Myopia

Exome-wide association study identifies KDELR3 mutations in extreme myopia

Extreme myopia (EM), defined as a spherical equivalent (SE) ≤ -10.00 diopters (D), is one of the leading causes of sight impairment. Known EM-associated variants only explain limited risk and are inadequate for clinical decision-making. To discover risk genes, we performed a whole-exome sequencing (WES) on 449 EM individuals and 9606 controls. We find a significant excess of rare protein-truncating variants (PTVs) in EM cases, enriched in the retrograde vesicle-mediated transport pathway. Employing single-cell RNA-sequencing (scRNA-seq) and a single-cell polygenic burden score (scPBS), we pinpointed PI16 + /SFRP4+ fibroblasts as the most relevant cell type. We observed that KDELR3 is highly expressed in scleral fibroblast and involved in scleral extracellular matrix (ECM) organization. The zebrafish model revealed that kdelr3 downregulation leads to elongated ocular axial length and increased lens diameter. Together, our study provides insight into the genetics of EM in humans and highlights KDELR3's role in EM pathogenesis.

Identification of Potential Drug Targets for Myopia Through Mendelian Randomization

Purpose

The purpose of this study was to identify potential drug targets for myopia and explore underlying mechanisms.

Methods

Mendelian randomization (MR) was implemented to assess the effect of 2684 pharmacologically targetable genes in the blood and retina on the risk of myopia from a genomewide association study (GWAS) for age-at-onset of spectacle wearing-inferred mean spherical equivalent (MSE; discovery cohort, N = 287,448, European), which was further validated in a GWAS for autorefraction-measured MSE (replication cohort, N = 95,619, European). The reliability of the identified significant potential targets was strengthened by colocalization analysis. Additionally, enrichment analysis, protein-protein interaction network, and molecular docking were performed to explore the functional roles and the druggability of these targets.

Results

This systematic drug target identification has unveiled 6 putative genetically causal targets for myopia-CD34, CD55, Wnt3, LCAT, BTN3A1, and TSSK6-each backed by colocalization evidence in adult blood eQTL datasets. Functional analysis found that dopaminergic neuron differentiation, cell adhesion, Wnt signaling pathway, and plasma lipoprotein-associated pathways may be involved in myopia pathogenesis. Finally, drug prediction and molecular docking corroborated the pharmacological value of these targets with LCAT demonstrating the strongest binding affinity.

Conclusions

Our study not only opens new avenues for the development of therapeutic interventions for myopia but may also help to understand the underlying mechanisms of myopia.

Effects of 2 Hz flickering light on refractive state, fundus imaging and visual function of C57BL/6 mice

In this study, we investigated the effects of flickering light on refractive development of mice and the changes of fundus structure and function during this process. C57BL/6 mice were randomly divided into control group and flickering light-induced myopia (FLM) group. Mice in the control group were fed under normal lighting. FLM group mice were fed under lighting with a duty cycle of 50% and flash frequency of 2 Hz. Refractive status, axial length (AL), corneal radius of curvature (CRC), and electroretinogram signals were measured in all animals before treatment and at 2 and 4 weeks after treatment. Retinal thickness (RT), choroidal thickness (ChT) and choroidal blood perfusion (ChBP) were measured by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). After 4 weeks of flickering light stimulation, the mice became myopia, the AL increased, but the CRC remained constant. The induction of myopia reduced the implicit time and amplitude of a-wave and b-wave in electroretinogram, which affects the function of retina. Full-layer retinal thickness, ChT and ChBP decreased at both 2 and 4 weeks after flickering light induction. The superficial and middle layers of the retina were significantly thinner, while the deep layer was only slightly thinner without statistical significance. Calculated by the concentric circle algorithm, the decrease of choroidal blood perfusion in FLM was mainly concentrated in the concentric circle area with the optic disc as the center radius of 150-450 μm. In conclusion, the present study shows that flickering light can successfully induce myopia in C57BL/6 mice, affect the electrophysiological activity of retina, and cause changes in fundus tissue structure and blood flow.

Knowledge, attitude, and practice of non-ophthalmic medical staff toward myopia-related fundus lesions

This study assessed the knowledge, attitude, and practice (KAP) of non-ophthalmic medical staff towards myopia-related fundus lesions. This multicenter, cross-sectional study enrolled non-ophthalmic medical staff of Suining City between January and May 2023 using a self-designed questionnaire. A total of 505 (93.19%) valid questionnaires were included. Their mean KAP scores were 8.10 ± 2.32 (range: 0-12), 20.27 ± 2.68 (range: 0-24), and 17.77 ± 5.04 (range: 0-28), respectively. Structural equation modeling indicated that knowledge has a positive effect on attitude (β = 0.307, P < 0.001), and attitude has a positive effect on practice (β = 0.604, P < 0.001). Moreover, a higher degree of myopia exhibited a positive effect on knowledge (β = 0.510, P < 0.001). Nurses and other medical staff showed a negative effect on knowledge (β = - 0.706, P < 0.001) compared to doctors. Working in secondary and tertiary public hospitals, as well as private hospitals, demonstrated a negative effect on practice (β = - 1.963, P < 0.001) compared to those working in primary hospitals. Non-ophthalmic medical staff exhibited moderate knowledge, positive attitudes, and moderate practices toward myopia-related fundus lesions. The degree of myopia, doctors vs. other medical staff, and the hospital level influence the KAP of non-ophthalmic medical staff.

Long-term effect of orthokeratology on choroidal thickness and choroidal contour in myopic children

PURPOSE

To investigate the long-term effect of orthokeratology (ortho-k) on the choroidal thickness and choroidal contour in myopic children.

METHODS

Subjects were from a conducted 2-year randomised clinical trial. Children (n=80) aged 8-12 years with spherical equivalent refraction of -1.00 to -6.00D were randomly assigned to the control group (n=40) and ortho-k group (n=40). Optical coherence tomography images were collected at the baseline, 1-month, 6-month, 12-month, 18-month and 24-month visits, then the choroidal thickness and choroid contour were calculated. Axial length (AL) and other ocular biometrics were also measured.

RESULTS

During 2 years, in the control group, the choroidal thickness became thinning and the choroidal contour became prolate with time at all visits (all p<0.001). Ortho-k can improve the choroidal thickness (all p<0.001) and maintain the choroidal contour at all visits (all p<0.05). In the ortho-k group, the choroidal contour was less changed in the temporal than nasal (p=0.008), and the choroidal thickness was more thickening in the temporal 3 mm (p<0.001). Two-year change in choroidal thickness was significantly associated with the 2-year AL change in the control group (r=-0.52, p<0.001), however, this trend was broken by ortho-k (r=-0.05, p=0.342). After being adjusted by other variables in the multivariable regression model, the effect of ortho-k on choroidal thickness was stable.

CONCLUSIONS

In the current 2-year prospective study, ortho-k can improve the choroidal thickness and maintain the choroidal contour, but this effect diminished in a long term. Further study with larger sample size and longer follow-up is warranted to refine this issue.

High correlated color temperature artificial lighting impairs retinal pigment epithelium integrity and chloride ion transport: A potential mechanism for choroidal thinning

Among the environmental factors contributing to myopia, the role of correlated color temperature (CCT) of ambient light emerges as a key element warranting in-depth investigation. The choroid, a highly vascularized and dynamic structure, often undergoes thinning during the progression of myopia, though the precise mechanism remains elusive. The retinal pigment epithelium (RPE), the outermost layer of the retina, plays a pivotal role in regulating the transport of ion and fluid between the subretinal space and the choroid. A hypothesis suggests that variations in choroidal thickness (ChT) may be modulated by transepithelial fluid movement across the RPE. Our experimental results demonstrate that high CCT illumination significantly compromised the integrity of tight junctions in the RPE and disrupted chloride ion transport. This functional impairment of the RPE may lead to a reduction in fluid transfer across the RPE, consequently resulting in choroidal thinning and potentially accelerating axial elongation. Our findings provide support for the crucial role of the RPE in regulating ChT. Furthermore, we emphasize the potential hazards posed by high CCT artificial illumination on the RPE, the choroid, and refractive development, underscoring the importance of developing eye-friendly artificial light sources to aid in the prevention and control of myopia.

Long-term effect of orthokeratology on controlling myopia progression in children with allergic conjunctivitis

BACKGROUND

To observe whether the effect of orthokeratology (OK) lenses on myopia control in children with allergic conjunctivitis (AC) after three years of wear differs from that in children without allergic conjunctivitis (nAC) and to identify the potential influencing factors.

METHODS

This was a retrospective case-control study. Patients aged 8-15 years who were fitted with OK lenses in 2019 were collected. A three-year follow-up was also conducted, documenting all corneal adverse events (AEs) and the increase in axial length (AL) of the eye after three years of wearing OK lenses. Patients were divided into groups with and without AC based on their medical history and physical signs at the initial fitting. Baseline data and AL elongation after three years were compared between the two groups.

RESULTS

A total of 309 patients were included in this study, with 47 in the AC group and 262 in the nAC group. There were no statistically significant differences between the two groups in terms of age, sex, spherical equivalent (SE), AL of the eye and environment. After three years of OK lens wear, the AL elongation in the AC group was 0.96 ± 0.45 mm, whereas it was 0.69 ± 0.45 mm in the nAC group (P < 0.001). The extent of AL elongation in AC patients was significantly greater than that in nAC patients. During the three-year follow-up period, the duration of OK lenses discontinuation due to corneal AEs in the AC group was greater than that in the nAC group (P < 0.05).

