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Aim: To determine the regional and ethnic differences in ocular axial elongation and refractive error progression in myopic and non‐myopic children. Methods: A retrospective analysis of 15 longitudinal clinical and population‐based studies was conducted in the UK, Sweden, Australia (classified as European), China, and Vietnam (classified as East Asian) between 2005 and 2021. A total of 14,593 data points from 6208 participants aged 6–16 years with spherical equivalent from +6 to −6 D were analysed. Progression was annualised from longitudinal axial length and cycloplegic spherical equivalent (SE) refraction. Generalised estimating equation models including main effects and interactions were used for model building. Age and region‐specific estimates for myopes and non‐myopes and confidence intervals are reported. Results: Factors affecting axial elongation and SE progression in children included being myopic, followed by age, region/ethnicity and sex. The magnitude of regional/ethnic differences was dependent on myopia and age. Axial elongation and SE progression were lower in European compared with East Asian children, but differences were reduced with increasing age and differences in axial elongation were larger in myopes than non‐myopes. Age‐specific regional/ethnic differences indicated that axial elongation for a 6‐year‐old East Asian myopic child was greater than a European child by 0.15 mm/year (0.58 vs. 0.43 mm/year) and by 0.09 mm/year (0.35 vs. 0.26 mm/year) for a 10‐year‐old myope. SE progression was lower in a 6‐year‐old European myope by 0.48 D/year and at 10 years of age by 0.34 D/year compared with an East Asian myope. Conclusions: There are regional/ethnic differences in age‐specific refractive and axial growth patterns in both myopic and non‐myopic eyes, with more marked differences in younger East Asian children who demonstrated a higher axial growth and greater negative SE shift than their non‐Asian peers. Regional/ethnic differences in progression reflect environmental and ethnic variations. Age and region/ethnicity‐specific estimates could contribute as a reference for future comparisons. [ABSTRACT FROM AUTHOR]

Aim: To determine the influence of refractive error (RE), age, gender and parental myopia on axial elongation in Chinese children and to develop normative data for this population. Methods: This is a retrospective analysis of eight longitudinal studies conducted in China between 2007 and 2017. Data of 4701 participants aged 6–16 years with spherical equivalent from +6 to −6D contributed to one, two or three annualised progression data resulting in a dataset of 11,262 eyes of 26.6%, 14.8% and 58.6% myopes, emmetropes and hyperopes, respectively. Longitudinal data included axial length and cycloplegic spherical equivalent RE. Axial elongation was log‐transformed to develop an exponential model with generalised estimating equations including main effects and interactions. Model‐based estimates and their confidence intervals (CIs) are reported. Results: Annual axial elongation decreased significantly with increasing age, with the rate of decrease specific to the RE group. Axial elongation in myopes was higher than in emmetropes and hyperopes but these differences reduced with age (0.58, 0.45 and 0.27 mm/year at 6 years and 0.13, 0.06 and 0.05 mm/year at 15 years for myopes, emmetropes and hyperopes, respectively). The rate of elongation in incident myopes was similar to that in myopes at baseline (0.33 vs. 0.34 mm/year at 10.5 years; p = 0.32), while it was significantly lower in non‐myopes (0.20 mm/year at 10.5 years, p < 0.001). Axial elongation was greater in females than in males and in those with both parents myopic compared with one or no myopic parent, with larger differences in non‐myopes than in myopes (p < 0.01). Conclusions: Axial elongation varied with age, RE, gender and parental myopia. Estimated normative data with CIs could serve as a virtual control group. [ABSTRACT FROM AUTHOR]

To evaluate the efficacy of time outdoors per school day over 2 years on myopia onset and shift. A prospective, cluster-randomized, examiner-masked, 3-arm trial. A total of 6295 students aged 6 to 9 years from 24 primary schools in Shanghai, China, stratified and randomized by school in a 1:1:1 ratio to control (n = 2037), test I (n = 2329), or test II (n = 1929) group. An additional 40 or 80 minutes of outdoor time was allocated to each school day for test I and II groups. Children in the control group continued their habitual outdoor time. Objective monitoring of outdoor and indoor time and light intensity each day was measured with a wrist-worn wearable during the second-year follow-up. The 2-year cumulative incidence of myopia (defined as cycloplegic spherical equivalent [SE] of ≤–0.5 diopters [D] in the right eye) among the students without myopia at baseline and changes in SE and axial length (AL) after 2 years. The unadjusted 2-year cumulative incidence of myopia was 24.9%, 20.6%, and 23.8% for control, test I, and II groups, respectively. The adjusted incidence decreased by 16% (incidence risk ratio [IRR], 0.84; 95% confidence interval [CI], 0.72–0.99; P = 0.035) in test I and 11% (IRR = 0.89; 95% CI, 0.79–0.99; P = 0.041) in test II when compared with the control group. The test groups showed less myopic shift and axial elongation compared with the control group (test I: –0.84 D and 0.55 mm, test II: –0.91 D and 0.57 mm, control: –1.04 D and 0.65 mm). There was no significant difference in the adjusted incidence of myopia and myopic shift between the 2 test groups. The test groups had similar outdoor time and light intensity (test I: 127 ± 30 minutes/day and 3557 ± 970 lux/minute; test II: 127 ± 26 minutes/day and 3662 ± 803 lux/minute) but significantly more outdoor time and higher light intensity compared with the control group (106 ± 27 minutes/day and 2984 ± 806 lux/minute). Daily outdoor time of 120 to 150 minutes at 5000 lux/minutes or cumulative outdoor light intensity of 600 000 to 750 000 lux significantly reduced the IRR by 15%～ 24%. Increasing outdoor time reduced the risk of myopia onset and myopic shifts, especially in nonmyopic children. The protective effect of outdoor time was related to the duration of exposure and light intensity. The dose–response effect between test I and test II was not observed probably because of insufficient outdoor time achieved in the test groups, which suggests that proper monitoring on the compliance on outdoor intervention is critical if one wants to see the protective effect. [ABSTRACT FROM AUTHOR]

Background: It is generally believed that a 1‐mm axial length (AL) elongation of the eye corresponds to a −3.00 D spherical equivalent (SE) progression, but this is disputed. Purpose: To investigate the association between AL elongation and SE progression among children and adolescents. Methods: A prospective cohort study of 710 children and adolescents aged 6–16 years was included. Ophthalmic examinations, including cycloplegic SE, AL and corneal curvature, were performed at baseline and 1‐year follow‐up. The ratio of SE change (ΔSE) to AL change (ΔAL) (ΔSE/ΔAL) was calculated, and its association with age and refractive status was explored using a general linear model. Results: Among all participants, 396 (55.77%) were male, with 265 (37.32%) myopes at baseline. The average 1‐year ΔSE and ΔAL were 0.61 ± 0.40 D and 0.33 ± 0.22 mm, respectively. Both ΔSE and ΔAL gradually decreased with age (p < 0.001). In the general linear model analyses, age and refractive status were independently associated with ΔSE/ΔAL after adjustment for covariates (age: β̂$$ \hat{\beta} $$ = 0.04, p < 0.05; myopia vs nonmyopia: β̂$$ \hat{\beta} $$ = 0.28, p < 0.05). Based on the developed formula ΔSE/ΔAL = 1.74 + 0.05*age (for myopes), mean ΔSE/ΔAL in myopes increased from 2.06 D/mm in the 6‐year‐olds to 2.59 D/mm in the 16‐year‐olds. In nonmyopes, ΔSE/ΔAL = 1.33 + 0.05*age, and the ratio increased from 1.65 D/mm in the 6‐year‐olds to 2.18 D/mm in the 16‐year‐olds. Conclusions: The ratio of ΔSE/ΔAL varied with age and refractive status in children and adolescents. The age‐specific ΔSE/ΔAL could be used to estimate SE progression through the actual AL change. [ABSTRACT FROM AUTHOR]

Purpose: To determine the characteristics of crystalline lens with varying refractive errors and relationship with axial elongation in young school children. Methods: A total of 1465 children aged 6–8 years were examined annually for 2 years. Each participant underwent a series of ophthalmic examinations, including cycloplegic autorefraction, crystalline lens and axial length measurement. Crystalline lens power was determined, and factors associated with different refractive statuses were investigated. Results: Crystalline lens power decreased with time; reduction in lens power in Year 1 was greater in children with emmetropia (−0.69 ± 0.59 dioptre [D]) than in those with hyperopia (−0.49 ± 0.56 D) or myopia (−0.45 ± 0.55 D) (p < 0.001). Among the emmetropes, there were no differences in loss of crystalline lens power between those who remained emmetropic (−0.63 ± 0.59 D) and those who became myopic at Year 1 (−0.74 ± 0.61 D) and Year 2 (−0.77 ± 0.57 D, p > 0.05) visits. Among myopes at Year 1 visit, there was a greater reduction at Year 2 in those who had baseline emmetropia (−0.61 ± 0.51 D) than those who had baseline myopia (−0.26 ± 0.49 D, p < 0.001). The trend was similar among children of the same age. There was a significant correlation between changes in lens power and axial elongation in non‐myopia (β = −0.954, p < 0.001) and new myopia (β = −1.178, p < 0.001), but not in established myopia (β = −0.001, p = 0.539). Conclusions: There is accelerated loss of lens power in emmetropia and early stage of myopia. However, this loss is retarded when myopia persists and is accompanied by disappearance of the compensatory effect of lens power against axial elongation. These findings provide new insights into human refractive development. [ABSTRACT FROM AUTHOR]

