Corneal stress‒strain index in relation to retinal nerve fibre layer thickness among healthy young adults.

BACKGROUND/OBJECTIVES: To determine the relationship between corneal stress-strain index (SSI) and retinal nerve fibre layer (RNFL) thickness. SUBJECTS/METHODS: 1645 healthy university students from a university-based study contributed to the analysis. The RNFL thickness was measured by high-definition optical coherence tomography (HD-OCT), axial length (AL) was measured by IOL Master, and corneal biomechanics including SSI, biomechanical corrected intraocular pressure (bIOP), and central corneal thickness (CCT) were measured by Corvis ST. Multivariate linear regression was performed to evaluate the relationship between the SSI and RNFL thickness after adjusting for potential covariates. RESULTS: The mean age of the participants was 19.0[Formula: see text]0.9 years, and 1132 (68.8%) were women. Lower SSI was significantly associated with thinner RNFL thickness ([Formula: see text]=8.601, 95% confidence interval [CI] 2.999-14.203, [Formula: see text] = 0.003) after adjusting for age, CCT, bIOP, and AL. No significant association between SSI and RNFL was found in men, while the association was significant in women in the fully adjusted model. The association was significant in the nonhigh myopic group ([Formula: see text] for trend = 0.021) but not in the highly myopic group. Eyes with greater bIOP and lower SSI had significantly thinner RNFL thickness. CONCLUSIONS: Eyes with lower SSI had thinner RNFL thickness after adjusting for potential covariates, especially those with higher bIOP. Our findings add novel evidence of the relationship between corneal biomechanics and retinal ganglion cell damage.

Distribution and determinants of corneal volume among healthy young Chinese adults: a cross-sectional study.

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 mm3. 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.

Refractive associations with corneal biomechanical properties among young adults: a population-based Corvis ST study.

PURPOSE: To assess the associations of corneal biomechanical properties as measured by the Corvis ST with refractive errors and ocular biometry in an unselected sample of young adults. METHODS: A total of 1645 healthy university students underwent corneal biomechanical parameters measurement by the Corvis ST. The refractive status of the participants was measured using an autorefractor without cycloplegia. Ocular biometric parameters were measured using the IOL Master. RESULTS: After adjusting for the effect of age, sex, biomechanical-corrected intraocular pressure and central corneal thickness, axial length was significantly associated with A1 velocity (A1v, ß = -10.47), A2 velocity (A2v, ß = 4.66), A2 deflection amplitude (A2DeflA, ß = -6.02), HC deflection amplitude (HC-DeflA, ß = 5.95), HC peak distance (HC-PD, ß = 2.57), deformation amplitude ratio max (DA Rmax, ß = -0.36), Ambrósio's relational thickness to the horizontal profile (ARTh, ß = 0.002). For axial length / corneal radius ratio, only A1v (ß = -2.01), A1 deflection amplitude (A1DeflA, ß = 2.30), HC-DeflA (ß = 1.49), HC-PD (ß = -0.21), DA Rmax (ß = 0.07), stress-strain index (SSI, ß = -0.29), ARTh (ß < 0.001) were significant associates. A1v (ß = 23.18), HC-DeflA (ß = -15.36), HC-PD (ß = 1.27), DA Rmax (ß = -0.66), SSI (ß = 3.53), ARTh (ß = -0.02) were significantly associated with spherical equivalent. CONCLUSION: Myopic eyes were more likely to have more deformable corneas and corneas in high myopia were easier to deform and were even softer compared with those in the mild/moderate myopia.

Refractive Associations With Whole Eye Movement Distance and Time Among Chinese University Students: A Corvis ST Study.

Purpose: Eye movement has been frequently studied in clinical conditions, but the association with myopia has been less explored, especially in population-based samples. The purpose of this study was to assess the associations of eye movement measured by the Corvis ST with refractive status in healthy university students. Methods: A total of 1640 healthy students were included in the study (19.0 ± 0.9 years). Eye movement parameters (whole eye movement [WEM]; whole eye movement time [WEMT]) were measured by the Corvis ST. Spherical equivalent (SE) was measured using an autorefractor without cycloplegia. IOL Master was used to assess axial length (AL). Results: AL was negatively correlated with WEM and WEMT (rWEM = -0.28, rWEMT = -0.08), and SE was positively correlated with WEM and WEMT (rWEM = 0.21, rWEMT = 0.14). For the risk of high myopia, breakpoint analysis and restricted cubic spline model showed that the knots of the significant steep downward trend of WEM and WEMT were 0.27 mm and 20.4 ms, respectively. The piecewise linear regression model revealed a significant correlation between AL, SE, and WEM when the value of WEM was below 0.27 mm. Additionally, when WEMT exceeded 20.4 ms, a significant decrease in AL and an increase in SE were observed with increasing WEMT. Conclusions: A larger distance and longer duration of eye movement were correlated with a lower degree of myopia and shorter AL, and there was a threshold effect. Translational Relevance: The findings might aid in understanding the pathogenesis of myopia and provide a theoretical foundation for clinical diagnosis and prediction.

