Prevalence and risk factors of diabetic retinopathy among noninsulin-dependent diabetic subjects

Single-Field Fundus Photography for Screening of Diabetic Retinopathy: The Prevalence and Associated Factors in a Population-Based Study

INTRODUCTION

We aimed to determine the prevalence and risk factors for diabetic retinopathy (DR) in a multi-primary healthcare facilities-based DR screening project by analyzing single-field fundus photographs among patients with diabetes in Rafsanjan City, Iran, based on the Rafsanjan Cohort Study, as a part of the prospective epidemiological research studies in IrAN (PERSIAN).

METHODS

Of all participants in the Rafsanjan Cohort Study (performed in four primary healthcare facilities across Rafsanjan City from August 2015 to December 2017), patients with diabetes were recruited in this study. All participants underwent a standardized interview and clinical and paraclinical examinations for demographic characteristics, and medical conditions according to the PERSIAN's protocols. In addition, digital fovea-centered and single-field fundus photography was performed for DR identification and grading. For assessment of agreement, a subgroup of participants underwent fundus examination, randomly. DR was graded as nonproliferative (NPDR) or proliferative (PDR).

RESULTS

Of 8414 screened participants, 1889 had diabetes. The total prevalence of DR was 6.93% [131 individuals including 110 (5.82%) with NPDR, and 21 (1.11%) with PDR] based on single-field fundus photographs, with almost perfect agreement with fundus examinations (κ = 0.82). On adjusted multivariate analysis, duration of diabetes (OR 1.16, 95% CI 1.13-1.19), positive family history for diabetes (OR 1.73, 95% CI 1.09-2.75), fasting plasma glucose (FPG) ≥ 126 mg/dL (OR 1.98, 95% CI 1.16-3.39), and serum creatinine level (OR 1.79, 95% CI 1.08-2.98) were associated with DR. Factors including age, education level, physical activity, body mass index, hypertension, and cardiovascular and renal diseases did not have association with DR on adjusted multivariate analysis.

CONCLUSIONS

Single-field fundus photography can be used for screening of DR in primary healthcare facilities. In individuals with diabetes, duration of diabetes, positive family history for diabetes, FPG ≥ 126 mg/dL, and serum creatinine level may be associated with DR.

Retinopathy risk calculators in the prediction of sight-threatening diabetic retinopathy in type 2 diabetes: A FIELD substudy

AIMS

To evaluate the risk algorithm by Aspelund et al. for predicting sight-threatening diabetic retinopathy (STDR) in Type 2 diabetes (T2D), and to develop a new STDR prediction model.

METHODS

The Aspelund et al. algorithm was used to calculate STDR risk from baseline variables in 1012 participants in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) ophthalmological substudy, compared to on-trial STDR status, and receiver operating characteristic analysis performed. Using multivariable logistic regression, traditional risk factors and fenofibrate allocation as STDR predictors were evaluated, with bootstrap-based optimism-adjusted estimates of predictive performance calculated.

RESULTS

STDR developed in 28 participants. The Aspelund et al. algorithm predicted STDR at 2- and 5-years with area under the curve (AUC) 0.86 (95% CI 0.77-0.94) and 0.86 (0.81-0.92), respectively. In the second model STDR risk factors were any DR at baseline (OR 24.0 [95% CI 5.53-104]), HbA1c (OR 1.95 [1.43-2.64]) and male sex (OR 4.34 [1.32-14.3]), while fenofibrate (OR 0.13 [0.05-0.38]) was protective. This model had excellent discriminatory ability (AUC = 0.89).

CONCLUSIONS

The algorithm by Aspelund et al. predicts STDR well in the FIELD ophthalmology substudy. Logistic regression analysis found DR at baseline, male sex, and HbA1c were predictive of STDR and, fenofibrate was protective.

Prevalence of blindness and its determinants in Bangladeshi adult population: results from a national cross-sectional survey

OBJECTIVE

The objective of this study was to determine the prevalence of blindness and its determinants in Bangladeshi adult population.

STUDY DESIGN

A cross-sectional population-based survey conducted at household level with national representation. Samples were drawn from the 2011 national census frame using a multistage stratified cluster sampling method.

SETTING AND PARTICIPANTS

The survey was done in urban and rural areas in 2013 using a probability proportionate to size sampling approach to locate participants from 72 primary sampling units. One man or one woman aged ≥40 years was randomly selected from their households to recruit 7200. In addition to sociodemographic data, information on medication for hypertension and diabetes was obtained. Blood pressure and capillary blood glucose were measured. Eyelids, cornea, lens, and retina were examined in addition to visual acuity and refraction testing.

