The English national risk-reduction programme for preservation of sight in diabetes

This paper discusses the new national guidelines for a systematic screening programme to detect sight-threatening diabetic retinopathy in the population of people with diabetes in England. A review of the literature examines the evidence base to support screening interventions and effective management and treatments in diabetic retinopathy. The current evidence supports the establishment of a digital retinal photography system using pupil dilation. A Policy Advisory Group has been formulated by the National Screening Committee to guide the meeting of this target in England. A conclusion is made that with increased effort and organisation, health care professionals can ensure that the screening programme is successfully implemented and rates of visual impairment and blindness caused by diabetic retinopathy can be reduced significantly.     

SDOCT imaging to identify macular pathology in patients diagnosed with diabetic maculopathy by a digital photographic retinal screening programme

Introduction

Diabetic macular edema (DME) is an important cause of vision loss. England has a national systematic photographic retinal screening programme to identify patients with diabetic eye disease. Grading retinal photographs according to this national protocol identifies surrogate markers for DME. We audited a care pathway using a spectral-domain optical coherence tomography (SDOCT) clinic to identify macular pathology in this subset of patients.

Methods

A prospective audit was performed of patients referred from screening with mild to moderate non-proliferative diabetic retinopathy (R1) and surrogate markers for diabetic macular edema (M1) attending an SDOCT clinic. The SDOCT images were graded by an ophthalmologist as SDOCT positive, borderline or negative. SDOCT positive patients were referred to the medical retina clinic. SDOCT negative and borderline patients were further reviewed in the SDOCT clinic in 6 months.

Results

From a registered screening population of 17 551 patients with diabetes mellitus, 311 patients met the inclusion criteria between (March 2008 and September 2009). We analyzed images from 311 patients’ SDOCT clinic episodes. There were 131 SDOCT negative and 12 borderline patients booked for revisit in the OCT clinic. Twenty-four were referred back to photographic screening for a variety of reasons. A total of 144 were referred to ophthalmology with OCT evidence of definite macular pathology requiring review by an ophthalmologist.

Discussion

This analysis shows that patients with diabetes, mild to moderate non-proliferative diabetic retinopathy (R1) and evidence of diabetic maculopathy on non-stereoscopic retinal photographs (M1) have a 42.1% chance of having no macular edema on SDOCT imaging as defined by standard OCT definitions of DME when graded by a retinal specialist. SDOCT imaging is a useful adjunct to colour fundus photography in screening for referable diabetic maculopathy in our screening population.     

Adding retinal photography to screening for diabetic retinopathy: a prospective study in primary care.

OBJECTIVE--To evaluate whether adding retinal photography improved community screening for diabetic retinopathy. SETTING--Mobile screening unit at rural and urban general practices in south west England. SUBJECTS--1010 diabetic patients from primary care. DESIGN--Prospective study; patients were examined by ophthalmoscopy by general practitioners or opticians without fundal photographs and again with photographs, and assessments were compared to those of an ophthalmologist. MAIN OUTCOME MEASURES--Whether fundal photography improved the sensitivity of detection of retinopathy and referrable diabetic retinopathy, and whether this sensitivity could be improved by including a review of the films by the specialist. RESULTS--Diabetic retinopathy was detected by the ophthalmologist in 205 patients (20.5%) and referrable retinopathy in 49 (4.9%). The sensitivity of the general practitioners and opticians for referrable retinopathy with ophthalmoscopy was 65%, and improved to 84% with retinal photographs. General practitioners'' sensitivity in detecting background retinopathy improved with photographs from 22% to 65%; opticians'' sensitivity in detecting background retinopathy improved from 43% to 71%. The sensitivity of detecting referrable retinopathy by general practitioners improved from 56% to 80% with photographs; for opticians it improved from 75% to 88%. CONCLUSIONS--Combining modalities of screening by providing photography with specialist review of all films in addition to direct ophthalmoscopy through dilated pupils improves assessment and referral for diabetic retinopathy by general practitioners and opticians. With further training and experience, primary care screeners should be able to achieve a sensitivity that will achieve an effective, acceptable, and economical community based screening programme for this condition.     

Prevention of blindness by screening for diabetic retinopathy: a quantitative assessment.