Identification of high-risk patterns of myopia in Chinese students based on four major behavioral risk factors: a latent class analysis.

BACKGROUND: Myopia is prevalent in children and adolescents. Understanding the effect of multiple behaviors and their latent patterns on ocular biometric parameters may help clinicians and public health practitioners understand the behavioral risk pattern of myopia from a person-centered perspective. The purpose of this study was to identify the patterns of four major behavioral risk factors associated with myopia, including time spent outdoors, digital screen time, sleep duration, and performance of Chinese eye exercises. The study also examined the relationships between these behavioral patterns and myopia as well as ocular biometric parameters in a sample of Chinese college students. METHODS: This study included 2014 students from the Dali University Students Eye Health Study. The average age of the subjects was 19.0 ± 0.9 years old, ranging from 15.7 to 25.1 years old. Each participant's refractive status was measured using an autorefractor without cycloplegia and ocular biometric parameters were measured using an IOL Master. Behavioral risk factors were collected using a pre-designed self-administered questionnaire. Latent class analysis (LCA) was performed to identify cluster patterns of various behaviors. RESULTS: The prevalence of myopia was 91.8% in this population. The 2-class model was selected for the LCA based on goodness-of-fit evaluation metrics. Among the overall study sample, 41.1% and 58.9% were assigned into the high-risk and low-risk class, respectively. The risk of myopia [odds ratio (OR) = 2.12, 95% confidence interval (CI) = 1.52-3.14], high myopia (OR = 1.43, 95% CI = 1.14-1.78) and axial length/corneal radius (AL/CR) ratio of more than 3.0 (OR = 1.82, 95% CI = 1.22-2.72) were significantly higher in the high-risk compared with low-risk class. CONCLUSIONS: Chinese university students showed differential risks of myopia and could be subdivided into high- and low-risk clusters based on four behavioral variables.

Associations between sleep characteristics, chronotype and body mass index among Chinese college freshmen.

Research indicates that sleep problem is a behavioral risk factor of obesity. However, few research have applied a multi-dimensional approach to investigate the relationship between sleep health and adiposity. Therefore, the current study aimed to examine the associations of sleep characteristics (duration, quality) and chronotype with overweight/obesity as measured by body mass index. Data were obtained from 2014 college students from the Dali University in the Yunnan province of China in the year 2021. Sleep characteristics and chronotype were measured using self-reported questionnaires. The presence of overweight/obesity was assessed by anthropometric measurements. Multiple logistic regression models and restricted cubic spline hazard models were established to examine associations between sleep characteristics, chronotype and adiposity. After adjusting for demographic characteristics and other obesity-related behavioral risk factors, evening type was positively associated with overweight/obesity, and an L-shaped dose-effect relationship was observed between chronotype scores and the presence of overweight/obesity. However, sleep duration and quality were not associated with the presence of overweight/obesity in the logistic regression models and restrictive cubic splines models. This study indicated that Chinese college students who had the evening chronotype were more likely to be affected by overweight/obesity. Chronotype as an important dimension of sleep health should be incorporated in obesity intervention programs.

Smoking, alcohol consumption and corneal biomechanical parameters among Chinese university students.

BACKGROUND/OBJECTIVES: Smoking and alcohol consumption are important risk factors for several ocular disorders, but their effects on corneal biomechanics remain unclear. Our study aims to explore the association between smoking and alcohol consumption with corneal biomechanical parameters measured by Corvis-ST (CST) among university students. SUBJECTS/METHODS: A total of 1645 healthy university students from a university-based study were included, and all participants underwent corneal biomechanical parameters measurement by CST. We selected 10 reliable parameters that can reflect the corneal deformation response. All participants had a standardised interview to determine their smoking and alcohol consumption status. RESULTS: The mean age of the participants was 19.0 ± 0.9 years, and 1132 (68.8%) were women. Smoking was significantly associated with stiffer corneas. Smokers showed significantly slower second applanation velocity (A2v) (ß = 0.007 m/s, 95% confidence interval 0.001 to 0.014, P = 0.032) and lower integrated radius (IR) (ß = -0.214 mm-1, 95% confidence interval -0.420 to -0.007, P = 0.043) than non-smokers after adjusting for age, gender, eye-rubbing, myopia, and body mass index (BMI). Smokers with BMI no less than 24.0 showed slower A2v and lower IR. Alcohol consumption and passive smoking were found no significant association with corneal biomechanics. CONCLUSION: Smokers had less deformable corneas, especially those with BMI no less than 24.0. Our findings provide new evidence for the association between smoking and ocular disorders associated with corneal biomechanics like glaucoma.