CONCLUSIONS

This study found that allergic conjunctivitis can affect the efficacy of OK lenses in controlling myopia after three years of treatment.

Palladium nanocrystals regulates scleral extracellular matrix remodeling in myopic progression by modulating the hypoxia signaling pathway Nrf-2/Ho-1

Myopia represents a widespread global public health concern influenced by a combination of environmental and genetic factors. The prevailing theory explaining myopia development revolves around scleral extracellular matrix (ECM) remodeling, characterized by diminished Type I collagen (Col-1) synthesis and increased degradation, resulting in scleral thinning and eye axis elongation. Existing studies underscore the pivotal role of scleral hypoxia in myopic scleral remodeling. This study investigates the peroxidase-like activity and catalytic performance of octahedral Palladium (Pd) nanocrystals, recognized as nanozymes with antioxidative properties. We explore their potential in reducing oxidative stress and alleviating hypoxia in human scleral fibroblasts (HSF) and examine the associated molecular mechanisms. Our results demonstrate the significant peroxidase-like activity of Pd nanocrystals. Furthermore, we observe a substantial reduction in oxidative stress in HSF under hypoxia, mitigating cellular damage. These effects are linked to alterations in Nrf-2/Ho-1 expression, a pathway associated with hypoxic stress. Importantly, our findings indicate that Pd nanocrystals contribute to attenuated scleral matrix remodeling in myopic guinea pigs, effectively slowing myopia progression. This supports the hypothesis that Pd nanocrystals regulate myopia development by controlling oxidative stress associated with hypoxia. Based on these results, we propose that Pd nanocrystals represent a novel and potential treatment avenue for myopia through the modulation of scleral matrix remodeling. This study introduces innovative ideas and directions for the treatment and prevention of myopia.

Parallel comparison of ocular metrics in non-human primates with high myopia by LS900, ultrasonography and MRI-based 3D reconstruction

We investigate the ocular dimensions and shape by using Lenstar900 (LS900), A-scan ultrasonography, and Magnetic Resonance Imaging (MRI) in highly myopic Macaca fascicularis. The ocular dimensions data of LS900, A-scan ultrasonography and MRI was assessed from 8 eyes (4 adult male cynomolgus macaque) with extremely high myopia (≤-1000DS) and compared by means of coefficients of concordance and 95% limits of agreement. Multiple regression analysis was performed to explore the associations between ocular biometry, volume, refraction and inter-instrument discrepancies. Test-retest reliability of three measurements of ocular parameters at two time points was almost equal (intraclass correlation = 0.831 to 1.000). The parallel-forms reliability of three measurements was strong for vitreous chamber depth (VCD) (coefficient of concordance = 0.919 to 0.981), moderate for axial length (AL) (coefficient of concordance = 0.486 to 0.981), and weak for anterior chamber depth (ACD) (coefficient of concordance = 0.267 to 0.621) and lens thickness (LT) (coefficient of concordance = 0.035 to 0.631). The LS900 and MRI systematically underestimated the ACD and LT comparing to A-scan ultrasonography (P < 0.05). Notably, the average AL on LS900 displayed a significant correlation with those on MRI (r = 0.978, P < 0.001) and A-scan ultrasonography (r = 0.990, P < 0.001). Almost 4/5 eyeballs were prolate. The mean eyeball volume positively correlated with AL (r = 0.782, P = 0.022), the width (r = 0.945, P = 0.000), and the length (r = 0.782, P = 0.022) of eyeball, while negatively correlated with SER (r = -0.901, P = 0.000). In conclusion, there was a high inter-instrument concordance for VCD with LS900, A-scan ultrasonography and MRI, while ACD and LT were underestimated with LS900 compared to A-scan ultrasonography, and the LS900 and A-scan ultrasonography could reliably measure the AL. MRI further revealed an equatorial globe shape in extremely myopic non-human primates.

Factors affecting choroidal circulation parameters in 4-14-year-old Chinese children measured by SS-OCT/OCTA

PURPOSE

To measure the choroidal circulatory parameters Han Chinese children aged 4-14 years from Southwest China, and to explore the relationships between these parameters and age, axial length (AL), and choroidal thickness (ChT).

METHODS

284 eyes from 142 subjects were included in this cross-sectional study. All participants underwent cycloplegic refraction and IOLMaster500 examination. Swept-source optical coherence tomography (SS-OCT) was used to measure submacular choroidal thickness, choroidal vascular volume (CVV), choroidal stromal volume (CSV), choroidal vascularity index (CVI), and CVV/CSV ratio.

RESULTS

In this population, the mean CVV was 2.92 ± 0.55 mm3, CSV was 4.69 ± 0.68 mm3, CVI was 38.22 ± 2.46 %, and CVV/CSV ratio was 62.11 ± 6.44 %. Multivariable regression analyses showed that both CVV and CSV were negatively correlated with AL (both P < 0.001) and positively correlated with ChT (both P < 0.001), while age showed no significant correlation with them (both P > 0.05). However, the correlations between CVI and age were not uniform rectilinear. Among participants aged ≤8 years, CVI showed no correlation with age (P > 0.05), while among those aged >8 years, it was positively correlated with age (P < 0.01). CVV/CSV ratio was positively correlated with ChT and age (both P < 0.01).

CONCLUSION

After the age of 8, age was positively correlated with CVI. ChT was well correlated with CVI. Longer AL and thinner ChT were associated with reduced CVV and CSV, with CVV decreasing more rapidly than CSV.

Genetic correlation and causal relationship between sleep and myopia: a mendelian randomization study

Purpose

To investigate the genetic correlation and causal links between sleep traits (including sleep duration, chronotype, and insomnia) and myopia.

Methods

Summary data on three sleep traits (sleep duration, chronotype and insomnia) and myopia from FinnGen (n = 214,211) and UK Biobank (n = 460,536) were analyzed using linkage disequilibrium score regression (LD Score), univariable and multivariable mendelian randomization (MR) experiments and Causal Analysis Using Summary Effect (CAUSE) estimation.

Results

LD Score regression detected candidate genetic correlation between sleep traits and myopia, such as sleep duration, chronotype (Genetic Correlation Z-score >10.00, h2_observed_p < 0.005, Lambda GC > 1.05, p > 0.05). Univariable MR analyses indicated that increased sleep duration has a promotional effect on the occurrence of myopia (p = 0.046 < 0.05, P_FDR = 0.138 < 0.2, OR = 2.872, 95% CI: 1.018-8.101). However, after accounting for potential confounding factors, multivariable MR and CAUSE analysis did not provide evidence for a causal effect of the three sleep traits on myopia.

Conclusion

There may be a potential genetic correlation between sleep duration, chronotype and myopia. However, neither of sleep duration, chronotype or insomnia had causal effect on myopia.

Refractive Errors, Amplitude of Accommodation, and Myopia Progression in Kazakhstani Medical Students: 5-Year Follow-Up

Background/Objectives: this longitudinal study aimed to investigate the refractive errors, the amplitude of accommodation, and myopia progression in Kazakhstani medical students as they progressed from the first to the fifth course of their studies. Methods: A total of 696 students from Semey Medical University underwent non-cycloplegic and cycloplegic autorefraction in the first course, and 655 were available for examination in the fifth year of study. The amplitude of accommodation was measured before the instillation of cycloplegics using the push-up and push-down methods. A self-administered questionnaire was applied to evaluate the risk factors associated with myopia progression. Results: In the first course, the median spherical equivalent was -0.75 Diopters before cycloplegia and -0.25 Diopters after cycloplegia. In the fifth course, it constituted -1.125 Diopters before cycloplegia and -0.5 Diopters after cycloplegia. The proportion of students with myopia following cycloplegic refraction increased from 44.7% in the first course to 47.5% in the fifth course. The proportion of emmetropic students declined from 31.5% to 30.3%, and hyperopia decreased from 23.8% to 16.8%. The dioptric power of accommodative excess increased from 0.375 in the first year to 0.50 in the fifth year. The hours spent on near-work activities, such as reading books, writing, working at a computer, and using a mobile device, were significantly associated with a myopia progression of ≥0.5 Diopters. Conclusions: the findings of this study suggest implications for public health policy and educational practice.

Interventional Study on the Effectiveness of Eye Exercises Based on Composite Feedback Model in School-Age Children

Objective

This study aims to explore the effects of eye exercises on the accommodative ability of Chinese school-aged children.

Methods

This study used a convenience cluster sampling and selected 149 students from grades 2-5 in a Wenzhou primary school to participate in the intervention in June 2022. This study involved a one-month intervention teaching eye exercises using a composite feedback model. Assessments were made at 3 and 9 months post-intervention. Data collection occurred thrice, including a baseline and two follow-ups, measuring monocular and binocular accommodative facility, monocular and binocular accommodative amplitude, CISS scale, spherical equivalent refraction, and uncorrected visual acuity. Analysis used chi-square tests and generalized estimating equations to evaluate the exercises' effectiveness, with a significance threshold of P < 0.05.