Diabetic retinopathy is an important cause of blindness in the Western World. A review of the randomised trials of laser photocoagulation of the retina as a method of preventing blindness from this disorder showed that this treatment is very effective, reducing the risk of blindness by 61% in a treated eye. As only one eye is needed for sight the reduction in blindness in a population will be greater than 61% because the effect of treatment in one eye is not always identical with the effect in the other eye. For analysis this reduction was taken as 73%, representing the average of the minimum and maximum estimates (61% and 85%). The effectiveness of this treatment suggests that there is the potential for a national screening programme to bring about a major reduction in blindness from this cause. A quantitative assessment of the effect of screening indicated that a programme in which patients with diabetes mellitus are systematically referred to ophthalmic opticians for a retinal examination could detect 88% of all diabetics with serious retinopathy and that 87% of these cases would be treatable. Screening and early treatment of retinopathy would prevent deterioration of visual acuity and could reduce the risk of blindness due to diabetic retinopathy by an estimated 56% (0.73 X 0.88 X 0.87). The findings suggest that an effectively managed community based screening programme encompassing detection, referral, treatment, and follow up would prevent about 260 new cases of blindness in diabetics under the age of 70 each year in England and Wales. This would represent over 10% of all cases of blindness in adults in this age group.     

Use of mobile screening unit for diabetic retinopathy in rural and urban areas.

OBJECTIVES--To compare the effectiveness of a mobile screening unit with a non-mydriatic polaroid camera in detecting diabetic retinopathy in rural and urban areas. To estimate the cost of the service. DESIGN--Prospective data collection over two years of screening for diabetic retinopathy throughout Tayside. SETTING--Tayside region, population 390,000, area 7770 km2. SUBJECTS--961 patients in rural areas and 1225 in urban areas who presented for screening. MAIN OUTCOME MEASURES--Presence of diabetic retinopathy, need for laser photocoagulation, age, duration of diabetes, and diabetic treatment. RESULTS--Compared with diabetic patients in urban areas, those in rural areas were less likely to attend a hospital based diabetic clinic (46% (442) v 86% (1054), p < 0.001); less likely to be receiving insulin (260 (27%) v 416 (34%), p < 0.001 and also after correction for differences in age distribution); more likely to have advanced (maculopathy or proliferative retinopathy) diabetic retinopathy (13% (122) v 7% (89), p < 0.001); and more likely to require urgent laser photocoagulation for previously unrecognised retinopathy (1.4% (13) v 0.5% (6), p < 0.02). The screening programme cost 10 pounds per patient screened and 1000 pounds per patient requiring laser treatment. CONCLUSION--The mobile diabetic eye screening programme detected a greater prevalence of advanced retinopathy in diabetic patients living in rural areas. Patients in rural areas were also more likely to need urgent laser photocoagulation. Present screening procedures seem to be less effective in rural areas and rural patients may benefit more from mobile screening units than urban patients.     

Cost effectiveness analysis of screening for sight threatening diabetic eye disease

ObjectiveTo measure the cost effectiveness of systematic photographic screening for sight threatening diabetic eye disease compared with existing practice.DesignCost effectiveness analysisSettingLiverpool.SubjectsA target population of 5000 diabetic patients invited for screening.ResultsBaseline prevalence of sight threatening eye disease was 14.1%. The cost effectiveness of the systematic programme was £209 (sensitivity 89%, specificity 86%, compliance 80%, annual cost £104 996) and of the opportunistic programme was £289 (combined sensitivity 63%, specificity 92%, compliance 78%, annual cost £99 981). The incremental cost effectiveness of completely replacing the opportunistic programme was £32. Absolute values of cost effectiveness were highly sensitive to varying prevalence, sensitivity and specificity, compliance, and programme size.ConclusionReplacing existing programmes with systematic screening for diabetic eye disease is justified.     