PRIMARY OUTCOME MEASURES

The following definition was used to categorise subjects having (1) blindness: visual acuity <3/60, (2) low vision: ≥3/60 to <6/60 and (3) normal vision: ≥6/12 after best correction.

RESULTS

We could recruit 6391 (88.8%) people among whom 2955 (46.2%) were men. Among them, 1922 (30.1%) were from urban and 4469 (69.9%) were from rural areas. The mean age was 54.3 (SD 11.2) years. The age-standardised prevalence, after best correction, of blindness and low vision was 1.0% (95% CI 0.5% to 1.4%) and 12.1% (95% CI 10.5% to 13.8%), respectively. Multivariable logistic regression indicated that cataract, age-related macular degeneration and diabetic retinopathy were significantly associated with low vision and blindness after adjustment for age and sex. Population attributable risk of cataract for low vision and blindness was 79.6%.

CONCLUSIONS

Low vision and blindness are common problems in those aged 40 years or older. Extensive screening and eye care services are necessary for wider coverage engaging all tiers of the healthcare system especially focusing on cataract.

The Importance of Close Follow-Up in Patients with Early-Grade Diabetic Retinopathy: A Taiwan Population-Based Study Grading via Deep Learning Model

(1) Background: Diabetic retinopathy (DR) can cause blindness. Current guidelines on diabetic eye care recommend more frequent eye examinations for more severe DR to prevent deterioration. However, close follow-up and early intervention at earlier stages are important for the prevention of disease progression of other diabetes mellitus (DM) complications. The study was designed to investigate the association between different stages of DR in type 2 DM patients and the progression of DR; (2) Methods: A total of 2623 type 2 DM patients were included in this study. In these patients, a total of 14,409 fundus color photographs was obtained. The primary outcome was the progression of DR; (3) Results: The progression of DR was highly associated with the initial grade of DR (p < 0.001). Severe nonproliferative diabetic retinopathy (NPDR) was the most likely to progress to proliferative diabetic retinopathy (PDR), followed by moderate NPDR, mild NPDR, and no retinopathy. However, progression to the next stage of DR showed a different trend. We used no retinopathy as a reference. Mild NPDR showed the highest risk for progression to the next stage [hazard ratio (HR): 2.00 (95% conference interval (CI): 1.72–2.32)] relative to higher initial grades [HR (moderate NPDR): 1.82 (95% CI: 1.58–2.09) and HR (severe NPDR): 0.87 (95% CI: 0.69–1.09)]. The same trend was observed in the multivariate analysis, in which mild NPDR presented the highest risk for progression to the next stage (adjusted HR (mild NPDR): 1.95 (95% CI: 1.68–2.27), adjusted HR (moderate NPDR): 1.73 (95% CI: 1.50–1.99), and adjusted HR (severe NPDR): 0.82 (95% CI: 0.65–1.03)); (4) Conclusions: Type 2 diabetic patients with earlier-grade DR appeared to exhibit more rapid development to the next grade in our study. As these findings show, more frequent fundus color photography follow-up in earlier-grade DR patients is important to slow DR progression and awaken self-perception.

Global and Regional Prevalence of Diabetic Retinopathy; A Comprehensive Systematic Review and Meta-analysis

PURPOSE

We conducted a systematic search to estimate DR prevalence in different age and gender groups, and to evaluate the determinants of heterogeneity in its prevalence.

METHODS

A systematic and comprehensive search from inception to August 10, 2020, was done in international databases, including Scopus, PubMed, Web of Science, Embase, and other data sources without any restriction to find cross-sectional studies related to the prevalence of DR.

RESULTS

Of 6399 studies, 90 articles with a sample size of 563460 individuals and 204189 diabetic patients were analyzed. The estimated pooled prevalence of DR in the diabetic population in general; in female and in male was 28.41% (95% CI: 25.98 to 30.84); 25.93% (95% CI: 23.54 to 28.31) and 28.95% (95% CI: 26.57 to 31.32); respectively and the prevalence of DR showed no inter-gender difference. The heterogeneity of the pooled prevalence according to I² was 99% (p < .001). According to the meta-regression results, the variables of WHO region (Coefficient of AMRO vs SEARO: 15.56; p: 0.002), age (Coefficient of above 60 years vs below 40 year: 18.67; p: 0.001), type of DR (Coefficient: 19.01; p < .001), and publication year (Coefficient: -0.60; p: 0.001) had a significant correlation with heterogeneity.

CONCLUSION

One third of diabetic patients suffered from DR, mostly NPDR. DR increased markedly after the age of 60 years, which could be due to the longer duration of diabetes. Age, WHO region, type of DR, and publication year affected the heterogeneity in the prevalence of DR.

