal Refraction and Its Role in Children with Different Refractive States

Introduction

Peripheral retinal refraction plays a crucial role in myopia, but the specific mechanism is not clear. We refined the retinal partitions to explore the characteristics of peripheral retinal refraction and its role in emmetropic, low, and moderate myopic children aged 6 to 12 years.

Methods

A total of 814 subjects (814 eyes) were enrolled in the study. The participants were divided into three groups according to the central spherical equivalent refraction (SER), which were emmetropia group (E), low myopia group (LM) and moderate myopia group (MM). Multispectral refractive topography (MRT) was used to measure the retinal absolute and relative refractive difference value (RDV) in different regions. The range was divided into superior, inferior, temporal, and nasal RDV (SRDV, IRDV, TRDV, and NRDV) on the basis of several concentric circles extending outward from the macular fovea (RDV15, RDV30, RDV45, RDV30-15, RDV45-30, and RDV-45). Kruskal-Wallis test was used to analyze the differences of peripheral refraction for all the regions among the three groups. Spearman rank correlation was performed to explore correlations between SER and RDV, axial length (AL) and RDV.

Results

The absolute value of RDV decreased with increasing degree of myopia in all regions (P < 0.01). Subjects with different refractive degrees had different relative value of RDV. In nasal position within 45° and temporal position within 30°, the peripheral retina exhibited significantly different relative hyperopic refractive status among Group E, Group LM, and Group MM (P < 0.05). SER was negatively correlated with NRDV within 30° (especially in the range of NRDV30-15) (r = -0.141, P < 0.01), positively correlated with TRDV within 15° (r = 0.080, P = 0.023), and not significantly correlated with SRDV and IRDV when the retina was divided into four parts. AL was positively correlated with NRDV within 30° (especially in the range of NRDV30-15) (r = 0.109, P = 0.002), negatively correlated with TRDV within 15° (r = -0.095, P = 0.007).

Conclusions

The peripheral defocus has significant implications for the genesis of myopia. The peripheral defocus of the horizontal direction, especially within the range of NRDV30, has greater effect on the development of myopia in children. Higher NRDV30 is associated with lower SER and longer AL.

Association of choroidal thickness and blood flow features with asymmetric axial lengths in children with unilateral myopic anisometropia

BACKGROUND

Considering that changes in the choroidal thickness are closely related to ocular growth, we studied the choroidal thickness (CT) and the blood flow features in children with unilateral myopic anisometropia (UMA) as well as investigating the relationship between choroidal changes and myopia.

METHODS

Subjective refractive, axial length (AL), and biometric parameters were measured in 98 UMA children (age: 8-15 years). CT and choroidal blood-flow features, including the choroidal vessel volume (CVV), choroidal vascularity index (CVI), and choriocapillaris perfusion area (CCPA), were measured through swept-source optical coherence tomography angiography. The macular region was categorized into four concentric circles of diameters 0-1 mm (central fovea), 1-3 mm (parafovea), 3-6 mm (perifovea), and 6-9 mm (extended), and further categorized into superior (S), inferior (I), temporal (T), and nasal (N) quadrants.

RESULTS

The aforementioned four regions of myopic eyes displayed significantly lower CT, CVV, and CVI than those of non-myopic eyes. CCPA changes differed across different regions of both the eyes (parts of N and T quadrants). There was an inverse association between CT and the interocular AL difference (central and other regions S, T quadrant). No correlation was noted between CVV and CVI with interocular AL difference. CT and CVV were positively correlated in the 0-6-mm macular region of myopic eyes (Spearman correlation coefficient = 0.763, P < 0.001).

CONCLUSIONS

In UMA children, CCT and blood flow may be related to myopia progression. A robust correlation between CT and CVV in the 0-6-mm macular region and reduced CT and diminished blood flow indicated an association with myopia.

Survey on pattern of myopia in school children in Hangzhou after the COVID-19 pandemic: a school-based vision screening study

BACKGROUND

Myopia is a major health issue around the world. Myopia in children has increased significantly during the COVID-19 pandemic in China, but reports are scarce on the prevalence of myopia following the pandemic. This study collected vision screening data of school children in China for five consecutive years to observe the changes in myopia after the pandemic and compare the observed prevalence of myopia before and after the pandemic.

METHODS

A school-based vision screening study used stratified samplings to collect the vision screening data in school children aged 6-13 from 45 primary schools in Hangzhou. Vision screening data including uncorrected visual acuity(UCVA) and spherical equivalent refraction(SER). Calculating the mean of SER and the prevalence of myopia and hyperopia from 2019 to 2023.

RESULTS

A total of 79,068 screening results (158,136 eyes) were included in the analysis. A substantial myopic shift (approximately -0.30 diopters [D] on average) was found in 2020 and 2021 compared with 2019 in all age groups and a substantial myopic shift (approximately 0.4 D on average) was found in 2022 compared with 2021. A slight myopic shift (approximately -0.14 D on average) was found in 2023 compared with 2022. The prevalence of myopia in all age groups was the highest for five years in 2020 or 2021, which was 31.3% for 6-year-olds, 43.0% for 7-year-olds, and 53.7% for 8-year-olds. A positive change in the prevalence rate of myopia was found at 6 years old (0.59%, 0.12%, 0.36%, 0.25%, p < 0.001). The change in prevalence rate in myopia was shifted slightly in children aged 10-13 years. Children aged 8 to 13 years had a slight increase in myopia prevalence from 2022 to 2023. The prevalence of hyperopia was low and stable in all grade groups, ranging from 0.7% to 2.2% over five years.

CONCLUSION

Myopia in children has increased rapidly during the COVID-19 pandemic. After the pandemic, the prevalence of myopia in children gradually decreased temporarily and then rebounded. Myopic shift was more apparent in younger children. Myopic shift in children may be related to the reduction of outdoor time, less light, and near work habits, and further research is needed.

Trends in myopia development among Chinese children and adolescents in Xuzhou during one academic year

Purpose

This study investigates the prevalence and progression of myopia among primary and secondary school students in Xuzhou City, China, during one academic year.

Methods

The study employed a prospective research design and utilized a whole-group sampling method to conduct non-cycloplegic spot photo screenings on 37,938 students from 44 primary and secondary schools in Xuzhou City, China. A one-year study was conducted to gather spherical equivalent refraction (SER), and subsequent analysis was carried out to explore the disparities in myopia prevalence among primary and secondary school students within the same academic year, as well as the progression of myopia.

Results

During the 2022 academic year, the overall prevalence of myopia in the first and second semesters was 62.6 and 64.2% respectively, indicating an increasing trend. Particularly in primary school (Grades 1-6), the prevalence of myopia increased with higher grade levels, and significant variations in myopia prevalence were observed mainly in grades 1-3 and 7 (p < 0.05). The incidence rate of myopia in middle school remained stable, while in primary school, there was a positive correlation between myopia incidence and the grade level, with the highest rate of 20.1% in grade 6. Among the myopic population, the median value of spherical equivalent refraction slightly decreased between the two semesters. The proportion of high myopia increased among students in grades 5-8.

Conclusion

Our study revealed that within one academic year, the prevalence of myopia and the severity of myopia have significantly increased in Xuzhou City, China, accompanied by an increase in the proportion of high myopia. For different grade levels, we should adopt personalized prevention and control measures, with a particular focus on lower grade levels and students who have just entered a new grade.

Normative value of hyperopia reserve and myopic shift in Chinese children and adolescents aged 3-16 years

BACKGROUND

This research aims to generate normative values of hyperopia reserve and refractive progression as effective tools to estimate the risk of myopia.

METHODS

A 1-year follow-up study was conducted among Chinese children and adolescents aged 3-16 years selected from schools and kinder gardens using cluster sampling. All participants underwent examinations including visual acuity, axial length and cycloplegic autorefraction (1% cyclopentolate). Percentiles of spherical equivalent (SE) were calculated using Lambda-Mu-Sigma (LMS) method. Age-specific refractive progression and hyperopia reserve were determined by backward calculation.

