The complex interactions of retinal, optical and environmental factors in myopia aetiology

Annual Trend of Myopia and High Myopia in Children in Japan: A Nationwide Claims Database Study

Purpose

To determine the prevalence and annual trend of the number of incident cases of myopia and high myopia in children.

Design

A nationwide, comprehensive claims database study.

Participants

Of 15 million children aged ≤14 years, those covered by the universal health insurance were included. The validation study of the claims-based definitions of myopia and high myopia was conducted using 14 654 individuals aged ≤14 years recruited from 11 diverse medical facilities.

Methods

This study comprises a national claims database analysis and a multicenter validation study. Data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which contains the nationwide health insurance claims data, were assessed. All individuals aged ≤14 years were reviewed, and children with existing and new onset of myopia or high myopia between January 2011 and December 2020 were identified. A validation study was conducted by reviewing electric medical records.

Main Outcome Measures

Prevalence of myopia as of October 1, 2020, and the annual number of incident cases during 2014 to 2020.

Results

According to the 2020 population census, there were 14 955 692 children aged ≤14 years. Among them, 5 498 764 patients had myopia on October 1, 2020, corresponding to a prevalence of 36.8%. The number of incident cases of myopia was highest at 8 years of age, increasing from 853.3 cases/person-year in 2015 to 910.7 cases/person-year in 2020. The prevalence of high myopia increased with age, peaking at 0.46% among children aged 10 to 14 years; the number of incident cases annually increased in 5- to 9-year-olds and 10- to 14-year-olds. In the year 2020, when the coronavirus disease 2019 pandemic occurred, a discontinuous increase in the number of incident cases of myopia was observed in children aged 8 to 11 years, not 12 to 14 years. The overall sensitivity and specificity of the claims-based definition for myopia were 88.5% and 79.2%, respectively, whereas the corresponding values for high myopia were 41.6% and 99.8%.

Conclusions

This first comprehensive nationwide study revealed the prevalence and annual incidence trends of myopia and high myopia. These findings complement the results of previous high-quality cohort studies, offering a more comprehensive understanding of myopia trends.

Financial Disclosures

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

The burden of refraction disorders in 204 countries and territories from 1990 to 2021: A systematic analysis from the global burden of disease 2021

Background

Refraction disorders are common eye conditions that cause blurred vision and, if left uncorrected, remain a leading cause of moderate to severe visual impairment worldwide. Despite this, a comprehensive assessment of the associated burden is lacking. This study aims to describe and predict the burden and regional distribution of refraction disorders using data from the 2021 Global Burden of Disease (GBD) study.

Methods

This study utilized data from the Global Burden of Disease (GBD) 2021 on refraction disorders from 1990 to 2021. We analyzed the prevalence and disability-adjusted life years (DALYs) of refraction disorders and calculated the corresponding average annual percentage changes (AAPCs) in different gender and age groups across 204 countries and territories and 21 geographical regions. We employed the Bayesian Age-Period-Cohort (BAPC) model to predict the future burden of refraction disorders.

Results

From 1990 to 2021, the global age-standardized prevalence rate (ASPR) of refraction disorders decreased from 2053.56 (per 100000, 95% Uncertainty Interval [UI]: 1835.31 to 2275.80) to 1919.66 (per 100000, 95%UI: 1715.24 to 2135.28), with an average annual percentage change (AAPC) of -0.21% (95% Confidence Interval [CI]: -0.23% to -0.19%). The age-standardized DALY (Disability-Adjusted Life Years) rate also declined from 88.04 (per 100000, 95%UI: 62.19 to 125.15) to 79.11 (per 100000, 95%UI: 54.94 to 114.14) with an AAPC of -0.33% (95%CI: -0.36% to -0.31%). Refraction disorders remain a significant burden in regions with lower Socio-demographic Index (SDI), particularly in parts of South Asia and Western Sub-Saharan Africa. Older individuals and females are disproportionately affected. The age-standardized DALY rate is expected to decline steadily before stabilising at approximately 77.94 per 100000 by 2030.

Conclusions

From 1990 to 2021, the disease burden of refraction disorders showed a declining trend, but the decrease was not substantial. In some low-middle SDI regions, the burden remains high. Moreover, globally, women bear a higher burden than men. This study provides important information for the treatment and prevention of refraction disorders.

Changes in eye axis length and corneal curvature in central China from the perspective of birth year

OBJECTIVES

To explore the changes in eye structures over time in the Chinese population from the perspective of birth year.

METHODS

We collected measurement data of intraocular lens Master from patients who underwent intraocular lens Master biometry for a routine cataract or refractive examination (ametropia and presbyopia) between April 2012 and October 2023, then screened them. Selected patients were divided into ten groups of 10 years each according to their year of birth (called birth decades). Birth-year-dependent changes in axial length and corneal curvature were compared between the groups.

RESULTS

The average axial length increased from 23.52 mm to 25.95 mm, and the corneal curvature dropped from 44.20 D to 43.33 D in patients born in before-1930 and 1990s. The proportion of short average axial length and steep corneal curvature decreased, whereas the proportion of long average axial length increased with the birth decade. The proportion of patients with corneal curvature < 40 D was 4.18% in 1970s, 5.73% in 1980s, and 3.38% in 1990s, which were significantly higher than those of other age groups. The average axial length of the eyes among primary school students was 23.96 mm, and among college students, it was 25.86 mm.

CONCLUSIONS

Overall, with the birth decade, average axial length increased and corneal curvature decreased. There were generational differences in ocular biological parameters, changes in the eye might affect the incidence of eye diseases such as glaucoma and fundus diseases, which in turn might lead to changes in the spectrum of eye diseases.

Evaluation of the perception of information from ChatGPT in myopia education: Perspectives of students and professionals

PURPOSE

The purpose of this study was to compare the perception and understanding of the information provided by ChatGPT regarding myopia among optometry students, optometrists undertaking a Master degree and practicing optometrists.

METHODS

This was a cross-sectional descriptive study using a structured questionnaire distributed via Wooclap to 225 participants (125 optometry students, 21 Masters student and 79 practicing optometrists). All participants evaluated the responses generated by ChatGPT Version 4.0 using a five-point scale: very poor, poor, acceptable, good and very good. Data were analysed using SPSS, applying descriptive analysis and chi-squared tests to assess the significance of differences observed between the groups.

RESULTS

Practicing optometrists, with an average age of 39.7 ± 11.0 and 15.2 ± 7.5 years of professional experience, rated the information provided by ChatGPT on myopia complications more positively than the optometry and Masters student, highlighting the importance of clinical experience (p < 0.001). Alternatively, this may indicate a difference in awareness, knowledge and training, with younger students potentially being more speculative in their evaluations. The perceptions about myopia prevention among the groups were similar (p = 0.28). At the same time, the perceptions of the effectiveness of treatments such as contact lenses and pharmaceutical agents showed differences, with optometrists rating these treatments more positively (p < 0.001 and p = 0.004, respectively).

CONCLUSIONS

This study showed differences in the perception and interpretation of the information provided by ChatGPT about myopia depending on the level of education. While AI plays an important role in education, practicing optometrists trust the information extracted by ChatGPT more than optometry students.

Oblique effects with multisegment spectacle lenses: 1. Images of a point object

INTRODUCTION

Multisegment (MS) spectacles are intended to slow myopia progression by modifying images falling on the peripheral retina. Some published optical treatments of these lenses assume normal incidence of light at the surfaces, but images falling on the peripheral retina are usually associated with oblique ray pencils. Here, we model representative images of point objects produced by the Hoya MiyoSmart MS spectacle lens when oblique ray pencils are used.

METHODS

Various imaging aspects of the MS lens alone and in combination with a suitable accommodating eye model for a 4D myope were evaluated using the Optical Design program Ansys Zemax OpticStudio. Configurations studied included object points at vergences of zero and -4 D, with the objects being either on the lens axis or at a field angle of about 30°. The effect on foveal vision of rotating the axis of the eye with respect to that of the lens was also considered. Images of point objects were described in terms of spot diagrams and fast Fourier transform point-spread functions.

RESULTS

Symmetry and overall optical quality of images decreased with the obliquity of the ray pencils, due to the increased off-axis aberrations of the lens and the eye. Images of near object points were strongly affected by the level of accommodation: optimal retinal image quality occurred when accommodation brought the carrier lens focus close to the retina, rather than that of the lenslets.

CONCLUSIONS

Attempts to understand why MS lenses slow myopia progression need to consider the way in which through-focus retinal image quality changes with obliquity of the ray pencils across the visual field and the possible effects of ocular accommodation.

Association between Plasma Metabolite Levels and Myopia: A 2-Sample Mendelian Randomization Study

Purpose

The role of plasma metabolites in myopia is still unclear, and previous studies are limited by various factors and were mostly observational. This study aims to investigate the causal relationship between plasma metabolites and myopia using 2-sample Mendelian randomization (MR).

Design

A 2-sample MR study.

Subjects and Participants

This study analyzed plasma metabolites consisting of 1091 metabolites and 309 metabolite ratios in 8299 individuals from the Canadian Longitudinal Study on Aging cohort. Summary statistics for myopia were obtained from the UK Biobank, encompassing 37 362 cases and 460 536 controls.

Methods

Causal effect estimates were primarily derived using the inverse variance weighting (IVW) method and the constrained maximum likelihood and model averaging-based MR method. Statistical significance for the MR effect estimate was defined as a false discovery rate (FDR) of <0.05. Additionally, we used the MR Steiger directionality test to examine whether exposure was directionally causal for the outcome. Furthermore, 4 supplementary methods were used for analysis: weighted median, MR-Egger, simple mode, and weighted mode.

Main Outcome Measures

Genetic causal association between plasma metabolites and myopia.

Results

The IVW analysis results indicated that elevated levels of 1-arachidonoyl-GPE (20:4n6) (P_FDR = 5.80E-06), linoleoyl-arachidonoyl glycerol (18:2/20:4)[1] (P_FDR = 2.24E-06), and linoleoyl-arachidonoyl-glycerol (18:2/20:4) [2](P_FDR = 0.0242) have a protective effect on myopia. Elevated levels of 4 plasma metabolite ratios, including the phosphate to linoleoyl-arachidonoyl-glycerol (18:2/20:4) [2] ratio (P_FDR = 0.0029), citrulline to dimethylarginine (SDMA + ADMA) ratio (P_FDR = 0.0207), oleoyl-linoleoyl-glycerol (18:1/18:2) [2] to linoleoyl-arachidonoyl-glycerol (18:2/20:4) [1] ratio (P_FDR = 0.0230), and retinol (vitamin A) to linoleoyl-arachidonoyl-glycerol (18:2/20:4) [2] ratio (P_FDR = 0.0230), were significantly associated with a higher risk of myopia.

Conclusions

This study provides evidence of a causal relationship between specific plasma metabolites and myopia, highlighting potential therapeutic targets and contributing to the understanding of myopia's etiology. Future research should include diverse populations to enhance the generalizability of these findings.

