[Epidemiological investigation and risk factors of diabetic retinopathy in Yunnan Province].

To investigate the prevalence and epidemiological characteristics of diabetic retinopathy (DR) in Yunnan Province, explore its risk factors, and provide a basis for the prevention and treatment of chronic complications of diabetes mellitus (DM). This is a large cross-sectional study, in all, 1 524 DM patients in 16 communities and villages of Yunnan Province who were registered in health service centers were included in this study from August to November 2019. All patients completed a uniform questionnaire, anthropometric measurements, biochemical measurements, and auxiliary examinations. Logistic regression analysis was used to screen the risk factors of DR. The prevalence rates of DR, mild non-proliferative DR (mild-NPDR), and referable DR (RDR) were 16.0% (244/1 524), 4.5% (69/1 524), and 11.5% (175/1 524), respectively. Glycated hemoglobin A1c (HbA1c)≥7.0% was the risk factor of mild-NPDR (OR=1.872, 95%CI 1.055-3.323) and RDR (OR=4.821, 95%CI 2.917-7.969). Blood pressure≥130/80 mmHg (1 mmHg=0.133 kPa) was the risk factor of mild-NPDR (OR=1.933, 95%CI 1.112-3.358) and RDR (OR=1.505, 95%CI 1.063-2.130). In Yunnan Province, 16.0% DM patients had accompanying DR, wherein about 71.7% of them required an ophthalmology referral, and the high incidence of RDR in DM patients was associated with poor control of blood glucose and blood pressure.

[To determine the value of iMAX, a new electrodiagnostic method, and its application in the evaluation of peripheral motor nerve excitability].

Objective: To test the new method of iMAX (the minimum stimulus current that elicits the maximum compound muscle action potential amplitude) electrodiagnosis, verify the feasibility of this method in evaluating the excitability of peripheral motor axons, and preliminarily explore the clinical application value. Methods: This study was a cross-sectional study. A total of 50 healthy subjects were recruited from the outpatient department of Peking University Third Hospital from June 2022 to March 2023, including 25 males and 25 females, aged 25-68 (48±8) years. Eleven patients with Charcot-Marie-Pain-1A (CMT1A), 7 males and 4 females, aged 19-55 (41±13) years and 21 patients with diabetic peripheral neuropathy (DPN), 10 males and 11 females, aged 28-79 (53±16) years were enrolled in this study. iMAX of bilateral median nerves, ulnar nerves and peroneal nerves were detected in all patients. Repeatable motor responses with minimum motor threshold and amplitude of at least 0.1 mV and the minimum stimulus current intensity, at which the maximum compound muscle action potential amplitude is elicited, were measured respectively [1 mA increment is called (iUP) and, 0.1 mA adjustment is called (iMAX)].Comparison of the parameters: the parameters of threshold, iUP and iMAX were compared among different age groups, genders and sides, body mass index(BMI) values and detection time , as well as between CMT1A patients, DPN patients and healthy subjects. Results: In healthy subjects, the threshold, iUP value and iMAX value were (1.8±0.7) mA, (4.4±1.2) mA, and (4.2±1.3) mA respectively; ulnar nerve (3.1±1.6) mA, (6.8±3.2) mA, (6.4±3.2) mA; peroneal nerve (3.7±2.0) mA, (7.8±2.8) mA, (7.4±2.9) mA. There were statistically significant differences in threshold, iUP value and iMAX value among different age groups (all P<0.001).With the increase of age, there was a trend of increasing threshold, iUP, and iMAX values in different nerves, and the differences are statistically significant (all P<0.001). There were no significant differences in gender, side and detection time threshold, iUP value and iMAX value (all P>0.05). The parameters of healthy subjects with high BMI value were higher than those of healthy subjects with low BMI value(all P<0.05). Compared with the healthy subjects, the parameters of 11 CMT1A patients were significantly increased (all P<0.05), and the parameters of 21 DPN patients were slightly increased (P<0.05). Conclusion: The new iMAX method reflects the excitability of motor axons and early axonal dysfunction, which is an important supplement to the traditional nerve conduction, and can be used to monitor motor axon excitability disorders.

[Geographic environment-related research advances on children's myopia: intraocular and environmental exposure factors and analytical methods].