Results

134 students completed the follow-up, including 61 females (45.52%). After teaching intervention, students showed significant improvements in the accuracy of manipulation, rhythm, acupoint location, strength effectiveness and rhythm of acupressure eye exercises (all P < 0.05), with increases of 10.37%, 13.03%, 16.96%, and 25.17%, respectively. Follow-up assessments revealed both monocular and binocular accommodative amplitude at T3 were significantly higher than at T1 and T2. Moreover, the binocular accommodative amplitude in the high-quality eye exercise group remained significantly higher than that in the low-quality group even(B=1.39,1.46, P < 0.01). Eye exercises could improve monocular and binocular accommodative amplitude in the short term(P < 0.05). High-quality eye exercises could alleviate visual fatigue (B=-2.00--3.49, both P < 0.05). However, eye exercises did not demonstrate any advantages in affecting spherical equivalent refraction or uncorrected visual acuity (P > 0.05).

Conclusion

Eye exercises can alleviate myopia-related symptoms in Chinese children aged 7 to 11 years. However, this study did not find that eye exercises effectively reduce the degree of myopia in children.

Trial Registration

The original trial (Registration site: https://www.chictr.org.cn/ Registration number: ChiCTR2300070903) was retrospectively registered on 26/04/2023.

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.

Myopia and Rate of Peripapillary Retinal Nerve Fiber Layer Thickness in Diabetic Patients Without Retinopathy: A 2-Year Longitudinal Study

PURPOSE

The aim of this study was to investigate the association between myopia and longitudinal changes in peripapillary retinal nerve fiber layer (pRNFL) thickness in type 2 diabetic patients without diabetic retinopathy (DR).

METHODS

A total of 1069 participants with a median follow-up time of 1.9 years were included in this study. The participants were categorized into four groups based on the presence of myopia (≤ -0.5 diopter [D]) and diabetes without DR, including a control group (n = 412), diabetes group (n = 416), myopia group (n = 115), and diabetes + myopia group (n = 126). Peripapillary average and sectoral RNFL measurements were obtained using 6 × 6 mm swept-source optical coherence tomography (SS-OCT) scans centered at the optic disc. The change rate of pRNFL, adjusted for age and sex, was calculated and compared among the four groups to investigate the impact of myopia and diabetes.

RESULTS

The baseline estimated pRNFL thickness after adjustment for covariates was 113.7 μm, 116.2 μm, 108.0 μm, and 105.6 μm in the control, diabetes, myopia, and diabetes + myopia group, respectively (diabetes > control > myopia = diabetes + myopia, p < 0.001). The respective average pRNFL loss in the four groups was -0.48 μm/year, -1.11 μm/year, -1.23 μm/year, and -2.62 μm/year (all p < 0.01). The diabetes + myopia group exhibited a greater rate of average pRNFL reduction compared to the other groups (all p < 0.001). Multivariate analysis using a linear mixed-effects model showed that age, diabetes, axial length (AL), and baseline pRNFL thickness were significantly associated with the rate of average pRNFL reduction.

CONCLUSIONS

The diabetes group showed a faster rate of average pRNFL thickness reduction compared to healthy controls, regardless of the presence of myopia. The average pRNFL thickness decreased more rapidly when diabetes and myopia were present simultaneously than in the individual diabetes or myopia group. Both diabetes and myopia were associated with accelerated pRNFL loss.

Assessment of OCT-Based Macular Curvature and Its Relationship with Macular Microvasculature in Children with Anisomyopia

INTRODUCTION

To evaluate the intraocular differences in optical coherence tomography (OCT)-based macular curvature index (MCI) among children with anisomyopia and to investigate the relationship between MCI and the macular microvasculature.

METHODS

Fifty-two schoolchildren with anisometropia > 2.00 D were enrolled and underwent comprehensive examinations including cycloplegic refraction, axial length (AL), and swept source OCT/OCT angiography. OCT-based MCIs were determined from horizontal and vertical B-scans by a customized curve fitting model in MATLAB R2022 at 1-mm-, 3-mm-, and 6-mm-diameter circles at fovea. Characteristics and topographic variation of MCI was analyzed, and the relationships with microvascularity and its associated factors were investigated.

RESULTS

MCI achieved high reliability and repeatability. There were overall larger MCIs in the more myopic eyes than the less myopic eyes in 1-mm-, 3-mm-, and 6-mm-diameter circles at fovea (all p < 0.001). For the topographic variation, horizontal MCI was significantly greater than vertical MCI (all p < 0.001), and was the largest in 6-mm circle, followed by 3-mm and 1-mm circles. Stronger correlation of horizontal MCI with myopic severity than vertical MCI was found. Partial Pearson's correlation found MCI was negatively associated with deep capillary plexus (DCP) vessel density (p = 0.016). Eyes with a higher MCI in a 6-mm circle were more likely to have longer AL (p < 0.001), lower DCP vessel density (p = 0.037), and thinner choroidal thickness (ChT) (p = 0.045).

CONCLUSION

Larger MCI was found in the more myopic eyes of children with anisomyopia and was significantly associated with smaller DCP density, suggesting that MCI was an important indicator of myopia-related retinal microvascularity change, and it could be a valuable metric for myopia assessment in children.

Repeatability and Agreement of Central Vault for Implantable Collamer Lens Obtained by the Tomey OA-2000 Biometer and Spectralis OCT

Objective

To assess repeatability and agreement of central vault for implantable collamer lens (ICL) measured by the Tomey OA-2000 biometry and Spectralis optical coherence tomography (OCT).

Methods

In this prospective study, the central vault was measured by the Tomey OA-2000 biometer and Spectralis OCT in 84 eyes (43 patients) after ICL implantation at six month follow-up. Three consecutive scans were obtained by one experienced technician using Tomey OA-2000 and the Spectralis OCT in the same day. The coefficient of variation (CoV), intraclass correlation coefficient (ICC), within-subject standard deviation (Sw), and 2.77 Sw were calculated to assess the repeatability and reproducibility. The paired t-test and Bland-Altman plots were used to analyze the differences and agreements of central vault measured by two devices.

Results

Repeatability of the central vault measured by Tomey OA-2000 biometer and Spectralis OCT showed that the CoV was 2.71% and 1.66%, respectively. The ICC for both devices was 0.996 and 0.999, respectively. The paired t-test showed that central vault measured by Tomey OA-2000 biometer was -7.25 ± 23.57 microns lower than that measured by Spectralis OCT (P = 0.006). The mean difference between measurements for Tomey OA-2000 and ASM-OCT with 95% limits of agreement (LoAs) was -38.94 to 53.44 μm.

Conclusion

Both Tomey OA-2000 biometer and Spectralis OCT displayed good repeatability for the measurement of central vault of ICL. Good reliability and agreement were observed between Tomey OA-2000 biometer and Spectralis OCT. Both instruments are useful but not replaced each other for central vault measurements.

Prognostic factors for intravitreal conbercept in the treatment of choroidal neovascularization secondary to pathological myopia

PURPOSE

To identify risk factors influencing visual outcomes in patients with pathological myopia-associated choroidal neovascularization (PM-CNV) following intravitreal injections of conbercept.

METHODS

A total of 86 eyes from 86 patients received intravitreal conbercept in a 1 + PRN regimen. After the initial injection, patients were followed for 12 months. They were categorized into two groups based on their 12-month visual acuity change: those who achieved greater than a one-line improvement in BCVA (improved group; n = 65) and those who experienced a one-line or lesser improvement or a decrease in BCVA (non-improved group; n = 21).

RESULTS

Over the 12-month period, the mean BCVA in the improved group significantly improved from 0.82 to 0.41 LogMAR. In the non-improved group, BCVA changed from 1.24 to 1.09 LogMAR. Similarly, the mean CRT decreased from 426.21 μm at baseline to 251.56 μm at 12 months in the improved group, and from 452.47 to 382.45 μm in the non-improved group. Multivariable logistic regression analyses revealed that older age (OR 1.287; 95% CI 1.019-1.625; P = 0.034), poorer baseline BCVA (OR 6.422; 95% CI 1.625-25.384; P = 0.008), the presence of subfoveal CNV (OR 4.817; 95% CI 1.242-18.681; P = 0.023), and organized interlacing patterns of CNV morphology (OR 5.593; 95% CI 1.397-22.392; P = 0.015) emerged as independent risk factors correlated with worsened visual prognosis following intravitreal conbercept injections.

CONCLUSIONS

Conbercept demonstrates significant efficacy and safety in treating PM-CNV. Key factors influencing visual recovery post-treatment include older age, poorer baseline BCVA, the presence of subfoveal CNV, and organized interlacing patterns of CNV morphology.

Socioeconomic disparities and green space associated with myopia among Chinese school-aged students: A population-based cohort study

Background

There is increasing evidence on the link between environmental factors and myopia in children and adolescents, yet with inconsistent conclusions. We investigated the associations between socioeconomic inequalities and green space with myopia in school-aged students participating in the Tianjin Child and Adolescent Research of Eye (TCARE) study.

Methods

We obtained data from a population-based dynamic cohort study conducted in Tianjin, China, in 2021 and followed up in 2022. We included 1 245 271 participants from 16 districts with an average age of 11.6 years (standard deviation = 3.3) in our analysis. We synthesized their area-level SES through a prediction model that combined economic, educational, and health care variables and assessed the greenness levels surrounding the school using the Normalized Difference Vegetation Index (NDVI) based on data obtained through satellite remote sensing. We performed generalised linear mixed effects analyses for each myopia outcome separately, with adjustments for students' sex, years of education completed, and the school's geographical location.

