Myopia

Clinical and anatomical features of myopia

The purpose of the review is to summarize clinical and anatomically-related aspects of myopia. Recent studies have revealed macular atrophy as myopic maculopathy (MMP) stage-4 was accompanied by a central Bruch´s membrane (BM) defect associated with a subretinal proliferation (as sign of previous macular neovascularization). Patchy atrophies (MMP-stage 3) could be differentiated into those without versus with BM defects/subretinal proliferations. BM defects and subretinal proliferations were associated with each other (OR: 78.3; P < 0.001). Fundus tessellation as MMP-stage-1 correlated with visual acuity reduction, suggesting pathological changes already at MMP stage 1, in addition to a leptochoroid as risk factor. Myopic parapapillary beta zone (potentially caused by an axial elongation-related enlargement of the retinal pigment epithelium [RPE] layer opening; characterized by small or no alpha zone, few or no RPE drusen at its border, normal BM thickness) can be differentiated from glaucomatous parapapillary beta zone (characterized by alpha zone, RPE drusen, and thickened BM). The overlying retinal layers extended into the parapapillary zones, deeper than the superficial layers. Prevalence of non-glaucomatous optic neuropathy increased non-linearly with longer axial length in highly myopic eyes and was a major cause for vision loss in high myopia. In patients aged 85 + years, prevalence of MMP stage 3 or 4 in highly myopic eyes (axial length ≥ 26.5 mm) was about 75 %. Myopia was associated with a lower prevalence of diabetic retinopathy, age-related macular degeneration and angle-closure glaucoma, while high myopia, more than moderate myopia, was associated with higher prevalence and incidence of open-angle glaucoma.

Is there an impending epidemic of myopia in Southeast Asia? An appraisal of the evidence

Predictions on the future prevalence of myopia suggest one of the Global Burden of Disease regions will develop an epidemic like in East Asia and Singapore in Southeast Asia. This paper analyses the available evidence on prevalence of myopia in this region, concluding that the bulk of the evidence suggests that the prevalence of myopia at the end of schooling is still modest, although two papers suggest that in young adults in Thailand and Indonesia, the prevalence of myopia may be approaching levels typical of the epidemic of myopia. It also analyses an indicator of expected years of education at school entry, as well as current educational levels of adults, using data from the calculation of the UN Human Development Index. It then analyses the results obtained by the countries of the Southeast Asian region in the PISA international surveys of student achievement. Neither of these educational indicators suggests an impending epidemic of myopia. There is a need for more data to clarify this uncertainty. It is suggested that future collection of data concentrate on determining the prevalence of myopia in young adults finishing their schooling. Even methodology as simple as determining levels of lowered visual acuity in senior school students should be sufficient to resolve the uncertainty. This group provides a sound basis for the prediction of future levels of myopia in the adult population, and avoids the impact of the high levels of myopia and high myopia associated with cataract development that occur in much of Southeast Asia.

Artificial intelligence in myopia in children: current trends and future directions

PURPOSE OF REVIEW

Myopia is one of the major causes of visual impairment globally, with myopia and its complications thus placing a heavy healthcare and economic burden. With most cases of myopia developing during childhood, interventions to slow myopia progression are most effective when implemented early. To address this public health challenge, artificial intelligence has emerged as a potential solution in childhood myopia management.

RECENT FINDINGS

The bulk of artificial intelligence research in childhood myopia was previously focused on traditional machine learning models for the identification of children at high risk for myopia progression. Recently, there has been a surge of literature with larger datasets, more computational power, and more complex computation models, leveraging artificial intelligence for novel approaches including large-scale myopia screening using big data, multimodal data, and advancing imaging technology for myopia progression, and deep learning models for precision treatment.

SUMMARY

Artificial intelligence holds significant promise in transforming the field of childhood myopia management. Novel artificial intelligence modalities including automated machine learning, large language models, and federated learning could play an important role in the future by delivering precision medicine, improving health literacy, and allowing the preservation of data privacy. However, along with these advancements in technology come practical challenges including regulation and clinical integration.

The association between macronutrients intake and myopia risk: a systematic review and meta-analysis

BACKGROUND

Dietary factors have been suggested as potential risk factors for myopia, but research findings on this relationship are inconclusive. The potential predisposing or protective role of macronutrient (carbohydrate, protein, fat) intake in the development of myopia was systematically reviewed, followed by data synthesis by meta-analysis.

METHODS

A systematic search was conducted in PubMed, Web of Science, Scopus, and Google Scholar up to the end of June 2023 to identify all relevant studies. All observational studies that assessed the relationship between macronutrient intake with myopia, axial length (AL) of eyes and spherical equivalent refractive error (SE) on individuals younger than 18 years old were included.

RESULTS

After removing duplicates and screening studies, four studies were included in the systematic review and meta-analysis. Pooled odds ratios regarding the association between myopia development and nutritional intake were 1.01 (95% CI: 0.94, 1.08), 0.97 (95% CI: 0.86, 1.08), and 0.99 (95% CI: 0.83, 1.18) for carbohydrates, proteins, and fats, respectively, indicating no significant associations. Intake of carbohydrates, proteins, and fats was not significantly associated with either SE or AL.

CONCLUSIONS

Intake of carbohydrates, fats, or proteins did not influence the risk of myopia. The relationship between the intake of other macronutrients and myopia is suggested to be scrutinized in future studies.

REGISTRATION

The systematic review protocol was registered on PROSPERO (registration number: CRD42024541369).

Association between weekend catch-up outdoor duration and prevalence of myopia: evidence from a cross-sectional, multi-center study in China

BACKGROUND

This study aimed at investigating the relationship between the weekend catch-up outdoor duration (WCOD) and prevalence of myopia among students in China.

METHODS

This cross-sectional study recruited participants in 107 schools (six cities, 30 districts) from China from May to June 2021. Demographic characteristics (age, grade, sex, ethnicity, BMI, resident, and parents' myopia), optically habits (bad writing habits, working/studying time per day, continuous working/studying time per day, and screen time per day) and outdoor duration (weekday and weekend) were obtained from questionnaire. WCOD was defined as outdoor time 1 h longer on weekends than on weekdays. Spherical equivalent (SE) of refractive error were measured with non-cycloplegic refraction. Adjusted multivariate logistic regression analysis was performed to evaluate the relationship between WCOD and prevalence of myopia.

RESULTS

Students with myopia had shorter WCOD compared with those without myopia (P < 0.001). Adjusted multivariate logistic regression analyses showed negative associations between WCOD and prevalence of myopia in Chinese students, especially in students with WCOD of 2-3 h (OR = 0.577, P < 0.001) and 3-4 h (OR = 0.571, P = 0.004) when the weekday outdoor duration was 0.5-1 h, as well as students with WCOD of 2-3 h (OR = 0.614, P = 0.003) when the weekday outdoor duration was 1-2 h. Similar results were observed in students with high myopia. Students with high myopia had shorter WCOD compared with those without high myopia (P = 0.001). Negative associations between WCOD and prevalence of high myopia were significant in students with WCOD of 1-2 h when the weekday outdoor duration was < 0.5 h (OR = 0.585, P = 0.007) and 0.5-1 h (OR = 0.537, P = 0.018).

CONCLUSION

Our study, for the first time, reported that a WCOD have a potential to reduce the prevalence of myopia and high myopia in Chinese students.

Prevalence and association of uncorrected refractive error among Chinese adolescents: a cross-sectional study

BACKGROUND

Uncorrected refractive error (URE) is one of the main causes of visual impairments. URE may reduce interaction and learning in the classroom, leading to social isolation, irreversible amblyopia, lack of external knowledge, and restrictions on education and employment opportunities. Our aim was to investigate the prevalence and related factors of URE in adolescents using epidemiological surveys and questionnaire surveys related to lifestyle habits.

METHODS

A cross-sectional school-based study was conducted in Nantong, China, including adolescents 12-19 years of age from 16 schools. URE was defined as presenting visual acuity worse than 6/12 and improving to ≥ 1 lines after correction in either eye. Univariate and multivariate logistic regression analyses were used to investigate specific correlations between URE and related lifestyle parameters. Non-cycloplegic autorefraction was assessed for each adolescent.

RESULTS

A total of 2,910 adolescents were analyzed, of which 50.3% (n = 1,465) were male, and 49.7% (n = 1,445) were female. The mean age was 15.23 ± 1.77 years. The overall prevalence of URE was 23.7%. The total prevalence of REC and eREC was 85.1% and 71.7%, respectively, and both of them showed an increasing trend with age (Ptrend = 0.018 and Ptrend = 0.019, respectively). A higher prevalence of URE was related to myopia, anisometropia, and increased daily use of electronic products. Timely visual examination by medical institutions, more extracurricular homework, and older age were protective factors for URE. Among the 689 adolescents with URE, 362 (52.5%) did not receive any refractive correction, and 327 (47.5%) used corrected glasses.

CONCLUSION

URE was highly prevalent among adolescents in China. Myopia was the most important risk factor for URE. The impact of anisometropia and increased daily use of electronic devices on URE was significant. Timely visual examinations by medical institutions served as an effective protective factor against URE. Further research on adjusting intervention strategies is therefore needed to eliminate preventable visual impairments.

Effects of atropine on choroidal thickness in myopic children: a meta-analysis

Background

Atropine is an effective medicine for myopia prevention and control. This meta-analysis was conducted to investigate the effects of atropine on choroidal thickness (ChT) in children with myopia.

