[Understanding and reflection on the prevention and control of pre-myopia in children].

The International Myopia Institute introduced the concept of "pre-myopia" in 2019, defining it as children with refractive error ≤+0.75 D and >-0.50 D. By considering baseline refractive error, age, and other quantifiable risk factors, there is a significant likelihood that individuals falling into this category may develop myopia in the future. Therefore, it is deemed worthwhile to implement preventative intervention measures.This article delves into the epidemiology of premyopia in children and adolescents, the criteria for determining pre-myopia, the characteristics of refractive changes, and the existing evidence gaps in pre-myopia control technology. Furthermore, it explores the role and advantages of implementing pre-myopia control to enhance efforts in preventing and managing myopia. The paper highlights the essential value and future trajectory of pre-myopia control in the comprehensive management of myopia. The ultimate goal is to foster collaboration with professionals, aiming to discuss innovative strategies for effectively preventing and managing the onset and progression of myopia.

[Epidemiology of high myopia among children and adolescents in China].

Myopia, especially high myopia, seriously affects the children and adolescents' quality of learning and life relating to a series of eye diseases. More and more studies show that the prevalence of high myopia in children and adolescents in China continues to rise, and gradually increases with age, showing a trend of younger age development. In this review, the existing literature was systematically reviewed to explore the differences in the prevalence of high myopia among people at different times, ages, and regions and understand the epidemiological status of high myopia in children and adolescents, so as to provide theoretical basis for further prevention and control of high myopia.

[Two-year follow-up study in type 2 diabetic patients with mild visual impairment].

Objective: To determine the 2-year visual prognosis in Chinese type 2 diabetic patients with mild visual impairment and identify the predictors factors. Method: This was a 2-year population-based cohort study. The study population consisted of 650 type 2 diabetic patients with bilateral mild visual impairment in 2014 who were followed up in 2016. The demographic information, systemic and ophthalmological examination results for each participant was collected. Mild visual impairment was defined as best-corrected visual acuity (BCVA)<20/25 to ≥20/63, moderate and severe visual impairment was defined as BCVA<20/63 to ≥20/400, blindness was defined as BCVA<20/400 following the International Council of Ophthalmology (ICO) 2002 definition. The two-year visual prognosis was divided into three groups: visual impairment regression, progression, and stable. Using chi-square test or independent t-test, the predictor factors of visual prognosis and the leading causes of visual impairment were studied. Results: 605 patients completed the follow-up in 2016. Among them, 477 were still bilateral mild visual impairment, accounting for 78.8% (477/605). The level of unilateral or bilateral visual impairment regressed in 8.1% (49/605), while progressed in 13.1% (79/605). Young age (t=2.7, P<0.05), short duration of diabetes (t=2.5, P<0.05), low blood glycemic hemoglobin (t=2.5, P<0.05) and total cholesterol (t=2.8, P<0.05) were associated with regression of visual impairment. Low levels of education (t=5.2, P<0.05), high blood glycemic hemoglobin (t=2.4, P<0.05) and total cholesterol (t=2.4, P<0.05)were associated with progression of visual impairment. Cataracts and diabetic retinopathy were the first and second cause of mild, moderate severe visual impairment or blindness. Conclusions: The percentage of 2-year visual acuity decline is relatively high in type 2 diabetic patients with mild visual impairment. We should strengthen blood glucose and cholesterol control to reduce the progress of visual impairment.(Chin J Ophthalmol, 2021, 57: 766-771).

Identification of miRNAs, mRNAs, lncRNAs, and circRNAs associated with hepatocellular carcinoma recurrence after interferon treatment.