Results

We observed that students living in low SES areas had the highest prevalence of myopia (60.7%) in the last screening in 2022, as well as a higher incidence of one-year myopia (26.4%) compared to those residing in middle SES areas (22.7%). With a 0.1 increase in the 250, 500, and 1000 m buffer NDVI, the prevalence of myopia dropped by 6.3% (odds ratio (OR) = 0.937; 95% confidence interval (CI) = 0.915, 0.960), 7.7% (OR = 0.923; 95% CI = 0.900, 0.946), and 8.7% (OR = 0.913; 95% CI = 0.889, 0.937), respectively. The interaction analysis showed that low SES and low greenness exacerbate the prevalence of myopia. Findings from longitudinal analyses consistently demonstrated a correlation between higher values of NDVI and a slower progression of myopia. These findings remained robust across sensitivity analyses, including for variables on parental myopia and students' behaviors.

Conclusions

Exposure to green spaces could play a crucial role in slowing the progression of myopia among school-aged students. Myopia control policies should prioritise young populations residing in low SES areas with limited access to green spaces, as they face the highest potential risks.

A Look into Ocular Diseases: The Pivotal Role of Omics Sciences in Ophthalmology Research

Precision medicine is a new medical approach which considers both population characteristics and individual variability to provide customized healthcare. The transition from traditional reactive medicine to personalized medicine is based on a biomarker-driven process and a deep knowledge of biological mechanisms according to which the development of diseases occurs. In this context, the advancements in high-throughput omics technologies represent a unique opportunity to discover novel biomarkers and to provide an unbiased picture of the biological system. One of the medical fields in which omics science has started to be recently applied is that of ophthalmology. Ocular diseases are very common, and some of them could be highly disabling, thus leading to vision loss and blindness. The pathogenic mechanism of most ocular diseases may be dependent on various genetic and environmental factors, whose effect has not been yet completely understood. In this context, large-scale omics approaches are fundamental to have a comprehensive evaluation of the whole system and represent an essential tool for the development of novel therapies. This Review summarizes the recent advancements in omics science applied to ophthalmology in the last ten years, in particular by focusing on proteomics, metabolomics and lipidomics applications from an analytical perspective. The role of high-efficiency separation techniques coupled to (high-resolution) mass spectrometry ((HR)MS) is also discussed, as well as the impact of sampling, sample preparation and data analysis as integrating parts of the analytical workflow.

The association between screen time exposure and myopia in children and adolescents: a meta-analysis

OBJECTIVE

This study aimed to systematically review epidemiological evidence on associations between screen time exposure and myopia in children and adolescents, and to quantitatively evaluate summary effect estimates from existing literature.

METHOD

There were three online databases including PubMed, Embase, and Web of Science, for epidemiological studies on screen time exposure and myopia published before June 1, 2023. The risk of bias was assessed by the Newcastle Ottawa Scale (NOS) checklist. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the correlation between screen time exposure and myopia using random or fixed-effect models by exposure type (categorical/continuous). We also performed subgroup analysis by screen device type, study quality, geographic region, and research period.

RESULTS

We searched 7,571 records from three databases and identified 19 eligible studies, including 14 high-quality studies and 5 moderate-quality studies. Meta-analyses suggested that there was a statistically significant correlation between screen time (high vs. low) and myopia. The pooled ORs with 95%CIs were respectively 2.24 (1.47-3.42) for cross-sectional studies, and 2.39 (2.07-2.76) for cohort studies. We also found a significant association between continuous exposure to screen time (per 1 h/d increase) and myopia in cohort studies. The pooled ORs with 95%CIs were 1.07 (1.01-1.13). In subgroup analysis stratified by screen device type in cross-sectional studies, screen time exposures from computers (categorical: OR = 8.19, 95%CI: 4.78-14.04; continuous: OR = 1.22, 95%CI: 1.10-1.35) and televisions (categorical: OR = 1.46, 95%CI: 1.02-2.10) were associated with myopia, while smartphones were not. Although publication bias was detected, the pooled results did not show significant changes after adjustment using the trim and fill method.

CONCLUSION

Our findings support that screen time exposure was significantly associated with myopia in children and adolescents. Notably, screen time exposure from computers may have the most significant impact on myopia.

No Evidence of an Association between Genetic Factors Affecting Response to Vitamin A Supplementation and Myopia: A Mendelian Randomization Study and Meta-Analysis

The relationship between vitamin A supplementation and myopia has been a topic of debate, with conflicting and inconclusive findings. We aimed to determine whether there is a causal relationship between vitamin A supplementation and the risk of myopia using Mendelian randomization (MR) and meta-analytical methods. Genetic variants from the UK Biobank and FinnGen studies associated with the response to vitamin A supplementation were employed as instrumental variables to evaluate the causal relationship between vitamin A supplementation and myopia. Fixed-effects meta-analysis was then used to combine MR estimates from multiple sources for each outcome. The meta-analysis of MR results found no convincing evidence to support a direct causal relationship between vitamin A supplementation and myopia risk (odds ratio (OR) = 0.99, 95% confidence interval (CI) = 0.82-1.20, I2 = 0%, p = 0.40). The analysis of three out of the four sets of MR analyses indicated no direction of causal effect, whereas the other set of results suggested that higher vitamin A supplementation was associated with a lower risk of myopia (OR = 0.002, 95% CI 1.17 × 10-6-3.099, p = 0.096). This comprehensive MR study and meta-analysis did not find valid evidence of a direct association between vitamin A supplementation and myopia. Vitamin A supplementation may not have an independent effect on myopia, but intraocular processes associated with vitamin A may indirectly contribute to its development.

The burden, causes, and determinants of blindness and vision impairment in Asia: An analysis of the Global Burden of Disease Study

Background

Asia accounts for more than half of the world's population and carries a substantial proportion of the global burden of blindness and vision impairment. Characterising this burden, as well as its causes and determinants, could help with devising targeted interventions for reducing the occurrence of blindness and visual impairment.

Methods

Using the Global Burden of Disease Study 2019 database, we retrieved data on the number of disability-adjusted life years (DALYs); crude and age-standardised rates; and the prevalence (with 95% uncertainty intervals (95%UIs)) of blindness and vision loss due to six causes (age-related macular degeneration, cataracts, glaucoma, near-vision impairment, refractive error, and other vision loss) for Asian countries for the period between 1990 and 2019. We defined DALYs as the sum of the years lost due to disability and years of life lost, and calculated age-standardised figures for the number of DALYs and prevalence by adjusting for population size and age structure. We then evaluated the time trend of the disease burden and conducted subgroup analyses by gender, age, geographic locations, and socio-demographic index (SDI).

Results

In 2019, the DALYs and prevalence of blindness and vision loss had risen by 90.1% and 116% compared with 1990, reaching 15.84 million DALYs (95% UI = 15.83, 15.85) and 506.71 million cases (95% UI = 506.68, 506.74). Meanwhile, the age-standardised rate of DALYs decreased from 1990 to 2019. Cataracts, refractive error, and near vision impairment were the three most common causes. South Asia had the heaviest regional disease burden (age-standardised rate of DALYs = 517 per 100 000 population; 95% UI = 512, 521). Moreover, the burden due to cataracts ranked high in most Asian populations. Being a woman; being older; and having a lower national SDI were factors associated with a greater vision loss burden.

Conclusions

The burden due to vision loss remains high in Asian populations. Cataracts, refractive error, and near vision loss were the primary causes of blindness and vision loss. Greater investment in ocular disease prevention and care by countries with lower socioeconomic status is needed, as well as specific strategies targeting cataract management, women and the elderly.

Identification of LRRC46 as a novel candidate gene for high myopia

High myopia (HM) is the primary cause of blindness, with the microstructural organization and composition of collagenous fibers in the cornea and sclera playing a crucial role in the biomechanical behavior of these tissues. In a previously reported myopic linkage region, MYP5 (17q21-22), a potential candidate gene, LRRC46 (c.C235T, p.Q79X), was identified in a large Han Chinese pedigree. LRRC46 is expressed in various eye tissues in humans and mice, including the retina, cornea, and sclera. In subsequent cell experiments, the mutation (c.C235T) decreased the expression of LRRC46 protein in human corneal epithelial cells (HCE-T). Further investigation revealed that Lrrc46-/- mice (KO) exhibited a classical myopia phenotype. The thickness of the cornea and sclera in KO mice became thinner and more pronounced with age, the activity of limbal stem cells decreased, and microstructural changes were observed in the fibroblasts of the sclera and cornea. We performed RNA-seq on scleral and corneal tissues of KO and normal control wild-type (WT) mice, which indicated a significant downregulation of the collagen synthesis-related pathway (extracellular matrix, ECM) in KO mice. Subsequent in vitro studies further indicated that LRRC46, a member of the important LRR protein family, primarily affected the formation of collagens. This study suggested that LRRC46 is a novel candidate gene for HM, influencing collagen protein VIII (Col8a1) formation in the eye and gradually altering the biomechanical structure of the cornea and sclera, thereby promoting the occurrence and development of HM.

Repeated Low-Level Red Light Therapy for Myopia Control in High Myopia Children and Adolescents: A Randomized Clinical Trial

PURPOSE

To assess the effectiveness and safety of repeated low-level red light (RLRL), which is a newly available treatment for myopia control in children and adolescents with high myopia.

DESIGN

Multicenter, randomized, parallel-group, single-blind clinical trial (randomized controlled trial; NCT05184621).