Methods

Between its inception and 1 June 2023, Medline, Embase, and Web of Science were all searched, and only English literature was included. The choroidal thickness was the primary study outcome. Axial length, standardized equivalent refraction were examined as secondary outcomes. STATA 12.0 was used for data extraction and analysis.

Results

A total of 307 eyes were involved in this study to evaluate the effect of atropine on ChT, axial length (AL) and standardized equivalent refraction (SER) in myopic children. Choroidal thickening was significantly higher in the atropine group than in the control group at 1 month (WMD, 6.87 mm, 95% CI, 0.04 to 13.10, P = 0.049), whereas it was significantly higher in the atropine group than in the control group at months 6 (WMD, 10.37 mm, 95% CI, -3.21 to 23.95, P = 0.135), 12 (WMD, 15.10 mm, 95% CI, -5.08 to 35.27, P = 0.143) and at final follow-up (WMD, 11.52 mm, 95% CI, -3.26 to 26.31, P = 0.127), the differences were not statistically significant. At months 1 (WMD, -0.03 mm, 95% CI, -0.04 to -0.01, P = 0.003), 6 (WMD, -0.07 mm, 95% CI, -0.01 to -0.03, P = 0.000), 12 (WMD, -0.13mm, 95% CI, -0.15 to -0.11, P = 0.843), and at final follow-up (WMD, -0.08 mm, 95% CI, -0.16 to -0.01, P = 0.127), atropine treatment was able to delay the axial elongation. At 1-month follow-up, there was no significant difference in the effect of atropine on SER in myopic children compared with the control group (WMD, 0.01D, 95% CI, -0.07 to 26.31, P = 0.127), whereas it was able to control the progression of refractive status at final follow-up (WMD, 11.52 mm, 95% CI, -3.26 to 26.31, P = 0.127).

Conclusion

Limited evidence suggests that 0.01% atropine causes choroidal thickening in myopic children at 1 month of treatment. In the short term, choroidal thickness may be a predictor of the effectiveness of atropine in controlling myopia in children. 0.01% atropine is effective in controlling myopic progression in terms of SER and AL.

Systematic Review Registration

http://www.crd.york.ac.uk/prospero, identifier, CRD42022381195.

Association between axial length and uveitis

PURPOSE

Multiple studies have examined the association between myopia and various ocular diseases, but there is no clinical report of the relationship between myopia and uveitis. This study aimed to elucidate the relationship between myopia and uveitis by comparing axial lengths (AL) of uveitis patients with control individuals.

METHODS

This study included 1052 eyes (663 patients; 288 males, 375 females; median age 56.0 years) with uveitis referred to Tokyo Medical University Hospital. Controls were 738 eyes with cataract but no other ocular diseases. AL was measured by IOLMaster or conventional A-mode ultrasound system. Uveitis eyes were grouped into various types of non-infectious uveitis, infectious uveitis, and unidentified uveitis. Median AL of each uveitis group was compared with control group using Mann-Whitney U-test, and also compared with adjustment for age and sex using multiple regression analysis. Binary logistic analysis was performed to examine whether AL plays a role in the risk of developing uveitis.

RESULTS

Of 1052 eyes, 808 eyes (76.8%) were diagnosed with non-infectious uveitis [sarcoidosis (176 eyes, 16.7%), Vogt-Koyanagi-Harada disease (122 eyes, 11.6%), Behçet's disease (130 eyes, 12.4%), and others (380 eyes, 36.1%)], 146 eyes (13.9%) with infectious uveitis, and 98 eyes (9.3%) with unidentified uveitis. Median AL in all uveitis eyes was significantly shorter than in control eyes (23.73 vs 24.31 mm, p < 0.001 unadjusted), and AL remained significantly shorter in uveitis than in control after age- and sex-adjustment (p < 0.001). Median AL was significantly shorter in non-infectious uveitis (23.72 mm) and in infectious uveitis (23.99 mm) compared to controls (p < 0.001 and < 0.05, respectively), and was significantly shorter in non-infectious uveitis than in infectious uveitis (p < 0.05). Each millimeter decrease in AL was associated with 1.266-fold increase in unadjusted risk [odds ratio (OR), 1.266; 95% confidence interval (CI), 1.196-1.341; p < 0.001) and 1.446-fold in age- and sex-adjusted risk (OR, 1.446; 95% CI, 1.349-1.549; p < 0.001) of developing uveitis.

CONCLUSION

Median AL of uveitis eyes with infectious or non-infectious etiologies was significantly shorter than that in control eyes, suggesting an increased risk of developing uveitis in eyes with shorter AL. This feature should be considered when exploring new pathogenetic mechanisms of uveitis.

KEY MESSAGES

What is known Shorter axial length may be associated with the pathogenesis of central serous chorioretinopathy and increased risk of early age-related macular degeneration. What is new Here we assessed the relationship between myopia and uveitis by comparing axial lengths of uveitis patients. Median axial length in all uveitis eyes was significantly shorter than in control eyes, and axial length remained significantly shorter in uveitis than in control after age- and sex-adjustment. Each millimeter decrease in axial length was associated with 1.266-fold increase in unadjusted risk and 1.446-fold in age- and sex-adjusted risk of developing uveitis.

Refractive error and ocular alignment in school-aged children from low-income areas of São Paulo, Brazil

BACKGROUND

Uncorrected refractive errors and amblyopia are reported as the two main causes of childhood visual impairment and blindness worldwide. Our purpose was to evaluate refractive status, ocular alignment and effective refractive error coverage (eREC) of school-aged children from low-income areas of Sao Paulo city, Brazil.

METHODS

Data from the "Ver na Escola" Project were used for the current study. Children enrolled in the selected schools had an ophthalmic exam including eye alignment assessed by cover test, automatized and subjective dynamic and static refraction. The associations of demographic variables with occurrence and magnitude of refractive errors and eREC were investigated by multiple logistic regressions and multilevel mixed effect models.

RESULTS

A total of 17,973 children (51.12% females) with mean ± sd age 8.24 ± 3.54 years old examined from July 2018 to July 2019, were included in the study. Most of the participants (73%) showed orthoposition of the visual axis for both distance and near. Heterophoria was found in about 25% of participants (N = 4,498), with 71.7% of them (N= 3,222) classified as exophoria. Less than 2% (N = 232) showed strabismus, most of them (N = 160) esotropia. Overall, 1,370 (7.70%) of participants had myopia and 577 (3.24%) had hyperopia. Age was found to be significantly associated with increasing static subjective refraction spherical equivalent (Coefficient: -0.18; 95% Confidence Interval (CI): -0.21 to -0.16; p < 0.001). Female sex (Odds Ratio (OR) = 1.13; 95%CI: 1.01-1.27; p = 0.027) and older age (OR = 1.17; 95%CI: 1.16-1.19; p < 0,001) were significantly associated with myopia diagnosis. Older age decreased the odds of hyperopia (OR = 0.95; 95%CI: 0.93-0.98; p < 0.001). The overall effective refractive coverage was 51.76% and was significantly associated with age group, ranging from 32.25% in children aged 3 to 7 years to 61.35% in children aged 8 to 12 years.

CONCLUSIONS

Most children have shown eye alignment for both distance and near assessments and no refractive error. Myopia was observed in 7.70% of the population and it was associated with older age and female sex. Hyperopia was observed in 3.24% and was associated with younger age. The overall eREC was 51.76%, significantly associated with age.

A higher shadow ratio of the living environment on the remote sensing digital image is possibly protective for adolescent myopia

This study aims to assess how the construction patterns within residential communities influence the adolescent myopia using general survey. In a private high school from a megacity in mid-west China, a questionnaire gathered data on the 10th-grade students' level of myopia, home address, and some potential confounding factors. Additionally, satellite digital images were utilized to calculate the proportion of shadow area (PSA) and the proportion of greenness area (PGA) within a 500 m×500 m area centered on each student's home address. Correlations between myopia levels and PSA, along with other variables, were analyzed. The prevalence of mild, moderate, and high myopia were 39.2%, 32.5%, and 8.3%, respectively. A negative correlation was observed between myopia levels and PSA, albeit marginally significant (r=-0.189*, P = 0.05). Upon dividing the sample into higher and lower PSA groups using a cut-off point of 20%, a significant difference in myopia levels was evident (χ2 = 8.361, P = 0.038), while other confounding factors remained comparable. In conclusion, high-rise apartment constructions, which often cast more shadows on digital satellite maps, may not exacerbate myopia progression. Instead, they could potentially serve as a protective factor against adolescent myopia in densely populated megacities, as they allow for more ground space allocation.

Lifestyle and risk of developing myopia in school children in Chongqing, China

Introduction

Myopia has emerged as a leading global reason for poor vision in children and adolescents. this study aims to investigate the influence of lifestyles on myopia in schoolchildren in Chongqing, China.

Methods

This cross-sectional study was conducted on primary and junior high school graduates in Chongqing City, China. Students who came to the assigned hospital for the physical examination of their upgrade school enrollment were recruited. In addition to regular examination and eyeusing questionnaire, visual acuity and non-cycloplegic autorefraction were measured.

Results

Of all 1806 eligible students, 1,623 students (89.87%) were included in the analysis. The prevalence of myopia in elementary and junior middle school graduates was 73.1 and 81.8%, respectively. According to the multivariate logistic regression analysis, 1 h more homework (OR = 1.272, p = 0.032), attending out-school courses (OR = 1.973, p = 0.006), frequently checking of eyes (OR = 1.337, p = 0.015) and using eye-protecting lamp (OR = 2.528, p < 0.001) were more likely to be associated with myopia (p < 0.05). While 1 h more outdoor activity in weekday (OR = 0.811, p = 0.033) and weekend (OR = 0.796, p = 0.034) were less likely to have myopia.