To study the molecular mechanism of interferon-alpha (IFN-α) in the treatment of hepatocellular carcinoma (HCC) and the molecular markers that can predict the therapeutic effect, differentially expressed (DE)-miRNAs, -mRNAs, -lncRNAs, and -circRNAs were screened between 12 samples collected from 4 patients who had not received treatment (control), 4 patients who had received recombinant human interferon a-2b treatment (case1), and 4 patients who had relapsed after receiving recombinant human interferon a-2b treatment (case2). Enrichment analyses were performed to determine the principal functions of the DE-RNAs. We also constructed protein-protein interactions (PPI) and competing endogenous RNA (ceRNA) networks. In addition, a series-cluster analysis was performed to analyze changes in gene expression across different groups of HCC. Furthermore, the expression of the genes were verified in the Cancer Genome Atlas (TCGA) database. A total of 36 union DE-miRNAs, 175 union DE-mRNAs, 65 union DE-lncRNAs, and 52 union DE-circRNAs were obtained between the control vs case1, and case2 vs case1 groups. DE-mRNAs were mainly involved in the mitochondrial inner membrane. DE-circRNAs were mainly enriched in the Golgi apparatus. ceRNA network contained 68 DE-mRNAs, 26 DE-miRNAs, 45 DE-lncRNAs, and 23 DE-circRNAs. A total of 24 DE-miRNAs, 175 DE-mRNAs, 65 DE-lncRNAs, and 52 DE-circRNAs were classified into eight profiles, respectively. A total of 26 genes showed a significant correlation with prognosis of HCC (p < 0.05). Some genes may be used to predict the efficacy of IFN-α in the treatment of HCC. The results may lay a foundation for investigating the different sensitivities of IFN-α in the treatment of HCC.

[Orderly promoting myopia screening, refractive archives establishment, and the closed-loop management of myopia prevention and control for children and adolescents].

In China, the problem of myopia among children and adolescents is prominent, and it is urgent to strengthen the prevention and control. Myopia screening and refractive archives establishment are important basic work for myopia prevention and control. However, at present, myopia screening, refractive archives establishment as well as its management and application are still in the initial stage, and face many problems and challenges. In this paper, the significance and standardization of myopia screening and refractive archives establishment, hierarchical closed-loop management after the screening, as well as the difficulties and prospects are discussed, hoping to provide a reference for orderly promoting myopia prevention and control, reducing the prevalence of myopia among children and adolescents in China and promoting the improvement of vision health.

[Forcasting the prevalence of myopia among students aged 6-18 years in China from 2021 to 2030].

Objective: To predict the prevalence of myopia among Chinese students aged 6-18 years under different intervention scenarios from 2021 to 2030. Methods: The multi-state Markov model was developed based on the transition process of study stages and myopia statuses. The development of myopia was simplified into two statuses: non-myopia and myopia. Students aged 6-18 years were also divided according to their study stages including senior kindergarten, primary school (from Grade 1 to 6), junior school (from Grade 1 to 3) and high school (from Grade 1 to 3). The parameters were extracted from the National Myopia Investigation in 2018 and published articles of cohort studies. The transition probability was applied to simulate the intervention scenarios, and sensitivity analysis was carried out. Results: The cumulative incidence of myopia among Chinese school-aged children and adolescents would increase consistently. It would be 91.3% (min to max: 83.7% to 96.7%) upon graduation from high school. Without any intervention, the myopia prevalence would increase to 61.8% (min to max: 55.4% to 69.5%) by 2030 among Chinese school-aged children and adolescents. And the myopia prevalence among students in primary schools, junior schools and high schools would be 45.6% (min to max: 40.2% to 54.3%), 81.3% (min to max: 72.6% to 91.0%) and 90.5% (min to max: 82.4% to 96.7%), respectively, all higher than the national target. If the interventions could achieve 70% of the desired effect, the myopia prevalence would be lower than the national target at each stage. Conclusions: Without effective interventions, the prevalence of myopia among students aged 6-18 years may keep increasing in the next ten years. If the interventions achieve the desired effect, the national target for myopia prevention and control could be reached. It is urgent to identify more effective interventions and call on the whole society to participate in the myopia prevention action to achieve the national goal by 2030. (Chin J Ophthalmol, 2021, 57: 261-267).

