Microalbuminuria and low hemoglobin as risk factors for the occurrence and increasing severity of diabetic retinopathy

Association of serum lipid profile and other systemic risk factors with retinal hard exudates in diabetic retinopathy

PURPOSE

Diabetic macular edema is one of the leading causes of vision loss across the world. Hard exudates at the macula can lead to structural abnormalities in the retina leading to irreversible vision loss. Systemic dyslipidemia and other modifiable risk factors when identified and treated early may help prevent substantial vision loss. The purpose of this study was to study the association between serum lipid levels and other systemic risk factors like hemoglobin, HbA1c, and serum creatinine with hard exudates and macular edema in patients with diabetic retinopathy.

METHODS

It is a prospective cross-sectional study conducted in a tertiary health care center in South India. 96 patients having diabetic retinopathy with hard exudates were included. Modified Airlie house classification was used to grade the hard exudates. Blood investigations including serum lipid profile, hemoglobin, HbA1c, and serum creatinine were carried out. Central subfield macular thickness was measured using optical coherence tomography.

RESULTS

96 patients of type II DM with diabetic retinopathy were divided into three groups of hard exudates. A statistically significant correlation was observed between the severity of hard exudates and total cholesterol (p = 0.00), triglycerides (p = 0.00), LDL (p = 0.00), and VLDL (p = 0.00). HbA1c levels showed a statistically significant correlation with the severity of hard exudates (p = 0.09), no significant correlation was noted between hard exudates and hemoglobin levels (p = 0.27) and with serum creatinine (p = 0.612). A statistically significant association between CSMT and hard exudates (p = 0.00) was noted.

CONCLUSION

In our study, we concluded that the severity of hard exudates is significantly associated with increasing levels of serum total cholesterol, triglycerides, LDL, VLDL, and HbA1c levels in type II DM patients presenting with diabetic retinopathy. The increasing duration of diabetes is significantly associated with increasing severity of hard exudates. Central subfield macular thickness increases with increasing severity of hard exudates in diabetic retinopathy.

Development and validation of a simple and practical model for early detection of diabetic macular edema in patients with type 2 diabetes mellitus using easily accessible systemic variables

OBJECTIVE

Diabetic macular edema (DME) is the leading cause of visual impairment in patients with diabetes mellitus (DM). The goal of early detection has not yet achieved due to a lack of fast and convenient methods. Therefore, we aim to develop and validate a prediction model to identify DME in patients with type 2 diabetes mellitus (T2DM) using easily accessible systemic variables, which can be applied to an ophthalmologist-independent scenario.

METHODS

In this four-center, observational study, a total of 1994 T2DM patients who underwent routine diabetic retinopathy screening were enrolled, and their information on ophthalmic and systemic conditions was collected. Forward stepwise multivariable logistic regression was performed to identify risk factors of DME. Machine learning and MLR (multivariable logistic regression) were both used to establish prediction models. The prediction models were trained with 1300 patients and prospectively validated with 104 patients from Guangdong Provincial People's Hospital (GDPH). A total of 175 patients from Zhujiang Hospital (ZJH), 115 patients from the First Affiliated Hospital of Kunming Medical University (FAHKMU), and 100 patients from People's Hospital of JiangMen (PHJM) were used as external validation sets. Area under the receiver operating characteristic curve (AUC), accuracy (ACC), sensitivity, and specificity were used to evaluate the performance in DME prediction.

RESULTS

The risk of DME was significantly associated with duration of DM, diastolic blood pressure, hematocrit, glycosylated hemoglobin, and urine albumin-to-creatinine ratio stage. The MLR model using these five risk factors was selected as the final prediction model due to its better performance than the machine learning models using all variables. The AUC, ACC, sensitivity, and specificity were 0.80, 0.69, 0.80, and 0.67 in the internal validation, and 0.82, 0.54, 1.00, and 0.48 in prospective validation, respectively. In external validation, the AUC, ACC, sensitivity and specificity were 0.84, 0.68, 0.90 and 0.60 in ZJH, 0.89, 0.77, 1.00 and 0.72 in FAHKMU, and 0.80, 0.67, 0.75, and 0.65 in PHJM, respectively.

CONCLUSION

The MLR model is a simple, rapid, and reliable tool for early detection of DME in individuals with T2DM without the needs of specialized ophthalmologic examinations.

Prevalence and associated factors of proliferative diabetic retinopathy among adult diabetic patients in Northwest Ethiopia, 2023: A cross-sectional multicenter study

BACKGROUND

Proliferative diabetic retinopathy is one of the advanced complications of diabetic retinopathy. If left untreated, almost all eyes could lose a significant portion of their vision within four months. There is limited evidence regarding the magnitude of proliferative diabetic retinopathy and associated factors in the study setting and also in Ethiopia.

PURPOSE

To determine the magnitude and associated factors of proliferative diabetic retinopathy among adult diabetic patients attending Specialized Comprehensive Hospital-Diabetic Care Clinics in Northwest Ethiopia, 2023.

METHODS

A multicenter, hospital-based, cross-sectional study was conducted on 1219 adult diabetic patients selected by systematic random sampling technique. Data were collected through an in-person interview and physical examination. The Statistical Package for Social Science Version 20 was used to analyze the data. Logistic regression methods were used to test the association between predisposing factors and proliferative diabetic retinopathy. The adjusted odds ratio with a 95% confidence interval was used to determine the strength of association.

RESULTS

The prevalence of proliferative diabetic retinopathy was 3.1% (95% CI: 2.10%-4.10%). Hypertension (AOR = 4.35 (95% CI: 1.87-10.12)), peripheral neuropathy (AOR = 3.87 (95% CI: 1.57-9.54)), nephropathy (AOR = 2.58 (95% CI: 1.13-5.87)), ≥10 years duration of diabetes mellitus (AOR = 5.30 (95% CI: 2.32-12.14)), insulin use (AOR = 3.07 (95% CI: 1.08-8.68)), and poor adherence to diabetes mellitus medications (AOR = 3.77 (95% CI: 1.64-8.64)) were confirmed to have statistically significant association with proliferative diabetic retinopathy.