Global Prevalence of Diabetic Retinopathy and Projection of Burden through 2045: Systematic Review and Meta-analysis

TOPIC

To provide updated estimates on the global prevalence and number of people with diabetic retinopathy (DR) through 2045.

CLINICAL RELEVANCE

The International Diabetes Federation (IDF) estimated the global population with diabetes mellitus (DM) to be 463 million in 2019 and 700 million in 2045. Diabetic retinopathy remains a common complication of DM and a leading cause of preventable blindness in the adult working population.

METHODS

We conducted a systematic review using PubMed, Medline, Web of Science, and Scopus for population-based studies published up to March 2020. Random effect meta-analysis with logit transformation was performed to estimate global and regional prevalence of DR, vision-threatening DR (VTDR), and clinically significant macular edema (CSME). Projections of DR, VTDR, and CSME burden were based on population data from the IDF Atlas 2019.

RESULTS

We included 59 population-based studies. Among individuals with diabetes, global prevalence was 22.27% (95% confidence interval [CI], 19.73%-25.03%) for DR, 6.17% (95% CI, 5.43%-6.98%) for VTDR, and 4.07% (95% CI, 3.42%-4.82%) for CSME. In 2020, the number of adults worldwide with DR, VTDR, and CSME was estimated to be 103.12 million, 28.54 million, and 18.83 million, respectively; by 2045, the numbers are projected to increase to 160.50 million, 44.82 million, and 28.61 million, respectively. Diabetic retinopathy prevalence was highest in Africa (35.90%) and North American and the Caribbean (33.30%) and was lowest in South and Central America (13.37%). In meta-regression models adjusting for habitation type, response rate, study year, and DR diagnostic method, Hispanics (odds ratio [OR], 2.92; 95% CI, 1.22-6.98) and Middle Easterners (OR, 2.44; 95% CI, 1.51-3.94) with diabetes were more likely to have DR compared with Asians.

DISCUSSION

The global DR burden is expected to remain high through 2045, disproportionately affecting countries in the Middle East and North Africa and the Western Pacific. These updated estimates may guide DR screening, treatment, and public health care strategies.

The Prevalence of Diabetic Microvascular Complications in China and the USA

PURPOSE OF REVIEW

Diabetes can lead to development of devastating microvascular complications, such as nephropathy, retinopathy, and peripheral sensory and autonomic neuropathy. While China and the USA both face the threat of this major public health challenge, the literature is limited in describing similarities and differences in the prevalence, and risk factors for the development, of diabetic microvascular complications between these two countries.

RECENT FINDINGS

The current review discusses the following: (1) the most recent evidence on prevalence of diabetic microvascular complications in China and the USA (including downtrends of diabetes retinopathy and neuropathy in the USA); (2) differences in patient risk factors of these complications; (3) challenges and current knowledge gaps (such as lacking national epidemiological data of diabetic complications in China); and (4) potential future clinical and research opportunities (including needs in diabetes evaluation and management in remote areas and standardization of methods in evaluating diabetic complications across countries). Diabetic microvascular complications remain to be health threats in both China and the USA. Further investigations are needed for comprehensive understanding and effect prevention and management of these complications.

The Clinical Influence after Implementation of Convolutional Neural Network-Based Software for Diabetic Retinopathy Detection in the Primary Care Setting

Deep learning-based software is developed to assist physicians in terms of diagnosis; however, its clinical application is still under investigation. We integrated deep-learning-based software for diabetic retinopathy (DR) grading into the clinical workflow of an endocrinology department where endocrinologists grade for retinal images and evaluated the influence of its implementation. A total of 1432 images from 716 patients and 1400 images from 700 patients were collected before and after implementation, respectively. Using the grading by ophthalmologists as the reference standard, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) to detect referable DR (RDR) were 0.91 (0.87-0.96), 0.90 (0.87-0.92), and 0.90 (0.87-0.93) at the image level; and 0.91 (0.81-0.97), 0.84 (0.80-0.87), and 0.87 (0.83-0.91) at the patient level. The monthly RDR rate dropped from 55.1% to 43.0% after implementation. The monthly percentage of finishing grading within the allotted time increased from 66.8% to 77.6%. There was a wide range of agreement values between the software and endocrinologists after implementation (kappa values of 0.17-0.65). In conclusion, we observed the clinical influence of deep-learning-based software on graders without the retinal subspecialty. However, the validation using images from local datasets is recommended before clinical implementation.

Impact of age at type 2 diabetes mellitus diagnosis on mortality and vascular complications: systematic review and meta-analyses

AIMS/HYPOTHESIS

Few studies examine the association between age at diagnosis and subsequent complications from type 2 diabetes. This paper aims to summarise the risk of mortality, macrovascular complications and microvascular complications associated with age at diagnosis of type 2 diabetes.

