EPIDEMIC OF PATHOLOGIC MYOPIA: What Can Laboratory Studies and Epidemiology Tell Us?

Effects of physical activity patterns on myopia among children and adolescents: A latent class analysis

BACKGROUND

The daily physical activity (PA) patterns of children and adolescents are intricate and ambiguous, with varying effects on myopia resulting from different combinations of PA. This study aims to scrutinize the spectrum of PA patterns among children and adolescents and assess their impact on myopia.

METHODS

Data sourced from the 2014 National Student Physical Fitness Survey (Tianjin segment) encompassed PA records and visual acuity measurements of participants. Latent Class Analysis and a generalized linear model were employed to investigate the relationship between PA categories and visual acuity across different educational stages.

RESULTS

The study comprised 6465 primary and middle school students, among whom 50.13% were male. PA patterns were categorized into high (27.16%), medium (29.88%) and low visual acuity regulation groups (13.97%) and the nonmainstream group (28.99%). Following adjustments for sex, age, region and BMI, the medium visual acuity regulation group exhibited a lower risk of myopia (OR = 0.617, 95% CI = 0.424-0.897, p = 0.012; OR = 0.654, 95% CI = 0.438-0.976, p = 0.038) compared to the nonmainstream group among junior and senior middle school students.

CONCLUSION

The efficacy of diverse PA patterns in mitigating myopia risk varies across educational stages and is influenced by sex-specific factors. It is imperative to advance myopia management strategies by emphasizing tailored PA interventions, discerning between PA patterns and delivering timely guidance and interventions tailored to distinct educational stages and sexes.

Tessellated fundus occurs earlier than myopia in children aged 3-6 years

BACKGROUND/OBJECTIVES

Tessellated fundus can exist in normal healthy eyes. This study aims to evaluate the occurrence and influencing factors of tessellated fundus in preschool children aged 3-6 years.

SUBJECTS/METHODS

This kindergarten-based cross-sectional study included 1716 children with an age range of 3-6 years. All participants underwent a comprehensive eye examination and a questionnaire. According to the number of quadrants occupied by tessellated fundus around the optic disc in fundus photographs, it was divided into four grades.

RESULTS

600 (35.0%) children had peripapillary tessellation. According to the spherical equivalent (SE), the subjects were divided into three groups: Hyperopia group (SE > + 0.75D, n = 1194)；Pre-myopia group (-0.50D < SE ≤ + 0.75D, n = 455); Myopia group (SE ≤ -0.50D, n = 67). The proportion of peripapillary tessellated fundus was 33.0%, 38.0%, 50.7% respectively. According to the regression analysis, in the non-myopia group (Pre-myopia group and Hyperopia group), the occurrence of peripapillary tessellated fundus was associated with longer axial length (OR, 1.566; 95% CI: 1.229-1.996, p < 0.001) and larger corneal radius of curvature (OR, 1.837; 95% CI: 1.006-3.354, p = 0.048). However, in Pre-myopia group, the corneal radius of curvature was not associated with the occurrence of peripapillary tessellated fundus (p = 0.830). In Hyperopia group, the corneal radius of curvature was associated with the occurrence of peripapillary tessellated fundus (OR, 2.438; 95% CI: 1.160-5.122, p = 0.019).

CONCLUSIONS

The occurrence of peripapillary tessellated fundus is more than 30% in 3-6 year old preschool children. Tessellated fundus can also occur in non-myopic children, and is related to the length of axial length and large radius of corneal curvature.

Differential Impact of 0.01% and 0.05% Atropine Eyedrops on Ocular Surface in Young Adults

Purpose

To evaluate the effect of low-concentration (0.01% and 0.05%) atropine eyedrops on ocular surface characteristics in young adults.

Methods

Twenty-six myopic students aged 18 to 30 years were randomly assigned to receive either 0.01% or 0.05% atropine once nightly for 14 days, followed by cessation, with a ≥14-day interval between each administration. Assessments were conducted one, two, seven, and 14 days after using atropine with corresponding timepoints after atropine cessation. Tear meniscus height and first and average noninvasive keratograph tear film breakup time (NIKBUT-first, NIKBUT-average) were measured using Keratograph 5M, whereas the objective scatter index (OSI) was measured by OQAS II devices; the ocular surface disease index (OSDI) score was also obtained.

Results

The mean OSI peaked after two days of administration of 0.05% atropine (β = 0.51, P = 0.001), accompanied by significant decreases in NIKBUT-first (β = -7.73, P < 0.001) and NIKBUT-average (β = -8.10, P < 0.001); the OSDI peaked after 14 days (β = 15.41, P < 0.001). The above parameters returned to baseline one week after atropine discontinuation (all P > 0.05). NIKBUT-first and NIKBUT-average reached their lowest points after 14 days of 0.01% atropine administration (NIKBUT-first: β = -4.46, P = 0.005; NIKBUT-average: β = -4.42, P = 0.001), but those significant changes were diminished once atropine treatment stopped.

Conclusions

Young adult myopes experienced a significant but temporary impact on the ocular surface with 0.05% atropine administration, whereas 0.01% atropine had a minimal effect.

Translational Relevance

The investigation of the ocular surface effects of different concentrations of atropine may inform evidence-based clinical decisions regarding myopia control in young adults.

Longitudinal analysis of refraction and ocular biometrics in preschool children with early-onset high myopia

We investigated changes in refraction and ocular biometrics in preschool children with early-onset high myopia. Sixty eyes of 60 children with a mean follow-up time of 58.5 months were included in this study. At baseline, mean age of children was 55.6 ± 13.1 months, mean spherical equivalent (SE) was - 8.59 ± 2.66 D, and 25.64 ± 1.16 mm for axial length (AL). The total annual rate of myopic progression and axial elongation were - 0.37 ± 0.39 D/year and 0.33 ± 0.18 mm/year, respectively. During follow-up period, there was a trend toward less myopic progression and axial elongation over time. Of the total participants, 24 children (40%) were in the myopia progression group and the remaining 36 children (60%) were in the myopia stability group. In multiple linear regression analysis, baseline SE and AL were independently associated with myopic progression, while age, sex, and baseline AL-to-CR ratio were not related to myopic progression. According to the model, more myopic SE (β = - 0.186, P = 0.035) and longer AL (β = - 0.391, P = 0.008) at baseline were significantly associated with myopic progression. Myopia progression in preschoolers with high myopia tended to be relatively modest, with 60% of subjects exhibited myopic stability. Higher myopic SE, and longer AL at baseline were associated with myopic progression in preschool children with high myopia.

RNA-Sequencing Analysis Reveals the Role of Mitochondrial Energy Metabolism Alterations and Immune Cell Activation in Form-Deprivation and Lens-Induced Myopia in Mice

Myopia is a substantial global public health concern primarily linked to the elongation of the axial length of the eyeball. While numerous animal models have been employed to investigate myopia, the specific contributions of genetic factors and the intricate signaling pathways involved remain incompletely understood. In this study, we conducted RNA-seq analysis to explore genes and pathways in two distinct myopia-inducing mouse models: form-deprivation myopia (FDM) and lens-induced myopia (LIM). Comparative analysis with a control group revealed significant differential expression of 2362 genes in FDM and 503 genes in LIM. Gene Set Enrichment Analysis (GSEA) identified a common immune-associated pathway between LIM and FDM, with LIM exhibiting more extensive interactions. Notably, downregulation was observed in OxPhos complex III of FDM and complex IV of LIM. Subunit A of complex I was downregulated in LIM but upregulated in FDM. Additionally, complex V was upregulated in LIM but downregulated in FDM. These findings suggest a connection between alterations in energy metabolism and immune cell activation, shedding light on a novel avenue for understanding myopia's pathophysiology. Our research underscores the necessity for a comprehensive approach to comprehending myopia development, which integrates insights from energy metabolism, oxidative stress, and immune response pathways.