Financial Disclosures

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

2024 Chew Sek Jin Memorial Lecture: "Are we there yet?"

The journey from myopia being an intriguing scientific puzzle to part of clinical practice has been a long and varied path. Chew Sek Jin was one of the pioneers on this journey and, as director of the Singapore Eye Research Institute, initiated an ambitious research program that has helped us get to where we are today. His work was data-driven, embracing the power of epidemiological and longitudinal studies. He emphasized both the public health aspects and clinical management of myopia, pioneering the use of atropine in Singapore. With his work with Josh Wallman, he recognized the importance of research into the biological mechanisms of myopia.

Visual performance of single-vision contact lenses utilizing opaque, nonrefractive features for potential myopia management

SIGNIFICANCE

Contact lenses (CLs) utilizing opaque, nonrefractive features may purposefully modulate retinal ganglion cell activity away from the baseline activity. This is a nonrefractive mechanism that may reduce myopia progression. However, the visual performance of CLs with opaque features is unknown.

PURPOSE

This study aimed to compare the visual performance and binocular/accommodative function of CLs with opaque features (test) against MiSight (control-1) and single-vision (control-2) CLs.

METHODS

This was a prospective, randomized, unmasked, cross-over study where 35 myopic CL wearers (18 to 39 years) wore each design for at least 5 days. Visual performance was subjectively assessed using 1 to 10 numeric ratings comprising clarity of vision, lack of ghosting, vision when driving, overall vision satisfaction, and willingness to purchase (yes/no: based on vision and myopia efficacy). Visual acuity measurements comprised monocular and binocular high and low contrast visual acuity at 6 m, and binocular high contrast visual acuity at 70 and 40 cm. Binocular function was assessed using heterophorias at 3 m and 40 cm. Accommodative function was assessed using monocular accommodative facility (MAF) at 40 cm and dynamic monocular accommodative response (AR: 6 m, 70 cm, and 40 cm).

RESULTS

Test was rated higher than control-1 (p<0.001) and control-2 was rated higher than test (p≤0.0052) for all subjective ratings. More participants were willing to purchase test compared with control-1 for vision and myopia efficacy (p<0.001), while there was no difference between test and control-2 for either question (p>0.7). Both controls were better than test for all acuity-based measurements (p≤0.0013). MAF at 40 cm was better with test compared with control-1 (p=0.010) and not different to control-2 (p>0.99). AR was higher with test than both controls at 70 cm (p<0.0001), higher than control-1 at 40 cm (p<0.0001), and not different to control-2 at 40 cm (p=0.12). There were no differences between CLs for AR at 6 m or heterophorias at 3 m or 40 cm (p>0.1).

CONCLUSIONS

Compared with control-1, the test offered better visual performance, a higher proportion of participants willing to purchase, and better MAF. Compared with control-2, the test offered worse visual performance, but the proportion of participants willing to purchase was not different, and accommodative function was comparable.

The causal effect of multiple lifestyles and myopia: a Mendelian randomization study

Previous studies have demonstrated that lifestyle was associated with myopia. This study used Mendelian randomization (MR) analysis to examine the causal relationships between the time of computer use, the time outdoors in summer and the time outdoors in winter and myopia. Subsequently, univariate MR (UVMR) analyses were carried out respectively on the three exposure factors and myopia, and the results were mainly based on the inverse-variance-weighted method. In addition, sensitivity analyses were also conducted, including heterogeneity tests, horizontal pleiotropy and leave-one-out methods, to evaluate the stability of the MR results. Multivariate MR (MVMR) analysis was also carried out. The UVMR analysis showed that two of the exposure factors had causal relationships with myopia: the time of computer use was a risk factor, and the time spent outdoors in summer was a protective factor. However, the time spent outdoors in winter had no direct impact on myopia. Furthermore, further mediation analysis showed that the frequency of solarium/sunlamp use was a mediating factor between the time outdoors in winter-myopia, and the mediating effect accounted for 36.93%. In conclusion, when multiple factors occurred simultaneously, the time of computer use in summer and the time of outdoor activities had a potential impact on myopia, and the time outdoors in winter affected myopia through the frequency of solarium/sunlamp use.

Do myopia control spectacle lenses with defocus incorporated multiple segments technology alter visual parameters and cortical activity?

PURPOSE

This study evaluated visual parameters and cortical activity after wearing myopia control spectacle lenses with defocus incorporated multiple segments (DIMS).

METHODS

Myopic adults between 20 and 30 years of age were enrolled. The study consisted of (1) examination of visual parameters and (2) measurement of cortical responses, while wearing single vision lenses (SVL) and MiYOSMART (MS) lenses in counterbalanced order after a two-week adaptation period. Visual parameters tested were: high-contrast visual acuity (HCVA) and low-contrast visual acuity (LCVA), contrast sensitivity, heterophoria, near point of convergence (NPC), stereopsis, accommodative facility and the accommodative response. Cortical responses were assessed by visual evoked potentials (VEPs), recorded from 10 electrodes placed over the parieto-occipital area.

RESULTS

MiYOSMART lenses produced slightly better HCVA than SVL (-0.25 vs. -0.21 logMAR, p = 0.02) and a larger accommodative response (MS 1.68 D; SVL 1.53 D, p < 0.001). No significant differences in LCVA, heterophoria, NPC, stereopsis or contrast sensitivity were observed. The latencies and amplitudes of the early and late components of the VEPs (C1, N1, P1, P2) did not differ significantly between lenses.

CONCLUSIONS

This study found no clinically significant differences in visual parameters or visual cortex responses between SVL and MS lenses after 2 weeks of adaptation. These results confirm the absence of adverse visual effects from DIMS lenses for myopia control.

Artificial intelligence in the diagnosis and management of refractive errors

Refractive error is among the leading causes of visual impairment globally. The diagnosis and management of refractive error has traditionally relied on comprehensive eye examinations by eye care professionals, but access to these specialized services has remained limited in many areas of the world. Given this, artificial intelligence (AI) has shown immense potential in transforming the diagnosis and management of refractive error. We review AI applications across various aspects of refractive error care - from axial length prediction using fundus images to risk stratification for myopia progression. AI algorithms can be trained to analyze clinical data to detect refractive error as well as predict associated risks of myopia progression. For treatments such as implantable collamer and orthokeratology lenses, AI models facilitate vault size prediction and optimal lens fitting with high accuracy. Furthermore, AI has demonstrated promise in optimizing surgical planning and outcomes for refractive procedures. Emerging digital technologies such as telehealth, smartphone applications, and virtual reality integrated with AI present novel avenues for refractive error screening. We discuss key challenges, including limited validation datasets, lack of data standardization, image quality issues, population heterogeneity, practical deployment, and ethical considerations regarding patient privacy that need to be addressed before widespread clinical implementation.

Optical influence of myopia control spectacles at the retinal level: Effect of local light modulation

PURPOSE

To investigate the influence of light modulation conferred by current designs of myopia control spectacles on retinal sensitivity.

METHODS

Retinal sensitivity and scanning laser ophthalmoscopy (SLO) fundus images were obtained from nine healthy subjects using a Macular Integrity Assessment microperimeter with current myopia control spectacle lenses: MyoCare, Stellest, MiYOSMART and DOT. Respectively powered single vision lenses and a 0.8-grade Bangerter occlusion foil (BF) served as comparative controls.

RESULTS

Using the SLO image, one can visualise the areas of light modulation of the various myopia control lens designs at the level of the retina. Clear zone sizes differ between lens designs, with the DOT lens having the smallest area. Retinal sensitivity in areas of local light modulation was not reduced for the Stellest and MyoCare lenses, but declined with the MiYOSMART lens, suggesting a more prominent local light modulation. The DOT lenses produced a significant reduction in overall retinal sensitivity, although the reduction with the BF was greater. In all instances, retinal sensitivity remained well above the range considered normal for a healthy retina.

CONCLUSIONS

None of the lenses tested produced a clinically relevant reduction in retinal sensitivity and all scored significantly better than the lowest (that is, 0.8) grade BF. Given that current myopia control spectacles do not show consistent treatment effects as required to slow progression effectively over extended periods, there appears to be a subtle, yet crucial difference in spatial light modulation among these myopia control spectacle lenses. Seemingly similar lens designs cannot be assumed to have equivalent treatment effects; a thorough assessment of these nuances is essential to ensure accurate claims regarding their long-term efficacy.

Digital therapeutics approach for young children with myopia using SAT-001 (DAYS): study protocol for a randomized controlled trial

BACKGROUND

Myopia is a prevailing refractive disorder and rapidly increases the risk of vision-threatening conditions. Earlier intervention is crucial to suppress myopia progression; however, the pharmacological and non-pharmacological therapies currently available have limitations. SAT-001 is a novel digital therapeutic software developed for myopia control and is designed to overcome the limitations of existing therapies. The present study aims to evaluate the efficacy and safety of the software as a medical device, SAT-001, for the inhibition of myopia progression and treatment in pediatric patients with myopia.

METHODS

This clinical trial is a two-arm, prospective, randomized, open-label study with a duration of approximately 25 months, comprising a maximum of 52 weeks of participant participation. We will enroll 110 pediatric patients with myopia aged 5 to < 9 years, each with a spherical equivalent of - 0.75 D to - 5.75 D in each eye. Eligible participants will be randomly assigned in a 1:1 ratio to either the study group using SAT-001 with single-vision spectacles or the control group using single-vision spectacles alone. The change in the spherical equivalent refractive error (SER) at 48 weeks from baseline serves as the primary endpoint. The change in SER at 24 weeks and axial length at every 12 weeks from baseline will be the secondary endpoints. Each change will be assessed depending on the myopic severity. Treatment emergent adverse events will be evaluated for the safety analysis.

DISCUSSION

This randomized controlled trial aims to confirm the efficacy and safety of SAT-001 in slowing pediatric myopia progression. The findings of this study could establish SAT-001 as an easily accessible, convenient, and non-invasive treatment option with minimal side effects, offering long-term myopia control from an early stage. Further research is needed to validate the effectiveness of SAT-001 for moderate to high myopia and concurrent conditions like astigmatism and to improve user engagement, diversify the program, and integrate with hospital-based treatments.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT06344572 ; date of registration: April 12, 2024 (retrospectively registered).

Association of physical activity, sedentary behaviour, sleep and myopia in children and adolescents: a systematic review and dose-response meta-analysis

PURPOSE

This study aimed to systematically evaluate the dose-response relationships between physical activity (PA), sedentary behavior(SB) (including near work [NW] and screen time [ST]), sleep duration (SD), and myopia risk among children and adolescents.

DESIGN

Systematic review and dose-response meta-analysis.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Library, and Web of Science up to November 19, 2024. Methodological quality was assessed using Joanna Briggs Institute (JBI) and ROBINS-I tools. Random-effects meta-analyses were used to estimate categorical and continuous dose-response relationships. Subgroup analyses and sensitivity analyses were performed to explore heterogeneity sources and test robustness.