CONCLUSION

The prevalence of proliferative diabetic retinopathy among adult diabetic patients in the diabetes clinic was higher than the global study. Hypertension, peripheral neuropathy, nephropathy, ≥10 year's duration of diabetic mellitus, insulin use and poor adherence to diabetes mellitus medications were among the factors significantly associated with proliferative diabetic retinopathy.

Correlation of hemoglobin levels with diabetic retinopathy in US adults aged ≥40 years: the NHANES 2005-2008

Purpose

The aim of this study was to explore the connection between hemoglobin levels and diabetic retinopathy (DR).

Methods

Cross-sectional research used data from the National Health and Nutrition Examination Survey (NHANES) 2005-2008. A multiple logistic regression analysis was performed to investigate the association between DR and hemoglobin levels. Additionally, generalized additivity models and smoothed curve fitting were carried out.

Results

After adjusting for several covariates, there was a negative association between hemoglobin levels and DR in the study, which included 837 participants. The negative association between hemoglobin levels and DR was present in men and women, the obese (BMI > 30), and 60- to 69-year-olds in subgroup analyses stratified by sex, BMI, and age. The association between hemoglobin levels and DR in the normal weight group (BMI < 25) displayed an inverted U-shaped curve with an inflection point of 13.7 (g/dL).

Conclusion

In conclusion, our research reveals that high hemoglobin levels are related to a decreased risk of DR. Ascertaining the hemoglobin levels ought to be regarded as an integral facet of the monitoring regimen for patients with diabetic complications and that the risk of DR is reduced through the detection and management of hemoglobin levels.

Association of renal function with diabetic retinopathy and macular oedema among Chinese patients with type 2 diabetes mellitus

OBJECTIVES

To investigate the associations of renal function with diabetic retinopathy (DR) and diabetic macular oedema (DMO) in diabetic patients.

METHODS

A total of 1877 diabetic participants aged 30 to 80 years were consecutively recruited between October 2017 and April 2019. The presence of DR, vision-threatening DR (VTDR) and DMO were graded using seven-field fundus photographs. Renal function was defined as normal, mildly impaired or indicative of chronic kidney disease (CKD) based on different estimated glomerular filtration rates (GFR).

RESULTS

In the multivariable logistic regression model, decreased GFR was associated with the presence of any DR only in the presence of microalbuminuria (OR = 2.40 for mildly impaired and 3.37 for CKD, all P < 0.05), while an impaired GFR was an independent risk factor for VTDR regardless of microalbuminuria status (all P < 0.05). The risks of any DR (OR = 1.74 for quartile 2 and 3.09 for quartile 4) and VTDR (OR = 3.27 for quartile 2 and 6.41 for quartile 4) increased gradually along with microalbuminuria quartile (all P < 0.05). CKD (OR = 3.07, P = 0.012) and high microalbuminuria (OR = 3.22 for quartile 3 and 5.25 for quartile 4, all P < 0.05) were independent DMO risk factors.

CONCLUSIONS AND RELEVANCE

There is a strong association between GFR and VTDR, whereas the association between GFR and any DR was significant only under the premise of microalbuminuria. High microalbuminuria and CKD were significantly associated with DMO.

Prevalence of anemia in diabetes mellitus in South Asia: A systematic review and meta-analysis

OBJECTIVE

Anemia and Diabetes Mellitus (DM) are amongst major clinical and public health challenges in South Asia that influence the progression of chronic health problems in this population. Despite a growing body of research on these problems, there is a lack synthesized evidence on the burden of anemia among people with DM in this region. This meta-analytic review was conducted to estimate the prevalence of anemia among people with DM in South Asia.

METHODS

A systematic search of the literature was conducted in five primary databases and additional sources up to July 29, 2022, that reported the prevalence of anemia among DM patients in any of the eight South Asian countries. Observational studies that met pre-determined eligibility criteria according to the protocol registered in PROSPERO (CRD42022348433) were included in this meta-analysis. Random effect models were used to estimate pooled prevalence.

RESULTS

Of the 40 eligible studies, 38 underwent meta-analysis representing 14,194 participants with DM. The pooled prevalence of anemia was 45% (95% CI: 37.0-54.0, I2 = 99.28%, p = 0.00) among diabetic people in South Asia. In sub-group analysis, the pooled prevalence of anemia was higher in females (48%, 95% CI: 37.0-60.0, I2 = 98.86%, p = 0.00) compared to males (39%, 95% CI: 29.0-48.0, I2 = 98.18%, p = 0.00). Diabetic patients with older age (≥ 50 years) reported higher pooled estimates of anemia (48%, 95% CI: 38.0-58.0, I2 = 99.07%) than younger age group (< 50 years) (34%, 95% CI: 21.0-47.0, I2 = 98.83%). In addition, we found variation in pooled prevalence estimates of anemia considering the type of DM, such as type 1 reported 2% (95% CI: 0.00-4.00), type-2 reported 48% (95% CI: 40.0-56.0, I2 = 98.94%), and Gestational diabetes mellitus (GDM) reported 6% (95% CI: 3.00-12.0).

CONCLUSION

High pooled estimates of anemia among diabetic patients in South Asia, including publication bias, warrants further clinical and public health research following standard research methods to understand the more context-specific epidemiological insights and evidence.

Retinal microvascular changes in diabetic patients with diabetic nephropathy

BACKGROUND

To explore the characteristics of retina microvascular changes in patients with diabetic nephropathy (DN) and its risk factors.

METHODS

Retrospective, observational study. 145 patients with type 2 diabetic mellitus (DM) and DN were included in the study. Demographic and clinical parameters were obtained from medical records. Presence of diabetic retinopathy (DR), hard exudates (HEs) and diabetic macular edema (DME) were evaluated according to the color fundus images, optical coherence tomography (OCT) and fluorescence angiography (FFA).