Myopia has become a global phenomenon, transitioning into a significant public health issue of worldwide reach. The escalating prevalence of myopia may lead to an increase in the incidence of related complications, potentially resulting in irreversible vision damage for individuals. This not only causes considerable economic strain on societies but also poses a serious threat to vital sectors like national defense. This review outlines various external and internal exposure factors related to childhood myopia. It places particular focus on the analysis of the interaction between geographical environmental factors and internal exposure factors, and examines the limitations of applying traditional methods in studying the relationship between childhood myopia and geographical environmental factors. The paper also introduces two spatial regression methodologies based on frequency estimation and Bayesian estimation, summarizing their feasibility and merits when applied in the study of external exposure elements related to childhood myopia. Finally, it provides a fresh perspective on regional childhood myopia prevention strategies that are conscious of geographical environmental factors.

Clinical characteristics of 14 pediatric mycoplasma pneumoniae pneumonia associated thrombosis: a retrospective study.

OBJECTIVE: This study aimed to investigate the clinical characteristics and long-term prognosis of mycoplasma pneumoniae pneumonia (MPP)-associated thrombosis and to gain a better understanding of the diagnosis and treatment of the disease. METHODS: The medical records of 14 children with MPP-associated thrombosis between January 2016 and April 2020 were retrospectively reviewed at the Tianjin Children's Hospital. RESULTS: The ages of the patients ranged from 3 to 12 years old. Among the 14 cases, there were five cases of pulmonary embolism, two cases of cerebral infarction, one case of splenic infarction, one case of cardiac embolism, two cases of cardiac embolism with comorbid pulmonary embolism, one case of internal carotid artery and pulmonary embolism, one case of combined internal carotid artery and the cerebral infarction, and one case combined cardiac embolism and lower limb artery embolism. All cases had elevated D-dimer levels. After thrombolysis and anticoagulation therapy, three cases with cerebral embolism still suffered from neurological sequelae. In contrast, the remaining cases did not develop complications. CONCLUSION: MPP-associated thrombosis can occur in any vessel of the body. Thrombosis-associated symptoms may be complex and non-specific. Elevated D-dimer levels in a child with refractory mycoplasma pneumoniae pneumonia should raise suspicion of thrombosis. The long-term prognosis of thrombosis was favorable after the timely administration of anticoagulant therapy.

[Clinical research progress of human respiratory syncytial virus vaccine].

Human respiratory syncytial virus (HRSV) is one of the main pathogen causing severe acute lower respiratory tract infections in infants and the elderly, with high incidence rate and mortality worldwide. Vaccine is one of the important measure to prevent infection, transmission and severe disease of HRSV, but currently there is no officially approved preventive vaccine for prevention of HRSV in the world. This paper reviews and analyzes the current research and development progress of HRSV vaccine, summarizes the design routes of different types of HRSV preventive vaccines, and discusses the difficulties and challenges in vaccine research and development, in order to provide reference for the research and development of HRSV vaccine and the development of clinical trials.

[Evaluation of vestibular-evoked myogenic potential for functional integrity of the brain stem in Kennedy's disease].

Objective: To investigate whether vestibular-evoked myogenic potentials(VEMPs) can be used to assess brainstem involvement in patients with Kennedy's disease (KD). Method: This was a case-control study.Twenty consecutive patients with genetically confirmed KD and 20 age-and sex-matched healthy subjects were enrolled from November 2018 to September 2020.All subjects were tested for three types of VEMPs, including cervical VEMP (c-VEMP) recorded by the sternocleidomastoid muscle (parameter:p13, n23), masseter VEMP (m-VEMP) recorded by the masseter muscle(parameter: p11), and ocular VEMP (o-VEMP) recorded by the inferior oblique muscle (parameter n10, p15).The latency of each wave, interside peak latency and interpeak latency of c-VEMP, the corrected amplitude and amplitude asymmetry ratio were recorded. Bilateral sternocleidomastoid muscle (SCMM) electromyography (EMG) was performed. The spinal cord and bulbous muscular atrophy functional rating scale (SBMAFRS) was used for assessment. Results: The mean p13 latency of c-VEMP was (15.5±1.4)ms, which was longer than that of the control group[(13.3±0.9)ms](P<0.05); the mean n23 latency was(25.5±1.4)ms, which was also longer than that of the control group[(22.5±1.0)ms] (P<0.05); the difference of bilateral p13[(2.3±0.6)ms] was significantly higher than that of the control group(P<0.05). The abnormal rates of c-, m-, o-VEMP in KD patients were 75%(15/20), 30%(6/20) and 20%(4/20), respectively. There was a significant positive correlation between c-VEMP latency and course of disease in KD patients(left: r=0.715, 0.695, right: r= 0.708, 0.715, both P<0.05). However, c-VEMP latency was negatively correlated with SBMAFRS score (left: r=-0.701, -0.694, right: r=-0.644, -0.685, both P<0.05). Abnormal rates of SCMM EMG in KD group were as follows: 15%(3/20)of patients showed spontaneous potential in resting state and 45% (9/20) of patients exhibited simple recruitment. Conclusions: The c-VEMP latency is a sensitive tool for detecting lower brainstem involvement in patients with KD, and the degree of damage increases with prolongation of disease course. The o-and m-VEMP abnormalities indicate that some KD patients develop upper brainstem damage.