RESULTS

Of 3118 participants, 1702 (54.6%) were boys with a mean baseline age of 7.30 years. The 50th percentile of SE estimated by LMS decreased from 1.04 D at 3 years to -2.04 D at 16 years in boys, while from 1.29 D to -2.81 D in girls. The 1-year refractive progression of myopes (0.81 D) was greater than that of non-myopes (0.51 D). The normative value of hyperopia reserve was 2.64 (range: 2.40 D-2.88 D) at 3 years and -0.35 (range: -0.50 to -0.17) D at 16 years, with the maximum progression of 0.35 D at the age of 6 years.

CONCLUSION

Age-specific normative values of hyperopia reserve and yearly myopic shift in children and adolescents aged 3-16 years were provided, helping identify and monitor myopia and giving prevention in advance.

Daily Low-Level Red Light for Spherical Equivalent Error and Axial Length in Children With Myopia: A Randomized Clinical Trial

Importance

Treatments are needed to slow progression of or reduce incidence of myopia.

Objective

To evaluate the efficacy and safety of daily 650-nm low-level red light (LLRL) for myopia treatment.

Design, Setting, and Participants

Single-masked, randomized clinical trial at 1 site in China. Baseline measurements were completed from August to September 2021. Participants were children aged 6 to 12 years with spherical equivalent error (SER) of -6 diopters (D) to 3 D. Data were analyzed from March to July 2023.

Interventions

Irradiation daily with 650-nm LLRL for 3 minutes twice daily 4 or more hours apart or no intervention.

Main Outcomes and Measures

Primary outcomes were changes in cycloplegia SER and axial length (AL) at 6- and 12-month follow-up visits. Safety was assessed on masked fundus photograph evaluations.

Results

A total of 336 children were randomly allocated into the LLRL group or control group in a 1:1 ratio. The control group contained 86 female patients (51.2%), and the treatment group contained 90 female patients (53.6%). The mean (SD) age, SER, and AL were 9.0 (1.9) years, -1.3 (1.5) D, and 23.8 (1.0) mm for all patients. A total of 161 (95.8%) in the LLRL group and 159 (94.6%) in the control group returned for the 6-month follow-up. A total of 157 (93.5%) in the LLRL group and 152 (90.5%) in the control group returned for the 12-month follow-up. Mean (SD) changes in SER were 0.15 (0.16) D and -0.26 (0.21) D for the LLRL group and the control group, respectively (difference, -0.41 D; 95% CI, -0.48 to -0.34 D; P < .001), at 6 months and 0.24 (0.27) D and -0.65 (0.33) D for the LLRL group and the control group, respectively (difference, -0.89 D; 95% CI, -0.95 to -0.83 D; P < .001), at 12 months. Mean (SD) changes in AL were -0.06 (0.08) mm and 0.13 (0.12) mm for the LLRL group and control group, respectively (difference, 0.19 mm; 95% CI, 0.16 to 0.22 mm; P < .001), at 6 months and -0.11 (0.10) mm and 0.26 (0.16) mm for the LLRL group and control group, respectively (difference, 0.37 mm; 95% CI, 0.34 to 0.40 mm; P < .001). Masked fundus photograph review did not identify retinal changes in either group.

Conclusions and relevance

These findings suggest daily use of 650-nm LLRL for 1 year can slow progression of SER and AL without safety concerns identified. Confirmation of these findings at independent sites seems warranted, as well as determining whether these effects can be sustained with or without continued treatment and whether LLRL has any effect on pathological myopia.

Trial Registration

ChiCTR2200058963.

miR-92b-3p protects retinal tissues against DNA damage and apoptosis by targeting BTG2 in experimental myopia

BACKGROUND

Myopia is one of the eye diseases that can damage the vision of young people. This study aimed to explore the protective role of miR-92b-3p against DNA damage and apoptosis in retinal tissues of negative lens-induced myopic (LIM) guinea pigs by targeting BTG2.

METHODS

Biometric measurements of ocular parameters, flash electroretinogram (FERG), and retinal thickness (RT) were performed after miR-92b-3p intravitreal injection in LIM guinea pigs. The apoptotic rate was detected by Annexin V-FITC/PI double staining, and the change in mitochondrial membrane potential was measured by JC-1 staining. Retinal apoptosis and expression of p53, BTG2, and CDK2 were explored by TdT-mediated dUTP-biotin nick labeling (TUNEL) and immunofluorescence staining assays, respectively. BTG2 and its upstream and downstream molecules at gene and protein levels in retinal tissues were measured by real-time quantitative PCR (qPCR) and Western blotting.

RESULTS

Compared with normal controls (NC), the ocular axial length of LIM guinea pig significantly increased, whereas refraction decreased. Meanwhile, dMax-a and -b wave amplitudes of ERG declined, retinal thickness was decreased, the number of apoptotic cells and apoptotic rate in LIM eyes was exaggerated, and the mitochondrial membrane potential significantly decreased. In addition, results of qPCR and Western blot assays showed that the expression levels of p53, BTG2, CDK2, and BAX in LIM guinea pigs were higher than the levels of the NC group, whereas the BCL-2 expression level was decreased. By contrast, the miR-92b-3p intravitreal injection in LIM guinea pigs could significantly inhibit axial elongation, alleviate DNA damage and apoptosis, and thus protect guinea pigs against myopia.

CONCLUSION

In conclusion, p53 and BTG2 were activated in the retinal tissue of myopic guinea pigs, and the activated BTG2 could elevate the expression of CDK2 and BAX, and attenuate the expression of BCL-2, which in turn promote apoptosis and eventually lead to retinal thinning and impaired visual function in myopic guinea pigs. The miR-92b-3p intravitreal injection can attenuate the elongation of ocular length and retinal thickness, and inhibit the CDK2, BAX, and p53 expression by targeting BTG2, thereby ameliorating DNA damage and apoptosis in LIM guinea pigs and protecting ocular tissues.

Impact of ophthalmic clinical service use in mitigating myopia onset and progression in preschool children: a retrospective cohort study

BACKGROUND

Although school screenings identify children with vision problems and issue referrals for medical treatment at an ophthalmic hospital, the effectiveness of this approach remains unverified.

OBJECTIVE

To investigate the impact of ophthalmic clinical services on the onset and progression of myopia in preschool children identified with vision impairment.

METHODS

Using data from the Shanghai Child and Adolescent Large-scale Eye Study (SCALE), this retrospective cohort study evaluated the visual development of children from three districts-Jing'an, Minhang, and Pudong-which are representative of geographic diversity and economic disparity in Shanghai's 17 districts. Initially, in 2015, the study encompassed 14,572 children aged 4-6 years, of whom 5,917 needed a referral. Our cohort consisted of 5,511 children who had two or more vision screenings and complete personal information over the follow-up period from January 2015 to December 2020. We divided these children into two groups based on their initial spherical equivalent (SE): a High-risk group (SE > -0.5 D) and a Myopia group (SE ≤ -0.5 D). Within each of these groups, we further categorized children into Never, Tardily, and Timely groups based on their referral compliance to compare the differences in the occurrence and progression of myopia. Cox proportional models were applied to estimate hazard ratios (HRs) for myopia incidence per person-years of follow-up in High-risk group. Generalized additive models(GAM) was used to calculating the progression for annual spherical equivalent changes in all children.

