Insulin and risk of diabetic retinopathy in patients with type 2 diabetes mellitus: data from a meta-analysis of seven cohort studies

Retinopathy risk factors in patients with type 2 diabetes on liraglutide

Liraglutide, a glucagon-like peptide 1 receptor agonist, effectively treats type 2 diabetes(T2D) by lowering glucose levels, suppressing glucagon release, and promoting insulin secretion. Liraglutide has been shown to reduce body weight and glycated hemoglobin (HbA1c) levels and improve cardiovascular outcomes. However, evidence regarding the association between liraglutide and diabetic retinopathy in the Middle East is insufficient. Therefore, this study aimed to investigate the characteristics and risk factors of diabetic retinopathy in patients with T2D treated with liraglutide in Saudi Arabia. This retrospective cohort study was conducted on patients (≥14 years) with T2D treated with liraglutide between 2015 and 2021, who had a documented retinopathy assessment at baseline before liraglutide initiation and during follow-up, at King Abdulaziz Medical City (KAMC), Riyadh. Data collection included demographic information, retinopathy status, body mass index (BMI), and HbA1c level at baseline and follow-up after liraglutide use. The study included 181 patients with a mean age of 58.2 (9.8) years. Of these, 72.9% were females. At baseline, the median weight (interquartile range) was 88 (77-100) kg, diabetes duration was 19 (13-23.5) years, and HbA1c level was 9% (8-10%). Total of 69.6% were on insulin, 22.7% were on oral hypoglycemic agents, and 7.7% were on no other medications in addition to liraglutide. After a median of 2 years follow-up, both HbA1c level and weight decreased significantly (P < .001). Seventy-one of the 87 patients (81.6%) without retinopathy at baseline continued to show no retinopathy. Among patients with retinopathy at baseline, 25.5% showed improvement and 44.7% showed no change. In the multivariate binary mixed effect analysis, factors significantly associated with retinopathy were: use of insulin (odds ratio [OR]:2.68; 95% confidence interval [CI]: 1.18-6.09, P = .019), older age (OR:1.03; 95% CI: 1.00-1.06; P = .022), higher HbA1c level (OR:1.17; 95% CI: 1.02-1.34; P = .024), Hypertension (OR:2.56; 95% CI: 1.13-5.76; P=<.0001) and longer diabetes duration (OR:1.04; 95% CI: 1.00-1.08; P = .024). In conclusion, liraglutide use caused significant reductions in the HbA1c level and weight of patients with T2D. Most patients showed no change in retinopathy status after liraglutide use.

Drug Exposure As a Predictor in Diabetic Retinopathy Risk Prediction Models-A Systematic Review and Meta-Analysis

PURPOSE

To conduct a systematic review to assess drug exposure handling in diabetic retinopathy (DR) risk prediction models, a network-meta-analysis to identify drugs associated with DR and a meta-analysis to determine which drugs contributed to enhanced model performance.

DESIGN

Systematic review and meta-analysis.

METHODS

We included studies presenting DR models incorporating drug exposure as a predictor. We searched EMBASE, MEDLINE, and SCOPUS from inception to December 2023. We evaluated the quality of studies using the Prediction model Risk of Bias Assessment Tool and certainty using GRADE. We conducted network meta-analysis and meta-analysis to estimate the odds ratio (OR) and pooled C-statistic, respectively, and 95% confidence intervals (CI) (PROSPERO: CRD42022349764).

RESULTS

Of 5,653 records identified, we included 28 studies of 678,837 type 1 or 2 diabetes participants, of which 38,579 (5.7%) had DR. A total of 19, 3, and 7 studies were at high, unclear, and low risk of bias, respectively. Drugs included in models as predictors were: insulin (n = 24), antihypertensives (n = 5), oral antidiabetics (n = 12), lipid-lowering drugs (n = 7), antiplatelets (n = 2). Drug exposure was modelled primarily as a categorical variable (n = 23 studies). Two studies handled drug exposure as time-varying covariates, and one as a time-dependent covariate. Insulin was associated with an increased risk of DR (OR = 2.50; 95% CI: 1.61-3.86). Models that included insulin (n = 9) had a higher pooled C-statistic (C-statistic = 0.84, CI: 0.80-0.88), compared to models (n = 9) that incorporated a combination of drugs alongside insulin (C-statistic = 0.79, CI: 0.74-0.84), as well as models (n = 3) not including insulin (C-statistic = 0.70, CI: 0.64-0.75). Limitations include the high risk of bias and significant heterogeneity in reviewed studies.

CONCLUSION

This is the first review assessing drug exposure handling in DR prediction models. Drug exposure was primarily modelled as a categorical variable, with insulin associated with improved model performance. However, due to suboptimal drug handling, associations between other drugs and model performance may have been overlooked. This review proposes the following for future DR prediction models: (1) evaluation of drug exposure as a variable, (2) use of time-varying methodologies, and (3) consideration of drug regimen details. Improving drug exposure handling could potentially unveil novel variables capable of significantly enhancing the predictive capability of prediction models.

Evaluation of systemic medications associated with diabetic retinopathy: a nested case-control study from the UK Biobank

AIMS

This study aims to investigate the associations between commonly used systemic medications and diabetic retinopathy (DR).

METHODS

Individuals with linked primary care prescription data from the UK Biobank were included. Cases were defined as individuals with a Hospital Episode Statistics-coded or primary care recorded diagnosis of DR or self-reported DR. Controls were matched for age, sex, glycosylated haemoglobin, duration of diabetes mellitus (DM), hypertension status and cardiovascular disease status. ORs and 95% CIs were calculated using conditional univariate and multivariable logistic regression models.

RESULTS

A total of 3377 case subjects with DR were included in the study and matched with 3377 control subjects. In multivariable logistic regression, increased odds of incident DR were observed for exposure to short-acting insulins (OR 1.63; 95% CI 1.22 to 2.18), medium-acting insulins (OR 2.10; 95% CI 1.60 to 2.75), sulfonylureas (OR 1.30; 95% CI 1.16 to 1.46). Instead, the use of fibrates (OR 0.71; 95% CI 0.53 to 0.94) and Cox-2 inhibitors (OR 0.68; 95% CI 0.58 to 0.79) was associated with decreased odds of incident DR. Dose-response relationships were observed for all five drug categories (all p<0.05).

CONCLUSIONS

This study comprehensively investigated the associations between systemic medication use and DR and found significant associations between the use of short-acting insulins, medium-acting insulins and sulfonylureas with increased odds of incident DR. In contrast, fibrates and Cox-2 inhibitors were associated with decreased odds of incident DR. These findings may provide valuable insights into DM medication management and serve as a reference for the prevention of DR in patients with DM.

Risk factors for diabetic retinopathy, diabetic macular edema, and sight-threatening diabetic retinopathy

OBJECTIVE

To identify the risk factors for the development of diabetic retinopathy (DR), diabetic macular edema (DME), and sight-threatening DR (STDR) based on a city-wide diabetes screening program.

RESEARCH DESIGN AND METHODS

Diabetic patients were prospectively recruited between June 2016 and December 2022. All patients underwent dilated fundus photography centered on the disc and macula or macular spectral domain optical coherence tomography (SD-OCT) scan. Complete medical history was documented. Systematic examination, blood analysis, and urinalysis were performed. Multivariate logistic regression analysis adjusting for age and sex was conducted.

RESULTS

Out of 7274 diabetic patients, 6840 had gradable images, among which 3054 (42.0%) were graded as DR, 1153 (15.9%) as DME, and 1500 (20.6%) as STDR. The factors associated with DR, DME, and STDR included younger age (odds ratio [OR]: 0.96, 0.97, and 0.96 respectively), lower BMI (OR: 0.97, 0.95, and 0.95 respectively), longer duration of diabetes (OR: 1.07, 1.03, and 1.05 respectively) and positive of urinary albumin (OR: 2.22, 2.56, and 2.88 respectively). Other associated factors included elevated blood urea nitrogen (OR: 1.22, 1.28, and 1.27 respectively), higher LDL-cholesterol, lower blood hemoglobin (OR: 0.98, 0.98, and 0.98), insulin intake, presence of diabetic foot pathologies and diabetic peripheral neuropathy. We also identified novel risk factors, including high serum potassium (OR: 1.37, 1.46, and 1.55 respectively), high-serum sodium (OR: 1.02, 1.02, and 1.04 respectively). Better family income was a protective factor for DR, DME, and STDR. Alcohol consumption once a week was also identified as a protective factor for DR.

