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.

Objective:To explore the feasibility and conformity of cone contrast test (CCT) and pseudoisochromatic plate test applied in medical selection of pilot.Methods:One hundred and sixteen male students were selected from pilot candidates by stratified sampling method. All students were tested the pseudoisochromatic plate test and the red, green, and blue cone contrast sensitivity and were divided into normal group, color weakness group and color blindness group according to the results of the pseudoisochromatic plate test. The students with a CCT score below 75 were judged as color vision anomalopia. The coincidence rates of the 2 detection results were compared and analyzed.Results:There were 76 students in normal group, 9 students in color weakness group and 31 students in color blindness group. Students with color vision abnormalities were mainly characterized by red-green color blindness and green color weakness, manifested by a significant decrease in CCT scores of red and green ( P=0.012 or <0.001), but there was no significant difference in the blue CCT scores among 3 groups (both P>0.05). The CCT scores of normal students were not less than 75 points, which meant that the compliance rate was 100%. The proportion of students in the color blindness group below 75 points was 29/31 (with a conformity rate of 93.5%), while the proportion in the color weakness group was 2/9. Conclusions:The conclusions of CCT and pseudoisochromatic plate test for identifying color blindness and normal students are basically consistent, but the conformity rate for identifying color weakness assessment by pseudoisochromatic plate test is relatively low. It is suggested that CCT would be the complement for identifying color weakness and marginal color vision abnormalities in the medical selection for pilot.

Objective:To explore the feasibility and conformity of cone contrast test (CCT) and pseudoisochromatic plate test applied in medical selection of pilot.Methods:One hundred and sixteen male students were selected from pilot candidates by stratified sampling method. All students were tested the pseudoisochromatic plate test and the red, green, and blue cone contrast sensitivity and were divided into normal group, color weakness group and color blindness group according to the results of the pseudoisochromatic plate test. The students with a CCT score below 75 were judged as color vision anomalopia. The coincidence rates of the 2 detection results were compared and analyzed.Results:There were 76 students in normal group, 9 students in color weakness group and 31 students in color blindness group. Students with color vision abnormalities were mainly characterized by red-green color blindness and green color weakness, manifested by a significant decrease in CCT scores of red and green ( P=0.012 or <0.001), but there was no significant difference in the blue CCT scores among 3 groups (both P>0.05). The CCT scores of normal students were not less than 75 points, which meant that the compliance rate was 100%. The proportion of students in the color blindness group below 75 points was 29/31 (with a conformity rate of 93.5%), while the proportion in the color weakness group was 2/9. Conclusions:The conclusions of CCT and pseudoisochromatic plate test for identifying color blindness and normal students are basically consistent, but the conformity rate for identifying color weakness assessment by pseudoisochromatic plate test is relatively low. It is suggested that CCT would be the complement for identifying color weakness and marginal color vision abnormalities in the medical selection for pilot.

Objective:To put forward the assessment and qualification suggestions for the military flying personnel with laser corneal refractive surgery by analyzing the cases of active military flying personnel in China and reviewing the progress of refractive surgery abroad.Method:Twelve cases of laser corneal refractive surgery, including photorefractive keratectomy (PRK) and laser subepithelial keratomileusis (LASEK) of the flying personnel treated in Air Force Medical Center, PLA from January of 2012 to December of 2021, were analyzed retrospectively, and the relevant literatures were reviewed.Results:Five cases recovered to 1.0 or better distance visual acuity by 7 d, another 3 by 1 month. Till to 2 months all 12 cases recovered to that level. The visual acuity was stable 2-3 months after operation, and the refraction tended to be stable 1 month after operation. All 12 flying personnel returned to flight duty successfully 2-6 months after operation.Conclusions:It is recommended to use surface laser corneal refractive surgery (PRK and LASEK) to correct myopia for military flying personnel and the optimum re-flight time is 2-3 months after operation in case of passing the regular aviation medical evaluation.

Objective:To put forward the assessment and qualification suggestions for the military flying personnel with laser corneal refractive surgery by analyzing the cases of active military flying personnel in China and reviewing the progress of refractive surgery abroad.Method:Twelve cases of laser corneal refractive surgery, including photorefractive keratectomy (PRK) and laser subepithelial keratomileusis (LASEK) of the flying personnel treated in Air Force Medical Center, PLA from January of 2012 to December of 2021, were analyzed retrospectively, and the relevant literatures were reviewed.Results:Five cases recovered to 1.0 or better distance visual acuity by 7 d, another 3 by 1 month. Till to 2 months all 12 cases recovered to that level. The visual acuity was stable 2-3 months after operation, and the refraction tended to be stable 1 month after operation. All 12 flying personnel returned to flight duty successfully 2-6 months after operation.Conclusions:It is recommended to use surface laser corneal refractive surgery (PRK and LASEK) to correct myopia for military flying personnel and the optimum re-flight time is 2-3 months after operation in case of passing the regular aviation medical evaluation.

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 .

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.