PARTICIPANTS

Between February 2021 and April 2022, 192 children aged 6 to 16 years were enrolled. Each child had at least 1 eye with myopia of cycloplegic spherical equivalent refraction (SER) at least -4.0 diopters (D), astigmatism of ≤2.0 D, anisometropia of ≤3.0 D, and best-corrected visual acuity (BCVA) of 0.2 logarithm of the minimum angle of resolution or better. Follow-up was completed by April 2023.

METHODS

Participants were randomly assigned at a 1:1 ratio to intervention (RLRL treatment plus single-vision spectacles) or control (single-vision spectacles) groups. The RLRL treatment was administered for 3 minutes per session, twice daily with a minimum interval of 4 hours, 7 days per week.

MEAN OUTCOME MEASURES

The primary outcome and key secondary outcome were changes in axial length (AL) and cycloplegic SER measured at baseline and the 12-month follow-up visit. Participants who had at least 1 postrandomization follow-up visit were analyzed for treatment efficacy.

RESULTS

Among 192 randomized participants, 188 (97.91%) were included in the analyses (96 in the RLRL group and 92 in the control group). After 12 months, the adjusted mean change in AL was -0.06 mm (95% confidence interval [CI], -0.10 to -0.02 mm) and 0.34 mm (95% CI, 0.30 to 0.39 mm) in the intervention and control groups, respectively. A total of 48 participants (53.3%) in the intervention group were still experiencing axial shortening >0.05 mm at the 12-month follow-up. The mean SER change after 12 months was 0.11 D (95% CI, 0.02to 0.19 D) and -0.75 D (95% CI, -0.88 to -0.62 D) in the intervention and control groups, respectively.

CONCLUSIONS

Repeated low-level red light demonstrates stronger treatment efficacy among those with high myopia, with 53.3% experiencing substantial axial shortening. Repeated low-level red light provides an excellent solution for the management of high myopia progression, a significant challenge in ophthalmology practice.

FINANCIAL DISCLOSURE(S)

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

The Myopia Prevalence and Association With Physical Activity Among Primary School Students Aged 6-12 Years: A Cross-Sectional Study in Tianjin, China

Purpose

This study aimed to investigate the prevalence of myopia and determine the association between physical activity and risk of myopia among primary school students in Tianjin, China.

Methods

A cross-sectional study was conducted among subjects from nine primary schools. All of the subjects underwent visual acuity and spherical equivalent (SE) with noncycloplegic autorefraction measurement. Myopia was defined as an SE refraction ≤-0.50D and an uncorrected visual acuity <5.0 in either eye. Physical activity was measured via the Physical Activity Questionnaire for Children. Data were analyzed using the Pearson χ2 test and binary logistic regression. Stratification analysis by sex was also performed.

Results

A total of 2976 participants (1408 boys and 1568 girls) aged six to 12 years (mean age 8.82 years) were included in this study. The overall prevalence of myopia was 52.92%. When stratified according to physical activity, myopia prevalence significantly decreased with increasing physical activity levels (χ2 trend test = 127.63, P < 0.001). In the binary logistic regression analysis, after adjusting for age, sex, and school region, the odds ratio for the association between physical activity and myopia was 0.762 (95% confidence interval, 0.675-0.862, P < 0.001). When stratified by sex, the significant statistical association between physical activity and myopia both can be found in two groups (P < 0.05).

Conclusions

Higher levels of physical activity were independently associated with decreased risk of myopia. The significant reverse statistical association between physical activity and myopia can be found in male or female groups.

Translational Relevance

Taking part in physical activities may be an effective way to reduce the prevalence of myopia.

Effect of Low-Concentration Atropine Eye Drops in Controlling the Progression of Myopia in Children: A One- and Two-Year Follow-Up Study

PURPOSE

Atropine eye drops have been shown to slow the progression of myopia, but there has been limited research on the effectiveness of 0.05% atropine in treating myopia. This study aimed to investigate the safety and efficacy of 0.05% atropine eye drops in controlling myopia in children.

METHODS

The study included 424 participants aged 6 to 12 years between January 1, 2015, and January 1, 2021. Of these, 213 were randomly assigned to the 0.05% atropine group and 211 to the placebo group. The cycloplegic spherical equivalent (SE), axial length (AL), corneal curvature (K), and anterior chamber depth (ACD) were measured using IOLMaster. The lens power and corneal astigmatism were also determined. The changes in ocular biometric parameters were compared between the two groups, and the contributions of ocular characteristics to SE progression were calculated and compared.

RESULTS

Over a 12-month period, the changes in spherical equivalent were -0.03 ± 0.28 and -0.32 ± 0.14 in the atropine and placebo groups, respectively (P = .01). The changes in axial length were 0.06 ± 0.11 and 0.17 ± 0.12, respectively (P = .01). At 18 and 24 months, there were significant differences in axial length and spherical equivalent between the atropine and placebo groups. Multiple regression models accounting for changes in AL, K, and lens magnification explained 87.23% and 98.32% of SE changes in the atropine and placebo groups, respectively. At 1 year (p = .01) and 2 years (p = .03), there were significant differences in photophobia between the atropine and placebo groups.

CONCLUSIONS

This two-year follow-up study demonstrates that 0.05% atropine eye drops are safe and effective in preventing the development of myopia in school-aged children.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of trial lens and computer-aided fitting in orthokeratology: A multi-center, randomized, examiner-masked, controlled study

PURPOSE

To compare the efficacy and safety between traditional lens fitting and computer-aided fitting methods for orthokeratology (OrthoK) in the Chinese population.

METHODS

A multi-center, examiner-masked, randomized controlled study was conducted with a one-year follow-up period, enrolling 280 participants with spherical equivalent (SE) ranging from -0.5D to -4.0D. Participants were assigned to either the computer-aided orthokeratology fitting group (trial group) or the traditional lens fitting group (control group) using stratified randomization based on age (8 to 13 years, 13 to 18 years, and ≥ 18 years) to ensure a minimum of 30 cases in each sub-age group. Ocular examinations included visual acuity, objective and subjective refraction, corneal endothelial cell density, corneal topography, intraocular pressure, axial length, and ocular health assessment. Successful lens-correction was defined as the residual refraction with the OK lens, which should not exceed ± 0.5D, and/or an uncorrected visual acuity of no worse than 0.1 logMAR. Statistical analysis involves t-tests, analysis of variance, and Chi-squared tests.

RESULTS

215 subjects were included in the statistical analysis (109 in the trial group and 106 in the control group). In both groups, compared to baseline data, the uncorrected visual acuity (UCVA) improved significantly, with SE reduced and central corneal curvature flattened greatly after wearing OrthoK lens (P < 0.05 for all). Compared to the control group, the trial group exhibited a higher successful rate in correcting UCVA (93.6 % vs. 84.0 %, P = 0.03) and slightly better correction in refraction (77.1 % vs. 66.0 %, P = 0.07) at 1-month follow-up. However, no significant differences were observed in the axial length elongation, corneal changes, or the incidence of adverse events between the two groups.

CONCLUSION

These findings indicate the higher efficiency and slightly better performance in correcting myopia and improving UCVA of computer-aided lens fitting approach compared to the traditional one, but similar outcomes in controlling axial elongation.

Trio-based whole-exome sequencing reveals mutations in early-onset high myopia

PURPOSE

Myopia, especially high myopia (HM), represents a widespread visual impairment with a globally escalating prevalence. This study aimed to elucidate the genetic foundations associated with early-onset HM (eoHM) while delineating the genetic landscape specific to Shaanxi province, China.

METHODS

A comprehensive analysis of whole-exome sequencing was conducted involving 26 familial trios displaying eoHM. An exacting filtration protocol identified potential candidate mutations within acknowledged myopia-related genes and susceptibility loci. Subsequently, computational methodologies were employed for functional annotations and pathogenicity assessments.

RESULTS

Our investigation identified 7 genes and 10 variants associated with HM across 7 families, including a novel mutation in the ARR3 gene (c.139C>T, p.Arg47*) and two mutations in the P3H2 gene (c.1865T>C, p.Phe622Ser and c.212T>C, p.Leu71Pro). Pathogenic mutations were found in syndromic myopia genes, notably encompassing VPS13B, TRPM1, RPGR, NYX and RP2. Additionally, a thorough comparison of previously reported causative genes of syndromic myopia and myopia risk genes with the negative sequencing results pinpointed various types of mutations within risk genes.

CONCLUSIONS

This investigation into eoHM within Shaanxi province adds to the current understanding of myopic genetic factors. Our results warrant further functional validation and ocular examinations, yet they provide foundational insights for future genetic research and therapeutic innovations in HM.

Prevalence of myopia among children and adolescents aged 6-16 during COVID-19 pandemic: a large-scale cross-sectional study in Tianjin, China

PURPOSE

This study aimed to determine the prevalence of myopia among children and adolescents aged 6-16 years during COVID-19 pandemic in Tianjin, China.

METHODS

This was a cross-sectional study using data from the Tianjin Child and Adolescent Research of Eye between March and June in 2021. A total of 909 835 children and adolescents aged 6-16 years from 1348 primary and secondary schools in Tianjin, China were recruited. Prevalence of myopia with 95% CIs was described in different regions, sexes and ages. The regions-standardised prevalence rate and chain growth rate of myopia in different ages were described the characteristics of myopia.