CONCLUSIONS

Similar risk factors for DR, DME, and STDR were found in this study. Our data also indicates high serum sodium, high serum potassium, low blood hemoglobin, and level of family income as novel associated factors for DR, DME, and STDR, which can help with DR monitoring and management.

Diabetic Disease of the Eye in Canada: Consensus Statements from a Retina Specialist Working Group

Despite advances in systemic care, diabetic disease of the eye (DDE) remains the leading cause of blindness worldwide. There is a critical gap of up-to-date, evidence-based guidance for ophthalmologists in Canada that includes evidence from recent randomized controlled trials. Previous guidance has not always given special consideration to applying treatments and managing DDE in the context of the healthcare system. This consensus statement aims to assist practitioners in the field by providing a spectrum of acceptable opinions on DDE treatment and management from recognized experts in the field. In compiling evidence and generating consensus, a working group of retinal specialists in Canada addressed clinical questions surrounding the four themes of disease, patient, management, and collaboration. The working group reviewed literature representing the highest level of evidence on DDE and shared their opinions on topics surrounding the epidemiology and pathophysiology of diabetic retinopathy and diabetic macular edema; diagnosis and monitoring; considerations around diabetes medication use; strategic considerations for management given systemic comorbidities, ocular comorbidities, and pregnancy; treatment goals and modalities for diabetic macular edema, non-proliferative and proliferative diabetic retinopathy, and retinal detachment; and interdisciplinary collaboration. Ultimately, this work highlighted that the retinal examination in DDE not only informs the treating ophthalmologist but can serve as a global index for disease progression across many tissues of the body. It highlighted further that DDE can be treated regardless of diabetic control, that a systemic approach to patient care will result in the best health outcomes, and prevention of visual complications requires a multidisciplinary management approach. Ophthalmologists must tailor their clinical approach to the needs and circumstances of individual patients and work within the realities of their healthcare setting.

An analysis of the relationship between ABCC8 and KCNJ11 gene polymorphisms and diabetic retinopathy in Turkish population

BACKGROUND

Diabetic retinopathy (DR) occurs due to high blood glucose damage to the retina and leads to blindness if left untreated. KATP and related genes (KCNJ11 and ABCC8) play an important role in insulin secretion by glucose-stimulated pancreatic beta cells and the regulation of insulin secretion. KCNJ11 E23K (rs5219), ABCC8-3 C/T (rs1799854), Thr759Thr (rs1801261) and Arg1273Arg (rs1799859) are among the possible related single nucleotide polymorphisms (SNPs). The aim of this study is to find out how DR and these SNPs are associated with one another in the Turkish population.

MATERIALS AND METHODS

This study included 176 patients with type 2 diabetes mellitus without retinopathy (T2DM-rp), 177 DR patients, and 204 controls. Genomic DNA was extracted from whole blood, and genotypes were determined by the PCR-RFLP method.

RESULTS

In the present study, a significant difference was not found between all the groups in terms of Arg1273Arg polymorphism located in the ABCC8 gene. The T allele and the TT genotype in the -3 C/T polymorphism in this gene may have a protective effect in the development of DR (p = 0.036 for the TT genotype; p = 0.034 for T allele) and PDR (p = 0.042 and 0.025 for the TT genotype). The AA genotype showed a significant increase in the DR group compared to T2DM-rp in the KCNJ11 E23K polymorphism (p = 0.046).

CONCLUSIONS

Consequently, the T allele and TT genotype in the -3 C/T polymorphism of the ABCC8 gene may have a protective marker on the development of DR and PDR, while the AA genotype in the E23K polymorphism of the KCNJ11 gene may be effective in the development of DR in the Turkish population.

Relationship Between Disease and Treatment Factors in Diabetes With Vision Difficulty: A Cross-Sectional, Population-Based Analysis

BACKGROUND AND OBJECTIVE

Relationships between disease and treatment factors of diabetes and vision difficulty remain largely unknown. This study investigated the relationship between disease and treatment factors in diabetes and participants' self-reported vision difficulty.

PATIENTS AND METHODS

This was a cross-sectional, population-based analysis. Data from the National Health Interview Survey was used and analyzed through univariable and multivariable logistic regression.

RESULTS

From the 29,464 included participants, logistic regression showed increased odds of self-reported vision difficulty among participants with diabetes (odds ratio [OR] = 2.14, P < 0.001), prediabetes (OR = 1.95, P < 0.001), or gestational diabetes (OR = 1.54, P < 0.001) compared to participants without diabetes. Those who reported having diabetes for more than a year had higher odds of vision difficulty (OR = 1.97, P = 0.02), as did those who were taking insulin (OR = 1.62, P < 0.001), those who had taken less insulin to save money within the past year (OR = 1.87, P = 0.01), and those who reported experiencing diabetes-related stress (OR = 2.14, P < 0.001).

CONCLUSIONS

Duration of diabetes, diabetes-related stress, and taking less insulin than recommended to save money were associated with vision difficulty. [Ophthalmic Surg Lasers Imaging Retina 2024;55:142-153.].

Associations of antidiabetic drugs with diabetic retinopathy in people with type 2 diabetes: an umbrella review and meta-analysis

Background

Diabetic retinopathy (DR) is the most frequent complication of type 2 diabetes and remains the leading cause of preventable blindness. Current clinical decisions regarding the administration of antidiabetic drugs do not sufficiently incorporate the risk of DR due to the inconclusive evidence from preceding meta-analyses. This umbrella review aimed to systematically evaluate the effects of antidiabetic drugs on DR in people with type 2 diabetes.

Methods

A systematic literature search was undertaken in Medline, Embase, and the Cochrane Library (from inception till 17th May 2022) without language restrictions to identify systematic reviews and meta-analyses of randomized controlled trials or longitudinal studies that examined the association between antidiabetic drugs and DR in people with type 2 diabetes. Two authors independently extracted data and assessed the quality of included studies using the AMSTAR-2 (A MeaSurement Tool to Assess Systematic Reviews) checklist, and evidence assessment was performed using the GRADE (Grading of recommendations, Assessment, Development and Evaluation). Random-effects models were applied to calculate relative risk (RR) or odds ratios (OR) with 95% confidence intervals (CI). This study was registered with PROSPERO (CRD42022332052).

Results

With trial evidence from 11 systematic reviews and meta-analyses, we found that the use of glucagon-like peptide-1 receptor agonists (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), or dipeptidyl peptidase-4 inhibitors (DPP-4i) was not statistically associated with the risk of DR, compared to either placebo (RR: GLP-1 RA, 0.98, 0.89-1.08; SGLT-2i, 1.00, 95% CI 0.79-1.27; DPP-4i, 1.17, 0.99-1.39) or other antidiabetic drugs. Compared to other antidiabetic drugs, meglitinides (0.34, 0.01-8.25), SGLT-2i (0.73, 0.10-5.16), thiazolidinediones (0.92, 0.67-1.26), metformin (1.15, 0.81-1.63), sulphonylureas (1.24, 0.93-1.65), and acarbose (4.21, 0.44-40.43) were not statistically associated with the risk of DR. With evidence from longitudinal studies only, insulin was found to have a higher risk of DR than other antidiabetic drugs (OR: 2.47, 95% CI: 2.04-2.99).

Conclusion

Our results indicate that antidiabetic drugs are generally safe to prescribe regarding the risk of DR among people with type 2 diabetes. Further robust and large-scale trials investigating the effects of insulin, meglitinides, and acarbose on DR are warranted.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=332052, identifier CRD42022332052.