Changes of dysfunctional lens index before and after implantable collamer lens V4c implantation in patients with moderate-to-high myopia

BACKGROUND

Dysfunctional lens index (DLI) changing is rarely reported after implantable collamer lens (ICL) implantation. In the current research, we hope to investigate the changes of DLI by ray-tracing aberrometry before and after implantation of the posterior chamber phakic implantable collamer lens with a central artificial hole for patients with moderate-to-high myopia.

METHODS

This retrospective, observational case series included 206 eyes of 104 patients with moderate-to-high myopia who underwent ICL V4c implantation. Data were collected on ocular indicators preoperatively and at 1 day, 1, 3, and 6 months postoperatively. The i-Trace Visual Functional Analyzer was used to assess the DLI measurement.

RESULTS

The overall values of safety index and efficacy index were both more than 1. Preoperatively, the mean spherical equivalent (SE) of included 206 eyes was - 10.77 ± 3.46 diopter (D). Then at 1-day postoperation, the mean SE was - 0.22 ± 0.55 D, and barely changed from 1 day to 6 months postoperatively. Although the endothelial parameters had no significant differences between preoperation and postoperation, the mean loss of endothelial cells was 0.74 ± 0.98% at 6 months. Regarding the vault, there was a significant difference between each time of follow-up (P < 0.001). The mean of the vault decreased 109.6 ± 13.5 µm from 1-day post-op to 6 months post-op. The DLI values were 3.70, 9.26, 10.00, and 9.68 at baseline, 1, 3, and 6 months, respectively (P < 0.001), but no significant differences were found between 1, 3, and 6 months postoperatively (P > 0.05). The preoperative lnDLI showed a significant positive linear correlation (r = 0.621, P < 0.001) with the preoperative spherical equivalent (SE). The lnDLI was negatively correlated with the axial length (r = - 0.462, P < 0.001), corneal thickness (r = - 0.207, P = 0.003), preoperative LogMAR UDVA (r = - 0.189, P = 0.006), and preoperative LogMAR CDVA (r = - 0.306, P < 0.001).

CONCLUSIONS

The postoperative refractive parameters were confirmed excellent in efficacy, predictability, and stability in half a year. The DLI was significantly improved after the ICL V4c implantation in patients with moderate-to-high myopia and showed good stability during the follow-up periods. The DLI deserves a more comprehensive understanding and application in clinical services.

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.

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.

Longitudinal Changes in Axial Length and Spherical Equivalent in Children and Adolescents With High Myopia

Purpose

To investigate longitudinal changes in axial length (AL) and spherical equivalent (SE) in children and adolescents with high myopia and to explore associated risk factors.

Methods

This was a longitudinal, observational cohort study of highly myopic participants (aged 7-17 years) to evaluate the mean rates of change in AL and SE. Mixed effects regression models were used to explore the risk factors.

Results

The sample consisted of 293 participants (mean age at the baseline, 13.63 ± 2.66 years; mean AL, 27.03 ± 1.30 mm diopters; mean SE, -8.99 ± 2.30 diopters) who were followed for 7.09 ± 1.64 years. Pathological myopia (PM) was present in 11.95% of the participants at the baseline. Over the follow-up period, the mean AL and SE progression rates were 0.13 mm/y (95% CI, 0.12-0.14) and -0.36 diopters/y (95% CI, -0.39 to -0.34). The multivariate analysis showed that the AL elongation and myopic SE progression decreased significantly after age 11 (β = -0.080, P < 0.001; β = 0.146, P < 0.001), increased with a greater baseline SE (β = -0.006, P = 0.014; β = 0.017, P = 0.005), and accelerated in children and adolescents who had PM at the baseline (β = 0.043, P = 0.011; β = -0.097, P = 0.025).

Conclusions

A significant association was found between acceleration of AL elongation and myopic SE progression among the children and adolescents with age, especially those younger than 11 years, and the presence of PM.

Are we facing an increasing surgical demand for high myopic traction maculopathies? A 12-year study from Hong Kong

PURPOSE

We aimed to investigate the longitudinal change in the number of surgically operated myopic traction maculopathies (MTM) cases at a tertiary eye centre.

METHODS

A retrospective study of all consecutive cases of surgically operated MTM over 12 years (2009-2020) was conducted in a myopia prevalent region. We compared outcomes among three groups: (1) myopic macular hole (MH), (2) myopic macular hole with retinal detachment (MHRD), and (3) myopic foveoschisis with retinal detachment (MFRD).

RESULTS

Fifty-one cases were included in the study (8 cases of MH, 33 cases of MHRD and 10 cases of MFRD). The overall mean age was 63.8 +/- 8.7 with a female preponderance (2:1). The mean age of the MH group (58.6) was significantly younger than the MHRD group (64.2) and MFRD group (66.6) (p = 0.02). Subgroup analysis using ATN classification did not show its correlation with both visual improvement and anatomical success. When comparing the first 6-year period (2009-2014) with the second 6-year period (2015-2020), there was a significant increase in the number of cases (p = 0.01).

CONCLUSION

We observe an increase in the number of surgically operated MTM. This follows the trend of the global rise in the prevalence of myopia and baby boomers entering retirement.

Myopia and Near Work: A Systematic Review and Meta-Analysis

BACKGROUND

Myopia is a global public health problem affecting quality of life and work productivity. Data is scarce regarding the effects of near work on myopia. Providing a larger meta-analysis with life-long perspective, including adults and occupational exposure seemed needed.

METHODS

We searched PubMed, Cochrane Library, Embase and Science Direct for studies reporting myopia prevalence in near work. Myopia was defined as a mean spherical equivalent ≤ -0.50 diopter. We performed a meta-analysis using random-effects model on myopia prevalence, myopia progression per year, and odds ratio (OR) of myopia in near work, completed by subgroup analyses and meta-regressions on patients' characteristics, type of work in adults, geographic zones, time and characteristics of near work.

RESULTS

We included 78 studies, representing a total of 254,037 participants, aged from 6 to 39 years. The global prevalence of myopia in near work was 35% (95% CI: 30 to 41%), with a prevalence of 31% (95% CI: 26 to 37%) in children and 46% (95% CI: 30 to 62%) in adults. Myopia progression was -0.39 diopters per year (-0.53 to -0.24 D/year), ranging from -0.44 (-0.57 to -0.31) in children to -0.25 D/year (-0.56 to 0.06) in adults. The odds of myopia in workers exposed vs. non-exposed to near work were increased by 26% (18 to 34%), by 31% (21 to 42%) in children and 21% (6 to 35%) in adults. Prevalence of myopia was higher in adults compared to children (Coefficient 0.15, 95% CI: 0.03 to 0.27).

CONCLUSIONS

Near work conditions, including occupational exposure in adults, could be associated with myopia. Targeted prevention should be implemented in the workplace.

Effect of Text Messaging Parents of School-Aged Children on Outdoor Time to Control Myopia: A Randomized Clinical Trial

IMPORTANCE

Myopia in school-aged children is a public health issue worldwide; consequently, effective interventions to prevent onset and progression are required.

OBJECTIVE

To investigate whether SMS text messages to parents increase light exposure and time outdoors in school-aged children and provide effective myopia control.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted in China from May 2017 to May 2018, with participants observed for 3 years. Of 528 965 primary school-aged children from Anyang, 3113 were randomly selected. Of these, 268 grade 2 schoolchildren were selected and randomly assigned to SMS and control groups. Data were analyzed from June to December 2021.

INTERVENTIONS

Parents of children in the SMS group were sent text messages twice daily for 1 year to take their children outdoors. All children wore portable light meters to record light exposure on 3 randomly selected days (2 weekdays and 1 weekend day) before and after the intervention.

MAIN OUTCOMES AND MEASURES

The co-primary outcomes were change in axial length (axial elongation) and change in spherical equivalent refraction (myopic shift) from baseline as measured at the end of the intervention and 3 years later. A secondary outcome was myopia prevalence.