RESULTS

A total of 45 observational studies (766,848 participants aged 5-19 years) were included. Categorical analyses showed that, compared with the lowest exposure categories, higher PA levels (highest: OR = 0.77, 95% CI: 0.63-0.96; intermediate: OR = 0.76, 95% CI: 0.63-0.93) and longer SD (highest: OR = 0.67, 95% CI: 0.48-0.92; intermediate: OR = 0.82, 95% CI: 0.73-0.92) significantly reduced myopia risk. Conversely, higher levels of NW (highest: OR = 1.71, 95% CI: 1.28-2.27; intermediate: OR = 1.34, 95% CI: 1.19-1.50) and ST (highest: OR = 1.59, 95% CI: 1.14-2.22; intermediate: OR = 1.29, 95% CI: 1.12-1.49) were associated with significantly increased risk. In the continuous dose-response meta-analysis, a linear association was observed between PA, ST, and myopia. Each additional hour of PA per day reduced the risk of myopia by 12%, while each additional hour of ST increased the risk by 31%. Nonlinear associations were found between NW, SD, and myopia. Among children and adolescents, 1.5 and 2.5 h/day of NW increased the risk of myopia by 25% and 29%, respectively. Although longer SD was associated with a reduced risk of myopia, this effect did not reach statistical significance at any exposure level.Subgroup analyses revealed that protective effects of PA were more evident in low- and middle-income countries, smaller sample sizes, and cross-sectional studies, while increased risks related to ST and NW were stronger in low-income settings. No subgroup significantly modified the association between SD and myopia risk.

CONCLUSION

Increasing PA, while limiting ST and NW, effectively reduces the risk of myopia among children and adolescents. The association between sleep duration and myopia remains inconclusive, warranting further investigation.

Absolute Risks and Decision Tools for Communicating the Risks of Visual Impairment From Myopia-Related Diseases

Purpose

The risks of developing myopia complications are frequently reported in relative terms, which can be misleading. This study provides absolute risk estimates of visual impairment (VI) from myopia-related diseases.

Methods

A critical integrative review provided data on frequency of myopic macular degeneration (MMD), primary open-angle glaucoma (POAG), rhegmatogenous retinal detachment (RRD), and associated VI in predominantly White and East Asian populations. The absolute risks of persons over 40 years of age with no myopia, low myopia (-2.00 D), or high myopia (-6.00 D) developing VI from each myopia-related disease were calculated by multiplying the proportion of each refractive group with the disease by the rate of VI. The sum of the risks of VI from MMD, POAG, and RRD provided an estimate of VI risk from any of these three myopia-related diseases in adults over 40 years old.

Results

VI from MMD, POAG, or RRD combined is expected in 0.4 in 100, 1.4 in 100, and 6.8 in 100 of White persons with no myopia, low myopia, or high myopia, respectively. The same risks in an East Asian population are 0.5 in 100, 2.4 in 100 and 10.3 in 100 in persons with no myopia, low myopia, or high myopia, respectively.

Conclusions

Absolute risks are provided to enable balanced discussions of the future risk that a child may have in developing VI from myopia-related diseases when considering myopia management. These estimates should be put into context using decision tools and balanced statements providing information on the likelihood of both developing VI and not developing VI.

Topical review: Potential mechanisms of atropine for myopia control

SIGNIFICANCE

Atropine is effective at slowing myopia progression in children, but the mechanism of action by which it controls myopia remains unclear. This article is an evidenced-based review of potential receptor-based mechanisms by which atropine may act to slow the progression of myopia.The rising number of individuals with myopia worldwide and the association between myopia and vision-threatening ocular pathologies have made myopia control treatments one of the fastest growing areas of ophthalmic research. High-concentration atropine (1%) is the most effective treatment for slowing myopia progression to date; low concentrations of atropine (≤0.05%) appear partially effective and are currently being used to slow myopia progression in children. While significant progress has been made in the past few decades in understanding fundamental mechanisms by which atropine may control myopia, the precise characterization of how atropine works for myopia control remains incomplete. It is plausible that atropine slows myopia via its affinity to muscarinic receptors and influence on accommodation, but animal studies suggest that this is likely not the case. Other studies have shown that, in addition to muscarinic receptors, atropine can also bind, or affect the action of, dopamine, alpha-2-adrenergic, gamma-aminobutyric acid, and cytokine receptors in slowing myopia progression. This review summarizes atropine's effects on different receptor pathways of ocular tissues and discusses how these effects may or may not contribute to slowing myopia progression. Given the relatively broad array of receptor-based mechanisms implicated in atropine control of myopia, a single mode of action of atropine is unlikely; rather atropine may be exerting its myopia control effects directly or indirectly via several mechanisms at multiple levels of ocular tissues, all of which likely trigger the response in the same direction to inhibit eye growth and myopia progression.

Reference ranges of light-adapted full-field electroretinogram and associated factors in a large cohort of healthy school-aged children and adolescents

PURPOSE

This study aimed to establish a reference data set of light-adapted full-field electroretinograms (ffERG) of healthy primary and secondary schoolchildren and investigate the relationship among refraction, ocular biometry, and ffERG.

METHODS

Healthy children aged between 6 and 17 years were recruited. Cycloplegic spherical equivalent refraction (SER), axial length (AL) and keratometry (K) measurements were performed. Standardized ffERGs, including light-adapted flash and 30-Hz flicker, were measured using a portable device with skin electrodes. The percentiles of peak time and amplitude of a- and b-waves and 30-Hz flicker of ffERG waveform were reported, and their relationships with age, SER, AL, K were investigated.

RESULTS

Among the 445 participants (45.4% female), the SER (mean ± standard deviation) was - 0.72 ± 2.06 D and AL was 23.56 ± 1.15 mm. The 90% confidence interval (CI) of 5th reference limit of amplitudes of a- and b-wave were 5.0-5.8 µV and 15.0-17.6 µV, while 95th reference limit of peak times were 13.2-13.4 ms and 29.8-30.0 ms, respectively. The amplitude and peak time of the 30-Hz flicker waveform were 21.5-23.9 µV and 26.0-26.2 ms, respectively. In general, more myopic SER, and longer AL were associated with delayed and reduced ffERG waveforms. Older age and male sex were weakly correlated with ffERGs with minimal clinical significance.

CONCLUSIONS

A reference data set of light-adapted ffERG in children and adolescents was established for clinical and research purposes.

Higher order aberrations according to spherical, and astigmatic refractive errors in children

CLINICAL RELEVANCE

The results of this study present novel insights into the impact of spherical and astigmatic refractive errors on overall, corneal and internal aberrations and may provide a clear understanding of the emmetropisation process and the development of visual function.

BACKGROUND

This study aimed to assess the association between overall, corneal and internal higher-order aberrations and the spherical and astigmatic components (magnitude and angle) of refractive error in a large sample of children.

METHODS

A total of 311 children aged 7 - 8 years old were classified based on spherical equivalent refraction (myopic, emmetropic and hyperopic); magnitude of astigmatism (none, low and moderate); and angle of astigmatism (with-the-rule, against-the-rule and oblique). Refractive error and overall, corneal and internal higher-order aberrations were measured using the OPD-Scan III workstation.

RESULTS

Regarding spherical equivalent refraction, myopic eyes had greater root mean square (RMS) overall higher-order values, total spherical, tetrafoil and secondary astigmatism aberrations, and internal higher-order, total spherical and tetrafoil aberrations in comparison to emmetropic eyes. The magnitude of astigmatism was positively associated with all overall RMS aberrations and with internal higher order, coma, total coma, total spherical and tetrafoil aberrations. Eyes with with-the-rule astigmatism showed higher RMS values of coma and total coma compared to eyes with against-the-rule and oblique astigmatism.

CONCLUSIONS

Higher-order aberrations are dependent on the spherical as well as astigmatic components of refractive error. These findings enhance the current understanding of the emmetropisation process and visual function development.

Longitudinal measures of peripheral optical quality in young children

PURPOSE

To assess longitudinal changes in optical quality across the periphery (horizontal meridian, 60°) in young children who are at high (HR) or low risk (LR) of developing myopia, as well as a small subgroup of children who developed myopia over a 3-year time frame.

METHODS

Aberrations were measured every 6 months in 92 children with functional emmetropia at baseline. Children were classified into HR or LR based on baseline refractive error and parental myopia. Zernike polynomials were calculated for 4 mm pupils, accounting for the elliptical shape of the pupil in the periphery. Various metrics were computed, including Strehl Ratios with only high-order aberrations (HO-SR). Primary spherical aberration (SA), horizontal coma and defocus were also analysed given their relevance in emmetropisation. The areas under the image quality metrics for various regions of interest were computed.

RESULTS

HO-SR were higher in children at HR and children with myopia, even when SA was removed from the Strehl Ratio (SR) calculation. SA was less positive in children at HR and children with myopia. Defocus was more negative in children at HR and children with myopia at all eccentricities and was even more negative when computed relative to the fovea, an effect that increased in the mid periphery. Relative peripheral defocus also became more negative over time in children at HR and children with myopia at the mid temporal retina. The other aberrations showed no significant changes in time overall.

CONCLUSIONS

This longitudinal study showed differences in HO-SR, SA and defocus in the central and near-peripheral retina (±20°) of young children at HR before they develop myopia compared with children at LR for myopia. The results may indicate these eccentricities are significant in providing signals for emmetropisation. The small changes noted over time may indicate that the differences are a cause of myopia development.

Efficacy of Myopia Prevention in At-Risk Children: A Systematic Review and Network Meta-Analysis

Objectives: To evaluate the efficacy of myopia prevention methods in children without pre-existing myopia. Methods: A network meta-analysis was conducted following the PRISMA-NMA guidelines. Comprehensive searches were performed in PubMed, Embase, and Cochrane CENTRAL databases. The analysis focused on randomized controlled trials evaluating myopia prevention strategies in children without prior myopia. Primary outcomes included annual changes in refraction and axial length, while secondary outcomes encompassed myopia incidence and adverse events. Effect sizes were reported as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CIs). Data synthesis utilized a random-effects model under a frequentist framework, with intervention efficacy ranked by P-scores. Study quality was assessed using the Cochrane risk-of-bias tool, and robustness was ensured via sensitivity and consistency analyses. Results: Low-level red light therapy and low-dose atropine were the most effective interventions for reducing refractive progression (MD: 0.48 D, 95% CI: 0.38-0.59 D; MD: 0.33 D, 95% CI: 0.23-0.43 D) and axial elongation (MD: -0.23 mm, 95% CI: -0.27 to -0.19 mm; MD: -0.12 mm, 95% CI: -0.16 to -0.08 mm). In addition, both significantly lowered myopia incidence (RR: 0.59, 95% CI: 0.45-0.79; RR: 0.55, 95% CI: 0.41-0.75). Outdoor activities and myopia awareness programs demonstrated moderate efficacy. Adverse events, including photophobia and dry eyes, were minor and self-limiting, with no serious complications reported. Conclusions: Low-level red light therapy and low-dose atropine are the most effective, generally safe strategies for preventing myopia in at-risk children without myopia, while a non-invasive approach, outdoor activities, provides moderate benefits.

Correlation of contrast sensitivity at low spatial frequencies with myopic shift in Chinese children

PURPOSE

To investigate the correlation of contrast sensitivity function (CSF) with myopic shift in Chinese children.

