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Objectives: The study aims to explore the ocular biometry of a myopic population in Northern China, focusing specifically on anterior and posterior segment lengths. Methods: This is a cross-sectional study. The medical records of 3458 myopic patients who underwent refractive surgery were evaluated. Axial length (AL), anterior chamber depth (ACD), lens thickness (LT) and other biometric parameters were measured using the IOL Master 700. The study determined the anterior segment length (ASL = ACD + LT), the posterior segment length (PSL = AL − ASL) and the ratio of ASL to PSL (ASL/PSL). Results: This study included 3458 eyes from 3458 myopic patients (1171 men and 2287 women). The mean age was 27.38 ± 6.88, ranging from 16 to 48 years old. The mean ASL was 7.35 ± 0.27 mm, and the mean PSL was 18.39 ± 1.18 mm. The ASL and PSL trends demonstrate an age-related increase for both genders, with notable gender-specific variations. Across most age groups, males typically exhibited higher ASLs and PSLs than females, with the exception of the 35–40 and 40–45 age groups. The ASL and PSL consistently increased with a rising AL. The AL strongly correlates with the PSL and negatively correlates with the ASL/PSL ratio. The ACD and LT moderately correlate with the ASL, but an increased LT does not imply a longer posterior segment. The CCT and SE show little correlation with axial eye parameters. Conclusions: Among Chinese myopic patients, a longer ASL and PSL were correlated with older age and the male gender. The AL strongly correlates positively with the PSL and negatively correlates with the ASL/PSL ratio. An elongation of the posterior segment may primarily account for an eyeball's lengthening. [ABSTRACT FROM AUTHOR]

Biometric technology has transformed human biological characteristics into a new form of privacy, and the misuse of this technology poses challenges to protecting this new privacy. This article initially defines biometric technology and biometric characteristics, further demonstrating why biometric characteristics belong to personal privacy and how biometric technology poses challenges to its protection. Through analysis, this article argues that the essence of these challenges is the conflicts between the ethical principle of privacy protection and the ethical principle of maximizing social benefits. In order to address these challenges, it is necessary first to weigh the fundamental ethical principles. The two basic principles of privacy protection and maximizing social benefits are not mutual antagonism but hierarchy, and this hierarchy should be based on the principle of practical feasibility. That is, applying biometric technology should first meet the principle of practical feasibility and, on this premise, realize the principle of maximizing social benefits based on not infringing on the principle of privacy protection. [ABSTRACT FROM AUTHOR]

This article uses the app Health Code, a smartphone-based application for contact tracing and risk assessment that serves as a COVID-19 health passport, as an example to explore how "biometric citizenship," a new mode of preemptive social regulation, functions and malfunctions in contemporary China. First, through a review of China's transition from socialism to neoliberalism, the authors trace how the tenet of citizenship shifts from biological/biopolitical to biometric as the party-state's agenda changes along the process. Second, drawing on media coverage and comments from social media, we show how Health Code consolidates the biometric paradigm of citizenship and turns the relatively stabilized temporal basis of biological/biopolitical citizenship into fragmented temporalities to tighten social control. This preemptive control system improves the state's acumen for self-revamping and self-preservation and enhances its capacities to harness people's re/productivities. It also disrupts the habituated way of living and further marginalizes the groups with diminishing re/productive potentialities. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to describe the distribution and characteristics of ocular biometric parameters among a large Chinese population. Methods: This retrospective cross-sectional study included 146,748 subjects whose ocular biometric parameters were measured at the ophthalmology clinic of West China Hospital, Sichuan University, and recorded in the hospital database. Ocular biometric parameters, including axial length, anterior chamber depth, corneal keratometry, and keratometric astigmatism, were recorded. Only monocular data for each subject were analyzed to avoid bias. Results: Valid data from 85,770 subjects (43,552 females and 42,218 males) aged 3–114 years were included in this study. The mean axial length, mean anterior chamber depth, average corneal keratometry, and mean keratometric astigmatism were 24.61 mm, 3.30 mm, 43.76 D, and 1.19 D, respectively. The stratification of the ocular parameters by age and gender showed significant inter-gender and inter-age differences. Conclusions: Analysis of a large population of subjects in western China aged 3–114 years showed that the distribution and characteristics of ocular biometric parameters, including axial length, anterior chamber depth, corneal keratometry, and keratometric astigmatism, differed by age and gender. This study is the first to describe ocular biometric parameters in subjects aged > 100 years. [ABSTRACT FROM AUTHOR]

The study is to evaluate the performance of ocular biometric measures and uncorrected visual acuity (UCVA) for detecting myopia among Chinese students. Among 5- to 18-year-old Chinese students from two cities of China, trained eye-care professionals performed assessment of ocular biometrics (axial length (AL), corneal curvature radius (CR), anterior chamber depth) under noncycloplegic conditions using NIDEK Optical Biometer AL-Scan, distance visual acuity using retro-illuminated logMAR chart with tumbling-E optotypes, and cycloplegic refractive error using NIDEK autorefractor with administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder, and myopia was defined as SER ≤ − 0.5 D. Performances of ocular biometrics and UCVA (individually and in combination) for detecting myopia were evaluated using sensitivity and specificity, predictive values, and area under ROC curve (AUC) in both development dataset and validation dataset. Among 3436 students (mean age 9.7 years, 51% female), the mean (SD) cycloplegic SER was − 0.20 (2.18) D, and 1269 (36.9%) had myopia. Cycloplegic SER was significantly correlated with AL (Pearson Correlation coefficient r = − 0.82), AL/CR ratio (r = − 0.90), and UCVA (r = 0.79), but was not correlated with CR (r = 0.02, p = 0.15). The AL/CR ratio detected myopia with AUC 0.963 (95% CI 0.957–0.969) and combination with UCVA improved the AUC to 0.976 (95% CI 0.971–0.981). Using age-specific AL/CR cutoff (> 3.00 for age < 10 years, > 3.06 for 10–14 years, > 3.08 for ≥ 15 years) as myopia positive, the sensitivity and specificity were 87.0% (95% CI 84.4–89.6%) and 87.8% (86.0–89.6%), respectively, in the development dataset and 86.4% (95% CI 83.7–89.1%) and 89.4% (95% CI 87.3–91.4%), respectively, in the validation dataset. Combining AL/CR and UCVA (worse than 20/32 for age < 10 years, and 20/25 for ≥ 10 years) provided 91.9% (95% CI 90.4–93.4%) sensitivity and 87.0% (95% CI 85.6–88.4%) specificity, positive value of 80.6% (95% CI 78.5–82.6%) and negative value of 94.8% (95% CI 93.8–95.8%). These results suggest that AL/CR ratio is highly correlated with cycloplegic refractive error and detects myopia with high sensitivity and specificity, AL/CR ratio alone or in combination with UCVA can be used as a tool for myopia screening or for estimating myopia prevalence in large epidemiological studies with limited resources for cycloplegic refraction. [ABSTRACT FROM AUTHOR]

The legal protection of biometric data is becoming an increasingly important issue in the information society. China attaches importance to the legal protection of biometric data. Over the past decades, the rapid development of digital technology has profoundly influenced Chinese information society. However, digital technology may also trigger substantial risks. In this article, we provide an in-depth examination of existing Chinese laws protecting biometric data. We explore general laws and facial recognition laws, administrative regulations, sector-based rules, judicial interpretations, regulatory documents, policy documents, and (draft) national standards. We find gaps in laws in China. Building on this analysis, we elaborate on five principles for the legal protection of biometric data: (1) legality, propriety, and necessity; (2) integrity; (3) purpose; (4) minimization; and (5) controllability. We provide three policy recommendations for the legal protection of biometric data: (1) sufficiently considering the purpose of the collection of biometric data, (2) creating controllable mechanisms, and (3) implementing regulatory compliance programs. [ABSTRACT FROM AUTHOR]