RESULTS

Of the 5,511 preschool children (mean age, 5.25 years; 52.24% male) who received a referral recommendation, 1,327 (24.08%) sought clinical services at an ophthalmic hospital. After six years of follow-up, 65.53% of children developed myopia. The six-year cumulative incidence of myopia in the Never, Tardily, and Timely groups was 64.76%, 69.31%, and 57.14%, respectively. These percentages corresponded to hazard ratios (HRs) of 1.31 (95% CI, 1.10-1.55) for the Tardily group and 0.55 (95% CI, 0.33-0.93) for the Timely group, compared with the Never group. The HRs were adjusted for age, sex, and SE at study entry. Interestingly, the Timely group showed significantly less SE progression than the other groups (P < 0.001), and SE progression was higher in the High-risk group (-0.33 ± 0.37D/year) than in children with myopia (-0.08 ± 0.55D/year).

CONCLUSION

Timely utilization of ophthalmic clinical services among children aged 4 to 6 years who fail school vision screenings can significantly reduce the incidence of myopia and slow SE progression.

The Impact of Sunshine Duration on Myopia in Central China: Insights from Populational and Spatial Analysis in Hubei

Purpose

This study aimed to analyze myopia distribution in Hubei and the impact of regional Sunshine Duration on myopia in children and adolescents.

Patients and Methods

The Cross-sectional study included students (kindergarten to grade 12) through multistage cluster stratified sampling in 17 cities (103 areas) of Hubei, China, who underwent ophthalmic examinations from September 2021 to November 2021. The association of sunshine duration with the prevalence and distribution of myopia was analyzed. Using Moran's index to quantify the distribution relationship, a spatial analysis was constructed.

Results

A total of 435,996 students (53.33% male; mean age, 12.16±3.74 years) were included in the study. A negative association was identified between myopia prevalence and sunshine duration in the region, especially in population of primary students (r=-0.316, p<0.001). Each 1-unit increment in the sunshine duration was associated with a decreased risk of myopia prevalence (OR=0.996; 95% CI, 0.995-0.998; P <0.001). Regression showed a linear relationship between sunshine duration and myopia rates of primary school students [Prevalence%= (-0.1331*sunshine duration+47.73)%, p = 0.02]. Sunshine duration influenced the distribution of myopia rates among primary (Moran's I=-0.206, p<0.001) and junior high school (Moran's I=-0.183, p=0.002). Local spatial analysis showed that areas with low sunshine duration had high myopia prevalence concentration.

Conclusion

This study revealed sunshine duration associations with myopia prevalence at the regional and population levels. The results may emphasize the significance of promptly implementing myopia control in regions with poor sunshine. The effect of sunshine on myopia is pronounced in the early years of education, especially in primary students.

Refraction and ocular biometric parameters in 3-to 6-year-old preschool children : a large-scale population-based study in Chengdu, China

PURPOSE

To understand the ocular biometric parameters characteristics and refractive errors in 3-to 6-year-old preschool children in Chengdu, China, and to investigate the prevalence of refractive errors.

METHOD

A school-based cross-sectional study was conducted in Chengdu from 2020 to2022 with a total of 666 kindergartens. All children were measured by non-cycloplegic autorefraction and uncorrected visual acuity (UCVA) and ocular biometric parameters. Finally, univariate linear regression models were used to analyze the relationship between ocular biometric parameters and refraction.

RESULTS

A total of 108,578 preschool children aged 3-6 underwent examinations, revealing a myopia prevalence of 6.1%. The mean axial length (AL), keratometry (K), corneal radius (CR), axial length/corneal radius (AL/CR) Ratio, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were 22.35 ± 0.69 mm, 43.35 ± 1.58 D, 7.80 ± 0.28 mm, 2.87 ± 0.08, 533.31 ± 32.51 μm, 2.70 ± 0.28 mm, 3.91 ± 0.27 mm, and 15.20 ± 0.68 mm, respectively. With increasing age, AL, CR, AL/CR ratio, CCT, ACD, LT, and VCD also increased. Regardless of age, males consistently exhibited longer AL, flatter corneal curvature, shallower ACD, thicker CCT, thinner LT, and longer VCD compared to females. AL, K, CR, LT, and VCD all showed significant linear relationships with SE (all P < 0.001) in univariate linear regression analysis after adjusting for gender and age.

CONCLUSION

The prevalence of myopia among preschool children aged 3-6 in Chengdu is relatively low. Ocular biometric parameters affecting refractive errors include AL, K, CR, LT, and VCD. The preschool period serves as a critical phase for myopia prevention and control.

Distribution and correlation of refractive parameters in children with different corneal curvatures in southeast China

AIM

To analyze the distribution of refractive status in school-age children with different corneal curvatures (CC) and the correlation between CC and refractive status.

METHODS

A total of 2214 school-aged children of grade 4 in Hangzhou who were screened for school myopia were included. Uncorrected distance visual acuity (UCDVA), non-cycloplegic refraction, axial length (AL), horizontal and vertical corneal curvature (K1, K2) were measured and spherical equivalent (SE), corneal curvature radius (CCR) and axial length/corneal radius of curvature ratio (AL/CR) were calculated. UCDVA<5.0 and SE≤-0.50 D were classified as school-screening myopia. According to the different CCRs, the patients were divided into the lower corneal curvature (LCC) group (CCR≥7.92) and the higher corneal curvature (HCC) group (CCR<7.92). Each group was further divided into the normal AL subgroup and the long AL subgroup. The refractive parameters were compared to identify any differences between the two groups.

RESULTS

Both SE and AL were greater in the LCC group (P=0.013, P<0.001). The prevalence of myopia was 38% in the LCC group and 44% in the HCC group (P<0.001). The proportion of children without screening myopia was higher in the LCC group (62%) than in the HCC group (56%). Among these children without screening myopia, the proportion of long AL in the LCC group (24%) was significantly higher than that in the HCC group (0.012%; P<0.001). The change of SE in the LCC group was less affected by the increase of AL than that in the HCC group.

CONCLUSION

School-aged children in the LCC group have a lower incidence of screening myopia and longer AL. Low CC can mask SE reduction and AL growth to some extent, and the change of AL growth change more in children with low CC than high CC. Before the onset of myopia, its growth rate is even faster than that after the onset of myopia.

Differences in choroidal responses to near work between myopic children and young adults

BACKGROUND

Near work is generally considered as a risk factor for myopia onset and progression. This study aimed to investigate the choroidal responses to a brief-period of near work in children and young adults.

METHODS

Thirty myopic medical students (aged 18-28 years) and 30 myopic children (aged 8-12 years) participated in this study. The submacular total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI) and choriocapillaris flow deficit (CcFD), as well as subfoveal choroidal thickness (SFCT) were measured with swept-source optical coherence tomography/optical coherence tomography angiography (SS-OCT/OCTA) before and immediately after 20 min, 40 min, 60 min of near work at a distance of 33 cm.

RESULTS

In adults, 20 min of near work induced a significant reduction in SFCT (- 5.1 ± 6.5 μm), LA [(- 19.2 ± 18.6) × 103 μm2], SA [(- 8.2 ± 12.6) × 103 μm2] and TCA [(- 27.4 ± 24.9) × 103 μm2] (all P < 0.01). After 40 min of near work, LA was still reduced [(- 9.4 ± 18.3) × 103 μm2], accompanied with a decreased CVI (- 0.39% ± 0.70%) and an increased CcFD (0.30% ± 0.78%) (all P < 0.05). After 60 min of near work, CVI was still reduced (- 0.28% ± 0.59%), and CcFD was still increased (0.37% ± 0.75%) (all P < 0.05). In children, 20 min of near work induced a significant increase in CcFD (0.55% ± 0.64%), while 60 min of near work induced increases in SA [(7.2 ± 13.0) × 103 μm2] and TCA [(9.7 ± 25.3) × 103 μm2] and a reduction in CVI (- 0.28% ± 0.72%) (all P < 0.05). Children exhibited lower near work-induced LA and TCA reduction than adults, with a mean difference of - 0.86% and - 0.82%, respectively (all P < 0.05).

