Spatial epidemiological characteristics and driving factors of myopia among school-age children based on geographical detector: a national study

The present study aimed to examine the spatial characteristics of myopia and identify the socioeconomic and environmental factors influencing its prevalence. Myopia prevalence among children of school age of Han ethnicity in China was 56.6% in 2019, with the highest and lowest prevalence's in Shandong (66.8%) and Guizhou (47.3%), respectively. There was a spatial aggregation of myopia prevalence in China. Environmental factors (atmospheric PM2.5 concentration and forest coverage) and socioeconomic factors (gross domestic product per capita, per capita disposable income, hospital beds per thousand people, and Engel coefficient) have significant influences on myopia prevalence. The interaction of each factor on myopia showed nonlinear enhancement. Myopia prevalence among children of school age was spatially clustered, and environmental and socioeconomic conditions are associated with myopia prevalence. Our findings provide novel perspectives for the comprehensive prevention and control of myopia.

Heritability and Genetic Factors of Astigmatism and Corneal Curvature: A Systematic Review and Meta-analysis

PURPOSE

To systematically review and meta-analyze all reported heritability studies of refractive astigmatism (RA), corneal astigmatism (CA) and corneal curvature (CC), and evaluate the existing genetic associations of RA, CA and CC.

DESIGN

Systematic review and meta-analysis (PROSPERO ID: CRD42023447370).

METHODS

Studies that reported the heritability and genetic associations of RA, CA and/or CC were identified from PubMed, Web of Science and EMBASE (from inception to October 1, 2023). Newcastle-Ottawa Scale criteria was used to assess the risk of bias. Meta-analyses of heritability were conducted using random-effects model for mean difference. All current genetic associations were catalogued according to level of statistical significance.

RESULTS

Pooled heritabilities were moderate for RA (h2 = 0.46, 95% CI: 0.27-0.65), CA (h2 = 0.48, 95% CI: 0.38-0.58) and CC (h2 = 0.64, 95% CI: 0.53-0.76). Subgroup analyses revealed significant differences between analysis methods (CA: P < .01; CC: P = .03) and populations (CA: P < .01; CC: P < .01) in both CA and CC, and between age groups in CA (P < .01). Totally 50 single-nucleotide polymorphisms (SNPs) in 10 genes have been reported with overlapping associations with RA, CA, and/or CC, with BMP3, FMNL2, HERC2, PROX1-AS1, and ZC3H11B associated with RA and CA, FBN1, NHSL1, and PDGFRA with CA and CC, TRAF3IP1 with RA and CC, and CASC15 with RA, CA, and CC.

CONCLUSIONS

This study confirms moderate heritabilities of RA, CA and CC. Through evaluating overlapping SNPs or genes between these three phenotypes, we prioritized 50 SNPs in 10 genes as candidate variants for further validation. These findings highlight the complex genetic architecture of astigmatism and indicate shared and distinct genetic markers for different astigmatism-related corneal parameters. Future studies in different populations and functional studies evaluating the roles of the involved genes in astigmatism are warranted.

Diurnal gene expression patterns in retina and choroid distinguish myopia progression from myopia onset

The world-wide prevalence of myopia (nearsightedness) is increasing, but its pathogenesis is incompletely understood. Among many putative mechanisms, laboratory and clinical findings have implicated circadian biology in the etiology of myopia. Consistent with a circadian hypothesis, we recently reported a marked variability in diurnal patterns of gene expression in two crucial tissues controlling post-natal refractive development - the retina and choroid-at the onset of form-deprivation myopia in chick, a widely studied and validated model. To extend these observations, we assayed gene expression by RNA-Seq in retina and choroid during the progression of established unilateral form-deprivation myopia of chick. We assayed gene expression every 4 hours during a single day from myopic and contralateral control eyes. Retinal and choroidal gene expression in myopic vs. control eyes during myopia progression differed strikingly at discrete times during the day. Very few differentially expressed genes occurred at more than one time in either tissue during progressing myopia. Similarly, Gene Set Enrichment Analysis pathways varied markedly by time during the day. Some of the differentially expressed genes in progressing myopia coincided with candidate genes for human myopia, but only partially corresponded with genes previously identified at myopia onset. Considering other laboratory findings and human genetics and epidemiology, these results further link circadian biology to the pathogenesis of myopia; but they also point to important mechanistic differences between the onset of myopia and the progression of established myopia. Future laboratory and clinical investigations should systematically incorporate circadian mechanisms in studying the etiology of myopia and in seeking more effective treatments to normalize eye growth in children.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anterior chamber and angle characteristics in Chinese children (6-11 years old) with different refractive status using swept-source optical coherence tomography

BACKGROUND

The anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT).

METHODS

In a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 μm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D).

RESULTS

Out of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6-11 years) were included. The mean SER and AL were - 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson's correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL.

CONCLUSION

In primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.

Research progress of photo-crosslink hydrogels in ophthalmology: A comprehensive review focus on the applications

Hydrogel presents a three-dimensional polymer network with high water content. Over the past decade, hydrogel has developed from static material to intelligent material with controllable response. Various stimuli are involved in the formation of hydrogel network, among which photo-stimulation has attracted wide attention due to the advantages of controllable conditions, which has a good application prospect in the treatment of ophthalmic diseases. This paper reviews the application of photo-crosslink hydrogels in ophthalmology, focusing on the types of photo-crosslink hydrogels and their applications in ophthalmology, including drug delivery, tissue engineering and 3D printing. In addition, the limitations and future prospects of photo-crosslink hydrogels are also provided.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

A Two-Decade Bibliometric Analysis of Laser in Ophthalmology: From Past to Present

Background

Laser therapy has been proven as an effective technique for managing ophthalmological disorders. To guide future research, we conducted a bibliometric analysis of laser applications in eye diseases from 1990 to 2022, aiming to identify key themes and trends.

Methods

We retrieved 3027 publications from the Web of Science Core Collection (WoSCC). Bibliometrix was used for science mapping of the literature, while VOSviewer and CiteSpace were applied to visualize co-authorship, co-citation, co-occurrence, and bibliographic coupling networks.

Results

From a co-citation reference network, we identified 52 distinct clusters. Our analysis uncovered three main research trends. The first trend revolves around the potential evolution of corneal laser surgery techniques, shifting from the treatment of refractive errors to broader applications in biomedical optics. The second trend illustrates the advancement of laser applications in treating a range of disorders, from retinal and ocular surface diseases to glaucoma. The third trend focuses on the innovative uses of established technologies.

Conclusion

This study offers significant insights into the evolution of laser applications in ophthalmology over the past 30 years, which will undoubtedly assist scientists in directing further research in this promising field.

Crosstalk between heredity and environment in myopia: An overview

In recent years, the prevalence of myopia has gradually increased, and it has become a significant global public health problem in the 21st century, posing a serious challenge to human eye health. Currently, it is confirmed that the development of myopia is attributed to the combined action of genes and environmental factors. Thus, elucidating the risk factors and pathogenesis of myopia is of great significance for the prevention and control of myopia. To elucidate the impact of gene-environment interaction on myopia, we used the Pubmed database to search for literature related to myopia. Search terms are as follows: myopia, genes, environmental factors, gene-environment interaction, and treatment. This paper reviews the effects of gene and environmental interaction on myopia.

Osmosis as nature's method for establishing optical alignment

For eyes to maintain optimal focus, precise coordination is required between lens optics and retina position, a mechanism that in vertebrates is governed by genetics, visual feedback, and possibly intraocular pressure (IOP).1 While the underlying processes have been intensely studied in vertebrates, they remain elusive in arthropods, though visual feedback may be unimportant.2 How do arthropod eyes remain functional while undergoing substantial growth? Here, we test whether a common physiological process, osmoregulation,3 could regulate growth in the sophisticated camera-type eyes of the predatory larvae of Thermonectus marmoratus diving beetles. Upon molting, their eye tubes elongate in less than an hour, and osmotic pressure measurements reveal that this growth is preceded by a transient increase in hemolymph osmotic pressure. Histological evaluation of support cells that determine the lens-to-retina spacing reveals swelling rather than the addition of new cells. In addition, as expected, treating larvae with hyperosmotic media post-molt leads to far-sighted (hyperopic) eyes due to a failure of proper lengthening of the eye tube and results in impaired hunting success. This study suggests that osmoregulation could be of ubiquitous importance for properly focused eyes.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Characteristics of myopic and hyperopic eyes in patients with antimetropia

CLINICAL RELEVANCE

Antimetropia is a rare type of anisometropia in which one eye is myopic and the fellow is hyperopic, This optical condition condition permits the evaluation of both sides of the emmetropisation process failure in the same individual by minimising genetic and environmental factors.