Conclusion

The current prevalence of myopia among elementary and junior high school students in Chongqing is high. Academic pressures, bad habits of using eyes, and limited time for outdoor activity mainly contribute to the epidemic of myopia. Various policies in and out of schools related to reducing academic pressures, increasing outdoor activities, and improving eye habits may help control the prevalence of myopia in teenagers.

Key role for inflammation-related signaling in the pathogenesis of myopia based on evidence from proteomics analysis

The mechanisms underlying myopia pathogenesis are not well understood. Using publicly-available human and animal datasets, we expound on the roles of known, implicated proteins, and new myopia-related signaling pathways were hypothesized. Proteins identified from human serum or ocular fluids, and from ocular tissues in myopic animal models, were uploaded and analyzed with the QIAGEN Ingenuity Pathway Analysis (IPA) software (March 2023). With each IPA database update, more potentially-relevant proteins and signaling pathways previously unavailable during data acquisition are added, allowing extraction of novel conclusions from existing data. Canonical pathway analysis was used to analyze these data and calculate an IPA activation z-score-which indicates not only whether an association is significant, but also whether the pathway is likely activated or inhibited. Cellular immune response and cytokine signaling were frequently found to be affected in both human and animal myopia studies. Analysis of two publicly-available proteomic datasets highlighted a potential role of the innate immune system and inflammation in myopia development, detailing specific signaling pathways involved such as Granzyme A (GzmA) and S100 family signaling in the retina, and activation of myofibroblast trans-differentiation in the sclera. This perspective in myopia research may facilitate development of more effective and targeted therapeutic agents.

Regional Summed Corneal Refractive Power Changes in Myopic Orthokeratology and Their Relationships With Axial Elongation

PURPOSE

To determine the relationship between regional summed corneal refractive power changes (CRPCs) in myopic orthokeratology and axial elongation.

DESIGN

This retrospective study included 70 eyes of 70 patients aged 8 years to 13 years who underwent orthokeratology lens (OK lens) treatment, and all patients underwent regular follow-ups at 1 week, 1 month, 6 months, and 12 months at Zhongshan Ophthalmic Center between January 2019 and May 2021.

METHODS

Axial length (AL) was measured at baseline and 12 months by an IOLmaster 5.0. Refractive error power was measured using cycloplegia. Regional summed CRPCs were calculated by MATLAB software using difference tangential power maps at the sixth month acquired by corneal topography measurements (Medmont E300 Corneal Topographer; Medmont Pty, Victoria, Australia) and defined as changes in corneal refractive power at the sixth month from baseline. The regional summed CRPCs were then subdivided into 4-mm diameter circles, 4- to 5-mm diameter chords, and 5- to 6-mm diameter chords according to the distance from the central of the pupil and into negative, positive, and total according to the values. Pearson correlation, multiple linear regression analysis, and stepwise multiple linear regression analysis were performed to analyze the relationships among these parameters.

RESULTS

Axial elongation had a negative relationship with positive regional summed corneal refractive power in the central 4-mm diameter circle and age (r=-0.282, P =0.018; r=-0.473, P <0.001, respectively) and a positive relationship with negative regional summed corneal refractive power in the 5- to 6-mm diameter chord (r=0.361, P =0.002). Stepwise multiple linear regression analysis identified age (standardized β =-0.434, P <0.001) and negative regional summed corneal refractive power in the 5- to 6-mm diameter chord (standardized β =0.305, P =0.004) as factors influencing AL elongation.

CONCLUSION

Negative regional summed corneal refractive power in a 5- to 6-mm diameter chord after OK lens treatment may be an important index for evaluating the control effects of axial elongation.

A First-Passage Model of Intravitreal Drug Delivery and Residence Time-Influence of Ocular Geometry, Individual Variability, and Injection Location

Purpose

Standard of care for various retinal diseases involves recurrent intravitreal injections. This motivates mathematical modeling efforts to identify influential factors for ocular drug residence time, aiming to minimize administration frequency. We sought to describe the vitreal diffusion of therapeutics in nonclinical species frequently used during drug development assessments. In human eyes, we investigated the impact of variability in vitreous cavity size and eccentricity, and in injection location, on drug disposition.

Methods

Using a first-passage time approach, we modeled the transport-controlled distribution of two standard therapeutic protein formats (Fab and IgG) and elimination through anterior and posterior pathways. Anatomical three-dimensional geometries of mouse, rat, rabbit, cynomolgus monkey, and human eyes were constructed using ocular images and biometry datasets. A scaling relationship was derived for comparison with experimental ocular half-lives.

Results

Model simulations revealed a dependence of residence time on ocular size and injection location. Delivery to the posterior vitreous resulted in increased vitreal half-life and retinal permeation. Interindividual variability in human eyes had a significant influence on residence time (half-life range of 5-7 days), showing a strong correlation to axial length and vitreal volume. Anterior exit was the predominant route of drug elimination. Contribution of the posterior pathway displayed a 3% difference between protein formats but varied between species (10%-30%).

Conclusions

The modeling results suggest that experimental variability in ocular half-life is partially attributed to anatomical differences and injection site location. Simulations further suggest a potential role of the posterior pathway permeability in determining species differences in ocular pharmacokinetics.

Intraocular amphiregulin and axial elongation in non-human adolescent primates

The purpose of the experimental interventional study was to examine the influence of intraocularly applied amphiregulin, a member of the epidermal growth factor (EGF) family, on axial length in young non-human primates. It included three non-human primates (Macaca mulatta), aged 4-6 years. The left eyes received three intravitreal injections of amphiregulin (400ng/50 μl) in intervals of 4 weeks, while the right eyes received three intravitreal injections of phosphate buffered solution (50 μl) at the same time points. Ocular biometry was performed in weekly intervals. At baseline, the left eyes (study eyes) were shorter than the right (control) eyes (20.69 ± 0.21 mm versus 20.79 ± 0.24 mm; P < 0.001), with an inter-eye axial length (AL) difference (left minus right eye) of -0.10 ± 0.23 mm. Inter-eye AL difference increased (P < 0.001) to 0.15 ± 0.18 mm at study end, at 12 weeks after baseline. Axial elongation during the study was higher (P < 0.001) in the left eyes (20.69 ± 0.21 mm to 21.05 ± 0.29 mm or 0.36 ± 0.30 mm) than in the right eyes (20.79 ± 0.24 mm to 20.90 ± 0.31 mm or 0.11 ± 0.17 mm). In a parallel manner, inter-eye difference in vitreous cavity depth combined with lens thickness (left eye minus right eye) increased from -0.04 ± 0.17 mm at baseline to -0.02 ± 0.21 mm (P = 0.02), 0.04 ± 0.10 mm (P = 0.002), and to 0.42 ± 0.67 mm (P < 0.001) at 5, 6, and 12 weeks after baseline, respectively. The results suggest that intravitreally applied amphiregulin as EGF family member led to an increase in axial length in adolescent non-human primates. It supports the hypothesis of amphiregulin as EGF family member being involved in the process of axial elongation.

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.

Genome-Wide Association Analysis Identifies LILRB2 Gene for Pathological Myopia

Pathological myopia (PM) is one of the leading causes of blindness, especially in Asia. To identify the genetic risk factors of PM, a two-stage genome-wide association study (GWAS) and replication analysis in East Asian populations is conducted. The analysis identified LILRB2 in 19q13.42 as a new candidate locus for PM. The increased protein expression of LILRB2/Pirb (mouse orthologous protein) in PM patients and myopia mouse models is validated. It is further revealed that the increase in LILRB2/Pirb promoted fatty acid synthesis and lipid accumulation, leading to the destruction of choroidal function and the development of PM. This study revealed the association between LILRB2 and PM, uncovering the molecular mechanism of lipid metabolism disorders leading to the pathogenesis of PM due to LILRB2 upregulation.

Lifelong Changes in the Choroidal Thickness, Refractive Status, and Ocular Dimensions in C57BL/6J Mouse

Purpose

To investigate the changes in choroidal thickness (ChT), refractive status, and ocular dimensions in the mouse eye in vivo using updated techniques and instrumentation.

Methods

High-resolution swept-source optical coherence tomography (SS-OCT), eccentric infrared photoretinoscopy, and custom real-time optical coherence tomography were used to analyze choroidal changes, refractive changes and ocular growth in C57BL/6J mice from postnatal day (P) 21 to month 22.

Results

The ChT gradually increased with age, with the thickest region in the para-optic nerve head and thinning outward, and the temporal ChT was globally thicker than the nasal ChT. Retinal thickness remained stable until 4 months and subsequently decreased. The average spherical equivalent refraction error was -4.81 ± 2.71 diopters (D) at P21, which developed into emmetropia by P32, reached a hyperopic peak (+5.75 ± 1.38 D) at P82 and returned to +0.66 ± 1.86 D at 22 months. Central corneal thickness, anterior chamber depth, lens thickness, and axial length (AL) increased continuously before 4 months, but subsequently exhibited subtle changes. Vitreous chamber depth decreased with lens growth. ChT was correlated significantly with the ocular parameters (except for retinal thickness) before the age of 4 months, but these correlations diminished after 4 months. Furthermore, for mice younger than 4 months, the difference in the ChT, especially temporal ChT, between the two eyes contributed most to that of axial length and spherical equivalent refraction error.

Conclusions

Four months could be a watershed age in the growth of mouse eyes. Large-span temporal recordings of refraction, ocular dimensions, and choroidal changes provided references for the study of the physiological and pathological mechanisms responsible for myopia.