Dermoscopy in China: current status and future prospective.

OBJECTIVE: Dermoscopy is a useful technique for improving the diagnostic accuracy of various types of skin disorders. In China, dermoscopy has been widely accepted, and domestic researchers have made tremendous progress in the field of dermoscopy. The main purpose of this review is to summarize the current status of dermoscopy in China and identify its future directions. DATA SOURCES: Articles included in this review were obtained by searching the following databases: Wanfang, China National Knowledge Infrastructure, PubMed, and the Web of Science. We focused on research published before 2019 with keywords including dermoscopy, dermoscopic, dermoscope and trichoscopy. STUDY SELECTION: A total of 50 studies were selected. Of these studies, 20 studies were in Chinese and 30 in English, research samples of all the studies were collected from Chinese populations. RESULTS: Since 2000, more than 380 articles about dermoscopy have been published in domestic or foreign journals. Dermoscopy can improve the diagnostic accuracy of neoplastic diseases, evaluating the therapeutic effect of treatment, and determining the treatment endpoint, and it can also assist in the differential diagnosis of inflammatory diseases and in the assessment of the severity of the disease. In addition, researches about the applications of dermoscopy during surgical treatment have been published. Training courses aiming to improve the diagnostic ability of dermatologists, either face-to-face or online, have been offered. The Chinese Skin Image Database, launched in 2017 as a work platform for dermatologists, has promoted the development of dermoscopy in China. Computer-aided diagnostic systems based on the Chinese population are ready for use. In the future, cooperation, resource sharing, talent development, image management, and computer-aided diagnosis will be important directions for the development of dermoscopy in China. CONCLUSION: Dermoscopy has been widely used and developed in China, however, it still needs to address more challenges in the future.

A new diagnostic model of primary open angle glaucoma based on FD-OCT parameters.

AIM: To build a clinical diagnostic model of primary open angle glaucoma (POAG) using the normal probability chart of frequency-domain optical coherence tomography (FD-OCT). METHODS: This is a cross-sectional study. Total 133 eyes from 133 healthy subjects and 99 eyes from 99 early POAG patients were included in the study. The retinal nerve fibre layer (RNFL) thickness parameters of optic nerve head (ONH) and RNFL3.45 scan were measured in one randomly selected eye of each subject using RTVue-100 FD-OCT. Then, we used these parameters to establish the diagnostic models. Four different diagnostic models based on two different area partition strategies on ONH and RNFL3.45 parameters, including ONH traditional area partition model (ONH-T), ONH new area partition model (ONH-N), RNFL3.45 traditional area partition model (RNFL3.45-T) and RNFL3.45 new area partition model (RNFL3.45-N), were built and tested by cross-validation. RESULTS: The new area partition models had higher area under the receiver operating characteristic (AROC; ONH-N: 0.990; RNFL3.45-N: 0.939) than corresponding traditional area partition models (ONH-T: 0.979; RNFL3.45-T: 0.881). There was no statistical difference among AROC of ONH-T, ONH-N, and RNFL3.45-N. Nevertheless, ONH-N was the simplest model. CONCLUSION: The new area partition models had higher diagnostic accuracy than corresponding traditional area partition models, which can improve the diagnostic ability of early POAG. In particular, the simplest ONH-N diagnostic model may be convenient for clinical application.

Systematic identification of flavonols, flavonol glycosides, triterpene and siraitic acid glycosides from Siraitia grosvenorii using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry combined with a screening strategy.

The fruits of Siraitia grosvenorii are considered to be health-promoting because of the diversity of their bioactive ingredients. In the present study, a screening method, using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC-Q-TOF-MS) combined with a screening strategy, has been established. The technology was used to systematically screening the targeted metabolites, primarily from the complex matrix of S. grosvenorii. The compounds were then identified by their exact masses and characteristic fragment ions, in comparison with the fragmentation behaviors of 19 references. Finally, 122 compounds, including 53 flavonols and flavonol glycosides, 59 triterpene glycosides and 10 siraitic acid glycosides, were screened and identified in 10-, 50- and 80-day fruits, roots, stems and leaves of S. grosvenorii. 98 of them were reported for the first time. Additionally, the distribution of all identified components in different parts of the plant was determined and metabolic networks for flavonol and triterpene glycosides were proposed.

[Impurity analysis and quality evaluation for commercial levofloxacin formulations using LC-MS/MS method].