[The safety of atropine for myopia prevention and control].

Atropine is a classical drug with a wide use in clinical practice. In ophthalmology, atropine can be used for cycloplegia before optometry, and the treatment of amblyopia, iridocyclitis, malignant glaucoma, etc. In recent years, the "old drugs with new application " research and application of atropine for myopia prevention and control has become a hotspot and the efficacy of atropine has been preliminarily recognized. However, before the widely used in clinical, the safety of atropine draws attention. Researches concerning side effects of atropine were searched. The most common problem is photophobia due to dilated pupils, followed by poor near visual acuity, allergy and inflammation, local irritation. Other side effects include withdraw rebound, dry eyes, elevation of intraocular pressure, system reactions, photic damage and toxicity. Among them, some side effects are theoretical yet, and the long-term effects of some side reactions are not clear. Further research and exploration is needed to serve clinical evidence. At present, investigational usage for myopia prevention and control in clinical trials of atropine can be beneficial. Safety observation and efficacy evaluation are equally important in the course of application. (Chin J Ophthalmol, 2021, 57: 299-304).

[Epidemiological characteristics of pneumoconiosis in Gansu Province from 2010 to 2018].

Objective: The epidemiological characteristics of occupational pneumoconiosis in Gansu Province from 2010 to 2018 were analyzed to provide a theoretical basis for the development of prevention and control strategies for pneumoconiosis in Gansu Province. Methods: In March 2019, the data of newly diagnosed occupational pneumoconiosis in 2010-2018 and the data of occupational pneumoconiosis as of December 31, 2018 in Gansu Province were collected by the Occupational Disease and Occupational Health Information Monitoring System. The stage, type of disease, time, enterprise information of newly diagnosed pneumoconiosis and the region, type of disease, enterprise information of existed pneumoconiosis were analyzed. Results: From 2010 to 2018, a total of 1269 new cases of occupational pneumoconiosis were reported in Gansu Province, including 818 cases (64.46%) of stage I pneumoconiosis, 284 cases (22.38%) of stage II pneumoconiosis, 167 cases (13.16%) of stage III pneumoconiosis. Silicosis, coal worker's pneumoconiosis and cement pneumoconiosis ranks the top 3, accounting for 55.71% (707/1269) , 37.67% (478/1269) and 3.78% (48/1269) of the total number, respectively. The new cases of stage III pneumoconiosis were mainly distributed in private economy (58.09%, 79/136) and small-sized (59.88%, 97/162) enterprises. As of December 31, 2018, Gansu Province had reported a total of 12211 cases of occupational pneumoconiosis, of which 58.16% (7102/12211) were coal worker's pneumoconiosis and 28.15% (3438/12211) were silicosis. Mainly distributed in Baiyin city (21.63%, 2641/12211) , Lanzhou city (17.79%, 2172/12211) and Wuwei city (13.73%, 1676/12211) . The existed cases of pneumoconiosis are mainly distributed in state-owned economy (76.95%, 9396/12211) and large-sized (54.23%, 6622/12211) enterprises. Conclusion: Silicosis and coal worker's pneumoconiosis are the main type of pneumoconiosis in Gansu Province. And the number of silicosis reported is on the rise, which should be taken seriously. Pneumoconiosis in Gansu Province is mainly distributed in state-owned economy and large-sized enterprises. However, pneumoconiosis patients in private economy and small-sized enterprise is generally serious, so it should be the focus of supervision.

[Detection of right-to-left shunt with transthoracic contrast echocardiography in patients with pulmonary hypertension].