Study on the relationship between adolescent myopia and gut microbiota via 16S rRNA sequencing

Myopia has become a global public health problem, with a high incidence among adolescents. In recent years, the correlation between gut microbiota and various diseases has become a research hotspot. This paper analyzes the relationship between myopia and gut microbiota in adolescents based on 16S rRNA sequencing, opening up a new avenue for the prevention and control of myopia. 80 adolescents aged 6-15 years were included; fecal samples were collected to compare their diversity and species differences. There was no significant difference in α diversity when considering richness and evenness at the same time (P > 0.05). While the group difference in β diversity reached a significant level (R2 = 0.022, P < 0.05). The absolute quantification and relative abundance of phylum level Firmicutes and Actinobacteriota are different; among the top 30 genera, myopic group only one genus decreased in absolute quantification, while 13 genera decreased in relative quantification; so LEfSe analysis was performed, and the result showed that microbial community composition changed under Linear discriminant analysis (LDA) score, the top ten changes are shown in the figure; the Wilcoxon Rank sum test also found some significant changes in the absolute abundance of differential microbiota among different groups, at the phylum level, one bacterial phylum decreased and three bacterial phyla increased; at the genus level, 2 bacteria genera decreased and 29 bacteria genera increased. Functional pathways prediction found many myopic-related pathways were functionally enhanced in myopic patients (P < 0.05). Multivariate logistic regression analysis results showed that the area under the curve (AUC) of myopic patients predicted was close to or equal to 1. In conclusion, adolescent myopia is closely related to the gut microbiota, and the characteristic gut microbiota can distinguish myopia from healthy controls to a large extent. Therefore, it can be considered to regulate these characteristic gut microbiota to prevent and control myopia.

Retinal curvature in Chinese children with myopia measured by ultra-widefield swept-source optical coherence tomography

AIMS

To quantitatively measure retinal curvature (RC) in children with myopia and explore its association with refractive status.

METHODS

This cross-sectional study included participants aged 5-18 years who underwent comprehensive ocular examinations, including cycloplegic refraction and macula 24×20 mm optical coherence tomography (OCT) scans. RC was derived from OCT data using a three-dimensional reconstruction system. Mean RC was assessed in concentric circles (RC I-VI) with diameters of 1, 3, 6, 9, 12 and 15 mm around the fovea, as well as in four orientations (RC S/I/N/T).

RESULTS

A total of 443 eyes were included in the analysis. The values from RC I to RC VI were 0.51±0.19, 0.53±0.19, 0.62±0.19, 0.76±0.23, 0.86±0.23 and 0.81±0.18 10-2mm-2, respectively. RC I exhibited the smallest curvature, while RC V displayed the highest (p<0.001). High myopia (HM) group demonstrated larger RC I and smaller RC III/IV/V/VI compared with low myopia (LM) group (p<0.01). Significant differences among RC S/I/N/T were observed in HM group (pairwise comparison, p<0.001), but not in LM group. Multiple regression analysis revealed that age, sex, corneal curvature radius and subfoveal choroidal thickness (SFCT) were associated factors with foveal RC, while age, SFCT and axial length (AL) were associated factors of peripheral RC.

CONCLUSION

RC can quantitatively characterise retinal shape and the morphological changes induced by myopia. Myopia progression results in a bulging macular retina accompanied by a flattening peripheral retina in children, and also increases the irregularity among the four quadrants. Age, AL and SFCT are associated factors of RC.

Distribution and Determinants of Anterior Chamber Angle and Anterior Chamber Volume in Young Chinese Adults

PURPOSE

Current study aimed to understand the distribution and determinants of anterior chamber angle (ACA) and anterior chamber volume (ACV) in Chinese young adults, which can help fill current data gaps and aid in early detection and intervention for high-risk population of primary angle closure glaucoma.

METHODS

This cross-sectional study utilized data from 2014 participants who completed questionnaire and eye examination in September 2021. ACV and ACA were measured using a Pentacam tomographer. Spherical equivalent (SE) was evaluated by autorefractor without cycloplegia. Central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were evaluated using Corvis-ST. Axial length (AL), corneal radius (CR), anterior chamber depth (ACD), and white to white were assessed using the IOL Master.

RESULTS

A total of 1635 students were included in the analysis. The mean ACV and AVA were 194.74 ± 32.30 μL and 38.81 ± 4.84°, respectively. Males have a larger ACV and wider ACA than females. ACV was positively correlated with ACA (r = 0.24, p < 0.001), and the correlation was stronger for non-myopic students than for myopic students. Multivariable linear regression model showed that AL (β = 2.41), CR (β = -4.12), CCT (β = -0.11), ACD (β = 97.93), and bIOP (β = 0.40) were associated with ACV, and CCT (β = -0.01), CR (β = 0.38), and ACD (β = 7.41) were associated with ACA (all p < 0.05). Random forest model indicated that ACD was the most critical predictor of both ACV and ACA.

CONCLUSIONS

This study reported the distribution and determinants of ACA and ACV. Deeper ACD was associated with larger ACV and wider ACA.

Effect of virtual reality-based visual training for myopia control in children: a randomized controlled trial

BACKGROUND

To assess the efficacy and safety of virtual reality-based visual training (VRVT) in myopia control among children.

METHODS

The randomized, parallel-group, single-blind clinical trial conducted at the Department of Ophthalmology of Shanghai Tenth People's Hospital enrolled 65 low-myopic children (aged 8 to 13 years) with cycloplegic spherical equivalent (SE) between - 0.50 and - 3.00 diopters (D), astigmatism less than - 1.00 D, anisometropia less than 1.50D, and best corrected visual acuity (BCVA) more than 0.0 logarithm (LogMAR) of the minimum angle of resolution. The participants were enrolled in December 2020, and the follow-up of this study concluded on August 2021. Children were assigned randomly to the intervention group (VRVT plus single-vision spectacle [SVS]) and the control group (only SVS without receiving VRVT). The intervention group was administered for 20 min per day with VRVT under parental supervision at home. The primary outcome was changes in axial length (AL) at 3 months. Macular choroidal thickness (mCT) was regarded as a key secondary outcome.

RESULTS

Among 65 participants (mean age: 10.8 years, 52.3% male), 60 children (92.3%) who completed the 3-month intervention and 6-month follow-up were included in the analysis (30 in the intervention group and 30 in the control group). The changes of AL were 0.063 ± 0.060 mm (95% confidence interval [CI], 0.074 to 0.119 mm) in the intervention group and 0.129 ± 0.060 mm (95% CI, 0.107 to 0.152 mm) and in the control group at 3 months (t = - 2.135, P = 0.037), and the mean difference between the two groups was 0.066 mm. The change of mCT were 22.633 ± 36.171 μm (95% CI, 9.127 to 36.140 μm) in the intervention group and - 3.000 ± 31.056 μm (95% CI, - 14.597 to 8.597 μm) in the control group at 3 months (t = 2.945, P = 0.005). VR vertigo was the most common adverse event which was occurred in two children (2/30, 6.67%) in the intervention group.

CONCLUSIONS

VRVT is a promising method for myopia control in children with good user acceptability. Among children aged 8 to 13 years with low-myopia, nightly use of VRVT resulted in slowing myopia progression.

TRIAL REGISTRATION

This protocol was registered with ClinicalTrials.gov (NCT06250920), retrospectively registered on 01 February 2024.

Prevalence and risk factors for refractive error in older adults in eight ethnicities in China: The China national health survey

Purpose

This study aimed to investigate the prevalence of refractive error (RE) and risk factors for myopia among older adults in the Han and various minority ethnic groups across seven provinces in China.

Methods

This cross-sectional study forms a part of the ophthalmic dataset of the China National Health Survey (CNHS). Face-to-face interviews and ophthalmic examinations were conducted in seven provinces located in western and northern China. The age- and sex-adjusted prevalence of RE among Han and seven other ethnic groups aged 50-80 years were compared. A mixed-effects model was used to identify the risk factors associated with RE.

Results

A total of 12,902 participants, including 8800 Han and 4102 from ethnic minorities, were included in the study. The age- and sex-adjusted prevalence of myopia, high myopia, hyperopia, and astigmatism ranged from 15.3 % (Manchu) to 22.9 % (Han), 0.2 % (Yugur) to 2.8 % (Han), 21.6 % (Tibetan) to 48.9 % (Uyghur), and 38.7 % (Yi) to 57.5 % (Manchu) across different ethnicities, respectively. Compared to the Han population, the Mongolian (odds ratios (OR) 0.62, 95 % confidence interval (CI) 0.46-0.84, p = 0.002), Tibetan (OR 0.66, 95 % CI 0.52-0.85, p = 0.001), Uyghur (OR 0.63, 95 % CI 0.49-0.80, p < 0.001), Yi (OR 0.65, 95 % CI 0.46-0.92, p = 0.014), and Yugur (OR 0.65, 95 % CI 0.50-0.85, p = 0.001) ethnicities were less likely to have myopia. There was no significant difference in the prevalence of myopia between the Manchu, Korean, and Han ethnic groups. Factors associated with a lower prevalence of myopia included rural residence (p < 0.001), a body mass index (BMI) > 18.5 kg/m2 (all p < 0.001), residence in higher latitude areas (p = 0.020), and a history of smoking (p = 0.002 in the past smoking group, p = 0.031 in the current smoking group). The Mongolian (p = 0.006) and Yugur (p = 0.007) populations, participants living in rural areas (p = 0.012), and those with a BMI >24 kg/m2 (p = 0.038 in the >24.0 ≤ 27.0 kg/m2 group or p = 0.041 in the >27.0 kg/m2 group) were less likely to have high myopia. Factors associated with a higher prevalence of hyperopia included older age (all p < 0.001), rural residence (p = 0.039), higher latitude areas (p = 0.031), smoking history (p = 0.040), and Mongolian (p = 0.001), Uyghur (p < 0.001), Yi (p < 0.001), and Yugur (p = 0.002) ethnicities. Conversely, the Manchu population (p = 0.004) and individuals with higher education levels than illiteracy (p = 0.024 or p < 0.001) were less likely to have hyperopia.

