AIM: To investigate variation patterns of corneal biomechanical parameters and binocular symmetry among children of different genders aged 8-16 years.METHODS:A retrospective study was conducted, and children who underwent optometric examinations at the ophthalmology department of our hospital were enrolled between January 2022 and December 2024. Measurements included the flat keratometry(K1), steep keratometry(K2), and mean curvature(Km)of the anterior corneal surface, horizontal visible iris diameter(HVID), central corneal thickness(CCT), corneal endothelial cell density(CECD), average cell size(ACS), coefficient of variation(CV), and hexagonality(HEX). Corneal parameters and binocular differences were compared between genders and across age groups.RESULTS:A total of 621 children(1 242 eyes)were enrolled in this study, including 284 males(568 eyes), 337 females(674 eyes), 528 children aged 8-12 years(1 056 eyes), and 93 children aged 13-16 years(186 eyes). In children aged 8-16 years, the K1, K2, Km and CV of both eyes, as well as the interocular CCT differences in boys were significantly lower than those in girls(all P<0.05), while the HVID and HEX of both eyes, as well as the CCT of the left eye in boys were significantly higher than those in girls(all P<0.05). Children aged 8-12 years had significantly higher K1, Km, CECD and HEX in both eyes, and significantly lower ACS in both eyes than those aged 13-16 years(all P<0.05). K1, K2, Km, CECD and HEX in both eyes were negatively correlated with age(P<0.05); ACS in both eyes was positively correlated with age(P<0.001); K1 and Km of the right eye were positively correlated with the CECD of the right eye(P<0.05), and K1 and CCT of the left eye were positively correlated with the CECD of the left eye(P<0.05).CONCLUSION:Significant gender differences exist in corneal parameters among children aged 8 to 16 years, while binocular symmetry remained stable.

Alzheimer disease(AD)is a neurological disease characterized by cognitive decline.AD continuum refers to the dynamic development progression from early pathological changes to obvious clinical symptoms,covering the continuous spectrum of subjective cognition decline(SCD)stage,mild cognitive impairment(MCI)stage and dementia stage.As one of the key brain regions involved in early stage,hippocampus(HP)in AD continuum is closely related to the progression of disease.MRI has been widely used in the study of HP in the AD continuum.The progresses in structural and functional MRI research of HP changes in AD continuum were reviewed in this article.

Objective:To evaluate the incidence and frequency of inappropriate shocks caused by defibrillation lead failure in patients with implantable cardioverter-defibrillators (ICD), and to explore methods for reducing the incidence and frequency of such inappropriate shocks.Methods:This was a single-center retrospective study involving patients treated for defibrillation lead failures at Peking University People′s Hospital between March 2015 and May 2024. Patients were divided into an alarm function group and a non-alarm function group based on whether their ICDs were equipped with lead alarm functions. Clinical data, lead data, and the incidence and frequency of inappropriate shocks were collected and compared between the two groups. A multivariate logistic regression model was used to analyze factors influencing the incidence and frequency of inappropriate ICD shocks. Kaplan-Meier survival curves were plotted to compare the trends in the incidence and frequency of inappropriate shocks over time since ICD implantation between the two groups.Results:A total of 59 patients were enrolled, with a age of (56.7±15.2) years, including 42 males (71%). The lifespan of the failed leads in the entire cohort was 64.0 (36.0, 96.0) months. There were 26 patients in the alarm function group and 33 in the non-alarm function group. The most common manifestations of lead failure were oversensing (85%, 50/59) and abnormal pacing impedance (42%, 25/59). A total of 33 patients (56%, 33/59) experienced inappropriate shock therapy, with an average of 27.3 shocks per patient. The frequency of inappropriate ICD shocks in the non-alarm function group was higher than that in the alarm function group (25.0 (10.0, 60.0) times/year vs. 5.0 (2.8, 7.8) times/year, P=0.001). Multivariate logistic regression analysis showed that oversensing ( OR=2.057, 95% CI 1.125-6.763, P=0.019) was an influencing factor for incidence of inappropriate shocks, while the lead alert function ( OR=0.062, 95% CI 0.005-0.719, P=0.001) was a factor influencing the frequency of inappropriate shocks. Kaplan-Meier survival analysis revealed that the incidence and frequency of inappropriate shocks increased with the duration of ICD implantation in both groups, but the differences were not statistically significant (incidence: log-rank P=0.908; frequency: log-rank P=0.767). Conclusion:The lead alert function can reduce the frequency of inappropriate shocks caused by lead failure.