Purpose: To describe the methodology and pilot data of the Shanghai Child and Adolescent Large‐scale Eye Study (SCALE‐HM). Methods: This is a population‐based, prospective, examiner‐masked study with annual follow‐up. Patients are 4‐ to 18‐year‐olds with high myopia. The participants will fill out questionnaires and then undergo visual acuity, axial length (AL), intraocular pressure, ophthalmologist assessment, microperimetry, cycloplegic refraction, Pentacam, wavefront aberration, fundus, blood and saliva examinations. To describe the pilot data, intergroup differences were assessed with t‐tests or analysis of variance and a logistic regression model was used to determine the independent factors associated with peripapillary atrophy (PPA). Results: Overall, 134 eyes of 79 participants met the pilot study recruitment criteria. The mean AL and spherical equivalent were 26.91 ± 1.07 mm and −9.40 ± 1.77 D, respectively. Peripapillary atrophy (PPA) (N = 112) and tessellated fundus (N = 67) were the most common fundus changes. The mean AL was significantly longer in PPA (27.08 ± 0.93 mm) than in non‐PPA eyes (26.06 ± 1.31 mm; p < 0.001). Axial length (AL) (p = 0.041) was the only independent factor associated with PPA. Axial length (AL) was significantly longer in eyes with diffuse chorioretinal atrophy (N = 11; 28.02 ± 1.31 mm) than without myopic retinal lesions (N = 56; 26.48 ± 0.91 mm, p < 0.001) or with tessellated fundus (N = 67; 27.09 ± 0.97 mm, p = 0.012). The myopic degree was higher in eyes with diffuse chorioretinal atrophy than without myopic retinal lesions (−10.51 ± 2.76 D versus −9.06 ± 1.58 D, p = 0.039). Conclusion: Peripapillary atrophy and tessellated fundus were common in children and adolescents with high myopia. Results from this prospective study will help to understand the mechanisms, development and prognosis of these changes and can guide early myopia screening. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to investigate age‐specific normative retinal oxygen saturation values and explore the associated factors in healthy Chinese school‐aged children with different refractive statuses. Design: Population‐based observational cross‐sectional study. Methods: Children aged 7–19 years were enrolled. Each participant underwent a series of comprehensive ocular examinations, including axial length (AL), cycloplegic refraction and Oxymap T1 imagery following cycloplegia. The acquired oximetry images were measured, and the values of the retinal oxygen saturation parameters were calculated. The independent factors of the retinal oxygen saturation were analysed using multiple linear regression. The oxygen saturation of retinal arteries (SaO2) and veins (SvO2) as well as the differences between the arteries and veins (AVD) were measured as the main outcomes. Results: In total, 1461 participants were included in the study. The mean age of the participants was 12.1 ± 3.2 years, and 53.0% were boys. The mean SaO2, SvO2 and AVD values were 83.7 ± 6.4%, 50.1 ± 5.4% and 33.6 ± 5.4%, respectively, and the values increased with age. Girls had higher SvO2 and lower AVD than boys (p < 0.05). The Pearson correlation coefficients among spherical equivalent (SE) and SaO2, SvO2 and AVD were −0.372, −0.203 and −0.240, respectively (all p < 0.001), while the correlations between AL and SaO2, SvO2 and AVD were 0.276, 0.106 and 0.221, respectively (all p < 0.001). The myopia group had significantly higher SaO2, SvO2 and AVD than the emmetropia and hyperopia groups (p < 0.001), but the high myopia group had lower SaO2 and SvO2 than the moderate myopia group. When age, gender, body mass index (BMI), intraocular pressure (IOP) and axial length (AL) were included as factors in the multiple regression, older age was associated with higher SaO2, SvO2 and AVD, while longer AL was associated with higher SaO2 and AVD. Gender was an independent factor predicting SvO2, while gender and BMI were the independent factors predicting AVD. Age explained more variance than AL in SaO2, SvO2 and AVD. Conclusions: Our population‐based study provides age‐specific profiles of retinal oxygen saturation in Chinese children and adolescents. Older age and longer AL were important independent factors of increased retinal oxygen saturation. [ABSTRACT FROM AUTHOR]

Importance Myopia is a major public health concern worldwide, while outdoor time is indicated to be protective against the onset of myopia. Background: To describe the methodology and baseline data of the Shanghai Time Outside to Reduce Myopia (STORM) trial. Design A 2‐year, school‐based, prospective, cluster randomized trial. Participants: Children from grade I and II classes of 24 schools from eight districts in Shanghai, China, were randomized to either a control group, a test group I (40‐min outdoor time/day) or test group II (80‐min outdoor time/day). Methods: At baseline and annual intervals, cycloplegic autorefraction and axial length measurement will be performed. Time outdoors and light exposure will be monitored via parent/carer questionnaires and a wearable device. Main Outcome Measures: Spherical equivalent, prevalence of myopia and time outdoors in each group. Results: A total of 6295 eligible children (age 7.2 ± 0.7 y [6‐9 y]) were randomized to control (n = 2037), test group I (n = 2329) and test group II (n = 1929). At baseline, spherical equivalent was +0.98 ± 1.02D, +1.02 ± 1.02D and +1.00 ± 0.99D (P = 0.708), myopia prevalence was 8.9, 7.7 and 7.8% (P = 0.270) and time outdoors was 58.5 ± 35.8, 59.8 ± 34.7 and 58.5 ± 35.3 min/d (P = 0.886) for control, test groups I and II, respectively. Conclusions and Relevance: Myopia prevalence was high at nearly 8 to 9% in school children aged 7 years in Shanghai, China. The current trial will help evaluate if increased time outdoors has a role to play in reducing the incidence of myopia and/or slow the progression of myopia. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this project is to explore the changes in and factors associated with asymmetry between the superior and inferior hemiretina in children with different refractive levels. Materials and Methods: A total of 2964 children from 12 primary and middle schools in Shanghai, China, were included. The mean thickness of the GCL+ layer (ganglion cell layer+ inner plexiform layer), the GCC layer (ganglion cell complex, a combination of the retinal nerve fiber layer and the GCL+ layer), and the neural retina was measured according to the sectors defined by the Early Treatment of Diabetic Retinopathy Study (ETDRS) grid with swept-source optical coherence tomography. The asymmetry index (AI), calculated via the formula AI = |log10 (superior/inferior hemiretinal layer thickness) |, was used to assess the asymmetry of each retinal layer. Results: The mean age of the children was 11.67 (3.45) years old. The AIs of all retinal layers were larger in myopes than in hyperopes and emmetropes in the perifoveal region (all p < 0.001), and the AIs became even larger in the GCL+ layer and neural retina in children with a higher degree of myopia. However, no statistical differences were observed between various refractive groups in the parafoveal region. Regression analyses indicated that with increasing myopia, the asymmetry of retinal layers increased in the perifoveal region (all p < 0.001) and slightly decreased in the parafoveal region (all p < 0.05). Conclusions and relevance: The vertical asymmetry of retinal layers increased in the perifoveal region in myopic children, and the change in asymmetry was more obvious in the GCL+ layer and neural retina than in the GCC layer. [ABSTRACT FROM AUTHOR]

Abstract: Importance: Nearly half of children suffering vision impairment reside in China with myopia accounting for the vast majority. Background: To describe the design and methodology of the Shanghai Child and Adolescent Large‐scale Eye Study (SCALE). Design: The SCALE was a city wide, school‐based, prospective survey. Participants: Children and adolescents aged 4–14 years from kindergarten (middle and senior), primary schools and junior high schools of all 17 districts and counties of the city of Shanghai, China were examined in 2012–2013. Methods: Each enrolled child underwent vision assessment (distance visual acuity; uncorrected and with corrective device if worn) and their parent/carer completed a questionnaire designed to elicit risk factors associated with myopia. Additionally, non‐cycloplegic autorefraction and ocular axial length was measured in a subset of the larger sample. Main Outcome Measures: Prevalence and the associated factors of vision impairment, myopia and high myopia in Shanghai. Results: In 2012–2013, a total of 910 245 of the eligible 1 196 763 children and adolescents identified from census (76%, mean age 9.0 ± 2.7 years [4–14 years]) were enrolled with visual acuity screened in the city of Shanghai. Of these, 610 952 children (67% of the entire sample) underwent non‐cycloplegic autorefraction and 219 188 (24% of the entire sample) had both non‐cycloplegic autorefraction and axial length measurements. Conclusions and Relevance: The study results will provide insights on the burden of vision impairment, myopia and high myopia in children and adolescents in a metropolitan area of China, and contribute to the policies and strategies to address and limit the burden. [ABSTRACT FROM AUTHOR]

Purpose. To investigate the refraction and ocular biometry characteristics and to examine the prevalence of refractive errors in preschool children aged 3 to 6 years in Shanghai, China. Methods. A school-based cross-sectional study was conducted in Jiading and Xuhui District, Shanghai, in 2013. We randomly selected 7 kindergartens in Jiading District and 10 kindergartens in Xuhui District, with a probability proportionate to size. The children underwent comprehensive eye examinations, including cycloplegic refraction and biometric measurements. Myopia, hyperopia, astigmatism were defined as spherical equivalent (SE) ≤ −0.50 D, SE ≥ +2.00 D, and cylindrical diopters ≤ −1.00 D. Results. The mean SE for 3- to 6-year-old children was +1.20 D (standard deviation [SD] 1.05), and the mean axial length (AL) was 22.29 mm (SD 0.73). The overall prevalence of myopia and astigmatism was 3.7% and 18.3%, respectively. No difference in prevalence of astigmatism was found across age groups. There was a statistically significant association between lower cylindrical diopters and higher spherical diopters (Spearman’s correlation: −0.21, P<0.001). Conclusion. Chinese children aged 3 to 6 years in the Shanghai area were mostly mildly hyperopic, with a low prevalence of myopia. Refractive astigmatism for children may be relatively stable throughout the preschool stage. Astigmatism was significantly associated with refractive error. [ABSTRACT FROM AUTHOR]