Conclusions

Myopia affected more than one-fifth of the older adults in the Han population in this survey. Significant differences in the prevalence of RE were observed between minority ethnicities and Han individuals, except for the Manchu and Korean groups.

Loss of ON-Pathway Function in Mice Lacking Lrit3 Decreases Recovery From Lens-Induced Myopia

Purpose

To determine whether the Lrit3-/- mouse model of complete congenital stationary night blindness with an ON-pathway defect harbors myopic features and whether the genetic defect influences the recovery from lens-induced myopia.

Methods

Retinal levels of dopamine (DA) and 3,4 dihydroxyphenylacetic acid (DOPAC) from adult isolated Lrit3-/- retinas were quantified using ultra performance liquid chromatography after light adaptation. Natural refractive development of Lrit3-/- mice was measured from three weeks to nine weeks of age using an infrared photorefractometer. Susceptibility to myopia induction was assessed using a lens-induced myopia protocol with -25 D lenses placed in front of the right eye of the animals for three weeks; the mean interocular shift was measured with an infrared photorefractometer after two and three weeks of goggling and after one and two weeks after removal of goggles.

Results

Compared to wild-type littermates (Lrit3+/+), both DA and DOPAC were drastically reduced in Lrit3-/- retinas. Natural refractive development was normal but Lrit3-/- mice showed a higher myopic shift and a lower ability to recover from induced myopia.

Conclusions

Our data consolidate the link between ON pathway defect altered dopaminergic signaling and myopia. We document for the first time the role of ON pathway on the recovery from myopia induction.

Lens Power and Associated Factors in Nonhuman Primate Subjects: A Cross-sectional Study

Purpose

We aimed to examine the normative profile of crystalline lens power (LP) and its associations with ocular biometric parameters including age, axial length (AL), spherical equivalent refraction (SE), corneal radius (CR), lens thickness, anterior chamber depth, and AL/CR ratio among a cynomolgus monkey colony.

Methods

This population-based cross-sectional Non-human Primate Eye Study recruited middle-aged subjects in South China. All included macaques underwent a detailed ophthalmic examination. LP was calculated using the modified Bennett's formula, with biometry data from an autorefractometer and A-scan. SPSS version 25.0 was used for statistical analysis.

Results

A total of 301 macaques with an average age of 18.75 ± 2.95 years were collected in this study. The mean LP was 25.40 ± 2.96 D. Greater LP was independently associated with younger age, longer AL, and lower SE (P = 0.028, P = 0.025, and P = 0.034, respectively). LP showed a positive correlation with age, SE, CR, AL, lens thickness, and anterior chamber depth, whereas no correlation was observed between LP and AL/CR ratio.

Conclusions

Our results suggested the LP distribution in the nonhuman primate colony and indicated that AL and SE strongly influenced the rate of LP. Therefore, this study contributed to a deeper understanding of the relative significance of the LP on the optics of the crystalline lens study.

Efficacy of orthokeratology lens with the modified small treatment zone on myopia progression and visual quality: a randomized clinical trial

BACKGROUND

To evaluate the long-term effectiveness of orthokeratology (ortho-K) lenses with small treatment zone (STZ) or conventional treatment zone (CTZ) in controlling axial elongation in children with myopia as well as the impact on visual quality. We also sought to determine the effect of retinal visual signal quality on axial elongation.

METHODS

This is a prospective randomized controlled study. A total of 140 participants (age ranging from 8 to 12 years) were randomly assigned to wear either STZ or CTZ ortho-K lenses. STZ ortho-K lenses design was achieved by changing the depth of reverse zone and the sagitta height of the optical zone. Using the IOL-Master 500, axial length (AL) was measured at baseline and after 6, 12 and 18 months of ortho-K treatment. Spherical aberration (SA) and corneal topographic parameters were obtained by the Pentacam anterior segment analyzer at baseline and the 1-month follow-up visit, and optical qualities were assessed by optical quality analysis system-II (OQAS-II) at baseline and after 1 month of lens wearing. Optical quality parameters mainly included the modulation transfer function (MTF) cutoff, Strehl ratio (SR), objective scattering index (OSI), and predicted visual acuity (PVA).

RESULTS

A total of 131 participants completed the study, including 68 in the STZ group and 63 in the CTZ group. The STZ group had significantly reduced AL elongation compared to the CTZ group after treatment (12 months: 0.07 ± 0.11 mm vs. 0.14 ± 0.12 mm, P = 0.002; 18 months: 0.17 ± 0.15 mm vs. 0.26 ± 0.16 mm, P = 0.002). The topography in the STZ group showed a smaller treatment zone (TZ) diameter (2.50 ± 0.23 mm vs. 2.77 ± 0.18 mm, P < 0.001), a wider defocus ring width (2.45 ± 0.28 mm vs. 2.30 ± 0.30 mm, P = 0.006), and larger values of total amount of defocus (119.38 ± 63.71 D·mm2 vs. 91.40 ± 40.83 D·mm2, P = 0.003) and total SA (0.37 ± 0.25 μm vs. 0.25 ± 0.29 μm, P = 0.015), compared with the CTZ group. Objective visual quality decreased in both groups (P < 0.001). This was evidenced by a greater decrease in MTF cutoff (- 14.24 ± 10.48 vs. - 10.74 ± 9.46, P = 0.047) and SR values (- 0.09 ± 0.07 vs. - 0.06 ± 0.07, P = 0.026), and an increase in OSI value (0.84 ± 0.72 vs. 0.58 ± 0.53, P = 0.019). PVA9% decreased significantly in the STZ group but not the CTZ group. A statistically significant negative correlation was found between the changes in total SA and MTF cutoff values (r =  - 0.202, P = 0.025). AL changes were associated with sex, change of MTF cutoff value, increment of total SA and TZ area.

CONCLUSIONS

Compared with CTZ ortho-K lenses, STZ ortho-K lenses significantly inhibited axial elongation in children with myopia while moderately reducing their objective visual quality. Axial elongation was affected by retinal visual quality, and it may be a possible mechanism for ortho-K slowing myopia progression. Trial registration This trial is registered at Chinese Clinical Trial Registry on November 5, 2019 with trial registration number: ChiCTR1900027218. https://www.chictr.org.cn/showproj.html?proj=45380.

Causal relationships between inflammatory cytokines and myopia: an analysis of genetic and observational studies

Objective

This study aims to explore the causal relationship between inflammatory markers and myopia through the use of bidirectional Mendelian randomization (MR) and myopia animal models.

Methods

The authors utilized data from a comprehensive and publicly accessible genome-wide association study (GWAS) for our analysis, which includes 460 536 European ancestry control subjects and 37 362 myopia patients. Utilizing a two-sample Mendelian randomization analysis framework, 27 inflammatory markers were investigated as exposure variables with myopia serving as the outcome variable. Nine MR analysis techniques were employed, with inverse-variance weighting (IVW) as the principal MR analysis method. Heterogeneity was assessed using Cochrane's Q test. The identification of single-nucleotide polymorphisms (SNPs) and outliers linked to myopia was achieved via MR-PRESSO. The expression of interleukin-2 (IL-2) in the vitreous of guinea pigs subjected to experimentally induced form-deprivation myopia (FDM) was examined.

Results

Elevated concentrations of IL-2 and IL-2ra were found to be associated [IVW estimate odds ratio (OR): 1.003, 95% CI: 1.001-1.005, P=0.001] and strongly associated (IVW estimate OR: 1.002, 95% CI: 1.000-1.003, P=0.049) with an increased risk of myopia, respectively. Conversely, lower levels of C-reactive protein (CRP) (IVW estimate OR: 0.996, 95% CI: 0.994-0.999, P=0.002) and tumour necrosis factor alpha (IVW estimate OR: 0.995, 95% CI: 0.994-0.996, P<0.001) were robustly linked to a heightened risk of myopia. IL-2 expression was notably upregulated in the vitreous of guinea pigs with experimentally induced FDM.

Conclusions

Elevated levels of inflammatory factors, especially IL-2 and IL-2ra, have a potential causal relationship with myopia susceptibility, providing new insights into the pathogenesis of myopia.

Posterior scleral reinforcement surgery effectively slows the rate of high myopic progression in children

PURPOSE

To investigate the rate of axial length elongation and high myopia progression in operated eyes before and after posterior scleral reinforcement (PSR) surgery.

METHODS

This was a retrospective study. Children with pathological myopia treated with PSR at Beijing Tongren Hospital between May 2013 and May 2020 were recruited into the PSR surgery group. Children matched for age and myopia were recruited into the control group. All children underwent comprehensive ophthalmologic examinations. The presurgical and postsurgical rates of axial length elongation and myopic (spherical equivalent) progression were calculated.