Alzheimer's disease(AD),a neurodegenerative disorder,manifests pathological changes in the brain even during the asymptomatic stage.As the pathological burden intensifies,patients experience functional decline in multiple cognitive domains,including memory,language,spatial perception,executive function,and calculation,and may also exhibit emotional abnormalities.Once AD progresses,treatment becomes extremely chal-lenging.Therefore,early diagnosis and accurate prediction of disease conversion are core tasks in the prevention and treatment of AD,and they are also urgent scientific research challenges to be overcome.Deep learning(DL)models demonstrate considerable advantages in the diagnosis,prediction,classification,and feature extraction of AD,offering new hope for solving this challenging problem.This research commences with a concise introduction to the outcomes of AD and the fundamental knowledge of deep learning.Subsequently,it offers an overview of the imaging studies on the utilization of deep learning for predicting disease transformation from two perspectives.Firstly,it systematically summarizes the existing DL models that have demonstrated innovation in the classification and prediction performance of AD.Secondly,it provides a comprehensive outline of the DL fusion models applied to the diagnosis,classification,and prediction of AD.Finally,this paper expounds upon the impending challenges in the research of this domain.This article demonstrates that deep learning models is cutting-edge trends in the ex-ploration of AD research.

Alzheimer disease(AD)is a neurological disease characterized by cognitive decline.AD continuum refers to the dynamic development progression from early pathological changes to obvious clinical symptoms,covering the continuous spectrum of subjective cognition decline(SCD)stage,mild cognitive impairment(MCI)stage and dementia stage.As one of the key brain regions involved in early stage,hippocampus(HP)in AD continuum is closely related to the progression of disease.MRI has been widely used in the study of HP in the AD continuum.The progresses in structural and functional MRI research of HP changes in AD continuum were reviewed in this article.

Objective:To evaluate the clinical feasibility of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation following transvenous lead extraction (TLE).Methods:This was a retrospective study. Consecutive patients who underwent S-ICD implantation at Peking University People′s Hospital between June 2015 and October 2023 were enrolled. Patients were divided into the TLE group and the newly implanted group based on whether they received TLE prior to S-ICD implantation. Baseline characteristics, S-ICD indication, defibrillation threshold test results, complications, and postoperative follow-up data were collected and compared between the two groups.Results:A total of 27 patients were included, aged (49.2±14.2) years, including 19 males. There were 12 patients in the TLE group and 15 in the newly implanted group. Compared with the TLE group, patients in the newly implanted group were younger ((43.3±13.7) years vs. (55.6±12.0) years, P=0.013). The main S-ICD indication in the TLE group was high infection risk (9/12), whereas in the newly implanted group it was younger age (11/15). All patients underwent successful S-ICD implantation, with 18 patients completing defibrillation threshold testing (all successful). Additionally, the TLE group had longer follow-up duration than the newly implanted group (42 (19, 60) months vs. 12 (3, 28) months, P=0.001). No complications or deaths occurred during follow-up, with normal device function in both groups. A total of 17 ventricular tachycardia or fibrillation events were recorded, of which 7 met defibrillation criteria and all received effective therapy. Conclusion:S-ICD demonstrates safety and efficacy as a therapeutic option for patients after TLE, with comparable device functionality and follow-up outcomes to patients with newly implanted S-ICD.

Objective:To evaluate the incidence and frequency of inappropriate shocks caused by defibrillation lead failure in patients with implantable cardioverter-defibrillators (ICD), and to explore methods for reducing the incidence and frequency of such inappropriate shocks.Methods:This was a single-center retrospective study involving patients treated for defibrillation lead failures at Peking University People′s Hospital between March 2015 and May 2024. Patients were divided into an alarm function group and a non-alarm function group based on whether their ICDs were equipped with lead alarm functions. Clinical data, lead data, and the incidence and frequency of inappropriate shocks were collected and compared between the two groups. A multivariate logistic regression model was used to analyze factors influencing the incidence and frequency of inappropriate ICD shocks. Kaplan-Meier survival curves were plotted to compare the trends in the incidence and frequency of inappropriate shocks over time since ICD implantation between the two groups.Results:A total of 59 patients were enrolled, with a age of (56.7±15.2) years, including 42 males (71%). The lifespan of the failed leads in the entire cohort was 64.0 (36.0, 96.0) months. There were 26 patients in the alarm function group and 33 in the non-alarm function group. The most common manifestations of lead failure were oversensing (85%, 50/59) and abnormal pacing impedance (42%, 25/59). A total of 33 patients (56%, 33/59) experienced inappropriate shock therapy, with an average of 27.3 shocks per patient. The frequency of inappropriate ICD shocks in the non-alarm function group was higher than that in the alarm function group (25.0 (10.0, 60.0) times/year vs. 5.0 (2.8, 7.8) times/year, P=0.001). Multivariate logistic regression analysis showed that oversensing ( OR=2.057, 95% CI 1.125-6.763, P=0.019) was an influencing factor for incidence of inappropriate shocks, while the lead alert function ( OR=0.062, 95% CI 0.005-0.719, P=0.001) was a factor influencing the frequency of inappropriate shocks. Kaplan-Meier survival analysis revealed that the incidence and frequency of inappropriate shocks increased with the duration of ICD implantation in both groups, but the differences were not statistically significant (incidence: log-rank P=0.908; frequency: log-rank P=0.767). Conclusion:The lead alert function can reduce the frequency of inappropriate shocks caused by lead failure.