Purpose. To investigate the longitudinal changes and associated factors of axial length (AL) in congenital ectopia lentis (CEL) patients. Methods. In this retrospective study, medical records of CEL patients were reviewed from January 2014 to December 2019 at the Zhongshan Ophthalmic (ZOC) in China. Patients were divided into the surgery group and the nonsurgery group. Data of refractive power, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) as well as ocular biometrics including AL, corneal curvature, white-to-white (WTW), and central corneal thickness (CCT) were collected at baseline and each follow-up visit. Multiple linear regression was performed to assess the potential associated factors for axial length growth in congenital ectopia lentis patients. Results. Compared with the nonsurgery group, the change rate of AL among children aged 3 to 6 years old was slower in the surgery group (0.443 ± 0.340 mm/year vs. 0.278 ± 0.227 mm/year, P < 0.05). However, no statistically significant difference for the change rate of AL was detected between the surgery group and the nonsurgery group (P > 0.05) among patients aged 7 years or older. For the surgery group, the results of the linear regression model showed that a higher change rate of AL was associated with younger age (older age: β = −0.009, 95% CI: −0.014 to −0.003, and P = 0.002) and worse baseline BCVA (logMAR) (β = 0.256, 95% CI: 0.072 to 0.439, and P = 0.007). As for the nonsurgery group, younger baseline age (older age: β = −0.027, 95% CI: −0.048 to −0.007, and P = 0.01) and longer baseline AL (β = 0.073, 95% CI: 0.023 to 0.122, and P = 0.006) were associated with a higher change rate of AL. Conclusions. The AL change rate was clearly associated with age both in the surgery group and in the nonsurgery group. Intervention strategies such as surgery should be performed earlier for CEL that meets the surgical criteria. Worse baseline BCVA and longer baseline AL are associated factors that would affect the growth rate of AL in the surgery and nonsurgery group, respectively. [ABSTRACT FROM AUTHOR]

Objective: To construct fetal limb bone nomograms in the Chinese ethnic population., Methods: This was a prospective cross-sectional study on singleton pregnancies between 12 and 37 weeks of gestation. Femur, tibia, fibula, humerus, ulna, radius, and foot length were measured in a standardized manner by one of the three sonographers. Each fetus's measurements were only included once and those who developed maternal or fetal complications were excluded. Fractional polynomial regression model was used to obtain the 3rd, 10th, 50th, 90th, and 97th centiles for each of the limb measurement. Z -score for the 50th centile of each fetal limb measurement was then compared with published nomograms derived from other populations., Results: Of the 843 scans performed, 775 were included in analysis after excluding conditions such as pre-eclampsia, chromosomal abnormalities, single umbilical artery and skeletal dysplasia. Comparison with other populations showed that Chinese had shorter fetal limb bone lengths than the Caucasian and Afro-Caribbean populations., Conclusion: This study established nomograms for all the fetal limb bones in the Chinese ethnic population, which showed lengths comparatively shorter than Caucasian and Afro-Caribbean nomograms. This would reduce the false alarm of short fetal limb bone lengths and its consequent anxiety and intervention.

Purpose: To assess the accuracy of biometric parameters measured by anterior segment optical coherence tomography (AS-OCT) and partial coherence interferometry (PCI) in prediction of effective lens position (ELP) compared with previous formulas in PACG patients.Methods: 121 PACG eyes were randomly divided into training set (85 eyes) and validation set (36 eyes) with same procedure including AS-OCT, PCI, phacoemulsification and IOL implantation surgery. Preoperative anterior chamber depth (pre-ACD), scleral spur depth (SSD), scleral spur width (SSW), lens vault (LV) and cornea thickness (CT) were measured from AS-OCT image. Axial length (AL) and corneal power (K) were measured by PCI. All the 7 parameters were analyzed by multiple linear regression in training set and a statistic regression formula was developed. In validation set, one-way ANOVA was applied to compare the new regression formula with Sanders-Retzlaff-Kraff theoretic (SRK/T), Holladay 1, Haigis, and a regression formula developed in previous study.Results: The coefficient of determination (R2) of different parameter combinations are 0.19 (pre-ACD, AL), 0.25 (AL, K) and 0.49 (SSD, AL, SSW) in training set. In validation set, the correlation between predicted and measured ELP are: new formula (R2 = 0.50, P = 0.9947) Holladay 1 (R2 = 0.12, P < 0.0001), SRK/T (R2 = 0.11, P < 0.0001) and Haigis (R2 = 0.06, P < 0.0001).Conclusion: Among 7 tested parameters, pre-ACD contribute little in ELP prediction. Formula consist of SSD, AL and SSW showed better accuracy than other formulas tested. [ABSTRACT FROM AUTHOR]

Purpose: To understand the ocular biometric parameters characteristics and refractive errors in 3-to 6-year-old preschool children in Chengdu, China, and to investigate the prevalence of refractive errors., Method: A school-based cross-sectional study was conducted in Chengdu from 2020 to2022 with a total of 666 kindergartens. All children were measured by non-cycloplegic autorefraction and uncorrected visual acuity (UCVA) and ocular biometric parameters. Finally, univariate linear regression models were used to analyze the relationship between ocular biometric parameters and refraction., Results: A total of 108,578 preschool children aged 3-6 underwent examinations, revealing a myopia prevalence of 6.1%. The mean axial length (AL), keratometry (K), corneal radius (CR), axial length/corneal radius (AL/CR) Ratio, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were 22.35 ± 0.69 mm, 43.35 ± 1.58 D, 7.80 ± 0.28 mm, 2.87 ± 0.08, 533.31 ± 32.51 μm, 2.70 ± 0.28 mm, 3.91 ± 0.27 mm, and 15.20 ± 0.68 mm, respectively. With increasing age, AL, CR, AL/CR ratio, CCT, ACD, LT, and VCD also increased. Regardless of age, males consistently exhibited longer AL, flatter corneal curvature, shallower ACD, thicker CCT, thinner LT, and longer VCD compared to females. AL, K, CR, LT, and VCD all showed significant linear relationships with SE (all P < 0.001) in univariate linear regression analysis after adjusting for gender and age., Conclusion: The prevalence of myopia among preschool children aged 3-6 in Chengdu is relatively low. Ocular biometric parameters affecting refractive errors include AL, K, CR, LT, and VCD. The preschool period serves as a critical phase for myopia prevention and control., (© 2024. The Author(s).)