Retinal Microvascular Density and Perfusion during an Insulin-Induced Hypoglycemia Episode: A Warning Call

Aim

To evaluate retinal vascular perfusion and density by optical coherence tomography angiography (OCTA) before, during, and after hypoglycemia in individuals with diabetes mellitus with or without diabetic retinopathy (DR).

Methods

A focused clinical history was performed, followed by an ophthalmological examination to document retinopathy status. OCTA was performed at baseline, at hypoglycemia, and at glucose normalization. Eye tracking and eye alignment devices on the platform were used to obtain a macular thickness cube (512 × 128) and vascular perfusion and density protocols of 3 × 3 mm. Retinal vascular reactivity was analyzed with superficial plexus vascular perfusion and density protocols on OCTA.

Results

Fifty-two participants encompassing 97 eyes fulfilled the eligibility criteria. Their mean age was 42.9 ± 15.1 years (range, 22 to 65), and 20 (38.2%) were men. We found a statistically significant difference in vascular perfusion and density when comparing all groups at baseline. The controls had higher vascular perfusion and density values than the cases. Vascular perfusion and density were significantly reduced in all groups during the hypoglycemia episode, except for vascular density in DR cases.

Conclusion

Acute hypoglycemia significantly alters the retinal vascularity in DM patients with and without DR, suggesting that repeated episodes of acute hypoglycemia could exacerbate retinopathy in the long term.

Prevalence and Determinants of Diabetic Retinopathy Among Type 2 Diabetic Patients in Saudi Arabia: A Systematic Review

Diabetic retinopathy (DR) is a preventable complication of diabetes; however, it is a serious one if not early recognized and properly managed as it can lead to visual impairment. This review aimed to summarize the prevalence and determinants of DR among type 2 diabetic patients in Saudi Arabia. Eligible articles for this systematic review were quantitative observational studies that were English-published between 2015 and 2021, peer-reviewed, and conducted on patients with type 2 diabetes mellitus (DM). The studies were obtained by searching PubMed/Medline, ScienceDirect, Cochrane Library Database, and Google Scholar. The risk of bias was assessed using the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies. Out of 16 preliminary studies, 12 were eligible for inclusion in this systematic review. One study was a chart review, one was a prospective study, and the remaining were cross-sectional studies. Regarding the study tool, retinopathy was diagnosed by an ophthalmologist using fundus photography and/or slit-lamp examination in most of the studies (n=7). However, some studies reported obtaining data from patient interviews and medical files (n=4). Concerning the outcome, an overall high prevalence of DR (ranging between 6.25% and 88.1%) and some significant associated risk factors were determined, including longer duration of diabetes, older age, poor blood pressure control, poor glycemic control, and physical inactivity. Most studies showed moderate overall quality. In conclusion, DR is a common complication of type 2 diabetes in Saudi Arabia. Some avoidable risk factors are identified, through which the doctors can identify patients at high risk of DR through early screening and can, thus, initiate prompt treatment to reduce the risk of vision deterioration.

Direct medical cost and medications for patient of diabetes retinopathy in Beijing, China, 2016 to 2018

AIMS

Medications and costs of drug for diabetic retinopathy in outpatient in China have not been evaluated. The purpose of this study was to evaluate the hypoglycemic drugs and medical costs of diabetic retinopathy patients in the Beijing medical insurance system, analyze the characteristics of outpatient treatment, and investigate the changes in the quantity and cost of hypoglycemic drugs from 2016 to 2018 METHODS: This is a retrospective observational study, including diabetic patients with outpatient records in Beijing medical insurance from 2016 to 2018. Data on oral hypoglycemic drugs , insulin and non-hypoglycemic drugs, complications, treatment strategies, and annual medical costs were recorded Results: A total of 2,853,036 diabetic patients in Beijing medical insurance were enrolled in this study. 4.19%-4.67% of patients were diagnosed with retinopathy. Patients with retinopathy have more diabetic complications (1.65±0.71 vs 0.18±0.44. pp<.0001),and use more drugs (5.11±2.60 vs 3.85±2.34, pp <.0001), the annual total drug cost is also higher (¥ 13836±11244 vs ¥ 10030±9375, pp <.0001). The numbers of medication in retinopathy patients increased(5.11±2.60 vs 4.95±2.57, pp <.0001), and the annual total drug cost (¥13836±11244 vs ¥15642±13344, pp <.0001)decreased in 2018 compared with 2016.

CONCLUSIONS

Patients with retinopathy were associated with more complications. Compared with patients without retinopathy, the number of medications and total medical costs were significantly increased. From 2016 to 2018, there was an increase in the number of medication treatments for patients with retinopathy, but a decrease in cost.

Development and validation of a diabetic retinopathy risk prediction model for middle-aged patients with type 2 diabetes mellitus

Objectives

The study aims to establish a predictive nomogram of diabetic retinopathy(DR) for the middle-aged population with type 2 diabetes mellitus (T2DM).

Methods

This retrospective study screened 931 patients with T2DM between 30 and 59 years of age from the 2011-2018 National Health and Nutrition Examination Survey database. The development group comprised 704 participants from the 2011-2016 survey, and the validation group included 227 participants from the 2017-2018 survey. The least absolute shrinkage and selection operator regression model was used to determine the best predictive variables. The logistic regression analysis built three models: the full model, the multiple fractional polynomial (MFP) model, and the stepwise (stepAIC) selected model. Then we decided optimal model based on the receiver operating characteristic curve (ROC). ROC, calibration curve, Hosmer-Lemeshow test, and decision curve analysis (DCA) were used to validate and assess the model. An online dynamic nomogram prediction tool was also constructed.

Results

The MFP model was selected to be the final model, including gender, the use of insulin, duration of diabetes, urinary albumin-to-creatinine ratio, and serum phosphorus. The AUC was 0.709 in the development set and 0.704 in the validation set. According to the ROC, calibration curves, and Hosmer-Lemeshow test, the nomogram demonstrated good coherence. The nomogram was clinically helpful, according to DCA.

Conclusion

This study established and validated a predictive model for DR in the mid-life T2DM population, which can assist clinicians quickly determining who is prone to develop DR.

Semiparametric modelling of diabetic retinopathy among people with type II diabetes mellitus

BACKGROUND

The proportion of patients with diabetic retinopathy (DR) has grown with increasing number of diabetes mellitus patients in the world. It is among the major causes of blindness worldwide. The main objective of this study was to identify contributing risk factors of DR among people with type II diabetes mellitus.

METHOD

A sample of 191 people with type II diabetes mellitus was selected from the Black Lion Specialized Hospital diabetic unit from 1 March 2018 to 1 April 2018. A multivariate stochastic regression imputation technique was applied to impute the missing values. The response variable, DR is a categorical variable with two outcomes. Based on the relationship derived from the exploratory analysis, the odds of having DR were not necessarily linearly related to the continuous predictors for this sample of patients. Therefore, a semiparametric model was proposed to identify the risk factors of DR.

RESULT

From the sample of 191 people with type II diabetes mellitus, 98 (51.3%) of them had DR. The results of semiparametric regression model revealed that being male, hypertension, insulin treatment, and frequency of clinical visits had a significant linear relationships with the odds of having DR. In addition, the log- odds of having DR has a significant nonlinear relation with the interaction of age by gender (for female patients), duration of diabetes, interaction of cholesterol level by gender (for female patients), haemoglobin A1c, and interaction of haemoglobin A1c by fasting blood glucose with degrees of freedom [Formula: see text], respectively. The interaction of age by gender and cholesterol level by gender appear non significant for male patients. The result from the interaction of haemoglobin A1c (HbA1c) by fasting blood glucose (FBG) showed that the risk of DR is high when the level of HbA1c and FBG were simultaneously high.