RESULTS

Of 268 grade 2 schoolchildren, 121 (45.1%) were girls, and the mean (SD) age was 8.4 (0.3) years. Compared with the control group, the SMS intervention group demonstrated greater light exposure and higher time outdoors during weekends, and the intervention had significant effect on axial elongation (coefficient, 0.09; 95% CI, 0.02-0.17; P = .01). Axial elongation was lower in the SMS group than in the control group during the intervention (0.27 mm [95% CI, 0.24-0.30] vs 0.31 mm [95% CI, 0.29-0.34]; P = .03) and at year 2 (0.39 mm [95% CI, 0.35-0.42] vs 0.46 mm [95% CI, 0.42-0.50]; P = .009) and year 3 (0.30 mm [95% CI, 0.27-0.33] vs 0.35 mm [95% CI, 0.33-0.37]; P = .005) after the intervention. Myopic shift was lower in the SMS group than in the control group at year 2 (-0.69 diopters [D] [95% CI, -0.78 to -0.60] vs -0.82 D [95% CI, -0.91 to -0.73]; P = .04) and year 3 (-0.47 D [95% CI, -0.54 to -0.39] vs -0.60 D [95% CI, -0.67 to -0.53]; P = .01) after the intervention, as was myopia prevalence (year 2: 38.3% [51 of 133] vs 51.1% [68 of 133]; year 3: 46.6% [62 of 133] vs 65.4% [87 of 133]).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, SMS text messages to parents resulted in lower axial elongation and myopia progression in schoolchildren over 3 years, possibly through increased outdoor time and light exposure, showing promise for reducing myopia prevalence.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR-IOC-17010525.

A Comparative Study on Visual Health and Physical Activity of Chinese and Japanese Children Aged 6-12 Years

OBJECTIVES

In this study, we compare the visual acuity levels and physical activity participation of Chinese and Japanese children.

METHODS

We collected data on static visual acuity, kinetic visual acuity, axial length, intensity, frequency, duration, amount, and physical activity items of 431 children aged 6-12 years from Chinese and Japanese schools in the same city. Our analysis examined the relationships involving age, visual function indicators, ocular biometric parameters, and extracurricular physical activity.

RESULTS

We found the myopia rate higher in Chinese children than in Japanese children, increasing with age except in grade 4; kinetic visual acuity in Chinese children was lower than in Japanese children (p<.01). The axial length becomes longer with age in both groups, with Chinese children having a longer axial length than Japanese children. The amount of physical activity in Chinese and Japanese children aged 6-12 years fluctuates. The frequency, duration, and physical activity items are lower in Chinese children than Japanese (p<.01).

CONCLUSIONS

Chinese and Japanese children's overall static visual acuity development level shows a decreasing trend, and Japanese children have better kinetic visual acuity and physical activity participation than Chinese children. Physical activity could have an impact on visual acuity.

Ocular biometric parameters of mild hyperopia to mild myopia children aged 6-14 years from Wenzhou optometry center: A cross-sectional study

Introduction

Myopia is the most common visual disorder in school-aged children and adolescents worldwide. This study aimed to explore the ocular biometric characteristics of children aged 6–14 years from the Wenzhou optometry center and to determine the relationship between spherical equivalent refraction (SER) and macular pigment optical density (MPOD).

Subjects and methods

Participants underwent a full-scale ophthalmic examination anteriorly and posteriorly. Relevant parameters were documented, such as axial length (AL), anterior chamber depth (ACD), SER and lens thickness (LT), corneal curvature radius (CCR), and MPOD. Lens power (LP) was calculated using Bennett’s formula. Shapiro–Wilk tests and histograms were used to check the normality of the distribution of refractive and ocular biometric parameters. Scatter diagrams were adopted to analyze the relationships between refraction and parameters of ocular biometry. Multiple linear regression models were employed to fit the associated factors of AL, AL/CCR, and LP.

Results

A total of 902 mild hyperopia to mild myopia (+3.00 D ≤ SE ≤ −3.00 D) children aged 6–14 years were included. The mean age of participants was 10.03 ± 2.47 years, and the prevalence of mild hyperopia, emmetropia, and myopia was 5.65, 27.05, and 67.30%, respectively. The prevalence of mild myopia increased from 30.53% at 6 years of age to 93.62% at 14 years of age. Overall, AL, ACD, and AL/CCR increased, but LP declined from 6 to 14 years of age, whereas CCR and MPOD remained stable. An increase of 1 mm in AL was associated with −0.69 D of myopic change. A unit increase in AL/CCR was associated with −7.87 D in SER. As for the SER variance, AL explained 30.5% and AL/CCR explained 51.1%, whereas AL/CCR and LP accounted for 59.2%.

Discussion

In this work, we have studied the distributions of ocular biometric characteristics of mild hyperopia to mild myopia children from the perspective of an optometry center rather than a sampling survey. In addition, we found that children from the optometry center had a slower progression toward myopia than those from previous sampling surveys, which was an informative finding for future myopia prevention. In addition, we have made a correlation analysis between the macular pigment optical density and spherical equivalent refraction. Though, no correlation was found.

Rural-urban differences in prevalence of and risk factors for refractive errors among school children and adolescents aged 6-18 years in Dalian, China

Purpose

To assess the prevalence of refractive errors (REs) in school children aged 6-18 years in urban and rural settings in Dalian, Northeast of China.

Methods

This is a school-based cross-sectional survey using multi-stage randomization technique. Six- to eighteen-year-old school children from elementary schools, junior and senior high schools from a rural area and an urban area in Dalian were included in December 2018. All subjects underwent a comprehensive questionnaire and eye examination.

Results

A total of 4,522 school children with 6-18 years of age were investigated. The age, gender-adjusted prevalence of myopia, and anisometropia were 82.71 and 7.27% among the urban students as compared to 71.76% and 5.41% among the rural ones (OR = 1.80, 95 % CI = 1.53 - 2.11, P < 0.001; OR = 1.29, 95 % CI = 1.00-1.67, P = 0.049), respectively. The hyperopia was less common in urban students than in rural ones (5.63 vs. 10.21%; OR = 0.54, 95 % CI: 0.43-0.67, P < 0.001). However, there was no significant difference in prevalence of astigmatism between urban (46.07%) and rural (44.69%) participants (OR = 0.96, 95 % CI: 0.84-1.10, P = 0.559). The differences on prevalence of REs were attributed to different social-demographic and physiologic factors.

Conclusions

The students from urban settings are more likely to have myopia and anisometropia but less likely to have hyperopia than their rural counterparts. Although considerable attention had been paid to controlling REs, it is necessary to further consider the urban-rural differences in REs.

Sports and Myopia: An Investigation on the Prevalence and Risk Factors of Myopia in Young Sports-Related Groups in Tianjin, China

Objective

To explore the relationship between sports and the prevalence of myopia in young sports-related groups in Tianjin, China.

Methods

In this cross-sectional study, a cluster sampling method was used to survey professional athletes in Tianjin, students at Tianjin University of Sport, and Tianjin Vocational College of Sports. All participants completed epidemiological questionnaires and ophthalmic examinations. Multivariable logistic regression models were used to explore the potential risk factors of myopia.

Results

This study recruited 1401 participants. The prevalence of myopia was 50.18%. The prevalence of low, moderate, and high myopia were 52.63%, 37.41%, and 9.96%, respectively. There were no sex-related differences in the prevalence of myopia. The odds of having myopia was 1.788 times higher in the indoor sports group than the outdoor sports group (the adjusted odds ratio [OR], 95% confidence interval [CI], 1.391–2.297). Training time of more than 4 h/d (4–6 h/d: OR, 0.539; 95% CI, 0.310–0.938; >6 h/d: OR, 0.466; 95% CI, 0.257–0.844) resulted in a lower risk of myopia. Participants who often used the electronic screen (OR, 1.406; 95% CI, 1.028–1.923) and/or had a family history of myopia (OR, 2.022; 95% CI, 1.480–2.763) were more likely to suffer from myopia.

Conclusions

Outdoor sports do not necessarily guarantee to insulate against myopia. Youngsters engaged in outdoor sports had a lower prevalence of myopia than those participating in indoor sports. Electronic screen use, training time, and family history of myopia were also associated with the prevalence of myopia in young sports-related groups.