AMPK in microvascular complications of diabetes and the beneficial effects of AMPK activators from plants

BackgroundDiabetes mellitus is a multifactorial disorder with the risk of micro- and macro-vascular complications. High glucose-induced derangements in metabolic pathways are primarily associated with the initiation and progression of secondary complications namely, diabetic nephropathy, neuropathy, and retinopathy. Adenosine monophosphate-activated protein kinase (AMPK) has emerged as an attractive therapeutic target to treat various metabolic disorders including diabetes mellitus. It is a master metabolic regulator that helps in maintaining cellular energy homeostasis by promoting ATP-generating catabolic pathways and inhibiting ATP-consuming anabolic pathways. Numerous pharmacological and plant-derived bioactive compounds that increase AMP-activated protein kinase activation has shown beneficial effects by mitigating secondary complications namely retinopathy, nephropathy, and neuropathy.PurposeThe purpose of this review is to highlight current knowledge on the role of AMPK and its activators from plant origin in diabetic microvascular complications.MethodsSearch engines such as Google Scholar, PubMed, Science Direct and Web of Science are used to extract papers using relevant key words. Papers mainly focusing on the role of AMPK and AMPK activators from plant origin in diabetic nephropathy, retinopathy, and neuropathy was chosen to be highlighted.ResultsAccording to results, decrease in AMPK activation during diabetes play a causative role in the pathogenesis of diabetic microvascular complications. Some of the plant-derived bioactive compounds were beneficial in restoring AMPK activity and ameliorating diabetic microvascular complications.ConclusionAMPK activators from plant origin are beneficial in mitigating diabetic microvascular complications. These pieces of evidence will be helpful in the development of AMPK-centric therapies to mitigate diabetic microvascular complications.     

Lack of relationship between Alu repetitive elements in angiotensin converting enzyme and the severity of diabetic retinopathy

BackgroundAngiotensin-converting enzyme (ACE) stimulates angiogenesis that leads to the development of diabetic retinopathy (DR). Alu repetitive elements in ACE gene increase the expression of this enzyme. We investigated the frequency of Alu repetitive elements, insertion/deletion (I/D) polymorphism, in angiotensin-converting enzyme among diabetic retinopathy patients and whether this polymorphism is associated with the severity of retinopathy in Jordanians with type 2 diabetes.MethodsA total of 277 subjects participated in this case/ control study (100 diabetic patients without DR, 82 diabetic patients with DR, and 95 healthy control). Blood samples were withdrawn, followed by DNA extraction. Alu repetitive elements were examined by polymerase chain reaction followed by gel electrophoresis.ResultsThe genotype and allele frequencies among diabetic patients, were close to healthy controls (genotypes, II 44.4 vs. 44.7%, ID 44.4 vs. 42.6%, DD 12.2 vs. 12.8%, P = 0.402 and 0.677 respectively, alleles, I 65.6 vs. 66%, D 34.4 vs. 34%, P=0.863). Complicated diabetics with retinopathy showed similar genotype and allele frequency to those without complications. The severity of diabetic retinopathy in affected individuals was not correlated with I/D polymorphism (P=0.862).ConclusionsWe conclude that the presence of Alu repetitive elements did not increase the development or progression risk to retinopathy in Jordanian type 2 diabetic patients. No association between I or D alleles with the severity of DR was detected.     

At last the organ grinder...

Abstract

A prominent and early feature of the retinopathy of diabetes mellitus is a diffuse increase in vascular permeability. As the disease develops, the development of frank macular oedema may result in vision loss. That reactive oxygen species production is likely to be elevated in the retina, and that certain regions of the retina are enriched in substrates for lipid peroxidation, may create an environment susceptible to oxidative damage. This may be more so in the diabetic retina, where hyperglycaemia may lead to elevated oxidant production by a number of mechanisms, including the production of oxidants by vascular endothelium and leukocytes. There is substantial evidence from animal and clinical studies for both impaired antioxidant defences and increased oxidative damage in the retinae of diabetic subjects that have been, in the case of animal studies, reversible with antioxidant supplementation. Whether oxidative damage has a causative role in the pathology of diabetic retinopathy, and thus whether antioxidants can prevent or correct any retinal damage, has not been established, nor has the specific nature of any damaging species been characterised.     