METHODS

This prospective case-series study included 62 eyes (31 children) who visited the Eye and ENT Hospital of Fudan University in January 2022 and were followed up for 6 months. Routine ophthalmic examinations and quantitative CSF (qCSF) tests without refractive correction were performed. Differences in CSF parameters, including the area under the log CSF (AULCSF), CSF acuity, and contrast sensitivity (CS) at 1.0-18.0 cpd, were compared between two groups stratified according to the myopic shift based on mydriatic spherical equivalent (<-0.50 D or ≥-0.50 D) during follow-up.

RESULTS

The myopia progressed by 0.13 ± 0.24 and 1.18 ± 0.75 D in the stabilized (28 eyes) and advanced (34 eyes) groups, respectively. Compared with the advanced group, the stabilized group showed significantly lower baseline qCSF test results for CSF acuity and CS at 1.0 and 1.5 cpd. The qCSF readings for CSF acuity and CS at 1.0, 1.5, and 3.0 cpd increased significantly during the 6-month follow-up in the stabilized group, while these values showed non-significant decreases in the advanced group. CS at 3.0 cpd was significantly correlated with myopic shift. Compared with the advanced group, participants in the stabilized group with higher myopia showed relatively significantly lower CS (baseline CSF acuity and CS at 1.0, 1.5, and 3.0 cpd).

CONCLUSIONS

Children with relatively slower myopic shift showed lower contrast sensitivity at low spatial frequencies, which might be an effective factor in myopia control.

Chinese parents' knowledge, attitude, and practice of myopia control: 2023 update

BACKGROUND

Our previous survey identified a lack of knowledge of myopia among Chinese parents. This research aims to update the characteristics of parents' knowledge, attitude, and practice in myopia control.

METHODS

A self-administered questionnaire was disseminated to parents of myopic children in 16 hospitals from 11 provinces in China. Comprehensive information regarding the knowledge, attitude, and practice in myopia of parents with myopic children was collected, with the underlying correlations being analyzed.

RESULTS

A total of 1266 valid questionnaires were collected. The concern over children's visual problems arose significantly earlier among myopic parents (P < 0.001). Axial length was recorded by 29.9% (378/1266) of the participants. Parents' primary goal of myopia control was "retarding the progression of myopia" (64.8%, 821/1266). The effectiveness of behavioral intervention was ranked first by 68.4% (866/1266) of the participants. Single-vision spectacles were the most adopted correction practice (26.1%, 331/1266). In terms of myopic interventions, 23.5% (297/1266) of the parents chose myopic control spectacles, followed by orthokeratology (20.9%, 264/1266); 37.3% (189/507) of the participants believed that the latter was more effective. Most parents (69.8%, 883/1266) expressed satisfaction with the current efficacy of myopia control.

CONCLUSION

Insufficient awareness of myopia and myopia control was identified among parents of myopic children in China. Efforts should be made to enhance parents' knowledge, raise their awareness, and improve the accessibility and affordability of effective myopia control interventions.

Myopia in Houston optometry graduates from 2013 to 2023

SIGNIFICANCE

Adult onset and progression of myopia are not well understood. It is of interest to better characterize myopia progression in young adults, who are frequently subjected to risk factors, such as intense near-work demands.

PURPOSE

This study aimed to assess the prevalence and progression of myopia and other refractive errors in optometry students in the United States.

METHODS

This study was a retrospective chart review of electronic medical records of students enrolled in the optometry program at the University of Houston College of Optometry who graduated between 2013 and 2023. For each student, refractive error was noted from the medical record for eye examinations during their time as an optometry student. Exclusion criteria were ocular disease, myopia control treatment, or refractive surgery. Prevalences of hyperopia (≥+ 0.50 D), emmetropia (>-0.50 to <+0.50 D), myopia (≤-0.50 D), astigmatism (>0.50 D), and anisometropia (≥1.0 D) were determined from spherical equivalent refraction (SER) of the right eye. Absolute and annualized differences in SER were calculated between visits.

RESULTS

Records for 1071 students were reviewed, and 961 were included. Prevalences were 80.7% for myopia, 14.9% for emmetropia, and 4.4% for hyperopia. Additionally, 38.4% had astigmatism, and 16.1% had anisometropia. Students with one follow-up exam (n = 639) showed a significant negative change in SER of -0.05 ± 0.38 D over an average follow-up period of 1.60 ± 0.61 years (p=0.001). Myopia onset was observed in 15.7% of emmetropes at baseline. Greater negative SER change was associated with greater follow-up duration and younger age. Hyperopes and emmetropes did not demonstrate significant changes in SER. An annualized negative SER change of ≥-0.25 D was noted in 20% of the 639 students, of which 5.5% showed ≥-0.50 D.

CONCLUSIONS

Findings demonstrate a high prevalence of myopia among optometry students. A small but statistically significant myopic change in refraction was observed. These findings may implicate a role of education and near work in myopia.

Exploring Molecular Pathways in Refractive Errors Associated with Inherited Retinal Dystrophies

The term inherited retinal dystrophies (IRDs) refers to a diverse range of conditions characterized by retinal dysfunction, and mostly deterioration, leading to a gradual decay of the visual function and eventually to total vision loss. IRDs have a global impact on about 1 in every 3000 to 4000 individuals. However, the prevalence statistics might differ significantly depending on the exact type of dystrophy and the demographic being examined. The cellular pathophysiology and genetic foundation of IRDs have been extensively studied, however, knowledge regarding associated refractive errors remain limited. This review aims to clarify the cellular and molecular processes that underlie refractive errors in IRDs. We did a thorough search of the current literature (Pubmed, accession Feb 2024), selecting works describing phenotypic differences among genes-related to IRDs, particularly in relation to refractive errors. First, we summarize the wide range of IRDs and their genetic causes, describing the genes and biological pathways connected to the etiology of the disease. We then explore the complex relationship between refractive errors and retinal dysfunction, including how the impairment of the vision-related mechanisms in the retina can affect ocular biometry and optical characteristics. New data about the involvement of aberrant signaling pathways, photoreceptor degeneration, and dysfunctional retinal pigment epithelium (RPE) in the development of refractive errors in IRDs have been examined. We also discuss the therapeutic implications of refractive defects in individuals with IRD, including possible approaches to treating visual impairments. In addition, we address the value of using cutting-edge imaging methods and animal models to examine refractive errors linked to IRDs and suggest future lines of inquiry for identifying new targets for treatment. In summary, this study presents an integrated understanding of the cellular and molecular mechanisms underlying refractive errors in IRDs. It illuminates the intricacies of ocular phenotypes in these conditions and offers a tool for understanding mechanisms underlying isolated refractive errors, besides the IRD-related forms.

Interventions for myopia control in children: a living systematic review and network meta-analysis

RATIONALE

The increasing prevalence of myopia is a growing global public health problem, in terms of rates of uncorrected refractive error and significantly, an increased risk of visual impairment due to myopia-related ocular morbidity. Interventions to slow its progression are needed in childhood, when myopia progression is most rapid. This is a review update, conducted as part of a living systematic review.

OBJECTIVES

To assess the comparative efficacy and safety of interventions for slowing myopia progression in children using network meta-analysis (NMA). To generate a relative ranking of interventions according to their efficacy. To produce a brief economic commentary, summarising economic evaluations.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and three trial registers. The latest search date was 19 February 2024.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) of optical, pharmacological, light therapy and behavioural interventions for slowing myopia progression in children, up to 18 years old.

OUTCOMES

Critical outcomes were progression of myopia (mean difference (MD) in the change in spherical equivalent refraction (SER, dioptres (D)), and axial length (AL, mm) in the intervention and control groups at one year or longer), and difference in the change in SER and AL following cessation of treatment (rebound).

RISK OF BIAS

We assessed the risk of bias (RoB) for SER and AL using the Cochrane RoB 2 tool.

SYNTHESIS METHODS

We followed standard Cochrane methods. We rated the certainty of evidence using the GRADE approach for change in SER and AL at one and two years. We used the surface under the cumulative ranking curve (SUCRA) to rank the interventions for all available outcomes.

INCLUDED STUDIES

We included 104 studies (40 new for this update) that randomised 17,509 children, aged 4 years to 18 years. Most studies were conducted in China or other Asian countries (66.3%), and North America (14.4%). Eighty-four studies (80.8%) compared myopia control interventions against inactive controls. Study durations ranged from 12 months to 48 months.

SYNTHESIS OF RESULTS

Since most of the networks in the NMA were poorly connected, our estimates are based on direct (pairwise) comparisons, unless stated otherwise. The median change in SER for controls was -0.65 D (55 studies, 4888 participants; one-year follow-up). These interventions may reduce SER progression compared to controls: repeated low intensity red light (RLRL: MD 0.80 D, 95% confidence interval (CI) 0.71 to 0.89; SUCRA = 93.8%; very low-certainty evidence); high-dose atropine (HDA (≥ 0.5%): MD 0.90 D, 95% CI 0.62 to 1.18; SUCRA = 93.3%; moderate-certainty evidence); medium-dose atropine (MDA (0.1% to < 0.5%): MD 0.55 D, 95% CI 0.17 to 0.93; NMA estimate SUCRA = 75.5%; low-certainty evidence); low dose atropine (LDA (< 0.1%): MD 0.25 D, 95% CI 0.16 to 0.35; SUCRA = 53.2%; very low-certainty evidence); peripheral plus spectacle lenses (PPSL: MD 0.45 D, 95% CI 0.16 to 0.74; SUCRA = 50.2%; very low-certainty evidence); multifocal soft contact lenses (MFSCL: MD 0.27 D, 95% CI 0.18 to 0.35; SUCRA = 49.9%; very low-certainty evidence); and multifocal spectacle lenses (MFSL: MD 0.14 D, 95% CI 0.08 to 0.21; SUCRA = 30.8%; low-certainty evidence). The median change in AL for controls was 0.33 mm (58 studies, 9085 participants; one-year follow-up). These interventions may reduce axial elongation compared to controls: RLRL (MD -0.33 mm, 95% CI -0.37 to -0.29; SUCRA = 98.6%; very low-certainty evidence); HDA (MD -0.33 mm, 95% CI -0.35 to -0.30; SUCRA = 88.4%; moderate-certainty evidence); MDA (MD -0.24 mm, 95% CI -0.34 to -0.15; NMA estimate SUCRA = 75.8%; low-certainty evidence); LDA (MD -0.10 mm, 95% CI -0.13 to -0.07; SUCRA = 36.1%; very low-certainty evidence); orthokeratology (ortho-K: MD -0.18 mm, 95% CI -0.21 to -0.14; SUCRA = 79%; moderate-certainty evidence); PPSL (MD -0.13 mm, 95% CI -0.21 to -0.05; SUCRA = 52.6%; very low-certainty evidence); MFSCL (MD -0.11 mm, 95% CI -0.13 to -0.09; SUCRA = 45.6%; low-certainty evidence); and MFSL (MD -0.06 mm, 95% CI -0.09 to -0.04; SUCRA = 26.3%; low-certainty evidence). Ortho-K plus LDA probably reduces axial elongation more than ortho-K monotherapy (MD -0.12 mm, 95% CI -0.15 to -0.09; SUCRA = 81.8%; moderate-certainty evidence). At two-year follow-up, change in SER was reported in 34 studies (3556 participants). The median change in SER for controls was -1.01 D. The ranking of interventions to reduce SER progression was close to that observed at one year; there were insufficient data to draw conclusions on cumulative effects. The highest-ranking interventions were: HAD (SUCRA = 97%); MDA (NMA estimate SUCRA = 69.8%); and PPSL (SUCRA = 69.1%). At two-year follow-up, change in AL was reported in 33 studies (3334 participants). The median change in AL for controls was 0.56 mm. The ranking of interventions to reduce axial elongation was similar to that observed at one year; there were insufficient data to draw conclusions on cumulative effects. The highest-ranking interventions were: ortho-K plus LDA (SUCRA = 94.2%); HAD (SUCRA = 96.8%); and MDA (NMA estimate SUCRA = 88.4%). There was limited evidence on whether cessation of myopia control therapy increases progression beyond the expected rate of progression with age. Adverse events and treatment adherence were not consistently reported. Two studies reported quality of life, showing little to no difference between intervention and control groups. We were unable to draw firm conclusions regarding the relative costs or efficiency of different myopia control strategies in children.