Objective: To explore the value of right heart contrast echocardiography in etiological diagnosis and severity assessment of pulmonary hypertension (PH). Methods: A retrospective analysis was conducted on 74 patients who underwent transthoracic contrast echocardiography in China-Japan Friendship Hospital from May 2015 to July 2018, all of whom were diagnosed as PH by right heart catheterization. Patients were divided into three groups according to contrast echocardiography: the intra-cardiac shunt group (<4 cardiac cycles with microbubbles in the left heart); Intrapulmonary shunt group (>4 cardiac cycles with microbubbles in the left heart); non-shunt group. The etiology, partial arterial oxygen pressure (PO(2)), N-terminal pro-brain natriuretic peptide (NT-proBNP), mean pulmonary artery pressure (mPAP), right atrial pressure (RAP), pulmonary vascular resistance (PVR) and cardiac output (CO) were analyzed. Central nervous system complications were also compared among the three groups. Results: Among the 74 patients, right-to-left shunt was found in 28 cases (37.8%) by contrast echocardiography, including 11 cases (14.9%) of intra-cardiac shunt and 17 cases (23.0%) of intrapulmonary shunt. In the 11 cases of intra-cardiac shunt, 7 were diagnosed with congenital heart disease and 4 were patent foramen. Two with hereditary hemorrhagic telangiectasia (HHT) and 1 with pulmonary arteriovenous malformation (PAVM) were included in the 16 cases of intrapulmonary shunt. There was no statistical difference in PO(2), mPAP, PVR, NT-proBNP, RAP, CO and functional class among the three groups (all P>0.05). A total of 5 cases (6.8%) were found with nervous system comorbidities, 4 cases (5.4%) with cerebral infarction and 1 cases epilepsy, and 2 cases of cerebral infarction were diagnosed as paradoxical embolism. Nervous system complications were more common in patients with intra-cardiac shunt than in other groups. Conclusion: While right-to-left shunt detected by contrast echocardiography has no relationship with disease severity, it has complementary value in the etiological diagnosis of PH, and intra-cardiac shunt may increase the risk of nervous system complications.

[Epidemiological study of occupational diseases in Gansu province, China in 2010-2017].

Objective: To analyze the epidemiological characteristics of occupational diseases in Gansu Province, China in 2010-2017, and to provide a scientific basis for the prevention and control of occupational diseases. Methods: The cluster sampling method was adopted to make statistical analysis of 1339 cases of occupational disease reported by "occupational disease and occupational health information monitoring system" in Gansu province from 2010 to 2017, to investigate the diseases, regions and industries of occupational diseases in June 2018. Results: A total of 1339 cases of occupational diseases (39 types, 8 classes) were diagnosed and reposed in 2010-2017. The three most frequent diseases were pneumoconiosis (87.53%, 1172/1339), occupational poisonings (5.83%, 78/1339), and occupational ear, nose, and throat (ENT) diseases (3.14%, 42/1339). The cases of silicosis accounted for 54.61% (640/1172) of all cases of pneumoconiosis, the second was coalworker pneumoconiosis, which accounted for 38.57% (452/1172). In the cases of occupational poisonings, 32.05% (25/78) suffered from carbon monoxide poisoning. Patients with occupational diseases were reported in 14 districts of Gansu, mostly in Lanzhou (27.52%, 347/1261), Jinchang (16.57%, 209/1261), and Baiyin (14.20%, 179/1261). The reported cases are mainly concentrated in mining (71.56%, 468/654) and manufacturing (21.87%, 143/654), the types of state-owned economy (55.63%, 692/1244) and private economy (33.68%, 419/1244), large (43.41%, 540/1244) and small enterprises (35.21%, 438/1244) in 2010-2017 in Gansu. Conclusion: The pneumoconiosis caused by silicious and coal dust and the occupational poisonings caused by carbon monoxide seem to be the main occupational hazards in Gansu province. Occupational diseases occur in all districts of Guangzhou and in various industries. The state-owned economy and private sector, large and small enterprises should be the focuses of occupational health supervision.

[Strengthening the understanding of the pathological evolution of myopia].