RESULTS

DR accounted for 61.4% in type 2 DM patients with DN, of which proliferative diabetic retinopathy (PDR) accounted for 23.6% and sight threatening DR accounted for 35.7%. DR group had significantly higher levels of low-density lipoprotein cholesterol (LDL-C) (p = 0.004), HbA1c (P = 0.037), Urine albumin creatine ratio (ACR) (p < 0.001) and lower level of estimated glomerular filtration rate (eGFR) (P = 0.013). Logistic regression analysis showed DR was significantly associated with ACR stage (p = 0.011). Subjects with ACR stage3 had higher incidence of DR compared with subjects with ACR stage1 (OR = 24.15, 95%CI: 2.06-282.95). 138 eyes of 138 patients were analyzed for HEs and DME, of which 23.2% had HEs in posterior pole and 9.4% had DME. Visual acuity was worse in HEs group than in non-HEs group. There was significant difference in the LDL-C cholesterol level, total cholesterol (CHOL) level and ACR between HEs group and non-HEs group.

CONCLUSIONS

A relatively higher prevalence of DR was found in type 2 DM patients with DN. ACR stage could be recognized as a risk factor for DR in DN patients. Patients with DN needs ophthalmic examination more timely and more frequently.

Gene Biomarkers Related to Th17 Cells in Macular Edema of Diabetic Retinopathy: Cutting-Edge Comprehensive Bioinformatics Analysis and In Vivo Validation

Background

Previous studies have shown that T-helper 17 (Th17) cell-related cytokines are significantly increased in the vitreous of proliferative diabetic retinopathy (PDR), suggesting that Th17 cells play an important role in the inflammatory response of diabetic retinopathy (DR), but its cell infiltration and gene correlation in the retina of DR, especially in diabetic macular edema (DME), have not been studied.

Methods

The dataset GSE160306 was downloaded from the Gene Expression Omnibus (GEO) database, which contains 9 NPDR samples and 10 DME samples. ImmuCellAI algorithm was used to estimate the abundance of Th17 cells in 24 kinds of infiltrating immune cells. The differentially expressed Th17 related genes (DETh17RGs) between NPDR and DME were documented by difference analysis and correlation analysis. Through aggregate analyses such as gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analysis, a protein-protein interaction (PPI) network was constructed to analyze the potential function of DETh17RGs. CytoHubba plug-in algorithm, Lasso regression analysis and support vector machine recursive feature elimination (SVM-RFE) were implemented to comprehensively identify Hub DETh17RGs. The expression archetypes of Hub DETh17RGs were further verified in several other independent datasets related to DR. The Th17RG score was defined as the genetic characterization of six Hub DETh17RGs using the GSVA sample score method, which was used to distinguish early and advanced diabetic nephropathy (DN) as well as normal and diabetic nephropathy. Finally, real-time quantitative PCR (qPCR) was implemented to verify the transcription levels of Hub DETh17RGs in the STZ-induced DR model mice (C57BL/6J).

Results

238 DETh17RGs were identified, of which 212 genes were positively correlated while only 26 genes were negatively correlated. Six genes (CD44, CDC42, TIMP1, BMP7, RHOC, FLT1) were identified as Hub DETh17RGs. Because DR and DN have a strong correlation in clinical practice, the verification of multiple independent datasets related to DR and DN proved that Hub DETh17RGs can not only distinguish PDR patients from normal people, but also distinguish DN patients from normal people. It can also identify the initial and advanced stages of the two diseases (NPDR vs DME, Early DN vs Advanced DN). Except for CDC42 and TIMP1, the qPCR transcription levels and trends of other Hub DETh17RGs in STZ-induced DR model mice were consistent with the human transcriptome level in this study.

Conclusion

This study will improve our understanding of Th17 cell-related molecular mechanisms in the progression of DME. At the same time, it also provides an updated basis for the molecular mechanism of Th17 cell crosstalk in the eye and kidney in diabetes.

Recently updated global diabetic retinopathy screening guidelines: commonalities, differences, and future possibilities

Diabetic retinopathy (DR) is a global health burden. Screening for sight-threatening DR (STDR) is the first cost-effective step to decrease this burden. We analyzed the similarities and variations between the recent country-specific and the International Council of Ophthalmology (ICO) DR guideline to identify gaps and suggest possible solutions for future universal screening. We selected six representative national DR guidelines, one from each World Health Organization region, including Canada (North America), England (Europe), India (South- East Asia), Kenya (Africa), New Zealand (Western Pacific), and American Academy of Ophthalmology Preferred Practice Pattern (used in Latin America and East Mediterranean). We weighed the newer camera and artificial intelligence (AI) technology against the traditional screening methodologies. All guidelines agree that screening for DR and STDR in people with diabetes is currently led by an ophthalmologist; few engage non-ophthalmologists. Significant variations exist in the screening location and referral timelines. Screening with digital fundus photography has largely replaced traditional slit-lamp examination and ophthalmoscopy. The use of mydriatic digital 2-or 4-field fundus photography is the current norm; there is increasing interest in using non-mydriatic fundus cameras. The use of automated DR grading and tele-screening is currently sparse. Country-specific guidelines are necessary to align with national priorities and human resources. International guidelines such as the ICO DR guidelines remain useful in countries where no guidelines exist. Validation studies on AI and tele-screening call for urgent policy decisions to integrate DR screening into universal health coverage to reduce this global public health burden.

Prevalence of and Factors Associated with Diabetic Retinopathy in Patients with Diabetes Mellitus at Siriraj Hospital - Thailand's Largest National Tertiary Referral Center

PURPOSE

We aimed to determine the prevalence of and factors associated with diabetic retinopathy (DR) in patients with diabetes mellitus (DM) and to evaluate the relationship between significant factors and severity of DR.

PATIENTS AND METHODS

A retrospective cross-sectional study of 1130 diabetic patients (mean age: 60 years, 62.7% female, 91% type 2 diabetes) was conducted in the diabetes clinic of Siriraj Hospital (Bangkok, Thailand) during January 2012 to June 2015. DR was graded as absent, mild, moderate, or severe non-proliferative DR, or proliferative DR. Multivariate logistic regression analysis was used to identify independent risk factors for DR in DM patients.