Objective: To investigate the differences in myopia prevalence and ocular biometry in children and adolescents in Chongqing and Tibet, China., Design: Cross-sectional study., Setting: The study included children and adolescents aged 6-18 years in Chongqing, a low-altitude region, and in Qamdo, a high-altitude region of Tibet., Participants: A total of 448 participants in Qamdo, Tibet, and 748 participants in Chongqing were enrolled in this study., Methods: All participants underwent uncorrected visual acuity assessment, non-cycloplegic refraction, axial length (AL) measurement, intraocular pressure (IOP) measurement and corneal tomography. And the participants were grouped according to age (6-8, 9-11, 12-14 and 15-18 years group), and altitude of location (primary school students: group A (average altitude: 325 m), group B (average altitude: 2300 m), group C (average altitude: 3250 and 3170 m) and group D (average altitude: 3870 m))., Results: There was no statistical difference in mean age (12.09±3.15 vs 12.2±3.10, p=0.549) and sex distribution (males, 50.4% vs 47.6%, p=0.339) between the two groups. The Tibet group presented greater spherical equivalent (SE, -0.63 (-2.00, 0.13) vs -0.88 (-2.88, -0.13), p<0.001), shorter AL (23.45±1.02 vs 23.92±1.19, p<0.001), lower prevalence of myopia (39.7% vs 47.6%, p=0.008) and flatter mean curvature power of the cornea (Km, 43.06±1.4 vs 43.26±1.36, p=0.014) than the Chongqing group. Further analysis based on age subgroups revealed that the Tibet group had a lower prevalence of myopia and higher SE in the 12-14, and 15-18 years old groups, shorter AL in the 9-11, 12-14 and 15-18 years old groups, and lower AL to corneal radius of curvature ratio (AL/CR) in all age subgroups compared with the Chongqing group, while Km was similar between the two groups in each age subgroup. Simple linear regression analysis showed that SE decreased with age in both the Tibet and Chongqing groups, with the Tibet group exhibiting a slower rate of decrease (p<0.001). AL and AL/CR increased with age in both the Tibet and Chongqing groups, but the rate of increase was slower in the Tibet group (p<0.001 of both). Multiple linear regression analysis revealed that AL had the greatest effect on SE in both groups, followed by Km. In addition, the children and adolescents in Tibet presented thinner corneal thickness (CCT, p<0.001), smaller white to white distance (WTW, p<0.001), lower IOP (p<0.001) and deeper anterior chamber depth (ACD, p=0.015) than in Chongqing. Comparison of altitude subgroups showed that the prevalence of myopia (p=0.002), SE (p=0.031), AL (p=0.001) and AL/CR (p<0.001) of children at different altitudes was statistically different but the Km (p=0.189) were similar. The highest altitude, Tengchen County, exhibited the lowest prevalence of myopia and greatest SE among children, and the mean AL also decreased with increasing altitude., Conclusions: Myopia prevalence in Tibet was comparable with that in Chongqing for students aged 6-8 and 9-11 years but was lower and myopia progressed more slowly for students aged 12-14 and 15-18 years than in Chongqing, and AL was the main contributor for this difference, which may be related to higher ultraviolet radiation exposure and lower IOP in children and adolescents at high altitude in Tibet. Differences in AL and AL/CR between Tibet and Chongqing children and adolescents manifested earlier than in SE, underscoring the importance of AL measurement in myopia screening., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Clinical relevance: Ocular biometry is key to understanding the determinants of ocular development and pathology changes, especially for the thriving myopic population in Asia. Investigating biometric data in highly myopic eyes within a wide age spectrum is therefore of high importance.Background: To report the magnitude of change in spherical equivalent for each unit of change in the ocular biometry parameters in a highly myopic population in China.Methods: Highly myopic patients aged 7 to 70 years were recruited from the Zhongshan Ophthalmic Center, China. Each patient had a cycloplegic refraction and a measurement of ocular biometry.Results: Data from 823 right eyes were available for analysis, with a mean age of 22.7 years and a median spherical equivalent of -8.88 D. Axial length and lens thickness increased with age, while anterior chamber depth (ACD) decreased in older subjects. There was a significant trend of increasing axial length, lens thickness, vitreous chamber depth (VCD) and decreasing ACD and calculated lens power over spherical equivalent quartiles (all p < 0.001). The univariate linear regression models showed that 1-D change in refraction equalled to a 0.33- to 0.34-mm increase of axial length, and a 0.32 to 0.33-mm increase of VCD in highly myopic eyes. Among the three components of axial length, lens thickness was associated with myopia shift in the groups of 7-18 years and 19-39 years (both p < 0.001), and VCD was significant in all groups (all p < 0.001), while ACD was not significant in any age group.Conclusion: The associations between refraction and axial length were consistent in children, young adults and the elderly with high myopia. Lens thickening with a higher degree of myopia appeared at a very early age, and vitreous chamber depth remained to be a prominent factor of refraction change in highly myopic eyes throughout seven to 70 years of age. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the distribution of ocular biometric parameters and its association to refraction in university students in central China. Methods: Ocular biometric parameters including axial length (AL), central corneal thickness (CCT), keratometry power (K), anterior chamber depth (AQD) and lens thickness (LT) were measured by an optical biometry in a cohort of university students. Corneal radius of curvature (CR), lens position (LP), lens power (PBennett), vitreous chamber depth (VCD) and AL to corneal radius ratio (AL/CR) were calculated. Cycloplegic refraction was measured using an autorefractor. Results: A total of 7650 undergraduate students participated in this study, with a mean age of 20.0 ± 1.4 years. The following ocular biometric parameters were measured: AL (24.78 ± 1.21 mm), CCT (539.83 ± 33.03 μm), AQD (3.23 ± 0.25 mm), LT (3.47 ± 0.18 mm), CR (7.79 ± 0.27 mm), LP (4.97 ± 0.23 mm), VCD (17.55 ± 1.15 mm), PBennett (25.00 ± 1.07 dioptres) and AL/CR (3.18 ± 0.15). Male subjects were found to have longer AL, thicker CCT, flatter CR, thinner lens, deeper AQD and VCD than female ones. Myopic subjects were found to have longer AL, thinner CCT, steeper CR, thinner and posterior lens, deeper AQD and VCD, lower PBennett and larger AL/CR than emmetropes and hyperopes. Spherical equivalent (SE) showed a negative correlation with AL/CR (r = −0.914), AL (r = −0.755) and VCD (r = −0.751). Conclusions: This study provided a range of reference values for the main ocular biometric parameters in young adults and reported their distributions based on gender and refractive status. Our study indicates that SE has a strong correlation with AL/CR ratio, AL and VCD. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate the ocular biometric parameters in adult cataract patients from China and create an anterior chamber depth (ACD) regression model.Methods: The ocular biometric records of 28,709 right eyes of cataract surgery candidates who were treated at Aier Eye Hospitals in nine cities from 2018 to 2019 were retrospectively analyzed. All measurements were taken with IOLMaster 700. We included patients who were at least 40 years old and were diagnosed with cataract.Results: The mean age of the patients was 68.6 ± 11.0 years. The mean values recorded were as follows: axial length (AL), 24.17 ± 2.47 mm; mean keratometry (Km) value, 44.26 ± 1.70 D; corneal astigmatism (CA), 1.06 ± 0.96 D; ACD, 3.02 ± 0.45 mm; lens thickness (LT), 4.52 ± 0.45 mm; central corneal thickness (CCT), 0.534 ± 0.04 mm; and white to white (WTW) corneal diameter, 11.64 ± 0.46 mm. ACD correlated positively with AL (Spearman coefficient, 0.544) and WTW (0.300), but negatively with LT (-0.660) and age (-0.285) (all P < 0.01). In the multivariate regression analysis of ACD, which included LT, AL, WTW, sex, Km, CCT, and age, there was a reasonable prediction with adjusted R2 = 0.641.Conclusions: Cataract patients with longer AL and wider WTW have deeper ACD. With increasing age and lens thickening ACD becomes shallower. Based on the standardized coefficients of ACD multivariate regression analysis from the study, LT is the main factor that affects ACD, and is followed by AL. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between ocular biometrics (OB) and myopia onset. Methods: OB data from students in 4 grades (aged from 6 to 14 years) in China were collected in a 1.5-year longitudinal study. Refractive error was assessed with cycloplegic autorefraction. Results: At baseline, 934 (56.33%) of the subjects (right eye) had myopia. The mean spherical equivalent (SE) and axial length to corneal radius (AL/CR) were − 2.14 ± 1.49 and 3.14 ± 0.11, respectively, in the subjects with myopia and − 0.09 ± 0.21 and 2.98 ± 0.07, respectively, in the subjects without myopia. The correlation between the SE and AL/CR was r = − 0.823 (P < 0.001). The slopes of the SE changing with the AL/CR (and R-squares) were − 0.28 to − 1.80 (0.01–0.14) in the no myopia group, − 3.40 to − 6.20 (0.20–0.48) in the low myopia group, and − 3.37 to − 11.34 (0.16–0.74) in the moderate and high myopia groups. The baseline AL/CR values in grades 1, 3, and 5 were higher in those who developed myopia within 1.5 years. The odds ratio of the AL/CR to myopia onset in 1.5 years was 1.096 (95% confidence interval (CI): 1.060–1.135). Conclusions: Of the five indicators, the AL/CR showed the best correlation with the SE. The adjoint and linear relationship between the AL/CR and the SE tended to increase with SE progression. When myopia progressed beyond a certain range, the AL/CR was significantly different in those without initial myopia who developed it within 1.5 years compared with those who did not. After adjusting for age, sex, school, and grade, the interpretation capability of the current AL/CR to myopia onset in 1.5 years was limited. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the association of body stature with ocular biometrics and refraction in preschool children., Methods: A cross-sectional, school-based study was conducted in Shenzhen, China. Preschool children aged 3 to 6 from 10 randomly-selected kindergartens were recruited. Ocular biometric parameters, including axial length (AL), anterior chamber depth (ACD), vitreous chamber depth (VCD), corneal radius curvature (CR), axial length to corneal radius ratio (AL-to-CR ratio) and lens thickness (LT) were measured using non-contact partial-coherence laser interferometry. Cycloplegic refractions were obtained by a desktop autorefractor. Body height and weight were measured using standard procedures. The association between body stature and ocular biometrics were analyzed with univariable and multivariable regression model., Results: A total of 373 preschoolers were included. AL, ACD, VCD, CR, and AL-to-CR ratio, were positively associated with height and weight (p < 0.05), whereas LT was negatively associated with height and weight (p < 0.01). No association was observed between stature and central cornea thickness and refraction. After adjusted for age and gender in a multivariable regression model, AL had positive associations with height (p < 0.01) and weight (p < 0.01). However, refraction had no significant association with stature parameters., Conclusion: Taller and heavier preschoolers had eyes with longer AL, deeper vitreous chamber, and flatter cornea. The significant associations between body stature and ocular biometric parameters reveal the driving influence of body development on the growth of eyeballs in preschoolers., (© 2024. The Author(s).)