RESULTS

A total of 35 PSR patients were included in the study. The mean age was 6.5±3.0 years (range 2 to 14 years). Mean follow-up was 544 days (range 216 to 1657 days). The rate of axial length elongation was significantly less after posterior scleral reinforcement surgery (0.505±0.048mm per year prior to surgery; 0.382±0.045mm per year after surgery, P<0.001). The rate of myopic progression decreased after posterior scleral reinforcement surgery (1.162±0.118 D per year prior to surgery; 0.153±0.437 D per year after surgery, P=0.0239). There was no statistically significant difference in axial length elongation or myopic progression between pre-inclusion and post-inclusion in the control group. Moreover, the children's best-corrected visual acuity was significantly improved after posterior scleral reinforcement surgery (P<0.001).

CONCLUSION

Posterior scleral reinforcement surgery effectively decreased the rate of high myopic progression and axial length elongation in children.

The effect of individualized ocular refraction customized spectacle lenses on myopia control in schoolchildren: A 1-year randomised clinical trial

PURPOSE

The aim of this study was to investigate the effect of individualized ocular refraction customized (IORC) spectacle lenses with different actual amounts of peripheral myopic defocus (MD) on myopia control over 1 year. These lenses compensate for the original peripheral refraction via the free-form surface on the back of the lens.

METHODS

This 1-year, double-masked randomised clinical trial included 184 myopic schoolchildren aged 8-12 years. Participants were randomised to receive IORC lenses with high (IORC-H group, +4.50 D), medium (IORC-M group, +3.50 D) or low (IORC-L group, +2.50 D) MD or single-vision (SV) lenses. The spherical equivalent refractive error (SER) and axial length (AL) were measured at baseline and 6-monthly intervals.

RESULTS

After 1 year, the mean (SD) changes in SER were -0.18 (0.37), -0.36 (0.37), -0.52 (0.39) and -0.60 (0.42) D for the IORC-H, IORC-M, IORC-L and SV groups, respectively. Compared with the SV group, the effects of slowing myopia progression were 70%, 40% and 13% for the IORC-H (difference of 0.47 D, p < 0.001), IORC-M (difference of 0.32 D, p = 0.001) and IORC-L (difference of 0.15 D, p > 0.05) groups, respectively. The mean (SD) changes in AL were 0.12 (0.16), 0.23 (0.17), 0.29 (0.17) and 0.36 (0.17) mm for the IORC-H, IORC-M, IORC-L and SV groups, respectively. The axial elongation was 67%, 36% and 19% lower in the IORC-H (difference of 0.25 mm, p < 0.001), IORC-M (difference of 0.15 mm, p < 0.001) and IORC-L (difference of 0.10 mm, p = 0.04) groups, respectively, compared with the SV group. The IORC-H group exhibited significantly less axial elongation than the IORC-M and IORC-L groups (p = 0.01 and p < 0.001, respectively).

CONCLUSION

Compared with the IORC-M and IORC-L lenses, the IORC-H lens was found to have superior efficacy in inhibiting myopic progression and slowing eye growth in schoolchildren, with better myopia control efficacy in younger children.

Anisomyopia and orthokeratology for myopia control - Axial elongation and relative peripheral refraction

PURPOSE

To investigate axial elongation (AE) and changes in relative peripheral refraction (RPR) in anisomyopic children undergoing orthokeratology (ortho-k).

METHODS

Bilateral anisomyopic children, 7-12 years of age, were treated with ortho-k. Axial length (AL) and RPR, from 30° nasal (N30°) to 30° temporal (T30°), were measured at baseline and every 6 months over the study period. AE, changes in RPR and changes in the interocular AL difference were determined over time.

RESULTS

Twenty-six of the 33 subjects completed the 2-year study. The AE of the higher myopic (HM) eyes (at least 1.50 D more myopia than the other eye) (0.26 ± 0.29 mm) was significantly smaller than for the less myopic (LM) eyes (0.50 ± 0.27 mm; p = 0.003), leading to a reduction in the interocular difference in AL (p = 0.001). Baseline RPR measurements in the HM eyes were relatively more hyperopic at T30°, N20° and N30° (p ≤ 0.02) and greater myopic shifts were observed at T20° (p < 0.001), T30° (p < 0.001), N20° (p = 0.02) and N30° (p = 0.01) after lens wear. After 2 years of ortho-k lens wear, temporal-nasal asymmetry increased significantly, being more myopic at the temporal locations in both eyes (p < 0.001), while AE was associated with the change in RPR at N20° (β = 0.134, p = 0.01). The interocular difference in AE was also positively associated with the interocular difference in RPR change at N30° (β = 0.111, p = 0.02).

CONCLUSIONS

Ortho-k slowed AE in bilateral anisomyopia, with slower growth in the HM eyes leading to a reduction in interocular AL differences. After ortho-k, RPR changed from hyperopia to myopia, with greater changes induced in the HM eyes, and slower AE was associated with a more myopic shift in RPR, especially in the nasal field of both eyes.

Five-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study: Phase 4 Report

PURPOSE

To evaluate (1) the long-term efficacy of low-concentration atropine over 5 years, (2) the proportion of children requiring re-treatment and associated factors, and (3) the efficacy of pro re nata (PRN) re-treatment using 0.05% atropine from years 3 to 5.

DESIGN

Randomized, double-masked extended trial.

PARTICIPANTS

Children 4 to 12 years of age originally from the Low-Concentration Atropine for Myopia Progression (LAMP) study.

METHODS

Children 4 to 12 years of age originally from the LAMP study were followed up for 5 years. During the third year, children in each group originally receiving 0.05%, 0.025%, and 0.01% atropine were randomized to continued treatment and treatment cessation. During years 4 and 5, all continued treatment subgroups were switched to 0.05% atropine for continued treatment, whereas all treatment cessation subgroups followed a PRN re-treatment protocol to resume 0.05% atropine for children with myopic progressions of 0.5 diopter (D) or more over 1 year. Generalized estimating equations were used to compare the changes in spherical equivalent (SE) progression and axial length (AL) elongation among groups.

MAIN OUTCOMES MEASURES

(1) Changes in SE and AL in different groups over 5 years, (2) the proportion of children who needed re-treatment, and (3) changes in SE and AL in the continued treatment and PRN re-treatment groups from years 3 to 5.

RESULTS

Two hundred seventy (82.8%) of 326 children (82.5%) from the third year completed 5 years of follow-up. Over 5 years, the cumulative mean SE progressions were -1.34 ± 1.40 D, -1.97 ± 1.03 D, and -2.34 ± 1.71 D for the continued treatment groups with initial 0.05%, 0.025%, and 0.01% atropine, respectively (P = 0.02). Similar trends were observed in AL elongation (P = 0.01). Among the PRN re-treatment group, 87.9% of children (94/107) needed re-treatment. The proportion of re-treatment across all studied concentrations was similar (P = 0.76). The SE progressions for continued treatment and PRN re-treatment groups from years 3 to 5 were -0.97 ± 0.82 D and -1.00 ± 0.74 D (P = 0.55) and the AL elongations were 0.51 ± 0.34 mm and 0.49 ± 0.32 mm (P = 0.84), respectively.

CONCLUSIONS

Over 5 years, the continued 0.05% atropine treatment demonstrated good efficacy for myopia control. Most children needed to restart treatment after atropine cessation at year 3. Restarted treatment with 0.05% atropine achieved similar efficacy as continued treatment. Children should be considered for re-treatment if myopia progresses after treatment cessation.

FINANCIAL DISCLOSURE(S)

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

Mediation effect of sleep time on the association between outdoor activity and myopia in Chinese children and adolescents: a cross-sectional study

BACKGROUND

This study aimed to assess the association between outdoor activity and myopia among children and adolescents and investigate whether sleep time could mediate this relationship.

METHODS

This cross-sectional study was performed on students aged 4-16 years in China, from August 2021 to January 2022. Outdoor activity was assessed by the Assessment Questionnaire of Exposure to Sunlight Activities for Students (AQESAS). Binary logistic regression combined with the mediation analysis was used to analyze the association of AQESAS with myopia and the mediating effect of sleep time on this relationship.

RESULTS

The prevalence of myopia was 53.51% (N = 1609). Multivariate logistic regression analysis showed that more sleep time (OR = 0.794, 95%CI: 0.707-0.893) and a higher score of AQESAS (OR = 0.989, 95%CI: 0.981-0.996) were significantly associated with a decreased risk of myopia. Mediation analysis revealed that sleep time plays a mediating role in the association between outdoor activity and myopia (ACME = -0.0006, P < 0.001), and the mediation proportion was 19.7%.

CONCLUSION

Outdoor activity affects myopia directly and indirectly through sleep time. The result suggested that children may be able to reduce the risk of myopia by promoting sleep through increased awareness of outdoor activity and exposure to sunlight.

The Effect of Alternating Monocular Instillation of 0.125% Atropine in Korean Children with Progressive Myopia

Objectives: To identify the effect of alternating monocular instillation (AMI) of 0.125% atropine in Korean children with progressive myopia. Methods: This retrospective single-center study included 120 children with progressive myopia. A total of 60 children (mean age 9.2 ± 2.0 years) wearing glasses who received AMI of 0.125% atropine for one year were allocated to the treatment group. The remaining 60 children (mean age 9.2 ± 1.9 years) with the same refraction, SE, and axial length (AL) who did not receive any treatments except for wearing glasses were allocated to the control group. Ocular findings and the progression rate were compared between the groups pre- and post-treatment, and adverse events were investigated in the treatment group. Results: The mean spherical equivalent (SE) at baseline was -3.87 ± 1.55 D in the control group and -3.90 ± 1.56 D in the treatment group. Pre-treatment SE, age, and AL were similar between the groups; however, post-treatment SE and AL changes were smaller in the treatment group (-0.36 ± 0.46 D/y, 0.21 ± 0.20 mm/year in the treatment group vs. -1.02 ± 0.57 D/y, 0.51 ± 0.20 mm/year in the control group) (Ps < 0.001). The pre-treatment progression rate diminished in the treatment group compared to the control group after one year (p < 0.001), and the changes in pupil size under mesopic and photopic conditions in the treatment group increased by 0.03 ± 0.05 mm and 0.76 ± 0.90 mm, respectively. Regarding adverse events, a tingling sensation was noted in two patients (3.3%) in the treatment group. Conclusions: Alternating monocular 0.125% atropine eye drop instillation may be effective and suitable for progressive myopia in Korean children.