[Research progress of LI-RADS categories and imaging features in predicting the prognosis of liver tumors].

The liver imaging reporting and data system (LI-RADS) is an imaging assessment system that standardizes the diagnosis of hepatocellular carcinoma (HCC), indicating the benign and malignant tumor through categories as well as major and ancillary features. The higher the LI-RADS category ranking, the higher the corresponding HCC likelihood and malignancy risk. Therefore, early diagnosis and prediction of the prognostic risk factors of liver tumors by preoperative imaging have important clinical significance for improving the survival rate and prognosis of patients. This article reviews the research progress of LI-RADS categories and related imaging features in predicting the prognosis of liver tumors.

[Association between rare UBQLN2 variants and amyotrophic lateral sclerosis in Chinese population].

Objective: To explore the association between rare UBQLN2 variants and amyotrophic lateral sclerosis (ALS) in Chinese population, and the characteristic of phenotypes of their carriers. Methods: A total of 166 ALS patients who visited Department of Neurology of Peking University Third Hospital between January 2018 and July 2020 were recruited. The next-generation sequencing was performed to screen possible pathogenic rare variants of UBQLN2. Meanwhile, control individuals were obtained from 1000 Genome Project (2 504 samples) and an in-house whole-exome sequencing database (1 812 samples), separately. The sequence kernel association test (SKAT) and the SKAT-optimal test (SKAT-O) were used to identify the association between UBQLN2 rare variants and ALS. The clinical characteristics of rare variant carriers were analyzed. Results: A total of 33 familiar ALS and 133 sporadic ALS of Chinese ancestry were enrolled. Of the 166 ALS patients, 12.7% had bulbar-onset, 85.5% had limb-onset, and 5 cases were ALS with frontotemporal dementia (3.0%). The male-to-female ratio was 1.68∶1, with a mean age at symptom onset of (43.8±12.2) years. Three possible pathogenic rare variants of UBQLN2 were detected, including c.128A>G (p.Lys43Arg), c.142G>T (p.Val48Leu) and c.1451T>G (p.Val484Gly), and all of them were novel missense mutations. Compared with 1000 Genome Project, SKAT and SKAT-O showed a P value of 2.49×10-6 and 9.22×10-7, respectively. While compared with the in-house database, SKAT and SKAT-O revealed a P value of 1.42×10-3 and 1.10×10-3, respectively. Patients who carried rare UBQLN2 variants were with a higher rate of bulbar-onset (2/3 vs 19/163, P=0.042). Conclusion: Rare variants of UBQLN2 are associated with ALS in Chinese population, and mutation of UBQLN2 may be relevant to bulbar-onset.

[Therapeutic efficacy and mechanism of action of ginsenoside Rg1 in treating acute hepatic failure in mice].