Background: Several studies have previously reported the normal values of corneal volume (CV) in various populations, whereas little is known about the CV distribution in healthy young Chinese adults. Our study aimed to investigate the distribution of CV and its relationships with other ocular biometric parameters among healthy young Chinese adults., Methods: A total of 1645 eyes from 1645 students at Dali University in Yunnan Province, China, were analyzed. Pentacam was used to measure CV. Central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were evaluated by Corvis-ST. Other biometrical parameters, including axial length (AL), keratometry, and white-to-white (WTW) distance, were measured using IOL Master., Results: The mean age of the study population was 19.01 ± 0.92 years, and 68.81% of them were women. The CV was normally distributed in the whole sample, with a mean value of 61.23 ± 3.22 mm 3 . CV and CCT were significantly smaller in the Yi ethnic group than in the Han ethnic group (p < 0.01). CCT (coefficient: 0.085; p < 0.001) and keratometry (coefficient: 0.422; p < 0.001) were positively correlated with CV, while AL (coefficient: -0.204; p < 0.001), WTW distance (coefficient: -0.236; p < 0.001) and bIOP (coefficient: -0.06; p < 0.001) were inversely associated with CV., Conclusions: Our study provides an age-specific distribution of CV among healthy young Chinese adults. CCT, keratometry, AL, WTW distance and bIOP were important factors associated with CV., (© 2024. The Author(s).)

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., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose. To compare ocular biometric parameters between urban and rural cataract patients in Shanghai, China. Methods. A study of ocular biometry records from urban and rural hospitals was performed for cataract patients at least 50 years of age. The ocular biometrical parameters, which were measured with partial coherence laser interferometry (IOL Master, Zeiss), were axial length (AL), anterior chamber depth (ACD), radius of corneal curvature (K, including steep/flat/average K), astigmatism, and axis. Only the right eye record of each patient was analysed. Results. Ocular biometric data included 2839 urban patients (73.15 ± 9.54 years) and 2646 rural patients (73.64 ± 7.32 years). Mean AL, ACD, and K were 24.35 ± 2.34 mm, 3.14 ± 0.58 mm, and 44.38 ± 1.52 D, respectively, in urban patients and 23.58 ± 1.70 mm, 3.08 ± 0.57 mm, and 44.53 ± 1.50 D, respectively, in rural patients. The urban subjects had significantly longer axial lengths (in both univariate and multivariate linear regression analyses) and deeper ACDs (in univariate analysis) than rural subjects p < 0.01 . There was no significant difference in steep K, flat K, and average K between the two groups. With-the-rule (WTR) corneal astigmatism was found in 1787 eyes (32.58%), against-the-rule (ATR) corneal astigmatism was found in 2727 eyes (49.72%), and oblique corneal astigmatism was found in 971 eyes (17.70%). Conclusions. We report biometry and astigmatism data in a large cohort of urban and rural adult subjects for the first time. In our study, a short AL, shallow ACD, and axis turned in an ATR direction had higher prevalence rates in the rural subjects. This profile of ocular biometric data and corneal astigmatism will be helpful in planning for intraocular lens (IOL) power calculations and astigmatism correction in subjects in different locations. [ABSTRACT FROM AUTHOR]

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P < 0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P = 0.111 ; 0.02 ± 0.05 mm, P = 0.022 , respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT. [ABSTRACT FROM AUTHOR]

Purpose: Recent genome-wide association studies (GWAS) have verified eight genetic loci that were significantly associated with primary angle–closure glaucoma (PACG). The present study investigated whether these variants are associated with the ocular biometric parameters of anterior chamber depth (ACD) and axial length (AL) in a northern Chinese population, as well as whether there were differences in the association of genetic markers in our cohort based on ethnicity. Methods: A case-control association study of 500 patients and 720 controls was undertaken. All individuals were genotyped for eight single nucleotide polymorphisms (SNPs) (rs11024102 in PLEKHA7, rs3753841 in COL11A1, rs1015213 located between PCMTD1 and ST18, rs3816415 in EPDR1, rs1258267 in CHAT, rs736893 in GLIS3, rs7494379 in FERMT2, and rs3739821 mapping between DPM2 and FAM102A) using an improved multiplex ligation detection reaction (iMLDR) technique. Allelic and genotypic frequency differences were evaluated using a logistic regression model. Generalized estimation equation (GEE) analysis was conducted for association testing between genotypes and ocular biometric parameters. False discovery rate (FDR) correction for multiple comparisons was employed, and the statistical power was calculated via power and sample size calculation. Results: Four of the eight SNPs, rs3753841, rs1258267, rs736893 and rs7494379, were associated with PACG (p = 0.007, 0.0016, 0.0045, 0.045, respectively), and only rs3753841, rs1258267 and rs736893 surpassed the FDR correction. For subgroup analysis, only rs1258267 could withstand multiple testing correction in the Han nationality (p = 0.00571). In the GEE tests, rs3753841, rs1258267 and rs736893 were found to be nominally associated with ACD (p = 0.023, 0.016, 0.01, respectively). However, these associations could not survive FDR correction. Conclusions: The SNP rs3753841 in COL11A1, rs1258267 in CHAT and rs736893 in GLIS3 are associated with PACG in northern Chinese people, and the association of genetic markers manifests a tendency of ethnic diversity. Larger population-based studies are warranted to reveal additional PACG loci and ethnic aspects of PACG. [ABSTRACT FROM AUTHOR]

Purpose. To investigate the biometric characteristics of Chinese patients with a history of acute angle closure (AAC). Methods. In this clinic-based, retrospective, observational, cross-sectional study, biometric parameters of eyes were acquired from a general population of Chinese adults. The crowding value (defined as lens thickness (LT); central corneal thickness (CCT); anterior chamber depth (ACD)/axial length (AL)) was calculated for each patient. Logistic regression analysis was performed to identify risk factors for AAC. Receiver operating characteristic (ROC) curves were plotted, and biometric variables were compared to compile a risk assessment for AAC. Result. This study included 1500 healthy subjects (2624 eyes, mean age of 66.54 ± 15.82 years) and 107 subjects with AAC (202 eyes, mean age of 70.01 ± 11.05 years). Eyes with AAC had thicker lens (P≤0.001), shallower anterior chamber depth (P≤0.001), and shorter axial length (P≤0.001) than healthy eyes. Logistic regression analysis and ROC curve analysis indicated that a crowding value above 0.13 was a significant (P<0.05) risk factor for the development of AAC. Conclusions. Biometric parameters were significantly different between the eyes from the AAC group to the normal group. Ocular crowding value might be a new noncontact screening method to assess the risk of AAC in adults. [ABSTRACT FROM AUTHOR]

Background: To evaluate the distribution of biometric parameters and corneal astigmatism using the IOLMaster device before phacoemulsification in cataract patients in Central China.Methods: Consecutive cataract patients were recruited at the Central Hospital of Wuhan between January 2015 and June 2016. Ocular axial length (AL), keratometry values, anterior chamber depth (ACD) and horizontal corneal diameter (white to white [WTW]) of each cataract-affected eye were measured with the IOLMaster device.Results: The study evaluated 3209 eyes of 2821 cataract patients. The mean AL, ACD, and WTW were 24.38 ± 2.47 mm, 3.15 ± 0.48 mm, and 11.63 ± 0.43 mm, respectively. Corneal astigmatism of 0.51-1.00 diopters (D) was the most common range of values (34.96%). A total of 10.56% patients exhibited a corneal astigmatism greater than 2.0 D. The flat and steep keratometry values gradually increased with age. The mean ACD and WTW showed increasing trends as the AL increased (P < 0.001). When the AL was shorter than 26.0 mm, the keratometry decreased as AL increased. The against-the-rule (ATR) astigmatism proportion increased with age and the with-the-rule (WTR) astigmatism proportion decreased with age.Conclusions: The profile of ocular biometric data and corneal astigmatism may help ophthalmologists improve their surgical procedures and make an appropriate IOL choice to gain a high quality of postoperative vision. [ABSTRACT FROM AUTHOR]