Topography-Guided FS-LASIK With PAE Algorithm and Sirius Tomography Data for Correction of Myopia and Myopic Astigmatism

PURPOSE

To compare the clinical outcomes after topography-guided and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) planned with the Phorcides Analytic Engine (PAE) algorithm system and Sirius tomography data for correction of myopia and myopic astigmatism when the ocular residual astigmatism (ORA) was great or not.

METHODS

In this retrospective study, a total of 163 eyes with myopia and myopic astigmatism (99 patients) were included. Eyes with myopic astigmatism and high ORA of 0.75 diopters (D) or greater were assigned to the high ORA group and the others to the low ORA group. All surgeries were performed by topography-guided FS-LASIK planned with a PAE algorithm system. PAE took anterior and posterior corneal negative cylinder of the 5-mm zone from the Sirius combined topography and tomography. Refractive and visual outcomes, vector analysis, and corneal aberrations were compared between the two groups.

RESULTS

At 6 months postoperatively, the uncorrected distance visual acuity of 20/16 or better was measured in 59% of eyes in the high ORA group and 66% of eyes in the low ORA group (P = .307). Postoperative corrected distance visual acuity, manifest refractive spherical equivalent, refractive astigmatism, target induced astigmatism, surgically induced astigmatism, and difference vector were similar between the two groups (P > .05). The postoperative corneal astigmatism was significantly higher in the high ORA group (P = .008), and the high ORA group over-corrected astigmatism with the rule and showed a higher correction index (P = .003) compared with the low ORA group.

CONCLUSIONS

Topography-guided FS-LASIK with PAE algorithm and Sirius combined topography and tomography data for correction of myopia and myopic astigmatism achieved the predicted surgical outcomes and there was a tendency to have a similar clinical outcome for PAE when the ORA was great or not. However, the PAE with high ORA overcorrected astigmatism with-the-rule and showed a higher correction index compared with the low ORA group. [J Refract Surg. 2022;38(4):235-242.].

Exposure to the Life of a School Child Rather Than Age Determines Myopic Shifts in Refraction in School Children

Purpose

The prevalence of myopia increases with both age and grade for children attending school. The current study aimed to distinguish the effects of aging and grade on myopia.

Methods

Grade 1 students (706 at baseline in 2009, mean age 6.56 ± 0.29 years, range 6.00 to 6.99 years old, 55.5% boys) were followed up until 2012. Cycloplegic spherical equivalent (SE) was measured annually.

Results

The sample in a grade was divided into three 4-month age blocks according to their birth month. Within each grade, there were no significant differences in SE between age blocks (all P > 0.05), despite an age range of one year. More myopic SE was observed in the youngest block of grade 2 compared to the oldest block of grade 1 (difference, -0.36 ± 0.08 D; P < 0.001), although age of the two blocks only differed by four months. Similarly, more myopic SE were found in the youngest block in grade 3 than the oldest block in grade 2 (differences, -0.50 ± 0.10 D; P < 0.001) and in the youngest block in grade 4 than the oldest block in grade 3 (differences, -0.82 ± 0.14 D; P < 0.001).

Conclusions

Exposure to schooling, rather than age, appears to be the major driver of refractive development, at least in the early years of schooling. Interventions during this period, involving reductions in educational pressure and increased time outdoors may have major effects on the subsequent development of myopia.

China Turns to School Reform to Control the Myopia Epidemic: A Narrative Review

ABSTRACT

Myopia is now a major public health issue in parts of East and Southeast Asia, including mainland China. In this region, around 80% of students completing 12 years of school education are now myopic, and from 10% to 20% have high myopia in excess of -6D. Interventions to prevent the onset of myopia based on increasing time outdoors have now been implemented at a system-wide scale in Chinese Taipei (Taiwan) and Singapore with some success, but the prevalence of myopia still remains high by international standards. In mainland China, until recently, myopia prevention was largely based on eye exercises, but these have not been sufficient to prevent an epidemic. Control of myopia progression with atropine eye drops has been widely practiced in Singapore and Taiwan, with recent practice concentrating on low-dose concentrations. Orthokeratology has also been widely used across the region. Recent research has produced both contact and spectacle lenses that slow myopia progression by imposing myopic defocus. The new approaches to myopia control are ready for systematic use, which may be facilitated by system-wide screening and referral. In recent years, renewed emphasis has been placed on the prevention of myopia in mainland China by China's President Xi Jinping. In addition to making use of all the measures outlined above, China now seems to be aiming for major reforms to schooling, reducing educational pressures, particularly in the early school years, freeing more time for outdoor play and learning. These new initiatives may be crucial to myopia prevention and control.

Progression Patterns of Myopic Traction Maculopathy in the Fellow Eye After Pars Plana Vitrectomy of the Primary Eye

Purpose

This retrospective study investigated the patterns and risk factors of progression of myopic traction maculopathy (MTM) of fellow eyes after pars plana vitrectomy (PPV) of primary eyes.

Methods

The study population comprised 153 patients with MTM in both myopic eyes who sequentially underwent PPV (2006–2021). Observation periods were from PPV of the primary eye (baseline) to PPV of the fellow (end). MTM was graded based on optical coherence tomography (OCT) images and the ATN (atrophy [A], traction [T], and neovascularization [N]) system. An increase in T grade was considered MTM progression.

Results

MTM progressed in 43.8% of fellow eyes during 34.57 ± 34.08 months. The progression of fellow eyes correlated with T grade of primary eyes (P < 0.001). Risk factors for the progression of MTM in fellow eyes were primary eyes in T4–T5, age at baseline <60 years, and fellow eyes with partial posterior vitreous detachment (PVD; P < 0.001, P = 0.042, and P = 0.002, respectively). Fellow eyes in T1/T2 at baseline progressed faster compared with those in T0 (P < 0.001); the annual rate of progression to T3–T5 of the T0 (T1–T2) groups was 9.98% (24.59%).

Conclusions

Risk factors for the progression of MTM in fellow eyes included PPV when relatively young, primary eye at high T grade, and partial PVD of the fellow eye. Personalized follow-up for fellow eyes should be based on the severity of MTM of both eyes.

AI-Model for Identifying Pathologic Myopia Based on Deep Learning Algorithms of Myopic Maculopathy Classification and "Plus" Lesion Detection in Fundus Images

Background: Pathologic myopia (PM) associated with myopic maculopathy (MM) and “Plus” lesions is a major cause of irreversible visual impairment worldwide. Therefore, we aimed to develop a series of deep learning algorithms and artificial intelligence (AI)–models for automatic PM identification, MM classification, and “Plus” lesion detection based on retinal fundus images.

Materials and Methods: Consecutive 37,659 retinal fundus images from 32,419 patients were collected. After excluding 5,649 ungradable images, a total dataset of 32,010 color retinal fundus images was manually graded for training and cross-validation according to the META-PM classification. We also retrospectively recruited 1,000 images from 732 patients from the three other hospitals in Zhejiang Province, serving as the external validation dataset. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy, and quadratic-weighted kappa score were calculated to evaluate the classification algorithms. The precision, recall, and F1-score were calculated to evaluate the object detection algorithms. The performance of all the algorithms was compared with the experts’ performance. To better understand the algorithms and clarify the direction of optimization, misclassification and visualization heatmap analyses were performed.

Results: In five-fold cross-validation, algorithm I achieved robust performance, with accuracy = 97.36% (95% CI: 0.9697, 0.9775), AUC = 0.995 (95% CI: 0.9933, 0.9967), sensitivity = 93.92% (95% CI: 0.9333, 0.9451), and specificity = 98.19% (95% CI: 0.9787, 0.9852). The macro-AUC, accuracy, and quadratic-weighted kappa were 0.979, 96.74% (95% CI: 0.963, 0.9718), and 0.988 (95% CI: 0.986, 0.990) for algorithm II. Algorithm III achieved an accuracy of 0.9703 to 0.9941 for classifying the “Plus” lesions and an F1-score of 0.6855 to 0.8890 for detecting and localizing lesions. The performance metrics in external validation dataset were comparable to those of the experts and were slightly inferior to those of cross-validation.