METHODS

Data were sourced from MEDLINE and All EBM (Evidence Based Medicine) databases from inception to July 2018. Observational studies, investigating the effect of age at diabetes diagnosis on macrovascular and microvascular diabetes complications in adults with type 2 diabetes were selected according to pre-specified criteria. Two investigators independently extracted data and evaluated all studies. If data were not reported in a comparable format, data were obtained from authors, presented as minimally adjusted ORs (and 95% CIs) per 1 year increase in age at diabetes diagnosis, adjusted for current age for each outcome of interest. The study protocol was recorded with PROSPERO International Prospective Register of Systematic Reviews (CRD42016043593).

RESULTS

Data from 26 observational studies comprising 1,325,493 individuals from 30 countries were included. Random-effects meta-analyses with inverse variance weighting were used to obtain the pooled ORs. Age at diabetes diagnosis was inversely associated with risk of all-cause mortality and macrovascular and microvascular disease (all p < 0.001). Each 1 year increase in age at diabetes diagnosis was associated with a 4%, 3% and 5% decreased risk of all-cause mortality, macrovascular disease and microvascular disease, respectively, adjusted for current age. The effects were consistent for the individual components of the composite outcomes (all p < 0.001).

CONCLUSIONS/INTERPRETATION

Younger, rather than older, age at diabetes diagnosis was associated with higher risk of mortality and vascular disease. Early and sustained interventions to delay type 2 diabetes onset and improve blood glucose levels and cardiovascular risk profiles of those already diagnosed are essential to reduce morbidity and mortality. Graphical abstract.

The Related Risk Factors of Diabetic Retinopathy in Elderly Patients with Type 2 Diabetes Mellitus: A Hospital-Based Cohort Study in Taiwan

Diabetic retinopathy (DR), caused by small vessel disease, is the main cause of blindness in persons with diabetes. Taiwan is one of the Asian countries with the highest prevalence rate of DR. The purpose was to investigate the related risk factors of DR in elderly patients with type 2 diabetes mellitus (T2DM), in Lee's Endocrinology Clinic. 792 T2DM patients over 60 years old were invited to have an outpatient visit at least every three months, and all of them were asked to undergo a standardized interview and collect their blood samples. Significant factors were being female (adjusted hazard ratio (HR): 1.287; 95% CI, 1.082-1.531), higher glycated hemoglobin (HbA1c) (HR: 1.067; 95% CI: 1.016-1.119), higher mean low density of lipoprotein cholesterol (LDL-c) (HR: 1.004; 95% CI: 1.001-1.006), and chewing betel nut (HR: 1.788; 95% CI: 1.362-2.347). This study showed that gender, the behavior of chewing betel nut, HbA1c, and LDL-c are important factors for the development of DR in elderly patients with T2DM. It is suggested that patients should control their HbA1c and LDL-c and quit chewing betel nut to prevent DR. This suggestion applies especially to female patients.

Knowledge and practices regarding diabetic retinopathy among diabetic patients registered in a chronic disease management system in eastern China

PURPOSE

To investigate the knowledge and practices regarding diabetic retinopathy (DR) among diabetic patients included in a community-based primary health system (CBPHS) in China.

METHODS

Diabetic patients aged 18 years and above registered in the CBPHS in Yueqing city, Zhejiang province were recruited. Information obtained by questionnaire included: demographic and socioeconomic status, knowledge about DR, and ocular and medical history. The primary outcome was whether the participant knew that DM can affect the eyes, defined according to the question: "Do you know diabetes mellitus (DM) can affect eyes? (yes or no)". A knowledge score was calculated based on the responses to seven questions, with 1 point awarded for a correct response and 0 points for an incorrect or uncertain answer.

RESULTS

A total of 1972 diabetic patients were included in the study with an average age of 65.2±10.8 years, 45.7% were male. One thousand two hundred and nineteen patients (61.8%) knew that DM can affect the eyes. Significant differences in age, education, income status, insurance covering eye care, fasting blood glucose, duration of DM, history of hypertension existed between subjects who knew and those who did not know that DM can affect the eyes (P<0.05 for all). The proportion of correct answers to the DR knowledge questions ranged from 33.3% to 61.8%, with an average score of 3.65±2.47. In the multiple regression analysis, the knowledge score was significantly associated with age, education, income, history of hypertension, duration of DM, being told that regular examinations should be performed and concern about vision loss (P <0.01 for all).

CONCLUSIONS

The knowledge toward DR among DM patients were still low within the chronic disease management system in eastern China. Routine ophthalmic screening, health care promotions, and educational programs should be emphasized and implemented for better DR prevention and management.