Background To assess the corneal diameter and its associations in children. Design Cross-sectional school-based study. Participants Six thousand twenty-six children aged 4-18 years were included in the Shandong Children Eye Study. Methods Horizontal corneal diameter was measured by laser interferometry-based ocular biometry. Main Outcome Measures Horizontal corneal diameter. Results Corneal diameter measurements were available for 5970 (99.1%) children. In multivariate analysis, larger horizontal corneal diameter (mean: 12.02 ± 0.38 mm; range: 10.1-15.0 mm) was associated with longer corneal curvature radius longer axial length, male gender, younger maternal age, rural region of habitation and lower intraocular pressure measurements. Higher prevalence of abnormally large corneas (macrocorneas; horizontal diameter ≥ 12.76 mm; mean value +2 × standard deviations; mean: 2.6%; 95% CI: 2.2, 3.0) was associated with longer corneal curvature radius, longer axial length, younger maternal age and male gender. Higher prevalence of abnormally small corneas (horizontal diameter ≤ 11.24mm; mean value −2 × standard deviations; mean: 2.4%; 95% CI: 2.0, 2.8) was correlated with shorter corneal curvature radius, shorter axial length and urban region of habitation. Neither abnormally large nor small corneas were correlated with time spent indoors/outdoors. Conclusions In 4 to 18-year-old children, larger corneal diameter was associated most strongly with flatter corneal curvature, followed by longer axial length and male gender. Corneal diameter was independent of age beyond an age of 4 years. Abnormally large and abnormally small corneas may be defined as being ≥12.76 and ≤11.24 mm in diameter, respectively. Corneal diameter was not correlated with time spent indoors/outdoors. [ABSTRACT FROM AUTHOR]

Purpose: To assess the optimal number and orientation of anterior segment optical coherence tomography (AS-OCT) images for accurately measuring ocular biometric parameters in angle closure eyes., Methods: Subjects with angle closure, defined as > 3 quadrants of non-visible pigmented trabecular meshwork on static gonioscopy, were selected from the Chinese American Eye Study. Mean angle opening distance (AOD500) was calculated using four images (0°-180°, 45°-225°, 90°-270° and 135°-315° meridians) from one eye per subject. Ten eyes from each quartile of AOD500 measurements were randomly selected for detailed 32-image analysis of 10 biometric parameters, including AOD500, iris curvature (IC), anterior chamber depth (ACD), lens vault (LV), and anterior chamber area (ACA). Mean and range of measurements from 1, 2, 4, 8 or 16 images were compared with 32-image values for all parameters., Results: 40 out of 335 eyes with angle closure were selected for 32-image analysis. Deviation from the 32-image mean was between 0.44% and 19.31% with one image, decreasing to 0.08% to 4.21% with two images for all parameters. Deviation from the 32-image range of measurements was between 54.67% to 88.94% with one image, decreasing to <7.00% with eight images for all parameters except ACD and ACA. Orienting the first image analysed along the 25°-205° meridian better approximated the range of measurements when four or fewer images were analysed., Conclusions: Sectoral anatomical variations in angle closure eyes are easily misrepresented based on current AS-OCT imaging conventions. A revised multi-image approach can better capture the mean and range of biometric measurements., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To evaluate the relationship between antenatal pelvic floor biometry and levator ani muscle (LAM) injury in Chinese women.Methods: Three-dimensional transperineal ultrasound was performed in nulliparous Chinese women with a singleton pregnancy at 9-12 weeks, 26-28 weeks and 36-38 weeks of gestation and again at 12 months after delivery. Hiatal anteroposterior (AP) diameter, transverse diameter and area were measured on the antenatal ultrasound volumes obtained at rest, on Valsalva maneuver and during pelvic floor muscle contraction (PFMC). LAM injury was evaluated using ultrasound volumes obtained during PFMC at 12 months after delivery.Results: In total, 328 women completed the study. At 12 months after delivery, 38 (14.8% of those who delivered vaginally) women had LAM injury; 28 were unilateral (14 right- and 14 left-sided) and 10 were bilateral. In all three trimesters there was smaller hiatal AP diameter and hiatal area in women with LAM injury when compared with women without injury. On multivariable analysis of the three factors, hiatal AP diameter at rest, hiatal area at rest and operative vaginal delivery, only hiatal AP diameter at rest in all three trimesters was an independent factor of LAM injury. A larger hiatal AP diameter at rest in the first, second and third trimesters reduced the likelihood of LAM injury with odds ratios of 0.21, 0.15 and 0.21, respectively.Conclusions: A smaller antenatal hiatal AP diameter at rest is a risk factor for LAM injury. The hiatal AP diameter is relatively simple to measure and the error in measurement is relatively small. A prospective study to confirm this relationship and to explore whether this measurement, performed in the midsagittal plane, is repeatable should be performed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Background: Ocular biometry is important for preoperative assessment in cataract and anterior segment surgery. The purpose of this study was to investigate normative ocular biometric parameters and their associations in an older Chinese population.Methods: This was a cross-sectional observational study. From 2013 to 2014, we recruited inhabitants aged 50 years or older in Guangzhou, China. Among 1,117 participants in the study, data from 1,015 phakic right eyes were used for analyses. Ocular parameters including axial length (AL), anterior chamber depth (ACD), and corneal curvature (K) were measured using an IOL Master.Results: The mean AL, ACD, and K were 23.48 mm [95 % confidence interval (CI), 23.40-23.55], 3.03 mm (CI, 3.01-3.05), and 44.20 mm (CI, 44.11-44.29), respectively. A mean reduction in ACD with age was observed (P = 0.002) in male subjects but not in female subjects (P = 0.558). Male subjects had significantly longer ALs (23.68 mm versus 23.23 mm, P < 0.001), deeper ACDs (3.13 mm versus 2.95 mm, P < 0.001), and flatter Ks (43.85D versus 44.50 D, P < 0.001) than female subjects. Eyes with axial elongation had a flatter cornea (r = -0.437, P < 0.001) and a deeper anterior chamber (r = 0.652, p < 0.001). The ACD was correlated with K (r = -0.266, P < 0.001).Conclusions: These data provide normative values for AL, ACD, and K using the IOL Master for a population in South China. The AL in this Chinese cohort was greater than that observed in the Singaporean Chinese but smaller than that observed in Malaysia and for Caucasians. The Chinese have a shallower ACD than some other racial groups. Age and sex were the most consistent predictors of ocular biometry in the older population from South China. [ABSTRACT FROM AUTHOR]

Purpose To analyze biometry data and corneal astigmatism in cataract candidates from Southern China. Setting Guangdong Eye Institute, Guangdong General Hospital, Guangzhou, China. Design Cross-sectional hospital-based study. Methods The axial length (AL), anterior chamber depth (ACD), horizontal corneal diameter (white to white [WTW]), and corneal power (keratometry [K], flat K, steep K) were measured using the IOLMaster system. Ocular biometric data were collected and analyzed between 2007 and 2011. Results The study comprised 6750 eyes of 4561 consecutive cataract candidates with a mean age of 70.4 years ± 10.5 (SD). The mean AL, ACD, and WTW were 24.07 ± 2.14 mm, 3.01 ± 0.57 mm, and 11.68 ± 0.45 mm, respectively. All values were statistically significantly greater in men than in women ( P < .001) and had a significant trend toward a decrease as age increased ( P < .001). The mean K value was 44.13 ± 1.63 D. The median corneal astigmatism was 0.90 D (interquartile range, 0.54-1.43). Corneal astigmatism of 1.00 D or greater was found in 2963 eyes (43.9%), and 3590 eyes (53.2%) had against-the-rule (ATR) astigmatism. The axis of corneal astigmatism turned in the ATR direction with age. Conclusions This study provides reference data for cataract patients from Southern China. The profiles of ocular biometric data and corneal astigmatism can help improve surgical procedures and intraocular lens design for the Chinese population. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]