BACKGROUND

This study aimed to evaluate the ocular biometric, retinal, and choroidal characteristics of myopic and hyperopic eyes of antimetropic subjects older than six years.

METHODS

In this retrospective study, myopic and hyperopic eyes of 29 antimetropic patients with a spherical equivalent (SE) difference of at least 2.00D between the eyes were included. Axial length (AL), mean corneal keratometry, anterior chamber depth, the proportion of anterior chamber depth in AL, crystalline lens power, central macular thicknesses, disc-to-fovea distance, fovea-disc angle, peripapillary retinal nerve fibre layer (RNFL) thicknesses, and subfoveal choroidal features were compared between the eyes. The prevalence of amblyopia was determined. Refractive parameters and total astigmatic profile were evaluated in eyes with and without amblyopia.

RESULTS

The median absolute SE and AL differences between the eyes were 3.50D (interquartile range:1.75) and 1.18 mm (interquartile range:0.76), respectively (p < 0.001). Myopic eyes had lower crystalline lens power and proportion of anterior chamber depth in AL, and longer disc-to-fovea distance. Macular thicknesses, global RNFL, and temporal RNFL were thicker in myopic eyes, and there was no difference in other RNFL quadrants. Despite the increase in the choroidal vascularity index, other choroidal parameters were decreased in myopic eyes. Amblyopia was found in three of the myopic eyes and seven of the hyperopic eyes (p = 0.343). The highest interocular SE and AL difference and the highest frequency of anisoastigmatism were observed in patients with amblyopia in the myopic eye.

CONCLUSION

Each ocular structure may respond differently to, or may be affected differently by, ametropic conditions.

Association between hyperglycemia during pregnancy and offspring's refractive error: A focused review

This review article explores the relationship between hyperglycemia during pregnancy and the visual development of offspring, specifically focusing on refractive error. The authors conducted a comprehensive search for relevant articles in various databases and assessed the methodological quality of the included studies. The findings consistently indicate that hyperglycemia during pregnancy can have a detrimental impact on the structural and functional aspects of visual development in offspring. The intrauterine hyperglycemic environment appears to negatively affect the retina and lens, leading to refractive errors. In conclusion, there is likely an association between hyperglycemia during pregnancy and the development of refractive errors in offspring.

Temperament impact on eating disorder symptoms and habit formation: a novel model to inform treatment

BACKGROUND

Temperament has long been described as the biological dimension of personality. Due to advancing brain-imaging technology, our understanding of temperament has deepened and transformed over the last 25 years. Temperament combines genetic, neurobiological and trait research. Temperament has been included peripherally in some eating disorder (ED) treatment approaches but has been ignored by most. Temperament fills a fundamental treatment gap by clarifying who is more vulnerable to develop ED and why some individuals are susceptible to specific ED symptoms while others are not. In addition, temperament targets possible treatment solutions.

MAIN TEXT

There is a need for a novel model that incorporates and explores the role of temperament in ED treatment intervention. This paper is a metaphoric temperament model to inform treatment intervention. It describes how temperament traits influences new decisions which impact new behavioural responses. In turn, it neurobiologically tracks how and why the brain efficiently transforms new decisions into new habits. This model integrates both temperament and habit research to explore (a) what temperament is; (b) how new decisions develop into habits neurobiologically; (c) that the brain wires destructive symptoms into habits in the same way that it wires healthy/productive behaviours into habits; (d) traits that trigger ED symptoms are the same traits that influence productive behaviours; and in regard to treatment implications (e) when treatment structure and intervention target client temperaments, the potential for new healthy "trait-syntonic" habits could develop.

CONCLUSIONS

This paper introduces a metaphoric model that synthesizes and integrates temperament neurobiological and trait findings with ED symptoms, habits, and client trait-based solutions. The model synthesizes and integrates different research domains to establish a brain-based foundation to inform treatment intervention. The model targets clients' temperament traits as central collections of innate self-expressions that could be utilized as tools to redirect client trait-syntonic ED responses into trait-syntonic productive outcomes. The brain bases of temperament and habit formation serve as a biological foundation for ED treatment intervention.

Analysis of factors related to the development of ocular biometric parameters in Chinese children aged 6-10 years: a cross-sectional study

OBJECTIVES

Emmetropia depends on the precise coordination of ocular biometry, including axial length (AL), corneal curvature, lens thickness and anterior chamber depth (ACD). Disruption of this coordination leads to refractive errors such as myopia. This article aimed to determine the factors affecting ocular biometry and myopia development in young children.

DESIGN

A cross-sectional study.

SETTING

This study was conducted in a primary school in the Yanqing district of Beijing, China.

PARTICIPANTS

792 students in grades 1-3 without hyperopia (>+2.00 D), strabismus, or amblyopia were selected.

EXCLUSIONS

students had conditions affecting best corrected visual acuity and whose guardians refused to provide informed consent. Ocular biometric measurements and non-cycloplegia autorefraction were performed. The questionnaire addressed factors such as perinatal factors and environmental factors.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOMES

Ocular biometry and myopia.

RESULTS

According to the multivariate logistic regression analysis, electronic screen use >2 hours/day (OR=2.175, p=0.013), paternal myopia (OR=1.761, p=0.002), maternal myopia (OR=1.718, p=0.005), taller height (OR=1.071, p<0.001), maternal education (OR=0.631, p=0.012) and maternal gestational hypertension (OR=0.330, p=0.042) were associated with myopia. AL was affected by female sex (OR=0.295, p<0.001), older age (OR=1.272, p=0.002) and taller height (OR=1.045, p<0.001). Female sex (OR=0.509, p<0.001), taller height (OR=1.046, p<0.001), use of electronic screens >2 hours each day (OR=3.596, p<0.001) and time spent outdoors >2 hours each day (OR=0.431, p=0.001) influenced ACD incidence. Central corneal thickness (CCT) was associated with older age (OR=1.113, p=0.008), paternal education (OR=1.474, p=0.007), premature birth (OR=0.494, p=0.031), history of blue light therapy in infancy (OR=0.636, p=0.041) and history of incubator therapy in infancy (OR=0.263, p=0.009). Only sex influenced corneal curvature.

CONCLUSIONS

The factors associated with myopia were partly related to ACD and AL, and perinatal factors were associated with myopia and CCT.

TRIAL REGISTRATION NUMBER

ChiCTR2200065398.

Urban greenspace and visual acuity in schoolchildren: a large prospective cohort study in China

BACKGROUND

Greenspace is known to have a positive impact on human health and well-being, but its potential effects on visual acuity have not been extensively studied.

OBJECTIVES

Our aim was to examine the relationship between long-term greenspace exposure and visual acuity in children, while also exploring the potential mechanisms in this association.

METHODS

We conducted this prospective cohort study based on the Children's growth environment, lifestyle, physical, and mental health development project (COHERENCE), which screened 286,801 schoolchildren in Guangzhou, China, starting in the 2016/17 academic year and followed them up for three academic years (2017/18-2019/20). Visual acuity was measured using a standardized logarithmic chart, and visual impairment was defined as visual acuity worse than 0.0 logarithm of the minimum angle of resolution (LogMAR) units in the better eye. We used the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI), and the Enhanced Vegetation Index (EVI) to assess the greenspace surrounding child's geocoded home and school at each visit.

RESULTS

Our analysis indicated that higher greenspace exposure was associated with greater visual acuity z-score at baseline and with slower decline in visual acuity z-score during the 3-year follow-up. An interquartile range increase in home-school-based NDVI 300m was associated with a 7% decrease [hazard ratios (HRs): 0.93, 95% confidence interval (CI): 0.92, 0.94] in the risk of visual impairment. We also found that air pollution, physical activity, outdoor time, and recreational screen time partially mediated the greenspace-visual acuity association.

CONCLUSION

Our findings suggest that increasing greenspace exposure could benefit children's visual acuity development and reduce the risk of visual impairment by reducing air pollution and recreational screen time while increasing physical activity and outdoor time. All results could have potential policy implications, given the individual and societal burdens associated with visual impairment.

Nutritional intake, environmental factors, and their impact on myopia prevalence in Korean children aged 5-12 years

BACKGROUND

Myopia is a complex condition influenced by numerous factors, including genetic predisposition, environmental factors, and lifestyle choices. Although evidence indicates that certain dietary factors may influence the development of myopia, this relationship is still not completely understood and is a topic of ongoing research.

METHODS

This study analyzed the relationship between dietary habits, environmental factors, and the prevalence of myopia in a sample of 24,345 children aged 5-12 years from the seventh Korea National Health and Nutrition Examination Survey (KNHANES VII). The average daily intake of dietary nutrients associated with the refractive error status of the participants was analyzed using analysis of variance (GLM) and the Scheffe method for post-hoc comparison. Multiple logistic regression analysis was conducted between the participant's refractive error status and daily dietary nutrient intake, while taking into consideration the age, sex, BMI, parental myopia, and near-work hours.