Objectives:To analyze the clinical characteristics,strategies,success and complication rates of lead extraction and re-implantation during the upgrade of cardiovascular implantable electronic devices(CIED)in non-infectious patients.Methods:This retrospective study collected and analyzed the baseline clinical data and surgical data of 66 non-infected patients who had their existing CIEDs(including cardiac pacemaker,implantable cardioverter defibrillator[ICD],cardiac resynchronization therapy pacemaker[CRT-P])upgraded to ICD or CRT-P or cardiac resynchronization therapy defibrillator(CRT-D)or subcutaneous implantable cardioverter defibrillator(S-ICD)in Peking University People's Hospital from March 2018 to March 2024.We analyzed the strategies of lead extraction and reimplantation as well as the operation success rate and complication rate.Results:Among the 66 patients,preoperative imaging revealed that 12 patients(18.2%)had severe stenosis/occlusion of the venous access route,with lead wear/perforation in 26 patients(39.4%).32 patients(48.5%)underwent transvenous lead extraction(TLE),of which all leads were removed in 27 patients(84.4%),and only non-functional leads were removed in 5 patients(15.6%).The success rate of the TLE procedure was 100%and no complication occurred.Among the 66 patients,functional leads retained and new leads were implanted on the same side in 28 patients(42.4%),all leads were removed and new leads were reimplanted on the opposite side in 22 patients(33.3%),only non-functional leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),all leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),and 6 patients(9.1%)had the leads abandoned and then were re-implanled.The success rate of the upgrade surgery was 100%,no complications were reported.Conclusions:When the existing CIEDs(including cardiac pacemaker,ICD,CRT-P)of non-infected patients are upgraded to ICD,CRT-P,CRT-D or S-ICD,lead extraction and reimplantation are safe and feasible,and reimplantation can be performed on the ipsilateral or contralateral side.

Objective:To screen the risk factors for non-complete procedural success of transvenous lead extraction(TLE),and to establish a prediction model based on the results and evaluate its predictive efficacy.Methods:A total of 1 029 patients who underwent TLE in Peking University People's Hospital from January 2014 to December 2020 were enrolled and divided into training set(n=720)and validation set(n=309)using the random number method.There were no statistically significant differences among the variables in the training set and the validation set.The training set was divided into the complete procedural success(CPS)group(n=664)and the non-CPS group(n=56).Univariate analysis was employed to screen the relevant indicators of non-CPS,followed by binary logistic regression analysis to identify the independent risk factors of non-CPS.Subsequently,a predictive model and nomogram were constructed.The receiver operating characteristic(ROC)curve analysis was applied to evaluate the ability of the model to distinguish non-CPS from TLE patients in the training set and validation set.The Hosmer-Lemeshow goodness-of-fit test was used to assess the consistency between the predicted risk and the actual risk of the model.Results:Univariate analysis showed that the relevant variables with P<0.1 including the age at the first implantation of the lead,the number of leads extracted,the oldest dwell time of lead extracted,the presence of abandoned leads,non-manual traction for lead extracted,the number of extracted leads>3,bilateral lead implantation,and the indications for TLE.The binary logistic regression analysis revealed that the presence of abandoned leads(OR=2.252,95%CI:1.111-4.564,P=0.024),the oldest dwell time of the extracted leads(OR=1.009,95%CI:1.005-1.012,P<0.001),and the number of extracted leads>3(OR=3.177,95%CI:1.306-7.733,P=0.011)were independent risk factors for non-CPS of TLE.ROC curve analysis revealed that the area under the ROC curve(AUC)of the training set was 0.80(95%CI:0.75-0.85,P<0.001).The AUC of the validation set was 0.81(95%CI:0.72-0.90,P<0.001).The Hosmer-Lemeshow goodness-of-fit test indicated that the P values of both the training set(P=0.089)and the validation set(P=0.136)were greater than 0.05.Conclusions:The presence of abandoned leads,the oldest dwell time of lead extracted,and the number of extracted leads>3 are independent risk factors for non-CPS in patients undergoing TLE.The nomogram model based on the above factors has satisfactory predictive ability.