AUTHORS' CONCLUSIONS

Most studies compared pharmacological and optical treatments to slow the progression of myopia with an inactive comparator. These interventions may slow refractive change and reduce axial elongation, although results were often heterogeneous. Less evidence is available for two years and beyond; uncertainty remains about the sustained effect of these interventions. Longer term and better quality studies comparing myopia control interventions alone or in combination are needed, with improved methods for monitoring and reporting adverse effects.

FUNDING

Cochrane Eyes and Vision US Project is supported by grant UG1EY020522, National Eye Institute, National Institutes of Health.

REGISTRATION

The previous version of this living systematic review is available at doi: 10.1002/14651858.CD014758.pub2.

Efficacy and Safety of Different Atropine Regimens for the Treatment of Myopia in Children: Three-Year Results of the MOSAIC Randomized Clinical Trial

Importance

Additional data are required regarding atropine treatment regimens for control of myopia progression.

Objective

To investigate the efficacy and safety of different atropine regimens for myopia in children.

Design, Setting, and Participants

This was a secondary analysis of the 3-year results of the 24-Month Myopia Outcome Study of Atropine in Children (MOSAIC) trial, called the MOSAIC2 trial. The MOSAIC trial was an investigator-led, double-masked, randomized clinical trial of different atropine concentrations and regimens. The MOSAIC2 study took place at the Centre for Eye Research Ireland, in Dublin, Ireland, and included children and adolescents with myopia from the MOSAIC trial. Data analysis was conducted from November 2023 to February 2024.

Interventions

Participants were randomly assigned to the following cohorts: group 1, nightly placebo for 2 years then 0.05% atropine eye drops for 1 year and group 2, nightly 0.01% atropine eye drops for 2 years then rerandomization to placebo nightly, tapering placebo, or tapering of 0.01% atropine eye drops for 1 year.

Main Outcomes and Measures

Observed changes in cycloplegic spherical equivalent refraction and axial length from month 24, or baseline, to month 36.

Results

A total of 199 children with myopia (mean [SD] age, 13.9 [2.4] years; 121 female [60.8%]) of the 250 children and adolescents from the MOSAIC trial were included in the MOSAIC2 trial analysis. Of 83 participants assigned to group 1, 66 (79.5%) reconsented to year 3, and 61 (73.5%) completed the trial. Of 167 participants assigned to group 2, 133 (79.6%) continued to year 3, and 121 (72.5%) completed the trial (0.01% atropine, then nightly placebo: n = 31 and n = 29 [93.5%]; 0.01% atropine, then tapering placebo: n = 29 and n = 25 [86.2%]; 0.01% atropine then tapering 0.01% atropine: n = 73 and n = 67 [91.8%], respectively). Compared with the group taking placebo then 0.05% atropine, the combined atropine then placebo groups had more spherical equivalent progression (adjusted difference, -0.13 diopters [D]; 95% CI, -0.22 to -0.04 D; P = .01) and axial elongation (adjusted difference, 0.06 mm; 95% CI, 0.02-0.09 mm; P = .008), and the group taking 0.01% atropine then tapering 0.01% atropine had more axial elongation (adjusted difference, 0.04 mm; 95% CI, 0.009-0.07 mm; P = .04). In the group taking placebo then 0.05% atropine, 15% (n = 10) and 8% (n = 5) reported blurred near vision and photophobia, respectively, during year 3, compared with 3% (n = 2) and 0%, respectively, in the group taking 0.01% atropine then tapering 0.01% atropine, and no reports in both placebo groups.

Conclusions and Relevance

Despite more adverse events, participants using 0.05% atropine during year 3 had no differences in treatment completion rates and exhibited 0.13-D less myopia progression and 0.06-mm less axial elongation, compared with participants using placebo, supporting consideration of treatment as given to the group taking 0.05% atropine in this European population.

Trial Registration

isrctn.org Identifier: ISRCTN36732601.

Subjective impressions with myopia control contact lenses versus single vision lenses: A systematic review and meta-analysis

PURPOSE

To gain insight into patients' visual experiences and satisfaction when using different forms of myopia control lenses.

METHODS

PubMed, Cochrane Library, Embase, Scopus and Web of Science databases were searched for articles assessing subjective visual quality with myopia control lenses compared with single-vision lenses (SVLs) up to July 10, 2023. Eight-hundred-and-three articles were retrieved, reviewed and any questionnaire items on subjective impressions of lens wear were meta-analysed. Subgroup analyses were based on the magnitude of defocus (add power) of multifocal soft contact lenses (MFSCLs) and age groups. A random-effects model was employed for meta-analysis, and I2 statistic used to assess the statistical heterogeneity.

RESULTS

Nineteen articles fit the criteria, but only six articles involving MFSCLs had relevant data. MFSCLs were associated with lower subjective ratings of vision at different distances compared to SVLs (p < 0.001), but the differences were less than one unit. MFSCLs also yielded lower ratings when moving or walking and/or climbing stairs at -0.38 (-0.69 to -0.07, p = 0.02; I2 = 85 %, p < 0.001) and for subjective comfort (difference of -0.23, -0.41 to -0.05, p = 0.01; I2 = 63 %, p < 0.001). Subjective ratings for playing sports were not different between groups. Experience with MFSCLs was rated lower by young adults compared to children for all variables. In both children and young adults, ratings were lower with higher add compared to lower add MFSCLs.

CONCLUSION

Although subjective ratings for vision and comfort were lower with MFSCLs compared to SVLs, the difference was mostly less than one unit. Importantly, young adults rated their visual experience lower compared to children.

Dynamic changes of choroidal vasculature and its association with myopia control efficacy in children during 1-year orthokeratology treatment

PURPOSE

To investigate the dynamic changes of choroidal vasculature and its association in mediating ocular elongation over 1 year of orthokeratology (ortho-k) treatment.

METHODS

This observational study included 8-14 year old myopic children who were willing to receive ortho-k treatment or wear single vision spectacle lenses (SVL). Axial length (AL) and choroidal characteristics, including submacular luminal area (LA), stromal area (SA), total choroidal area (TCA), choroidal vascularity index (CVI), subfoveal choroidal thickness (SFCT) and choriocapillaris flow deficits (CcFD) from OCT/OCTA images, were evaluated at baseline, 3, 6 and 12 months.

RESULTS

After 1 year, AL elongation was significantly less in 25 children treated with ortho-k than in 29 children wearing SVL (0.17 ± 0.14 v.s. 0.28 ± 0.16 mm, P<0.01). In the ortho-k group, LA, SA, TCA and SFCT were significantly increased by 0.033 ± 0.059 mm2, 0.024 ± 0.035 mm2, 0.058 ± 0.087 mm2, 8.9 ± 17.4 μm, respectively, at 3 months (all P<0.05). These parameters returned to near baseline levels over the following 9 months. Meanwhile, CcFD decreased by 0.83 ± 1.09 % over 12 months, but CVI remained steady during this period. No significant changes in these choroidal parameters (except for CcFD, decreased by -0.56 ± 1.23 %) were observed in the SVL group over 12 months. Increases in SFCT, LA, SA and TCA over 12 months were significantly greater in the ortho-k group than in the SVL group. Mediation analyses showed that 44.8 % of effect on inhibiting AL elongation through ortho-k was mediated via TCA (in particular LA).

CONCLUSIONS

The decelerated ocular elongation during ortho-k treatment is accompanied by increases in content of choroidal vascular lumen and stromal component. Dynamic changes of choroidal vasculature provide a possible mechanism underlying myopia control efficacy via ortho-k.

Can fundus features tell us something about 3D eye shape?

PURPOSE

To determine whether imaging features derived from fundus photographs contain 3D eye shape information beyond that available from spherical equivalent refraction (SER).

METHODS

We analysed 99 eyes of 68 normal adults in the UK Biobank. An ellipsoid was fitted to the entire volume of each posterior eye (vitreous chamber without the lens)-segmented from magnetic resonance imaging of the brain. Asphericity was computed based on the semidiameters of the ellipsoid's axes to describe posterior eye shape along the horizontal (temporal-nasal) and vertical (superior-inferior) meridians, while volume was calculated as the total number of foreground voxels. Mixed-effects linear regression models were used to test the association of SER with asphericity and volume, controlling for age and sex. Then, the association between various fundus features and asphericity was tested-both before and after controlling for SER, age and sex.

RESULTS

Posterior eyes were generally oblate (asphericity > 0), but the degree of oblateness reduced as SER decreased, with the shape tending towards prolateness in high myopia. Neither sex nor age influenced asphericity. However, males had larger posterior eyes on average (this difference disappeared after height was additionally controlled for). Optic disc (OD) orientation, OD-fovea angle, vessel tortuosity, vessel fractal dimension and central retinal arteriolar or venular equivalent (CRAE or CRVE) showed significant univariable associations with asphericity along at least one meridian. After controlling for SER, age and sex, a more negative OD-fovea angle (larger OD-fovea angular separation) remained significantly associated with reduced horizontal oblateness (p = 0.01). Similarly, decreasing CRAE (narrower arterioles) remained significantly associated with reduced oblateness along both the horizontal (p = 0.04) and vertical (p < 0.01) meridians.

CONCLUSIONS

Variations in OD-fovea angle and CRAE are associated with differences in ocular asphericity-even in eyes with similar SER-suggesting that fundus imaging provides eye shape information beyond what is available from refractive error alone.

Measuring the visual environment of children and young people at risk of myopia: a scoping review

PURPOSE

Myopia (short-sightedness) is an emerging WHO priority eye disease. Rise in prevalence and severity are driven by changes in lifestyle and environment of children and young people (CYP), including less time spent in bright daylight and more time spent on near-vision activities. We aimed to systematically map the literature describing direct, objective measurements of the visual environment of CYP.

METHODS

We conducted searches in Ovid Medline 1946, Ovid Embase and The Cochrane Central Register of Controlled Trials in November 2024. We included primary research written in English on environmental/behavioural factors and myopia onset/progression in CYP 3-18 years. Two reviewers independently screened titles/abstracts/full texts.