RESULTS

A total of 864 828 participants (95.05% participation rate) were included in the analysis. The age range was 6-16 with a mean age of 11.50±2.79 years. The overall prevalence of myopia was 54.71% (95% CI 54.60% to 54.81%). The prevalence of myopia was 57.58% (95% CI 57.43% to 57.73%) for girls and 52.05% (95% CI 51.91% to 52.20%) for boys. Students living in the six central districts had the highest prevalence of moderate myopia (19.09% (95% CI 19.01% to 19.17%)) and high myopia (5.43% (95% CI 5.39% to 5.48%)). The regions-standardised prevalence of myopia was increased by age and the highest chain growth rate of myopia was up to 47.99% at 8 years.

CONCLUSIONS

The prevalence of myopia in Tianjin is high during COVID-19 pandemic. The progression of myopia started to increase dramatically at 8 years, and the increasing slowed down at 14 years. For policy-makers, intervention in the lower age groups may be important to control myopia progression.

Effect of exogenous calcitriol on myopia development and axial length in guinea pigs with form deprivation myopia

The annual increase in myopia prevalence poses a significant economic and health challenge. Our study investigated the effect of calcitriol role in myopia by inducing the condition in guinea pigs through form deprivation for four weeks. Untargeted metabolomics methods were used to analyze the differences in metabolites in the vitreous body, and the expression of vitamin D receptor (VDR) in the retina was detected. Following form deprivation, the guinea pigs received intraperitoneal injections of calcitriol at different concentrations. We assessed myopia progression using diopter measurements and biometric analysis after four weeks. Results indicated that form deprivation led to a pronounced shift towards myopia, characterized by reduced choroidal and scleral thickness, disorganized collagen fibers, and decreased scleral collagen fiber diameter. Notably, a reduction in calcitriol expression in vitreous body, diminished vitamin D and calcitriol levels in the blood, and decreased VDR protein expression in retinal tissues were observed in myopic guinea pigs. Calcitriol administration effectively slowed myopia progression, preserved choroidal and scleral thickness, and prevented the reduction of scleral collagen fiber diameter. Our findings highlight a significant decrease in calcitriol and VDR expressions in myopic guinea pigs and demonstrate that exogenous calcitriol supplementation can halt myopia development, enhancing choroidal and scleral thickness and scleral collagen fiber diameter.

The knowledge structure and research trends between light and myopia: A bibliometric analysis from 1981 to 2024

BACKGROUND

This bibliometric analysis explored the knowledge structure of and research trends in the relationship between light and myopia.

METHODS

Relevant literature published from 1981 to 2024 was collected from the Web of Science Core Collection database. Visual maps were generated using CiteSpace and VOSviewer. We analyzed the included studies in terms of the annual publication count, countries, institutional affiliations, prolific authors, source journals, top 10 most cited articles, keyword co-occurrence, and cocitations.

RESULTS

A total of 525 papers examining the relationship between light and myopia published between 1981 and 2024 were collected. The United States ranked first in terms of the number of publications and actively engaged in international cooperation with other countries. The New England College of Optometry, which is located in the United States, was the most active institution and ranked first in terms of the number of publications. Schaeffel Frank was the most prolific author. The most active journal in the field was Investigative Ophthalmology & Visual Science. The most frequently cited paper in the included studies was written by Saw, SM and was published in 2002. The most common keywords in basic research included "refractive error," "longitudinal chromatic aberration," and "compensation." The most common keywords in clinical research mainly included "light exposure," "school," and "outdoor activity." The current research hotspots in this field are "progression," "refractive development," and "light exposure." The cocitation analysis generated 17 clusters.

CONCLUSION

This study is the first to use bibliometric methods to analyze existing research on the relationship between light and myopia. In recent years, the intensity and wavelength of light have become research hotspots in the field. Further research on light of different intensities and wavelengths may provide new perspectives in the future for designing more effective treatments and interventions to reduce the incidence of myopia.

Comparison of macular changes and visual outcomes between femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery for high myopic cataract patients

BACKGROUND

To evaluate differences in log MAR best-corrected visual acuity (BCVA) improvement and postoperative central foveal thickness (CFT) and choroidal thickness (CT) changes between conventional phacoemulsification surgery (CPS) and femtosecond laser-assisted cataract surgery (FLACS) for high-myopia cataracts.

METHODS

This was a retrospective and observational study. One hundred and two eyes of 102 patients with high-myopia cataracts were examined. CPS was performed in 54 eyes, and FLACS was performed in 48 eyes. All eyes underwent logMAR BCVA, CFT and CT of three different sectors preoperatively and one week and six months postoperatively.

RESULTS

The logMAR BCVA improved significantly after surgery in both groups (both P < 0.001), but no difference was observed in BCVA improvement between the groups (P = 0.554). Moreover, no significant differences were reflected in the changes in CFT, nasal 1 mm CT or temporal 1 mm CT between the two groups, and only subfoveal choroidal thickness (SFCT) in the CPS group decreased significantly compared with that in the FLACS group at any postoperative time (P = 0.003 and 0.026). AL, preoperative logMAR BCVA, and CT of the three regions exhibited a notable correlation with postoperative BCVA (all P < 0.05) according to univariate logistic regression analysis. However, only the AL, preoperative logMAR BCVA and SFCT remained significant in the multivariate model. Postoperative logMAR BCVA revealed a positive correlation with AL and preoperative logMAR BCVA but a negative correlation with SFCT.

CONCLUSIONS

FLACS was not superior to CPS in improving BCVA but had less impact on SFCT in the treatment of high-myopia cataracts. Eyes with a longer AL, worse preoperative logMAR BCVA and thinner SFCT had a high risk of worse postoperative BCVA.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Development and validation of a deep learning model to predict axial length from ultra-wide field images

BACKGROUND

To validate the feasibility of building a deep learning model to predict axial length (AL) for moderate to high myopic patients from ultra-wide field (UWF) images.

METHODS

This study included 6174 UWF images from 3134 myopic patients during 2014 to 2020 in Eye and ENT Hospital of Fudan University. Of 6174 images, 4939 were used for training, 617 for validation, and 618 for testing. The coefficient of determination (R2), mean absolute error (MAE), and mean squared error (MSE) were used for model performance evaluation.

RESULTS

The model predicted AL with high accuracy. Evaluating performance of R2, MSE and MAE were 0.579, 1.419 and 0.9043, respectively. Prediction bias of 64.88% of the tests was under 1-mm error, 76.90% of tests was within the range of 5% error and 97.57% within 10% error. The prediction bias had a strong negative correlation with true AL values and showed significant difference between male and female (P < 0.001). Generated heatmaps demonstrated that the model focused on posterior atrophy changes in pathological fundus and peri-optic zone in normal fundus. In sex-specific models, R2, MSE, and MAE results of the female AL model were 0.411, 1.357, and 0.911 in female dataset and 0.343, 2.428, and 1.264 in male dataset. The corresponding metrics of male AL models were 0.216, 2.900, and 1.352 in male dataset and 0.083, 2.112, and 1.154 in female dataset.

CONCLUSIONS

It is feasible to utilize deep learning models to predict AL for moderate to high myopic patients with UWF images.

Myopia prevalence and ocular biometry in children and adolescents at different altitudes: a cross-sectional study in Chongqing and Tibet, China

OBJECTIVE

To investigate the differences in myopia prevalence and ocular biometry in children and adolescents in Chongqing and Tibet, China.

DESIGN

Cross-sectional study.

SETTING

The study included children and adolescents aged 6-18 years in Chongqing, a low-altitude region, and in Qamdo, a high-altitude region of Tibet.

PARTICIPANTS

A total of 448 participants in Qamdo, Tibet, and 748 participants in Chongqing were enrolled in this study.

METHODS

All participants underwent uncorrected visual acuity assessment, non-cycloplegic refraction, axial length (AL) measurement, intraocular pressure (IOP) measurement and corneal tomography. And the participants were grouped according to age (6-8, 9-11, 12-14 and 15-18 years group), and altitude of location (primary school students: group A (average altitude: 325 m), group B (average altitude: 2300 m), group C (average altitude: 3250 and 3170 m) and group D (average altitude: 3870 m)).

RESULTS

There was no statistical difference in mean age (12.09±3.15 vs 12.2±3.10, p=0.549) and sex distribution (males, 50.4% vs 47.6%, p=0.339) between the two groups. The Tibet group presented greater spherical equivalent (SE, -0.63 (-2.00, 0.13) vs -0.88 (-2.88, -0.13), p<0.001), shorter AL (23.45±1.02 vs 23.92±1.19, p<0.001), lower prevalence of myopia (39.7% vs 47.6%, p=0.008) and flatter mean curvature power of the cornea (Km, 43.06±1.4 vs 43.26±1.36, p=0.014) than the Chongqing group. Further analysis based on age subgroups revealed that the Tibet group had a lower prevalence of myopia and higher SE in the 12-14, and 15-18 years old groups, shorter AL in the 9-11, 12-14 and 15-18 years old groups, and lower AL to corneal radius of curvature ratio (AL/CR) in all age subgroups compared with the Chongqing group, while Km was similar between the two groups in each age subgroup. Simple linear regression analysis showed that SE decreased with age in both the Tibet and Chongqing groups, with the Tibet group exhibiting a slower rate of decrease (p<0.001). AL and AL/CR increased with age in both the Tibet and Chongqing groups, but the rate of increase was slower in the Tibet group (p<0.001 of both). Multiple linear regression analysis revealed that AL had the greatest effect on SE in both groups, followed by Km. In addition, the children and adolescents in Tibet presented thinner corneal thickness (CCT, p<0.001), smaller white to white distance (WTW, p<0.001), lower IOP (p<0.001) and deeper anterior chamber depth (ACD, p=0.015) than in Chongqing. Comparison of altitude subgroups showed that the prevalence of myopia (p=0.002), SE (p=0.031), AL (p=0.001) and AL/CR (p<0.001) of children at different altitudes was statistically different but the Km (p=0.189) were similar. The highest altitude, Tengchen County, exhibited the lowest prevalence of myopia and greatest SE among children, and the mean AL also decreased with increasing altitude.