Efficacy of outdoor interventions for myopia in children and adolescents: a systematic review and meta-analysis of randomized controlled trials

Objectives

The objective of this systematic review and meta-analysis was to evaluate the overall efficacy of outdoor interventions for myopia in children and adolescents, and to provide evidence for the prevention and control of myopia.

Methods

Randomized controlled trials of outdoor interventions for myopia in children and adolescents were identified using electronic databases and manual searches. The Revised Cochrane risk-of-bias tool for randomized trials (RoB 2) was used to assess risk of bias in randomized controlled trials. A mean difference (MD) and a risk ratio (RR) with a 95% confidence interval (CI) were used to combine effect sizes. A sensitivity analysis was performed for each outcome using a stepwise elimination method to assess whether the pooled results were significantly affected by individual studies.

Results

The analysis included seven randomized controlled trials involving a total of 9,437 subjects. The meta-analysis showed marked and statistically significant improvements in spherical equivalent refraction (MD = 0.19; 95% CI 0.14 to 0.25; p < 0.01), axial length (MD = -0.09; 95% CI -0.13 to -0.05; p < 0.01), and myopia incidence (RR = 0.84; 95% CI 0.78 to 0.91; p < 0.01) following outdoor interventions.

Conclusion

Outdoor interventions effectively contributed to the prevention and control of myopia in children and adolescents, positively impacting spherical equivalent refraction, axial length, and myopia incidence. Outdoor interventions were characterized by low risk and high therapeutic benefits and could serve as alternative or adjuvant approaches to medication for the treatment of myopia. Considering the advantages in terms of safety and efficacy, outdoor interventions may be considered as a preferred intervention for the treatment of myopia in children and adolescents, while susceptibility to diseases associated with sunlight, particularly UV exposure, must be taken into account.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, Identifier CRD42024538695.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Assessment of optic disc morphological characteristics and related factors of highly myopic eyes in Chinese school-aged children

CLINICAL RELEVANCE

The morphological characteristics of the optic nerve head (ONH) in myopic eyes are a clinically significant issue, especially for high myopia in school-aged children, and this can be monitored using optical coherence tomography.

BACKGROUND

The purpose of this study is to investigate the morphological characteristics of ONH, and the factors associated with peripapillary choroidal thickness in Chinese school-aged high myopia children.

METHODS

A total of 48 patients, possessing 48 high myopia eyes and 48 contralateral low myopia eyes were enrolled. The ONH characteristic parameters, including peripapillary retinal nerve fibre layer thickness, peripapillary choroidal thickness, peripapillary choroidal blood flow density, Bruch's membrane opening (BMO) characteristic parameters were measured on optical coherence tomography scans.

RESULTS

Eyes with high myopia had a larger disc size, higher peripapillary atrophy area proportion, larger peripapillary atrophy area, larger BMO minimum rim width, lower peripapillary choroidal thickness compared with those contralateral low myopia eyes (all P < 0.001). The BMO distance and border length were longer, and border tissue angle was smaller in the high myopia eyes. The multivariate regression analysis revealed that border length, axial length, and border tissue angle were independently associated with peripapillary choroidal thickness (all P < 0.05); axial length was associated with peripapillary retinal nerve fibre layer thickness (P = 0.007).

CONCLUSION

The peripapillary atrophy area, BMO area, border length, BMO distance, and BMO minimum rim width increased, but peripapillary choroidal thickness, retinal nerve fibre layer thickness decreased with axial elongation of the globe in young myopia children. Longer axial length and border length were positively correlated with lower peripapillary choroidal thickness, and a smaller border tissue angle was positively correlated with lower peripapillary choroidal thickness were found in this study. Monitoring of border length and border tissue angle is essential in the early stages of myopia in children.

Frequency-dependent effects of 0.05% atropine eyedrops on myopia progression and peripheral defocus: a prospective study

BACKGROUND

Atropine, specifically 0.05% eyedrops, has proven effective in slowing myopia progression. This study aims to investigate peripheral refraction (PR) characteristics in myopic children treated with 0.05% atropine eyedrops at different frequencies.

METHODS

One hundred thirty-eight myopic children completed this one-year prospective study, randomly assigned to once daily (7/7), twice per week (2/7), or once per week (1/7) groups. Spherical equivalent (SE) and axial length (AL) were measured. PR was assessed using a custom-made Hartmann-Shack wavefront peripheral sensor, covering a visual field of horizontal 60° and vertical 36°. Relative peripheral refraction (RPR) was calculated by subtracting central from peripheral measurements.

RESULTS

After one year, SE increased more significantly in the 1/7 group compared to the 7/7 group (P < 0.001) and 2/7 group (P = 0.004); AL elongation was also greater in the 1/7 group compared to the 7/7 group (P < 0.001). In comparison with higher frequency groups, 1/7 group exhibited more myopic PR in the fovea and its vertical superior, inferior, and nasal retina; and less myopic RPR in the periphery retina after one-year (P < 0.05). Additionally, RPR in the 7/7 group demonstrated myopic shift across the entire retina, the 2/7 group in temporal and inferior retina, while the 1/7 group showed a hyperopic shift in the superior retina (P < 0.05). Moreover, myopic shift of RPR in the temporal retina is related to less myopia progression, notably in the 7/7 group (P < 0.05).

CONCLUSIONS

Atropine inhibits myopia progression in a frequency-dependent manner. The once-daily group showed the slowest myopia progression but exhibited more myopic shifts in RPR. Additionally, RPR in the temporal retina was related to myopia progression in all groups.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100043506. Registered 21 February 2021, https://www.chictr.org.cn/showproj.html?proj=122214.

Myopia trends among children and adolescents: a nationwide study in South Korea

PURPOSE

To evaluate gender disparities in the progression of myopia among children and adolescents in South Korea.

METHODS

Nationwide cross-sectional data of 1,190 subjects aged 10-18 years was obtained for the years of 2011 (baseline) and 2021 using the Korea National Health and Nutrition Examination Surveys. The prevalence of myopia, as well as data regarding age, household income, height, weight, body mass index, and age of menarche, were evaluated. Myopia was defined as a spherical equivalent (SE) ≤ -0.5 D.

RESULTS

The prevalence of myopia among boys was stable in 2021 compared to 2011, with rates of 53.7% and 52.8%, respectively (P = 0.372). Among girls, however, there was a statistically significant increase in myopia prevalence in 2021 compared to 2011, with rates of 73.7% and 51.6% (P < 0.001), respectively. Over 10 years, the adjusted prevalence ratio for myopia in boys was 1.11 (95% CI, 0.77-1.61), whereas myopia prevalence in girls underwent a 1.87-fold increase over the same period (95% CI, 1.30-2.69), and menarche at 12 years of age or older was associated with less myopia in girls (PR = 0.84; 95% CI, 0.72-0.99). The spherical equivalent refraction in girls increased significantly over the same 10-year period, from -1.09 ± 0.13 D to -1.58 ± 0.17 D (P < 0.017), whereas in boys, there was no significant difference (P = 0.604).

CONCLUSIONS

In our study cohort, the prevalence of myopia increased significantly among girls compared with boys over the course of decade. Additionally, an association between early menarche in girls and the prevalence of myopia was observed.

Peripheral Ganglion Cell Complex Thickness and Retinal Microvasculature in Myopia Using Wide-Field Swept-Source OCT

Purpose

This study aims to investigate the impact of axial elongation on ganglion cell complex thickness (GCCT) and retinal capillary density (CD) using wide-field swept-source optical coherence tomography angiography.

Methods

A retrospective cross-sectional analysis was conducted involving 506 eyes. Fovea-centered scans were obtained to assess the subregional GCCT and capillary density across the whole retina, the superficial capillary plexus (SCP), and deep capillary plexus (DCP) among three groups: normal control, high myopia (HM) eyes with axial length < 28 mm, and HM eyes with axial length > 28 mm. Regional variations (central vs. peripheral, quadrants difference [superior, inferior, nasal, and temporal]) were analyzed.

Results

In HM eyes with axial length > 28 mm, GCCT and retinal CD exhibit a general decline in most regions (P < 0.05). In HM eyes with axial length < 28 mm, significant reductions were observed specifically in peripheral regions, as in the GCCT beyond the 3 × 3 mm2 area and CD in the 9-12 mm whole retina, 9-12 mm superior SCP, and 6-12 mm DCP (P < 0.05). Maximum GCCT and retinal CD reduction with axial elongation was observed in subregions beyond 6 × 6  mm2.

Conclusions

GCCT beyond the 3 × 3 mm2 area and peripheral retinal CD beyond the 6 × 6  mm2 area were more susceptible to axial elongation and are thereby deserving of particular attention.

Translational Relevance

It is necessary to evaluate different regions during the clinical assessment of the effect of myopia on the fundus and pay close attention to the peripheral retina.