Purpose To systematically analyse the differences between cycloplegic and noncycloplegic refractive errors ( RE) in children and to determine if the predictive value of noncycloplegic RE in categorizing RE can be improved. Methods Random cluster sampling was used to select 6825 children aged 4-15 years. Autorefraction was performed under both noncycloplegic and cycloplegic (induced with 1% cyclopentolate drops) conditions. Paired differences between noncycloplegic and cycloplegic spherical equivalent ( SE) RE were determined. A general linear model was developed to determine whether cycloplegic SE can be predicted using noncycloplegic SE, age and uncorrected visual acuity ( UCVA). Results Compared to cycloplegia, noncycloplegia resulted in a more myopic SE (paired difference: −0.63 ± 0.65D, 95% CI: −0.612 to −0.65D, 6017 eligible right eyes) with greater differences observed in younger participants and in eyes with more hyperopic RE and smaller AL. Using raw noncycloplegic data resulted in only 61% of the eyes being correctly classified as myopic, emmetropic or hyperopic. Using age and uncorrected VA in the model, the association improved and 77% of the eyes were classified correctly. However, predicted cycloplegic SE continued to show large residual errors for low myopic to hyperopic RE. Applying the model to only those eyes with uncorrected VA <6/6 resulted in an improvement ( R2 = 0. 93), with 80% of the eyes correctly classified. A higher VA cut-off (i.e., ≤6/18) resulted in 97.5% of eyes classified correctly. Conclusion Noncycloplegic assessment of RE in children overestimates myopia and results in a high error rate for emmetropic and hyperopic RE. Adjusting for age and applying uncorrected VA cut-offs to noncycloplegic assessments improves detection of myopic RE and may help in identifying myopic RE in situations where cycloplegia is not available but does not help in identifying the magnitude of refractive error and therefore is of limited value. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the association between the AL/CR ratio and refractive state and explore the effectiveness of this ratio in the assessment of myopia, especially when combined with uncorrected visual acuity in schoolchildren among whom myopia is common. Methods: Cross sectional study. 4686 children from 6 primary schools, aged from 6 to 12 years were selected using the clustered-stratified random sampling method. Uncorrected visual acuity (UCVA), axial length (AL), corneal radius of curvature (CR), and cycloplegic refraction were tested. Refraction was measured as the spherical equivalent (SE). Results: 3922 children were included in the analysis. The mean AL/CR ratio was 2.973±0.002, increased with age, and different in gender. The coefficients of correlations of the SE with the AL/CR ratio, AL, and CR were -0.811, -0.657, and 0.095, respectively. Linear regression showed a 10.72 D shift towards myopia with every 1 unit increase in the AL/CR ratio (P<0.001, r2 = 66.4%). The estimated SE values obtained by substituting the AL/CR ratio and gender back to the regression model that were within a difference of ±0.50 D in ATE/LER (allowable total error and limits for erroneous results) zones compared to the actual measured values was 51%. The area under the ROC curve of the AL/CR ratio, AL, and UCVA for myopia detection were 0.910, 0.822, and 0.889, respectively, and the differences between each pair were statistically significant (P<0.01). At a specificity of 90%, the sensitivities were 72.98%, 50.50%, 71.99%, and 82.96%, respectively, for the AL/CR ratio, AL, UCVA, and the combination of the AL/CR ratio and UCVA. Conclusions: The AL/CR ratio was found to explain the total variance in SE better than AL alone. The effectiveness of the AL/CR ratio was statistically significantly better than UCVA for detecting myopia in children, and combining the two produced increased sensitivity without significantly decreasing specificity. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion To explore the longitudinal changes in retinal and choroidal thickness and their relation with the onset of type 1 diabetes mellitus (T1DM) in children.Thirty‐eight children with T1DM and 71 healthy controls were included in this 3‐year longitudinal study. Ophthalmic and systemic examinations were conducted on each participant. Retinal and choroidal thickness were measured by optical coherence tomography. Baseline values and changes in retinal and choroidal thickness were compared with DR onset, diabetics without DR and healthy controls. Logistic regression was used to explore the association with DR development.Six children developed DR during the follow‐up period (15.79%) and five of them developed microaneurysms in the parapapillary temporal quadrant. During follow‐up, greater retinal thickening occurred in subjects with DR compared with diabetic participants without DR (p = 0.03) and healthy controls (p = 0.02) in the parapapillary outer temporal section. Compared with the control group, greater retinal thickening was observed in DR subjects in the averaged parapapillary outer ring (p = 0.01), the macular inner temporal section (p = 0.03) and several macular sections (all p < 0.05). Additionally, greater retinal thickening was observed in several parapapillary regions in non‐DR T1DM participants compared with healthy controls (all p < 0.05). The thickness change in the outer temporal parapapillary section was independently associated with DR onset (OR = 1.33, 95% CI 1.01–1.73, p = 0.04).Children with T1DM showed a significant or a trend of increasing retinal and choroidal thickness compared with normal controls over a 3‐year period. The change of retinal thickness in the parapapillary outer temporal section was associated with the development of DR in children with T1DM, suggesting that it could serve as a biomarker for predicting and screening DR in these individuals. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effectiveness and cutoffs of axial length/corneal radius (AL/CR) ratio for myopia detection in children by age. Methods: Totally, 21 kindergartens and schools were enrolled. Non-cycloplegic autorefraction (NCAR), axial length (AL), horizontal and vertical meridian of corneal radius (CR1, CR2), and cycloplegic autorefraction were measured. Receiver operating characteristic (ROC) curve was used to obtain the effectiveness and cutoff for myopia detection. Results: Finally, 7803 participants aged 3–18 years with mean AL/CR ratio of 2.99 ± 0.16 were included. Area under the ROC curve (AUC) of AL/CR ratio for myopia detection (0.958 for AL/CR1, 0.956 for AL/CR2, 0.961 for AL/CR) was significantly larger than that of AL (0.919, all P < 0.001), while AUCs of the three were similar with different cutoffs (> 2.98, > 3.05, and > 3.02). When divided by age, the ROC curves of AL/CR ratio in 3- to 5-year-olds showed no significance or low accuracy (AUCs ≤ 0.823) in both genders. In ≥ 6-year-olds, the accuracies were promising (AUCs ≥ 0.883, all P < 0.001), the cutoffs basically increased with age (from > 2.93 in 6-year-olds to > 3.07 in 18-year-olds among girls, and from > 2.96 in 6-year-olds to > 3.07 in 18-year-olds among boys). In addition, boys presented slightly larger cutoffs than girls in all ages except for 16 and 18 years old. For children aged 3–5 years, AL/CR ratio or AL combined with NCAR increased AUC to > 0.900. Conclusion: AL/CR ratio provided the best prediction of myopia with age-dependent cutoff values for all but preschool children, and the cutoffs of boys were slightly larger than those of girls. For preschool children, AL/CR ratio or AL combined with NCAR is recommended to achieve satisfactory accuracy. AL/CR ratio calculated by two meridians showed similar predictive power but with different cutoffs. [ABSTRACT FROM AUTHOR]

The purpose of the cross-sectional study is to describe the values and distribution of choroidal thickness and to explore its related factors, especially age, in Chinese children. A total of 3001 Chinese school children aged 6 to 19 years underwent comprehensive ophthalmic examinations, including axial length and cycloplegic refraction. Choroidal thickness was measured by swept-source optical coherence tomography (SS-OCT). There was a greater difference in the more central regions between the myopes and emmetropes. Multiple regression analysis was performed to determine the associated factors of choroidal thickness. The results demonstrated that age was independently positively related to choroidal thickness for emmetropes (β = 3.859, p < 0.001), and mild myopes with spherical equivalent greater than −2.00 D (−1.25 D < spherical equivalent ≤ −0.50 D: β = 3.476, p = 0.006; −2.00 D < spherical equivalent ≤ −1.25 D: β = 3.232, p = 0.020). However, no significant relationship between age and choroidal thickness was found in children with spherical equivalent ≤ −2.00 D, suggesting that the protective effect of physiologic choroidal growth with age against rapid axial elongation disappeared while axial elongation becomes the dominant determinant of choroidal thickness among children with myopia worse than −2.00 D. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate common strategies for screening myopia. Methods: A total of 2,248 children aged 6 to 12 years from five randomly selected primary schools were included for the screening. Enrolled study participants underwent distant uncorrected visual acuity (UCVA, Standard Logarithmic Visual Acuity E Chart) and non-cycloplegic auto-refraction (NCAR, Topcon KR-8800). Among them, 1,639 children (72.9%) accepted cycloplegic auto-refraction. Taking rejection of cycloplegia into account, receiver operating characteristic curves were drawn to compare the accuracies of the four strategies (I, Cycloplegic auto-refraction; II, NCAR; III, UCVA; IV, Combination of UCVA and NCAR). Decision curve analysis (DCA) was used to compare net benefits. Tenfold cross-validation was used for statistical analyses. Results: For myopia (spherical equivalent refraction, SE ≤ −0.5D) screening, the mean sensitivities were 73.79% (SD: 5.40%), 85.57% (6.84%), 59.71% (13.49%), and 85.06% (6.68%) for Strategy I to IV; with mean specificities of 100% (0%), 87.43% (4.27%), 89.74% (10.25%), and 88.65% (5.07%), respectively. For screening early myopia (SE ≤ −0.5D and ≥−1.0D), the mean sensitivities were 73.44% (7.69%), 82.39% (5.32%), 54.27% (14.58%), and 81.76% (9.60%) for Strategy I to IV; with mean specificities of 100% (0%), 79.13% (4.86%), 85.48% (9.86%), and 81.17% (4.16%). Based on DCA, the net benefits of Strategy IV were the highest, with the probability thresholds ranging from 12% to 50%, after adjusting the TestHarms. For early myopia, the net benefits of Strategy IV were the highest with the probability threshold ranging from 5% to 34%. Conclusion: Combination of UCVA and NCAR produced the highest net benefits for myopia screening. [ABSTRACT FROM AUTHOR]