Conclusion: Our algorithms and AI-models were confirmed to achieve robust performance in real-world conditions. The application of our algorithms and AI-models has promise for facilitating clinical diagnosis and healthcare screening for PM on a large scale.

The Correlations between Horizontal and Vertical Peripheral Refractions and Human Eye Shape Using Magnetic Resonance Imaging in Highly Myopic Eyes

The aim of this study was to determine the relationship between relative peripheral refraction and retinal shape by 2-D magnetic resonance imaging in high myopes. Thirty-five young adults aged 20 to 30 years participated in this study with 16 high myopes (spherical equivalent < −6.00 D) and 19 emmetropes (+0.50 to −0.50 D). An open field autorefractor was used to measure refractions from the center out to 60° in the horizontal meridian and out to around 20° in the vertical meridian, with a step of 3 degrees. Axial length was measured by using A-scan ultrasonography. In addition, images of axial, sagittal, and tangential sections were obtained using 2-D magnetic resonance imaging. The highly myopic group had a significantly relative peripheral hyperopic refraction and showed a prolate ocular shape compared to the emmetropic group. The highly myopic group had relative peripheral hyperopic refraction and showed a prolate ocular form. Significant differences in the ratios of height/axial (1.01 ± 0.02 vs. 0.94 ± 0.03) and width/axial (0.99 ± 0.17 vs. 0.93 ± 0.04) were found from the MRI images between the emmetropic and the highly myopic eyes (p < 0.001). There was a negative correlation between the retina’s curvature and relative peripheral refraction for both temporal (Pearson r = −0.459; p < 0.01) and nasal (Pearson r = −0.277; p = 0.011) retina. For the highly myopic eyes, the amount of peripheral hyperopic defocus is correlated to its ocular shape deformation. This could be the first study investigating the relationship between peripheral refraction and ocular dimension in high myopes, and it is hoped to provide useful knowledge of how the development of myopia changes human eye shape.

Associations between BMI and visual impairment of 33 407 preschool children in Germany: a pooled cross-sectional study

BACKGROUND

Prevalence of overweight and obesity in Germany is increasing. High body weight can affect children's growth and development. This paper aimed to determine the association between body mass index (BMI) and visual impairment among preschool children and explore the potential role of obesity in predicting visual developmental disorder.

METHODS

Six consecutive years of data from the School Entry Examination were collected for all preschool children aged from 4 to 6 years residing in Rhine-Neckar County and the City of Heidelberg, Germany from 2013 to 2018. Univariate and multivariate regression were used to analyze the complete data, multiple imputation was used to deal with missing data.

RESULTS

Among the group with an immigrant background, children with obesity [OR = 1.20, 99% (1.02-1.42)] were more likely to have visual impairment compared to those with normal body weight (P < 0.01) after adjusting for survey year, age, and gender of children, education and occupation of parents, screen time-frequency, whether a television was in their bedroom, and quality of preschool outdoor environment.

CONCLUSION

There were significant associations between obesity and visual impairment among German preschool children with immigrant backgrounds. Strategies to support vulnerable groups were needed across all regional schools.

CLINICAL CHARACTERISTICS OF EYES WITH DIFFERENT GRADES OF MYOPIC TRACTION MACULOPATHY: Based on the New Classification System

PURPOSE

To analyze clinical characteristics in eyes with myopic traction maculopathy (MTM).

METHODS

Nine hundred and ninety-one patients (1,334 eyes) with MTM, who visited Zhongshan Ophthalmic Center from January 2014 to December 2019, were involved. Myopic traction maculopathy was classified into six grades according to the new classification system: no macular schisis (T0), inner or outer foveoschisis (FS) (T1); inner and outer FS (T2), foveal detachment (T3), full-thickness macular hole (T4), and macular hole retinal detachment (T5).

RESULTS

Seven hundred and seventy-eight (58.32%) eyes were in T0, 157 (11.77%) in T1, 177 (13.27%) in T2, 129 (9.67%) in T3, 45 (3.37%) in T4, and 48 (3.67%) in T5. With the severity of MTM, age increased and the best-corrected visual acuity became worse (P < 0.001). However, no significant differences were found on spherical equivalent refraction or axial length among different grades of MTM (P > 0.05). Moreover, significant differences on best-corrected visual acuity, spherical equivalent refraction, axial length, and staphyloma rate existed between eyes with inner FS and eyes with outer FS (P < 0.01), but not between eyes with outer FS and eyes with both inner FS and outer FS (P > 0.05). Besides, significant differences were found on spherical equivalent refraction, axial length, and staphyloma rate between full-thickness macular hole with and without macular schisis (P < 0.001).

CONCLUSION

Spherical equivalent refraction and axial length were not correlated with the severity of MTM in this cohort. It might be preferable to categorize eyes with outer FS and eyes with both inner FS and outer FS as a same grade. Potential difference in the pathogenesis between full-thickness macular hole with and without macular schisis might exist.

IMI Pathologic Myopia

Pathologic myopia is a major cause of visual impairment worldwide. Pathologic myopia is distinctly different from high myopia. High myopia is a high degree of myopic refractive error, whereas pathologic myopia is defined by a presence of typical complications in the fundus (posterior staphyloma or myopic maculopathy equal to or more serious than diffuse choroidal atrophy). Pathologic myopia often occurs in eyes with high myopia, however its complications especially posterior staphyloma can also occur in eyes without high myopia.

Owing to a recent advance in ocular imaging, an objective and accurate diagnosis of pathologic myopia has become possible. Especially, optical coherence tomography has revealed novel lesions like dome-shaped macula and myopic traction maculopathy. Wide-field optical coherence tomography has succeeded in visualizing the entire extent of large staphylomas. The effectiveness of new therapies for complications have been shown, such as anti-VEGF therapies for myopic macular neovascularization and vitreoretinal surgery for myopic traction maculopathy.

Myopia, especially childhood myopia, has been increasing rapidly in the world. In parallel with an increase in myopia, the prevalence of high myopia has also been increasing. However, it remains unclear whether or not pathologic myopia will increase in parallel with an increase of myopia itself. In addition, it has remained unclear whether genes responsible for pathologic myopia are the same as those for myopia in general, or whether pathologic myopia is genetically different from other myopia.

IMI Risk Factors for Myopia

Risk factor analysis provides an important basis for developing interventions for any condition. In the case of myopia, evidence for a large number of risk factors has been presented, but they have not been systematically tested for confounding. To be useful for designing preventive interventions, risk factor analysis ideally needs to be carried through to demonstration of a causal connection, with a defined mechanism. Statistical analysis is often complicated by covariation of variables, and demonstration of a causal relationship between a factor and myopia using Mendelian randomization or in a randomized clinical trial should be aimed for. When strict analysis of this kind is applied, associations between various measures of educational pressure and myopia are consistently observed. However, associations between more nearwork and more myopia are generally weak and inconsistent, but have been supported by meta-analysis. Associations between time outdoors and less myopia are stronger and more consistently observed, including by meta-analysis. Measurement of nearwork and time outdoors has traditionally been performed with questionnaires, but is increasingly being pursued with wearable objective devices. A causal link between increased years of education and more myopia has been confirmed by Mendelian randomization, whereas the protective effect of increased time outdoors from the development of myopia has been confirmed in randomized clinical trials. Other proposed risk factors need to be tested to see if they modulate these variables. The evidence linking increased screen time to myopia is weak and inconsistent, although limitations on screen time are increasingly under consideration as interventions to control the epidemic of myopia.

Intra- and interobserver concordance of a new classification system for myopic maculopathy

BACKGROUND

Myopic maculopathy (MM) is one of the major causes of visual impairment and irreversible blindness in eyes with pathologic myopia (PM). However, the classification of each type of lesion associated with MM has not been determined. Recently, a new MM classification system, known as the ATN grading and classification system, was proposed; it is based on the fundus photographs and optical coherence tomography (OCT) images and includes three variable components: atrophy (A), traction (T), and neovascularization (N). This study aimed to perform an independent evaluation of interobserver and intraobserver agreement for the recently developed ATN grading system for MM.