RESULTS

The overall prevalence of DR was 34.78%. Multivariate analysis revealed duration of diabetes, glycated hemoglobin level (HbA_1c), presence of albuminuria, and abnormal protective sensation to be independent risk factors for DR. The prevalence of DR increased with longer duration of diabetes (p < 0.001), deterioration of glucose control (p = 0.006 for HbA_1c), presence of significant albuminuria (p = 0.010), and loss of protective sensation (p = 0.001).

CONCLUSION

In this study, one-third of DM were found to have DR. The independent predictors of DR were duration of diabetes, HbA_1c level, presence of significant albuminuria, and impaired protective sensation. Heightened awareness of these risk factors will decrease the prevalence and severity of DR, and will improve early diagnosis and treatment of DR.

Is primary open-angle glaucoma a risk factor for diabetic retinopathy?

PURPOSE

To compare the prevalences of diabetic retinopathy in diabetes mellitus patients, with and without primary open-angle glaucoma, with a view to determine if glaucoma is a risk factor for the development of diabetic retinopathy.

METHODS

Cross-sectional, comparative study consisting of 86 diabetic patients with glaucoma matched with 86 diabetic patients without glaucoma. The two groups were matched by age, sex and duration of diabetes mellitus. Demographic data were obtained via patient medical records and self-administered questionnaires. Participants underwent a standardized examination protocol including blood pressure measurement and ocular examination. Main outcome measure was the presence of diabetic retinopathy.

RESULTS

Two hundred and ninety-two eyes (144 glaucomatous eyes and 148 non-glaucomatous eyes) of 172 participants with diabetes mellitus were assessed. The prevalence of diabetic retinopathy among 86 participants with glaucoma comorbidity was 23.6%, while the prevalence among 86 non-glaucomatous participants was 33.8% (p = 0.06). After the regression analysis, controlling for systemic and ocular risk factors for diabetic retinopathy, the odds of developing diabetic retinopathy were significantly higher in the glaucomatous eyes compared with eyes without glaucoma (OR: 2.75; p = 0.03; 95% CI: 1.10-6.87).

CONCLUSION

This study demonstrated that glaucomatous diabetic eyes were almost three times more likely to develop diabetic retinopathy compared to non-glaucomatous diabetic eyes. Prospective studies may be required to establish a risk-cause relationship. Ocular perfusion pressure control should be considered in patients with diabetes mellitus and glaucoma.

Nomogram-Based Prediction of the Risk of Diabetic Retinopathy: A Retrospective Study

OBJECTIVES

This study is aimed at developing a risk nomogram of diabetic retinopathy (DR) in a Chinese population with type 2 diabetes mellitus (T2DM).

METHODS

A questionnaire survey, biochemical indicator examination, and physical examination were performed on 4170 T2DM patients, and the collected data were used to evaluate the DR risk in T2DM patients. By operating R software, firstly, the least absolute shrinkage and selection operator (LASSO) regression analysis was used to optimize variable selection by running cyclic coordinate descent with 10 times K cross-validation. Secondly, multivariable logistic regression analysis was applied to build a predicting model introducing the predictors selected from the LASSO regression analysis. The nomogram was developed based on the selected variables visually. Thirdly, calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis were used to validate the model, and further assessment was running by external validation.

RESULTS

Seven predictors were selected by LASSO from 19 variables, including age, course of disease, postprandial blood glucose (PBG), glycosylated haemoglobin A1c (HbA1c), uric creatinine (UCR), urinary microalbumin (UMA), and systolic blood pressure (SBP). The model built by these 7 predictors displayed medium prediction ability with the area under the ROC curve of 0.700 in the training set and 0.715 in the validation set. The decision curve analysis curve showed that the nomogram could be applied clinically if the risk threshold is between 21% and 57% and 21%-51% in external validation.

CONCLUSION

Introducing age, course of disease, PBG, HbA1c, UCR, UMA, and SBP, the risk nomogram is useful for prediction of DR risk in T2DM individuals.

Natural history of diabetic macular edema and factors predicting outcomes in sham-treated patients (MEAD study)

PURPOSE

To describe the natural history of diabetic macular edema (DME) with respect to best-corrected visual acuity (BCVA) and central retinal thickness (CRT) outcomes and to identify baseline patient characteristics and systemic factors associated with improvement or worsening of outcomes in sham-treated patients.

METHODS

The study population was sham-treated patients (n = 350) in the 3-year MEAD registration study of dexamethasone intravitreal implant for treatment of DME. Patients had center-involved DME and received sham intravitreal injections in the study eye at ≥ 6-month intervals. Potential prognostic factors for outcomes were evaluated using multiple linear regression analysis.

RESULTS

Visual and anatomic outcomes were poorer in patients who left the study early (n = 198) than in study completers (n = 152). Mean change in BCVA from baseline at the last visit with available data was + 0.9 letters; 37.5% of patients had no change in BCVA, 23.2% had gained > 10 letters, and 16.0% had lost > 10 letters. Older age and baseline diabetic retinopathy score > 6 were associated with worse BCVA outcomes; thicker baseline CRT and larger number of hypertension medications used were associated with larger reductions in CRT during the study.

CONCLUSIONS

BCVA and CRT outcomes were variable in this population of DME patients with generally good glycemic control. In DME patients without active treatment, older age and baseline diabetic retinopathy score > 6 were associated with less improvement in BCVA; thicker baseline CRT and a larger number of antihypertensive medications used predicted better improvement in CRT.

TRIAL REGISTRATION

The MEAD study trials are registered at ClinicalTrials.gov with the identifiers NCT00168337 and NCT00168389.

Association of urinary albumin excretion with central foveal thickness and intravitreal conbercept treatment frequency in patients with diabetic macular edema

AIM

To investigate the effect of albuminuria on diabetic macular edema (DME) and the possible association between baseline urinary albumin excretion (UAE) and intravitreal conbercept (IVC) treatment frequency in DME patients.