Anisometropia can affect visual development in children. Investigations of anisometropia in high myopes would explore potential causes related to anisometropia, highlighting the management of anisometropia in high myopia. The prevalence of anisometropia ranged from 0.6% to 4.3% in general paediatric population and from 7% to 14% in myopes. Anisometropia is regarded as an associated factor for myopia development, while myopia progression is a stimulus driving anisometropic development. The purpose of this study was to investigate the prevalence of anisometropia and its association with refraction development in Chinese children with high myopia. In the cohort study, a total of 1,577 highly myopic (spherical equivalent ≤−5.0D) children aged 4–18 years were included. Refractive parameters (dioptre of sphere, dioptre of cylinder, corneal curvature radius, and axial length) of both eyes were measured after cycloplegia. The prevalence and degree of anisometropia were compared among refractive groups (non-parametric tests or chi-square tests), and regression analyses were used to determine associated factors of anisometropia. The statistical significance was set to P < 0.05 (two-tailed). In highly myopic children with a mean (standard deviation) age of 13.06 (2.80) years, the proportions of spherical equivalent anisometropia, cylindrical anisometropia and spherical anisometropia ≥1.00 D were 34.5%, 21.9% and 39.9%, respectively. There was more spherical equivalent anisometropia associated with more severe astigmatism (P for trend <0.001). In the multivariate regression analysis, more spherical equivalent anisometropia, cylindrical anisometropia and spherical anisometropia were associated with higher degrees of astigmatism (standard beta = −0.175, −0.148 and −0.191, respectively). More spherical anisometropia was associated with better spherical power (standard beta = 0.116). The proportion of anisometropia in highly myopic children was high, compared with previously reported general population, and more severe anisometropia was associated with higher degree of cylindrical power, but not spherical power. [ABSTRACT FROM AUTHOR]

Purpose: To describe the association of refraction development and axial length (AL) in young children and provide new insights into the progression of cylinder power. Methods: Children (2–3 grades) were enrolled from primary schools in Shanghai and followed up for two years. Cycloplegic refraction, AL, and corneal curvature radius were measured. Refraction parameters were compared among groups with different AL, AL1 (AL < 23.5 mm), AL2 (23.5 mm ≤ AL < 24.5 mm), and AL3 (AL ≥ 24.5 mm). Multiple regression analysis was used to explore risk factors of diopter of cylinder (DC) progression. Results: In total, out of 6891 enrolled children, 5961 participants (7–11 yrs) were included in the final analysis. Over the two-year period, the cylinder power significantly changed, and those with longer AL had more rapid DC progression over the two years (AL1, -0.09 ± 0.35 D; AL2, -0.15 ± 0.39 D; AL3, -0.29 ± 0.44 D) (P < 0.001). The change in DC was independently associated with AL at baseline (P < 0.001). The proportion of with-the-rule astigmatism increased from 91.3% to 92.1% in AL1 group, from 89.1% to 91.8% in AL2 group and from 87.1% to 92.0% in AL3 group. Conclusions: Young children with long AL experienced rapid progression of cylinder power. Both the control of myopia progression and attention to the correction of astigmatism are necessary in the health management of children with long AL. The significantly increased AL in participants might contribute to both the extent and direction of astigmatism. [ABSTRACT FROM AUTHOR]

Purpose: To determine how orthokeratology (ortho‐k) affects corneal biomechanical properties in myopia control and whether corneal biomechanical parameters can predict clinical efficacy of ortho‐k. Methods: A total of 125 children 7–15 years of age using ortho‐k lenses were followed in this clinical practice and data of their right eyes were analysed. Corneal biomechanical parameters and most ocular biometry were measured at baseline, 1 week, and at 1, 3, 6, 12, 18 and 24 months. Axial length (AL) was collected every 6 months after baseline measurements. Results: During the 2‐year follow up, nine corneal biomechanical parameters, including deformation amplitude maximum (DA), varied between baseline and 1 week (p < 0.05) and stabilized during the rest of wearing period (p > 0.05). The mean AL increased from 25.02 ± 0.84 mm to 25.38 ± 0.81 mm and baseline DA strongly correlated with AL progression (Pearson r = 0.37). In the multiple regression models, baseline age, AL and DA were the independent factors for AL progression (R2: 0.7849, 0.2180 in low and moderate myopes). The area under the receiver operating characteristic curves using the three variables for predicting excessive AL progression (>0.35 mm during 2 years) in low and moderate myopes was 0.902 and 0.698. Conclusions: Corneal biomechanics firstly fluctuated before becoming stable with long‐term ortho‐k use. Corneal biomechanics was associated with AL progression in children wearing ortho‐k lenses. DA combined with age and AL at baseline could predict AL progression in low myopes using ortho‐k. [ABSTRACT FROM AUTHOR]

Introduction: Orthokeratology (OK) and low-concentration atropine are recommended approaches for controlling myopia. However, children with younger age and lower myopia are more likely to experience rapid axial progression during OK or atropine monotreatment. This study aimed to assess the efficacy of OK combined with low-concentration atropine for myopia control in children over 24 months and to determine whether the effect was sustainable. Methods: In this retrospective study, we reviewed medical records of baseline and follow-up visits from children (7–14 years) applying OK for myopia control. Sixty-eight children receiving monoorthokeratology treatment (OK group) and 68 children who received 0.01% atropine in combination with orthokeratology simultaneously (AOK group) were included. A series of ophthalmic tests at baseline were conducted, and axial length (AL) was measured every 6 months. The comparison of AL change at different visits between the two groups was performed by repeated measures multivariate analyses of variance (RM–MANOVA). Results: There were no significant differences in baseline characters between the two groups (p > 0.05). The AL significantly increased over time in both groups (all p < 0.05), and the 2-year change in AOK was 0.16 mm (36%) lower than in OK (0.28 ± 0.22 mm versus 0.44 ± 0.34 mm, p = 0.001). Compared with OK group, the significant suppression of AL elongation in the AOK group was observed in 0–6, 6–12, and 12–18 month periods (suppression rate: 62.5%, 33.3%, 38.5%, respectively, p < 0.05), while there was no significant difference in the 18–24 month period (p = 0.105). The multiple regression analysis showed an interaction between age and treatment effect (interaction coefficient = 0.06, p = 0.040), indicating one year age decrease approximately associated with 0.06 mm increased retardation in AL elongation in the AOK group. Conclusion: The add-on effect of 0.01% atropine in OK wearers only occurred within 1.5 years, and younger children benefited more from the combination treatment. [ABSTRACT FROM AUTHOR]

Purpose: Due to pubertal development and crystalline lens compensation, axial length (AL) continues to increase among non-progressive myopic children (absolute annual spherical equivalent (SE) progression less than 0.25 diopter), but the amount is unknown. This study was to investigate the cutoff of AL change to accurately differentiate between progressive and non-progressive myopes. Methods: A total of 8,546 myopic and treatment-naive children aged 6–10 years were enrolled from two cohort studies. AL with optical biometer and cycloplegic SE with auto refraction were evaluated at baseline and annually. Annual AL change was calculated, and the percentiles of annual axial elongation among progressive and non-progressive myopes were estimated by quantile regression with restricted cubic spline. Area under receiver-operating characteristic (ROC) curve (AUROC), positive predictive value (PPV), and negative predictive value (NPV) were applied to evaluate the accuracy of predicting progressive and non-progressive myopes. Results: Among 8,546 myopic children, 603 (7.06%) were non-progressive myopes. Annual AL changes among non-progressive myopes remained stable with the median annual change being 0.25 mm, while the median for progressive myopes decreased with age from 0.58 to 0.42 mm. AUROC for distinguishing between non-progressive and progressive myopes was 0.88 and was > 0.85 for each age group. Annual AL change, the cutoff of 0.20 mm/year, had significantly high PPV and NPV in predicting progressive myopes with high proportion of progressive myopes and non-progressive myopes with low proportions of progressive myopes. Conclusion: Myopic children with non-progressive status had markedly less axial elongation than progressive ones. AL changes with cutoff of 0.20 mm/year could differentiate between non-progressive and progressive status and may be an alternative for evaluating progressive status. [ABSTRACT FROM AUTHOR]

Background: To explore the relationship between outdoor time and academic performance among school-aged children. Methods: This study was designed as a cross-sectional study. Data were derived from a school-based prospective children myopia intervention study (STORM). Outdoor time was recorded by self-developed algorithm-validated wristwatches in real-time and calculated as the cumulative average of 10 months. The academic performance was recorded and provided by the participating schools and further standardized. Other information was collected using an online standardized questionnaire. Mixed-effects model and B-Spline method were used to investigate the association between time spent on different types of daily activity, including outdoor activity and academic performance. Results: A total of 3291 children with mean age 9.25 years were included in the final analysis. Overall, outdoor time was associated with academic performance in a non-linear manner; specifically, not exceeding 2.3 h per day, outdoor time was positively associated with academic performance; exceeding 2.3 h per day, this association became non-significant. Likewise, daily sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner, resulting in turning points of 11.3 and 1.4 h per day, respectively. Separate analysis showed that outdoor time and sleep duration but not out-of-school learning time were positively associated with academic performance in Chinese, mathematics and English. Conclusion: Outdoor time, sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner. Promotion of outdoor time may not negatively impact on academic performance. Trial registration: Our study was registered in ClinicalTrials.gov (Identifier: NCT02980445). [ABSTRACT FROM AUTHOR]