RESULTS

The risk of myopia increased with age, especially notable between ages 11 and 12, and was higher in children with both parents having myopia. Dietary factors played a crucial role; children with myopia had significantly lower intake of fat, omega-3 fatty acids, and retinol but higher intake of other nutrients compared to emmetropic and hyperopic counterparts. High consumption of carbohydrates, protein, phosphorus, iron, potassium, and sodium was associated with increased myopia risk. High sodium intake was particularly associated with a 2.05-fold increased myopia risk.

CONCLUSIONS

This study highlights the significant role of diet and lifestyle choices in the development of myopia in children. Our findings suggest the importance of considering these specific factors in the management and prevention strategies for myopia, underscoring the need for targeted interventions in children's health and vision care.

A Mendelian randomization study on the causal relationship between smoking, alcohol consumption, and the development of myopia and astigmatism

The influence of environmental factors like smoking and alcohol on myopia and astigmatism is controversial. However, due to ethical concerns, alternative study designs are urgently needed to assess causal inference, as mandatory exposure to cigarettes and alcohol is unethical. Following comprehensive screenings, 326 single nucleotide polymorphisms (SNPs) related to myopia and astigmatism were included in the dataset. To validate the causal association between exposures such as cigarette smoking, alcohol consumption, and coffee intake, and outcomes namely astigmatism and myopia, five regression models were employed. These models encompassed MR-Egger regression, random-effects inverse-variance weighted (IVW), weighted median estimator (WME), weighted model, and simple model. The instrumental variables utilized in these analyses were the aforementioned SNPs. Apply Cochran's Q test to determine heterogeneity of SNPs; if heterogeneity exists, focus on IVW model results. The IVW model showed a 1.379-fold increase in the risk of astigmatism (OR = 1.379, 95%CI 0.822~2.313, P = 0.224) and a 0.963-fold increase in the risk of myopia (OR = 0.963, 95%CI 0.666~1.393, P = 0.841) for each unit increase in smoking. For each unit increase in coffee intake, the risk of astigmatism increased 1.610-fold (OR = 1.610, 95%CI 0.444~5.835, P = 0.469) and the risk of myopia increased 0.788-fold (OR = 0.788, 95%CI 0.340~1.824, P = 0.578). For each additional unit of alcohol consumption, the risk of astigmatism increased by 0.763-fold (OR = 0.763, 95%CI 0.380~1.530, P = 0.446), and none of the differences were statistically significant. However, for each unit of alcohol consumption, the risk of myopia increased by 1.597 times, and the difference was statistically significant (OR = 1.597, 95%CI 1.023~2.493, P = 0.039). The findings indicate that alcohol consumption is a risk factor for myopia but smoking and coffee intake do not affect its development. Additionally, there is no association between smoking, alcohol consumption, coffee intake, and the risk of astigmatism.

Association between dietary nutrient intake and prevalence of myopia in Korean adolescents: evidence from the 7th Korea National Health and Nutrition Examination Survey

Background

The rise in myopia prevalence, particularly among adolescents in East Asia, is a cause for concern. While a combination of environmental and genetic factors is understood to contribute to this trend, the role of dietary nutrients is not yet fully clarified.

Objective

To assess the potential association between the intake of specific nutrients and the prevalence of myopia in a large, population-based sample of Korean adolescents.

Methods

Data from 18,077 adolescents (average age: 15.05 ± 1.67 years; 51.7% male, 48.3% female) who participated in the 7th Korea National Health and Nutrition Examination Survey (KNHANES VII, 2016) were analyzed. Refractive error was measured using an auto-refractor-keratometer (KR-8800) without cycloplegia. Dietary intake of 14 nutrients was assessed through a 24-h personalized dietary recall method.

Results

The study revealed a myopia prevalence of 87.6% among the adolescents. Multivariable models adjusted for age, gender, BMI, and other confounding factors indicated that higher intakes of carbohydrates, proteins, cholesterol, sodium, and vitamin B2 were associated with an increased risk of myopia. Conversely, higher intake of vitamin C was found to be associated with a decreased risk.

Conclusion

The findings suggested a potential association between dietary nutrient intake and myopia prevalence in Korean adolescents. While the study did not establish a causal link, the differences in nutrient intake between the myopic and non-myopic groups could indicate that diet plays a role in the development or progression of myopia. Further research is warranted to corroborate these findings and explore the underlying mechanisms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of hyperopia with incident clinically significant depression: epidemiological and genetic evidence in the middle-aged and older population

AIMS

To investigate the association between hyperopia and clinically significant depression (CSD) in middle-aged and older individuals. The effect of genetic determinants of hyperopia on incident CSD was also explored.

METHODS

We included participants who had available data on mean spherical equivalent (MSE) and were free of depression at baseline from the UK Biobank. For the phenotypic association, hyperopia was defined as MSE of+2.00 dioptres (D) or greater, and was divided into mild, moderate and high groups. Diagnosis of CSD across follow-up was determined based on electronic hospital inpatients records. For the genetic association analysis, the association between hyperopia Polygenic Risk Score and incident CSD was assessed. Mendelian randomisation was assessed for causality association.

RESULTS

Over a median follow-up of 11.11 years (IQR: 10.92-11.38), hyperopia was significantly associated with incident CSD independent of genetic risk (HR 1.29, 95% CI 1.05 to 1.59) compared with emmetropia participants, especially in those hyperopic patients without optical correction (HR 1.38, 95% CI 1.07 to 1.76). In addition, participants in the high degree of hyperopia were more likely to have incident CSD than participants in the mild degree of hyperopia (P for trend=0.009). Genetic analyses did not show any significant associations between hyperopia and incident CSD (p≥0.1).

CONCLUSIONS

Hyperopia was significantly associated with an increased risk of incident CSD. This was independent of genetic predisposition to hyperopia, emphasising the importance of regular vision screening and correction of hyperopia to reduce the risk of CSD regardless of genetic risk.

Effect of red-light therapy on retinal and choroidal blood perfusion in myopic children

OBJECTIVE

To investigate the effect of repeated low-level red-light therapy (RLRLT) on retinal and choroidal blood perfusion in myopic children.

METHODS

Forty-seven myopic children (mean spherical equivalent refractive error [SE]: -2.31 ± 1.26 D; age range: 8.0-11.0 years) were enrolled and received RLRLT (power 2 mW, wavelength 650 nm) for 3 min twice a day, while 20 myopic children (SE: -2.75 ± 0.84 D; age range: 7.0-10.0 years) were included as a control group. All participants wore single-vision distance glasses. Refractive error, axial length (AL) and other biometric parameters were measured at baseline and during follow-up visits in the first, second and fourth weeks after initiation of treatment. Retinal thickness, subfoveal choroidal thickness (SFCT), total choroidal area (TCA), luminal area (LA), stromal area (SA) and choroidal vascularity index (CVI) were obtained using optical coherence tomography (OCT). The percentage retinal vascular density (VD%) and choriocapillaris flow voids (FV%) were measured using en-face OCT angiography.

RESULTS

After 4 weeks of treatment, a significant increase in SFCT was observed in the RLRLT group, with an average increase of 14.5 μm (95% confidence interval [CI]: 9.6-19.5 μm), compared with a decrease of -1.7 μm (95% CI: -9.1 to 5.7 μm) in the control group (p < 0.0001). However, no significant changes in retinal thickness or VD% were observed in either group (all p > 0.05). In the OCT images from the RLRLT group, no abnormal retinal morphology related to photodamage was observed. The horizontal scans revealed an increase in TCA, LA and CVI over time (all p < 0.05), while SA and FV% remained unchanged (both p > 0.05).

CONCLUSIONS

These findings indicate that RLRLT can enhance choroidal blood perfusion in myopic children, demonstrating a cumulative effect over time.

Indoor and outdoor human behavior and myopia: an objective and dynamic study

Significance

Myopia holds significant public health concern given its social, ocular disease and economic burdens. Although environmental factors are primarily to blame for the rapid rise in prevalence, key risk factors remain unresolved.

Purpose

The aim of this study was to objectively characterize, using a wearable technology, the temporal indoor and outdoor behavioral patterns and associated environmental lighting characteristics of young myopic and nonmyopic University students.

Methods

Participants were recruited to continuously wear an Actiwatch for 3 weeks, during either or both academic and non-academic periods. The device allows continuous recording of activity and incident light. Recorded illuminance levels were used as a proxy for outdoors (>1,000 lux), with the dynamics (interval frequency and duration) of indoor and outdoor activities, as well as lighting characteristics derived. In addition, participant input regarding near work was obtained daily. Participants were classified by both myopia and axial length status (based on collected refractive error and biometry data) for the purpose of data analysis.