Objective: To examine the regulatory effect of ginsenoside Rg1 (G-Rg1) on endoplasmic reticulum stress and its effect on hepatocellular apoptosis in carbon tetrachloride (CCl(4))-induced acute liver failure (ALF). Methods: Forty healthy, adult male C57/BL mice were randomly divided into normal saline control (NS) group, G-Rg1 blank control (G-Rg1) group, CCl(4) model (CCl(4)) group, and G-Rg1 preventive treatment (CCl(4)+G-Rg1) group, and an ALF mouse model was established by CCl(4) induction. Blood and liver specimens were collected from all mice upon sacrifice at 12 hours post-intraperitoneal injection. Serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST) and total bilirubin (TBil) levels were determined using commercial test kits. The mRNA expression of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) was measured using real-time PCR. The protein expression of GRP78, CHOP, caspase12, and caspase3 were measured by Western blot. Histological changes in the liver were assessed by hematoxylin-eosin staining, and the expression of GRP78 and caspase3 was detected by immunohistochemistry. Hepatocyte apoptosis was determined using terminal transferase dUTP nick end labeling. Quantitative data were analyzed using one-way ANOVA, and subsequent pairwise comparisons were performed using the LSD-t method. Results: Serum ALT, AST, and TBil levels in the CCl(4)+G-Rg1 group were significantly reduced compared with those in the CCl(4) group (ALT: 691.30 ± 108.06 U/L vs 980.66 ± 110.29 U/L, F = 365.07, P < 0.05; AST: 195.40 ± 15.41 U/L vs 319.44 ± 89.32 U/L, F = 115.64, P < 0.05; TBil: 1.09 ± 0.11 mg/dl vs 1.56 ± 0.12 mg/dl, F = 211.29, P < 0.05). The relative mRNA expression of GRP78 and CHOP was significantly lower in the CCl(4) + G-Rg1 group than in the CCl(4) group (P < 0.05). The relative protein expression of caspase3, GRP78, caspase12, and CHOP was significantly reduced to different extents in the CCl(4)+G-Rg1 group compared with those in the CCl4 group (P < 0.05). The CCl(4) + G-Rg1 group showed reduced liver tissue degeneration and necrosis compared with the CCl(4) group. Furthermore, the CCl(4)+G-Rg1 group showed significantly fewer brown granules in the liver than the CCl4 group (P < 0.05), indicating that G-Rg1 preventive treatment reduced CCl(4)-induced hepatocyte apoptosis. Conclusion: G-Rg1 prophylaxis can inhibit inflammation and reduce hepatocyte necrosis and apoptosis during CCl(4)-induced ALF. Its mechanism may involve the suppression of endoplasmic reticulum stress-related signaling molecules to alleviate hepatocyte endoplasmic reticulum stress and apoptosis. The results of this study suggest that G-Rg1 may inhibit liver inflammation and hepatocyte apoptosis through multiple targets to protect liver function.

A single CT-guided percutaneous intraosseous injection of thermosensitive simvastatin/poloxamer 407 hydrogel enhances vertebral bone formation in ovariectomized minipigs.

UNLABELLED: The ultimate goal of osteoporosis treatment is prevention of fragile fracture. Local treatment targeting specific bone may decrease the incidence of osteoporotic fractures. We developed an injectable, thermosensitive simvastatin/poloxamer 407 hydrogel; a single CT-guided percutaneous intraosseous injection augmented vertebrae in ovariectomized minipigs. INTRODUCTION: The greatest hazard associated with osteoporosis is local fragility fractures. An adjunct, local treatment might be helpful to decrease the incidence of osteoporotic fracture. Studies have found that simvastatin stimulates bone formation, but the skeletal bioavailability of orally administered is low. Directly delivering simvastatin to the specific bone that is prone to fractures may reinforce the target bone and reduce the incidence of fragility fractures. METHODS: We developed an injectable, thermosensitive simvastatin/poloxamer 407 hydrogel, conducted scanning electron microscopy, rheological, and drug release analyses to evaluate the delivery system; injected it into the lumbar vertebrae of ovariectomized minipigs via minimally invasive CT-guided percutaneous vertebral injection. Three months later, BMD, microstructures, mineral apposition rates, and strength were determined by DXA, micro-CT, histology, and biomechanical test; expression of VEGF, BMP2, and osteocalcin were analyzed by immunohistochemistry and Western blots. RESULTS: Poloxamer 407 is an effective controlled delivery system for intraosseous-injected simvastatin. A single injection of the simvastatin/poloxamer 407 hydrogel significantly increased BMD, bone microstructure, and strength; the bone volume fraction and trabecular thickness increased nearly 150 %, bone strength almost doubled compared with controls (all P < 0.01); and induced higher expression of VEGF, BMP2, and osteocalcin. CONCLUSIONS: CT-guided percutaneous vertebral injection of a single simvastatin/poloxamer 407 thermosensitive hydrogel promotes bone formation in ovariectomized minipigs. The underlying mechanism appears to involve the higher expression of VEGF and BMP-2.

[Assessment of upper motor neuron dysfunction by triple stimulation technique in patients with Charcot-Marie-Tooth disease].