Purpose: To report calculated crystalline lens power and describe the distribution of ocular biometry and its association with refractive error in older Chinese adults. Methods: Random clustering sampling was used to identify adults aged 50 years and above in Xuhui and Baoshan districts of Shanghai. Refraction was determined by subjective refraction that achieved the best corrected vision based on monocular measurement. Ocular biometry was measured by IOL Master. The crystalline lens power of right eyes was calculated using modified Bennett-Rabbetts formula. Results: We analyzed 6099 normal phakic right eyes. The mean crystalline lens power was 20.34 ± 2.24D (range: 13.40–36.08). Lens power, spherical equivalent, and anterior chamber depth changed linearly with age; however, axial length, corneal power and AL/CR ratio did not vary with age. The overall prevalence of hyperopia, myopia, and high myopia was 48.48% (95% CI: 47.23%–49.74%), 22.82% (95% CI: 21.77%–23.88%), and 4.57% (95% CI: 4.05–5.10), respectively. The prevalence of hyperopia increased linearly with age while lens power decreased with age. In multivariate models, refractive error was strongly correlated with axial length, lens power, corneal power, and anterior chamber depth; refractive error was slightly correlated with best corrected visual acuity, age and sex. Conclusion: Lens power, hyperopia, and spherical equivalent changed linearly with age; Moreover, the continuous loss of lens power produced hyperopic shifts in refraction in subjects aged more than 50 years. [ABSTRACT FROM AUTHOR]

Air pollution is associated with vision loss in children, but the relationship with vision trajectories has not been explored. The study was conducted as a prospective cohort in 16 districts of Shanghai from 2021 to 2023, involving 5612 children with complete survey data. Each child underwent 3–4 eye tests, including unaided visual acuity and computerized refraction. Children's air pollutant exposure levels (PM 2.5 , PM 10 , O 3 , SO 2 , NO 2 , and CO) were assessed using school addresses and examination dates. Latent class mixture modeling was used to identify the trajectories of changes in vision-related measurements in children. Multinomial logistic regression and Cox proportional hazards regression were used to examine the association of air pollutant exposure and visual trajectories, as well as visual impairment outcomes. The study identified three trajectory categories for children's unaided visual acuity, spherical equivalent, and four trajectory categories for axial length. Increased levels of PM 2.5 , PM 10 , O 3 , and SO 2 exposure are associated with an increased risk of categorizing vision-related measurements into the "poor" category trajectory in children. Increased exposure to PM 2.5 , O 3 , and NO 2 was associated with an increased risk of visual impairment outcomes in children with normal vision at baseline, and the effect was more significant in female and older children. [Display omitted] • Children's vision measurements show several different trajectories. • Air pollutant exposure is associated with a trajectory of "poor" vision in children. • Air pollutant exposure increases the risk of visual impairment in children. • Air pollution has a significant impact on the vision of older children. [ABSTRACT FROM AUTHOR]

To evaluate the relationship between ocular magnification correction and macular choroidal thickness (ChT) measurements in children, and to demonstrate when ocular magnification correction is necessary. Chinese children aged 6–9 years with various refractive statuses were included. Swept-source optical coherence tomography was used to measure macular ChT. A self-designed program was adopted to simulate ChT changes in each sector of the ETDRS grid in the macula under various simulated axial lengths (ALs). ChT measurements were not affected for all simulated ALs in over 95% of the individuals in the central fovea. In the inferior, superior, and temporal parafoveal sectors, the extent of AL that may include 95% of the individuals narrowed from approximately 22.0 mm to 27.2 mm. In the nasal parafoveal sector and inferior, superior, and temporal perifoveal sectors, the extent of AL that may include 95% of the individuals became even narrower, from approximately 22.8 mm to 26.0 mm. The narrowest extent was observed in the perifoveal nasal sector, ranging from 23.3 mm to 25.5 mm. The effect of ocular magnification was more significant in hyperopes than in myopes in the inferior parafoveal sector and temporal, superior, and nasal perifoveal sectors. During macular ChT measurements, ocular magnification correction is not necessary in the central fovea. However, ocular magnification should be corrected normally in the nasal perifoveal region and in individuals with ALs shorter than 22.8 mm or longer than 26.0 mm in the remaining macular regions. [ABSTRACT FROM AUTHOR]

Corneal thickness (CT) maps of the central (2-mm diameter), para-central (2 to 5-mm diameter), peripheral (5 to 6-mm diameter), and minimum (5-mm diameter) cornea were measured in normal Chinese school children aged 7 to 15 years old using Fourier-domain optical coherence tomography. Multiple regression analyses were performed to explore the effect of associated factors [age, gender, refraction, axial length and corneal curvature radius (CCR)] on CT and the relationship between central corneal thickness (CCT) and intraocular pressure (IOP). A total of 1228 eyes from 614 children were analyzed. The average CCT was 532.96 ± 28.33 μm for right eyes and 532.70 ±28.45 μm for left eyes. With a 10 μm increase in CCT, the IOP was elevated by 0.37 mm Hg, as measured by noncontact tonometry. The CT increased gradually from the center to the periphery. The superior and superior nasal regions had the thickest CTs, while the thinnest points were primarily located in the inferior temporal cornea. The CCT was associated with CCR (p = 0.008) but not with gender (p = 0.075), age (p = 0.286), axial length (p = 0.405), or refraction (p = 0.985). In the para-central region and the peripheral cornea, increased CT was associated with younger age, male gender, and a flatter cornea. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the prevalence and associated factors of fundus tessellation in highly myopic children and adolescents. Methods: A total of 513 high myopes (spherical equivalent [SE] ≤ −5.0 D, 4–19 years of age) without any advanced pathological myopic lesions were enrolled. Fundus photographs and choroidal thickness (ChT) data were collected by SS‐OCT. A novel grading approach was adopted to classify fundus tessellation into four categories on colour fundus photography, referring to the location of tessellation divided by an Early Treatment Diabetic Retinopathy Study grid centred on the fovea, through which closer to the fovea represents higher grades of fundus tessellation. Peripapillary atrophy (PPA) area and ovality index were also measured. Results: Among the participants, with a mean age of 13.47 ± 3.13 years and mean SE of − 8.34 ± 1.91 D, there were 29 (5.7%), 95 (18.5%), 233 (45.4%) and 156 (30.4%) participants with grade 0 to grade 3 fundus tessellation, respectively. The ChT in both the macular and peripapillary area was negatively correlated with the fundus tessellation grade (R = −0.763 and −0.537, respectively, all p < 0.001). Higher grades of fundus tessellation were independently associated with thinner macular ChT (OR = 1.734, 95% CI: 1.621–1.856, p < 0.001), longer axial length (OR = 1.368, 95% CI: 1.105–1.695, p = 0.004), larger PPA area (OR = 1.391, 95% CI: 1.073–1.802, p = 0.013) and the female sex (OR = 1.605, 95% CI: 1.092–2.359, p = 0.016). Conclusion: The fundus tessellation grade could reflect the ChT, representing the severity of myopic maculopathy among young high myopes who rarely had any advanced lesions of pathological myopia. Fundus tessellation grade might be a potential index for assessing early‐stage myopic maculopathy in children and adolescents. [ABSTRACT FROM AUTHOR]

Purpose: To document one‐year changes in refraction and refractive components in preschool children. Methods: Children, 3–5 years old, in the Jiading District, Shanghai, were followed for one year. At each visit, axial length (AL), refraction under cycloplegia (1% cyclopentolate), spherical dioptres (DS), cylinder dioptres (DC), spherical equivalent refraction (SER) and corneal curvature radius (CR) were measured. Results: The study included 458 right eyes of 458 children. The mean changes in DS, DC and SER were 0.02 ± 0.35 D, −0.02 ± 0.33 D and 0.01 ± 0.37 D, while the mean changes in AL, CR and lens power (LP) were 0.27 ± 0.10 mm, 0.00 ± 0.04 mm and − 0.93 ± 0.49 D. The change in the SER was linearly correlated with the baseline SER (coefficient = −0.147, p < 0.001). When the baseline SER was at 1.05 D (95% CI = 0.21 to 2.16), the change in SER was 0 D. The baseline SER was also linearly associated with the change in LP (coefficient = 0.104, p = 0.013), but not with the change in AL (p = 0.957) or with the change in CR (p = 0.263). Conclusion: In eyes with a baseline SER less than +1.00 D, LP loss was higher compared to axial elongation, leading to hyperopic shifts in refraction, whereas for those with baseline SER over this range, loss of LP compared to axial elongation was reduced, leading to myopic shifts. This model indicated the homeostasis of human refraction and explained how refractive development leads to a preferred state of mild hyperopia. [ABSTRACT FROM AUTHOR]

Swept-source optical coherence tomography (SS-OCT) is widely used to diagnose high myopia due to its advantage in imaging the ocular anatomic structures. Although the scleral deformation provides information on the risk of the high myopia, further validation of these highly promising findings in clinical studies has been limited by the current semi-automated software, which requires human input, and the automatic analysis of the scleral structure is quite challenging due to the ambiguous boundaries. To address these challenges, we propose a deep contour attention network (DCANet) for automatic segmentation of scleral deformation structure. Specifically, we design a scale-aware attention feature fusion module to achieve cross-scale feature fusion, which can facilitate the network to learn complementary information from multi-scale features. In addition, we develop a pyramid feature enhancement module to allow the network to learn global contextual features through the combination of receptive field and attention mechanism, and we also propose a boundary heatmap label to enrich boundary information. We evaluate the performance of the proposed method on two in-house SS-OCT datasets. In addition to the multiple metrics that are used for evaluating the segmentation performance, including Jaccard similarity coefficient, dice similarity coefficient and boundary distance error, we also propose length similarity coefficient and angle similarity coefficient to evaluate the length estimation and angle estimation, respectively. The experimental results show that our method can effectively improve the segmentation performance, and our DCANet achieves the overall best performance on two datasets compared with other state-of-the-art networks. Our findings motivate the development of clinically applicable deep learning systems for the prediction of high myopia progression on the basis of the scleral phenotypes from SS-OCT images. [ABSTRACT FROM AUTHOR]