CONCLUSION

Clinical variables related to people with type II diabetes mellitus were strong predictive factors of DR. Hence, health professionals should be cautious about the possible nonlinear effects of clinical variables, interaction of clinical variables, and interaction of clinical variables with sociodemographic variables on the log odds of having DR. Furthermore, to improve intervention strategies similar studies should be conducted across the country.

Nomogram-based prediction of clinically significant macular edema in diabetes mellitus patients

AIMS

The aim of the study was to construct and validate a risk nomogram for clinically significant macular edema (CSME) prediction in diabetes mellitus (DM) patients using systemic variables.

METHODS

In this retrospective study, DM inpatients who underwent routine diabetic retinopathy screening were recruited and divided into training and validation sets according to their admission date. Ninety-three demographic and systemic variables were collected. The least absolute shrinkage and selection operator was used to select the predictive variables from the training set. The selected variables were used to construct the CSME prediction nomogram. Internal and external validations were performed. The C-index, calibration curve and decision curve analysis (DCA) were reported.

RESULTS

A total of 349 patients were divided into the training set (240, 68.77%) and the validation set (109, 31.23%). The presence of diabetic peripheral neuropathy (DPN) symptoms, uric acid, use of insulin only or not for treatment, insulin dosage, urinary protein grade and disease duration were chosen for the nomogram. The C-index of the prediction nomogram was 0.896, 0.878 and 0.837 in the training set, internal validation and external validation, respectively. The calibration curves of the nomogram showed good agreement between the predicted and actual outcomes. DCA demonstrated that the nomogram was clinically useful.

CONCLUSIONS

A nomogram with good performance for predicting CSME using systemic variables was developed. It suggested that DPN symptoms and renal function may be crucial risk factors for CSME. Moreover, this nomogram may be a convenient tool for non-ophthalmic specialists to rapidly recognize CSME in patients and to transfer them to ophthalmologists for early diagnosis and treatment.

Associations between diabetic retinopathy and modifiable risk factors: An umbrella review of meta-analyses

AIMS

Several modifiable risk factors have been meta-analysed for diabetic retinopathy (DR), such as physical activity and vitamin D status. To date, these factors have not been systematically aggregated and the credibility of evidence assessed. Therefore, the aim of this umbrella review was to aggregate all modifiable risks of DR and assess the credibility of the evidence.

METHODS

An umbrella review of meta-analyses was undertaken. For each meta-analytic association, random-effects effect size, 95% confidence intervals (CIs), heterogeneity, small-study effects, excess significance bias and 95% prediction intervals were calculated. The credibility of significant evidence (p < 0.05) was graded from I to IV, using pre-defined criteria.

RESULTS

After initial searches, 13 studies were included covering 34 independent outcomes (total participants = 824,372). Positive associations were found between insulin usage and diabetic macular oedema (RR = 4.5; 95% CI 3.1-6.6), and DR risk (RR = 2.3; 95% CI 1.4-3.9) in people with type 2 diabetes. Vitamin D deficiency was associated with DR risk (OR = 2.8; 95% CI 1.1-7.1), as was obesity (RR = 1.34; 95% CI 1.06-1.68) and sedentary behaviour (RR = 1.22; 95%CI 1.03-1.44). Intensive blood pressure targets (RR = 0.8 95%CI 0.8-1.0), and moderate physical activity (RR = 0.69; 95%CI 0.53-0.91) yielded significant protective associations with DR.

CONCLUSIONS

People with type 2 diabetes on insulin have a high risk of macular oedema and DR. Vitamin D deficiency yielded almost three times greater odds of DR, while intensive blood pressure control reduces DR risk by 20% and moderate physical activity by 31%. Healthcare professionals should use this evidence to identify those people most at risk to ensure that proper treatment and healthy lifestyles are recommended.

Coffee consumption and diabetic retinopathy in adults with diabetes mellitus

We aimed to evaluate the association between the prevalence of diabetic retinopathy (DR) and coffee consumption in a Korean population. This cross-sectional study was based on data from the 2008–2011 Korean National Health and Nutrition Survey. Among 37,753 survey participants, the data of 1350 subjects with type 2 diabetes who underwent DR examination were analyzed. DR was graded using the modified Airlie House classification system. Coffee consumption data were obtained through food frequency questionnaires and categorized into four groups: almost none, < 1 cup/day, 1 cup/day, and ≥ 2 cups/day. The relationship between DR and coffee consumption was evaluated using multivariable logistic regression models adjusted for age, sex, education, occupation, income, smoking, alcohol intake, body mass index, physical activity, hypertension, dyslipidemia, diabetes duration, and glycated hemoglobin. The prevalence of DR was 20.0%. Non-proliferative DR was observed in 87.8% of all DR patients, and proliferative DR in 12.2%. The prevalence of DR and vision-threatening DR showed a significantly decreasing tendency according to daily coffee consumption (P for trend 0.025 and 0.005, respectively) after adjustment for possible confounders. This tendency was more prominent in those aged < 65 years (P for trend 0.005 and 0.003, respectively). Our findings suggest coffee consumption might be associated with DR reduction especially in Koreans with diabetes mellitus aged < 65 years.

Iris thickness measurements in patients with diabetic retinopathy

Purpose:

The aim of the study was to investigate iris alterations in diabetic retinopathy (DR).

Methods:

Sixty-nine eyes of 69 patients were recruited and three groups of patients were examined: proliferative DR ( n = 25), non-proliferative DR ( n = 21) and healthy controls ( n = 23). Macular optical coherence tomography (OCT), anterior segment iris OCT, and slit lamp digital camera photographs were taken. The thicknesses of the iris at a distance of 1 mm, 2 mm, and 3 mm from pupil margin were measured via iris OCT. Iris crypt count, furrow extent, color tone and collarette/diameter ratio were measured by means of anterior segment photography. Visual acuity, refractive error, intraocular pressure, and numbers of intravitreal injections were also recorded.

Results:

The iris thickness measurements at 1 mm from pupil margin were significantly correlated with the macular thickness measurements ( r = 0.32, p = 0.016). In the proliferative DR group, total number of injections were significantly correlated with the iris thickness measurements at 1 mm ( r = 0.25, p = 0.04). The iris thickness measurements at distances 1 mm, 2 mm, and 3 mm from the pupil margin were similar in all of the groups ( p > 0.05). Iris thickness did not correlate with age, intra-ocular pressure and collarette iris ratio in all the participants ( p > 0.05).

Conclusion:

Iris thickness is similar in diabetic patients and healthy controls. Meanwhile, iris thickness near the pupillary margin is positively correlated with macular thickness.

Berberine improves insulin-induced diabetic retinopathy through exclusively suppressing Akt/mTOR-mediated HIF-1α/VEGF activation in retina endothelial cells

Background: Insulin therapy is the major treatment of glycaemic control in type I diabetes mellitus (DM) and advanced type II DM patients who fail to respond to oral hypoglycemic agents. Nonetheless, insulin therapy is deemed unsuccessful in controlling the incidence of diabetic retinopathy (DR) and is likely a risk factor. Berberine, an isoquinoline alkaloid, has caught great attention towards its anti-diabetic mechanisms. This study aims to investigate the effect of berberine in decelerating DR progression in insulin-treated DM.

Methods: To better understand the therapeutic potential of berberine in the presence of insulin, we elaborated the action of mechanism whether berberine inhibited retinal expression of HIF-1α and VEGF through regulating AKT/mTOR pathway. Suppression of insulin-induced neovasculature of retina endothelial cells by berberine was also studied. Lastly, the in vivo efficacy and safety of berberine as adjuvant therapy for the treatment of DR were systemically investigated in experimental type I and type II DM mice with insulin treatment.

Results: Among various types of retinal cells, the activity of HIF-1α and VEGF in retinal endothelial cells could be particularly and exclusively stimulated by insulin intervention, which could be inhibited by berberine treatment in a dose- and time-dependent manner. Berberine suppressed Akt/mTOR activity in these cells, and restoration of Akt/mTOR signalling attenuated berberine's inhibition on HIF-1α and VEGF expression. Berberine suppressed the progression of DR in experimental type I and type II diabetic mice receiving insulin therapy.