METHODS

This was a retrospective study. Fundus photographs and OCT images of 125 patients (226 eyes) with various MMs were evaluated and classified using the ATN grading of the new MM classification system by four blinded and independent evaluators (2 attending ophthalmologists and 2 ophthalmic residents). All cases were randomly re-evaluated by the same observers after an interval of 6 weeks. The kappa coefficient (κ) and 95% confidence interval (CI) were used to determine the interobserver and intraobserver agreement.

RESULTS

The interobserver agreement was substantial when considering the maculopathy type (A, T, and N). The weighted Fleiss κ values for each MM type (A, T, and N) were 0.651 (95% CI: 0.602-0.700), 0.734 (95% CI: 0.689-0.779), and 0.702 (95% CI: 0.649-0.755), respectively. The interobserver agreement when considering the subtypes was good or excellent, except for stages A1, A2, and N1, in which the weighted κ value was less than 0.6, with moderate agreement. The intraobserver agreement of types and subtypes was excellent, with κ > 0.8. No significant differences were observed between the attending ophthalmologists and residents for interobserver reliability or intraobserver reproducibility.

CONCLUSIONS

The ATN classification allows an adequate agreement among ophthalmologists with different qualifications and by the same observer on separate occasions. Future prospective studies should further evaluate whether this classification can be better implemented in clinical decision-making and disease progression assessments.

Clinical efficacy of 0.01% atropine in retarding the progression of myopia in children

PURPOSE

To investigate the clinical efficacy of 0.01% atropine in slowing the progression of myopia in children and to evaluate the influence of 0.01% atropine on secretion of basal tear and stability of tear film.

METHODS

Eighty children aged 5-14 years with myopia, 40 were randomly divided into two groups consisting of those who received spectacles in addition to 0.01% atropine (SA group) and those who received only spectacles (S group). The remaining 40 children who were wearing orthokeratology (OK) lenses for 3 months were randomly divided into two groups comprising those who received OK lenses in addition to 0.01% atropine (OKA group) and those who received only OK lenses (OK group). Comprehensive ophthalmologic examinations, including slit-lamp examination, visual acuity testing, autorefraction, intraocular pressure, axial length (AL), corneal topography, Schirmer's test, and tear film break-up time (TBuT), were performed before treatment and after every 3 months treatment.

RESULTS

During the follow-up visits, evidently better spherical equivalent (SE) control over 3, 6 and 12 months was observed in the SA and OKA groups compared with the S and OK groups. The AL over 3, 6, and 12 months was evidently inhibited in the SA and OKA groups compared with the S and OK groups. No statistically significant differences in Schirmer's test and TBuT results were observed between the S and SA groups and between the OK and OKA groups. However, statistically significant differences were found in TBuT results between before treatment and after 3 months treatment in the OK group (P < 0.05, paired t test) and the OKA group (P < 0.05, paired t test).

CONCLUSIONS

0.01% atropine can effectively control myopia progression and axial elongation regardless of combined treatment with spectacles or OK lenses. And 0.01% atropine has no evident effect on Schirmer's test and TBuT results; however, researchers also found that Schirmer's test and TBuT results showed a tendency to reduce after treatment with 0.01% atropine.

Crosstalk between EP2 and PPARα Modulates Hypoxic Signaling and Myopia Development in Guinea Pigs

Purpose

Cyclic adenosine monophosphate (cAMP) and peroxisome proliferator-activated receptor alpha (PPARα) levels mediate extracellular matrix (ECM) changes by altering the levels of hypoxia-inducible factor 1-alpha (HIF-1α) in various tissues. We aimed to determine, in the sclera of guinea pigs, whether a prostanoid receptor (EP2)-linked cAMP modulation affects PPARα and HIF-1α signaling during myopia.

Methods

Three-week-old guinea pigs (n = 20 in each group), were monocularly injected with either an EP2 agonist (butaprost 1 µmol/L/10 µmol/L), an antagonist (AH6809 10 µmol/L/30 µmol/L) or a vehicle solution for two weeks during normal ocular growth. Separate sets of animals received these injections and underwent form deprivation (FD) simultaneously. Refraction and axial length (AL) were measured at two weeks, followed by scleral tissue isolation for quantitative PCR (qPCR) analysis (n = 10) and cAMP detection (n = 10) using a radioimmunoassay.

Results

Butaprost induced myopia development during normal ocular growth, with proportional increases in AL and cAMP levels. FD did not augment the magnitude of myopia or cAMP elevations in these agonist-injected eyes. AH6809 suppressed cAMP increases and myopia progression during FD, but had no effect in a normal visual environment. Of the diverse set of 27 genes related to cAMP, PPARα and HIF-1α signaling and ECM remodeling, butaprost differentially regulated 15 of them during myopia development. AH6809 injections during FD negated such differential gene expressions.

Conclusion

EP2 agonism increased cAMP and HIF-1α signaling subsequent to declines in PPARα and RXR mRNA levels, which in turn decreased scleral fibrosis and promoted myopia. EP2 antagonism instead inhibited each of these responses. Our data suggest that EP2 suppression may sustain scleral ECM structure and inhibit myopia development.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Efficacy in myopia control

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

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.

Myopia-related stepwise and quadrant retinal microvascular alteration and its correlation with axial length

PURPOSE

To investigate the characteristics of retinal vascular alterations in patients with varying degrees of myopia, and to determine correlated variables and alteration patterns over different retinal zones.

METHODS

A total of 208 right eyes of 208 patients with myopia were enrolled and divided into mild, moderate, high, and extreme myopia groups. The macular vasculature in superficial, deep, and whole retinal layers was imaged with optical coherence tomography angiography (OCTA). The vessel densities over the whole annular zone, four quadrants, and six annuli were quantified as fractal dimension using a customized software. Simple linear regressions and ridge regression were used to determine and compare explanatory variables of microvascular density.

RESULTS

The microvascular density within the superficial, deep and whole retinal layers was highest in mild myopia group, second highest in moderate myopia group, second lowest in high myopia group and lowest in extreme myopia group. Within the same layer, differences between any two groups were significant (all p < 0.05). Among the four quadrants, only the inferior nasal (IN) quadrant showed no difference in microvascular density between mild and moderate groups. Ridge regression indicated that microvascular density values in all three layers were more strongly correlated with axial length (AL) (scaled estimates -0.139, -0.103, -0.154; all p < 0.001) than with spherical equivalent (SE) (scaled estimates -0.052, -0.096, -0.057; all p < 0.05).

CONCLUSIONS

We characterized a stepwise and quadrant alteration of retinal microvascular density from mild to extreme myopia, which was more strongly affected by axial elongation, although both AL and SE were meaningful indicators.

Topical bendazol inhibits experimental myopia progression and decreases the ocular accumulation of HIF-1α protein in young rabbits

PURPOSE

To investigate the inhibitory effect of bendazol on form-deprivation myopia (FDM) in rabbits as well as the underlying biochemical processes.

METHODS

Forty-eight 3-week-old New Zealand white rabbits were randomly assigned to three groups: a control group, a form-deprivation (FD) group and an FD + bendazol group (treated with 1% bendazol in the FD eyes). Refraction, corneal curvature, vitreous chamber depth (VCD) and axial length (AL) were assessed using streak retinoscopy, keratometry, and A-scan ultrasonography, respectively. Eyeballs were enucleated for histological analysis, and ocular tissues were homogenized to determine the mRNA and protein expression of hypoxia-inducible factor-1α (HIF-1α) and muscarinic acetylcholine receptors (mAChRs).

RESULTS

Bendazol inhibited the progression of FDM and suppressed the upregulation of HIF-1α. At week 6, in the control, FD and FD + bendazol groups, the refraction values were 1.38 ± 0.43, 0.03 ± 0.47 and 1.25 ± 0.35 D, respectively (p < 0.001); the ALs were 13.91 ± 0.11, 14.15 ± 0.06 and 13.97 ± 0.10 mm, respectively (p < 0.001) and the VCDs were 6.56 ± 0.06, 6.69 ± 0.07 and 6.61 ± 0.06 mm, respectively (p < 0.001). HIF-1α was upregulated in FD eyes but downregulated in FD + bendazol eyes, while the mAChRs were the opposite.