Purpose: To study the retinal capillary microvasculature and the choriocapillaris (CC) in myopic eyes using swept-source optical coherence tomography angiography (SS-OCTA). Methods: Patients with high myopia (≥ − 6D; axial length ≥ 26.5 mm), moderate myopia (≥ − 3D, < − 6D), and age-matched healthy subjects presenting to the Shanghai General Hospital and Doheny-UCLA Eye Centers were enrolled in this prospective, multicenter study. Any subjects with evidence of macular abnormalities suggestive of pathologic myopia were excluded. SS-OCTA at both sites was performed using a Zeiss PLEX Elite instrument with a 6 × 6 mm scan pattern centered on the fovea. Two repeated volume scans were acquired for image averaging. The instrument pre-defined en face slab of the superficial and deep retinal capillary microvasculature was used to isolate and display the superficial and deep retinal capillaries. A slab spanning from 21 to 31 μm deep to the RPE fit line was used to isolate and display the CC. The OCTA images were exported for averaging using Image J. Littmann's method and the Bennett formula were applied to adjust for the impact of magnification in the high and moderate myopia groups. The resultant images were then binarized. Though projection artifact removal software was used, regions below the large superficial retinal vessels were excluded for quantitative analyses of the deep retinal capillary plexus and the CC. Vessel density (VD) and vessel length density (VLD) of the superficial and deep retinal capillary plexus (SCP, DCP) and CC flow deficit (FD) were analyzed, quantified, and compared between different groups. Results: Twenty-five eyes of 25 patients with high myopia, 25 eyes of 25 patients with moderate myopia, and 25 eyes of 25 normal age-matched controls were included in this study. The VD of the SCP was lower in the high myopia group compared with the emmetropic control groups (p < 0.05), but the VD of the DCP demonstrated no significant difference among the three groups (p > 0.05). The VLDs of the SCP were lower in the high and moderate myopia groups compared with the control group (p < 0.05), while the VLD of the DCP was lower in the high myopia group compared with the moderate myopia and emmetropic control group (p < 0.05). The CC FD% in the high myopia group was significantly greater than both the control and moderate myopia subjects (p < 0.05). Of note, the severity of the CC flow deficit was not correlated with choroidal thickness (p > 0.05). Conclusion: The retinal microvasculature may demonstrate alterations in highly myopia eyes. The CC in macular regions shows greater impairment in eyes with high myopia compared with eyes with lesser degrees of myopia, and these deficits are already present in the absence of features of pathologic or degenerative myopia. The threshold of CC FD leading to myopic maculopathy remains to be defined. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to explore the association between diabetic retinopathy (DR) and the variants of uncoupling proteins (UCPs) genes in a Chinese population of type 2 diabetes, in total and in patients of different glycemic status separately. Methods: This case-control study included a total of 3107 participants from two datasets, among which 662 were DR patients (21.31%). Eighteen tag single nucleotide polymorphisms (SNPs) of UCP1, UCP2, and UCP3 were selected as genetic markers. TaqMan probes, Sequenom MassARRAY MALDI-TOF mass spectrometry platform and Affymetrix Genome-Wide Human SNP Array were used for genotyping. Online SHEsis software was used for association analysis. Bonferroni correction was used for multiple comparisons correction. Results: Three SNPs of UCP1: rs7688743 (A allele, OR = 1.192, p = 0.013), rs3811787 (T allele, OR = 0.863, p = 0.023), and rs10011540 (G allele, OR = 1.368, p = 0.004) showed association with DR after the adjustment of glucose, but only rs10011540 was marginally significantly associated with DR when Bonferroni correction was strictly applied (padj = 0.048). In patients with uncontrolled glucose, rs7688743 (A allele, p = 0.012, OR = 1.309), rs10011540 (G allele, p = 0.033, OR = 1.432), and rs3811787 (T allele, p = 0.022, OR = 0.811) were associated with DR, while in participants with well controlled glucose, the rs2734827 of UCP3 was associated with DR (A allele, p = 0.017, OR = 0.532). Rs3811787 of UCP1 showed a protective effect to sight threatening DR (T allele, p = 0.007, OR = 0.490), and the association existed after the adjustment for environmental factors and the correction. In patients with uncontrolled glucose, the rs3811787 of UCP1 (T allele, p = 0.017, OR = 0.467) and the rs591758 of UCP3 (C allele, p = 0.026, OR = 0.103) were associated with STDR. While in those with well controlled glucose, only the rs7688743 of UCP1 showed a protective effect (A allele, p = 0.024, OR = 0.049). None of the associations remain significant when Bonferroni correction was strictly applied (all p < 0.05). Conclusions: The rs10011540 and rs3811787 of the UCP1 gene was marginally significantly associated with DR in Chinese type 2 diabetes patients. There might be different mechanisms of DR development in patients with different glycemic status. [ABSTRACT FROM AUTHOR]

Purpose: To explore the subfoveal thickness of sclera (SST), choroid (SCT) and retina (SRT) as well as their relationship in healthy Chinese children with varying levels of refractive error. Methods: A total of 810 healthy Chinese schoolchildren and adolescents underwent a series of comprehensive ocular examinations, as well as swept‐source optical coherence tomography (OCT) after induced cycloplegia. The thicknesses of the sclera, choroid and retina below the central fovea were measured manually, and each measurement was compared across different refractive statuses. Independent factors associated with the thickness of each layer were analysed. Results: The mean SST, SCT and SRT were 524 ± 57 μm, 195 ± 49 μm and 224 ± 19 μm, respectively. The SSTs and SCTs of myopes were significantly thinner than those of emmetropes and hyperopes (all p < 0.001). Although the choroid seemed to be thicker in hyperopes (225 ± 46 μm) than in emmetropes (211 ± 45 μm), no statistically significant difference was observed between emmetropes and hyperopes in the sclera and choroid. Thinner SSTs and SCTs were associated with greater levels of myopia, whereas the SRT was similar in children with different myopic levels. SST (p < 0.001) and SCT (p = 0.003) as well as age (p < 0.001), sex (p < 0.001) and axial length (p < 0.001) were independently associated with spherical equivalent refraction (SER). Older age (p = 0.013), myopic‐shifted SER (p < 0.001), thicker SCT (p < 0.001) and thinner SRT (p = 0.012) were independently associated with a thinner SST. Conclusion: The subfoveal sclera and choroid were thinner in myopes than in emmetropes and hyperopes, while the retina remains constant. Age, refractive error and choroidal and retinal thicknesses are related to subfoveal scleral thickness. [ABSTRACT FROM AUTHOR]

Importance Cohort studies could not only reveal associations between change of refractive components and onset/progression of myopia, but also risk factors, which is important for understanding mechanism and providing strategies. Background: Prevalence of myopia is high in Shanghai, being reported to be 52.2% in children aged 10 years old. Design Cohort study. Participants: A total of 1856 students from six randomly selected primary schools in Baoshan District, Shanghai. Methods: Children underwent comprehensive ocular measurement, including axial length (AL), corneal curvature radius and cycloplegic auto‐refraction. Questionnaires about eye usage time were collected. Grade 1 students were followed for 4 years, and grade 2 and 3 students for 2 years. Main Outcome Measures: (i) Change of spherical equivalent (SE) and AL and (ii) risk factors for progression and incidence of myopia. Results: The average 2‐year progress of SE was 0.91D, 0.91D and 1.11D for grade 1, 2 and 3, respectively, and the average elongation of AL was 0.70 mm, 0.64 mm and 0.71 mm, respectively. Only parental myopia, but not near work time, near work diopter time, outdoor activity time or attending tutoring classes, was associated with myopia incidence and progression in the present population. Using baseline SE could be a simple and effective indicator for myopia prediction. Conclusions and Relevance: Incidence and progression of myopia is relatively high in schoolchildren in Shanghai compared with children of Western countries, East Asia and other parts of China. Effective strategies to control myopia prevalence are in urgent need. [ABSTRACT FROM AUTHOR]

Outdoor time is considered to reduce the risk of developing myopia. The purpose is to evaluate the evidence for association between time outdoors and (1) risk of onset of myopia (incident/prevalent myopia); (2) risk of a myopic shift in refractive error and c) risk of progression in myopes only. A systematic review followed by a meta-analysis and a dose-response analysis of relevant evidence from literature was conducted. PubMed, EMBASE and the Cochrane Library were searched for relevant papers. Of the 51 articles with relevant data, 25 were included in the meta-analysis and dose-response analysis. Twenty-three of the 25 articles involved children. Risk ratio ( RR) for binary variables and weighted mean difference ( WMD) for continuous variables were conducted. Mantel-Haenszel random-effects model was used to pool the data for meta-analysis. Statistical heterogeneity was assessed using the I2 test with I2 ≥ 50% considered to indicate high heterogeneity. Additionally, subgroup analyses (based on participant's age, prevalence of myopia and study type) and sensitivity analyses were conducted. A significant protective effect of outdoor time was found for incident myopia (clinical trials: risk ratio ( RR) = 0.536, 95% confidence interval ( CI) = 0.338 to 0.850; longitudinal cohort studies: RR = 0.574, 95% CI = 0.395 to 0.834) and prevalent myopia (cross-sectional studies: OR = 0.964, 95% CI = 0.945 to 0.982). With dose-response analysis, an inverse nonlinear relationship was found with increased time outdoors reducing the risk of incident myopia. Also, pooled results from clinical trials indicated that when outdoor time was used as an intervention, there was a reduced myopic shift of −0.30 D (in both myopes and nonmyopes) compared with the control group ( WMD = −0.30, 95% CI = −0.18 to −0.41) after 3 years of follow-up. However, when only myopes were considered, dose-response analysis did not find a relationship between time outdoors and myopic progression ( R2 = 0.00064). Increased time outdoors is effective in preventing the onset of myopia as well as in slowing the myopic shift in refractive error. But paradoxically, outdoor time was not effective in slowing progression in eyes that were already myopic. Further studies evaluating effect of outdoor in various doses and objective measurements of time outdoors may help improve our understanding of the role played by outdoors in onset and management of myopia. [ABSTRACT FROM AUTHOR]