CONCLUSIONS

The temporal characteristics and magnitude of changes of choroidal vascularity and choriocapillaris perfusion during near work was not identical between children and adults. The initial response to near work was observed in choriocapillaris in children, whereas it was observed in the medium- and large-sized vessels in adults.

TRIAL REGISTRATION

Clinical Trial Registry (ChiCTR), ChiCTR2000040205. Registered on 25 November 2020, https://www.chictr.org.cn/bin/project/edit?pid=64501 .

Peripheral and posterior pole retinal changes in highly myopic Chinese children and adolescents : Retinal changes in Chinese children and adolescents

PURPOSE

This study was conducted to evaluate the prevalence and related factors of peripheral and posterior pole retinal changes in highly myopic Chinese children and adolescents.

METHODS

A hospital-based cross-sectional study was designed. A total of 120 subjects with high myopia were recruited and underwent cycloplegic refraction, dilated fundus examination, and optical coherence tomography. A statistical analysis was performed to evaluate the factors associated with peripheral and posterior pole retinal changes.

RESULTS

The mean spherical equivalent refraction of the subjects was - 8.74 ± 2.86 D, and the mean age was 11.45 ± 3.02 years. Snowflake retinal degeneration (27.5%), white without pressure (27.5%), snail-track degeneration (15%), and lattice degeneration (15%) were the most common peripheral retinal changes, while tessellated fundus (84.17%), optic nerve crescents (78.3%), and posterior staphyloma (11.7%) were the most common posterior changes. Subjects with peripheral changes were significantly older, with thinner choroids (OR = 1.194, 95% CI: 1.045-1.363, p = 0.009; OR = 0.993, 95% CI: 0.987-0.999, p = 0.022, respectively). Optic nerve crescents, tessellated fundus, and posterior scleral staphyloma were all associated with thin choroids (OR = 0.990, 95% CI: 0.983-0.997, p = 0.008; OR = 0.983, 95% CI: 0.974-0.991, p < 0.001; OR = 0.974, 95% CI: 0.960-0.987, p < 0.001, respectively).

CONCLUSION

A substantial proportion of the subjects had peripheral and posterior retinal changes. An increased risk of retinal changes was associated with high degrees of myopia, long axial lengths, thin choroids, and older ages among 7-16-year-old individuals.

Effects on radius of curvature and refractive power of the cornea and crystalline lens by atropine 0.01% eye drops

PURPOSE

The morphological changes in the cornea and crystalline lens have not been closely evaluated after the administration of atropine 0.01%. This study aims to evaluate the radii of curvature and refractive power of the cornea and lens in myopic eyes during atropine 0.01% treatment.

METHODS

Children aged 6-14 years with myopia <-6.0 D were randomized to receive atropine 0.01% once nightly with single vision lenses or simply wear single vision lenses. Ocular biometric parameters were measured using the IOLMaster 700 biometry and the radii of corneal and lenticular curvature were simulated using a customized program.

RESULTS

At the 9-month visit, 69 atropine-treated eyes and 50 control eyes were included in the final analyses. In atropine-treated eyes, the posterior corneal surface steepened (-0.05 ± 0.13 mm) and the anterior lenticular surface flattened (0.20 ± 0.69 mm) significantly within 3-6 months, whereas the posterior corneal surface and anterior lenticular surface gradually flattened (0.07 ± 0.23 and 0.32 ± 0.80 mm respectively) in the control eyes over 9 months. The difference in the change of corneal refractive power was significant between groups (-0.03 ± 0.18 D vs. 0.11 ± 0.24 D, p = 0.001), while that in the change of lenticular refractive power was statistically insignificant (0.01 ± 0.92 D vs. -0.22 ± 0.86 D, p = 0.161).

CONCLUSIONS

The administration of atropine 0.01% exhibited a clinically short and subtle impact on the cornea and lens, which may shed light on new targets of action for atropine in inhibiting myopia.

Development of a risk score for myopia: A cohort study conducted among school-aged children in China

PURPOSE

To evaluate the myopia risk in school-aged children one year after lifting a pandemic-related lockdown and develop a tool to identify high-risk groups.

METHODS

In total, 38,079 children without myopia from 38 schools were included. The outcomes were myopia incidence and progression in 1 year after the COVID-19 lockdown was lifted, both obtained by the spherical equivalent refraction (SER). We separated the population into an exploratory (75%) and a validation sample (25%) to construct the risk score model.

RESULTS

In total, 9811 (29.57%) students became myopic, and the overall myopia progression was 0.22 ± 0.62 D. Even less myopia progression was noted in the pre-myopia group at baseline (All: P = 0.045, Boy: P = 0.005). The risk score model included seven predictors: gender, grade, SER at baseline, residence, parental myopia, eye discomfort symptoms, and online courses. The model had a score range of 0-46 and an optimal cutoff of 34. The area under the receiver operating curve of the model was 0.726 (0.719-0.732) for the exploratory sample and 0.731 (0.720-0.742) for the validation sample.

CONCLUSIONS

The risk score can serve as a practical tool for classifying the risk of myopia in school-aged children.

Axial length to corneal radius of curvature ratio and refractive error in Chinese preschoolers aged 4-6 years: a retrospective cross-sectional study

OBJECTIVE

This study aims to investigate the associations of axial length to corneal radius of curvature (AL/CRC) ratio with refractive error and to determine the effect of AL/CRC ratio on hyperopia reserve and myopia assessment among Chinese preschoolers.

METHODS

This was a retrospective cross-sectional study that evaluated subjects aged 4-6 years. AL and CRC were obtained using a non-contact ocular biometer. Correlation analysis was performed to explore the associations of AL/CRC ratio with spherical equivalent refractive error (SER). The accuracy of AL/CRC ratio for hyperopia reserve and myopia assessment was analysed using cycloplegic refraction by drawing receiver operating characteristic (ROC) curves.

RESULTS

The analysis included 1024 participants (537 boys, 52.4%). The mean AL/CRC ratios in hyperopes, emmetropes and myopes were 2.90±0.06, 2.95±0.05 and 3.08±0.07, respectively. The SER was found to be more strongly correlated with AL/CRC ratio (ρ=-0.66, p<0.001) than either AL or CRC alone (ρ=-0.52, p<0.001; ρ=-0.03, p=0.33, respectively). AL/CRC was correlated with SER in hyperopes (ρ=-0.54, p<0.001), emmetropes (ρ=-0.33, p<0.001) and myopes (r=-0.67, p<0.001). For low hyperopia reserve assessment, the area under the ROC curves of AL/CRC ratio was 0.861 (95% CI 0.829 to 0.892), the optimal cut-off value of the AL/CRC ratio was ≥2.955. For myopia assessment, the area under the ROC curves of AL/CRC ratio was 0.954 (95% CI 0.925 to 0.982), the optimal cut-off value of the AL/CRC ratio was ≥2.975.

CONCLUSIONS

The SER showed a better correlation with AL/CRC ratio than either AL or CRC alone, especially in myopes, among children aged 4-6 years. These findings indicate that when cycloplegic refraction is unavailable, AL/CRC ratio could be used as an alternative indicator for identifying low hyperopia reserve and myopia among preschoolers, helping clinicians and parents screen children with low hyperopia reserve before primary school in a timely manner.

Trajectories of spherical equivalent refraction from grades 1 to 4 in Chinese children

BACKGROUND

The development trajectories of children's SER remain unknown. This study aimed to characterize spherical equivalent refraction (SER) trajectories during grades 1-4 in Chinese children.

METHODS

This prospective cohort study included 1226 first-grade non-myopic children from 12 public primary schools, randomly selected in two districts in Guangzhou, China. From November 2018 to March 2022, four-wave ocular examinations and questionnaire surveys have been completed. The group-based trajectory modeling was used to explore SER trajectories in grades 1-4.