Peripapillary Retinal Nerve Fiber Layer Changes in Preclinical Diabetic Retinopathy: A Meta-Analysis

BackgroundDiabetic retinopathy is a microvascular neurodegenerative disorder in diabetic patients. Peripapillary retinal nerve fiber layer changes have been described in patients with preclinical diabetic retinopathy, but study results have been inconsistent.ObjectiveTo assess changes in peripapillary retinal nerve fiber layer thickness in diabetic patients with preclinical diabetic retinopathy.MethodsA literature search was conducted through PubMed, EMBASE, Web of Science and Cochrane Library. Case-control studies on RNFL thickness in preclinical diabetic retinopathy patients and healthy controls were retrieved. A meta-analysis of weighted mean difference and a sensitivity analysis were performed using RevMan 5.2 software.ResultsThirteen case-control studies containing 668 diabetic patients and 556 healthy controls were selected. Peripapillary RNFL thickness was significantly reduced in patients with preclinical diabetic retinopathy compared to healthy controls in studies applying Optical Coherence Tomography (-2.88μm, 95%CI: -4.44 to -1.32, P = 0.0003) and in studies applying Scanning Laser Polarimeter (-4.21μm, 95%CI: -6.45 to -1.97, P = 0.0002). Reduction of RNFL thickness was significant in the superior quadrant (-3.79μm, 95%CI: -7.08 to -0.50, P = 0.02), the inferior quadrant (-2.99μm, 95%CI: -5.44 to -0.54, P = 0.02) and the nasal quadrant (-2.88μm, 95%CI: -4.93 to -0.82, P = 0.006), but was not significant in the temporal quadrant (-1.22μm, 95%CI: -3.21 to 0.76, P = 0.23), in diabetic patients.ConclusionPeripapillary RNFL thickness was significantly decreased in preclinical diabetic retinopathy patients compared to healthy control. Neurodegenerative changes due to preclinical diabetic retinopathy need more attention.     

Plasma angiogenesis and oxidative stress markers in patients with diabetic retinopathy

Abstract

Background: Neovascularization in the retina and hyperglycaemia-induced oxidative stress are implicated in the pathogenesis of diabetic retinopathy (DR). In this study, we hypothesized that the plasma angiogenic and oxidative stress markers associated with these derangements could aid in the screening of diabetic patients who are at an increased risk of developing retinopathy.

Methods: This study included normal (n?=?148), type2 diabetes without retinopathy (DNR; n?=?148), proliferative DR (PDR; n?=?74) and non-PDR (NPDR; n?=?148) subjects. Plasma concentrations of vascular endothelial growth factor-A (VEGF-A), hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase-9 (MMP-9), pigment epithelium-derived factor (PEDF), nitric oxide (NO), soluble receptors for advanced glycation end products (sRAGE), malondialdehyde (MDA) and protein thiols were estimated.

Results: A statistically significant increase was observed in the plasma concentrations of pro-angiogenic factors and markers of oxidative stress in both retinopathy groups. By contrast, the concentrations of anti-angiogenic factors and antioxidants were decreased significantly in these groups. Receiver operating characteristic analysis indicated that the plasma thresholds of HIF-1α and PEDF can be suitable markers in case of NPDR. However, in PDR, HIF-1α, NO, MMP-9 and PEDF showed high sensitivity and specificity.

Conclusions: The factors associated with hypoxia, matrix degradation and angiogenic inhibition play a crucial role in predicting DR.     

A Multi-Branch Convolutional Neural Network for Screening and Staging of Diabetic Retinopathy Based on Wide-Field Optical Coherence Tomography Angiography

BackgroundDiabetic retinopathy (DR) is one of the major causes of blindness in adults suffering from diabetes. With the development of wide-field optical coherence tomography angiography (WF-OCTA), it is to become a gold standard for diagnosing DR. The demand for automated DR diagnosis system based on OCTA images have been fostered due to large diabetic population and pervasiveness of retinopathy cases.Materials and methodsIn this study, 288 diabetic patients and 97 healthy people were imaged by the swept-source optical coherence tomography (SS-OCT) with 12 mm × 12 mm single scan centered on the fovea. A multi-branch convolutional neural network (CNN) was proposed to classify WF-OCTA images into four grades: no DR, mild non-proliferative diabetic retinopathy (NPDR), moderate to severe NPDR, and proliferative diabetic retinopathy (PDR).ResultsThe proposed model achieved a classification accuracy of 96.11%, sensitivity of 98.08% and specificity of 89.43% in detecting DR. The accuracy of the model for DR staging is 90.56%, which is higher than that of other mainstream convolution neural network models.ConclusionThis technology enables early diagnosis and objective tracking of disease progression, which may be useful for optimal treatment to reduce vision loss.     