Background: Very few studies have explored the effects of age, time period, and cohort in association with biological, behavioral, economic, and environmental factors predictors on physical activity (PA) and sedentary behaviour (SB) among Chinese children.Methods: We used data from a cohort study of the China Health and Nutrition Survey (CHNS) between 2004 and 2011 (2004, 2006, 2009 and 2011). The outcomes of interest were metabolic equivalent of task (MET) hours per week from both active and sedentary activities. Age, gender, individual characteristics, household size, asset ownership, and urbanisation were included as covariates. Age, period and cohort effects analyses for PA and SB of children (6-17 y, n = 3528) was conducted to explicitly assess differences in PA and SB due to age vs. period effects, and implicitly assess differences by cohorts due to the period-specific experiences across individuals of varying ages.Results: The mean age of the sample in each time point fluctuated from 12.6 to 11.3 years and PA slightly decreased from 50.0 ± 63.2 MET hours per week (MET-hr./wk) in 2004 to 47.1 ± 54.9 MET-hr./wk. in 2011. However, SB increased from 31.8 ± 22.0 MET-hr./wk. to 37.6 ± 22.2 MET-hr./wk. Girls had lower PA and higher SB levels than boys. Controlling for age effects, marginal period effects on PA were observed in some survey years. Higher levels of urbanisation and number of household computers served as negative and positive predictors for PA and SB, respectively. Higher household income was a positive predictor of SB. Surprisingly, bigger household size was the only negative predictor of SB (P < 0.05).Conclusions: This longitudinal study followed a large cohort of children over a significant period of their childhood. We observed potential age and secular trends in PA levels. Higher community urbanisation and number of home computers were associated with both PA and SB levels. Larger household size was the only factor that was negatively associated with SB. These findings shed light on health policy and preventative health strategies for China and other countries that are now facing similar public health challenges. [ABSTRACT FROM AUTHOR]

Purpose To calculate crystalline lens power and to determine the relationship between ocular biometry and diabetic retinopathy (DR) in an adult population with type 2 diabetes mellitus (T2DM). Design Cross-sectional, population-based study. Participants Patients with T2DM from the Beixinjing community, Changning district, Shanghai. Methods Random clustering sampling was used to identify adults with T2DM in the Beixinjing community. Spherical equivalent (SE) was determined by subjective refraction that achieved the best corrected vision. Axial length (AL), corneal power (CP), and anterior chamber depth (ACD) were measured using the IOLMaster. Diabetic retinopathy and diabetic macular edema (DME) were assessed according to the international DR classification. Main Outcome Measures The crystalline lens power was calculated using the Bennett–Rabbetts formula. The AL–to–corneal radius ratio (AL/CR ratio) was defined as the axial length divided by the mean corneal radius of curvature. Results A total of 4011 eyes of 2057 subjects with T2DM were included in the analysis. In multivariate logistic models adjusting for age, sex, duration of diabetes, glycosylated hemoglobin A1c, serum creatinine, body mass index, systolic blood pressure, and cataract, after categorizing values into quartiles, there were trend associations between lens power and any DR ( P = 0.01), between AL/CR ratio and any DR ( P = 0.02), and between AL and any DR ( P = 0.03), between lens power and moderate DR ( P = 0.02), and between AL and moderate DR ( P = 0.02); eyes with higher AL/CR ratio were less likely to have any DR (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.24–0.78; P = 0.01 per 1 increase) and moderate DR (OR, 0.44; 95% CI, 0.21–0.93; P = 0.03 per 1 increase), eyes with longer AL were less likely to have any DR (OR, 0.88; 95% CI, 0.81–0.95; P = 0.002 per millimeter increase) or moderate DR (OR, 0.89; 95% CI, 0.80–0.98; P = 0.02 per millimeter increase), and eyes with higher SE were more likely to have any DR (OR, 1.08; 95% CI, 1.03–1.13; P = 0.003 per diopter increase). Conclusions In persons with T2DM, lens power, AL/CR ratio, and AL were associated with the presence of any DR and moderate DR. These findings suggested that globe elongation plays a major role in protective effects against DR, with contributions from lens power and other refractive components. [ABSTRACT FROM AUTHOR]

We investigated the prevalence of clinical trachoma in 154,265 children aged 6 to 16 years in 206 Shanghai migrant schools. Clean water availability in school, each child’s facial cleanliness, eyelids, corneas, and the presenting distance visual acuities were examined. Trachoma was clinically diagnosed in accordance with the World Health Organization simplified classification. Eyes diagnosed with trachoma were swabbed to test for ocular Chlamydia trachomatis infections (OCTI) with a rapid latex immunochromatographic test. Among 153,977 students, no blindness was found related to trachoma. Trachoma was diagnosed in 8029 children (5.2%). In 87 schools clinical trachoma prevalence was higher than 5%. OCTI was confirmed in 2073 of 6823 trachoma diagnosed children (30.4%). Clinical trachoma prevalence was higher among females than males (p<0.001), but gender comparison showed no statistical difference in the prevalence of OCTI (p=0.077). Age and clinical trachoma (r=-0.014; p<0.001) or OCTI (r=-0.026; p=0.031) prevalence were negatively correlated. Clinical trachoma was different in different districts and counties (p<0.001). Trachoma warrants close attention in Shanghai migrant children because the condition remains endemic in some schools. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the characteristics of various near work related behaviors among primary students and their associations with changes in myopia related ocular biometric parameters during one-year of follow up. Methods: A school-based sample of 4,814 primary 1st to 4th grade students aged 6–10 years old were selected by cluster randomization based on probability proportion to size in 2013. At baseline, students together with their parents filled in a self-administered questionnaire on 9 aspects of near work related behaviors and some important covariants of myopia. A comprehensive set of eye examinations including axial length (AL) and cycloplegic refraction was conducted both at baseline and one year later. Results: With the grade level increase, students did increasingly better at finding various ways to have an eye break, but they were increasingly likely to continuously do long-time near work without an eye break. Keeping a reasonable eye distance and correct hand posture for reading, writing, or watching TV became worse for the first time before grade 2, but then became better at grade 3. In contrast, selecting appropriate lighting environments or situations and keeping a balanced diet became better for the first time before grade 2, but then became worse at grade 3. At one-year follow up, the mean AL increased by 0.32 ± 0.35 mm, the ratio of AL divided by the mean corneal radius of curvature (AL/CR ratio) increased by 0.032 ± 0.054, the myopic spherical equivalent (SE) increased by -0.51 ± 0.51 diopters and the incidence of myopia was 16.0% (237/1,477). After controlling for the confounding effects of parental myopia, student’s age, gender, height, daily near work time, daily outdoor activity time and all of the other near work related behaviors, keeping a reasonable distance when reading, writing and watching TV was associated with elongation of the AL [standard coefficient beta = -0.062, P = 0.004], a change in SE [beta = -0.072, P = 0.020] and incident myopia [adjusted odds ratio (aOR) = 0.90, 95% confidence interval (CI): 0.84–0.96]. Selecting an environment with adequate light for visual comfort to read and write was related to elongation of the AL [beta = -0.039, P = 0.034] and increase of AL/CR ratio [beta = -0.030, P = 0.048]. Also, not continuing to do near work for more than 30–40 minutes without an eye break was related to increase of the AL/CR ratio [beta = -0.028, P = 0.044] and a change in SE [beta = -0.064, P = 0.023]. Conclusion: Various near work related behaviors changed according to grade level in primary school students. Independent of hereditary factors, daily near work load and outdoor activity, near work related behaviors such as keeping an inappropriate eye distance for near work, selecting inadequate lighting environments, and continuing to do near work without an eye break were risk factors for myopic shifts. [ABSTRACT FROM AUTHOR]

Purpose. To investigate the changes of anterior segment after cycloplegia and estimate the association of such changes with the changes of refraction in Chinese school-aged children of myopia, emmetropia, and hyperopia. Methods. 309 children were recruited and eligible subjects were assigned to three groups: hyperopia, emmetropia, or myopia. Cycloplegia was achieved with five cycles of 0.5% tropicamide. The Pentacam system was used to measure the parameters of interest before and after cycloplegia. Results. In the myopic group, the lenses were thinner and the lens position was significantly more posterior than that of the emmetropic and hyperopic groups in the cycloplegic status. The correlations between refraction and lens thickness (age adjusted; r=0.26, P<0.01), and lens position (age adjusted; r=-0.31, P<0.01) were found. After cycloplegia, ACD and ACV significantly increased, while ACA significantly decreased. Changes in refraction, ACD, ACV, and ACA were significantly different among the three groups (P<0.05, all). Changes of refraction were correlated with changes of ACD (r=0.41, P<0.01). Conclusions. Myopia presented thinner lenses and smaller changes of anterior segment and refraction after cycloplegia when compared to emmetropia and hyperopia. Changes of anterior chamber depth were correlated with refraction changes. This may contribute to a better understanding of the relationship between anterior segment and myopia. [ABSTRACT FROM AUTHOR]