METHODS

In this hospital-based retrospective study, a total of 350 in-patients with type 2 diabetes mellitus were recruited and their clinical records were reviewed. Thereafter, 52 patients identified with severe non-proliferative diabetic retinopathy (NPDR) combined with albuminuria were divided into the microalbuminuria (UAE 30-300 mg/24h) and macroalbuminuria (UAE>300 mg/24h) groups, which were compared and analyzed by both independent sample t-test and Chi-square test. Correlations between the systemic variables and the central foveal thickness (CFT) were evaluated using Spearman's correlation and linear regression analyses. Of the 52 patients with center-involved DME, 43 received an initial combined injection of conbercept (0.5 mg/0.05 mL) and triamcinolone acetonide (1 mg/0.05 mL), followed by an IVC injection, as needed. The relationship between baseline UAE and number of IVC injections during the first year of treatment was analyzed using Spearman's partial correlation.

RESULTS

Of 350 patients, a higher incidence of DME was observed in severe non-proliferative retinopathy (NPDR) patients than that observed in other groups. By dividing the 52 patients with severe NPDR into the micro- and macro-albuminuria subgroups, significant differences in CFT, systolic blood pressure, total cholesterol and serum creatinine levels, and UAE were revealed. Furthermore, a positive liner correlation between the UAE and CFT was found. Finally, the partial correlation coefficient adjusted for either the CFT or UAE indicated that both parameters directly correlated with the number of IVC injections administered during the 12mo of follow-up.

CONCLUSION

Generally, macular edema occurred in patients with severe NPDR, for whom the UAE is an independent risk predictor of DME. The baseline UAE and CFT predicted the treatment frequency of IVC injections administered in the first year for eyes with DME.

High hemoglobin levels are associated with decreased risk of diabetic retinopathy in Korean type 2 diabetes

Anemia is an independent risk factor for the development of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (DM). Hemoglobin levels may also be associated with DR. We investigated the association between hemoglobin levels and DR risk. This cross-sectional, population-based study utilized data from 2,123 type 2 DM patients aged ≥30 years who participated in the Korea National Health and Nutrition Examination Survey from 2008 to 2012. Participants underwent an ophthalmic examination, including fundus photographs. A multiple logistic regression analysis was performed to evaluate the relationship between hemoglobin levels and DR risk. The mean hemoglobin levels in patients with and without DR were 13.76 ± 0.12 and 14.33 ± 0.05 g/dL, respectively, with anemia observed in 16.2 (2.4)% and 7.8 (0.8)%, respectively. A 19% decrease in DR risk was found with a 1.0-g/dL increase in hemoglobin level. DR risk exhibited a decreasing trend with increasing hemoglobin levels (P for trend <0.0001). The adjusted odds ratio of DR was significantly lower in the highest hemoglobin quartile. Our findings indicate that high hemoglobin levels are significantly related to a decreased DR risk in Korean type 2 diabetes.

Incidence and progression of diabetic retinopathy in Sub-Saharan Africa: A five year cohort study

Aims

To describe the incidence and progression of retinopathy in people with diabetes in Southern Malawi over 5 years. To document visual loss in a setting where laser treatment is not available.

Methods

Subjects from a cohort sampled from a hospital-based, primary-care diabetes clinic in 2007 were traced in 2012. Laser treatment was not available. Modified Wisconsin grading of retinopathy was performed using slit lamp biomicroscopy by a single ophthalmologist in 2007 and using four-field mydriatic fundus photographs at an accredited reading centre in 2012. Visual acuity was measured by Snellen chart in 2007 and by ‘Early Treatment of Diabetic Retinopathy Study’ chart in 2012. HbA1c, blood pressure, HIV status, urine albumin–creatinine ratio, haemoglobin and lipids were measured.

Results

Of 281 subjects recruited in 2007, 135 (48%) were traced and assessed, 15 were confirmed dead. At follow-up (median 5.3 years) ≥2 step retinopathy progression was observed in 48 subjects (36.4%; 95% CI 28.2–44.6). Incidence of sight threatening diabetic retinopathy for those with level 10 (no retinopathy) and level 20 (background) retinopathy at baseline, was 19.4% (11.3–27.4) and 81.3% (62.1–100), respectively. In multivariate analysis 2 step progression was associated with HbA1c (OR 1.2495%CI 1.04–1.48), and haemoglobin level (0.77, 0.62–0.98). 25 subjects (18.8%) lost ≥5 letters, 7 (5.3%) lost ≥15 letters.

Conclusions

Progression to sight threatening diabetic retinopathy from no retinopathy and background retinopathy was approximately 5 and 3 times that reported in recent European studies, respectively. Incidence of visual loss was high in a location where treatment was not available.

Impact of estimated glomerular filtration rate on diabetic macular edema

PURPOSE

Diabetic macular edema (DME) is a major cause of visual impairment in patients with diabetes and is influenced by various systemic factors. This study evaluates the effect of renal status on DME using estimated glomerular filtration rate (eGFR) as a study marker.

METHODS

This was a prospective observational cross-sectional study. One hundred and ninety-five patients of diabetic retinopathy (DR) were included. Group 1 had patients of DR without DME (n = 100), and group 2 had patients of DR with DME (n = 95). All patients were evaluated for DR/DME-related risk factors. eGFR was calculated in all patients. Spectral domain optical coherence tomography (SDOCT) was done to identify the various patterns and severity of DME.

RESULTS

Group 2 patients had significantly higher comorbidities than those in group 1 (p < 0.001). Hba1c, total cholesterol, triglycerides, LDL/HDL ratio, systolic and diastolic blood pressures were significantly higher in group II (p < 0.001 in each). There was no significant difference between the groups in terms of blood urea, serum creatinine or eGFR. eGFR did not show a significant association with a specific SDOCT pattern or severity of DME.