The concern of high myopia in adolescents is increasingly prominent, because of the high prevalence and early onset of myopia in younger children. High myopia increases the risk of various fundus complications, resulting in serious damage to the vision of the working population. The mechanisms underlying the fundus pathology in high myopia remain unknown, although some studies have indicated the initial thinning of the choroid during the myopia progression might count a lot. The thinning of the choroid would influence the blood supply of the retina and sclera and accelerate the progression of myopia to high myopia, inducing the pathologic changes of the fundus. Since the treatment for pathological myopia is limited and cannot reverse the already existed visual impairment, preventive measures are necessary, including the attempts to delay the onset of myopia, to retard progression from mild myopia to high myopia and to retard the pathological changes of high myopia. Future researches should strengthen the understanding of the characteristics of pathologic changes of myopia, establish a predictive index system and a health management system to monitor early pathological changes, and promote early detection and intervention, so as to prevent fundus complications related to high myopia in multiple ways and avoid blindness and visual impairment caused by pathological fundus changes of myopia. (Chin J Ophthalmol, 2019, 55:721-725).

[Effect of monoacylglycerol lipase with proliferation of MHCC97H human liver cancer cells in vivo].

Objective: To investigate the effects of different expression of monoacylglycerol lipase (MAGL) in tumor-associated macrophages (TAMs) with the proliferation of MHCC97H human liver cancer cells in vivo and its mechanism. Methods: Human peripheral blood-derived monocyte was induced to differentiate into M2-type TAMs and was identified by flow cytometry. The co-culture model of TAMs and MHCC97H human liver cancer cells was established, and the expression of MAGL in TAMs cells was detected by qRT-PCR. The expression of MAGL in TAMs cells was detected by plasmid transfection. ELISA and qRT-PCR was used to detect the mRNA expression levels and secretion levels of inflammatory factors in TAMs cells. The subcutaneous tumor model of MHCC97H mice was constructed to observe the effect of different expression of MAGL in TAMs cells with the proliferation of MHCC97H human liver cancer cells in vivo. F-test was used for the measurement of homogeneity of variance between two independent samples. A t-test was used for homogeneity of variance, and the corrected t-test was used for non-homogeneity of variance. Results: Human peripheral blood-derived monocytes were successfully induced to differentiate into M2-type TAMs. An in vitro co-culture model was established. qRT-PCR showed that MHCC97H human liver cancer cells significantly down-regulated the expressional level of MAGL in TAMs cells. The constructed subcutaneous tumor model of mice demonstrated that up-regulation up-regulation of MAGL expression in M2-type TAMs inhibited the proliferation of MHCC97H human liver cancer cells in vivo. Furthermore, the mechanistic study illustrated that the high expression of MAGL promoted the transcription and secretion of inflammatory factors such as interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha in M2-type TAMs cells. Conclusion: The overexpression of MAGL inhibits the proliferation of MHCC97H hepatocellular carcinoma cells in vivo, and its mechanism may be associated to the release of inflammatory factors that from TAMs cells.

Long non-coding RNA PICART1 suppresses proliferation and promotes apoptosis in lung cancer cells by inhibiting JAK2/STAT3 signaling.

Lung cancer remains the most common cause of tumor-related death worldwide. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the development of various cancers, including lung cancer. This study aimed to investigate the effect and the molecular basis of lncRNA PICART1 on lung cancer. We first assessed the PICART1 expression in lung cancer in vitro and vivo by qRT-PCR. Then the expression of PICART1 in SPC-A-1 and NCI-H1975 cell lines was inhibited and overexpressed by transient transfections. Thereafter, cell viability, cell cycle, migration and apoptosis were respectively measured by MTT, Transwell and flow cytometry assay. Furthermore, qRT-PCR and western blot analysis were mainly performed to assess the expression levels of apoptosis- and migration-related proteins and JAK2/STAT3 pathway proteins. Tumor formation was measured by xenograft tumor model assay in vivo. PICART1 expression was down-regulated in human lung cancer tissues and cell lines. Knockdown of PICART1 increased cell viability of lung cancer cell lines. However, PICART1 overexpression inhibited cell cycle progression and promoted apoptosis in SPC-A-1 and NCI-H1975 cell lines. PICART1 overexpression also inhibited migration, as evidenced by up-regulation of E-cadherin, and down-regulation of Twist1, MMP2 and MMP9. Furthermore, we found PICART1 inhibition may regulate cell apoptosis and migration through activating JAK2/STAT3 pathway. In vivo experiments revealed that PICART1 knockdown significantly promoted tumor formation. This study demonstrates that PICART1 overexpression represents an anti-growth and anti-metastasis role in lung cancer cells. Additionally, PICART1 acts as a tumor suppressor may be via regulation of JAK2/STAT3 pathway.