Result

A total of 55 students, aged 18 to 25 years of age, participated. Overall, the dosing of indoor and outdoor activities was similar across participants, regardless of myopia status, during the academic period. Nonetheless, an apparent difference in the timing of outdoor activities was noted with myopes going outdoors later in the day, particularly during the weekend (p = 0.03). While a trend was observed between increased lighting levels experienced outdoors and shorter axial lengths, there was no significant relationship with myopia status. Noteworthy, participants generally significantly overestimated time spent outdoors, compared to Actiwatch-derived estimates of the same.

Conclusion

While the findings from this cohort of young adult students did not reveal substantial myopia-related differences in behavior, the power of a more objective and dynamic approach to quantifying behavior cannot be understated, providing argument for general adoption of wearable technologies in future clinical myopia studies.

Orthokeratology vs. orthokeratology combined with atropine for the control of myopia in children: systematic review

The purpose of this investigation is to determine the efficacy of orthokeratology (OK) compared to orthokeratology combined with atropine (AOK) for the control of myopia in children. A systematic review that included systematic reviews with meta-analyses, as well as randomized and controlled clinical trials, was carried out in the PubMed, Web of Science, Scopus, Cochrane Library, ProQuest, Taylor & Francis, Science Direct databases, as well as a manual search. Of the Q1-Q4 journals of the Scimago Journal & Country Rank, published in the last 5 years in English and Spanish. Eighteen studies that met the eligibility criteria were considered. The articles selected included 6,866 patients for analysis, where orthokeratology combined with 0.01% atropine was found to be more effective due to its ability to reduce the progression of myopia and axial elongation. In our investigation, it was determined that there could be an additive effect in the combination of 0.01% atropine with orthokeratology in a period of 1-2 years of treatment in patients with mild myopia; however, more multiethnic studies should be carried out, in where a correct evaluation of the progression of myopia, genetic and environmental factors that may influence the results is considered.

Lipid nanoparticles for gene therapy in ocular diseases

OBJECTIVES

Lipid nanoparticles, as a nucleic acid delivery system, have been used as an alternative to treat ocular diseases, since they can cross the ocular barrier and efficiently transfecting nucleic acids to various cells of the eye. The size influences the transfection of genes, biological distribution, diffusion, and cellular uptake. It is therefore important to establish a relationship between size, formulation, and encapsulation percentage.

EVIDENCE ACQUISITION

In this review, we used a search strategy to compare studies of nanomedicine systems aimed at eye diseases where the size of the nanoparticles and the efficiency of encapsulation of genetic material are reported based on the criteria of Preferred Reporting Items for Systematic Reviews (PRISMA ScR 2020 guidelines).

RESULTS

Out of the initial 5932, 169 studies met the inclusion criteria and were included to form the basis of the analysis. Nanoparticles reported are composed mainly of PEG-modified lipids, cholesterol, and cationic lipids, that in combination with messenger or interference RNA, allow the formulation of a nanoparticle with an encapsulation efficiency greater than 95%. The diseases treated mainly focus on conditions related to the retina and cornea. Certain characteristics of nanoparticles increase encapsulation efficiency, such as the size of the nanoparticle and the charge of the outer layer of the nanoparticle.

CONCLUSION

It is still unknown what characteristics lipid nanoparticles should have to successfully treat human eye illnesses. The in vitro and in vivo investigations covered in this review, however, present encouraging results. To improve encapsulation effectiveness and disease gene silencing, nanoparticle formulation is essential. The most stable nanoparticles are those made mostly of cationic lipids, PEG lipids, and cholesterol, which also effectively encapsulate RNA. The encapsulation efficiency is not only influenced by size, but also by other factors such as methods of preparation.

Dietary Patterns and Associations with Myopia in Chinese Children

Dietary shifts in populations undergoing rapid economic transitions have been proposed as partly contributing toward the rapid intergenerational rise in myopia prevalence; however, empirical evidence of the effect of dietary factors on myopia is limited. This study investigated the association between dietary factors and incident myopia in Chinese children aged 10-11 years. We evaluated dietary habits using a 72-item food frequency questionnaire (FFQ) among 7423 children. Myopic status was assessed using the "General Personal Information Questionnaire". Principal component analysis was used to extract dietary patterns and investigate their association with myopia. After adjusting for potential confounders, participants with the highest adherence to dietary pattern A (95% confidence interval (CI): 0.66-0.92, p for trend = 0.007) and dietary pattern C (95% CI: 0.58-0.80, p for trend < 0.001) had a lower risk of myopia than participants with the least adherence. Both of these dietary patterns are characterized by high consumption of meats, aquatic product, dairy and its products, eggs, legumes, vegetables, fruits, grains, and potatoes. Our findings suggest that other environmental factors, such as those related to the dietary environment, may contribute to the development of myopia. These findings can serve as a reference for diet-related primary prevention of myopia.

Modeling the enigma of complex disease etiology

BACKGROUND

Complex diseases often present as a diagnosis riddle, further complicated by the combination of multiple phenotypes and diseases as features of other diseases. With the aim of enhancing the determination of key etiological factors, we developed and tested a complex disease model that encompasses diverse factors that in combination result in complex diseases. This model was developed to address the challenges of classifying complex diseases given the evolving nature of understanding of disease and interaction and contributions of genetic, environmental, and social factors.

METHODS

Here we present a new approach for modeling complex diseases that integrates the multiple contributing genetic, epigenetic, environmental, host and social pathogenic effects causing disease. The model was developed to provide a guide for capturing diverse mechanisms of complex diseases. Assessment of disease drivers for asthma, diabetes and fetal alcohol syndrome tested the model.

RESULTS

We provide a detailed rationale for a model representing the classification of complex disease using three test conditions of asthma, diabetes and fetal alcohol syndrome. Model assessment resulted in the reassessment of the three complex disease classifications and identified driving factors, thus improving the model. The model is robust and flexible to capture new information as the understanding of complex disease improves.

CONCLUSIONS

The Human Disease Ontology's Complex Disease model offers a mechanism for defining more accurate disease classification as a tool for more precise clinical diagnosis. This broader representation of complex disease, therefore, has implications for clinicians and researchers who are tasked with creating evidence-based and consensus-based recommendations and for public health tracking of complex disease. The new model facilitates the comparison of etiological factors between complex, common and rare diseases and is available at the Human Disease Ontology website.

Baseline characteristics in the Israel refraction, environment, and devices (iREAD) study

The purpose of this study is to present baseline data from a longitudinal study assessing behavioral factors in three groups of boys in Israel with varying myopia prevalence. Ultra-Orthodox (N = 57), religious (N = 67), and secular (N = 44) Jewish boys (age 8.6 ± 1.4 years) underwent cycloplegic autorefraction and axial-length measurement. Time-outdoors and physical-activity were assessed objectively using an Actiwatch. Ocular history, educational factors, and near-work were assessed with a questionnaire. Group effects were tested and mixed effects logistic and linear regression were used to evaluate behaviors and their relationship to myopia. The prevalence of myopia (≤ - 0.50D) varied by group (ultra-Orthodox: 46%, religious: 25%, secular: 20%, P < 0.021). Refraction was more myopic in the ultra-Orthodox group (P = 0.001). Ultra-Orthodox boys learned to read at a younger age (P < 0.001), spent more hours in school (P < 0.001), spent less time using electronic devices (P < 0.001), and on weekdays, spent less time outdoors (P = 0.02). Increased hours in school (OR 1.70) and near-work (OR 1.22), increased the odds of myopia. Being ultra-Orthodox (P < 0.05) and increased near-work (P = 0.007) were associated with a more negative refraction. Several factors were associated with the prevalence and degree of myopia in young boys in Israel, including being ultra-Orthodox, learning to read at a younger age, and spending more hours in school.

Effects of Greenness on Myopia Risk and School-Level Myopia Prevalence Among High School-Aged Adolescents: Cross-sectional Study

BACKGROUND

Myopia is a serious public health issue. High school-aged adolescents in Beijing have an alarming prevalence of myopia. Therefore, determining myopia protective factors is essential. Green space has a certain association with myopia protective factors that can protect against myopia.

OBJECTIVE

This study aims to examine the effects of green space around schools on individual myopia risk in high school-aged adolescents and the school-level myopia prevalence.

METHODS

Green space was measured using the normalized difference vegetation index (NDVI). A total of 13,380 samples of 51 high schools were selected from a 2021 Beijing Municipal Health Commission survey. Adolescent myopia was defined as a spherical equivalent of ≤-1.00 diopters in the worse eye. Generalized linear mixed models with a binomial error structure were used to analyze the effects of the NDVI on personal myopia risk and adjust them by other factors, such as demographics, exposure time, and outdoor exercise. The effects of the NDVI on school-level myopia prevalence with adjusted demographics and the relative position factors of trees were analyzed through quasibinomial regression.