Conclusion: Berberine improves insulin-induced diabetic retinopathy in type I and II diabetes through inhibiting insulin-induced activation of retinal endotheliocytes via Akt/mTOR/ HIF-1α/VEGF pathway.

Metformin-Insulin versus Metformin-Sulfonylurea Combination Therapies in Type 2 Diabetes: A Comparative Study of Glycemic Control and Risk of Cardiovascular Diseases in Addis Ababa, Ethiopia

OBJECTIVE

This study aimed to compare glycemic control and risk of cardiovascular outcomes of metformin-insulin versus metformin-sulfonylurea combination therapies in type 2 diabetes mellitus.

METHODS

We conducted a comparative cross-sectional study in five tertiary level hospitals in Addis Ababa, Ethiopia. We enrolled 321 patients with type 2 diabetes mellitus who were on continuous treatment follow-up on either metformin-insulin or metformin-sulfonylurea combination therapy. We interviewed the participants and reviewed their medical records to investigate medication efficacy, safety, and adherence. The primary outcome measure was glycemic control and the secondary outcome measures were composite cardiovascular outcomes.

RESULTS

Of the total participants enrolled, 50.5% (n = 162) were those who received metformin-insulin and 49.5% (n = 159) metformin-sulfonylurea combination therapies for a median of 48 months follow-up. The reduction of Hb1Ac levels was comparable between the metformin-insulin (-1.04 ± 0.96%) and metformin-sulfonylurea (-1.02 ± 1.03%), p = 0.912. Patients who received metformin-sulfonylurea had 4.3 times more likely to have achieved target HbA1c level compared to those who received metformin-insulin, p < 0.001, adjusted odds ratio (AOR) with 95% CI = 4.31[1.79-10.32]. Risk of composite cardiovascular outcomes was higher in metformin-insulin group (40.5% versus 34.0%), p = 0.021. Co-morbidities, body mass index, systolic blood pressure, and HbA1c had a significant association with composite cardiovascular outcomes. Reductions of bodyweight, HDL-C, LDL-C, triglycerides levels, and microvascular complications were different between the two groups, p < 0.05.

CONCLUSION

High proportion of patients who received metformin-sulfonylurea achieved target HbA1c level and had less composite cardiovascular outcomes compared to those who received metformin-insulin. However, these findings have to be confirmed with randomized control trials to determine risks associated with insulin use, while efficacy is maintained as second-line treatment in patients with type 2 diabetes mellitus.

Effect of insulin treatment on pulsatility ratio and resistance index of the retinal artery in patients with type 2 diabetes

This study aimed to evaluate whether long-term insulin treatment is associated with abnormalities in retinal circulation in type 2 diabetic patients. We evaluated 19 eyes of nondiabetic individuals and 68 eyes of type 2 diabetic patients. The eyes of diabetic patients were classified into two groups according to the presence or absence of long-term insulin therapy. We used a Doppler optical coherence tomography flowmeter to measure diameter, velocity, and blood flow in the major temporal retinal artery. The pulsatility ratio (PR) and resistance index (RI), indices of vascular rigidity, were calculated from the blood velocity profile. PR and RI were significantly elevated in type 2 diabetic patients compared with nondiabetic subjects (P < 0.05). In type 2 diabetes patients, PR and RI were significantly higher in patients receiving long-term insulin treatment than in those without (P < 0.01). There was a significant difference in velocity (P < 0.05), but not diameter and blood flow, between nondiabetic subjects and type 2 diabetes patients. No significant difference in diameter, velocity, or blood flow was observed between the groups with and without long-term insulin treatment. Long-term insulin treatment can affect PR and RI, which might be associated with vascular rigidity of the retinal artery in patients with type 2 diabetes.

The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy-A Review

BACKGROUND

Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world's population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes.

AIM

The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR.

MATERIAL AND METHODS

An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR.

RESULTS

A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period.

CONCLUSIONS

It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.

The effect of diabetes on corneal endothelium: a meta-analysis

BACKGROUND

This research was conducted with the aim to determine the effect of diabetes mellitus on corneal endothelial cells.

METHODS

The terms: ("diabetes mellitus" or "diabetes" or "diabetic") and ("corneal endothelium" or "cornea" or "Corneas") searched in Pubmed, Embase, Cochrane, and Web of science until August 2019. The included types of studies contained observational studies. The standard mean difference (SMD) which was deemed as main size effects for continuous data was calculated by means and standard deviations. The data on corneal endothelial cell density (ECD), mean cell area (MCA), cell area variation coefficient (CV) and percentage of hexagonal cells (HEX) included in the study were collected and analyzed using stata15.1.

RESULTS

The final 16 cross-sectional studies and 2 case-control studies were included for the meta-analysis. Meta-analysis revealed that diabetes mellitus could reduce ECD (SMD = - 0.352, 95% CI -0.538, - 0.166) and the HEX (SMD = - 0.145, 95% CI -0.217, - 0.074), in addition to increasing CV (SMD = 0.195, 95% CI 0.123, 0.268). Nevertheless, there was no statistically significant differences observed when combining MCA (SMD = 0.078, 95% CI -0.022, 0.178). In subgroup analysis, Type 2 diabetes patients owned less corneal ECD (P < 0.05). Moreover the same results also found during the subgroup form Asia, Europe and American. The meta-regression revealed the type of diabetes mellitus might be contributing to heterogeneity. (P = 0.008). The results indicated a significant publication bias for studies, with combined CV (Begg's test, P = 0.006; Egger's test, P = 0.005) and merged combined HEX (Begg's test, P = 0.113; Egger's test, P = 0.024).

CONCLUSIONS

As indicated by meta-analysis, diabetes mellitus could cause a detrimental effect on corneal endothelium health. Diabetes mellitus contributed to the instability of corneal endothelium during the analysis. Therefore, further research is considered necessary to confirm our research results.

TRIAL REGISTRATION

CED 42019145858 .

Diabetic retinopathy in the Eastern Morocco: Different stage frequencies and associated risk factors

Diabetes is a major cause of morbidity and mortality worldwide. It can affect many organs and, over time, leads to serious complications. Diabetic retinopathy (DR), a specific ocular complication of diabetes, remains the leading cause of vision loss and vision impairment in adults. This work is the first in Eastern Morocco aimed at identifying the different stages of DR and to determine their frequencies and associated risk factors. It is a case-control study conducted from December 2018 to July 2019 at the ophthalmology department of Al-Irfane Clinic (Oujda). Data were obtained from a specific questionnaire involving 244 diabetic patients (122 cases with retinopathy vs 122 controls without retinopathy). All results were analyzed by the EPI-Info software. This study shows a predominance of proliferative diabetic retinopathy (PDR) with 57.4% of cases (uncomplicated proliferative diabetic retinopathy (UPDR): 23.8%; complicated proliferative diabetic retinopathy (CPDR): 33.6%). The non-proliferative diabetic retinopathy (NPDR) represents 42.6% (minimal NPDR: 8.2%; moderate NPDR: 26.2%; severe NPDR: 8.2%). The determinants of DR were insulin therapy, high blood pressure, poor glycemic control and duration of diabetes. Regarding the chronological evolution, retinopathy precedes nephropathy. Diabetic nephropathy (DN) was present in 10.6% of cases especially in patients with PDR. In summary, the frequency of PDR was higher than that of NPDR. DR appears before DN with a high frequency of DN in patients with PDR. Good glycemic control and blood pressure control, as well as early diagnosis are the major preventive measures against DR.

Correlates of diabetic retinopathy in type 2 diabetes mellitus patients in Makkah Al-Mukarramah, Saudi Arabia

BACKGROUND:

Diabetic retinopathy (DR) is a serious complication of diabetes that can cause visual impairment. The objective of this study was to estimate the prevalence and identify the determinants of DR in type 2 diabetes mellitus patients attending the diabetic center at Al-Noor Specialist Hospital in Makkah, Saudi Arabia.