OBJECTIVE: To investigate the presence of upper motor neuron dysfunction in patients with Charcot-Marie-Tooth disease (CMT) by triple stimulation technique (TST) to provide evidence for gene diagnosis. METHODS: A total of 65 CMT patients confirmed by genetic testing from Peking University Third Hospital between August 2013 and August 2015, underwent physical examination and routine electrophysiological tests and triple stimulation technique. The TST combined transcranial magnetic stimulation (TMS) of the motor cortex with peripheral collision studies. The results were expressed by the TST amplitude ratio (TST test/ TST control). Based on the result of physical examination and the ratio of TST, the function of upper motor neuron was assessed. RESULTS: All of the CMT patients had typical presentations and were confirmed genetically. Hyperreflexia, Babinski sign and muscular hypertonia were discovered in lower limbs in 7 CMT patients, while 2 patients complicated with hyperreflexia and Hoffmann sign in upper limbs. TST amplitude ratio was significantly altered in 10 patients, including 5 patients with pyramid sign: hyperreflexia, Babinski sign and muscular hypertonia was discovered in lower limbs while 2 patients complicated with hyperreflexia and Hoffmann sign in upper limbs. The disease-causing mutations were: MFN2 mutations in 5 patients, 1 patient with BSCL2 mutation, 3 patients with GJB1 mutations and 1 patient with GDAP mutation. In summary, 18.5% (12 patients) of the 65 CMT patients had upper motor neuron dysfunction based on the result of physical examination and the ratio of TST. CONCLUSION: Upper motor neuron dysfunction may be found in CMT patients, which may provide clues for the testing of disease-causing mutations.

Mutations of transglutaminase-1 in Chinese patients with autosomal recessive congenital ichthyosis: a case report with clinical and genetic analysis of Chinese cases reported in literature.

BACKGROUND: Autosomal recessive congenital ichthyosis (ARCI) is a heterogeneous group of diseases of keratinization, characterized primarily by abnormal skin scaling over the whole body surface. Recently, ARCI has been designated to include the major forms of lamellar ichthyosis (LI), congenital ichthyosiform erythroderma (CIE) and harlequin ichthyosis. The first two conditions are the most common major clinical subtypes, and both are caused principally by mutations in the transglutaminase 1 gene, TGM1, although other genes may be responsible in some cases. AIM: To identify the genetic mutations underlying LI in a Chinese family with LI, and to review all the known TGM1 mutations in Chinese patients with ARCI. METHODS: The proband had the severe classic LI phenotype, and was a member of a four-generation family with close blood relationships. We sequenced the DNA of the patients and close relatives. We also reviewed 13 Chinese patients with ARCI from 8 reported families, comprising 10 patients with LI, 2 with CIE and 1 with bathing suit ichthyosis. RESULTS: We characterized 14 different TGM1 mutations. Six of these were reported in other ethnic groups initially and later in Chinese patients, while the remaining eight were first described in Chinese patients. Of the latter, five have been reported only in Chinese patients, while the remaining three have also been reported in other ethnic groups. CONCLUSION: This study expands the current spectrum on TGM1 mutation and increases the knowledge of TGM1 mutation characteristics.

[Analysis on influencing factors on loneliness in the elderly aged 60 and above in China].

Objective: To analyze the influential factors of loneliness in the elderly aged ≥60 years in China. Methods: Data used in this study were obtained from participants aged ≥60 years from the China Longitudinal Aging Social Survey, with a sample size of 7 593. Loneliness was measured with loneliness scale, and the influence of subjective and objective factors on loneliness and their interaction were analyzed with stepwise linear regression model and simple slope test. SPSS 25.0 was used for statistical analysis. PROCESS 3.3 macro program was used for simple slope test. Results: A total of 8 926 participants were included. Among the objective factors, the elderly with poor family network have a higher level of loneliness (P<0.05), and community provision of elderly care services could reduce the loneliness of the elderly (P<0.05). Elderly people with subjective aging age ≤60 years old and poor social adaptation and emotional perception have higher levels of loneliness (all P<0.05). Subjective aging age plays a negative regulatory role in the impact of community elderly care services on loneliness (P<0.05), Social adaptation and emotional perception play a negative regulatory role in the impact of family network on loneliness (P<0.05). Conclusions: Elderly people aged ≥60 years of feeling of loneliness was affected by both subjective and objective factors and subjective factors play an important regulatory role in the influence of objective factors on elderly people's feeling of loneliness in China. Therefore, while creating a good aging environment to provide strong external support for the elderly, the subjective initiative of the elderly should also be fully mobilized, to alleviate the loneliness of the elderly from these two aspects.

Evidence from Mendelian randomization: increased risk of miscarriage in patients with asthma.