The study aims to develop a rapid, specific and sensitive method for quantitative analysis of trace impurities in levofloxacin formulation using LC-MS/MS. The quality of the different formulations from 19 plants was evaluated in the contents of the impurities. The results indicated that there were 5 impurities in the samples, and the content was different in the products with same formulation by different plants. The products of 3 plants were in good quality with impurities level under 0.01%. Levofloxacin N(4')-methyl quaternary impurity was first reported as the formulation impurity. The impurities were tightly correlated to the reservation of drug, process control of formulation and storage during transportation. The results suggest that our method is sensitive and specific to detect the trace impurities in formulation, and can be used to monitor the quality of commercial drug product.

Proteins interacting with mitochondrial ATP-dependent Lon protease (MAP1) in Magnaporthe oryzae are involved in rice blast disease.

The ATP-dependent Lon protease is involved in many physiological processes. In bacteria, Lon regulates pathogenesis and, in yeast, Lon protects mitochondia from oxidative damage. However, little is known about Lon in fungal phytopathogens. MAP1, a homologue of Lon in Magnaporthe oryzae, was recently identified to be important for stress resistance and pathogenesis. Here, we focus on a novel pathogenic pathway mediated by MAP1. Based on an interaction system between rice and a tandem affinity purification (TAP)-tagged MAP1 complementation strain, we identified 23 novel fungal proteins from infected leaves using a TAP approach with mass spectrometry, and confirmed that 14 of these proteins physically interact with MAP1 in vivo. Among these 14 proteins, 11 candidates, presumably localized to the mitochondria, were biochemically determined to be substrates of MAP1 hydrolysis. Deletion mutants were created and functionally analysed to further confirm the involvement of these proteins in pathogenesis. The results indicated that all mutants showed reduced conidiation and sensitivity to hydrogen peroxide. Appressorial formations were not affected, although conidia from certain mutants were morphologically altered. In addition, virulence was reduced in four mutants, enhanced (with lesions forming earlier) in two mutants and remained unchanged in one mutant. Together with the known virulence-related proteins alternative oxidase and enoyl-CoA hydratase, we propose that most of the Lon-interacting proteins are involved in the pathogenic regulation pathway mediated by MAP1 in M. oryzae. Perturbation of this pathway may represent an effective approach for the inhibition of rice blast disease.

An integrated approach for detection and characterization of the trace impurities in levofloxacin using liquid chromatography-tandem mass spectrometry.

RATIONALE: Impurity analysis plays an important role to guarantee the quality and safety of pharmaceuticals. However, identification of impurities remains challenging, especially for those unknown or at trace levels. We present an integrated approach to detect and characterize the trace impurities in drugs. METHODS: Based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), an approach integrating automatic impurity screening method using multiple mass defect filters (MMDFs) and background subtraction (BS) was developed. This approach was used to acquire the structural and semi-quantitative information in a single sample run, and even to discover the impurity signals submerged by background and drug ions. This approach was illustrated by the comprehensive impurity analysis of levofloxacin. RESULTS: This approach was sensitive to detect impurities at the level of 0.02% with respect to levofloxacin concentration. Nineteen impurities were detected, fourteen of which were structurally characterized and eight impurities were reported for the first time. Impurity profiles of levofloxacin drug substances and degradation samples were obtained reliably. A plausible degradation pathway of levofloxacin was proposed including descarboxyl reaction under acid, piperazinyl ring cleavage degradation under light, and N-oxidation under oxidative condition. CONCLUSIONS: The generic approach integrating LC-MS/MS and an automatic impurity screening method was developed for the detection, characterization and monitoring of impurities, especially those unknown or at trace levels. This approach was demonstrated to be rapid, sensitive and automatic for impurity profiling of drugs.

[Rapid screening and quality evaluation for the harmful substance 5-hydroxymethyl furfural in commercially available traditional Chinese medicine injection using LC-MS/MS method].

To screen the harmful substance 5-hydroxymethyl furfural content in commercially available traditional Chinese medicine injection which are commonly used, and to preliminarily evaluate the quality of these injections, 5-hydroxymethyl furfural was taken as an index. The contents of 5-hydroxymethyl furfural in 56 samples which consist of 23 kinds of traditional Chinese medicine injections and glucose injection were determined using LC-MS/MS, and 5-hydroxymethyl furfural was detected in 52 of these samples. The minimal content was 0.0038 microg x L(-1) and the maximum content was 1420 microg x mL(-1). The contents of 5-hydroxymethyl furfural were significantly different in traditional Chinese medicine injection which came from different kinds, manufacturers or batches. The results showed the quality difference of commercially available traditional Chinese medicine injection is significant taking 5-hydroxymethyl furfural content as assessment index. More attention should be paid to the safety of 5-hydroxymethyl furfural in traditional Chinese medicine injection, and unified limitation standard should be set to improve medication safety of traditional Chinese medicine injection.