CONCLUSIONS

Myopia prevalence in Tibet was comparable with that in Chongqing for students aged 6-8 and 9-11 years but was lower and myopia progressed more slowly for students aged 12-14 and 15-18 years than in Chongqing, and AL was the main contributor for this difference, which may be related to higher ultraviolet radiation exposure and lower IOP in children and adolescents at high altitude in Tibet. Differences in AL and AL/CR between Tibet and Chongqing children and adolescents manifested earlier than in SE, underscoring the importance of AL measurement in myopia screening.

Global prevalence of myopic macular degeneration in general population and patients with high myopia: A systematic review and meta-analysis

The prevalence of myopic macular degeneration (MMD) in the general population and patients with high myopia worldwide has not been fully investigated. Therefore, we screened all population-based studies that reported the prevalence of MMD, and pooled prevalence of MMD using a random-effect model. Subgroup analyses were performed to explore the differences in MMD prevalence in the general population and patients with high myopia according to ethnicity, region of residence (urban/rural), and grading system. Finally, 16 studies were included in this meta-analysis. Results obtained from 2,963 patients from seven countries on four continents indicated that the pooled prevalence of MMD in patients with high myopia was 49.0% (95% CI: 31.5%-66.7%). Results obtained from 71,052 participants from 10 countries on four continents suggested that the pooled prevalence of MMD in the general population was 1.7% (95% CI: 1.1%-2.6%). In the general population, living in urban areas and East Asians were associated with a high prevalence of MMD. Among patients with high myopia, only East Asians were at a higher risk of developing MMD. In conclusion, MMD was particularly prevalent in patients with high myopia. Compared with Europeans, East Asians (Chinese and Japanese) have a higher propensity of developing MMD, both in the general population and in patients with high myopia. It remains unclear whether the higher prevalence of MMD in patients with high myopia in East Asia is caused by differences in given age or given degree of myopia.Systematic review registration number: 202270014 (INPLASY.COM).

Glutathione and a Pool of Metabolites Partly Related to Oxidative Stress Are Associated with Low and High Myopia in an Altered Bioenergetic Environment

Oxidative stress forms part of the molecular basis contributing to the development and manifestation of myopia, a refractive error with associated pathology that is increasingly prevalent worldwide and that subsequently leads to an upsurge in degenerative visual impairment due to conditions that are especially associated with high myopia. The purpose of our study was to examine the interrelation of potential oxidative-stress-related metabolites found in the aqueous humor of high-myopic, low-myopic, and non-myopic patients within a clinical study. We conducted a cross-sectional study, selecting two sets of patients undergoing cataract surgery. The first set, which was used to analyze metabolites through an NMR assay, comprised 116 patients. A total of 59 metabolites were assigned and quantified. The PLS-DA score plot clearly showed a separation with minimal overlap between the HM and control samples. The PLS-DA model allowed us to determine 31 major metabolite differences in the aqueous humor of the study groups. Complementary statistical analysis of the data allowed us to determine six metabolites that presented significant differences among the experimental groups (p < 005). A significant number of these metabolites were discovered to have a direct or indirect connection to oxidative stress linked with conditions of myopic eyes. Notably, we identified metabolites associated with bioenergetic pathways and metabolites that have undergone methylation, along with choline and its derivatives. The second set consisted of 73 patients who underwent a glutathione assay. Here, we showed significant variations in both reduced and oxidized glutathione in aqueous humor among all patient groups (p < 0.01) for the first time. Axial length, refractive status, and complete ophthalmologic examination were also recorded, and interrelations among metabolic and clinical parameters were evaluated.

Development and validation of a smartwatch algorithm for differentiating physical activity intensity in health monitoring

To develop and validate a machine learning based algorithm to estimate physical activity (PA) intensity using the smartwatch with the capacity to record PA and determine outdoor state. Two groups of participants, including 24 adults (13 males) and 18 children (9 boys), completed a sequential activity trial. During each trial, participants wore a smartwatch, and energy expenditure was measured using indirect calorimetry as gold standard. The support vector machine algorithm and the least squares regression model were applied for the metabolic equivalent (MET) estimation using raw data derived from the smartwatch. Exercise intensity was categorized based on MET values into sedentary activity (SED), light activity (LPA), moderate activity (MPA), and vigorous activity (VPA). The classification accuracy was evaluated using area under the ROC curve (AUC). The METs estimation accuracy were assessed via the mean absolute error (MAE), the correlation coefficient, Bland-Altman plots, and intraclass correlation (ICC). A total of 24 adults aged 21-34 years and 18 children aged 9-13 years participated in the study, yielding 1790 and 1246 data points for adults and children respectively for model building and validation. For adults, the AUC for classifying SED, MVPA, and VPA were 0.96, 0.88, and 0.86, respectively. The MAE between true METs and estimated METs was 0.75 METs. The correlation coefficient and ICC were 0.87 (p < 0.001) and 0.89, respectively. For children, comparable levels of accuracy were demonstrated, with the AUC for SED, MVPA, and VPA being 0.98, 0.89, and 0.85, respectively. The MAE between true METs and estimated METs was 0.80 METs. The correlation coefficient and ICC were 0.79 (p < 0.001) and 0.84, respectively. The developed model successfully estimated PA intensity with high accuracy in both adults and children. The application of this model enables independent investigation of PA intensity, facilitating research in health monitoring and potentially in areas such as myopia prevention and control.

Ciliary muscles contraction leads to axial length extension--The possible initiating factor for myopia

PURPOSE

This study aimed to investigate the underlying factors driving the onset of myopia, specifically the role of the ciliary muscle's contraction in the elongation of the axial length of the eye.

METHODS

The retrospective study was conducted utilizing data from three ophthalmic centers in Shanghai and Beijing. Both Chinese and Caucasian children were involved. The axial length of the subjects' eyes was measured in both relaxed and contracted state of the ciliary muscle. A comprehensive mechanical model was also developed to observe the influence of ciliary muscle contraction on the axial length.

RESULTS

This study included a sample of 198 right eyes of 198 myopic children. Of these, 97 were male and 101 were female, 126 were of Chinese ethnicity and 72 were Caucasian. The age of onset for myopia ranged from 5.9 to 16.9 years old. The axial length of the eye decreased 0.028 ± 0.007mm following dilation, indicating relaxation of the ciliary muscle (t paired student = 15.16, p = 6.72 x 10-35). In contrast, ciliary muscle contraction resulted in an increase in axial length. Considering proportionality, a significant 90.4% (179 eyes) exhibited a reduced axial length, while a minor 9.6% (19 eyes) demonstrated an increase post-mydriasis. Finite element modeling demonstrated that muscle contraction caused a tension force that transmits towards the posterior pole of the eye, causing it to extend posteriorly.

CONCLUSION

The contraction of the ciliary muscle leads to an extension of the axial length. This could potentially be the initiating factor for myopia.

Decoding visual fatigue in a visual search task selectively manipulated via myopia-correcting lenses

Introduction

Visual fatigue resulting from sustained, high-workload visual activities can significantly impact task performance and general wellbeing. So far, however, little is known about the underlying brain networks of visual fatigue. This study aimed to identify such potential networks using a unique paradigm involving myopia-correcting lenses known to directly modulate subjectively-perceived fatigue levels.

Methods

A sample of N = 31 myopia participants [right eye-SE: -3.77D (SD: 2.46); left eye-SE: -3.75D (SD: 2.45)] performed a demanding visual search task with varying difficulty levels, both with and without the lenses, while undergoing fMRI scanning. There were a total of 20 trials, after each of which participants rated the perceived difficulty and their subjective visual fatigue level. We used representational similarity analysis to decode brain regions associated with fatigue and difficulty, analyzing their individual and joint decoding pattern.

Results and discussion

Behavioral results showed correlations between fatigue and difficulty ratings and above all a significant reduction in fatigue levels when wearing the lenses. Imaging results implicated the cuneus, lingual gyrus, middle occipital gyrus (MOG), and declive for joint fatigue and difficulty decoding. Parts of the lingual gyrus were able to selectively decode perceived difficulty. Importantly, a broader network of visual and higher-level association areas showed exclusive decodability of fatigue (culmen, middle temporal gyrus (MTG), parahippocampal gyrus, precentral gyrus, and precuneus). Our findings enhance our understanding of processing within the context of visual search, attention, and mental workload and for the first time demonstrate that it is possible to decode subjectively-perceived visual fatigue during a challenging task from imaging data. Furthermore, the study underscores the potential of myopia-correcting lenses in investigating and modulating fatigue.