CONCLUSION

Comorbidities are more common and more severe in patients with DME. However, eGFR as a marker was not useful in predicting either the severity or pattern of DME. eGFR, in its present form, may not be useful in the evaluation and management of patients with DME.

First Prospective Cohort Study of Diabetic Retinopathy from Sub-Saharan Africa: High Incidence and Progression of Retinopathy and Relationship to Human Immunodeficiency Virus Infection

PURPOSE

To describe the prevalence, incidence, and progression of retinopathy and to report associations with demographic, clinical, and biochemical variables in people with diabetes in Southern Malawi.

DESIGN

Prospective cohort study.

PARTICIPANTS

Subjects were systematically sampled from 2 primary care diabetes clinics.

METHODS

We performed the first prospective cohort study of diabetic retinopathy from Sub-Saharan Africa over 24 months. Visual acuity, glycemic control, blood pressure, human immunodeficiency virus (HIV) status, urine albumin-to-creatinine ratio, hemoglobin, and lipids were assessed. Retinopathy was graded at an accredited reading center using modified Wisconsin grading of 4-field mydriatic photographs.

MAIN OUTCOME MEASURES

Incidence of sight-threatening retinopathy and progression of retinopathy by 2 steps on the Liverpool Diabetic Eye Study Scale.

RESULTS

A total of 357 subjects were recruited to the 24-month cohort study. At baseline, 13.4% of subjects were HIV positive and 15.1% were anemic. The 2-year incidence of sight-threatening diabetic retinopathy (STDR) for subjects with level 10 (no retinopathy), level 20 (background), and level 30 (preproliferative) retinopathy at baseline was 2.7% (95% confidence interval [CI], 0.1-5.3), 27.3% (95% CI, 16.4-38.2), and 25.0% (95% CI, 0-67.4), respectively. In a multivariate logistic analysis, 2-step progression of diabetic retinopathy was associated with glycosylated hemoglobin (odds ratio [OR], 1.27; 95% CI, 1.12-1.45), baseline grade of retinopathy (OR, 1.39; 95% CI, 1.02-1.91), and HIV infection (OR, 0.16; 95% CI, 0.03-0.78). At 2 years, 17 subjects (5.8%) lost ≥15 letters.

CONCLUSIONS

Incidence of STDR was approximately 3 times that reported in recent European studies. The negative association of HIV infection with retinopathy progression is a new finding.

Lower Hemoglobin Concentration Is Associated with Retinal Ischemia and the Severity of Diabetic Retinopathy in Type 2 Diabetes

Aims. To assess the association of blood oxygen-transport capacity variables with the prevalence of diabetic retinopathy (DR), retinal ischemia, and macular oedema in patients with type 2 diabetes mellitus (T2DM). Methods. Cross-sectional, case-control study (N = 312) with T2DM: 153 individuals with DR and 159 individuals with no DR. Participants were classified according to the severity of DR and the presence of retinal ischemia or macular oedema. Hematological variables were collected by standardized methods. Three logistic models were adjusted to ascertain the association between hematologic variables with the severity of DR and the presence of retinal ischemia or macular oedema. Results. Individuals with severe DR showed significantly lower hemoglobin, hematocrit, and erythrocyte levels compared with those with mild disease and in individuals with retinal ischemia and macular oedema compared with those without these disorders. Hemoglobin was the only factor that showed a significant inverse association with the severity of DR [beta-coefficient = -0.52, P value = 0.003] and retinal ischemia [beta-coefficient = -0.49, P value = 0.001]. Lower erythrocyte level showed a marginally significant association with macular oedema [beta-coefficient = -0.86, P value = 0.055]. Conclusions. In patients with DR, low blood oxygen-transport capacity was associated with more severe DR and the presence of retinal ischemia. Low hemoglobin levels may have a key role in the development and progression of DR.

Updates in the management of diabetic macular edema

Diabetes mellitus is a chronic disease which has multiple effects on different end-organs, including the retina. In this paper, we discuss updates on diabetic macular edema (DME) and the management options. The underlying pathology of DME is the leakage of exudates from retinal microaneurysms, which trigger subsequent inflammatory reactions. Both clinical and imaging techniques are useful in diagnosing, classifying, and gauging the severity of DME. We performed a comprehensive literature search using the keywords "diabetes," "macula edema," "epidemiology," "pathogenesis," "optical coherence tomography," "intravitreal injections," "systemic treatment," "hypertension," "hyperlipidemia," "anemia," and "renal disease" and collated a total of 47 relevant articles published in English language. The main modalities of treatment currently in use comprise laser photocoagulation, intravitreal pharmacological and selected systemic pharmacological options. In addition, we mention some novel therapies that show promise in treating DME. We also review systemic factors associated with exacerbation or improvement in DME.

Association of systemic and ocular risk factors with neurosensory retinal detachment in diabetic macular edema: a case-control study

Background

Diabetic macular edema (DME) with neurosensory retinal detachment (NSD) remains an important cause of visual loss in patients with diabetes. The aim of the study was to elucidate the association of systemic and ocular risk factors with NSD in DME.

Methods

In a retrospective case–control study, we reviewed clinical records of all the subjects with DME seen between January 2010 and December 2010. Cases and controls were selected based on optical coherence tomography and stereoscopic biomicroscopy review. NSD was defined as subfoveal fluid accumulation under detached retina with or without overlying foveal thickening. The association between the presence of NSD, blood pressure, lipid status and various other biochemical parameters was evaluated.

Results

Group I (cases) included 37 eyes of 33 patients having DME with NSD and Group II (controls) included 30 eyes of 21 patients having DME without NSD. Patients ranged in age (mean ± SD) from 50 to 62 years (56.6 +/-6.78) for cases and from 51 to 65 years (58.4+/-7.84) for controls. The duration of diabetes ranged from 4 to 15 year (mean 9.45+/-6.08) among cases and 4 to 14 years (9.7+/-5.12) among controls. Significant risk factors for NSD were high values of systolic and diastolic blood pressure (p = 0.039 and 0.043 respectively).

