Oxidative stress is thought to be associated with many common ophthalmic diseases.Recently studies showed that hydrogen is an antioxidant,and it can selectively reduce the hydroxyl radicals and therefore is used to the prevention and treatment of many diseases,such as retinal neovascularization disease,diabetic retinopathy,retinal ischemia-reperfusion injury,retinal light-injury,etc.Also,hydrogen has a small molecular weight and good water-and lipid-solubility,so it can diffuse freely through the cell membrane toward organelles like mitochondria to exert its treating effect.The research progresses in the application of hydrogen in ophthalmology were summarized.

Objective To determine whether the candidates who were disqualified for having phoria or tropia in People′s Liberation Army Air Force ( PLAAF) medical selection of flying cadets are qualified or not according to United States Air Force ( USAF) Medical Standards Directory , and to raise suggestions on revising PLAAF medical standards . Methods All the candidates who had participated in the final medical selection of flying cadets were reevaluated and determined as qualified or not according to USAF Medical Standards Directory .Results There was a marked difference between disqualification rates of PLAAF and USAF .13.87%of the candidates who were regerded as disqualified by PLAAF standards were qualified according to USAF Medical Standards Directory .These cadets might be eliminated by mistake . Conclusion The standard on heterophonies of the PLAAF is more stringent than that of the USAF .We shoucd revise PLAAF standards using USAF standards for reference .

The global prevalence of myopia is increasing year by year, leading to many ocular health issues and social problems. In recent years, it has been confirmed that peripheral defocus is closely related to the occurrence and development of myopia. Alteration of the state of peripheral defocus can significantly influence the progression of myopia and emmetropization, but the exact mechanisms are still unclear. At present, there is no method that can completely control myopia. Nowadays, the main controlling methods, including orthokeratology lens, peripheral defocus lens and multi-focal soft lens, have been confirmed to be closely related to peripheral defocus. In this paper, we will review and summarize the development and effect of these peripheral defocus relating control methods. In addition, the researches on the related mechanisms of peripheral retinal defocus and myopia prevention and control at home and abroad are reviewed, as well as the potential mechanisms of peripheral defocus, with a view to further improving the controlling effects of existing methods, developing new prevention and control methods and reducing the incidence and progression of myopia.

Objective To retrospectively investigate and analyze the specially permitted aeromedical evaluation results of overage military flying personnel,in order to provide references for health management and related evaluation methods improvement.Methods The clinical data and evaluation results of overage flying personnel were collected from 2012 to 2023.Disease spectrum was analyzed,and qualified rates among different airplane types and aviation duties were compared.Results 79.57%of the 509 flying personnel were detected with diseases,and the top ten were hyperlipidemia,fatty liver,thyroid nodule,renal cyst,hepatic cyst,gallbladder polyps,hyperuricemia,carotid artery arteriosclerosis,hypertension and hepatic hemangioma.96.08%of the personnel were qualified to continue flying,1.96%were disqualified and 1.96%were temporarily disqualified.The qualified rates among different airplane types and aviation duties were not significantly different(P?>?0.05).Conclusion Overage military flying personnel could apply for specially permitted aeromedical evaluation to extend their flying lifespan.Attention should be paid to metabolic and cardiovascular diseases in aeromedical support and evaluation for these experienced flying personnel.

Objective To investigate the accuracy and feasibility of shear wave elastography(SWE)combined with superb microvascular imaging(SMI)for the differential diagnosis of benign and malignant thyroid nodules.Methods A total of 190 patients with thyroid nodu-les detected in the Ultrasound Department of our hospital from January 2021 to December 2022 who underwent ultrasound-guided fine-needle aspiration biopsy or exhibited postoperative histopathological improvement were selected as the study subjects.Among them,a total of 224 thyroid nodules(74 benign and 150 malignant nodules)were detected,all of whom underwent thyroid ultrasonography,SWE,and SMI.The parameters related to the Young's modulus of the tissue as well as the condition of fine blood flow and perforating vessels were calculated.Using histopathological results as the gold standard to construct receiver operating characteristic(ROC)curves,observe the effectiveness of SWE combined with SMI in the differential diagnosis of thyroid nodules,and compare the efficacy of different examination methods in the diagnosis of thyroid nodules.Results There were significant differences in the internal composition,echo,margin,cal-cification,and aspect ratio between the benign and malignant thyroid nodules(all P<0.05);however,there was no significant difference in the average diameter of the benign and malignant nodules(P>0.05).There were statistically significant differences in maximum elas-ticity,mean elasticity,elasticity ratio,microvascular score,peak shear wave velocity,and average shear wave velocity between the benign and malignant thyroid nodules(all P<0.05).The ROC curve showed that the area under the curve of the maximum elastic value was the highest,while the optimal diagnostic threshold was 29.52 kPa.The optimal diagnostic threshold for the microvascular flow score was 2.3 points.In terms of diagnostic efficacy,SWE combined with SMI showed the highest sensitivity(94.67%)and specificity(94.59%).Conclusion SWE combined with SMI can further improve the diagnostic efficiency of benign and malignant thyroid nodules and achieve quantitative evaluation and dynamic observation of lesions,which has application and promotion value.