Analyzing the topological properties of resting-state brain function network connectivity based on graph theoretical methods in patients with high myopia

AIM

Recent imaging studies have found significant abnormalities in the brain's functional or structural connectivity among patients with high myopia (HM), indicating a heightened risk of cognitive impairment and other behavioral changes. However, there is a lack of research on the topological characteristics and connectivity changes of the functional networks in HM patients. In this study, we employed graph theoretical analysis to investigate the topological structure and regional connectivity of the brain function network in HM patients.

METHODS

We conducted rs-fMRI scans on 82 individuals with HM and 59 healthy controls (HC), ensuring that the two groups were matched for age and education level. Through graph theoretical analysis, we studied the topological structure of whole-brain functional networks among participants, exploring the topological properties and differences between the two groups.

RESULTS

In the range of 0.05 to 0.50 of sparsity, both groups demonstrated a small-world architecture of the brain network. Compared to the control group, HM patients showed significantly lower values of normalized clustering coefficient (γ) (P = 0.0101) and small-worldness (σ) (P = 0.0168). Additionally, the HM group showed lower nodal centrality in the right Amygdala (P < 0.001, Bonferroni-corrected). Notably, there is an increase in functional connectivity (FC) between the saliency network (SN) and Sensorimotor Network (SMN) in the HM group, while the strength of FC between the basal ganglia is relatively weaker (P < 0.01).

CONCLUSION

HM Patients exhibit reduced small-world characteristics in their brain networks, with significant drops in γ and σ values indicating weakened global interregional information transfer ability. Not only that, the topological properties of the amygdala nodes in HM patients significantly decline, indicating dysfunction within the brain network. In addition, there are abnormalities in the FC between the SN, SMN, and basal ganglia networks in HM patients, which is related to attention regulation, motor impairment, emotions, and cognitive performance. These findings may provide a new mechanism for central pathology in HM patients.

Prevalence and associated factors of myopia among adolescents aged 12-15 in Shandong Province, China: a cross-sectional study

Myopia is a growing concern worldwide, especially among adolescents. This study aimed to investigate the prevalence and associated factors of myopia in adolescents aged 12-15 in Shandong Province, China. This cross-sectional study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines and involved stratified random cluster sampling of 128,678 students from 186 middle schools across 17 cities in Shandong Province. Data collection was conducted from March to April 2024. We excluded students with organic eye diseases, abnormal binocular vision functions, or a history of eye injuries or surgeries. Myopia was assessed using the standard logarithmic visual acuity chart and autorefractor without inducing ciliary muscle paralysis. A comprehensive questionnaire survey was conducted to gather demographic characteristics and daily life behaviors. With the chi-squared test for univariable analysis and multivariable logistic regression for identifying significant factors. This study included 126,375 participants, with a gender distribution of 51.02% male and 48.98% female. The overall prevalence of myopia was 71.34%. Higher prevalence was observed in girls (72.26%) compared to boys (70.45%), and the prevalence increased with age, peaking at 73.12% in 15-year-olds. Urban residents had a higher prevalence (71.86%) than rural (70.39%). Factors such as increased frequency of eye usage while lying down or leaning forward, frequent use of eyes while walking or riding in a car, prolonged screen time, and extended homework duration were associated with higher odds of developing myopia. Conversely, higher frequency of outdoor exercise, maintaining proper posture during reading and writing, greater distance from eyes to screen, and longer sleep duration were associated with lower odds. Additionally, female gender, older age, urban residence, and parental history of myopia increased the risk. The high prevalence of myopia among adolescents in Shandong Province was influenced by a combination of demographic, behavioral, and environmental factors. The study highlighted the importance of lifestyle modifications, such as increasing outdoor activities and maintaining proper visual habits, limiting the duration of screen exposure and homework sessions, and extending sleep duration, to mitigate the risk of developing myopia. These findings underscored the need for targeted public health interventions and educational campaigns to address this significant public health issue.

Light exposure therapy for myopia control: a systematic review and Bayesian network meta-analysis

AIMS

To compare and rank the myopia control effects of different light wavelengths in children using a systematic review and Bayesian network meta-analysis (Bayesian NMA).

METHODS

The review protocol was registered with PROSPERO. We searched PubMed, EMBASE and MEDLINE for relevant clinical and animal studies published as of 2 February 2023. We included studies comparing red, violet or full-spectrum light with controls. Data extracted included descriptive statistics and study outcomes (axial length (AL) elongation and progression of spherical equivalent (SE) refraction). After quality assessment, estimates of treatment effect outcomes (mean differences (MDs) and 95% CIs) were first pooled for the animal and clinical studies in a traditional meta-analysis. To compare and rank the different light wavelengths, the Bayesian NMA was then conducted for all the included clinical studies (12 studies) and separately for only randomised controlled trials (8 studies). MDs, 95% credible intervals (CrIs) and ranks of the various light wavelengths were estimated in the Bayesian NMA.

RESULTS

When all clinical studies were included in the Bayesian NMA (12 studies), only red-light significantly slowed AL elongation, MD (95% CrI), -0.38 mm (-0.59 mm to -0.16 mm)/year and SE refraction progression, 0.72D (0.35D to 1.10D)/year compared with controls. It remained the only significant intervention when effect sizes from only RCTs (eight studies) were separately combined, (-0.28 mm (-0.40 mm to -0.15 mm)/year and 0.57D (0.22D to 0.92D)/year, for AL and SE refraction, respectively).

CONCLUSION

Myopia control efficacy varied among different wavelengths of light, with red light ranked as the most effective.

PROSPERO REGISTRATION NUMBER

Clinical studies: CRD42022368998; animal studies: CRD42022368671.

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.

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.

Positive and Negative Associations of Myopia with Ocular Diseases in Population-Based Studies

PURPOSE

Prevalence of myopia and vision impairment due to myopic macular degeneration and myopia-related optic neuropathies have markedly increased worldwide. We evaluated whether myopia is associated with other ocular disorders.

DESIGN

Population-based studies conducted in Russia, China, and India.

PARTICIPANTS

The Russian Ural Eye and Medical Study (UEMS) and the Beijing Eye Study (BES) included 5899 individuals and 4439 individuals (all aged 40+ years), respectively, and the Central India Eye and Medical Study (CIEMS) consisted of 4711 individuals aged 30+ years. The studies were conducted in rural and urban regions in Bashkortostan/Russia, Nagpur/India, and Beijing/China.

METHODS

The participants underwent a series of ophthalmological and general medical examinations.

MAIN OUTCOME MEASURES

Axial length as a surrogate for myopia and prevalence of diabetic retinopathy (DR), age-related macular degeneration (AMD), angle-closure glaucoma (ACG), and open-angle glaucoma (OAG).

RESULTS

In the UEMS, DR prevalence (odds ratio [OR], 0.73), AMD prevalence (OR, 0.85), and ACG prevalence (OR, 0.72) decreased, and OAG prevalence (OR, 1.65) increased with longer axial length in multivariable analyses. In the CIEMS, lower AMD prevalence (OR, 0.81) and lower ACG prevalence (OR, 0.55), and higher OAG prevalence (OR, 1.45) were associated with longer axial length. Diabetic retinopathy prevalence (0.33%) was too low for statistical analysis in the CIEMS. In the BES, prevalence (OR, 0.64) and 10-year incidence of DR (OR, 0.48) and prevalence (OR, 0.83) and 5-year incidence of AMD (OR, 0.996) decreased, and prevalence (OR, 1.35) and 10-year incidence of OAG (OR, 1.40) increased with longer axial length. In all 3 studies, the association between higher OAG prevalence and longer axial length was nonlinear with a slight increase for the moderate myopia range and a steep increase in the highly myopic range.

CONCLUSIONS

Myopia is associated with a lower prevalence of DR, AMD, and ACG and a lower incidence of DR and AMD, whereas high myopia more than moderate myopia is associated with a higher prevalence and incidence of OAG. Future studies may assess whether in myopia (in particular, in moderate myopia), the myopia-related advantages, that is, lower prevalence of DR, AMD, and ACG, may outweigh the increased risks for OAG and other myopia-related disorders.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Impact of defocus incorporated multiple segments (DIMS) spectacle lenses for myopia control on quality of life of the children: a qualitative study

OBJECTIVE

To assess the impact of DIMS (defocus incorporated multiple segments) spectacle lenses on the quality of life of children using it.

METHODS

Separate in-depth interviews were conducted with children using DIMS as a myopia control strategy for at least 1 month and their parents based on prepared guides. The recorded audio of the interviews was transcribed, and the significant data points were coded using a hybrid approach, that is, both the inductive and deductive coding methods were used to identify themes. The generated codes were further grouped, categorised and finally fitted as per relevance into the subdomains of the four domains of the WHO Quality of Life-Brief framework, namely the domains of social relationships, physical, psychological and environmental health.

RESULTS

A total of 29 interviews were conducted, 15 with children (mean age: 12.47±2.13 years) and 14 with parents. Thematic analysis was done and a total of 63 codes were generated with 2, 16, 17 and 28 codes aligning to the domains of social relationships, environmental, psychological and physical health, respectively. Most parents did not notice any change in their child's visual behaviour, yet children did experience symptoms such as peripheral blurred vision, eyestrain, headache, haloes and more during the adaptation period. High-cost, scratch-prone nature and difficulty in procurement were a few concerns raised by parents.

CONCLUSIONS

Participants were satisfied with most of the facets of social relationships, physical and psychological health domains. However, a few facets such as quality, accessibility and finance of the environmental health domain need improvement.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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