Vascular changes in diabetic retinopathy-a longitudinal study in the Nile rat

Diabetic retinopathy is the most common microvascular complication of diabetes and is a major cause of blindness, but an understanding of the pathogenesis of the disease has been hampered by a lack of accurate animal models. Here, we explore the dynamics of retinal cellular changes in the Nile rat (Arvicanthis niloticus), a carbohydrate-sensitive model for type 2 diabetes. The early retinal changes in diabetic Nile rats included increased acellular capillaries and loss of pericytes that correlated linearly with the duration of diabetes. These vascular changes occurred in the presence of microglial infiltration but in the absence of retinal ganglion cell loss. After a prolonged duration of diabetes, the Nile rat also exhibits a spectrum of retinal lesions commonly seen in the human condition including vascular leakage, capillary non-perfusion, and neovascularization. Our longitudinal study documents a range and progression of retinal lesions in the diabetic Nile rat remarkably similar to those observed in human diabetic retinopathy, and suggests that this model will be valuable in identifying new therapeutic strategies.

Diabetes-related kidney, eye, and foot disease in Taiwan: An analysis of nationwide data from 2005 to 2014

BACKGROUND/PURPOSE

Patients with diabetes have a higher risk of developing chronic complications and cause a huge burden to the public health care system as well as on patients and their families. We studied these diabetic complications about kidney, eye and peripheral vascular diseases to understand their prevalence and distributions in a national survey.

METHODS

We analyzed diabetic complications using National-Health-Insurance claims filed from 2005 to 2014. We used this database to evaluate their developments of kidney, eye, and peripheral vascular diseases according to the International-Classification-of-Diseases, Ninth Revision using clinical modification diagnosis codes.

RESULTS

The prevalence of diabetic kidney disease (DKD) significantly increased from 10.49% to 17.92% from 2005 to 2014. The prevalence rate of diabetic foot significantly decreased from 1.34% to 1.05% from 2005 to 2014, and the rate of severe infection also significantly decreased from 50.69% to 45.85%. The amputation rate significantly decreased from 24.91% to 17.47% among all patients with diabetic foot.

CONCLUSION

In this study, the trends in DKD and dialysis prevalence were similar to those of the 2012 report. The rate of increase in dialysis prevalence is lower in this study than in the 2012 report. The prevalence of diabetic foot, severe infection, and amputation in this report exhibited significantly decreasing trends. This improvement may be attributable to care from multidisciplinary teams. We should dedicate more resources to our prevention program of DKD and retinopathy to further improve outcomes in the future.

Systemic Factors Related to Intraocular Levels of Interleukin-6 and Vascular Endothelial Growth Factor in Diabetic Retinopathy

This study is for identifying systemic factors correlating with intraocular levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in diabetic retinopathy. Forty-two consecutive patients undergoing pars plana vitrectomy (PPV) for PDR were included in this cross-sectional study. The aqueous humor was sampled just prior to PPV for assay of IL-6 and VEGF. One day before PPV, patient characteristics were recorded and a number of systemic markers were amassed, including fasting and postprandial glucose, homeostasis model assessment- (HOMA-) IR, HOMA-beta, C-peptide, insulin, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein- (Apo-) A, Apo-B, and lipoprotein A (Lp-A). Relationships between systemic determinants and intraocular cytokine levels were analyzed by regression analysis. Mean levels of IL-6 and VEGF were 15.3 pg/mL (range, 2.4–10124.5 pg/mL) and 21.1 pg/mL (range, 3.2–766.1 pg/mL), respectively. After adjustment for age, gender, duration of diabetes, and BMI, multivariate analysis showed significant association of smoking (p=0.002) and HOMA-IR (p=0.003) with intraocular IL-6 levels, while intraocular VEGF and systemic Lp-A levels correlated significantly (p=0.032). Insulin resistance and smoking status impacted intraocular levels of IL-6, while intraocular VEGF levels were influenced by Lp-A. An appreciation for the relationship between systemic factors and intraocular cytokines may help elucidate the complex pathophysiology of diabetic retinopathy.

Factors associated with retinal screening among patients with diabetes in Taiwan

PURPOSE

The purpose of this study is to explore the factors associated with having a diabetic retinopathy exam (DRE) during the past 2 years among patients with diabetes.

METHODS

Patients visiting the eye clinic at Shin-Kong Memorial Hospital in Taipei were enrolled in this study from January to June 2009. A total of 313 patients participated in this study. Excluding patients with missing responses for more than three questions (38) yielded a final sample of 275 participants. Chi-square and Mann-Whitney U-tests were used for bivariate analysis. Multivariable logistic regression examined factors associated with having a DRE controlling for demographic and health factors.