Family Practices' Achievement of Diabetes Quality of Care Targets and Risk of Screen-Detected Diabetic Retinopathy

Background

We aimed to determine whether family practices'' achievement of diabetes quality of care targets is associated with diabetic retinal disease in registered patients.

Methods

Data for achievement of diabetes quality of care targets, including the proportion of patients with HbA1c≤7.5%, for 144 family practices in London UK, for the years 2004/5 to 2007/8, were linked to data from a population-based diabetes eye screening programme collected from September 2007 to February 2009. Analyses were adjusted for age, sex, duration and type of diabetes, unadjusted diabetes prevalence, ethnicity and deprivation category.

Results

Data were analysed for 24,458 participants with one or more eye screening results in the period. There were 9,332 (38%) with any diabetic retinopathy and 2,819 (11.5%) with sight threatening diabetic retinopathy (STDR), including 2,654 (10.9%) with maculopathy. Among participants registered at 13 family practices that were in the highest quartile for achievement of the HbA1c quality of care target for all four years of study, the relative odds of any diabetic retinopathy were 0.78 (0.69 to 0.88) P<0.001. For participants at 12 practices consistently in the lowest quartile of HbA1c achievement, the relative odds of any diabetic retinopathy were 1.16 (1.03 to 1.30), P = 0.015. In the highest achieving practices, the relative odds of maculopathy were 0.74 (0.62 to 0.89), P = 0.001 and STDR 0.77 (0.65 to 0.92), P = 0.004.

Conclusions

The risk of diabetic retinopathy might be lower at family practices that consistently achieve highly on diabetes quality of care targets for HbA1c.     

Outcomes of screening to prevent cancer: analysis of cumulative incidence of cervical abnormality and modelling of cases and deaths prevented

ObjectiveTo determine the frequency of different outcomes in women participating in cervical screening.DesignAnalysis of screening records from 348 419 women, and modelling of cases of cervical cancer and deaths with and without screening.SettingCervical screening programme in Bristol.ResultsFor every 10 000 women screened from 1976 to 1996, 1564 had abnormal cytology, 818 were investigated, and 543 had abnormal histology. One hundred and seventy six had persistent abnormality for two years or more. In the absence of screening 80 women would be expected to develop cancer of the cervix by 2011, of whom 25 would die. With screening 10 of these deaths would be avoided. Comparison of cumulative abnormality rates with numbers expected to develop cancer in the absence of screening suggests that at least 80% of high grade dyskaryosis and of high grade dysplasia would not progress to cancer. The lifetime risk of having abnormal cytology detected could be as high as 40% for women born since 1960.ConclusionsScreening is labour and resource intensive. It involves treatment for many women not destined to develop invasive cancer. The increased intervention rate for cervical abnormality in England is due to change in practice, not a cohort effect, and is probably the reason for the marked fall in incidence and mortality during the 1990s. For other cancers there is scope for major iatrogenic harm from screening because of invasive tests and treatments.

What is already known on this topic

Since the mid-1980s incidence of and mortality from cervical cancer in women born since the 1930s in England and Wales has fallen; screening is the most likely explanationFor each death prevented many women have to be screened and many are treated who would not have developed a problem

What this study adds

In the NHS cervical screening programme around 1000 women need to be screened for 35 years to prevent one deathOver 80% of women with high grade cervical intraepithelial neoplasia will not develop invasive cancer, but all need to be treatedFor each death prevented, over 150 women have an abnormal result, over 80 are referred for investigation, and over 50 have treatmentBefore the 1988 relaunch of screening with strict quality standards, for each death prevented there were 57 000 tests and 1955 women had abnormal results     

Automatic non-proliferative diabetic retinopathy screening system based on color fundus image

Background

Non-proliferative diabetic retinopathy is the early stage of diabetic retinopathy. Automatic detection of non-proliferative diabetic retinopathy is significant for clinical diagnosis, early screening and course progression of patients.