OBJECTIVE: Several observational studies have revealed a possible association between asthma and miscarriage. However, inferring causal relationships from observational studies may be fraught with problems like bias, reverse causation, and residual confounding. Therefore, to assess the possible causal effect of asthma on miscarriage, we performed a two-sample Mendelian randomization (MR) analysis. MATERIALS AND METHODS: Asthma (56,167 cases and 352,255 controls) and miscarriage (9,113 cases and 89,340 controls) data from two GWAS of European ancestry were evaluated. Single nucleotide polymorphisms (SNPs) were used as instrumental variables (IVs). The random effect inverse-variance weighted (IVW) Mendelian randomization approach was used as the primary method, and MR-Egger, weighted-median, and MR-PRESSO approaches were replenished as sensitivity analysis to test the robustness of the results. RESULTS: In total, 70 SNPs were obtained using the SNP criteria. Additionally, the MR study found substantial evidence of the causality between asthma and miscarriage [IVW, OR=1.092; 95% CI=1.017-1.174; p<0.05]. The sensitivity analysis demonstrated the reliability of the MR findings [horizontal pleiotropy (MR-Egger, intercept=-0.0002; Standard error of mean, se=0.006; p=0.975)]. CONCLUSIONS: Asthma is a causal risk factor for miscarriage in European populations, according to MR evidence. Our results emphasize the significance of asthma management in reducing the risk of miscarriage in individuals with asthma.

Abrupt change reflected by the van Hove singularity in the optical spectra of CaMn2P2.

The trigonal CaAl2Si2-type structure CaMn2P2has been reported undergoing an exotic first order phase transition at the critical temperatureTN=69.5K. In this paper, we present the optical spectra for theab-plane of CaMn2P2single crystal from 300 K to 10 K for the first time. In the real part of the optical conductivity spectraσ1(ω), a direct gap could be determined at all temperatures without any Drude term visible, i.e., the sample goes through the first order phase transition from one insulator state to the other insulator state. At higher energy, an asymmetric sharp interband transition peak appears in allσ1(ω) spectra, which indicates a divergence of the joint density of states. This sharp peak could be well described by the two dimensional van Hove singularity function. In particular, this peak is very sensitive to the first order phase transition, especially the peak positionEtwhose the most prominent blue shift occurs only when the first order transition happens. Our data and analysis reveal that the first order phase transition leads to a weak partial re-normalization of the band structure. Our study will be useful in further investigations about the mechanism of the first order phase transition in the insulator.

[Research progress on the effectiveness of smallpox vaccination against mpox virus infection].

With the expansion of mpox virus infection from endemic to a global epidemic in 2022, the WHO declared that the mpox event constituted a Public Health Emergency of International Concern. Due to the high degree of gene sequence similarity among orthopox viruses and cross-reactive antibodies induced by orthoviruses, smallpox vaccination may affect the immune response induced by mpox virus infection. The analysis of the protective effects of smallpox vaccination against mpox virus infection will help define the focus of prevention and control. In this review, we clarify the protection of the smallpox vaccine against mpox virus infection by analyzing the correlation between smallpox vaccination, immune response status, and clinical data and providing evidence for the prevention, control, and strategies of mpox epidemics.

Changes in macular vascular density and retinal thickness in young myopic adults without pathological changes: an OCTA study.

OBJECTIVE: The aim of the study was to quantify the macular vascular density and retinal thickness in the eyes of young myopic people with myopia without pathological changes using optical coherence tomography angiography (OCTA). PATIENTS AND METHODS: In this cross-sectional study, 160 eyes of 80 myopia subjects without pathological changes were classified into three groups: mild myopia (N=40 eyes), moderate myopia (N=66 eyes), and high myopia (N=54 eyes). Macular vascular density (VD), retinal thickness, area of the foveal avascular zone, the flow area of the outer retina and choriocapillaris (CC) were measured using OCTA. The effects of other confounding factors including axial length, the spherical equivalent, and some systemic factors (blood pressure, height, weight, etc.) were also considered. RESULTS: As the severity of myopia increases, the CC flow area decreased (p=0.029). The superficial VD in the temporal, superior, nasal, and inferior regions was significantly lower in high myopia group compared to moderate and low myopia groups (all p<0.001). With increasing myopia, a significant reduction of deep VD was found in the superior region of the macula (p=0.007). In the fovea, there was no difference in the superficial or deep VD across groups (p=0.268 and p=0.413, respectively). Parafoveal retinal thickness was thinnest in the high myopia group and thickest in the mild myopia group (all p<0.05). The fovea was thickest in the high myopia group and thinnest in the mild myopia group (p=0.030). CONCLUSIONS: In young myopic people without pathological changes, superficial VD and retinal thickness decreased with myopia progression, except in the fovea. The CC flow area decreased with increasing myopia.