Associations between corneal curvature and other anterior segment biometrics in young myopic adults

To investigate the associations between corneal curvature (CC) and other anterior segment biometrics in young myopic adults. In this retrospective multi-center study, 7893 young myopic adults were included. CC and other anterior segment biometrics were measured by Scheimpflug imaging (Pentacam). CC was defined as SimK at central 3 mm area, and other anterior segment biometrics included white-to-white corneal diameter (WTW), central corneal thickness (CCT), corneal volume (CV) at 3 mm, 5 mm, and 7 mm area, anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), anterior corneal eccentricity (ACE) and asphericity (ACAP), posterior corneal eccentricity (PCE) and asphericity (PCAP), anterior chamber depth (ACD), and anterior chamber volume (ACV). Univariate regression analyses were used to assess the associations between CC and other anterior segment biometrics, and multivariate regression analyses were further performed to adjusted for age, gender and spherical equivalent. CC was higher in patients of female gender and higher myopia (all P < 0.05). Eyes in higher CC quartiles had lower WTW, thinner CCT, lower CV at 3 mm and 5 mm, lower ACD, and lower ACV (all P < 0.001), but had larger ACA, larger PCA, less PCE and less PCAP (all P < 0.001), compared to eyes in lower CC quartiles. The trends of CV at 7 mm, ACE and ACAP were inconsistent in different CC quartiles. After adjusting for age, gender and spherical equivalent with multivariate linear regression, CC was positively correlated to CV at 7 mm (βs = 0.069), ACA (βs = 0.194), PCA (βs = 0.187), ACE (βs = 0.072), PCAP (βs = 0.087), and ACD (βs = 0.027) (all P < 0.05), but was negatively correlated to WTW (βs = - 0.432), CCT (βs = - 0.087), CV-3 mm (βs = - 0.066), ACAP (βs = - 0.043), PCE (βs = - 0.062), and ACV (βs = - 0.188) (all P < 0.05). CC was associated with most of the other anterior segment biometrics in young myopic adults. These associations are important for better understanding of the interactions between different anterior segment structures in young myopic patients, and are also useful for the exploration of the pathogenesis of myopia.

Peripapillary atrophy area predicts the decrease of macular choroidal thickness in young adults during myopia progression

OBJECTIVE

This study aimed to investigate the influence of peripapillary atrophy (PPA) area and axial elongation on the longitudinal changes in macular choroidal thickness (ChT) in young individuals with myopia.

METHODS AND ANALYSIS

In this longitudinal investigation, 431 eyes-342 categorised as non-high myopia (non-HM) and 89 as HM-were examined for 2 years. Participants were examined with swept-source optical coherence tomography. The macular ChT, PPA area and axial length (AL) were measured at baseline and follow-up visits. Multiple regression analysis was performed to identify factors associated with ChT changes. The areas under the receiver operating characteristic curves were analysed to ascertain the predictive capacity of the PPA area and axial elongation for the reduction in macular ChT.

RESULTS

Initial measurements revealed that the average macular ChT was 240.35±56.15 µm in the non-HM group and 198.43±50.27 µm in the HM group (p<0.001). It was observed that the HM group experienced a significantly greater reduction in average macular ChT (-7.35±11.70 µm) than the non-HM group (-1.85±16.95 µm, p=0.004). Multivariate regression analysis showed that a greater reduction of ChT was associated with baseline PPA area (β=-26.646, p<0.001) and the change in AL (β=-35.230, p<0.001). The combination of the baseline PPA area with the change in AL was found to be effective in predicting the decrease in macular ChT, with an area under the curve of 0.741 (95% CI 0.694 to 0.787).

CONCLUSION

Over 2 years, eyes with HM exhibit a more significant decrease in ChT than those without HM. Combining the baseline PPA area with the change in AL could be used to predict the decrease of macular ChT.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Translational Relevance

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

Different efficacy in myopia control: Comparison between orthokeratology and defocus-incorporated multiple segment lenses

PURPOSE

To compare the efficiency of orthokeratology (OK) and defocus-incorporated multiple segment (DIMS) lenses in myopia control in children.

METHODS

This prospective study involved 540 subjects (7-14 years) categorized into three groups: DIMS lenses (180 cases), OK lenses (180 cases), or single-vision spectacles (SVS) (180 cases). After a one-year follow-up, changes in axial length (AL) and differences among the groups were analyzed. The subjects were further divided into a low myopia degree subgroup (LM, -1.50 D ≤ SE ≤ -0.50 D), a moderate myopia degree subgroup (MM, -3.00 D ≤ SE ＜ -1.50 D), and a high myopia degree subgroup (HM, -5.00 D ≤ SE ＜ -3.00 D). A one-way ANOVA and multiple linear regression analysis were used to compare AL elongation and the factors influencing the different groups.

RESULTS

A total of 496 (92 %) subjects completed the study. The mean AL change in the OK lenses, DIMS lenses, and SVS were 0.20±0.18 mm, 0.30±0.22 mm, and 0.38±0.19 mm, respectively (P < 0.001). In the LM subgroup, the OK and DIMS groups showed similar AL changes, but both exhibited slower changes than the SVS group (P = 0.001). In the MM and HM subgroups, the OK lens performed the shortest AL elongation compared with the DIMS lenses and SVS (P < 0.001). Multiple regression analysis showed that the AL change was associated with age (β = -0.038 and P = 0.005), initial AL (β = -0.010 and P = 0.011), initial SE (β = 0.028 and P = 0.007), and interventions using OK lenses (β = -0.172 and P = 0.020) and DIMS lenses (β = -0.089 and P = 0.020).

CONCLUSION

Over a one-year treatment period, OK and DIMS lenses can significantly retard AL elongation compared with SVS. In addition, the OK lenses were more effective than the DIMS lenses in controlling AL in patients with higher degrees of myopia.

Evaluation and comparison of optical coherence tomography angiography (OCTA) parameters in normal and moderate myopic individuals

OBJECTIVE

The objective of this study was to evaluate and compare Optical Coherence Tomography Angiography (OCTA) parameters in patients with moderate myopia and healthy individuals retrospectively.

METHODS

A total of 80 male individuals aged 18-20 years were included in the study with 40 moderate myopic and 40 healthy persons. All participants underwent detailed ocular examination including refraction, intraocular pressure (IOP), visual acuity, biomicroscopy, OCTA measurement and optic biometry measurement. Retinal, retinal nerve fiber layer and choroidal layer thicknesses were evaluated in µm with the help of the software available in the OCTA device.

RESULTS

The mean axial length (24.32 ± 0.53 mm) was statistically significantly higher in the moderate myopic group (24.32 mm) compared to the healthy group (23.33 ± 0.61 mm) (p < 0.001). Spherical equivalent (SE) was found as -3.79 ± 0.91 D in the moderate myopic group and -0.22 ± 0.32 D in the healthy group (p < 0.05). The mean superficial foveal mean density (FovSupMVD) and the mean deep foveal mean density (FovDepMVD) were statistically significantly lower in the moderate myopic group than in the healthy group (both, p < 0.001). The mean retinal temporal thickness (RTt) was statistically significantly lower in the moderate myopic group (p = 0.017). There was a mild negative correlation between axial length and FovSupMVD, FovDepMVD in myopes. In axial length ROC analysis, the cutoff value for moderate myopes was found to be 24.15 mm. Mean superficial foveal mean density (FovSupMVD) and mean deep foveal mean density (FovDepMVD), mean retinal temporal thickness (RTt) were significantly lower in the group above 24.15 mm axial length compared to the group below 24.15 mm axial length (all three, p < 0.001). Foveal avascular zone was significantly higher in the group above 24.15 mm axial length (p = 0.016) CONCLUSION: The results of our study indicate that the mean axial length and spherical equivalent were significantly higher, while retinal temporal thickness, the mean superficial foveal mean density and the mean deep foveal mean density were significantly lower in patients with myopia up to -6.0 D compared to the healthy individuals.

Two-Year Myopia Management Efficacy of Extended Depth of Focus Soft Contact Lenses (MYLO) in Caucasian Children

PURPOSE

To evaluate the progression of myopia as assessed by change in axial length (AL) and spherical equivalent (SE) from baseline in Caucasian children wearing extended depth of focus soft contact lenses (CLs) compared to distance single-vision spectacles.

DESIGN

Prospective non-randomized comparative clinical trial.

METHODS

A total of 90 children (6-13 years of age) with SE ranging from -0.75 to -10.00 diopters (D) were recruited. Of these children, 45 were fitted with CLs (MYLO, mark´ennovy), whereas 45 children wore spectacles. Cycloplegic refraction was measured with an auto-refractometer (Topcon-TRK-2P) and AL with an IOLMaster-700 (Zeiss) at 6-month intervals. Subjective responses after 1 month of CL wear related to vision and comfort were determined using a questionnaire with a scale from 1 (very poor) to 10 (excellent). High-contrast visual acuity (HCVA) and contrast sensitivity (CS) were evaluated at baseline, 12, and 24 months.

RESULTS

After 2 years, mean change in SE/AL in the CL group was -0.62 ± 0.30 D/0.37 ± 0.04 mm and -1.13 ± 0.20 D/0.66 ± 0.03 mm in the spectacles group (P < .001). Cumulative absolute reduction in axial elongation (CARE) was 0.29 ± 0.06 mm. Difference in SE change was -0.50 ± 0.34 D. Although 100% of CL group had an AL increase ≤0.50 mm, all participants increased ≥0.50 mm in the spectacles group. In all, 53% of the CL group and 1% in the spectacles group showed a progression in SE ≤ -0.50D. All questionnaire items showed a mean value ≥9. There was a reduction logMAR HCVA in the CL compared to the spectacles group but it was less than 1 line (P < .001).

CONCLUSIONS

Use of MYLO CLs reduced axial elongation and myopia progression compared to use of distance single-vision spectacles.