RESULTS

All five trajectories showed an upward trend and rose faster after grade 2. Children in the sharp-developing (n = 44), high-developing (n = 136), and rapid-developing (n = 237) myopia groups developed myopia before grades 2, 3, and 4, respectively. Their SER development speed remained at a relatively high level after myopia, almost consistent with that before myopia. Children in the moderate-developing (n = 418) and low-developing (n = 391) non-myopia groups did not develop myopia before grade 4. Some characteristics in grade 1 were independently associated with SER trajectories, including sex, axial length, number of parents with myopia, residence, academic achievement, and the duration of outdoor activity. Based on the baseline characteristics, we established the model predicting the probability of children belonging to each group.

CONCLUSIONS

Myopia interventions are best started in grade 1 or preschool age. If interventions are not taken in time, the latest intervention window might be in grades 1, 2, and 3 for children with a high probability of belonging to the sharp-developing, high-developing, and rapid-developing myopia groups, respectively. The above probabilities might be predicted using the model we established. Moreover, the interventions for myopic children shouldn't be ignored.

Correlation between refractive errors and ocular biometric parameters in children and adolescents: a systematic review and meta-analysis

BACKGROUND

Refractive errors are one of the most common ocular conditions among children and adolescents, with myopia showing an increasing prevalence and early onset in this population. Recent studies have identified a correlation between refractive errors and ocular biometric parameters.

METHODS

A systematic search was conducted in electronic databases including PubMed, EMBASE, Cochrane Library, Web of Science, and Medline from January 1, 2012, to May 1, 2023. Various ocular biometric parameters were summarized under different refractive states, including axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), corneal curvature (CC), Corneal curvature radius (CR),axial length-to-corneal radius ratio (AL/CR ratio), choroidal thickness (ChT), retinal thickness (RT), retinal nerve fiber layer thickness (RNFL), and retinal blood density (VD). The differences in these parameters among different refractive states were analyzed using Stata software with fixed or random-effects models, taking into account the assessed heterogeneity level.

RESULTS

This meta-analysis included a total of 69 studies involving 128,178 eyes, including 48,795 emmetropic eyes, 60,691 myopic eyes, 13,983 hyperopic eyes, 2,040 low myopic eyes, 1,201 moderate myopic eyes, and 1,468 high myopic eyes. The results of our study demonstrated that, compared to the control group (emmetropic group), the myopic group and low, moderate, and high myopic groups showed significant increases in AL, AL/CR ratio, and ACD, while the hyperopic group exhibited significant decreases. Compared to the control group, the myopic group had a significantly increase for CC, while CR, CCT, perifoveal RT, subfoveal ChT, foveal ChT, parafoveal ChT, perifoveal (except nasal) ChT, and pRNFL (except temporal) significantly decreased. Compared to the control group, the hyperopic group had a significantly increase for subfoveal ChT, foveal ChT, parafoveal ChT, perifoveal ChT, and nasal pRNFL. Compared to the control group, the low and moderate myopic groups had a significantly decreases for the CCT, parafoveal RT (except nasal), perifoveal RT (except nasal), and pRNFL (except superior and temporal). Compared to the control group, the high myopic group had a significantly increase for CR, while LT, perifoveal ChT (except nasal), parafoveal RT, perifoveal RT, and pRNFL (except temporal) had significant decreased.

CONCLUSION

The changes of ocular biometric parameters in children and adolescents are closely related to refractive errors. Ocular biometric parameters devices, as effective non-invasive techniques, provide objective biological markers for monitoring refractive errors such as myopia.

Incidence and its risk factors of high myopia in Chinese rural adults: A population-based six-year cohort study

BACKGROUND

To investigate the incidence rate of high myopia and its risk factors in adults.

METHODS

This was a population-based cohort study, 4582 adults aged ≥ 30 years from rural area of China were included. The follow-up duration was six years. Objective refraction (sphere, cylinder, and axis) was measured using an autorefractor. Multivariable Logistic regression was used to explore risk factors of high myopia, odds ratio (OR) with 95% confidence interval (CI) were reported.

RESULTS

During the six-year follow-up, 25 participants developed high myopia. The incidence rate was 0.55% (95%CI: 0.44% to 0.66%), and were 0.54% (11/2035) in males and 0.55% (14/2547) in females. The age-gender standardized annual incidence rate was 0.11%. The median changes in spherical equivalent (SE) of all participants was 0.25D (IQR: -0.125 to 0.625). For the baseline myopic adults and non-myopic adults, the median changes in SE were 0.125D (IQR: -0.375 to 0.5), and 0.25D (IQR: -0.125 to 0.625). The difference was significant (p < 0.001). Of the two subgroups, 1.52% (21/1383) and 0.13% (4/3199) developed high myopia during six years. The risk of developing high myopia in baseline myopic adults was 11.7 times higher than that of the baseline non-myopic adults (p < 0.001). Age (OR = 1.061, 95%CI: 1.022 to 1.103, p = 0.002), and baseline myopia (OR = 1.007, 95%CI: 1.001 to 1.012, p < 0.001) were risk factors for high myopia.

CONCLUSION

The age-gender standardized annual incidence rate of high myopia in Chinese rural adults is 0.11%. More than 30% of adults still have myopia progression. Myopia control is of great significance for high myopia prevention.

Seagull wings appearance on optical coherence tomography: A case of peripapillary detachment in pathologic myopia

PURPOSE

To report the case of a patient who presented with a peripapillary retinal detachment caused by pathological myopia.

OBSERVATIONS

A 73-year-old female with a clinical history of high myopia was admitted to our ophthalmic department complaining of vision loss in her right eye. Her best-corrected visual acuity was 20/25 in the right eye and 20/400 in the left eye. The refractive error was -9.00 D in both eyes. The anterior segment and pupillary reflex were normal. Dilated fundus examination revealed myopic retinopathy in both eyes and a yellow peripapillary lesion, distinct from the myopic conus and encircling almost the whole optic disc, in her right eye. The left eye displayed macular atrophy with macular pigmentation due to a previous myopic choroidal neovascularization. Optical coherence tomography showed a localized retinal detachment in the peripapillary area, adjacent to the inferior edge of the optic disc, giving a strange "seagull wings" appearance.

CONCLUSIONS AND IMPORTANCE

In case of peripapillary neuroepithelial detachment the presence of PDPM in high myopic patients should always be excluded. Further research is due in order to better understand this clinical entity's pathogenesis and prognosis.

Six-month repeated irradiation of 650 nm low-level red light reduces the risk of myopia in children: a randomized controlled trial

PURPOSE

To evaluate whether the six-month repeated irradiation of 650 nm low-level red light (LLRL) decreases the risk of myopia onset in children.

METHODS

This was a single-masked, randomized controlled trial. A total of 112 children (aged 6-12 years) were enrolled and randomized to the treatment group or control group in a 1:1 ratio. The cycloplegic spherical equivalent error (SER) of children at baseline was -0.5 diopter (D) to 3D. Children in the treatment group were irradiated with the 650 nm LLRL for 6 min daily. No intervention was given to the control. The primary outcomes are myopia incidence, change in cycloplegic SER, and change in axial length (AL).

RESULTS

For the treatment group and control group, the six-month myopia incidence rates were 1.8% (95% confidence interval, CI: 0.2-4.9%) and 12.5% (95% CI: 5.5-21.9%), respectively. The difference was significant (p = 0.028). The median changes in AL for the treatment group and control group were -0.02 (interquartile range, IQR: -0.12 to 0.06) mm, and 0.09 (IQR: 0-0.18) mm, respectively. The difference was significant (p < 0.001). The median changes in cycloplegic SER for the treatment group and control group were 0 (IQR: 0-0.25) D, and -0.125 (IQR: -0.375 to 0) D, respectively. The difference was significant (p < 0.001). There was no adverse event.