Cancer stem cell markers in glioblastoma - an update.

The glioblastoma includes brain tumors, which are very aggressive in nature and are among the most common brain tumors in adults. Latest therapeutic avenues involve combination approach. However, the observed median survival is still no more than 15 months. Moreover, there is a scarcity of accurate pre-clinical model systems, which in turn resulted in limited treatment options for this disease. Cancer stem cells are attractive avenues in anticancer research against glioblastoma. Most of the recent studies are focused towards the identification of novel markers for cancer stem cells. The present review article is focused on two important markers in current research viz. Prominin-1 and NPM1 in glioblastoma.

Evolution of differential efficiency in blue InGaN laser diodes before and after a lasing threshold.

The optical power emitting from the cavity facet of blue InGaN-based laser diodes (LDs) is measured to investigate the efficiency droop. The efficiency droop behavior of blue InGaN-based LDs near the threshold is confirmed in our experiments. From measurements of optical power at different wavelengths, it is analyzed that the droop behavior of LDs can be ascribed to the efficiency reduction of longer wavelengths. The efficiency of longer wavelengths is subject to the carrier occupation process in quantum levels. In addition, it is found that the droop behavior may be largely affected by the relatively large threshold current of InGaN-based LDs and the screening effect of polarization, and it can be suppressed by stimulated emission.

[Construction and identification of lentiviral vector mediated GATA-3 gene RNA interference in mouse].

Objective:The aim of this study was to construct and identify a lentiviral vector for RNA interference of mouse GATA-3.Method:The coding region of the GATA-3 gene sequences were analyzed for a single-stranded oligo design and synthesis.PCR was performed for splicing reaction of synthetic oligo,which was synthesized into the lentiviral vector and transformed into the competent cell DH5α.An expression vector shRNA-GATA-3 was constructed after sequencing and identifying the gene sequence of the recombinant clones.Accoding to the target gene sequence ,four pairs are as following: siRNA-685 group(LV3-GATA-3-Mus-685),siRNA-1152 group (LV3-GATA-3-Mus-1152),siRNA-1615 group(LV3-GATA-3-Mus-1615) and control group ,which were designed and syntheized and builded into the lentiviral carrier.The shRNA vectors were cotransfected with expression vectors into the 293T cell line,and the optimal interference sequence was screened by QPCR. The 293T cells were cotranfected with the constructed lentiviral interference vectors and packing plasmids,the viruses were packed,the virus stock was collected and concentrated by ultracentrifugation,and the titer of the viruses was determined. Result:Gene sequence proved that the recombinant clone gene sequence was correct,and the lentiviral vector was successfully constructed. The relative expression of GATA-3 mRNA in siRNA-1615 group(0.004) was significantly reduced after RNA interference comparing with that in the control group(0.022),siRNA-1152 group(0.009) and siRNA-685 group(0.009). The screened LV3-GATA-3-Mus-1615 ,as the most effective interference sequence,was constructed into the lentiviral vector.The titer of the concentrated virus of LV3-GATA-3-Mus-1615 was 5×108 TU/ml in the viral supernate of 293T cells collected at 48 hours after co-transfection. Conclusion:Alentiviral RNAi expression vector targeting the GATA-3 gene (LV3-GATA-3-Mus-1615) was successfully constrcted and identified.