RESULTS

The overall prevalence of myopia was 80.61% (10,785/13,380, 95% CI 79.93%-81.27%). Although with a 0.1 increase in the 500 and 1000 m buffer NDVIs adjusted by demographic and other factors, the high school-aged personal myopia risk significantly dropped by 16% (odds ratio [OR] 0.84, 95% CI 0.73-0.97) and 12% (OR 0.88, 95% CI 0.79-0.99), respectively. However, only the adjusted 500 m buffer NDVI (by demographics and the position of trees) with a 0.1 increase significantly reduced the school-level myopia prevalence by 15% (OR 0.85, 95% CI 0.74-0.98). Subgroup analysis showed that the adjusted effects of the 500 m buffer NDVI are significant in schoolgirls (OR 0.82, 95% CI 0.72-0.93), juniors (OR 0.82, 95% CI 0.72-0.94), the Han nationality (OR 0.84, 95% CI 0.72-0.97), 1-year exposure (OR 0.84, 95% CI 0.71-0.99) and 3-year exposure (OR 0.78, 95% CI 0.65-0.94).

CONCLUSIONS

The greenness of a 500 m buffer around schools is associated with a lower personal myopia risk among adolescents and a lower prevalence of myopia in schools. With regard to prevention and control activities, green space within a 500 m buffer around schools is suggested as an independent protective factor for adolescent myopia.

Prevalence and Risk Factors of Refractive Errors and Effective Spectacle Coverage in Emiratis and Non-Emiratis Aged 40 Years or Older: the Dubai Eye Health Survey

PURPOSE

The aim was to investigate the prevalence and risk factors of refractive errors (REs) and the effective spectacle coverage in Emiratis and non-Emiratis in Dubai.

DESIGN

The Dubai Eye Health Survey was a population-based cross-sectional study of participants aged 40 years or older.

METHODS

Distance and near visual acuity (VA), and noncycloplegic automated refraction were tested according to a standardized protocol. Distance VA was tested using the Early Treatment Diabetic Retinopathy Study (ETDRS) logMAR chart at 3 m and near VA was measured using the near vision logMAR chart at 40 cm under ambient lighting. Myopia was defined as spherical equivalent of refraction of less than -0.50 diopters (D), and hypermetropia as spherical equivalent of more than +0.50 D. Astigmatism was defined as cylinder power of 0.5 D or greater. Effective spectacle coverage for distance vision was computed as met need/(met need+unmet need+under-met need)×100%. Multivariable logistic regression models were used to examine associations between sociodemographic factors and RE.

RESULTS

The authors included 892 participants (446 Emiratis and 446 non-Emiratis) in the analysis. The prevalence of hypermetropia was 20.4% [95% confidence interval (CI): 16.8%-24.4%] in Emiratis and 20.6% (95% CI: 20.0%-24.7%) in non-Emiratis. The prevalence of myopia and high myopia was 27.4% (95% CI: 23.3%-31.7%) and 1.8% (95% CI: 0.8%-3.5%) in Emiratis, and 19.5% (95% CI: 15.9%-23.5%) and 0.9% (95% CI: 0.2%-2.3%) in non-Emiratis, respectively. High education (P=0.02) and not currently working (P=0.002) were risk factors of myopia in non-Emiratis only. The prevalence of astigmatism was 7.4% (95% CI: 5.1%-10.2%) in Emiratis and 1.6% (95% CI: 0.6%-3.2%) in non-Emiratis. This prevalence was higher in individuals aged over 60 years (P<0.001) and men (P=0.014) among Emiratis. The prevalence of anisometropia and uncorrected presbyopia was 11.4% (95% CI: 8.6%-14.8%) and 0.7% (95% CI: 0.1%-2.0%) in Emiratis, and 9.2% (95% CI: 6.7%-12.3%) and 0.4% (95% CI: 0.05%-1.6%) in non-Emiratis, respectively. The effective spectacle coverage was 62.3% (95% CI: 54.0%-70.6%) and 69% (95% CI: 60.5%-77.5%) in Emiratis and non-Emiratis, respectively.

CONCLUSIONS

A high proportion of Emiratis and non-Emiratis was affected by RE without optimal effective spectacle coverage, highlighting the imperativeness of intervention to alleviate the burden. The findings may help facilitate evidence-based policymaking concerning the delivery of eye care services and allocation of medical resources in Dubai.

Effect of 0.02% and 0.01% atropine on ocular biometrics: A two-year clinical trial

BACKGROUND

Several studies have shown that various concentrations of low-concentration atropine can reduce myopia progression and control axial elongation safely and efficiently in children. The aim of this study was to evaluate the effects of 0.02% and 0.01% atropine on ocular biometrics.

METHODS

Cohort study. 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes nightly. Controls (N = 120) wore only SV spectacles. Ocular and corneal astigmatism were calculated using Thibos vector analysis and split into J0 and J45.

RESULTS

The changes in cycloplegic spherical equivalent refraction (SER) and axial length (AL) were -0.81 ± 0.52D, -0.94 ± 0.59D, and -1.33 ± 0.72D; and 0.62 ± 0.29 mm, 0.72 ± 0.31 mm, and 0.89 ± 0.35 mm in the 0.02% and 0.01% atropine and control groups, respectively (all P < 0.05). Both anterior chamber depth (ACD) and ocular astigmatism (including J0) increased, and lens power decreased in the three groups (all P < 0.05). However, there were no differences in the changes in ACD, ocular astigmatism, and lens power among the three groups (all P > 0.05). Intraocular pressure (IOP), corneal curvature, ocular astigmatism J45, and corneal astigmatism (including J0 and J45) remained stable over time in the three groups (all P > 0.05). The contributions to SER progression from the changes in AL, lens and corneal power of the three groups were similar (P > 0.05). The contribution of AL change alone to the change in SER was 56.3%, 63.4% and 78.2% in the above corresponding three groups.

CONCLUSIONS

After 2 years, 0.02% and 0.01% atropine had no clinical effects on corneal and lens power, ocular and corneal astigmatism, ACD or IOP compared to the control group. 0.02% and 0.01% atropine helped to control myopia progression mainly by reducing AL elongation.

Ethnic Disparities in Risk Factors for Myopia among Han and Minority Schoolchildren in Shawan, Xinjiang, China

SIGNIFICANCE

The ethnic differences in myopia rates, ocular dimensions, and risk factors between Han and non-Han schoolchildren observed in this study may help fill the knowledge gap about ethnic minorities and are important for China and other countries to address vision-related health inequalities among different ethnic groups.

PURPOSE

This study aimed to investigate the risk factors of juvenile myopia and elucidate the disparities of risk factors among Han and non-Han school students in Xinjiang, China.

METHODS

A population-based cross-sectional study of 876 schoolchildren from grades 1 to 9 was conducted in the Anjihai Middle School in Shawan, Xinjiang Uygur Autonomous Region, China. Visual acuity and ocular biometry were assessed, and personal information, including behavior, birth status, and familial factors, was collected using self-made standardized questionnaires.

RESULTS

The myopia rate among students of Han ethnicity (50.5%) was the highest, followed by Hui (41.3%) and Uygur et al. (32.0%, P < .001). Similar patterns were observed for mean axial length. The mean axial lengths are 23.7, 23.4, and 23.3 mm, respectively ( P = .01). Overall, performing high-quality eye exercises, longer sleep duration, being born in summer, parental smoking, and consuming more food containing anthocyanins were all associated with a lower incidence of myopia. Meanwhile, Han ethnicity, intensive near task, bad eye habits, and myopic mothers were associated with higher odds of myopia. After adjusting for environmental influences pertaining to myopia, the variation in myopia prevalence between Han and Uygur et al. remained significant, whereas it changed to not significant between Han and Hui ethnicities.

CONCLUSIONS

Significant disparities were found in the prevalence of myopia among various ethnic groups in Shawan, Xinjiang. Life habits, birth status, and familial factors may contribute to such variance and play different roles in the occurrence of juvenile myopia among various ethnicities.

Identification of ocular refraction based on deep learning algorithm as a novel retinoscopy method

BACKGROUND

The evaluation of refraction is indispensable in ophthalmic clinics, generally requiring a refractor or retinoscopy under cycloplegia. Retinal fundus photographs (RFPs) supply a wealth of information related to the human eye and might provide a promising approach that is more convenient and objective. Here, we aimed to develop and validate a fusion model-based deep learning system (FMDLS) to identify ocular refraction via RFPs and compare with the cycloplegic refraction. In this population-based comparative study, we retrospectively collected 11,973 RFPs from May 1, 2020 to November 20, 2021. The performance of the regression models for sphere and cylinder was evaluated using mean absolute error (MAE). The accuracy, sensitivity, specificity, area under the receiver operating characteristic curve, and F1-score were used to evaluate the classification model of the cylinder axis.