Methods

This paper introduces the design and implementation of an automatic system for screening non-proliferative diabetic retinopathy based on color fundus images. Firstly, the fundus structures, including blood vessels, optic disc and macula, are extracted and located, respectively. In particular, a new optic disc localization method using parabolic fitting is proposed based on the physiological structure characteristics of optic disc and blood vessels. Then, early lesions, such as microaneurysms, hemorrhages and hard exudates, are detected based on their respective characteristics. An equivalent optical model simulating human eyes is designed based on the anatomical structure of retina. Main structures and early lesions are reconstructed in the 3D space for better visualization. Finally, the severity of each image is evaluated based on the international criteria of diabetic retinopathy.

Results

The system has been tested on public databases and images from hospitals. Experimental results demonstrate that the proposed system achieves high accuracy for main structures and early lesions detection. The results of severity classification for non-proliferative diabetic retinopathy are also accurate and suitable.

Conclusions

Our system can assist ophthalmologists for clinical diagnosis, automatic screening and course progression of patients.

     

Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 improves diabetic retinopathy

Diabetes induced a serious of complications including diabetic retinopathy. Our study aimed to investigate the role of Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 in diabetic retinopathy. A mice model of diabetic retinopathy was established, and expression of SDF-1 and CXCR4 in retina was examined by Real-time quantitative PCR (qRT-PCR). Cells of human retinal pigment epithelial cell line ARPE-19 were treated with CXCR4 siRNAs and expression vector, and cell viability was detected by MTT assay. We found that expression of SDF-1 and CXCR4 in retina was significantly downregulated in mice with diabetic retinopathy than in normal healthy mice. High glucose treatment downregulated the expression of SDF-1 and CXCR4 in ARPE-19 cells at both mRNA and protein levels. Transfection with CXCR4 siRNAs decreased, while transfection with CXCR4 expression vector increased cell viability under high glucose treatment. We concluded that SDF-1/CXCR4 pathway improved diabetic retinopathy possibly by increasing cell viability.

Abbreviations: SDF-1: Stromal cell-derived factor 1; CXCL12: C-X-C motif chemokine 12; qRT-PCR: Real-time quantitative PCR     

Vitamin D insufficiency in diabetic retinopathy

ObjectiveTo assess the relationship between vitamin D status and diabetic retinopathy.MethodsA clinic-based, cross-sectional study was conducted at Emory University, Atlanta, Georgia. Overall, 221 patients were classified into 5 groups based on diabetes status and retinopathy findings: no diabetes or ocular disease (n = 47), no diabetes with ocular disease (n = 51), diabetes with no background diabetic retinopathy (n = 41), nonproliferative diabetic retinopathy (n = 40), and proliferative diabetic retinopathy (PDR) (n = 42). Patients with type 1 diabetes and those taking > 1,000 IU of vitamin D daily were excluded from the analyses. Study subjects underwent dilated funduscopic examination and were tested for hemoglobin A_1c, serum creatinine, and 25-hydroxyvitamin D [25(OH)D] levels between December 2009 and March 2010.ResultsAmong the study groups, there was no statistically significant difference in age, race, sex, or multivitamin use. Patients with diabetes had lower 25(OH)D levels than did those without diabetes (22.9 ng/mL versus 30.3 ng/mL, respectively; P < .001). The mean 25(OH)D levels, stratified by group, were as follows: no diabetes or ocular disease = 31.9 ng/mL; no diabetes with ocular disease = 28.8 ng/mL; no background diabetic retinopathy = 24.3 ng/ mL; nonproliferative diabetic retinopathy = 23.6 ng/mL; and PDR = 21.1 ng/mL. Univariate analysis of the 25(OH) D levels demonstrated statistically significant differences on the basis of study groups, race, body mass index, multivitamin use, hemoglobin A_1c, serum creatinine level, and estimated glomerular filtration rate. In a multivariate linear regression model with all potential confounders, only multivitamin use remained significant (P < .001).ConclusionThis study suggests that patients with diabetes, especially those with PDR, have lower 25(OH)D levels than those without diabetes. (Endocr Pract. 2012; 18:185-193)     