CONCLUSIONS

In the FD rabbit model, bendazol significantly inhibits the development of myopia and downregulates HIF-1α expression, which may provide a novel therapeutic approach for myopia control.

Progression and Longitudinal Biometric Changes in Highly Myopic Eyes

Purpose

To examine 2-year progression rate and associated biometric changes in highly myopic eyes.

Methods

This is a longitudinal, observational cohort study that included 657 participants aged 7 to 70 years with bilateral high myopia (≤-6.00 diopters [D]) and followed for 2 years. All participants underwent ocular biometry and cycloplegic refraction examinations. Main outcome measures were changes in spherical equivalent refraction (SE) and ocular biometry in the right eyes.

Results

Mean age of participants was 21.6 ± 12.2 years. At baseline, mean SE was -9.82 ± 3.28 D and ocular biometric measurements were 27.40 ± 1.56 mm for axial length, 3.16 ± 0.27 mm for anterior chamber depth, 3.60 ± 0.35 mm for lens thickness, and 20.09 ± 1.50 mm for vitreous chamber depth. After 2 years of follow-up, there was a trend toward more myopia and greater axial elongation in all age groups. Younger participants (≤20 years) had significantly (P < 0.001) greater rates of myopic shift and axial elongation compared with older participants (>20 years). However, highly myopic adults aged 40 to 70 years continued to demonstrate refractive progression, particularly if they had extremely high myopia (≤-10.00 D). In the multiple regression analysis, each additional diopter of myopia at baseline was associated with a 11% higher risk of a >1.00-D/y myopic shift (odds ratio, 1.11; 95% confidence interval, 1.04-1.18; P = 0.002).

Conclusions

Longitudinal data from this large Chinese cohort suggest that highly myopic eyes continue to progress in SE throughout life, with the greatest rates of progression observed in younger participants. Axial elongation rates appeared to stabilize after 20 years of age and were predominantly due to an increase in the vitreous chamber depth. Other risk factors for a myopic shift included a higher degree of myopic refraction at baseline.

Comparisons of surgical outcomes after epiretinal membrane peeling in the myopic eyes with long to that with normal axial length

PURPOSE

To compare the outcomes of vitrectomy with removal of an idiopathic epiretinal membrane (ERM) in the myopic eyes with long axial length (AL) to that in the eyes with normal AL.

METHODS

This was a retrospective, observational, case-control study. Fifty-six eyes of 56 patients with an idiopathic ERM were studied. Twenty-eight of these eyes had an axial length longer than 26.0 mm (Group A), and the other 28 eyes had axial lengths < 26.0 mm (Group B). The age and visual acuity of the two groups were not significantly different. All subjects were treated by vitrectomy and peeling of the ERM with a 25- or 27-gauge system. The postoperative best-corrected visual acuity (BCVA) and optical coherence tomographic findings were determined at 3 and 6 months postoperatively.

RESULTS

The mean BCVA improved from 0.35 ± 0.25 to 0.15 ± 0.25 logMAR units in the eyes with the long AL and from 0.35 ± 0.25 to 0.10 ± 0.21 logMAR units in the eyes with normal AL at 6 months postoperatively (both P < 0.001). The postoperative BCVA was not significantly different between the two groups at 6 months (P = 0.221). The central macula was thinner in the eyes of Group A than Group B (P < 0.001). The restorations of the ellipsoid zone and the external limiting membrane were observed in both groups, but the interdigitation zone was less frequently restored in Group A (P < 0.001).

CONCLUSIONS

Vitrectomy with the removal of the epiretinal membrane is effective in attaining a good BCVA even in the myopic eyes with long AL.

The Effect of 0.01% Atropine Eye Drops on the Ocular Surface in Children for the Control of Myopia-The Primary Results from a Six-Month Prospective Study

Purpose

To evaluate the effect of 0.01% atropine eye drops on the ocular surface in children for the control of myopia.

Methods

A total of 72 participants were recruited for this prospective study. Prior to and after 1, 3, and 6 months of 0.01% atropine administration, an ocular surface disease index (OSDI) questionnaire was obtained, Keratograph 5M was used for the measurement of the tear meniscus height (TMH), noninvasive keratographic tear film break-up time (NK-BUT, the first keratographic break-up time, [NK-BUT_first] and the average keratographic break-up time, [NK-BUT_ave]), bulbar redness (BR), meiboscore (MS), and anterior segment optical coherence tomography (AS-OCT) was used to calculate the inferior tear meniscus area (TMA).

Results

After using the 0.01% atropine eye drops for 1 month, 9 subjects complained of discomfort immediately after administration, but this quickly subsided, and 1 subject was temporarily dazzled. All the ocular surface symptoms were mild and occurred rarely. After 3 months, these complaints no longer occurred. Compared with the baseline values, the OSDI scores (0.08 ± 0.28), values of TMH (0.23 ± 0.04 mm), TMA (0.0420 ± 0.0444 mm²), NK-BUT_first (9.39 ± 5.25 s), NK-BUT_ave (10.49 ± 4.94 s), BR (0.63 ± 0.37), and MS (0.89 ± 0.70) did not change significantly after 6 months of 0.01% atropine eye drop administration (P > 0.05).

Conclusion

In this 6-month prospective study, no side effects were observed on the ocular surface after using 0.01% atropine in children.

The Combined Effect of Low-dose Atropine with Orthokeratology in Pediatric Myopia Control: Review of the Current Treatment Status for Myopia

Pediatric myopia has become a major international public health concern. The prevalence of myopia has undergone a significant increase worldwide. The purpose of this review of the current literature was to evaluate the peer-reviewed scientific literature on the efficacy and safety of low-dose atropine treatment combined with overnight orthokeratology for myopia control. A search was conducted in Pubmed and Web of Science with the following search strategy: (atropine OR low-dose atropine OR 0.01% atropine) AND (orthokeratology OR ortho-k) AND (myopia control OR myopia progression). All included studies improved myopia control by the synergistic effect of orthokeratology with low-dose atropine, compared with orthokeratology treatment alone. All studies included a short or medium follow-up period; therefore longer-term studies are necessary to validate these results.

Accommodation is unrelated to myopia progression in Chinese myopic children

This study shows accommodative accuracy and distance accommodation facility in myopic children do not play a role in myopia progression. In 144 subjects, the monocular distance accommodative facility (DAF) and continuous accommodative stimulus-response curves (ASRCs) were measured at the enrolment. Retrospective and prospective refraction with regard to the enrolment visit were obtained from the outpatient database system based on noncycloplegic subjective spherical equivalent refraction (SER). The rate of myopic progression at enrolment was the first derivative of the Gompertz function, which was fitted with each subject's longitudinal refractive error data, including at least four records of SER with an interval of more than 6 months between each visit. A mixed linear model for multilevel repeated-measures data was used to explore the associations between the rate of myopia progression and accommodative parameters. The mean rate of myopia progression at enrolment was -0.61 ± 0.31 D/y with a mean age of 12.27 ± 1.61 years. By adjusting for age and SER, it was shown that the myopic progression rate was not associated with the accommodative lag (F = 0.269, P = 0.604), accommodative lag area (F = 0.086, P = 0.354), slope of ASRC (F = 0.711, P = 0.399), and DAF (F = 0.619, P = 0.432).