RESULTS

We included 34 articles: 21 explored the association of indoor and/or outdoor light exposure and myopia and included light measurements, two near-vision activities, four both light and near-work, four time outdoors without illuminance measurements, and three light exposure based on meteorological data. Most measurements were carried out at the level of individual children, rather than the surrounding environment alone.

CONCLUSION

Despite limitations in measurement techniques, there is evidence that reduced illuminance, less time spent in bright light and increased daily duration/sustained episodes of near-vision activities and reduced working distance are associated with increased myopia prevalence/progression.

Infectious keratitis following photorefractive keratectomy: a 13-year study at a tertiary center

INTRODUCTION

Infectious keratitis is a rare but devastating complication following photorefractive keratectomy (PRK) that may lead to visual impairment. This study assessed the clinical features, treatment strategies, and outcomes of post-PRK infectious keratitis.

METHODS

This retrospective study was conducted on patients with post-PRK infectious keratitis presenting to Khalili Hospital, Shiraz, Iran, from June 2011 to March 2024. The study was conducted in two stages: the first stage assessed the incidence of post-PRK infectious keratitis among patients who underwent PRK at our center, while the second stage included all patients with post-PRK infectious keratitis, regardless of where their PRK was performed. The following data were collected: demographics, post-surgery presentation time, risk factors, culture results, treatments, follow-up duration, complications, and corrected distance visual acuity (CDVA) at admission and the last follow-up.

RESULTS

Forty-two patients (42 eyes) with a mean age of 28.74 years (male-to-female ratio of 1.2:1) were included. Among 38,938 PRK procedures performed at our center, the incidence of keratitis was estimated to be 0.018% (7/38,938). The odds of keratitis during the COVID-19 pandemic were 7.05 times higher (95% CI: 1.58 to 31.52, p-value = 0.015) than outside this timeframe (February 2020 to August 2023). Gram-positive bacteria were the most commonly isolated pathogens in microbiological studies, accounting for 45.2% (19/42) of cases. Early-onset infections were primarily caused by Staphylococcus aureus (9/26, 34.6%), Staphylococcus epidermidis (4/26, 15.4%), and Pseudomonas aeruginosa (4/26, 15.4%), whereas all of the cases with fungi (4/4, 100% (and Acanthamoeba (3/3, 100%) infections caused late-onset infections. All patients received broad-spectrum antibiotic therapy, followed by adjusted treatment based on microbial results. Cases developing endophthalmitis and those not responding to treatment or having non-resolving corneal scars required further interventions, such as penetrating keratoplasty and deep vitrectomy. The mean follow-up duration was 40.81 months, and 97.6% (41/42) of cases experienced CDVA improvement at follow-up.

CONCLUSION

This long-term study found a post-PRK keratitis rate of 0.018%, with gram-positive bacteria as the most common pathogens. Prompt management and regular follow-up assessments are essential for achieving satisfactory outcomes.

Ocular Biometry OCR: a machine learning algorithm leveraging optical character recognition to extract intra ocular lens biometry measurements

Given close relationships between ocular structure and ophthalmic disease, ocular biometry measurements (including axial length, lens thickness, anterior chamber depth, and keratometry values) may be leveraged as features in the prediction of eye diseases. However, ocular biometry measurements are often stored as PDFs rather than as structured data in electronic health records. Thus, time-consuming and laborious manual data entry is required for using biometry data as a disease predictor. Herein, we used two separate models, PaddleOCR and Gemini, to extract eye specific biometric measurements from 2,965 Lenstar, 104 IOL Master 500, and 3,616 IOL Master 700 optical biometry reports. For each patient eye, our text extraction pipeline, referred to as Ocular Biometry OCR, involves 1) cropping the report to the biometric data, 2) extracting the text via the optical character recognition model, 3) post-processing the metrics and values into key value pairs, 4) correcting erroneous angles within the pairs, 5) computing the number of errors or missing values, and 6) selecting the window specific results with fewest errors or missing values. To ensure the models' predictions could be put into a machine learning-ready format, artifacts were removed from categorical text data through manual modification where necessary. Performance was evaluated by scoring PaddleOCR and Gemini results. In the absence of ground truth, higher scoring indicated greater inter-model reliability, assuming an equal value between models indicated an accurate result. The detection scores, measuring the number of valid values (i.e., not missing or erroneous), were Lenstar: 0.990, IOLM 500: 1.000, and IOLM 700: 0.998. The similarity scores, measuring the number of equal values, were Lenstar: 0.995, IOLM 500: 0.999, and IOLM 700: 0.999. The agreement scores, combining detection and similarity scores, were Lenstar: 0.985, IOLM 500: 0.999, and IOLM 700: 0.998. IOLM 500 was annotated for ground truths; in this case, higher scoring indicated greater model-to-annotator accuracy. PaddleOCR-to-Annotator achieved scores of detection: 1.000, similarity: 0.999, and agreement: 0.999. Gemini-to-Annotator achieved scores of detection: 1.000, similarity: 1.000, and agreement: 1.000. Scores range from 0 to 1. While PaddleOCR and Gemini demonstrated high agreement, PaddleOCR offered slightly better performance upon reviewing quantitative and qualitative results.

Broadband Long Wavelength Light Promotes Myopic Eye Growth and Alters Retinal Responses to Light Offset in Chick

Purpose

Prolonged exposure to broadband light with a short-wavelength (blue) or long-wavelength (orange/red) bias is known to impact eye growth and refraction, but the mechanisms underlying this response are unknown. Thus, the present study investigated the effects of broadband blue and orange lights with well-differentiated spectrums on refractive development and global flash electroretinography (gfERG) measures of retinal function in the chick myopia model.

Methods

Chicks were raised for 4 days with monocular negative lenses, or no lens, under blue, orange, or white light. Chick weight, eye dimensions, and refraction were measured at the conclusion of rearing. In a separate cohort of chicks, the effect of 4 days of colored light rearing on retinal responses to orange, blue, or white light flashes was assessed using gfERG.

Results

Chicks reared under orange light for 4 days exhibited a significantly larger myopic shift in response to negative lenses compared to those reared under blue light. Orange light rearing for 4 days increased the gfERG d-wave amplitude and implicit time in response to orange light flashes but did not alter responses to white or blue flashes. Blue and white light rearing did not affect the retina's response to light flashes of any color.

Conclusions

Orange light rearing exacerbated defocus-induced myopia relative to blue light rearing. The gfERG recordings revealed that prolonged orange light exposure increased retinal responsivity to the offset of long wavelength light flashes, suggesting a potential role for ON/OFF pathway balance in generating the refractive response that requires further electrophysiological and molecular investigation.

Cross-population validation of the PreMO risk indicator for predicting myopia onset in children

PURPOSE

The Predicting Myopia Onset and progression (PreMO) risk indicator, developed using data generated from white children in the UK, incorporates age, spherical equivalent refraction (SER), axial length (AL) and parental myopia to stratify the likelihood of developing myopia. This study evaluated the PreMO's predictive accuracy using prospective datasets from independent samples of children in Hong Kong (HK) and an ethnically diverse cohort of children in the United Kingdom.

METHODS

Non-myopic children (SER > -0.50 D) aged 6-8 and 9-10 years were scored using the PreMO risk indicator framework, integrating baseline cycloplegic SER, AL and parental myopia data. Scores were assigned risk categories as follows: 0 = no risk, 1-3 = low risk, 4-6 = moderate risk and 7-9 = high risk. SER at ≥15 years of age was used to define refractive outcomes as 'myopic' or 'not myopic'. PreMO's predictive accuracy was analysed via Receiver Operator Characteristic curves, with Youden's J-Index identifying the optimal risk score threshold. Sensitivity, specificity and area under the curve were determined and compared with those of singular predictors, that is, SER < +0.75 D and AL ≥ 23.07 mm at 6-8 years.

RESULTS

In the cohort of children aged 6-8 years, a PreMO risk score ≥ 4 exhibited high sensitivity in predicting myopia onset in UK (0.97) and HK (0.94) children, with high specificity in UK (0.96) and moderate specificity in HK (0.64) children. In UK children aged 6-8 years, the PreMO outperformed singular predictors such as SER and AL. Among HK children aged 9-10 years, the PreMO score maintained high sensitivity (0.90) and moderate specificity (0.72).

CONCLUSIONS

A PreMO risk score ≥ 4 is a strong predictive indicator for future myopia onset, particularly in UK children. Despite high sensitivity in both UK and HK cohorts, specificity varied, indicating the need for contextual application of the tool, particularly in pre-myopic Asian children.

Choroidal thickness in macular, nasal midperiphery, and temporal midperiphery regions and its relationship with axial length and refractive error

PURPOSE

This study aimed to investigate the choroidal thickness (ChT) distribution in adult myopic eyes, focusing on the macular, nasal midperiphery, and temporal midperiphery regions, and to explore its relationship with axial length (AL) and refractive error.

STUDY DESIGN

A cross-sectional, observational study.

METHODS

Twenty-nine eyes of 29 adult volunteers were examined. ChT was measured using high-speed swept-source optical coherence tomography covering an area of 50 degrees in three different regions: centered at macular, nasal side at 33 degrees, and temporal side at 33 degrees. Statistical analyses were performed to assess differences in ChT between regions and correlations with AL and spherical equivalent (SE).

RESULTS

ChT was found to be thickest in the macular region, followed by the nasal and temporal midperiphery regions. Significant correlations were observed between AL/SE and ChT in the macular and temporal regions, but not in the nasal region. The temporal midperiphery showed the strongest correlation with AL and SE.

CONCLUSION

This study revealed a nasal-temporal asymmetry in ChT distribution in myopic eyes, with the temporal midperiphery showing the thinnest ChT. The strong correlations between ChT in the temporal midperiphery and AL/SE suggest a role for the temporal choroid in axial elongation and myopia progression. These findings highlight the importance of considering peripheral ChT in understanding ocular growth and myopia management.

Incidence of microbial keratitis associated with overnight orthokeratology: a multicenter collaborative study

PURPOSE

To investigate the incidence of microbial keratitis among Japanese patients wearing orthokeratology (ortho-k) lenses STUDY DESIGN: Retrospective multicenter study METHOD: This study was conducted at 4 hospitals in Japan and involved 1438 patients who had been prescribed ortho-k lenses and had worn them for at least 3 months. Data on patient demographics, lens characteristics, lens care systems, and presence of microbial keratitis were extracted from the medical records. Duration of ortho-k lens wear was calculated from the original fitting date to the patient's last visit, with the total years of lens wear used as person-years of lens wear. The incidence of microbial keratitis was calculated by dividing the number of infected cases by the total person-years of lens wear for all enrolled participants.

RESULTS

Among the 1438 patients, 753 were male and 685 were female, with a mean age of 12.7 ± 5.4 years. The mean duration of ortho-k lens wear was 5.2 ± 4.5 years, and the mean lens power was -3.52 ± 1.41 D. The total person-years of lens wear for all enrolled patients was 7415. Four cases of microbial keratitis were identified, resulting in an overall incidence of microbial keratitis of 5.4 (95% CI: 1.0-9.8) per 10,000 patient-years among ortho-k lens wearers.

CONCLUSION

This study represents the largest sample size to date for estimating the incidence of microbial keratitis associated with ortho-k lenses. The incidence was similar to or slightly lower than that of previous studies on ortho-k-related microbial keratitis and also comparable to that of daily wear soft contact lenses.