Myopia has become a major public health issue with an increasing prevalence. There are still individuals who experience similar environmental risk factors and, yet, remain non-myopic. Thus, there might be genetic factors protecting people from myopia. Considering the opposite ocular characteristics of primary angle closure glaucoma (PACG) to myopia and possible common pathway between them, we propose that certain risk genes for PACG might act as a protective factor for myopia. In this study, 2,678 young adults were genotyped for 37 targeted single nucleotide polymorphisms. Compared with emmetropia, rs1401999 (allele C: OR=0.795, P=0.03; genotype in dominant model: OR=0.759, P=0.02) and rs1258267 (allele A: OR=0.824, P=0.03; genotype in dominant model: OR=0.603, P=0.01) were associated with low to moderate myopia and high myopia, respectively. Genotype under recessive model of rs11024102 was correlated with myopia (OR=1.456, P=0.01), low to moderate myopia (OR=1.443, P=0.02) and high myopia (OR=1.453, P=0.02). However, these associations did not survive Bonferroni correction. Moreover, rs1401999, rs1258267, and rs11024102 showed associations with certain ocular biometric parameters in different groups. Our study suggests that ABCC5, CHAT and PLEKHA7 might be associated with refractive errors by contributing to the regulation of ocular biometry, in terms of uncorrected results and their biological functions., (© 2022. Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To describe and compare the prevalence of refractive error and its associated ocular biometric parameters in a large multi-racial sample of schoolchildren from Xinjiang., Methods: A total of 67,102 school children of five ethnicity groups aged 6-23 years from 46 schools in Xinjiang participated in this study. The children underwent a comprehensive eye examination for vision screening, including uncorrected visual acuity and standardized refraction. Refractive error was determined by autorefractors and subjective refraction. Refraction was recorded in spherical equivalent (SE). The age- and sex- adjusted prevalence of myopia (SE ≤ -0.5 D), low myopia (-6 D < SE ≤ -0.5 D), high myopia (SE ≤ -6.0 D), astigmatism (cylinder < -0.5 D), and anisometropia (difference in SE between two eyes of 1.0 D) in the five ethnic groups were calculated. Ocular biometric parameters including axial length (AL) and corneal radius of curvature (CR) were measured by AL-scan optical biometer., Results: The age- and sex- adjusted prevalence of myopia in the Han, Hui, Uyghur, Kyrgyz and Kazakh were 65.8% (95% confidence interval [CI] 65.4, 66.3); 59.1% (95% CI 57.8, 60.4); 30.1% (95% CI 29.2, 30.9); 30.2 (95% CI 28.9, 31.4); and 30.0% (95% CI 27.6, 32.3), respectively. The Han and Hui children also had longer ALs (Han, 23.8; Hui, 23.6, Uyghur, 23.1; Kyrgyz, 23.1; Kazakh, 23.3 mm) and larger AL/CR (Han, 3.04; Hui, 3.00; Uyghur, 2.95; Kyrgyz, 2.96; Kazakh, 2.97) values than the other three minorities (P < 0.01). Overall, girls had shorter ALs, steeper corneas, and smaller AL/CR values than boys (P < 0.01)., Conclusions: Significant ethnic difference in the prevalence of myopia was observed in this study on school-aged children in Xinjiang (Han > Hui > Kyrgyz > Uyghur > Kazakh). This study among different ethnic groups in a multiethnic population is valuable for enriching the ethnical information resources for refractive errors and ocular biometry parameters, as well as facilitating further research on myopia-related diseases and risks., (© 2021. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

Patient's privacy-preserving, security and mutual authentication between patient and the medical server are the important mechanism in connected health care applications, such as telecare medical information systems and personally controlled health records systems. In 2013, Wen showed that Das et al.'s scheme is vulnerable to the replay attack, user impersonation attacks and off-line guessing attacks, and then proposed an improved scheme using biometrics, password and smart card to overcome these weaknesses. However, we show that Wen's scheme is still vulnerable to off-line password guessing attacks, does not provide user's anonymity and perfect forward secrecy. Further, we propose an improved scheme to fix these weaknesses, and use the applied pi calculus based formal verification tool ProVerif to prove the security and authentication. [ABSTRACT FROM AUTHOR]

Background To compare anterior segment biometric parameters between Caucasians and Chinese before and after laser peripheral iridotomy. Design Prospective clinical cohort study. Participants Caucasian and Chinese primary angle-closure suspects. Methods Anterior segment optical coherence tomography images captured before and after laser peripheral iridotomy were analysed to measure anterior segment biometric parameters. Paired Student's t-tests were used for within-ethnic group comparisons. Univariate and linear mixed-effect regression models were used for between-ethnic group comparisons. Main Outcome Measures Angle opening distance, angle recess area, iris thickness, iris curvature, anterior chamber area, anterior chamber volume and anterior chamber width. Results Caucasians had significantly greater preoperative angle recess area, anterior chamber width, and iris curvature and lower preoperative iris thickness compared to Chinese ( P < 0.05). Significant postoperative increases in angle opening distance, angle recess area, anterior chamber area, anterior chamber volume, and anterior chamber width along with significant postoperative decrease in iris curvature were observed within both ethnic groups ( P < 0.05). However, the amount of laser peripheral iridotomy-induced changes in angle opening distance, angle recess area, anterior chamber area, anterior chamber volume, anterior chamber width, and iris curvature did not differ between the two ethnic groups ( P < 0.05). Conclusion Both Caucasian and Chinese demonstrated opening of anterior chamber angle width, expansion of anterior chamber dimensions, and flattening of iris convexity after laser peripheral iridotomy. Although certain aspects of anterior segment anatomy differed between Caucasians and Chinese preoperatively, they did not translate into significant ethnic differences in the amount of laser peripheral iridotomy-induced changes in the anterior segment biometric parameters. [ABSTRACT FROM AUTHOR]

This paper reports on biometrical variation of parthenogenetic Artemia cysts from 12 saline lakes and salterns of China. The results showed that the largest diameter of untreated and decapsulated cysts of the studied populations belong to Aqqikkol Lake (325.4 ± 13.7 μm; 301.4 ± 14.2 μm, respectively) and the smallest from Xiaotan Saltern (258.7 ± 10.8 μm) and Gaodao Saltern (244.3 ± 15.5 μm). The thickest and the thinnest chorion layers are from Yinggehai Saltern (12.2μm) and Aibi Lake (3.5 μm), respectively. Our results confirm that the studied biometrical parameters (the diameters of untreated and decapsulated cysts as well as chorion thickness) present a significant correlations (p < 0.05) and also that the populations at very high-altitude locations have the biggest cysts. However, the regression analysis showed that the correlations between altitude and biometrical parameters of cysts were not significant. The relationship between degree of ploidy and cyst size is not clear, so size is more likely due to the combined effect of ploidy degree, physico-chemical conditions, food availability and population-specific parameters. The present results also suggest that the high standard deviations (SD) and coefficients of variation (CV) in cysts of Barkol population may be related to their complex ploidy composition (2n: 27.4%; 3n: 4.9%; 4n: 37.8% and 5n: 29.9%). Cluster analysis and principal components analysis do not reveal correlation between biogeographical distribution and cyst biometrics. [ABSTRACT FROM AUTHOR]

The regrowth of tropical secondary forests and plantations can not offset the carbon release caused by tropical deforestation, consequently determining net carbon losses on tropical lands. However, large uncertainties remain in relation to this assumption. Here, we used a biometric method to estimate the net dry matter production and net ecosystem production in a rubber forest, the most widespread plantation type in tropical Southeast Asia. According to biometric estimates made during the study, the ecosystem was a carbon sink (790 gC m-2 yr-1). Net ecosystem carbon fluxes were measured by the eddy covariance method. The carbon budget estimated using the FluxNet procedure (904 gC m-2 yr-1) was closer to the biometric estimates in comparison to a method based on data measured during neutral atmospheric conditions. Overall, when considering the whole life cycle, including deforestation of the prior-existing tropical forest, the hypothesis of plantations serving as large carbon sinks is not supported by our study. [ABSTRACT FROM AUTHOR]

Abstract: Difflugia is a morphologically diverse genus of testate amoebae, which are common components of freshwater ecosystems. We observed a new morphotype similar to Difflugia tuberspinifera but without spine in four Xiamen reservoirs, Fujian Province, southeast China. We investigated its morphology and biometry using light and scanning electron microscopy. The linear discriminant analysis and principal component analysis of biometric characters revealed that the spiny and spineless forms of D. tuberspinifera differed only in the presence or absence of spine. Shell height, shell diameter, aperture diameter and collar height did not differ significantly between the two morphotypes. The number of conical spines varies from 0 to 8. However, the distribution of spine numbers showed two main modes at 0 (spineless form 45.1% of individuals) and 4–6 (38.9%), suggesting the possible existence of two genetically distinct lineages. Spines may have ecological and evolutionary significance. Our results suggested that the spiny and spineless morphotypes of D. tuberspinifera represent either a single variable taxon with different ecotypes or sibling species. Further morphological studies on clonal variations and molecular approaches are needed to clarify if the spineless morph represents an independent species or not. [Copyright &y& Elsevier]