RESULTS

Although 83% of participants said that their physician suggested DRE, only 60% were screened during the past 2 years. In response to the question about why patients did not seek a DRE exam, 43.2% reported that they did not know having this exam was necessary. In adjusted results, receiving information about the relationship between diabetes and retinopathy from medical staff and believing that diabetes could damage the vision were associated with having a DRE in the past 2 years (both P < 0.05).

CONCLUSIONS

Although most patients indicated that their physician suggested the need for eye care, a substantial percentage of patients with diabetes were not aware of the need for a regular DRE. Information about the relationship between diabetes and retinopathy and concerns about damage to vision were associated with greater likelihood of seeking a DRE. These factors should be considered to promote DR screening.

The prevalence of retinopathy among type 2 diabetic patients in Iran: A systematic review and meta-analysis

Diabetic retinopathy is one of the most major causes of blindness and disability in diabetic patients and imposes very high cost on Health Care System. Studies conducted in the country showed different and inconsistent prevalence of the disease. The study aims to determine the overall prevalence of retinopathy in patients with type 2 diabetes in Iran through a systematic review and meta-analysis. The present study was conducted via meta-analysis method during March, 2000 to October, 2018. The articles related to the subject under study were obtained from Magiran, SID, Medline (PubMed), Science Direct, Scopus and Google Scholar databases. I2 index was used to examine the heterogeneity of articles studied; and the data was analyzed by Comprehensive Meta-Analysis Software. Through the study of 34 articles and 17,079 individuals with age range of 5-83, the overall prevalence of retinopathy for type 2 diabetic patients in Iran and on the basis of meta-analysis, was obtained that was 37.8% (32.84-43%, 95% confidence interval); the highest prevalence of retinopathy for type 2 diabetic patients was in Tehran province with 78% (68.8-85.1%, 95% confidence interval) in 2006 and the lowest prevalence of retinopathy for type 2 diabetic patients was in Isfahan province with 9% (7.1-11.4, 95% confidence interval) in 2006; furthermore, the prevalence of retinopathy for type 2 diabetic patients in Iran increases with increased sample size that it was statistically significant (P < 0.05). Regarding the high prevalence of retinopathy for type 2 diabetic patients in the country, it is essential that health policy makers take effective measures to reduce the disease incidence in diabetic patients.

The association of smoking and risk of diabetic retinopathy in patients with type 1 and type 2 diabetes: a meta-analysis

PURPOSE

To clarify the relevance between smoking and diabetic retinopathy in patients with type 1 and type 2 diabetes mellitus.

METHODS

Published evidence were searched in MEDLINE and EMBASE from the databases began until Feb. 2017. Studies evaluating the association between smoking and diabetic retinopathy or evaluating the risk factors of diabetic retinopathy including smoking were included.

RESULTS

Totally 73 studies were identified, among which 19 studies included type 1 diabetes patients and 56 studies included type 2 diabetes patients. In type 1 diabetes, compare with non-smokers, the risk of diabetic retinopathy significantly increased in smokers (risk ratio (RR) = 1.23, 95% CI 1.14, 1.33, P < 0.001), and the risk of proliferative diabetic retinopathy also significantly increased in smokers (RR = 1.48, 95% CI 1.20, 1.81, P < 0.001). In type 2 diabetes, compare with non-smokers, the risk of diabetic retinopathy significantly decreased in smokers (RR = 0.92, 95% CI 0.86, 0.98, P = 0.02) and the risk of proliferative diabetic retinopathy also significantly decreased in smokers (RR = 0.68, 95% CI 0.61, 0.74, P < 0.001).

CONCLUSIONS

Compare with non-smokers, the risk of diabetic retinopathy significantly increased in smokers with type 1 diabetes while significantly decreased in smokers with type 2 diabetes. However, this result did not change the importance of smoking cessation for public health.

Review of the literature examining the association between physical activity and retinopathy

The main aim of this review was to evaluate the association between physical activity and retinopathy. Secondary aims included evaluating the association between sedentary behavior and retinopathy, and evaluating the association between physical activity/sedentary behavior on health outcomes among patients with existing retinopathy. Twenty-one articles met our criteria for inclusion in this review. Among the 19 studies evaluating the main aim (physical activity and retinopathy), 53% (n = 10/19) demonstrated evidence of a favorable (inverse) association between physical activity and retinopathy, 42% (n = 8/19) reported a null association physical activity and retinopathy, and 5% (n = 1/19) presented evidence for a detrimental association between physical activity and retinopathy. Regarding the secondary aims, one study demonstrated a detrimental association between sedentary behavior and retinopathy. Similarly, one study demonstrated that physical activity was protective against early mortality among those with mild retinopathy. This review identifies an 'indeterminate' association between physical activity and retinopathy. Too few studies evaluated the association between sedentary behavior and retinopathy or the effects of physical activity on health outcomes among those with existing retinopathy.