[The study of establishment of the " Chinese provincial Blindness prevention technical guidance group performance evaluation system"].

Objective: To establish an assessment system, including indexes and scoring methods, that can be used for performance evaluation of the provincial blindness prevention technical guidance group properly and effectively . Methods: The indexes and scoring methods were set based on the core content of The " National Plan of Prevention and Treatment of Blindness (2012-2015)" , the specific requirement and target of the World Health Organization (WHO) "For the General Eye Health: Global plan of Action (2014-2019)" , and the current situation of the China's provinces and autonomous regions. These indexes should be of effectiveness, feasibility, comparability, guidance and advancing. Formed by a literature review of candidate indicators, the framework of the system is built by qualitative assessment. With the Delphi method, the system was further revised and improved. Empirical pilot study was then used to prove the feasibility, followed by the final qualitative analysis that establish the " Chinese provincial Blindness prevention technical guidance group performance evaluation system" . Results: Through the literature review and qualitative assessment, a six dimensional system framework was built, including 6 first-level indicators, 16 second-level indicators, and 29 third-level indicators through Delphi method evaluation. With the variation coefficient method, the coeffiences of the first-level index weight were calculated as: Organization and management 0.15, Development and implementation of blindness prevention plans 0.15, Implementation of blindness prevention projects 0.14, Training 0.17, Health education 0.18, and Cooperation and exchanges 0.21. The specific scoring method for this system is confirmed as: data and files check, field interview, and record interview, sampling investigation. Empirical pilot study was conducted in the Jilin, Guizhou and Gansu provinces, and the self-assessment results from local experts were consistent with the scores from the systems. Conclusion: This system established is appropriate at current time, and it can effectively evaluate the performance of the Chinese provincial Blindness prevention technical guidance group. (Chin J Ophthalmol, 2016, 52:814-824).

[A cross-sectional study of moderate or severe visual impairment and blindness in residents with type 2 diabetes living in Xinjing Town, Shanghai].

Objective: To investigate the prevalence, underlying causes and risk factors of moderate or severe visual impairment and blindness in a population with type 2 diabetes in Xinjing Town, Shanghai, China. Methods: A cross-sectional survey among local Han adult residents, who were previously diagnosed as type 2 diabetes, was conducted between October 2014 and January 2015. The survey was preceded by a pilot study; operational methods were refined and quality assurance evaluation was carried out. The best corrected visual acuity was recorded and classified following the modified World Health Organization grading system. Assigned ophthalmic doctors assured the leading causes of every blind or visually impaired eye. Binary logistic regression analysis was used to determine the related factors of blindness and moderate or severe visual impairment. Results: A total of 2 216 type 2 diabetic residents were enrolled, and 166 eyes (3.7%, 166/4 432) were blind. Cataract was the leading cause of blindness (39.8%); macular degeneration (18.0%) and eyeball atrophy (11.4%) were the second and third leading causes of blindness, respectively. Moderate or severe visual impairment was found in 376 eyes (8.5%, 376/4 432), and the most frequent cause was cataract (65.7%), followed by diabetic retinopathy (9.8%) and macular degeneration (9.4% ). Older age, female gender, earlier onset diabetes and a lower spherical equivalent in the better eye were associated with best corrected visual acuity<20/63 in the better eye. Conclusion: The prevalences of moderate or severe visual impairment and blindness in our population with type 2 diabetes were high. (Chin J Ophthalmol, 2016, 52: 825-830).

Emission efficiency enhanced by reducing the concentration of residual carbon impurities in InGaN/GaN multiple quantum well light emitting diodes.

A series of samples with varying growth pressure are grown and their optical and structural properties are investigated. It is found that the residual carbon concentration decreases when the reactor pressure increases from 80 to 450 Torr during the InGaN/GaN multiple quantum well growth. It results in an enhanced peak intensity of electroluminescence because carbon impurities can induce deep energy levels and act as non-radiative recombination centers in InGaN layers.