MATERIALS AND METHODS:

A cross-sectional study was conducted in a sample of type 2 diabetic patients registered at the diabetic center at Al-Noor Specialist Hospital. Data was collected using a validated self-administered questionnaire. Grading of DR was done by slit-lamp examination and colored fundus photographs. Descriptive analysis included frequency and percentage for categorical variables, and mean, median, standard deviation (SD), and interquartile range, for continuous variables. Chi-square test used to test for association between two categorical variables; Student's t-test or Mann-Whitney U test as appropriate employed to compare continuous variable between two groups. Logistic regression analysis was utilized to identify correlates of DR after controlling for confounders.

RESULTS:

The study comprised 251 type 2 diabetic patients aged between 28 and 80 years, with an arithmetic mean of 56.8 and standard deviation of ±9.9 years. The prevalence of DR was 54.6%; mild nonproliferative (NP) type was present in 52.6% of the patients with DR, whereas severe NP type was present in 15.3% of them; the proliferative type was present in only 4.4% of those with DR. Multivariate logistic regression analysis revealed that patients who had had diabetes for a 11 to 16 years (adjusted odds ratio [AOR] = 3.52, P = 0.035), patients who did not take daily medications on time (AOR = 9.75, P = 0.008), patients who did not go for fundus examination annually (AOR = 3.62, P = 0.011), and patients with uncontrolled diabetes (AOR = 12.18, P < 0.001) were at higher significant risk for DR. Patients not treated with insulin were 70% less likely to develop DR (AOR = 0.30, P = 0.015). An increase of one unit in body mass index was significantly associated with increase in the probability of developing DR by 11% (AOR = 1.11, P = 0.024).

CONCLUSION:

DR is very prevalent in type 2 diabetic patients attending the diabetic center at Al-Noor Specialist Hospital, Makkah Al-Mukarramah; particularly the mild NP type.

Berberine protects against diabetic retinopathy by inhibiting cell apoptosis via deactivation of the NF‑κB signaling pathway

A number of studies have reported that diabetic retinopathy (DR) is the major cause of blindness. Berberine (BBR) is a bioactive constituent that displays effects on blood glucose; however, the mechanism underlying the role of BBR during the development of DR is not completely understood. In the present study, a rat model of DR was successfully established. The eye tissues were removed and subsequently assessed by hematoxylin and eosin staining and the TUNEL assay. The catalase, malondialdehyde, reactive oxygen species, glutathione and superoxide dismutase contents of the eye tissues were measured. Müller cells were chosen for further in vitro experiments. Cell apoptosis was examined by Annexin V-FITC apoptosis detection and Hoechst staining, and the mitochondrial membrane potential was assessed by JC-1 mitochondrial membrane potential detection. BBR decreased ganglion cell layer, cell apoptosis, reduced diabetic-induced oxidative stress and deactivated the NF-κB signaling pathway in the rat model of DR. High glucose enhanced oxidative stress and induced mitochondria-dependent cell apoptosis in Müller cells by activating the NF-κB signaling pathway. BBR reversed the high glucose-induced effects by decreasing the phosphorylation of IκB, inhibiting NF-κB nuclear translocation and deactivating the NF-κB signaling pathway. The results suggested that BBR protected against DR by inhibiting oxidative stress and cell apoptosis via deactivation of the NF-κB signaling pathway; therefore, suggesting that BBR may serve as a promising therapeutic agent for DR.

Is Insulin Therapy Safe?

BACKGROUND

After 98 years of insulin therapy, issues of safety remain of concern.

AREAS OF UNCERTAINTY

Uncertainty has been expressed variously in regard of arterial cell wall proliferation, promotion of proliferative retinopathy, promotion of tumor growth, and for pregnancy. Immunological issues have been little studied since the advent of highly purified insulins in the 1970s. A specific topic is whether hypoglycemia, severe or otherwise, might promote cardiac thrombotic or dysrhythmic events.

DATA SOURCES

A literature review in these areas is difficult because nearly all clinical trials with insulin refer to adverse events. However, the specific topics aforementioned allow for some informed literature searching supplemented by finger-searching of published articles, notably in connection with the insulin analogues.

THERAPEUTIC UNDERSTANDINGS

Safety data for pregnancy are weak because of power problems, but there are no signals for added maternal or fetal risk. Clinical-outcome trials that assess insulin against other glucose-lowering therapies or with significantly different insulin preparations in different arms are few and are sometimes conducted at modest dosage but fail to suggest promotion of arterial disease. Concern over growth-promoting activity of insulin glargine turned out to be ill-founded when the circulating moiety after injection was noted to have a lower IGF-1:insulin activity than human insulin, and a direct study of retinopathy progression or meta-analysis of malignancy incidence failed to show signals of concern. It does seem that severe hypoglycemia can cause death in some people with type 1 diabetes, although the tissue mechanism is unknown, but reducing severe hypoglycemia in type 2 diabetes does not protect against arterial events. Both symptomatic and severe hypoglycemia can however be reduced by use of more recently marketed insulin analogues, and this improves tolerability if not safety.

CONCLUSIONS

In conclusion, although insulin therapy clearly gives health benefits, the evidence for long-term harm is absent or weak.

Effect of basal insulin supplement therapy on diabetic retinopathy in short-duration type 2 diabetes: A one-year randomized parallel-group trial

BACKGROUND

In this study, we compared the effect on diabetic retinopathy (DR) between oral antidiabetic drugs (OADs) alone and in combination with basal insulin-supported OADs therapy (BOT). [Correction added on 11 November 2019, after first online publication: In Abstract under Background section, "DR" has been corrected into "diabetic retinopathy (DR)".] METHODS: Between January 2015 and January 2018, this study enrolled 290 patients (age 18-65 years) with diabetes duration between 0 and 5 years. Patients were randomly assigned to receive OADs or BOT after 14 days intensive insulin treatment. Examinations were performed at the beginning and end of the study.

RESULTS

Fewer patients developed DR in the BOT than OADs group (8 [6.06%] vs 12 [8.3%], respectively), and all cases of DR were non-proliferative. Blood glucose concentrations were higher in the BOT than OADs group at the 3rd month, but lower in the former at the 6th and 12th month. The rate of reaching target HbA1c ≤7% was lower in the BOT than OADs group at the 3rd month (63.6% vs 72.2%, respectively), similar between the two groups at the 6th month (60.6% vs 66.6%, respectively) and higher in the BOT group at the 12th month (75.0% vs 61.1%, respectively). The SD of fasting blood glucose (FBG), coefficient of variation of FBG, SD of blood glucose (SDBG), and mean amplitude of glycemic excursions were lower in the BOT than OADs group. Changes in the levels of three cytokines (interleukin [IL]-1β, IL-6, and IL-17α) were significantly less in the BOT than OADs group.

CONCLUSIONS

Twelve months of BOT decreased the incidence of DR in short-duration type 2 diabetes by reducing glycemia more effectively, stably, and completely than OADs alone.

OMICs approaches-assisted identification of macrophages-derived MIP-1γ as the therapeutic target of botanical products TNTL in diabetic retinopathy

Background

Inflammatory reaction in the dysfunction of retinal endotheliocytes has been considered to play a vital role in diabetic retinopathy (DR). Anti-inflammatory therapy so far gains poor outcome as DR treatment. This study aims to identify a novel therapeutic target of DR from the OMICs studies of a traditional anti-DR botanical products TNTL.

Methods

Hyperglycemic mice were treated with TNTL. The anti-hyperglycemic effect of TNTL was validated to confirm the biological consistency of the herbal products from batches. Improvement of DR by TNTL was examined by various assays on the retina. Next-generation transcriptome sequencing and cytokine array was used to identify the therapeutic targets. In vitro study was performed to validate the target.