Factors Associated with Prevalent Diabetic Retinopathy in Chinese Americans: The Chinese American Eye Study

OBJECTIVE

To identify factors associated with prevalent diabetic retinopathy (DR) among Chinese American adults with type 2 diabetes mellitus (T2DM), and to compare these factors to ones previously described for a population-based sample of Latinos with a higher DR prevalence.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

4582 Chinese Americans aged 50 or older residing in Monterey Park, California.

METHODS

Participants completed an in-home questionnaire on socio-demographic status and medical history, and a comprehensive clinical eye examination, using the same protocol implemented in the Los Angeles Latino Eye Study. Fundus photographs from 7 Early Treatment Diabetic Retinopathy fields were graded in a masked manner using a modified Airlie House grading system to assess presence and severity of DR. Logistic regression analyses based on a conceptual model of DR risk identified factors associated with prevalent DR.

MAIN OUTCOME MEASURES

Odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with DR and vision-threatening DR (VTDR).

RESULTS

In total, 238 participants were diagnosed with any DR; 27 of these were classified as having VTDR. Both, any DR and VTDR showed statistically significant positive associations with T2DM duration (OR5-9 years = 1.24, OR10-14 years = 2.07, OR15+years = 3.99), glycosylated hemoglobin (HbA1c) (OR6.5-6.9% = 1.33, OR7-7.9% = 1.86, OR8%+ = 3.22), systolic blood pressure (SBP) (ORper 10mmHg+ = 1.19), and insulin treatment (ORinsulin+ = 2.44). For VTDR, we also found novel associations with antihypertensive drugs (OR: 0.18; 95% CI: 0.06-0.61) and statins (OR: 4.96; 95% CI: 1.60-16.41). Chinese Americans and Latinos had a nearly identical DR probability based on HbA1c and SBP. However, Latinos had a higher DR probability at every year of duration of T2DM (≥ 5 years).

CONCLUSIONS

While we observed an overall lower DR prevalence in Chinese Americans than in Latinos (35.8% of individuals with TD2M in Chinese Americans versus 42.0% in Latinos), our data indicate that the impact of increasing HbA1c and SBP on DR probability is incrementally the same in both populations. However, increasing T2DM duration is associated with higher DR probability in Latinos than Chinese Americans, even after controlling for other known predictors. Novel factors associated with VTDR include antihypertensive drugs and statins. However, to determine if these drugs impact VTDR susceptibility, we need longitudinal data and more cases.

Prevalence of Diabetic Retinopathy among Subjects with Known Diabetes in China: The Beijing Eye Study

Purpose

To evaluate the prevalence of diabetic retinopathy and risk factors among patients with self-reported diabetes mellitus in China.

Methods

The Beijing Eye Study, a population-based study on inhabitants aged 40+ years, included 4439 subjects. Fundus photographs of the worse eye from participants with self-reported diabetes were graded.

Results

Fundus photographs ready for evaluation and a filled out questionnaire were available for 4127 (93.0%) subjects. The prevalence of self-reported diabetes was 235/4127 (5.7%). Among the subjects with a self-reported diagnosis of diabetes, diabetic retinopathy was detected on the fundus photographs of 86 (37.1%) subjects, with macular edema in 12 (5.2%) subjects, clinically significant macular edema in 6 (2.6%) subjects, and a vision-threatening stage of the retinopathy in 12 (5.2%) subjects. Diabetic retinopathy was associated with rural region (p=0.004), longer duration of diabetes (p=0.009), use of diabetic medications (p=0.02), and lower education background (p=0.003).

Conclusions

Prevalence of diabetic retinopathy among Chinese patients aged 40+ years with a self-reported diagnosis of diabetes is about 37%, with a vision-threatening stage of the retinopathy detected in 5% of the subjects. About 5.7% of the adult Chinese population report on a known diagnosis of diabetes mellitus, with about 15% of these subjects knowing about the presence of diabetic retinopathy. The frequency of known diabetes mellitus is lower in rural regions than in urban regions, while diabetic retinopathy overall and macular edema among the subjects with known diabetes mellitus were significantly more common in the rural group.

