AIM:To investigate the prevalence of visual impairment and its correction status among junior high school students in Xi'an, so as to provide evidence for the development of targeted myopia prevention and control strategies.METHODS: A stratified cluster sampling design was adopted. From March to May 2025, students in grades 7-9 were recruited from three schools in Xi'an, Shaanxi Province, China: Dongfang Middle School, the Middle School Attached to Xi'an University of Technology, and the Xingqing Campus of the High School Affiliated to Xi'an Jiaotong University. In total, 3 974 students were invited, including 1 726 in grade 7, 1 206 in grade 8, and 1 042 in grade 9. The visual acuity was measured monocularly using a 5 m standard logarithmic visual acuity chart, with the fellow eye occluded; the line corresponding to the smallest optotype that could be correctly identified was recorded as the visual acuity value. Non-cycloplegic autorefraction was performed with a desktop autorefractor to obtain spherical equivalent(SE)values for refractive error screening.RESULTS: This study initially included 3 974 students, of whom 32 did not participate in the vision test, resulting in 3 942 students being included in the final analysis. Among them, 3 067(77.80%)were identified with poor vision. The prevalence of myopia was 81.47%(1 746)in males and 87.55%(1 575)in females(P<0.01). A stratified analysis by grade showed myopia rates of 81.72%(1 386)in junior grade one, 84.47%(1 017)in junior grade two, and 88.10%(918)in junior grade three, demonstrating a significant upward trend with increasing grade level(χ2=19.8484, P<0.01). Among the 3 321 myopic students, 2 287 adopted corrective measures. The rates of full correction, under-correction, and non-correction among all myopic students were 48.15%(1 599), 20.71%(688), and 31.14%(1 034), respectively. The rate of non-correction was significantly higher in male students than in females(32.70% vs 29.40%, χ2=4.2222, P<0.05).CONCLUSION: The findings indicate a high prevalence of visual impairment among junior high school students in Xi'an, coupled with suboptimal spectacle-wearing and full-correction rates. There is an urgent need for collaborative efforts across society, schools, and families to implement effective interventions to slow the onset and progression of myopia in this population.

ObjectiveTo investigate the dynamic trajectories of prognostic scores and key clinical indicators in hepatitis B virus-related acute-on-chronic liver failure （HBV-ACLF） patients without liver cirrhosis， to clarify their association with outcomes， and to provide new evidence for individualized prognostic assessment. MethodsA prospective study was conducted for the data of 154 non-cirrhotic HBV-ACLF patients who attended Beijing YouAn Hospital of Capital Medical University from January 2016 to December 2023， including prognostic scores and key biochemical indicators on Days 3， 7， 14， 21， and 28 of the disease course. According to the outcome of patients at 1 year， they were divided into death/liver transplantation group with 43 patients， liver cirrhosis group with 23 patients， and non-liver cirrhosis group with 88 patients， and the trajectory heterogeneity of different outcome subgroups was analyzed. A one-way analysis of variance was used for comparison of normally distributed continuous data among the three groups； the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data among the three groups； the Wilcoxon test was used between two groups. the chi-square test was used for comparison of categorical data between groups. The mean and its 95% confidence interval （CI） were calculated for each indicator at difference time points； the linear interpolation method was used to connect the means at adjacent time points and construct the group-specific longitudinal trend curve； the 95%CI was visualized using the semi-transparent ribbon area， with the transparency parameter （α=0.2） optimized to enhance the visual discrimination of overlapping intervals across multiple groups. A linear mixed-effects model was used to compare the longitudinal changing trend of each indicator between the patients with different outcomes； likelihood ratio was used to evaluate the significance of the interaction effect between time and group， and in case of the significant interaction effect， the slope based on the estimated marginal mean was used for comparison between two groups. ResultsThere were significant differences between the three groups in the incidence rates of ascites and grade Ⅲ — Ⅳ hepatic encephalopathy， MELD score， MELD-Na score， CLIF-C ACLF score， COSSH-ACLF Ⅱ score， total bilirubin （TBil）， international normalized ratio （INR）， alpha-fetoprotein， blood sodium， alanine aminotransferase， and procalcitonin at the baseline（all P0.05）. The analysis of dynamic trajectories showed that the death/liver transplantation group had high levels of prognostic scores and the biochemical parameters of TBil and INR （TBil400 μmol/L， INR2.5）， as well as a low level of platelet count （PLT） （100×10⁹/L）. The non-liver cirrhosis group had rapid improvements in indicators， with TBil200 μmol/L， INR1.5， and PLT100×10⁹/L by day 28， while the liver cirrhosis group showed a trend of recovery， with TBil200 μmol/L， INR2.0， and PLT 100×10⁹/L on day 28， with significant global heterogeneity in the temporal trends of the above indicators across the three groups （all P0.01）. ConclusionDynamic monitoring of prognostic scores and key clinical indicators can effectively stratify the 1-year outcomes of non-cirrhotic patients with HBV-ACLF. Patients with poor prognosis were typically characterized by INR 2.5 and TBil 400 μmol/L. Among those who survived beyond 1 year， individuals who subsequently progressed to cirrhosis were frequently identified by the presence of INR 1.5， TBil 200 μmol/L， and PLT 100×10⁹/L at day 28.