Results

We observed that TNTL at its high doses possessed anti-hyperglycemic effect in murine type I diabetic model, while at its doses without reducing blood glucose, it suppressed DR incidence. TNTL restored the blood-retina barrier integrity, suppressed retinal neovascularization, and attenuated the retinal ganglion cell degeneration. Transcriptomic analysis on the retina tissue of hyperglycemic mice with or without TNTL revealed that the inflammatory retina microenvironment was significantly repressed. TNTL treatment suppressed pro-inflammatory macrophages in the retina, which resulted in the inactivation of endothelial cell migration, restoration of endothelial cell monolayer integrity, and prevention of leakage. Cytokine array analysis suggested that TNTL could significantly inhibit the secretion of MIP1γ from pro-inflammatory macrophages. Prevention of endothelial dysfunction by TNTL may be mediated by the inhibition of MIP1γ/CCR1 axis. More specifically, TNTL suppressed MIP1γ release from pro-inflammatory macrophages, which in turn inhibited the activation of CCR1-associated signaling pathways in endothelial cells.

Conclusion

Our findings demonstrated that TNTL might be an alternative treatment to DR, and the primary source of potential drug candidates against DR targeting MIP1γ/CCR1 axis in the retinal microenvironment.

Retinal images benchmark for the detection of diabetic retinopathy and clinically significant macular edema (CSME)

Diabetes mellitus is an enduring disease related with significant morbidity and mortality. The main pathogenesis behind this disease is its numerous micro- and macrovascular complications. In developing countries, diabetic retinopathy (DR) is one of the major sources of vision impairment in working age population. DR has been classified into two categories: proliferative diabetic retinopathy (PDR) and non-proliferative diabetic retinopathy (NPDR). NPDR is further classified into mild, moderate and severe, while PDR is further classified into early PDR, high risk PDR and advanced diabetic eye disease. DR is a disease caused due to high blood glucose levels which result in vision loss or permanent blindness. High-level advancements in the field of bio-medical image processing have speeded up the automated process of disease diagnoses and analysis. Much research has been conducted and computerized systems have been designed to detect and analyze retinal diseases through image processing. Similarly, a number of algorithms have been designed to detect and grade DR by analyzing different symptoms including microaneurysms, soft exudates, hard exudates, cotton wool spots, fibrotic bands, neovascularization on disc (NVD), neovascularization elsewhere (NVE), hemorrhages and tractional bands. The visual examination of the retina is a vital test to diagnose DR-related complications. However, all the DR computer-aided diagnostic systems require a standard dataset for the estimation of their efficiency, performance and accuracy. This research presents a benchmark for the evaluation of computer-based DR diagnostic systems. The existing DR benchmarks are small in size and do not cover all the DR stages and categories. The dataset contains 1445 high-quality fundus photographs of retinal images, acquired over 2 years from the records of the patients who presented to the Department of Ophthalmology, Holy Family Hospital, Rawalpindi. This benchmark provides an evaluation platform for medical image analysis researchers. Furthermore, it provides evaluation data for all the stages of DR.

Development of diabetic retinopathy after cataract surgery

This study explored whether cataract surgery precipitates diabetic retinopathy (DR) development in diabetic patients without previous DR. Patients with the diagnosis of type II diabetes but without DR were selected from the Longitudinal Health Insurance Database 2000. Patients who received cataract surgery between January 1, 2000, and December 31, 2010, were included in the case group, and the control group was matched to the case group by age, sex, and index year. The postoperative incidence rates of nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), and diabetic macular edema (DME) were the main outcomes studied and were adjusted by age, sex, comorbidities, and statin, fibrate, angiotensin-converting-enzyme inhibitor (ACEI), oral hypoglycemic agents (OHA), and insulin use. In our cohort, patients who had dyslipidemia and used statins were more likely to undergo cataract surgery. Among diabetic patients without previous DR, patients receiving cataract surgery had a higher risk of NDPR development (adjusted hazard ratio = 1.48, 95% confidence interval = 1.15–1.91). No statistical difference was observed in PDR or DME development between operative and nonoperative groups. In additional stratified analyses, female sex, older age, comorbidities, surgery within 5 years, statin, ACEI, OHA, and insulin use increased the risk of NPDR development. In an adjusted Cox regression model, cataract surgery, OHA and insulin use were found to be risk factors for NPDR development. Cataract surgery with complications increased post-operative risks for NPDR were even higher, and the significant influence from cataract surgery persisted 5 years after surgery.

Prevalence, risk factors and burden of diabetic retinopathy in China: a systematic review and meta-analysis

Background

Diabetic retinopathy (DR), the primary retinal vascular complication of diabetes mellitus (DM), is a leading cause of vision impairment and blindness in working-age population globally. Despite mounting concerns about the emergence of DM as a major public health problem in the largest developing country, China, much remains to be understood about the epidemiology of DR. We aimed to investigate the prevalence of and risk factors for DR, and estimate the burden of DR in China in 2010.

Methods

China National Knowledge Infrastructure (CNKI), Wanfang, Chinese Biomedicine Literature Database (CBM-SinoMed), PubMed, Embase and Medline were searched for studies that reported the prevalence of and risk factors for DR in Chinese population between 1990 and 2017. A random-effects meta-analysis model was adopted to pool the overall prevalence of DR. Variations in the prevalence of DR in different age groups, DM duration groups and settings were assessed by subgroup meta-analysis and meta-regression. Odds ratios (ORs) of major risk factors were pooled using random-effects meta-analysis. The number of people with DR in 2010 was estimated by multiplying the age-specific prevalence of DR in people with DM with the corresponding number of people with DM in China. Finally, the national number of people with DR was distributed into six geographic regions using a risk factor-based model.

Results

A total of 31 studies provided information on the prevalence of DR and 21 explored potential risk factors for DR. The pooled prevalence of any DR, nonproliferative DR (NPDR) and proliferative DR (PDR) was 1.14% (95% CI = 0.80-1.52), 0.90% (95% CI = 0.56-1.31) and 0.07% (95% CI = 0.02-0.14) in general population; In people with DM, the pooled prevalence rates were 18.45% (95% CI = 14.77-22.43), 15.06% (95% CI = 11.59-18.88) and 0.99% (95% CI = 0.40-1.80) for any DR, NPDR and PDR, respectively. The prevalence of any DR in DM patients peaked between 60 and 69 years of age, and increased steeply with the duration of DM. DM patients residing in rural China were at a higher risk to have DR than those in urban areas. In addition, insulin treatment, elevated FBG level and higher HbA1c concentration were confirmed to be associated with a higher prevalence of DR in people with DM, with meta-ORs of 1.99 (95% CI = 1.34-2.95), 1.33 (95% CI = 1.12-1.59) and 1.15 (95% CI = 1.09-1.20) respectively. In 2010, a total of 13.16 million (95% CI = 8.95-18.00) Chinese aged 45 years and above were living with DR, among whom the most were in South Central China and the least were in Northwest China.

Conclusions

DR has become a serious public health problem in China. Optimal screening of and interventions on DR should be implemented. Improved epidemiological studies on DR are still required.

Mechanism of worsening diabetic retinopathy with rapid lowering of blood glucose: the synergistic hypothesis

Insulin treatment has been associated with a paradoxical worsening of diabetes retinopathy since many years in European cohorts. Recently, this issue has been stressed by some studies conducted in other parts of the world. However, the mechanism underlying such evolution is not well understood. An osmotic theory has been evocated but failed to explain the clinical features of the disease. Considering recent findings from basic and clinical research, we discuss the possibility of a synergistic hypothesis based on the simultaneous action of insulin and vascular endothelial growth factor on eye blood vessels. We postulate that exogenous insulin could act synergistically with the vascular endothelial growth factor expressed by ischemic retina so as to trigger vascular proliferation and the worsening of diabetes retinopathy.