Purpose: To explore the effectiveness of using a series of tests combining near visual acuity (NVA) and distance visual acuity (DVA) for large-scale screenings for significant refractive error (SRE) in primary school children. Method: Each participant underwent DVA, NVA and cycloplegic autorefraction measurements. SREs, including high myopia, high hyperopia and high astigmatism were analyzed. Cycloplegic refraction results were considered to be the gold standard for the comparison of different screening measurements. Receiver-operating characteristic (ROC) curves were constructed to compare the area under the curve (AUC) and the Youden index among DVA, NVA and the series combined tests of DVA and NVA. The efficacies (including sensitivity, specificity, positive predictive value, and negative predictive value) of each test were evaluated. Only the right eye data of each participant were analysed for statistical purpose. Result: A total of 4416 children aged 6 to 12 years completed the study, among which 486 students had right eye SRE (SRE prevalence rate = 11.01%). There was no difference in the prevalence of high hyperopia and high astigmatism among different age groups. However, the prevalence of high myopia significantly increased with the age (χ² = 381.81, p<0.01). High hyperopia was the biggest SRE factor associated with amblyopia（p＜0.01，OR = 167.40, 95% CI: 75.14∼372.94). The DVA test was better than the NVA test for detecting high myopia (Z = 2.71, p<0.01), but the NVA test was better for detecting high hyperopia (Z = 2.35, p = 0.02) and high astigmatism (Z = 4.45, p<0.01). The series combined DVA and NVA test had the biggest AUC and the highest Youden Index for detecting high hyperopia, myopia, astigmatism, as well as all of the SREs (all p<0.01). Conclusion: The series combined DVA and NVA test was more accurate for detecting SREs than either of the two tests alone. This new method could be applied to large-scale SRE screening of children, aged 6 to 12, in areas that are less developed. [ABSTRACT FROM AUTHOR]

Background To assess the prevalence of visual impairment and rate of wearing spectacles in schools for children of migrant workers in Shanghai, China. Methods Children from grade 1 to 5 in schools for children of migrant workers were randomly chosen for ocular examinations. All children were screened for uncorrected visual acuity and presenting visual acuity. After screening, the children whose uncorrected visual acuity was 20/40 or less received ocular motility evaluation, cycloplegic refraction/non-cycloplegic refraction, and external eye, anterior segment, media, and fundus examinations. Results A total of 9673 children were enumerated and 9512 (98.34%) participated in this study. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye were 13.33%, 11.26%, and 0.63%, respectively. The rate of wearing spectacles of the children with visual impairment in one or both eyes was 15.50%. Of these, 26.05% were wearing spectacles with inaccurate prescriptions. Refractive error was a major cause of visual impairment, accounting for 89.48% of all the visual impairment causes. Other causes of visual impairment included amblyopia accounting for 10.12%; congenital cataract, 0.1%; congenital nystagmus, 0.1%; ocular prosthesis, 0.1%; macular degeneration, 0.05%; and opaque cornea, 0.05%. Conclusions This is the first study of the prevalence and causes of visual impairment in schools for children of migrant workers in Shanghai, China. The visual impairment rate in schools for children of migrant workers in suburbs of Shanghai in the best eye before vision correction was lower than those of urban children in mainstream schools in Guangzhou in 2012, and higher than students in rural of Beijing in 1998 and in suburb of Chongqing in 2007. The refractive error was the principal cause of the visual impairment of the children of migrant workers. The rate of wearing spectacles was low and the percentage of inaccurate prescriptions, among those who wore spectacles, was high. Uncorrected refractive error was a significant cause of visual impairment in migrant children. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Objective: To investigate the association between the TNF-α-308G/A polymorphism and ocular chlamydia trachomatis (C. Trachomatis) infection among Han Chinese children. Methods: 248 patients and 162 matched healthy controls were recruited. The diagnosis of ocularC. Trachomatisinfection was given after clinical observation and latex immunochromatography tests. The TNF-α-308G/A polymorphism was genotyped by sequencing. Results: No association was found between the TNF-α-308G/A polymorphism and ocularC. Trachomatisinfection. Conclusions: The TNF-α-308A polymorphism is unlikely to play a major role in the risk for ocularC. Trachomatisin the Chinese population. [ABSTRACT FROM PUBLISHER]

Myopia, a leading cause of distance vision impairment, is projected to affect half of the world's population in 30 years. We analysed the relationship between certain demographic, environmental, and behavioural factors and myopia from a 2-year school-based, prospective trial conducted in Shanghai, China. This trial enrolled 6295 school-aged children at baseline and followed them up for 24 months. The relationship between abovementioned factors and myopia was examined and the role of sleep in childhood myopia development was highlighted. Our results suggest that 'sleeping late' is a risk factor for myopia prevalence at baseline (odds ratio [OR] = 1.55, p = 0.04), 2-year myopia incidence (odds ratio [OR] = 1.44, p = 0.02) and progression over 24 months (p = 0.005), after adjusting for residency area, age, gender, sleep duration, and time spent outdoors. The identification and consistency of results with late sleepers being a susceptible group to both myopia onset and progression suggests a complex relationship between circadian rhythm, indoor environment, habitual indoor activities and myopia development and progression. These results can offer new insights to future myopia aetiology studies as well as aid in decision-making of myopia prevention strategies. [ABSTRACT FROM AUTHOR]

Background: Wearable smart watches provide large amount of real-time data on the environmental state of the users and are useful to determine risk factors for onset and progression of myopia. We aim to evaluate the efficacy of machine learning algorithm in differentiating indoor and outdoor locations as collected by use of smart watches.Methods: Real time data on luminance, ultraviolet light levels and number of steps obtained with smart watches from dataset A: 12 adults from 8 scenes and manually recorded true locations. 70% of data was considered training set and support vector machine (SVM) algorithm generated using the variables to create a classification system. Data collected manually by the adults was the reference. The algorithm was used for predicting the location of the remaining 30% of dataset A. Accuracy was defined as the number of correct predictions divided by all. Similarly, data was corrected from dataset B: 172 children from 3 schools and 12 supervisors recorded true locations. Data collected by the supervisors was the reference. SVM model trained from dataset A was used to predict the location of dataset B for validation. Finally, we predicted the location of dataset B using the SVM model self-trained from dataset B. We repeated these three predictions with traditional univariate threshold segmentation method.Results: In both datasets, SVM outperformed the univariate threshold segmentation method. In dataset A, the accuracy and AUC of SVM were 99.55% and 0.99 as compared to 95.11% and 0.95 with the univariate threshold segmentation (p < 0.01). In validation, the accuracy and AUC of SVM were 82.67% and 0.90 compared to 80.88% and 0.85 with the univariate threshold segmentation method (p < 0.01). In dataset B, the accuracy and AUC of SVM and AUC were 92.43% and 0.96 compared to 80.88% and 0.85 with the univariate threshold segmentation (p < 0.01).Conclusions: Machine learning algorithm allows for discrimination of outdoor versus indoor environments with high accuracy and provides an opportunity to study and determine the role of environmental risk factors in onset and progression of myopia. The accuracy of machine learning algorithm could be improved if the model is trained with the dataset itself. [ABSTRACT FROM AUTHOR]

The article presents a study that investigated the prevalence and causes of visual impairment and blindness associated with type 2 diabetes mellitus (T2DM) in mainland China. The study involved a population-based, cross-sectional survey among 2016 adult T2DM residents living in Shanghai, China, examined patients for blindness and visual impairment, and revealed that a large proportion of subjects with impaired vision caused by cataract do not avail of cataract surgery services.

Background: To investigate the prevalence and risk factors of visual impairment associated with refractive error and the unmet need for spectacles in a special suburban senior population in Baoshan District of Shanghai, one of several rural areas undergoing a transition from rural to urban area, where data of visual impairment are limited.Methods: The study was a population based survey of 4545 Chinese aged (age: >60 years or older ) at Baoshan, Shanghai, in 2009. One copy of questionnaire was completed for each subject. Examinations included a standardized refraction and measurement of presenting and best corrected visual acuity (BCVA) as well as tonometry, slit lamp biomicroscopy, and fundus photography.Results: The prevalence of mild (6/12 to 6/18), moderate (6/18 to 6/60) and severe visual impairment was 12.59%, 8.38% and 0.44%, respectively, and 5.26%, 3.06% and 0.09% with refractive correction. Visual impairment was associated with age, gender, education and career, but not insurance . The prevalence of correctable visual impairment was 5.81% (using 6/18 cutoff) and 13.18% (using 6/12 cutoff). Senior people and women were significantly at a higher risk of correctable visual impairment, while the well-educated on the contrary. The prevalence of undercorrected refractive error (improves by 2 or more lines with refraction) was 24.84%, and the proportion with undercorrected refractive error for mild, moderate , severe and no visual impairment was 61.54%, 67.98%, 60.00% and 14.10%, respectively. The spectacle coverage rate was 44.12%. Greater unmet need for spectacles was observed among elderly people, females, non-peasant, and subjects with less education and astigmatism only.Conclusions: High prevalence of visual impairment, visual impairment alleviated by refractive correction, and low spectacle coverage existed among the senior population in Baoshan District of Shanghai. Education for the public of the importance of regular examination and appropriate and accessible refraction service might be helpful to solve the problem. [ABSTRACT FROM AUTHOR]