Conclusion

High systolic and diastolic blood pressures are independent and significant risk factors for NSD in DME.

Association of RAGE (p.Gly82Ser) and MnSOD (p.Val16Ala) polymorphisms with diabetic retinopathy in T2DM patients from north India

AIMS

The present study aimed to examine the association of RAGE (p.Gly82Ser) and MnSOD (p.Val16Ala) polymorphisms with diabetic retinopathy (DR) in north Indian T2DM patients.

METHODS

In this case-control association study, 758 T2DM patients were recruited. 446 with retinal neovascularization, microneurysms and hemorrhages were considered as cases (DR) and 312 patients with T2DM and no clinical signs of retinopathy (DNR), were recruited as controls. Genotypes for RAGE (p.Gly82Ser) and MnSOD (p.Val16Ala) polymorphisms were generated by direct sequencing of amplified products.

RESULTS

Genotype distribution of p.Gly82Ser (RAGE) and p.Val16Ala (MnSOD) polymorphisms were significantly different between DR and DNR (p<0.05) whereas distribution of allele frequency did not differ significantly (p>0.05). A significantly higher frequency of homozygous Ser82 genotype in DR patients was detected compared with DNR (2.4% vs 0.64%) for p.Gly82Ser (RAGE) polymorphism whereas there was a higher frequency of homozygous Ala16 genotype for p.Val16Ala (MnSOD) polymorphism in DR patients compared with DNR (22.6% vs 19.3%). Binary logistic analyses showed an association of homozygous recessive genotype Ser82 with DR (OR: 2.63%, 95% CI: 0.16-15.88, p<0.033) for p.Gly82Ser (RAGE) polymorphism. However, we did not find a significant association of p.Val16Ala polymorphism in MnSOD with retinopathy.

CONCLUSIONS

The findings indicate a statistically significant association of p.Gly82Ser polymorphism in RAGE with DR in T2DM patients.

Should we start all patients with diabetic retinopathy on fenofibrates?

There remains a need for strategies that are effective in preventing diabetic retinopathy (DR) or slowing down its progression, which is safe, well-tolerated, and more effective, have a lower risk profile, easy to perform, have more predictable results with less morbidity than the current regimens. Physicians caring for diabetic patients not only need to maximize glycemic control, but also closely monitor and treat other systemic conditions. The consistency of clinical data from the fenofibrate studies showed consistent beneficial effects with fenofibrate in slowing the progression of DR. They demonstrated significant benefit on micro-vascular (i.e., retinopathy and nephropathy) outcome, possibly independent of lipid levels. Can we combine the effectiveness of the current standard procedures with the prevention and slowing down of progression of DR that fenofibrates can offer? Knowledge of the primary mode of action of fenofibrate will be useful for both physicians and patients in determining how best to use this drug as an adjunct in the management of DR and ultimately facilitating the translation of clinical trial data to clinical practice.

Predictors of diabetic retinopathy in patients with type 2 diabetes who have normoalbuminuria

Background:

Microalbuminuria is an independent predictor of retinopathy, so absence of microalbuminuria may tend clinician not to screen for diabetic retinopathy (DR).

Aim:

The aim of our study was to estimate prevalence of DR in patients with type 2 diabetes who have normoalbuminuria, and to study predictors for DR, which can identify these high-risk individuals.

Subjects and Methods:

In a prospective cross-sectional study that included patients with type 2 DM and normoalbuminuria. Diagnosis of DR was made by a trained ophthalmologist based on the presence of clinical features in the fundus of both eyes following the International Clinical DR guidelines. The statistical analyses were performed using Statistical Package for the Social Sciences 15.0 version software (Chicago, IL, USA). The continuous variables expressed as means (SD and Student's t-test or Mann–Whitney test were used, as appropriate, to determine differences in them. Categorical variables were presented as percentage. The Pearson's Chi-square test or Fisher's exact test, as appropriate, was used to determine the differences in them.

Results:

A total of 226 patients with type 2 DM and normoalbuminuria were enrolled in the study that included 110 males (48.6%), and 116 females (51.4%) Mean (SD) duration of diabetes was 8.2 (5.6) years. DR of any grade was present in 49/226 (22%) patients. Of the patients with DR of any grade, 31/49 (63%) had mild non-proliferative diabetic retinopathy (NPDR) 10/49 (22%) had moderate to severe NPDR and 8/49 (15%) had PDR. Duration of diabetes (OR 1.01, 95% CI, 0.86-2.2, P = 0.04), higher systolic blood pressure (OR 2.2, 95% CI, 1.6-4.5, P = 0.01), low hemoglobin (OR 1.4, 95% CI, 0.45-2.9, P = 0.01), and a higher tertile of urinary albumin excretion rate (OR 4.12, 95% CI, 1.92-7.57, P = 0.001) had independently significant association with DR.

Conclusion:

The risk of DR exists in patients with type 2 diabetes even in normoalbuminuric individuals. Close monitoring is particularly needed if patients have longer duration of diabetes, hypertension, anemia, or high normal albuminuria.

Four-year incidence of diabetic retinopathy in a Spanish cohort: the MADIABETES study

Objective

To evaluate the incidence of diabetic retinopathy in patients with Type 2 Diabetes Mellitus, to identify the risk factors associated with the incidence of retinopathy and to develop a risk table to predict four-year retinopathy risk stratification for clinical use, from a four-year cohort study.

Design

The MADIABETES Study is a prospective cohort study of 3,443 outpatients with Type 2 Diabetes Mellitus, sampled from 56 primary health care centers (131 general practitioners) in Madrid (Spain).