3D endothelial cell spheroid/human vitreous humor assay for the characterization of anti-angiogenic inhibitors for the treatment of proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) represents a main cause of acquired blindness. Despite the recognition of the key role exerted by vascular endothelial growth factor (VEGF) in the pathogenesis of PDR, limitations to anti-VEGF therapies do exist. Thus, rapid and cost-effective angiogenesis assays are crucial for the screening of anti-angiogenic drug candidates for PDR therapy. In this context, evaluation of the angiogenic potential of PDR vitreous fluid may represent a valuable tool for preclinical assessment of angiostatic molecules. Here, vitreous fluid obtained from PDR patients after pars plana vitrectomy was used as a pro-angiogenic stimulus in a 3D endothelial cell spheroid/human vitreous assay. The results show that PDR vitreous is able to stimulate the sprouting of fibrin-embedded HUVEC spheroids in a time- and dose-dependent manner. A remarkable variability was observed among 40 individual vitreous fluid samples in terms of sprouting-inducing activity that was related, at least in part, to defined clinical features of the PDR patient. This activity was hampered by various extracellular and intracellular signaling pathway inhibitors, including the VEGF antagonist ranibizumab. When tested on 20 individual vitreous fluid samples, the inhibitory activity of ranibizumab ranged between 0 and 100% of the activity measured in the absence of the drug, reflecting a variable contribution of angiogenic mediators distinct from VEGF. In conclusion, the 3D endothelial cell spheroid/human vitreous assay represents a rapid and cost-effective experimental procedure suitable for the evaluation of the anti-angiogenic activity of novel extracellular and intracellular drug candidates, with possible implications for the therapy of PDR.

Plasma miR-21 expression: an indicator for the severity of Type 2 diabetes with diabetic retinopathy

To investigate the roles of plasma miR-21 in the pathogenic process of Type 2 diabetes (T2D) with diabetic retinopathy (DR). T2D patients included patients without DR (NDR) group, patients with non-proliferative/background DR (BDR) group and patients with proliferative DR (PDR) group. Healthy individuals served as control group. Fasting plasma glucose (FPG), glycosylated haemoglobin (HbA1c), triacylglycerol (TG), total cholesterol (TC), urine creatinine (Cr), fasting blood glucose (FBG), blood urea nitrogen (BUN), low-density lipoprotein cholesterol (LDL-C), fasting insulin (FINS) and plasma miR-21 expression were measured. Quantitative real-time PCR (qRT-PCR) was applied to detect miR-21 expression. Pearson analysis was used to conduct correlation analysis and receiver operating characteristic (ROC) curve was used to analyse the diagnostic value of miR-21 in T2D with DR. Compared with the control group, FBG and HbA1c increased in the NDR group; compared with the control and NDR groups, disease course, HbA1c, FPG levels and homoeostasis model assessment of insulin resistance (HOMA-IR) were increased in the BDR and PDR groups; and compared with the BDR group, disease course, HbA1c and FPG levels were higher in the PDR group. miR-21 expression was higher in the BDR group than the control group, and higher in the PDR group than the BDR group. miR-21 expression was positively related with disease course, HbA1C, FPG and HOMA-IR, and had diagnostic value for T2D with DR and PDR. The plasma miR-21 expression was increased in the development of T2D with DR and can be used as an indicator for the severity of T2D with DR.

Association of insulin treatment versus oral hypoglycaemic agents with diabetic retinopathy and its severity in type 2 diabetes patients in Cameroon, sub-Saharan Africa

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease associated with multiple macro and microvascular complications, diabetic retinopathy (DR) being the commonest one. Recent literature has reported an increased risk of DR with insulin use.

METHODS

We carried out a cross-sectional study at the Ophthalmology Department of the Douala General Hospital (DGH) during a 2-year period to explore the association between insulin treatment and both DR and its severity as compared with oral hypoglycemic agents (OHAs) in Cameroonian T2DM patients aged ≥35 years, and who were all screened for DR through eye examination including exhaustive retinal evaluation.

RESULTS

In total, medical files of 134 T2DM patients were analyzed. The frequency of DR was 54.1% among patients on OHA and 73.9% among those on insulin treatment, giving an overall frequency of 57.5%. There were significantly more OHA treated patients than insulin treated patients (82.8% vs. 17.2%, P<0.001). As expected, both the OHA and insulin groups were comparable by age, sex, duration of diabetes, past history of hypertension, alcohol misuse, and current tobacco smoking. DR was almost significantly more frequent in T2DM patients under insulin regimen than in patients under OHA [73.9% vs. 54.1%; odds ratio (OR) 2.4; 95% confidence interval (CI), 0.9-6.6; P=0.06]. Proliferative diabetic retinopathy (PDR) was significantly more observed in insulin treated patients than in OHA treated patients (34.8% vs. 15.3%; OR 2.95; 95% CI, 1.1-8; P=0.035). Irrespective of staging, the frequency of diabetic macular edema (DME) was significantly higher in the insulin group than in the OHA group (43.5% vs. 19.8%; OR 3.1; 95% CI, 1.2-8; P=0.019).

CONCLUSIONS

Compared with OHA, insulin therapy may be associated with DR, DR severity and DME in these T2DM sub-Saharan African patients.

Changes in Choroidal Thickness and Corneal Parameters in Diabetic Eyes

Purpose

To evaluate the effect of diabetes mellitus (DM) on central corneal thickness (CCT), corneal endothelial parameters (endothelial cell density [ECD], average size [AVE], hexagonality [A6], polymegathism [SD]), and subfoveal choroidal thickness (SFCT), and to determine whether these parameters depend on the duration of DM and hemoglobin A1c (HbA1c) level.

Methods

A total of 62 patients with type 2 DM and 65 healthy subjects were examined using a noncontact specular microscope, A-scan ultrasound, and spectral-domain optical coherence tomography. The study parameters included medical history, age, eye axial length, CCT, ECD, AVE, A6, SD, and SFCT. The duration of DM and HbA1c level of the 2 latest tests were noted.

Results

The SFCT (258.0 ± 74.4 µm) and ECD (2721.8 ± 264.1 cells/mm2) were significantly lower, and the CCT (566.7 ± 35.7 µm) higher, in diabetic patients than in the control group (313.1 ± 88.5 µm, 2967.3 ± 220.6 cells/mm2, 550.0 ± 56.4 µm, respectively) (p<0.05). There were no differences in age, sex, or axial length between the diabetic and control groups (p>0.05). Diabetic retinopathy and macular edema did not influence SFCT significantly (p>0.05). No differences in endothelial parameters between groups and no correlations among HbA1c, duration of DM, and any of the examined parameters were found (p>0.05).

Conclusions

Diabetic patients have thicker corneas, lower ECD, and thinner subfoveal choroid than healthy subjects.

Relationship between homocysteine level and diabetic retinopathy: a systematic review and meta-analysis

Background

The relationship between homocysteine (Hcy) and diabetic retinopathy (DR) remains unclear to date. Therefore, a systematic review and meta-analysis was performed on the relationship between Hcy level and DR.

Methods

Studies were identified by searching PubMed, Embase, and Web of Science databases until 5 May, 2014.

Results

A total of 31 studies involving 6,394 participants were included in the meta-analysis. After pooling the data from each included study, the blood Hcy concentration in the DR group was observed to be higher than that in the control group [WMD = 2.55; 95% confidence interval (CI), 1.70–3.40], and diabetes mellitus (DM) patients with hyperhomocysteinemia were at a risk for DR [odds ratio (OR) = 1.93; 95% CI, 1.46–2.53]. Considering the different DM types, hyperhomocysteinemia in T1DM (OR = 1.83, 95% CI, 1.28–2.62) was associated with DR rather than in T2DM (OR = 1.59, 95% CI, 0.72–3.51). Considerable statistical heterogeneity in the overall summary estimates was partly explained by the geographical differences.

Conclusions

Results from this current meta-analysis indicate that hyperhomocysteinemia is a risk factor for DR, especially proliferative DR. Differences between geographical regions were observed in the relationship between hyperhomocysteinemia with T1DM risk. Given the heterogeneous results, the relationship between high Hcy and DR needs further investigation.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_167