The Optical Nature of Myopic Changes in Retinal Vessel Caliber

Purpose

Dimensional measures of retinal features are subject to the optical influence of ocular magnification. We examined the impact of ocular magnification on the association between axial length (AL) and measurements of retinal vessel caliber in fundus photographs.

Design

Cross-sectional study.

Participants

Eighty-two normal right eyes from healthy participants aged 16 to 31 years.

Methods

Central retinal arteriolar and venular equivalents (CRAE and CRVE) were derived from color fundus photographs using semiautomated software. Ordinary least squares linear regression was used to assess the influence of AL (independent variable) on CRAE and CRVE, controlling for age, sex, and ethnicity, both before and after magnification correction using different formulae. These formulae estimate magnification based on different ocular parameters: AL only (Bennnett's formula), refractive error only (Bengtsson's formula), and refractive error combined with keratometry (Littmann's formula). Previous research has primarily relied on Bengtsson's formula, which is less accurate than Bennett's formula. We also examined the impact of treating the nontelecentric fundus camera used in this study as telecentric when applying these magnification correction formulae.

Main Outcome Measures

Central retinal arteriolar and venular equivalents (in pixels).

Results

Before magnification correction, increasing AL was associated with decreasing CRAE (β: -0.49, 95% confidence intervals: -0.89 to -0.09, P = 0.02) and CRVE (β: -0.91, 95% confidence intervals: -1.62 to -0.20, P = 0.01). After magnification correction, this observation was no longer evident, regardless of the correction formula applied. When inappropriately assuming the fundus camera to be telecentric, we observed a bias toward increasing magnification-corrected CRAE and CRVE with increasing AL (β coefficients were positive or became more positive), reaching statistical significance (P < 0.05) for CRAE corrected using Bennett's or Littmann's formula, and for CRVE corrected using Bennett's formula.

Conclusions

Failing to correct for ocular magnification results in apparent narrowing of vessels in longer eyes, while inappropriate assumptions about telecentricity during magnification correction introduce an optical artifact that causes apparent widening of vessels. These findings suggest that myopic changes in retinal vessel caliber are optical (not biological) in nature. Proper correction of this effect to accurately derive dimensional measures is a crucial-yet often overlooked-methodological consideration in "oculomics" research investigating retinal biomarkers of systemic conditions.

Financial Disclosures

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

Shaping school for childhood myopia: the association between floor area ratio of school environment and myopia in China

AIM

To investigate the association of floor area ratio (FAR), an indicator of built environments, and myopia onset.

METHODS

This prospective cohort study recruited 136 753 children aged 6-10 years from 108 schools in Shenzhen, China at baseline (2016-2017). Refractive power was measured with non-cycloplegic autorefraction over a 2-year follow-up period. FAR was objectively evaluated using geographical information system technology. Mixed-effects logistic regression models were constructed to examine the association of FAR with a 2-year cumulative incidence of myopia among individuals without baseline myopia; multiple linear regression model, with a 2-year cumulative incidence rate of myopia at each school.

RESULTS

Of 101 624 non-myopic children (56.3% boys; mean (SE) age, 7.657±1.182 years) included in the study, 26 391 (26.0%) of them developed myopia after 2 years. In the individual-level analysis adjusting for demographic, socioeconomic and greenness factors, an IQR in FAR was associated with a decreased risk of 2-year myopia incidence (OR 0.898, 95% CI 0.866 to 0.932, p<0.001). Similar findings were observed in the analysis additionally adjusted for genetic and behavioural factors (OR 0.821, 95% CI 0.766 to 0.880, p<0.001). In the school-level, an IQR increase in FAR was found to be associated with a 2.0% reduction in the 2-year incidence rate of myopia (95% CI 1.3% to 2.6%, p<0.001).

CONCLUSIONS

Exposure to higher FAR was associated with a decreased myopia incidence, providing insights into myopia prevention through school built environments in China.

Experimental Myopia Results in Peripapillary Ganglion Cell and Astrocyte Reorganization with No Functional Implications During Early Development

Myopic eye growth induces mechanical stretch, which can lead to structural and functional retinal alterations. Here, we investigated the effect of lens-induced myopic growth on the distribution of retinal ganglion cells (RGCs), glial fibrillary acidic protein (GFAP) expression and intensity, and peripapillary retinal nerve fiber layer (ppRNFL) thickness in common marmosets (Callithrix jacchus) induced with myopia continuously for six months, using immunohistochemistry and spectral-domain optical coherence tomography. We also explored the relationship between cellular structural parameters and the photopic negative response (PhNR) using full-field electroretinography. Marmosets induced with myopia for six months developed axial myopia, had a thinner ppRNFL, reduced peripapillary ganglion cell (≈20%) and astrocyte density (≈42%), increased panretinal GFAP expression (≈42%) and nasal mid-periphery staining intensity (≈81%) compared to age-matched controls. Greater degrees of myopia and vitreous elongation were associated with reduced peripapillary RGCs and astrocyte density, and increased GFAP expression and intensity. These cellular structural changes did not show a significant relationship with the features of the PhNR, which remained unchanged. The outcomes of this study suggest that myopia induces a reorganization of the peripapillary inner retina at the cellular level that may not result in measurable functional repercussions at this stage of myopia development.

Myopia prevalence, refractive status and uncorrected myopia among primary and secondary school students in Germany

Introduction

The increasing prevalence of myopia worldwide is problematic because myopia can result in severe secondary pathologies, and is associated with considerable financial burden. With plenty of prevalence data available for some regions, current data for Europe remain sparse. Yet, information on myopia prevalence and associations is essential for monitoring, preventive and interventive purposes. Likewise, uncorrected refractive errors are also critical, as they can, e.g., affect educational outcomes, making information on uncorrected myopia valuable for diagnostics and health education.

Methods

We performed non-cycloplegic autorefraction on two samples in Germany. The younger sample included 489 primary school students (grades 3-4, mean age: 9.30 ± 0.78 years), the older sample 1,032 secondary school students (grades 8-10, mean age 14.99 ± 1.12 years). These samples mark the limits of the age range during which school myopia usually emerges.

Results

Myopia (spherical equivalent ≤ -0.75D) prevalence was 8.4% in the younger sample and 19.5% in the older sample. The prevalence was generally higher in higher grade levels, with the most notable difference between grades 8 and 9. Females were more myopic than males in all grades except grade 3, with the largest gender difference in grade 10. The older sample also exhibited a more myopic spherical equivalent than the younger sample. In the older sample, spherical equivalent was more myopic in females than in males, and in grade 9 and 10 participants more than in grade 8 participants. Rates of uncorrected myopia were extremely high: 51.2% in the younger sample and 43.3% in the older sample.

Discussion

The obtained myopia prevalence rates are generally consistent with other European studies, as is the higher prevalence in female than male adolescents, accelerating with age. The high rates of uncorrected myopia warrant further investigation and should inform public health policies, including the implementation of regular refractive screenings.

Trends in myopia prevalence among late adolescents in South Korea: a population-level study and future projections up to 2050

OBJECTIVE

This study aims to provide updated prevalence estimates of myopia and high myopia among late adolescent men in Seoul, South Korea, and predict future trends up to 2050.

METHODS AND ANALYSIS

This cross-sectional and population-level study includes late adolescent men of the same age who underwent a series of medical examinations at the Seoul Regional Military Manpower Administration between 2013 and 2022. The population with myopia and high myopia was estimated, and the prevalence for 2050 was forecasted. Associated risk factors and ocular disease status of the high myopia population were investigated.

RESULTS

Over the 10-year period, the prevalence of myopia and high myopia among late adolescent men in Seoul was 70.67% and 20.29%, respectively. Between 2013 and 2022, the prevalence of the myopia and high myopia has increased significantly (p<0.001 and 0.006, respectively). The annual growth rate for the prevalence of myopia and high myopia was 0.61% and 0.33%, respectively. Regression analyses predicted that by 2050, myopia and high myopia prevalence will reach 90.90% and 31.26% by linear regression, and 90.75% and 31.17% by non-linear regression, respectively. Risk factor analysis identified that a high education level was associated with a higher prevalence of high myopia. Retinal detachment was significantly more common among those with high myopia, while retinal dystrophy was less common.

CONCLUSION

This study highlights a concerning trend of increasing myopia and high myopia prevalence, which is likely to reach 90.90% and 31.26% by 2050, with significant future burden for public health and society.

Evaluation of the peripheral visual performance of DIMS spectacle lenses versus single vision lenses

Purpose

This study evaluates differences in the visual field performance when wearing the Defocus Incorporated Multiple Segments (DIMS) spectacle lens compared to wearing a conventional single vision (SV) spectacle lens.

Methods

Twenty-one children aged 9-14 years with spherical equivalent refraction (SER) between -1.13D to -4.75D were recruited. Mid-peripheral near visual acuity (NVA) under room lighting condition (500 lux ±10%) was measured using DIMS and SV lenses, respectively. Automated static perimetry (Zeiss, Humphrey Visual Field HFA 750i) with SITA Fast 30-2 protocol was used to investigate the visual field sensitivity. During the test, the study lens (Plano DIMS or SV lens) were inserted into the lens holder in front of the trial lenses with each child's compensated prescription.

Results

Three children were not able to complete the reliable visual tests due to fixation losses (>20%) or high false positive rate (>15%) while 18 children successfully completed the test. The mean visual field sensitivity was 29.2 ± 3.7 decibels (dB) and 29.3 ± 3.5 dB when wearing DIMS and SV lens, respectively. The mean sensitivity differences between DIMS and SV lens among 76 locations ranged from -2.4 ± 3.9 dB to 1.6 ± 3.9 dB. No statistically significant difference in sensitivity was observed across 76 locations within the central 30o between DIMS and SV lens (Wilcoxon signed rank test with bonferroni correction for multiple comparisons, p > 0.00065). Compared to SV lens, 0.05 logarithm of minimal angle of resolution (logMAR) reduction in mid-peripheral NVA in all 4 quadrants (Superior, Temporal, Inferior and nasal, p < 0.05) was noted with the DIMS lens (N = 18). However, no statistically significant correlation was found between the mid-peripheral NVA and visual sensitivity at the specific locations.

Conclusion

Although the mid-peripheral NVA was slightly reduced using DIMS lens, wearing DIMS lens did not change the children's visual sensitivity to detect the static stimulus within 30o visual field when compared to wearing SV lens.

Cultural roots of the myopia boom in Confucian Asia and their implications

Current evidence implicates educational pressures and reduced outdoor time as major causes of myopia. This paper examines the ongoing battle against the myopia epidemic in East Asia, including its cultural offshoots such as Singapore, where over 80% of young adults are myopic. East Asian societies share deeply rooted Confucian values that attach great importance to education and familial obligations, with heavy parental investment in education and the perception that academic excellence reflects filial piety. Coupled with a strong emphasis on standardised test results, East Asian children face intense educational pressures from a young age. Existing education-based myopia prevention strategies focus either on top-down school reforms to promote more outdoor time for students during school hours or on bottom-up awareness initiatives encouraging lifestyle changes. However, the entrenched Confucian worldview suggests that more extensive top-down reforms aimed at reducing competition in education, combined with widespread bottom-up awareness initiatives targeting the public-particularly parents, given their active involvement in children's education outside of school-may be required to truly turn the tide on myopia.