Introduction: Internet use has become an increasingly common leisure time activity among Chinese citizens. The association between Internet use and engagement in leisure activities is especially unclear among China population. This study aims to investigate Internet usage and to determine whether active Internet use is a marker for low or high levels of leisure time activities. Methods/Principal Findings: With the use of a face-to-face structured questionnaire interview, a total of 2,400 respondents who met all screening requirements were surveyed to answer the questions in eight major cities in China. 66.2% (n = 1,589) of all respondents were identified as Internet users. Of these Internet users, 30.0%, 24.1%, 26.4%, and 19.6% were clustered as “informative or instrumental users,” “entertainment users,” “communication users,” and “advanced users,” respectively. Regarding time spent on Internet use in leisure time, more than 96% reported going online in non-work situations, and 26.2% (n = 416) were classified as “heavy Internet users.” A logistic regression analysis revealed that there were significant differences in some leisure activities between non-Internet users and Internet users, with an observed one-unit increase in the leisure time dependence category increasing the probability of engaging in mental or social activities. In contrast, Internet users were less engaged in physical exercise-related activities. In addition, advanced Internet users were generally more active in leisure time activities than non-Internet users and other types of users. Conclusion/Significance: Internet use is one of very common leisure activities in Chinese citizens, and age, gender, income, and education are the key factors affecting Internet access. According to different types of leisure activities, Internet usage has different impacts on leisure activity engagement. High Internet dependence has no significant negative influence on engagement in mental or social leisure activities, but this group respondent tended to be less engaged in physical activities. [ABSTRACT FROM AUTHOR]

Background: To describe the distribution of corneal endothelial cell density (ECD), and to explore its correlation with birth weight (BW), anthropometric parameters, and ocular biometric parameters in Chinese school children., Methods: In the population-based cross-sectional Nanjing Eye Study, children were measured for anthropometric information, for ECD by the noncontact specular microscope and for ocular biometric parameters by the optic low-coherent reflectometer. Data from right eyes were analyzed to illustrate the distribution of ECD and for determining correlated factors with ECD using univariate and multiple linear regression analysis. Comparisons among three different BW groups were performed using a one-way ANOVA analysis followed by the Bonferroni correction for pairwise comparisons., Results: Of 1171 children, the mean (± standard deviation) ECD was 2875.34 ± 195.00 cells/mm 2 . In the Multiple Linear Regression analysis, BW, gender and central corneal thickness were significantly associated with ECD. The ECD increased by 36.16 cells/mm 2 with BW increasing by 1 kg (P = 0.001) and increased by 0.44 cells/mm 2 for every additional 1 mm in central corneal thickness (P = 0.01). The ECD of girls was 54.41 cells/mm 2 higher than boys (P < 0.001). Children born with low BW presented significantly lower ECD than those born with normal BW (P < 0.05) and high BW (P < 0.05). Age and axial length were not significantly associated with ECD (P = 0.06 and P = 0.21, respectively)., Conclusions: In Chinese school children aged 82 to 94 months, the ECD is positively correlated with BW and central corneal thickness, in which BW is a newly identified associated factor. It is like that gender plays an important role in ECD distribution while girls have relatively greater ECD than boys., (© 2022. The Author(s).)

Highlights: [•] We conducted a nation-wide survey on the perceptions and acceptability of HPV vaccination. [•] We found low acceptability of HPV vaccine among parents of young adolescents. [•] Mothers and well educated parents were less likely to accept HPV vaccination. [•] Knowledge of HPV and HPV vaccine was a positive correlate with vaccination acceptability. [•] Local CDC was selected as the most appropriate venue for HPV vaccination. [ABSTRACT FROM AUTHOR]

Purpose: To assess the repeatability and accuracy of optical biometry (Lenstar LS900 optical low-coherence reflectometry [OLCR] and IOLMaster partial coherence interferometry [PCI]) and applanation ultrasound biometry in highly myopic eyes. Setting: Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Guangzhou, China. Design: Comparative evaluation of diagnostic technology. Methods: Biometric measurements were taken in highly myopic subjects with a spherical equivalent (SE) of −6.00 diopters (D) or higher and an axial length (AL) longer than 25.0 mm. Measurements of AL and anterior chamber depth (ACD) obtained by OLCR were compared with those obtained by PCI and applanation A-scan ultrasound. Right eyes were analyzed. Repeatability was evaluated using the coefficient of variation (CoV) and agreement, using Bland-Altman analyses. Results: The mean SE was −11.20 D ± 4.65 (SD). The CoVs for repeated AL measurements using OLCR, PCI, and applanation ultrasound were 0.06%, 0.07%, and 0.20%, respectively. The limits of agreement (LoA) for AL were 0.11 mm between OLCR and PCI, 1.01 mm between OLCR and applanation ultrasound, and 1.03 mm between PCI and ultrasound. The ACD values were 0.29 mm, 0.53 mm, and 0.51 mm, respectively. These repeatability and agreement results were comparable in eyes with extreme myopia (AL ≥27.0 mm) or posterior staphyloma. The mean radius of corneal curvature was similar between OLCR and PCI (7.66 ± 0.24 mm versus 7.64 ± 0.25 mm), with an LoA of 0.12 mm. Conclusion: Optical biometry provided more repeatable and precise measurements of biometric parameters, including AL and ACD, than applanation ultrasound biometry in highly myopic eyes. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]

Objective: To assess associations among outdoor activity, ocular biometric parameters, and myopia among grade 1 and grade 4 primary students in Beijing. Design: School-based, cross-sectional study. Participants: A total of 382 grade 1 and 299 grade 4 children participated in the study. Methods: The children underwent a comprehensive eye examination, including ocular biometry by optical low-coherence reflectometry and noncycloplegic refractometry. Parents and children participated in a detailed interview, including questions on time spent indoors and outdoors. Main Outcome Measures: Factors associated with myopia. Results: The study included 681 children, with 382 (56.1%) students from grade 1 (mean age, 6.3±0.5 years; range, 5–8 years) and 299 students from grade 4 (mean age, 9.4±0.7 years; range, 8–13 years); 370 students (54.3%) lived in the urban region. The mean daily time spent outdoors was 1.6±0.8 hours (range, 0.5–5.1 hours). In multivariate analysis, axial length was significantly associated with older age (P<0.001; standardized β coefficient, 0.28), taller body height (P = 0.001; β, 0.18), maternal myopia (P = 0.03; β, 0.09), and urban region of habitation (P<0.001; β, −0.21), or alternatively to the region of habitation, with less time spent outdoors (P = 0.001; β, −0.16) and more time spent indoors studying (P = 0.02; β, 0.10). The axial length-to-corneal curvature radius ratio was associated with older age, urban region of habitation, maternal and paternal myopia, and paternal level of education. Presence of myopia (defined as refractive error ≤−1 diopters in the right eye) was associated with older age (P<0.001; odds ratio [OR], 1.45; 95% confidence interval [CI], 1.24–1.69), maternal myopia (P<0.001; OR, 2.99; 95% CI, 1.94–5.35), and urban region of habitation (P<0.001; OR, 0.17; 95% CI, 0.11–0.26), or alternatively to the region of habitation, with less time spent outdoors (P<0.001; OR, 0.32; 95% CI, 0.21–0.48) and more time spent indoors studying (P<0.001; OR, 1.38; 95% CI, 1.09–1.75). Conclusions: Less outdoor activity, more indoor studying, older age, maternal myopia, and urban region of habitation were associated with longer ocular axial length and myopia in grade 1 and grade 4 primary school children in Greater Beijing. Remaining outdoors more (e.g., during school) may reduce the high prevalence of myopia in the young generation in Beijing. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. [Copyright &y& Elsevier]

Background: The increase in the prevalence of myopia has become a matter of serious public health concern, and few studies to date have examined the ocular biometric parameters of myopia in young Chinese adults. This study aimed to investigate the longitudinal ocular biometric and refractive development of first-year university students and the influence of near work., Methods: This study included 526 first-year university students from Tianjin Medical University (mean age, 18.34 years; 313 females and 213 males). From 2016 to 2018, participants underwent ocular biometry measurements and subjective refraction annually. Near-work activities such as the use of electronic devices, online games, reading, and writing as well as demographic data were recorded by questionnaires., Results: The prevalence of myopia in this population from 2016 to 2018 was 92.40%, 92.59%, and 92.97%, respectively. Importantly, the prevalence of high myopia increased significantly from 20.91% to 28.33% (P < .001). The spherical equivalent refraction was significantly more myopic by approximately - 0.38 D (from - 4.18 ± 2.44 to - 4.56 ± 2.57 D; P < .001) during the period. The axial length, central corneal thickness, and lens thickness became significantly different (all P < .05), and the axial length significantly increased by 0.12 mm during 2 years (P < .001). Using binary logistic regression analysis, the data indicated that spending more time on online games (odds ratio, 2.09; 95% confidence interval, 1.33-3.29) could speed up the progression of myopia (P < .05)., Conclusions: This study showed that the prevalence of high myopia continued to increase in undergraduate students over 2 years. Baseline myopia correlated with myopic shift, the time spent on online games, and parental myopia were significantly associated with an increase in myopia in these young adult populations., (© 2022. The Author(s).)