CONCLUSION

The repeated irradiation of 650 nm LLRL may have a strong effect for myopia prevention in children, without risk of adverse events.

TRIAL REGISTRATION

this trial is retrospectively registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ), the registration number is ChiCTR2200058963.

Global risk factor analysis of myopia onset in children: A systematic review and meta-analysis

INTRODUCTION

This work aimed to comprehensively assess the risk factors affecting myopia in children to develop more effective prevention and treatment strategies. To this end, data from database were employed to assess the relationship between the incidence of myopia and its risk factors.

METHODS

We searched eight databases online in June 2022. Cohort studies were included that measured the connection between risk factors and myopia. Eligibility was not restricted by language. The Newcastle-Ottawa Scale (NOS) was used to measure the risk of bias and conducted GRADE evaluation to determine the certainty of evidence. Potential risk factors with positive or negative results were seen. Inplasy Registration: https://inplasy.com/inplasy-2022-4-0109/.

RESULTS

Evidence that risk factors for myopia are mixed, comprising both positive (20) and null (17) findings. In 19 cohort studies on 3578 children, girls were more likely to develop myopia (RR: 1.28 [1.22-1.35]). Myopia can occur at any age, from early childhood to late adulthood. Children whose parents had myopia were more likely to develop myopia. Longer outdoor activities time (RR: 0.97 [0.95-0.98]) and less near-work time (RR: 1.05 [1.02-1.07]) appeared to be significantly decrease the incidence of myopia. Children with lower SE, longer AL, a lower magnitude of positive relative accommodation, worse presenting visual acuity, deeper anterior chamber, and thinner crystalline lens may be related to myopia onset. The burden of myopia in underprivileged countries is higher than in developed countries (RR: 5.28 [2.06-13.48]). The quality of evidence for the evaluated factors was moderate to low or very low.

CONCLUSIONS

Genetic factors, environmental factors (such as excessive use of electronic products, and poor study habits) and lifestyle factors (such as lack of outdoor activities, poor nutrition, etc.) are the main risk factors for myopia in children. Myopia prevention strategies should be designed based on environmental factors, gender, parental myopia and eye indicators in order to explore a lifestyle that is more conducive to the eye health of children.

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

BACKGROUND

Schools 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.

METHODS

In 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.

RESULTS

From 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).

CONCLUSION

In 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.

Myopia Control Efficacy of Spectacle Lenses With Aspherical Lenslets: Results of a 3-Year Follow-Up Study

PURPOSE

To investigate myopia control efficacy in children who continued wearing spectacle lenses with highly aspherical lenslets (HAL) or switched from spectacle lenses with slightly aspherical lenslets (SAL) and single-vision spectacle lenses (SVL) to HAL for 1 year after a 2-year myopia control trial.

DESIGN

This was a 1-year extension of a randomized clinical trial.

METHODS

Of 54 children who had worn HAL for 2 years, 52 continued wearing HAL (HAL1 group), and of the 53 and 51 children who had originally worn SAL or SVL, 51 and 48 switched to wearing HAL (HAL2 and HAL3 groups) in year 3, respectively. A new SVL (nSVL) group of 56 children was recruited, matched for age, sex, cycloplegic spherical equivalent refraction (SER), and axial length (AL) of the HAL3 group at extension baseline, and used for a comparison of third-year changes. SER and AL were measured every 6 months in year 3.

RESULTS

During year 3, the mean (SE) myopia progression in the nSVL group was -0.56 (0.05) diopters (D). Compared with nSVL, the changes in SER were less in HAL1 (-0.38 [0.05] D, P = .02), HAL2 (-0.36 [0.06] D, P = .01), and HAL3 (-0.33 [0.06] D, P = .005). The mean (SE) AL elongation in the nSVL group was 0.28 (0.02) mm. Compared with nSVL, the elongation in AL was less in the HAL1 (0.17 [0.02] mm, P < .001), HAL2 (0.18 [0.02] mm, P < .001), and HAL3 (0.14 [0.02] mm, P < .001) groups. Myopia progression and axial elongation were comparable in all 3 HAL groups (all P > .05) in year 3.

CONCLUSIONS

Myopia control efficacy has remained in children who wore HAL in the previous 2 years. Children who switched from SAL or SVL to HAL in year 3 had slower myopia progression and axial elongation than that in the control group.

Prevalence and associated factors of myopia among school students in Shenyang, China: a cross-sectional study

Background

In recent years, the prevalence of myopia has increased significantly and caused great concern. Nevertheless, an estimate of myopia in the student population in Shenyang, Liaoning Province, China is still lacking. This study aims to determine the prevalence of myopia among students in Shenyang and investigate the associated factors affecting myopia development.

Methods

Standard logarithmic visual acuity chart and automatic computerized optometry under non-ciliary muscle paralysis were used to test the students' naked visual acuity of their right and left eyes. The included students were organized to fill in questionnaires on WeChat to collect the factors affecting myopia.

Results

A total of 34,644 students with a median age of 11.9 years were examined, including 17,563 males and 17,081 females. The overall prevalence of myopia was 60%, with a prevalence of 45% for mild myopia, 13% for moderate myopia, and 1.9% for high myopia. The sex, high educational stage, family history of myopia, doing homework after school or reading and writing for more than 2 h were associated with a higher risk of myopia, while doing eye exercises twice a day or more, going outdoors during recess, reading and writing with eyes more than one foot from books, and sleeping more than 8 h a day were associated factors for preventing myopia. The associated factors influencing myopia vary among different subgroups.

Conclusion

The prevalence of myopia in Shenyang is at a high level. In addition to sex, high educational stage and genetic factors, environmental factors including length of eye usage, eye exercises, outdoor activities, eye working distance, and sleep duration are associated with myopia prevalence. Therefore, it is recommended that the occurrence and development of myopia can be prevented by controlling the above environmental factors.

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.

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

PURPOSE

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.

METHODS

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.

RESULTS

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 ≥0.5 D, 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).

CONCLUSIONS

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.

Intraocular complement activation is related to retinal vascular and neuronal degeneration in myopic retinopathy

Purpose

To investigate the relationship between the intraocular levels of complement proteins and myopia-related retinal neuronal and vascular degeneration.

Methods

Aqueous humour from 147 myopic patients, including 60 low-myopia and 87 high-myopia were collected during Implantable Collamer Lens implantation surgery. All participants received comprehensive ophthalmic examinations, including logMAR best corrected visual acuity, axial length measurement, fundus photography and ocular B-scan ultrasonography. The myopic eyes were further classified into simple myopia (SM, n = 78), myopic posterior staphyloma (PS, n = 39) and PS with myopic chorioretinal atrophy (PS + CA, n = 30). Retinal thickness and vascular density in the macula (6 mm × 6 mm) and optic nerve head (4.5 mm × 4.5 mm) were measured using Optical Coherence Tomography (OCT) and OCT angiography (OCTA). The levels of complement proteins including C1q, C3, C3b/iC3b, C4, CFB, CFH, C2, C4b, C5, C5a, CFD, MBL and CFI in the aqueous humour were measured using the Luminex Multiplexing system. The real-time RT-PCR was conducted to examine the expression of complement genes (C1q, C2, C3, C4, CFI and CFD) in the guinea pig model of long-term form deprivation-induced myopic retinal degeneration.

Results

OCTA showed that retinal neuronal thickness and vascular density in superficial and deep layers of the macular zone as well as vascular density in the optic nerve head were progressively decreased from SM to PS and PS + CA (p < 0.05). The aqueous humour levels of C1q, C3, C3b/iC3b, C4, CFB, CFH, C2, C4b, C5 and CFI were significantly higher in high-myopic eyes compared to those in low-myopic eyes. Further subgroup analysis revealed the highest levels of complement components/fragments in the PS + CA group. The intraocular levels of complement factors particularly C3b/iC3b and C4 were negatively correlated with macular zone deep layer retinal thickness and vascular density and optic nerve head vascular density. The expression of C2, C3 and C4 genes was significantly higher in guinea pig eyes with myopic retinal degeneration compared to control eyes.