The effects of aminoguanidine on retinopathy in STZ-induced diabetic rats

BackgroundThe accumulation of advanced glycated end products (AGEs) in retinal blood vessels is one of the major etiological factors contributing to diabetic retinopathy. Aminoguanidine (AG) is one of the most extensively used inhibitors of AGEs formation. The aim of this study was to investigate whether AG could protect the development of diabetic retinopathy through inhibition of AGEs.MethodsRat diabetes was induced by intraperitoneal injection with streptozotocin (STZ). AG was given to rats in drinking water. Retina was extracted 3 and 6 months following STZ and AG administration. Immunochemistry and transmission electron microscope were used to detect the expression of AGEs and retina morphology.ResultsExtensive staining of AGEs was detected in retinal blood vessels of 3- and 6-month diabetic rats, while no significant staining was found in the control non-diabetic retina or AG treated groups. Pericyte loss, endothelial cell proliferation, increased ratio of endothelial cells/pericytes, acellular capillaries and capillary occlusion were observed in the retina of 6-month diabetic rats. The increased electron density of retinal capillary basement membrane, mitochondrial swelling in pericytes and endothelial cells were also found in 6-month diabetic rats. The 3-month diabetic rats and the AG-treated rats did not have similar morphological changes compared to control group. The AGEs staining in AG-treated rats was still weakly positive.ConclusionsAGEs plays pivotal roles in diabetic retinopathy. AGE deposition occurs prior to retinal microvasculature changes. AG could prevent the onset and development of diabetic retinopathy through inhibition of AGEs.     

Automated Multi-Lesion Detection for Referable Diabetic Retinopathy in Indigenous Health Care

Diabetic Retinopathy (DR) is a complication of diabetes mellitus that affects more than one-quarter of the population with diabetes, and can lead to blindness if not discovered in time. An automated screening enables the identification of patients who need further medical attention. This study aimed to classify retinal images of Aboriginal and Torres Strait Islander peoples utilizing an automated computer-based multi-lesion eye screening program for diabetic retinopathy. The multi-lesion classifier was trained on 1,014 images from the São Paulo Eye Hospital and tested on retinal images containing no DR-related lesion, single lesions, or multiple types of lesions from the Inala Aboriginal and Torres Strait Islander health care centre. The automated multi-lesion classifier has the potential to enhance the efficiency of clinical practice delivering diabetic retinopathy screening. Our program does not necessitate image samples for training from any specific ethnic group or population being assessed and is independent of image pre- or post-processing to identify retinal lesions. In this Aboriginal and Torres Strait Islander population, the program achieved 100% sensitivity and 88.9% specificity in identifying bright lesions, while detection of red lesions achieved a sensitivity of 67% and specificity of 95%. When both bright and red lesions were present, 100% sensitivity with 88.9% specificity was obtained. All results obtained with this automated screening program meet WHO standards for diabetic retinopathy screening.     

玻璃体腔注药联合微创玻璃体切除治疗糖尿病视网膜病变的临床疗效研究

目的:探讨玻璃体腔注药联合微创玻璃体切除治疗糖尿病视网膜病变的临床疗效。方法:选择2014年1月至2016年1月在我院确诊并治疗的增生性糖尿病视网膜病变患者80例,共83只患眼,随机分为A、B两组。A组共42例患眼,接受25 G玻璃体微创手术;B组共41例患眼,在A组治疗的基础上给予玻璃体腔注射康柏西普。比较两组患者的手术情况、治疗前后最佳视力的矫正(Best-corrected visual acuity,BCVA)情况、视网膜厚度以及术后1个月不良反应的发生情况。结果:B组患者的手术时间较A组显著缩短(P0.05),且术中使用电凝的患眼、术中出血以及术中发生医源性裂隙的患眼比例显著低于A组(P0.05),新生血管消失的患眼比例显著高于A组(P0.05)。B组患者术后1个月和3个月的BVCA显著高于A组(P0.05),且术后视网膜的厚度显著薄于A组(P0.05),术后发生玻璃体积血和前方出血的患眼比例显著低于A组(P0.05)。结论:玻璃体腔注射康柏西普联合25G玻璃体微创切除术治疗增生性糖尿病视网膜病变的临床疗效显著,有利于患者术后视力以及视网膜恢复。