RESULTS

Overall, 7873 RFPs were retained for analysis. For sphere and cylinder, the MAE values between the FMDLS and cycloplegic refraction were 0.50 D and 0.31 D, representing an increase of 29.41% and 26.67%, respectively, when compared with the single models. The correlation coefficients (r) were 0.949 and 0.807, respectively. For axis analysis, the accuracy, specificity, sensitivity, and area under the curve value of the classification model were 0.89, 0.941, 0.882, and 0.814, respectively, and the F1-score was 0.88.

CONCLUSIONS

The FMDLS successfully identified the ocular refraction in sphere, cylinder, and axis, and showed good agreement with the cycloplegic refraction. The RFPs can provide not only comprehensive fundus information but also the refractive state of the eye, highlighting their potential clinical value.

Choroidal Thickness in a Hyperopic Pediatric Population

Aims: To evaluate the choroidal thickness (CT) in hyperopic and emmetropic children using swept-source optical coherence tomography (SS-OCT). Methods: This was a prospective, cross-sectional comparative study. Macular choroidal thickness and axial length of 62 eyes from hyperopic pediatric patients were studied. CT was determined at nine different macular locations. The results were compared to 66 eyes of healthy pediatric patients. Results: Study groups were classified as a hyperopic group (SE ≥ 2D) and an emmetropic group (SE < 2D). The hyperopic group have shorter AL than the emmetropic group (p < 0.001). The mean CT is greater in the hyperopic group (p = 0.039), and there are no significant differences between CT and gender (p = 0.389). Study participants were also classified by age (2−5 years old and 6−18 years old), and we observe differences in CT, but these differences are only significant for the 6−18 years old group (p < 0.05). Conclusions: CT in hyperopic pediatric populations is statistically thicker than in healthy pediatric patients. AL and SE have statistically significant correlations with CT values, and those correlations are seen in children in the ocular slow-growing phase (6−18 years old), and not in the early years (2−5 years old).

Spectrum of ophthalmic diseases in children hospitalized in a tertiary ophthalmology hospital in China from 2010 to 2019

BACKGROUND

Describing the pattern of pediatric eye diseases is necessary for appropriate eye care in children. This study explored the spectrum and characteristics of pediatric ophthalmic diseases in a typical tertiary ophthalmology hospital in China.

METHODS

A retrospective study was conducted at a tertiary ophthalmology hospital between 2010 and 2019 in Guangzhou, China. This study included 44,552 inpatients who were younger than 18 years old. Demographic and diagnostic data were collected from the electronic medical record system. Multiphase regression analysis was used to estimate trends in the annual percentages of ten common ophthalmic diseases.

RESULTS

From 2010 to 2019, 44,552 inpatients met the inclusion criteria. The majority were male (61.9%), aged 7 to 12 years (30.3%) and self-paying (56.6%). The top ten conditions were refractive error (41.2%), strabismus (36.1%), cataract (13.6%), trauma (11.8%), congenital ptosis (8.8%), tumor (8.1%), amblyopia (7.1%), glaucoma (7.0%), entropion and trichiasis of eyelid (7.0%), and retinal detachment (6.5%). The annual percentage changes (APCs) for refractive error, strabismus, and retinal detachment were 9.3% (95% CI, 8.1-10.5%), 4.7% (95% CI, 3.8-5.6%) and - 2.8% (95% CI, - 5.1% to - 0.4%) respectively. For trauma, the average APC (AAPC = -9.2%, (95% CI, - 12.1% to - 6.2%) decreased gradually from 2010 to 2015 (APC = -4.2% (95% CI, - 8.8-0.7%)) and decreased rapidly from 2015 to 2019 (APC = -15.1% (95% CI, - 21.0% to - 8.7%)).

CONCLUSIONS

Pediatric ophthalmic diseases are common in China. Preventive strategies and health education aimed at the prevention of refractive error, strabismus, and entropion and trichiasis of eyelid will be crucial in reducing the burden of pediatric ophthalmic diseases on health care systems and human development.

Association of Physical Activity and Sedentary Behaviors with the Risk of Refractive Error in Chinese Urban/Rural Boys and Girls

Background: Research shows physical activity (PA) is negatively associated with refractive error, especially outdoor activity. Our study aimed to examine the association of PA levels and sedentary time (SED) with refractive error in boys and girls living in urban and rural areas. Methods: A total of 8506 urban/rural boys and girls (13.5 ± 2.8 years old) in Shaanxi Province, China participated in this study. Questions about PA, SED, outdoor exercises, and digital screen time were asked in the study survey. Non-cycloplegic refractive error was measured by an autorefractor. The differences between sex/area groups have been analyzed by one-way ANOVA. The association of PA/SED with spherical equivalent (SE) and cylinder power was analyzed by general linear regression. The association between PA/SED and the risk of refractive error was determined using the binary logistic regression model. Results: Of the 8506 participants, the prevalence of refractive error was significantly higher in girls and urban students (p < 0.05). Less SED and digital screen time, and more outdoor activity were significantly associated with SE (p < 0.05), respectively. More PA and less SED were significantly associated with lower cylinder power (p < 0.05), respectively. More PA and less SED were significantly associated with lower risks of myopia and astigmatism, respectively (p < 0.05). Conclusions: PA and SED were associated with the risk of refractive error. Maintaining a healthy lifestyle can help to reduce the risk of refractive error in boys and girls.

Effect of 0.02% and 0.01% atropine on astigmatism: a two-year clinical trial

Background

To evaluate the effects of 0.02% and 0.01% atropine eye drops on ocular and corneal astigmatism over 2 years.

Methods

A prospective clinic-controlled trail. The cohort study assessed 400 myopic children and divided them into three groups: 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes once nightly. Control children (n = 120) only wore SV spectacles. Spherical equivalent refractive errors (SER) and corneal curvature were measured every 4 months. The SER and corneal curvature were assessed by cycloplegic autorefraction and IOLMaster. Ocular and corneal astigmatism were calculated by Thibos vector analysis and then split into its power vector components, J0 (with-the-rule astigmatism) and J45 (oblique).

Results

After 2 years, the ocular astigmatism increased by -0.38 ± 0.29 D, -0.47 ± 0.38 D, -0.41 ± 0.35 D in the 0.02%, 0.01% atropine groups and control group, respectively (p = 0.15). The corresponding corneal astigmatism increased by -0.20 ± 0.34 D, -0.28 ± 0.35 D and -0.26 ± 0.26 D (p = 0.18). The ocular astigmatism J0 increased by 0.19 ± 0.28 D, 0.22 ± 0.36 D, 0.18 ± 0.31 D in the 0.02% atropine, 0.01% atropine and control groups, respectively (p = 0.65). The corresponding corneal astigmatism J0 increased by -0.05 ± 0.34 D, -0.11 ± 0.37 D and -0.13 ± 0.30 D (p = 0.23). There was a small but significant increase in ocular astigmatism (including J0) (all P < 0.05), but there were no changes in the ocular astigmatism J45 and corneal astigmatism (including J0 and J45) in the three groups over time (all p > 0.05). However, there were no significant differences in the changes in ocular astigmatism (including J0) among the three groups.

Conclusions

Treatment with 0.02% and 0.01% atropine had no clinically significant effect on ocular and corneal astigmatism over 2 years.

Trial registration

The First Affiliated Hospital of Zhengzhou University, ChiCTR-IPD-16008844. Registered 14/07/2016.

Prevalence of and factors associated with astigmatism in preschool children in Wuxi City, China

PURPOSE

To investigate the status of astigmatism in preschool children in Wuxi City, and explore the risk factors related to astigmatism. The risk factors related to astigmatism development as predictors can help us identify preschool children who need vision screening at an early stage to ensure good visual quality.

METHODS

The cross-sectional study was conducted in 10 kindergartens randomly selected in five districts of Wuxi City in November 2018. All preschool children were measured by objective refractometry under non-cycloplegic refraction. The basic information of preschool children was collected. The relevant factors of astigmatism in the questionnaire were completed by parents. Spss 26. 0 software was used for univariate and multivariate correlation analysis.

RESULTS

A total of 889 preschool children participated in the study, 864 were finally included in the study. The prevalence of astigmatism was 36.0%. The risk of astigmatism in premature children was higher than that in non-premature children (adjusted odds ratio = 1.841). The prevalence of astigmatism with parents' astigmatism history was higher, compared with preschool children without parents' astigmatism history (adjusted odds ratio = 2.037). When maternal age at childbirth was older (≥ 35 years old), the risk of astigmatism increased in preschool children (adjusted odds ratio = 2.181). Compared with bottle feeding, the risk of astigmatism for mixed feeding and breastfeeding reduced in preschool children. Compared with preschool children exposed to electronic screen for less than 2 h every day, preschool children exposed to electronic screen for more than 2 h had an increased risk of astigmatism (P = 0.004).