Conclusions

The intraocular classical pathway and alternative pathway of the complement system are partially activated in pathological myopia. Their activation is related to the degeneration of retinal neurons and the vasculature in the macula and the vasculature in the optic nerve head.

Prevalence of myopia among senior students in Fenghua, Eastern China, before and during the COVID-19 pandemic

Background

Myopia is a common cause of vision impairment worldwide. In China, the prevalence, the affected population, and the onset age of myopia are prominent issues. Prevention and intervention of myopia are great public health concerns.

Methods

This school-based retrospective study retrieved visual acuity and refractive data of senior students (grade 12th) from six high schools in Fenghua City, Zhejiang Province, eastern China, from 2016 and 2022. Noncycloplegic autorefraction was performed for refractive status. Students were divided into three subgroups by their school types. The overall myopia prevalence, as well as the prevalence of low myopia, moderate myopia, and high myopia, were calculated separately for each year. Statistical analyzes were performed using SPSS 25.0 and Graphpad Prism software.

Results

The mean myopia prevalence in Fenghua was 84.5% (95% CI: 84.0-85.0%), and a slightly downward trend was found in myopia prevalence after 2019, but the change was not statistically significant (p = 0.078). The overall prevalence of myopia was 79.6, 85.2, and 86.1% in vocational high schools, general high schools, and key high schools, respectively, with statistically significant differences (p < 0.001). The prevalence of myopia among senior students in the vocational high school was significantly lower than that in the other two high schools. There's no significant change in the overall prevalence of myopia (84.7% vs. 84.3%, p = 0.265) before and during the COVID-19 pandemic, and it remained statistically insignificant after stratifying by gender (male p = 0.207, female p = 0.918) or school types (vocational high school p = 0.112; general high school p = 0.299; key high school p = 0.393).

Conclusion

The prevalence of myopia among senior students in Fenghua is relatively high, and the COVID-19 pandemic has no significant impact on it. The prevalence of myopia among vocational high school students is lower than that of general high school and key high school. Attention should be paid to the effects of educational pressure on the prevalence of myopia among students.

IMI 2023 Digest

Myopia is a dynamic and rapidly moving field, with ongoing research providing a better understanding of the etiology leading to novel myopia control strategies. In 2019, the International Myopia Institute (IMI) assembled and published a series of white papers across relevant topics and updated the evidence with a digest in 2021. Here, we summarize findings across key topics from the previous 2 years. Studies in animal models have continued to explore how wavelength and intensity of light influence eye growth and have examined new pharmacologic agents and scleral cross-linking as potential strategies for slowing myopia. In children, the term premyopia is gaining interest with increased attention to early implementation of myopia control. Most studies use the IMI definitions of ≤-0.5 diopters (D) for myopia and ≤-6.0 D for high myopia, although categorization and definitions for structural consequences of high myopia remain an issue. Clinical trials have demonstrated that newer spectacle lens designs incorporating multiple segments, lenslets, or diffusion optics exhibit good efficacy. Clinical considerations and factors influencing efficacy for soft multifocal contact lenses and orthokeratology are discussed. Topical atropine remains the only widely accessible pharmacologic treatment. Rebound observed with higher concentration of atropine is not evident with lower concentrations or optical interventions. Overall, myopia control treatments show little adverse effect on visual function and appear generally safe, with longer wear times and combination therapies maximizing outcomes. An emerging category of light-based therapies for children requires comprehensive safety data to enable risk versus benefit analysis. Given the success of myopia control strategies, the ethics of including a control arm in clinical trials is heavily debated. IMI recommendations for clinical trial protocols are discussed.

IMI-Onset and Progression of Myopia in Young Adults

Myopia typically starts and progresses during childhood, but onset and progression can occur during adulthood. The goals of this review are to summarize published data on myopia onset and progression in young adults, aged 18 to 40 years, to characterize myopia in this age group, to assess what is currently known, and to highlight the gaps in the current understanding. Specifically, the peer-reviewed literature was reviewed to: characterize the timeline and age of stabilization of juvenile-onset myopia; estimate the frequency of adult-onset myopia; evaluate the rate of myopia progression in adults, regardless of age of onset, both during the college years and later; describe the rate of axial elongation in myopic adults; identify risk factors for adult onset and progression; report myopia progression and axial elongation in adults who have undergone refractive surgery; and discuss myopia management and research study design. Adult-onset myopia is common, representing a third or more of all myopia in western populations, but less in East Asia, where onset during childhood is high. Clinically meaningful myopia progression continues in early adulthood and may average 1.00 diopters (D) between 20 and 30 years. Higher levels of myopia are associated with greater absolute risk of myopia-related ocular disease and visual impairment, and thus myopia in this age group requires ongoing management. Modalities established for myopia control in children would be options for adults, but it is difficult to predict their efficacy. The feasibility of studies of myopia control in adults is limited by the long duration required.

The Causal Effect of Education on Myopia: Evidence That More Exposure to Schooling, Rather Than Increased Age, Causes the Onset of Myopia

Purpose

To distinguish the effects of age and grade on the development of myopia.

Methods

Grade 1 (n = 1465, mean age 6.71 ± 0.29 years; 53.5% male) and Grade 2 students (n = 1381, mean age 7.76 ± 0.30 years; 52.5% male) were examined in 2018, with a follow-up examination in 2019. Cycloplegic spherical equivalent (SE) in diopter (D) was measured. Regression discontinuity (RD) analysis was used to assess the causal effects on refraction at each visit.

Results

The sample in a grade was divided into three 4-month age blocks according to their birth month, the youngest, middle, and the oldest. At the 2018 visit, within each grade, there were no significant differences in SE among age blocks (all P > 0.05), despite an age range of 12 months. However, comparing the youngest block in Grade 2 to the oldest block in Grade 1, an average age difference of four months, a significant difference in SE was found (0.82 ± 0.69 D vs. 1.05 ± 0.55 D, t-test P < 0.01). Formal RD analysis found a significant casual effect of grade increase on myopic refraction shift (β = -0.32 D; 95% CI, -0.73 to -0.01; P = 0.042). Consistent results were found using the 2019 data.

Conclusions

Increased grade, rather than increasing age, is the major cause of myopic shifts in refraction. A causal link implies that interventions aimed at reducing the myopigenic exposures experienced during a school year have the potential to markedly reduce the myopic shifts in refraction associated with a grade of schooling.

Extreme myopia is more susceptible to SOX2 gene than high myopia

PURPOSE

To explore the association between two single-nucleotide polymorphisms (SNPs) in the SOX2 gene and high and extreme myopia in the Han Chinese population.

MATERIALS AND METHODS

A genetic association study using a case-control method was performed with 139 high myopia, 318 extreme myopia, and 918 healthy participants from the Chinese Han population. Two SNPs (rs4459940 and rs4575941) near SOX2 gene were selected for genotyping. We compared the allelic frequencies and haplotypes of the SNPs to assess their association with high and extreme myopia. This study was adjusted for sex and age of participants in the groups.

RESULT

The mean ages of the extreme myopia and control subjects were 47.44 ± 15.59 and 44.15 ± 14.08 years, respectively. The rs4575941 SNP of the SOX2 gene and the GG and AG genotypes showed no significant association with the risk of high myopia as opposed to the AA genotype (GG, OR = 0.94, 95% CI = 0.55-1.60, P = 0.820, Pc = NS; AG, OR = 0.91, 95% CI = 0.54-1.52, P = 0.708, Pc = NS). However, the frequency of the risk G allele of rs4575941 was significantly higher in the extreme myopia group than in the control group (OR = 1.31, 95% CI = 1.08-1.59; P = 0.007; Pc = 0.014). Furthermore, there were significant differences in the GG genotype frequency between the extreme myopia and control groups (OR = 1.77, 95% CI = 1.45-2.74, P = 0.009, Pc = 0.036). The A-G haplotype frequency was higher in the extreme group (OR = 1.27, 95% CI = 1.05-1.55, P = 0.014), while there were no significant differences found in high myopia group (OR = 1.18, 95% CI = 0.77-1.31, P = 0.979).