Results

The cumulative incidence of retinopathy at four-year follow-up was 8.07% (95% CI = 7.04–9.22) and the incidence density was 2.03 (95% CI = 1.75–2.33) cases per 1000 patient-months or 2.43 (95% CI = 2.10–2.80) cases per 100 patient-years. The highest adjusted hazard ratios of associated risk factors for incidence of diabetic retinopathy were LDL-C >190 mg/dl (HR = 7.91; 95% CI = 3.39–18.47), duration of diabetes longer than 22 years (HR = 2.00; 95% CI = 1.18–3.39), HbA1c>8% (HR = 1.90; 95% CI = 1.30–2.77), and aspirin use (HR = 1.65; 95% CI = 1.22–2.24). Microalbuminuria (HR = 1.17; 95% CI = 0.75–1.82) and being female (HR = 1.12; 95% CI = 0.84–1.49) showed a non-significant increase of diabetic retinopathy. The greatest risk is observed in females who had diabetes for more than 22 years, with microalbuminuria, HbA1c>8%, hypertension, LDL-Cholesterol >190 mg/dl and aspirin use.

Conclusions

After a four-year follow-up, the cumulative incidence of retinopathy was relatively low in comparison with other studies. Higher baseline HbA1c, aspirin use, higher LDL-Cholesterol levels, and longer duration of diabetes were the only statistically significant risk factors found for diabetic retinopathy incidence. This is the first study to demonstrate an association between aspirin use and diabetic retinopathy risk in a well-defined cohort of patients with Type 2 Diabetes Mellitus at low risk of cardiovascular events. However, further studies with patients at high cardiovascular and metabolic risk are needed to clarify this issue.

Risk factors associated with diabetic macular edema

Diabetic macular edema (DME) is the most common cause of vision loss in patients with type 1 and type 2 diabetes. Glycemic control, hypertension, and dyslipidemia are known to be important risks factors for DME. In addition, nephropathy, anemia, sleep apnea, glitazone usage, and pregnancy are also important modifiable risk factors. It is important for physicians of different subspecialties to work together and understand multiple aspects of DME and diabetic healthcare.

Anemia as a factor related to the progression of proliferative diabetic retinopathy after photocoagulation

OBJECTIVE

This study aimed to investigate factors that could be related to the progression of proliferative diabetic retinopathy in patients treated with photocoagulation.

METHODS

In this case-control study, a total of 106 patients with diabetic retinopathy participated who were treated with photocoagulation. We analyzed glycaemia, serum cholesterol, triglycerides, hemoglobin, platelet levels, blood pressure measurement, diabetes duration, diabetes and hypertension treatment, sex, and age. The statistical analysis was done with t test, χ² test, odds ratio (OR), and simple linear regression.

RESULTS

We found statistical significance in blood glucose level(P=.038), cholesterol level (P<.001), and hemoglobin level (P<.001). The simple linear regression was significant with blood glucose level (P<.05) and hemoglobin level (P=.001). Hemoglobin had a significant result: OR=2.432, 95% CI 1.902-3.115; Pearson χ²=16.812; P<.001.

CONCLUSIONS

Anemia is an important finding in diabetic patients. Anemia is a relevant factor related to the progression of proliferative diabetic retinopathy, which can be treated with photocoagulation.

Predictors for diabetic retinopathy in normoalbuminuric people with type 2 diabetes mellitus

BACKGROUND

Previous studies have reported that microalbuminuria is an independent risk factor for the prevalence of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (DM). For this reason, the clinical significance of DR in normoalbuminuric type 2 DM patients may be overlooked. The aim of this study was to investigate the prevalence of DR and predictors for DR in normoalbuminuric patients with type 2 DM.

METHODS

A total 310 patients with type 2 DM and normoalbuminuria, who were referred to the Department of Ophthalmology for screening of DR were included in this study. DR was clinically graded according to the International Clinical Diabetic Retinopathy guidelines. The urinary albumin excretion rate (UAER) was assessed via 24-hour urine collection and measured by immunoturbidimetric assay. Normoalbuminuria was defined as a UAER < 20 μg/min in 2 out of 3 consecutive tests taken within 2-3 months.

RESULTS

DR of any grade was present in 64/310 (20.7 %) patients. Mild non-proliferative diabetic retinopathy (NPDR) was most prevalent in patients with DR of any grade (36/64, 56 %). The duration of diabetes (OR 1.01, 95 % CI, 1.01 - 1.02, p < 0.001), hemoglobin levels (OR 0.73, 95 % CI, 0.59 - 0.91, p = 0.004) and a higher tertile of UAER (OR 4.04, 95 % CI, 1.71 - 9.57, p = 0.001) had independently significant association with DR. NPDR as well as PDR was more prevalent in patients with higher tertile of UAER compared with those with lower tertile of UAER (NPDR, p = 0.002 and PDR, p = 0.027, respectively).

CONCLUSIONS

Our findings suggest that patients with normoalbuminuric type 2 DM also require close monitoring for the early detection of DR, especially if they have a higher UAER, longer duration of diabetes, or lower hemoglobin levels.

Factors associated with diabetic retinopathy in chinese patients with type 2 diabetes mellitus

Objective. To investigate the risk factors of DR in Chinese T2DM patients. Methods. 2009 patients with T2DM were included in this cross-sectional study. All patients underwent eye examination, and the DR stage was defined by an ophthalmologist. Correlation analysis was performed to evaluate the relation between DR and clinical variables. Logistic regression models were used to assess risk for those factors associated with DR. Results. A total of 597 T2DM patients (29.7%) had DR, of which 548 (27.3%) were nonproliferative diabetic retinopathy and 49 (2.4%) were proliferative diabetic retinopathy. Positive correlations were found between DR and duration of diabetes, systolic blood pressure (SBP), diastolic blood pressure, glycated hemoglobin, glycated albumin, 24 hurinary albumin excretion, peripheral atherosclerosis (PA), diabetes nephropathy (DN), diabetic peripheral neuropathy, and anemia. Negative correlations were found between DR and C-peptide and glomerular filtration rate. Logistic regression analysis revealed that duration of diabetes, SBP, DN, anemia, PA, and C-peptide were each independent risk factors of DR. Conclusion. The duration of diabetes, SBP, DN, anemia, and PA are positively associated with DR in Chinese T2DM patients, while C-peptide is negatively associated with DR. Monitoring and evaluation of these related factors will likely contribute to the prevention and treatment of DR.