Experimental Evaluation of Ocular Rigidity and Pressure-Volume Relationship After Ex-Vivo Scleral Cross-Linking With Riboflavin and Ultraviolet A in Porcine Eyes

PURPOSE

Scleral cross-linking (SXL) with ultraviolet A (UVA) and riboflavin has already been used in laboratory studies for scleral stiffness increase as a potential treatment for progressive myopia and scleral ectasia. This study aims to investigate whether the regional application of scleral cross-linking (SXL) with ultraviolet A (UVA) and riboflavin in fresh porcine eye globes affects the ocular rigidity as well as its impact on intraocular pressure after an induced acute increase in the volume of intraocular fluid.

METHODS

The study included two groups of fresh porcine eyes: an experimental group (n=20) that underwent scleral cross-linking (SXL) with riboflavin and UVA applied to the posterior sclera and a control group (n=20) that did not receive SXL treatment. Subsequently, a balanced salt solution (volumes 50, 100, 150, and 200 μL) was administered into porcine globes via a syringe, and, at the same time, the intraocular pressure (IOP) was continuously monitored by a pressure sensor that was cannulated to the vitreous chamber. The relationship between volume and pressure was obtained, and the ocular rigidity coefficient (K) was calculated according to Friedenwald's law. Finally, scleral strips were dissected from the globes and were examined macroscopically.

RESULTS

In the control group, the mean IOP observed entails gradual, statistically significant increases for higher volumes. Specifically, the mean IOP at 0 μL equals 10 mmHg (SD=0), whereas at 200 μL the mean IOP equals 33.83 mmHg (SD=4.060). The differences were statistically significant with p-values <0.001 in all cases. Similarly, the observed gradual IOP increases in the SXL group were statistically significant with p < 0.001 in all cases except for the comparison of volume 0 μL measurements to volume 50 μL, where the p-value equaled 0.003. Specifically in the SXL group, the mean IOP at 0 μL equals 10.00 mmHg (SD=0.000), the mean IOP at 50 μL equals 13.31 mmHg (SD=2.011), whereas the mean IOP at 200 μL equals 32.06 mmHg (SD=3.078). At no additional injected volume, the differences between the control and the SXL groups were statistically significant. The analysis regarding ocular rigidity indicated significantly higher scores in the control group (K50=0.00812, SD=0.03) compared to the SXL group (K50=0.00552, SD=0.027), t=2.844; p=0.007. The difference regards measures of volumes 0 to 50 μL, while all other rigidity measures were found to be non-significant. Interestingly, the ocular rigidity coefficient in the SXL-treated group did not show changes with an increase in IOP. The macroscopic appearance of the scleral strips showed a significantly increased stiffness of the SXL scleras against the control ones.

CONCLUSION

This study showed that stiffened scleras did not induce substantial change in ocular rigidity and significant IOP elevations. Studying the biomechanical ocular response of laboratory scleral crosslinking applications supports the development of next-generation crosslinking procedures that may constitute potential therapeutic options for severe ophthalmic diseases like pathologic myopia.

Dynamics of Myopia Progression in Ghana-Evidence From Clinical Practice: A Retrospective Cohort Study

Background and Aim

To investigate the pattern of progression of myopia among a Ghanaian clinical cohort.

Methods

A retrospective cohort analysis of a clinical data set of all healthy myopic participants attending a tertiary eye care center was performed. Participants' biennial refraction examinations were tracked for refractive changes 4 years after the date of the first visit. This covered the period from January 2015 to December 2019. Myopia progression was defined as a difference in spherical equivalent between consecutive biennial visits equal to, or greater than -0.50 D of myopia.

Results

The medical records of 169 myopic participants were reviewed, with the majority (53.8%) being female. Most of the participants (51.4%) were younger than 36 years, and at the end of the study period, 96 participants (56.8%), who made up the majority, showed progression of myopia Univariate regression revealed that the 36-59-year-old age range is associated with a 60% [cOR = 0.40, 95% CI: -0.17, 0.97; p = 0.04] reduced likelihood compared to those belonging to the 0-17-year-old age group, and the Mole-Dagbon ethnicity is associated with an almost fourfold [cOR = 3.80; 95% CI: -1.40, 10.316; p = 0.01] increased likelihood of experiencing myopia progression compared to those of Ga-Adangbe ethnicity. Multivariate regression revealed that the Mole-Dagbon ethnicity is associated with an increased likelihood of experiencing myopia progression 4 years after their initial visit [aOR = 3.49; 95% CI: -1.27, 9.63; p = 0.02] compared to those of Ga-Adangbe ethnicity.

Conclusion

Our study provides important insights into myopia progression in Ghana, with findings that are consistent with global trends. The association of myopia progression with age, place of residence, degree of myopia, and ethnicity highlights the need for tailored interventions to manage this growing public health concern in African populations.

Ocular biometric responses to simulated polychromatic defocus

Evidence from human studies of ocular accommodation and studies of animals reared in monochromatic conditions suggest that chromatic signals can guide ocular growth. We hypothesized that ocular biometric response in humans can be manipulated by simulating the chromatic contrast differences associated with imposition of optical defocus. The red, green, and blue (RGB) channels of an RGB movie of the natural world were individually incorporated with computational defocus to create two different movie stimuli. The magnitude of defocus incorporated in the red and blue layers was chosen such that, in one case, it simulated +3 D defocus, referred to as color-signed myopic (CSM) defocus, and in another case it simulated -3 D defocus, referred to as color-signed hyperopic (CSH) defocus. Seventeen subjects viewed the reference stimulus (unaltered movie) and at least one of the two color-signed defocus stimuli for ∼1 hour. Axial length (AL) and choroidal thickness (ChT) were measured immediately before and after each session. AL and subfoveal ChT showed no significant change under any of the three conditions. A significant increase in vitreous chamber depth (VCD) was observed following viewing of the CSH stimulus compared with the reference stimulus (0.034 ± 0.03 mm and 0 ± 0.02 mm, respectively; p = 0.018). A significant thinning of the crystalline lens was observed following viewing of the CSH stimulus relative to the CSM stimulus (-0.033 ± 0.03 mm and 0.001 ± 0.03 mm, respectively; p = 0.015). Differences in the effects of CSM and CSH conditions on VCD and lens thickness suggest a directional, modulatory influence of chromatic defocus. On the other hand, ChT responses showed large variability, rendering it an unreliable biomarker for chromatic defocus-driven responses, at least for the conditions of this study.

Axial length reduction and choroidal thickening with short-term exposure to cyan light in human subjects

PURPOSE

Given the potential role of light and its wavelength on ocular growth, this study investigated the effect of short-term exposure to red, cyan and blue light on ocular biometry in humans.

METHODS

Forty-four young adults and 20 children, comprising emmetropes and myopes, underwent 2-h sessions of cyan (507 nm), red (638 nm) and broadband white light on three separate days via light-emitting glasses. Additionally, young adults were exposed to blue light (454 nm) on an additional day. Axial length (AL) and choroidal thickness (CT) were measured in the right eye before the light exposure (0 min), after 60 and 120 min of exposure and 30 min after light offset using an optical biometer and optical coherence tomographer, respectively.

RESULTS

Compared to broadband light, exposure to red light resulted in a significant increase in AL (mean difference between white and red light at 120 min, +0.007 mm [0.002]), but no significant change in CT, while cyan light caused a significant AL reduction (-0.010 mm [0.003]) and choroidal thickening (+0.008 mm [0.002]) in young adults (p < 0.05). Blue light caused a significant decrease of -0.007 mm (0.002) in young adult eyes at 60 min (p < 0.05). In children, cyan light led to a significant reduction in AL (-0.016 mm [0.004]) and strong sustained choroidal thickening (+0.014 mm [0.004]) compared to broadband light at 120 min (p < 0.05). The effects of cyan light on AL and CT were found to be stronger in myopic young adults and emmetropic children. The opposing effects of red and cyan light on ocular biometry were similar between the two age groups (p > 0.05).

CONCLUSIONS

Exposure to cyan light resulted in AL reduction and choroidal thickening in both young adults and children. Further research is needed to determine the application of these results in developing interventions for myopia control.

Can we really distinguish 'responders' from 'non-responders' to myopia control interventions?

PURPOSE

It is common to hear talk of 'responders' and 'non-responders' with respect to myopia control interventions. We consider the reality of distinguishing these sub-groups using data from the first year of the Low-concentration Atropine for Myopia Progression (LAMP) study.

METHODS

The first year of the LAMP study was a robustly designed, placebo-controlled trial of three different low concentrations of atropine using a large sample size (N > 100 randomised to each group). The authors subsequently published mean axial elongation and myopia progression rates by age group. We used these data to calculate efficacy in terms of both absolute reduction in myopic progression and absolute reduction in axial elongation for each of the different atropine concentrations at each age group. We then compared these efficacy data to the overall progression for each of the two progression metrics.

RESULTS

Plotting efficacy as a function of overall myopia progression and axial elongation for each of the different atropine concentrations demonstrates the invariant nature of efficacy, in terms of clinically meaningful reduction in progression, despite a substantial range of underlying overall progression. That is, faster progressors-the so-called non-responders-achieved similar reduction in axial elongation and myopia progression as the slower progressors-the so-called responders-within the various atropine treatment groups.

CONCLUSION

The use of the terms, responders and non-responders, during myopia progression interventions is not supported by evidence. Those designated as such may simply be slower or faster progressors, who, on average achieve the same benefit from treatment.

Climate and Rhegmatogenous Retinal Detachment: A Comprehensive Review and Future Research Guidelines

Purpose

Does weather affect the rate of developing rhegmatogenous retinal detachment (RRD)? This comprehensive review investigates the findings of the most recent studies on the relationship between RRD and climatic or seasonal factors.

Methods

An extensive search across PubMed, Embase, and Google Scholar databases resulted in 112 initial results, from which 18 studies published between 1980 and 2024 were selected. The selection criteria were based on the studies' relevance to our topic. We analyzed their methodology, geographic scope, and key findings. Data extraction encompassed study design, sample size, sex ratio, incidence rates, results, and identified limitations.

Results

Eight studies found no statistically significant relationship between seasonal variations and the incidence of RRD. Conversely, seven studies reported an increased incidence of RRD during the summer months. Additionally, secondary analyses of factors, such as ambient temperature, atmospheric pressure, and daylight hours, showed varied and sometimes conflicting results. A summary of common limitations and biases was synthesized into a table, providing guidelines for future research exploring this topic.

Conclusion

This comprehensive review highlights the complex interaction between environmental factors and RRD incidence. The conflicting results across different studies suggest a need for further research in this area. Future studies should address the identified limitations and biases to provide a clearer understanding of the relationship between climate and RRD. By utilizing the guidelines from our review, future research could aim to minimize confounding factors and improve the robustness of their findings. Understanding these interactions can be used to develop preventive strategies and enhance clinical practices to reduce the burden of RRD.