CONCLUSION

The prevalence of astigmatism among preschool children in Wuxi City was high. Some risk factors such as premature birth, parents' astigmatism history, maternal age at childbirth, feeding pattern, and electronic screen exposure time were closely related to the occurrence of astigmatism among preschool children. For preschool children with significant risk factors, their eyesight should be checked regularly to ensure their visual quality.

Measurements of Tear Evaporation Rate in Subjects with Refractive Errors Using a Portable Evaporimeter

Dry eye symptoms are associated with refractive errors. We aimed to measure the tear evaporation rate (TER) in subjects with refractive errors (RE) using a portable evaporimeter. This nonrandomized, case–control, and observational study included 75 subjects, including 25 subjects aged 18–38 years (28.8 ± 6.8 years) with myopia (−0.75 to −3.75 D) and 25 subjects aged 18–39 years (27.7 ± 5.5 years) with hyperopia (+0.50 to +3.75 D). In addition, a control group of 25 subjects with emmetropic eyes aged 20–30 years (23.6 ± 2.6 years) was recruited. The ocular surface disease index (OSDI) was completed, followed by the TER measurements using a portable evaporimeter. The OSDI score and TER measurements showed dry eye symptoms in 36% and 48% of myopic subjects, respectively. For hyperopic participants, dry eye was observed in 24% and 56% of the subjects based on the OSDI and TER scores, respectively. Significant differences (Mann-Whitney U test; p < 0.001) were found among the OSDI and TER scores recorded within the study (myopic and hyperopic subjects) and control groups. Significant strong positive correlations were detected between the OSDI and TER scores in both myopic (p = 0.004; r = 0.559) and hyperopic (p = 0.001; r = 0.619) subjects. The TER scores were significantly higher in subjects with RE (myopic and hyperopic) as compared with individuals with normal eyes.

Distribution, Progression, and Associated Factors of Refractive status of Children in Lhasa, Tibet after COVID-19 Quarantine

Introduction Uncorrected refractive error is one of the major causes of visual impairment in children and adolescents worldwide. During the COVID-19(Coronavirus Disease 2019) epidemic,home isolation is considered a boost to the progression of children's myopia. Under geographical conditions of high altitude and strong sunshine, the Tibetan plateau is the main residence of the Tibetan population, where little information is available about the refractive status and developmental trajectory.Therefore,this article aimed to evaluate the distribution,progression,and associated factors of the refractive status in second grade children in Lhasa after COVID-19 quarantine. Materials and Methods Students from 7 elementary schools completed comprehensive ocular examinations in the Lhasa Childhood Eye Study. Data regarding cycloplegic refraction and corneal biometry parameters, including axial length (AL),corneal power,anterior chamber depth(ACD),and other demographic factors,were analyzed. Results A total of 1,819 students were included, with a mean age of 7.9±0.5 years, of which 961 were boys (52.8%), and 95.1% were Tibetan. The prevalence of myopia, emmetropia, mild hyperopia and hyperopia was 10.94%, 24.02%, 60.80% and 4.24%, respectively. Besides, the average cycloplegic spherical equivalent refraction(SER) was +1.07±0.92D before the COVID-19 quarantine and +0.59±1.08D after the quarantine, with a growth rate of 7%. Moreover, the prevalence of hyperopia in girls was significantly higher than that of boys. Nonetheless, the proportion of myopia and emmetropia was similar. Meanwhile, children in suburban schools had a significantly lower proportion of myopia. The average AL, ACD, lens power (LP) and axial length-to-corneal radius(AL/CR) ratio were 22.79±0.78mm, 3.54±0.21mm, 25.12±1.48D and 2.93±0.08, respectively. The result of AL,ACD,and AL/CR for girls were significantly lower than for boys while the result of LP is the opposite. Finally, multivariate regression analysis revealed that SER was negatively correlated with AL, LP, and AL-to-CR ratio, while positively correlated with CR and ACD. Conclusion This study found that after the COVID-19 confinement, myopia progressed faster in Lhasa children but was still significantly lower than that of plain cities in China. Compared to short-term confinement, this acceleration was more likely related to the growth and general trend of myopia in children. Collectively, these findings help to explore the differences in ocular growth and development among children of different ethnic groups.

Correlation Between Increase of Axial Length and Height Growth in Chinese School-Age Children

Purpose

To identify the relationship between the increase in axial length (AL) and height in school-age children and explore the influence of refractive status on such a relationship.

Methods

In this 5-year cohort study, 414 Chinese children (237 boys) aged 6–9 years (mean 7.12) underwent measurements annually. AL was measured using the Lenstar; height with the children standing, without shoes; and refraction using subjective refraction without cycloplegia. Participants were divided according to the refractive status: persistent emmetropia, persistent myopia, and newly developed myopia. The measurement time points of the persistent emmetropia and persistent myopia groups were marked as T₁, T₂, T₃, T₄, and T₅. The time of myopia onset in the newly developed myopia group was marked as t₀; the preceding time points were marked as t₋₁, t₋₂, and so on, and the succeeding as t₁, t₂, and so on. The association between increase in AL and height was analyzed using simple correlation analysis.

Results

The mean changes in AL, height, and refraction were 1.39 mm, 23.60 cm, and −1.69 D, respectively, over 5 years in all children. The increase in AL and height were positively correlated for T₁~T₂, T₁~T₃, T₁~T₄, and T₁~T₅ (r = 0.262, P < 0.001; r = 0.108, P = 0.034; r = 0.165, P = 0.001; r = 0.174, P = 0.001, respectively). The changes in AL and height in the newly developed myopia group were significantly correlated (r = 0.289, P = 0.009) after myopia onset (t₀~t₂).

Conclusion

The increase in AL and height were positively correlated, especially in the newly developed myopia group after myopia onset. Thus, when children grow quickly, AL elongation should be monitored.

Ocular findings in 22q11.2 deletion syndrome: A systematic literature review and results of a Dutch multicenter study

The 22q11.2 deletion syndrome (22q11.2DS) is a multisystem disorder with an estimated prevalence of 1:3000 live births. Manifestations show a marked variability in expression and include speech‐ and language delay, intellectual disability, and neuropsychiatric disorders. We aim to provide an overview of ocular findings in 22q11.2DS in order to optimize recommendations for ophthalmic screening. We combined results from a systematic literature review with results from a multicenter cross‐sectional study of patients with 22q11.2DS who were assessed by an ophthalmologist. Our systematic literature search yielded four articles, describing 270 patients. We included 132 patients in our cross‐sectional study (median age 8.9 [range 0–56] years). Most reported ocular findings were retinal vascular tortuosity (32%–78%), posterior embryotoxon (22%–50%), eye lid hooding (20%–67%), strabismus (12%–36%), amblyopia (2%–11%), ptosis (4%–6%), and refractive errors, of which hyperopia (6%–48%) and astigmatism (3%–23%) were most common. Visual acuity was (near) normal in most patients (91%–94%). Refractive errors, strabismus, and amblyopia are treatable conditions that are frequently present in patients with 22q11.2DS and should be corrected at an early stage. Therefore, in 22q11.2DS, we recommend ophthalmic and orthoptic screening at the age of 3 years or at diagnosis, and a low‐threshold referral in adults.

Association of maternal diabetes during pregnancy with high refractive error in offspring: a nationwide population-based cohort study

AIMS/HYPOTHESIS

We aimed to investigate the associations between maternal diabetes before or during pregnancy and the risk of high refractive error (RE) in offspring until the age of 25 years.

METHODS

This nationwide register-based cohort study comprised 2,470,580 individuals born in 1977-2016. The exposure was maternal diabetes during or before pregnancy (type 1 diabetes, type 2 diabetes and gestational diabetes). Cox regression was used to examine the association between maternal diabetes and the risk of high RE in offspring from birth until the age of 25 years, adjusting for multiple potential confounders.

RESULTS

During up to 25 years of follow-up, 553 offspring of mothers with diabetes and 19,695 offspring of mothers without diabetes were diagnosed with high RE. Prenatal exposure to maternal diabetes was associated with a 39% increased risk of high RE: HR 1.39 (95% CI 1.28, 1.51), p < 0.001; standardised cumulative incidence in unexposed offspring at 25 years of age 1.18% (95% CI 1.16%, 1.19%); cumulative incidence difference 0.72% (95% CI 0.51%, 0.94%). The elevated risks were observed for hypermetropia (HR 1.37 [95% CI 1.24, 1.51], p < 0.001), myopia (HR 1.34 [95% CI 1.08, 1.66], p = 0.007) and astigmatism (HR 1.58 [95% CI 1.29, 1.92], p < 0.001). The increased risks were more pronounced among offspring of mothers with diabetic complications (HR 2.05 [95% CI 1.60, 2.64], p < 0.001), compared with those of mothers with diabetes but no diabetic complications (HR 1.18 [95% CI 1.02, 1.37], p = 0.030).