Objective: To analyse the morphological characteristics of the ciliary muscle (CM) and to explore its relationship with different ocular biometric parameters in myopic young Chinese adults., Methods: This observational, cross-sectional study included 50 right eyes from 50 myopic adults. The CM area (CMA), CM thickness (CMT) and CM length (CML) were measured using the ArcScan Insight ® 100. CMT was determined at three points: 1.0 mm (CMT-1), 2.0 mm (CMT-2) and 3.0 mm (CMT-3) posterior to the scleral spur. CML was measured on the scleral (CMLs) and vitreous (CMLv) aspects. The spherical equivalent refraction (SER), axial length (AL) and subfoveal choroidal thickness (SFCT) were examined to determine their associations with CM parameters (CMA, CML and CMT)., Results: The mean SER and AL were -4.39 ± 2.29 D and 25.61 ± 1.15 mm, respectively. Compared with the nasal CMA, CML and CMT (CMT-1, CMT-2 and CMT-3) findings, the temporal CM parameters (CMA, CMLs, CMLv, CMT-1, CMT-2 and CMT-3) were found to be significantly thicker (all p < 0.001, except CMLv and CMT-1; p < 0.01). The nasal CMA was associated with the average corneal curvature (r = 0.30, p = 0.03) and SER (r = -0.30, p = 0.04). Nasal and temporal CMT-2 were negatively correlated with SER (r = -0.33 and -0.32, respectively, both p < 0.05). There was no correlation between CM parameters (except nasal CMLs, r = 0.31, p = 0.03) and SFCT, or between CM parameters and either the AL or anterior chamber depth (all p > 0.05)., Conclusion: These results suggest that there is temporal versus nasal asymmetry of the CM. CMA, CMT or CML did not vary with axial growth of the eye. The CM is not simply stretched as the eye elongates in myopic young adults., (© 2022 The Authors Ophthalmic and Physiological Optics © 2022 The College of Optometrists.)

Background: The sense of gain has gradually become the main evaluation index for the effectiveness of China's deepening reform and is affected by many factors. However, there is no relevant research on the sense of gain of health-care reform (SGHR) and its influencing factors. The purpose of this study was to explore the influence of subjective socioeconomic status (SSS) on SGHR and the mediating role of self-rated health (SRH) between them., Methods: Data (25,149 samples total) from China Family Panel Studies (CFPS) in 2018 were included in the analysis. A nonparametric test was used to explore the differences in demographic characteristics of SGHR, and a correlation analysis and mediating effect model were used to explore the influence of SSS on SGHR and the mediating effect of SRH., Results: Demographic characteristics such as age, urban and rural areas, educational background, marriage and choice of medical treatment had significant differences in the distribution of perceived acquisition of medical reform. SSS, SRH and SGHR are statistically positively correlated with each other. SSS has a positive statistical correlation with SGHR, and may have an indirect effect through SRH., Conclusions: SSS is an important predictor of SGHR, and SRH may play a partially mediating role in SGHR., (© 2022. The Author(s).)

Importance: Evidence on the timing of fetal growth alterations associated with gestational diabetes or on the association of the maternal glycemic trajectory with fetal growth during pregnancy remains lacking., Objective: To examine the associations between maternal glucose levels and offspring intrauterine growth., Design, Setting, and Participants: This cohort study used data from 4574 eligible pregnant women and their offspring in the Shanghai Maternal-Child Pairs Cohort collected from April 10, 2016, to April 30, 2018. Group-based trajectory modeling was used to classify fasting plasma glucose levels during pregnancy into 3 glycemic trajectories (trajectory 1, consistently normal glucose levels in all 3 trimesters; trajectory 2, hyperglycemia only in late pregnancy; and trajectory 3, hyperglycemia in all 3 trimesters [ie, consistently high glucose levels]). Statistical analysis was performed from April 25, 2020, to October 1, 2021., Exposures: Gestational diabetes, which was defined using the results of an oral glucose tolerance test., Main Outcomes and Measures: Longitudinal fetal biometrics during gestational weeks 11 to 40 and birth outcomes were obtained from medical records. Pregnancy was partitioned into 3 periods (<24, 24-34, and >34 weeks' gestational age). The differences in offspring growth (log-transformed) and maternal glucose levels were compared using generalized linear mixed models., Results: A total of 4121 pregnant women had oral glucose tolerance test results (mean [SD] age, 28.8 [4.1] years), 3746 of whom had glycemic trajectory data (mean [SD] age, 28.6 [4.1] years); 983 women (23.8%) had gestational diabetes. Throughout the pregnancy period and compared with the women without gestational diabetes or with women in the trajectory 1 group, the fetal biometrics for the women with gestational diabetes or for those in the trajectory 3 group were significantly higher (except for biparietal diameter), with an estimated increase in fetal weight in the group with gestational diabetes (β = 1.82; 95% CI, 1.03-2.61) and in the trajectory 3 group (β = 1.50; 95% CI, 0.54-2.47; P = .002). Fetal biometric alterations among women with gestational diabetes appeared before 24 weeks' gestational age, with neonatal birth weight significantly higher than in the group without gestational diabetes at 40.4 g (95% CI, 9.8-71.1 g) along with an increased risk of large size for gestational age (odds ratio, 1.36; 95% CI, 1.05-1.75) and macrosomia (odds ratio, 1.47; 95% CI, 1.12-1.94). However, pregnant women in the trajectory 2 group manifested significantly reduced fetal biometrics, and abdominal circumference was significantly augmented after 34 weeks' gestational age (increase, β = 1.92; 95% CI, 0.87-2.99)., Conclusions and Relevance: In this cohort study, pregnant women who received a diagnosis of gestational diabetes in midpregnancy or had hyperglycemia during all 3 trimesters showed an association with altered fetal growth patterns, including increased estimated fetal weight that appeared before 24 weeks' gestational age, increased birth weight, and the risk for large size for gestational age and macrosomia.

Objectives To develop and validate new birth-weight prediction models in Chinese pregnant women using fractional thigh volume. Methods Healthy late third-trimester fetuses within 5 days of delivery were prospectively examined using two- (2D) and three- (3D) dimensional ultrasonography. Measurements were performed using 2D ultrasound for standard fetal biometry and 3D ultrasound for fractional thigh volume (TVol) and middle thigh circumference. The intraclass correlation coefficient (ICC) was used to analyze the inter- and intraobserver reliability of the 3D ultrasound measurements of 40 fetuses. Five birth-weight prediction models were developed using linear regression analysis, and these were compared with previously published models in a validation group. Results Of the 290 fetuses studied, 100 were used in the development of prediction models and 190 in the validation of prediction models. The inter- and intraobserver variability for TVol and middle thigh circumference measurements was small (all ICCs ≥ 0.95). The prediction model using TVol, femur length (FL), abdominal circumference (AC) and biparietal diameter (BPD) provided the most precise birth-weight estimation, with a random error of 4.68% and R2 of 0.825. It correctly predicted 69.5 and 95.3% of birth weights to within 5 and 10% of actual birth weight. By comparison, the Hadlock model with standard fetal biometry (BPD, head circumference, AC and FL) gave a random error of 6.41%. The percentage of birth-weight prediction within 5 and 10% of actual birth weight was 46.3 and 82.6%, respectively. Conclusion Consistent with studies on Caucasian populations, a new birth-weight prediction model based on fractional thigh volume, BPD, AC and FL, is reliable during the late third trimester in a Chinese population, and allows better prediction than does the Hadlock model. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article discusses a study aimed at determining the sex of near-threatened Reed Parrotbill Paradoxornis heudei using biometrics and sex ratio variations in Chongming Dongtan Nature Reserve, China. The study analyzed differences in gender morphology and defined sex ratios during the breeding period of unharvested and harvested reedbeds. The study found that Reed Parrotbill has a similar balanced sex ratio as the Vinous-throated Parrotbill P. webbianus.

Abstract: A new species of Laelius (Hymenoptera: Bethylidae) from China is described and illustrated. Biometric measurement data are also included. Laelius jilinensis Lim and S. Lee sp. nov. is characterized by ‘having mandible with four teeth, the propodeal disc with five discal carinae and the pronotum slightly wider than long’ from other congeneric species. A key to the species of the genus Laelius from the Eastern Palaearctic region is also provided. [ABSTRACT FROM AUTHOR]

The article describes the construction and development of new reference charts and equations for fetal biometry in the Hong Kong ethnic Chinese population in comparison with existing references from different populations. The results indicate the development and application of a new set of reference centiles for fetal biometric measurements and equations for clinical use and research in appropriate Chinese groups.