CONCLUSION

The SOX2 rs4575941 polymorphism, in Chinese Han population, contributes to the susceptibility of extreme myopia. SOX2 may thus be implicated in extreme myopia rather than in high myopia.

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.

[Recommendations for Progressive Myopia in Childhood and Adolescence. Statement of the DOG, BVA and the Bielschowsky Society for Strabismus Research and Neuroophthalmology - Status June 2022]

Since the last and at the same time first statement of the German ophthalmological societies on the possibilities of reducing myopia progression in childhood and adolescence, many new details and aspects have emerged in clinical research. This second statement updates the previous document and specifies the recommendations on visual and reading behavior as well as on pharmacological and optical therapy options, which have been both refined and newly developed in the meantime.

[Recommendations for progressive myopia in childhood and adolescence. Statement of the DOG, BVA and the Bielschowsky Society for Strabismus Research and Neuroophthalmology : Status June 2022]

Since the last and at the same time first statement of the German ophthalmological societies on the possibilities of reducing myopia progression in childhood and adolescence, many new details and aspects have emerged in clinical research. This second statement updates the previous document and specifies the recommendations on visual and reading behavior as well as on pharmacological and optical therapy options, which have been both refined and newly developed in the meantime.

Development and Validation of a Model to Predict Who Will Develop Myopia in the Following Year as a Criterion to Define Premyopia

PURPOSE

To develop and validate models to predict who will develop myopia in the following year based on cycloplegic refraction or ocular biometry and to identify thresholds of premyopia.

METHODS

Prospective longitudinal data of nonmyopic children at baseline from the Guangzhou Twins Eye Study and the Guangzhou Outdoor Activity Longitudinal Study were used as the training set, and the Singapore Cohort Study of the Risk factors for Myopia study formed the external validation set. Age, sex, cycloplegic refraction, ocular biometry, uncorrected visual acuity, and parental myopia were integrated into 3 logistic regression models to predict the onset of myopia in the following year. Premyopia cutoffs and an integer risk score system were derived based on the identified risk.

RESULTS

In total, 2896 subjects with at least 2 visits were included. Cycloplegic refraction at baseline is a better predictor to identify the children with myopia onset [C-statistic=0.91, 95% confidence interval (CI), 0.87-0.94; C-statistic=0.92, 95% CI, 0.92-0.92 for internal and external validation, respectively], comparing to axial length, corneal curvature radius (CR) and anterior chamber depth (C-statistic=0.81, 95% CI, 0.73-0.88; C-statistic=0.80, 95% CI, 0.79-0.80, respectively), and axial length/CR (C-statistic=0.78, 95% CI, 0.71-0.85; C-statistic=0.76, 95% CI, 0.75-0.76). With a risk of >70%, the definitions of premyopia indicating approaching myopia onset were 0.00 D for 6-8 years and -0.25 D for ≥9 years in children with 2 myopic parents.

CONCLUSIONS

Either cycloplegic refraction or ocular biometry can predict 1-year risk of myopia. Premyopia can be successfully defined through risk assessments based on children's age and predict who would require more aggressive myopia prophylaxis.

Role of tutorial classes and full day schooling on self-reported age of myopia onset: findings in a sample of Argentinian adults

PURPOSE

To investigate the effect of tutorial classes and schooling schedule in childhood on age of myopia onset.

METHODS

Refractive data for subjects ≥18 years of age were collected from 8 dispensing opticians or refractive ophthalmologists' offices in Argentina. Age of myopia onset, spherical equivalent (SE), and risk factors were determined using questionnaires. Multiple linear regression models were applied to assess possible factors associated with age of myopia onset or final adult SE.

RESULTS

A total of 274 adults (61.3% females) with myopia between -0.50 and -6.00 D were included. Mean age was 36.9 ± 14.5 years. The mean adult SE was -2.95 ± 1.45 D, and the mean age of myopia onset was 14.2 ± 5.4 years. Subjects that attended after-school tutorial classes (β = -2.23; P = 0.005) or a full day schedule in primary school (β = -1.07; P = 0.035) or that spent more time on near work (β = -0.70; P = 0.010) in childhood, had younger age of myopia onset.

CONCLUSIONS

In our study cohort, adults that had attended tutorial classes and/or full-day schooling during childhood had younger age of myopia onset.

Success Rate of Swept-Source Optical Coherence Tomography Biometry of Eyes of Elementary School Students

PURPOSE

To determine the success rate of swept-source optical coherence tomography (SS-OCT) biometry (OA-2000) in elementary school students.

METHODS

This was a prospective observational longitudinal study of 115 right eyes of elementary school students who were 8- to 9-years-old at the initial examination. Biometric measurements of the eyes were performed annually for three years, viz., during the third, fourth, and fifth grades. The success rates of obtaining data from optical biometric measurements of the axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), pupillary diameter (PD), corneal diameter (CD), and corneal curvature (CC) were determined.

RESULTS

The AL, CCT, and CC could be measured in all images at the three measurement times in all subjects. The success rate of the measurements of the ACD was 92.2% in the third grade and 100% in the fourth and fifth grade. The LT was successfully measured in 88.7% in the third grade, 99.1% in the fourth grade, and 100% in the fifth grade. The PD was successfully measured in 100% of the third grade, 96.0% of the fourth grade, and 100% in the fifth grade. The CD was successfully measured in 84.3% in the third grade, 66% in the fourth grade, and 100% in the fifth grade.

CONCLUSION

SS-OCT can obtain accurate measures of all ocular parameters in the primary school students with high success rates. However, care should be taken especially in analyzing the ACD, LT, PD, and CD because errors can occur in some cases.

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.

Characteristics of the Optic Nerve Head in Myopic Eyes Using Swept-Source Optical Coherence Tomography

Purpose

To investigate the characteristics of the optic nerve head (ONH) in myopia using swept-source optical coherence tomography (SS-OCT).

Methods

Participants were divided into three groups according to the axial length (AL). The optic disc morphology, retinal nerve fiber layer (RNFL) thickness, and radial peripapillary capillary (RPC) vessel density (VD), optic disc tilt, rotation, Bruch's membrane opening distance (BMOD), border length (BL), border tissue angle, focal lamina cribrosa (LC) defects, β- and γ-zone peripapillary atrophy (PPA), microvasculature dropout (MvD), choroidal thickness (CT), and the choroidal vascularity index (CVI) were compared. Linear regression analysis evaluated relationships between spherical equivalent, AL, and ONH parameters.

Results

One hundred five, 98, and 118 eyes were included in groups 1, 2, and 3, respectively. With AL increasing, the mean, superior and temporal CT, central mean and temporal, pericentral mean, inferior and nasal RPC VD, and temporal CVI decreased, whereas the mean and temporal RNFL thickness, optic disc, RIM and β-PPA area, presence and area of γ-PPA, BMOD and BL increased. Compared to other groups, group 3 depicted a larger cup area, more focal LC defect and total and juxtapapillary MvD; a lower central superior, inferior and nasal, pericentral superior, and temporal RPC VD. Group 1 demonstrated more tilted disc, larger inferior and nasal CT, mean, superior, inferior, and nasal CVI.

Conclusions

Myopia eyes have larger ONH changes, PPAs, regional RNFL, and MvD, but smaller regional CTs, RPC VD, and CVIs. SS-OCT may be useful in detecting ONH variations during myopia.

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.