CONCLUSIONS/INTERPRETATION

Our findings suggest that maternal diabetes during pregnancy is associated with an increased risk of high RE in offspring, in particular among those of mothers with diabetic complications. Early ophthalmological screening should be recommended in offspring of mothers with diabetes diagnosed before or during pregnancy.

Global disease burden of uncorrected refractive error among adolescents from 1990 to 2019

Background

To estimate the global disease burden of uncorrected refractive error (URE) among adolescents and assess the contributions of various risk factors to disability-adjusted life-years (DALYs) due to URE.

Methods

Global, regional and country-level DALY numbers and rates due to URE among adolescents were acquired from the Global Burden of Disease Study 2019 database. Human Development Index (HDI), Socio-Demographic Index (SDI) and other country-level data were obtained from other open databases as potential indicators. Regression analysis was used to evaluate associations between DALY rates among adolescents and potential predictors.

Results

Global DALYs due to URE among adolescents rose by 8% between 1990 and 2019 but moderately decreased by 4.8% during this period after adjusting for population size. Female adolescents showed higher DALY rates. DALY rates sharply increased from 5 to 9 years of age, then rose more slowly, reaching a plateau before 20 years of age. Country-level DALY rates in 2019 were positively associated with HDI, SDI, and urbanization rates but negatively correlated with primary school dropout rates. Higher disease burden of adolescents visually impaired from URE was associated with lower primary school dropout rates (β = − 0.257, 95% CI − 0.376 to − 0.138, P < 0.001) and higher urbanization rates (β = 0.257, 95% CI 0.067 to 0.256, P = 0.001).

Conclusions

Higher socioeconomic status, urbanization rates and education levels are associated with a heavier disease burden of URE among adolescents. The findings of this study can provide a reference for policy making on resource allocation for URE prevention and control in teenagers.

The Prevalence of Visual Impairment and Refractive Errors among a Youth Population in Mozambique: Evidence of the Need for Intervention

Visual impairment (VI) can significantly interfere in the child's daily activities and quality of life, having a negative effect on their development and learning. The aim of the study was to determine the prevalence of VI and associated demographic factors in students examined during the program "Moçambique te vejo melhor". This study was cross-sectional and retrospective, based on the 2018/19 edition of the program. Eye examinations were performed in secondary school students, aged between 12 and 20 years, of five districts in Nampula province. The examination included visual acuity, non-cycloplegic refraction and assessment of the anterior and posterior segment and ocular adnexa. The prevalence of uncorrected, presenting and best-corrected VI found was 18.3%, 10.8%, and 5.0%, respectively. Refractive error (RE) had a prevalence of 24.7%, and the age groups between 15-17 years and 18-20 years were significantly associated with myopia (with OR: 4.9 and OR: 8.8, respectively), as well as the 11th and 12th grade (OR: 8.1 and OR: 10.7, respectively), and Malema district had association with myopia (ORa: 0.4) and hyperopia (ORa: 0.4 and OR: 0.3) as a protective factor. The prevalence of RE and VI was relatively high, showing the need for greater intervention at the school level.

Refractive status of patients attending eye clinics of the Public Health System from Aguascalientes, Mexico

PURPOSE

This paper aims to evaluate the prevalence of REs in a clinic from Aguascalientes, Mexico by analysing clinical records from the local public health system. Refractive errors (REs) are quite common globally, but no data have been published regarding their frequency in clinics from Mexico. A priori, the frequency of ametropias should be high as admixture ancestry from this region is mainly European and Amerindian, the regions with high prevalence worldwide.

METHODS

This cross-sectional study was conducted on 2195 subjects from records of public optometry services during the year 2018. Information obtained included age, gender, sphere, cylinder and axis. The prevalence of myopia, hyperopia and astigmatism was determined by gender and age groups in paediatric and adult patients. Chi-square testing was applied to determine significant differences in prevalence across age groups and gender. A p-value <0.05 was considered significant.

RESULTS

In subjects under 18 years of age, the prevalence of emmetropia, astigmatism, myopia and hyperopia was 20.1%, 51.1%, 7.0% and 11.8%, respectively. In adults, emmetropia was present at a frequency of 20.1%, while 57.1% presented astigmatism, 12.4% hyperopia and 8.6% presented myopia. A significant association was observed between the presence of REs and age and gender.

CONCLUSIONS

In this first report of prevalence of REs from western Mexico, astigmatism was the most prevalent RE in children, adolescents and adults while the least common was myopia. Important differences were found in prevalence in comparison to national and international reports.

Associations of refractive errors and retinal changes measured by optical coherence tomography: A systematic review and meta-analysis

Studies reporting alteration in retinal thickness using optical coherence tomography (OCT) have been performed in different populations with various degrees of refractive error, producing inconsistent results. Therefore, we performed a meta-analysis to evaluate the alterations in retinal OCT measurements in myopic and hyperopic patients compared to controls. Evaluation of different retinal layers' thickness may have significance for developing novel approaches for preventing, diagnosing, and treating refractive errors and their complications. We searched PubMed and EMBASE to identify articles that reported OCT measurements of different retinal layers and regions, including macular, foveal, parafoveal, perifoveal, foveolar, ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell and inner plexiform layer (GC-IPL) thickness in addition to macular volume, and optic disc area in myopes and hyperopes comparing their differences with controls. We applied either a fixed-effects or random-effects model for the meta-analysis of these differences based on the assessed heterogeneity level. Furthermore, subgroup analyses and metaregression, as well as publication bias and quality assessment, were conducted for the eligible studies. Forty-seven studies with a total of 12223 eyes, including 8600 cases and 3623 non-cases, are included in this meta-analysis. Our results showed that, in comparison to controls, highly myopic eyes had a significantly lower value for mean macular thickness, macular GCC, macular GC-IPL, parafoveal, perifoveal, foveal, foveolar, RNFL, and pRNFL thickness. Compared to controls, moderately myopic eyes showed a significantly thinner mean macular GCC layer and pRNFL. On the other hand, hyperopic eyes had significantly thicker average pRNFL than controls. Several other significant differences were also observed in various regional analyses. The findings of the current study affirm the retinal OCT measurement differences between myopic and hyperopic eyes compared to controls, emphasizing OCT measurements' advantages as potential biomarkers of ocular pathologies.

Association of eleven single nucleotide polymorphisms with refractive disorders from Eskisehir, Turkey

AIM

To investigate relationship between refractive errors and eleven single nucleotide polymorphisms (SNPs) in HGF, GC, MFN1, GNB4, and VDR genes in Turkish population.

METHODS

A group of 212 participants with myopia (n=91), hyperopia (n=45), and emmetropia (n=76) were investigated in this study. SNPs in HGF, GC, MFN1, GNB4 and VDR genes were studied by SnapShot technique.

RESULTS

The patients in this study consists of 47 female/44 male (age: 23.47±4.30) patients with myopia, 20 female/25 male (age: 31.20±8.02) with hyperopia and 33 female/43 male (age: 25.22±6.60) with emmetropia. The genotype distribution of the rs7618348 polymorphism, which was the only statistically significant one between myopia and emmetropia group. The genotype distribution of the rs3819545, rs3735520, rs7041, and rs2239182 polymorphisms, which were statistically significant between hyperopia and emmetropia groups.

CONCLUSION

The importance of genetic predisposition to refractive errors with respect to etiology of the disease is revealed. It is known that polymorphism studies may differ because of genetic diversity among populations so larger cohort studies are required in different populations to enlighten the etiology of the refractive errors.

Effects of blue light-exposed retinal pigment epithelial cells on the process of ametropia

Ametropia is one of the most common ocular disorders worldwide, to which almost half of visual impairments are attributed. Growing evidence has linked the development of ametropia with ambient light, including blue light, which is ubiquitous in our surroundings and has the highest photonic energy among the visible spectrum. However, the underlying mechanism of blue light-mediated ametropia remains controversial and unclear. In the present study, our data demonstrated that exposure of the retinal pigment epithelium (RPE) to blue light elevated the levels of the vital ametropia-related factor type Ⅰ collagen (COL1) via β-catenin inhibition in scleral fibroblasts, leading to axial ametropia (hyperopic shift). Herein, our study provides evidence for the vital role of blue light-induced RPE dysfunction in the process of blue light-mediated ametropia, providing intriguing insights into ametropic aetiology and pathology by proposing a link among blue light, RPE dysfunction and ametropia.