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

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

Impact of peripheral optical properties induced by orthokeratology lens use on myopia progression

The objective of the present retrospective comparative cohort study was to compare the impact of wearing glasses versus an orthokeratology (Ortho-K) lens on peripheral optical properties and myopia progression in a population of South Korean children. Participants included children with myopia, between 8 and 12 years of age (n = 22 eyes), and divided into two groups: those who used glasses (Group I, n = 9) and those who used an Ortho-K lens (Group II, n = 13). Myopia progression over one year was quantified by changes in the central axial length of the eye. Keratometry and corneal aberrations on both the anterior and posterior surfaces of the eye were obtained using a Scheimpflug camera. A custom-developed Shack-Hartmann aberrometer was also used to measure peripheral aberrations across the horizontal visual field, up to 30°, and along the nasal-temporal meridian in 10-degree steps. Central axial elongation was larger in Group I (0.59 ± 0.21 mm) than in Group II (0.34 ± 0.18 mm) (P = .01). Relative peripheral spherical refractions at 10 and 20° nasally and at 10° temporally (P = 0.04, 0.049, and 0.042, respectively) relative to the fovea were positively correlated with central axial elongation in Group II. Group II exhibited an increase in peripheral ocular high order aberrations, such as horizontal coma and asymmetric trefoil. The use of Ortho-K lenses was found to slow the rate of central axis elongation in children with myopia. This effect might be related to an increase in both peripheral spherical refraction and peripheral ocular higher order aberrations with Ortho-K lens use.

Associations between near work, outdoor activity, parental myopia and myopia among school children in Aba, Nigeria

AIM

To assess the influence of near work, time outdoor and parental myopia on the prevalence of myopia in school children in Aba, Nigeria.

METHODS

Primary and secondary school children aged between 8 and 15y were randomly recruited from 12 schools in Aba. Information on family history, near work and outdoor activity was obtained using myopia risk factor questionnaire. Cycloplegic refraction was performed using autorefraction technique. Myopia was defined as spherical equivalent refraction (SER) ≤-0.50 D in the poorer eye. Data were analysed for 1197 (male: 538 and female: 659) children with full relevant data.

RESULTS

Risk of developing myopia was positively associated with parental myopia [odds ratio (OR): 6.80; 95%CI, 2.76-16.74; P<0.01) for one myopic parent and (OR: 9.47; 95%CI, 3.88-23.13; P<0.01) for two myopic parents, longer daily reading hour (OR: 1.21; 95%CI, 1.03-1.42; P=0.02) and less time outdoors (OR: 0.8; 95%CI, 0.74-0.87; P<0.01).

CONCLUSION

Parental history of myopia is the most important risk factor associated with myopia. In addition, children with both parents being myopic has increased odds of developing myopia than those with one myopic parent. It is recommended therefore, that children spend more time outdoors as this could reduce the prevalence and progression of myopia.

Increased endogenous dopamine prevents myopia in mice

Experimental evidence suggests that dopamine (DA) modulates refractive eye growth. We evaluated whether increasing endogenous DA activity using pharmacological or genetic approaches decreased myopia susceptibility in mice. First, we assessed the effects of systemic L-3,4-dihydroxyphenylalanine (L-DOPA) injections on form deprivation myopia (FDM) in C57BL/6 J (WT^C57) mice. WT^C57 mice received daily systemic injections of L-DOPA (n = 11), L-DOPA + ascorbic acid (AA, n = 22), AA (n = 20), or Saline (n = 16). Second, we tested transgenic mice with increased or decreased expression of vesicular monoamine transporter 2 (VMAT2^HI, n = 22; WT^HI, n = 18; VMAT2^LO, n = 18; or WT^LO, n = 9) under normal and form deprivation conditions. VMAT2 packages DA into vesicles, affecting DA release. At post-natal day 28 (P28), monocular FD was induced in each genotype. Weekly measurements of refractive error, corneal curvature, and ocular biometry were performed until P42 or P49. WT^C57 mice exposed to FD developed a significant myopic shift (treated-contralateral eye) in AA (-3.27 ± 0.73D) or saline (-3.71 ± 0.80D) treated groups that was significantly attenuated by L-DOPA (-0.73 ± 0.90D, p = 0.0002) or L-DOPA + AA (-0.11 ± 0.46D, p = 0.0103). The VMAT2^LO mice, with under-expression of VMAT2, were most susceptible to FDM. VMAT2^LO mice developed significant myopic shifts to FD after one week compared to VMAT2^HI and WT mice (VMAT2^LO: -5.48 ± 0.54D; VMAT2^HI: -0.52 ± 0.92D, p < 0.05; WT: -2.13 ± 0.78D, p < 0.05; ungoggled control: -0.22 ± 0.24D, p < 0.001). These results indicate that endogenously increasing DA synthesis and release by genetic and pharmacological methods prevents FDM in mice.

DIFFUSE CHORIORETINAL ATROPHY IN CHINESE HIGH MYOPIA: The ZOC-BHVI High Myopia Cohort Study

PURPOSE

To explore the associations between diffuse chorioretinal atrophy (DCA) and age, sex, axial length, spherical equivalent, and best-corrected visual acuity (BCVA) among highly myopic eyes.

METHODS

This study included right eyes of 857 bilaterally highly myopic individuals from the ZOC-BHVI Cohort Study. Participants underwent examinations, including BCVA, ocular biometry, autorefraction, and color fundus photography. An Early Treatment Diabetic Retinopathy Study grid was applied on the fundus photographs to evaluate the location of DCA, which was graded into four categories (D0-D3). The characteristics and ocular biometry were compared between participants' eyes with and without DCA.

RESULTS

Diffuse chorioretinal atrophy was found in 177 (20.6%) eyes. The proportion of participants with DCA in age groups of 7 to 11, 12 to 18, 19 to 39, and ≥ 40 years old was 20.9%, 9.2%, 23.1%, and 52.9%, respectively. The proportion of DCA significantly increased with longer axial length and worse myopic spherical equivalent. Eyes with DCA had poorer BCVA (Snellen visual acuity 20/36, logarithm of minimal angle of resolution 0.26 ± 0.25) than those without DCA (Snellen visual acuity 20/23, logarithm of minimal angle of resolution 0.06 ± 0.14) (P < 0.001). The BCVA gradually declined as the lesion got closer to the fovea (P for trend < 0.001).

CONCLUSION

The proportion of DCA increased with older age, longer axial length, and more myopic spherical equivalent. Diffuse chorioretinal atrophy is a vision-threatening complication of high myopia where BCVA gradually worsens with foveal involvement.

Characteristics of Posterior Precortical Vitreous Pockets and Cloquet’s Canal in Patients with Myopia by Optical Coherence Tomography

Purpose

To describe the morphological features of posterior precortical vitreous pockets (PPVP) and Cloquet's Canal in patients with myopia using swept-source optical coherence tomography (SS OCT).

Methods

A total of 96 eyes of 51 volunteers (range, 5-18 years) were enrolled in this study, and all individuals underwent OCT (Optovue Inc., Fremont, CA, USA) examinations. From the collected PPVPs images, the widths and heights of the PPVPs were measured, and connections between PPVPs and Cloquet's Canal were identified. The PPVPs widths and heights, width:height ratios and proportions of connections were compared among different age (5-8, 9-14, 15-18 years), axial length (AL; 21-23, 23-25, 25-29 mm) and myopia groups (hyperopia, low to moderate myopia, high myopia); the group data were analyzed to determine their relationship with myopia.

Results

PPVPs were identified in 89 of 96 eyes; 6 eyes were excluded for poor image quality. The PPVPs width was positively correlated with age, especially in the low to moderate myopia group (F = 7.715, P = 0.001). There was a significant difference in the PPVPs height between the refractive error groups in the 9 to 14 years group (F = 4.905, P = 0.005). The PPVPs width:height ratio was different among the refractive error groups in the 9 to 14 years group (F = 3.335, P = 0.041) and among the different age groups in the low to moderate myopia group (F = 6.077, P = 0.004). A total of 22 eyes (22.4%) were identified as having a connection between the PPVP and Cloquet's Canal. The connections began to increase with AL at 5 to 8 years (χ2 = 7.363, P = 0.025).

Conclusions

PPVPs existed in most myopia patients from 5 to 18 years old. PPVPs width was positively correlated with age, especially in the low to moderate myopia group. PPVPs height decreased in the 9 to 14 years group with myopia. An imbalance in the horizontal and vertical enlargement of PPVP was the main feature in the 9- to 14-year-old group with myopia. The connections between the PPVP and Cloquet's Canal were associated with AL extension in the 5- to 8-year-old group.