Multiple deprivation, vision loss, and ophthalmic disease in adults: global perspectives

The association between socioeconomic position and morbidity and mortality has long been recognized. We evaluate the evidence for an association between multiple aspects of deprivation and ocular health in a global context. This is a systematic review of studies that evaluated deprivation in the adult population in the context of the major acquired causes of visual loss such as cataract, diabetic eye disease, glaucoma, age-related macular degeneration, and ocular trauma. The search strategy identified relevant studies reported between 1946 and August 2016, with randomized control trials, case-control, cohort, and cross-sectional study designs being selected for inclusion. The studies identified in this review from across the world demonstrate the extent to which the common themes such as low educational attainment and low income may be associated with increased incidence of various sight-threatening conditions and may adversely affect access to specialist assessment and delivery of treatment. Health inequality may always persist, but an increased recognition of the importance of the various impacts of deprivation may empower policy makers to target limited resources to the most vulnerable groups in order to deliver the greatest benefit.

Determining the Prevalence of Retinopathy and Its Related Factors among Patients with Type 2 Diabetes in Kerman, Iran

Objectives

To determine the prevalence of retinopathy and its associated factors in diabetic patients referred to a diabetes center in an Iranian city.

Methods

This was a cross-sectional, descriptive–analytical study in which a researcher-made checklist was used to collect the data of patients with type 2 diabetes in 2015. The statistical population consisted of 11,770 health records of diabetic patients registered in a second-level diabetes center. Of the 11,770 health records, 206 records with the most complete data about patients with type 2 diabetes were selected through census method. Chi-square test and logistic regression through SPSS were used for data analysis.

Results

In this study, 93/206 diabetic patients (45.1%) had retinopathy. Female sex, age over 60, lower education level, being housewife, family history of having diabetes, longer years of having the disease, and higher level of hemoglobin A1c (HbA1c) were associated with higher risk of retinopathy. However, the association was statistically significant only for the HbA1c level (p ≥ 0.05).

Conclusion

According to this study, HbA1c level is a predictor of diabetes complications. Therefore, it is necessary for health authorities to improve diabetes management through different strategies to prevent complications to control blood sugar effectively.

Diabetic retinopathy and the associated risk factors in diabetes type 2 patients in Abha, Saudi Arabia

Objectives:

To assess the proportion and grades of retinopathy and its risk factors in diabetes type 2 patients.

Materials and Methods:

This was a cross-sectional study of 401 type 2 diabetic patients. A questionnaire and checklist were used to collect the data. Retinopathy was diagnosed and graded by fundus photographs and slit lamp examination. The duration of diabetes, age of patients, age at onset of diabetes, body mass index, hemoglobin A1c level, blood pressure, and complications were noted.

Results:

The mean age of male and female patients was 54.93 and 54.25 years; 57.6% were males. The mean age of onset and mean duration of diabetes were 43.91 and 13.4 years, respectively. The proportion of retinopathy was 36.4%. Grades of retinopathy were: Mild 57.5%, moderate 19.9%, severe nonproliferative 11%, and proliferative retinopathy 11.6%; 7.2% of patients had maculopathy. Retinopathy was significantly associated with older age, younger age at onset, longer duration of disease, poorly controlled blood sugar, hypertension, insulin use; the presence of neuropathy and nephropathy appeared as a significant risk. Younger age at onset, longer duration, and insulin use appeared as the strongest predictors for diabetic retinopathy.

Conclusions:

More than a third (36.4%) of the diabetic patients attending a diabetic center had retinopathy. The control of the risk factors may reduce both prevalence and consequences of retinopathy.

The prevalence of and major risk factors associated with diabetic retinopathy in Gegharkunik province of Armenia: cross-sectional study

Background

Diabetic retinopathy (DR) is one of the leading causes of blindness in adults in industrialized countries and the emerging cause of blindness in developing countries. The objective of this study was to describe the prevalence of DR and risk factors associated with it among diabetic patients.

Methods

The analytical cross-sectional survey and eye screenings were carried out among 625 diabetic patients from urban and rural areas of Gegharkunik region. DR was assessed by dilated ophthalmoscopy and defined based on the WHO International Classification of Diseases. The survey instrument, included questions about demographics, disease history, health status, medication use and healthy lifestyle. Descriptive statistics and logistic regression were used to analyze the data.

Results

The prevalence of DR in the sample was 36.2%. A total of 90.2% of patients with DR had non-proliferative, while 9.8% had proliferative DR. In bivariate analysis, age, diabetes duration, being under insulin treatment, blood glucose level, having non-communicable diseases were significantly associated with DR. In the adjusted analysis being under insulin treatment (OR = 3.24; 95% CI: 1.56–6.75), diabetes duration (OR = 1.23; 95% CI: 1.16–1.31) and age (OR = 1.05; 95% CI: 1.02–1.08) were independently associated with DR.

Conclusion

Earlier diagnosis of diabetes and DR can help to control some of these factors and prevent further complications and vision loss. Population-based educational programs on diabetes and diabetic retinopathy and continuous medical education on diabetes management can improve diabetes care and self-management and prevent eye complications.

Iranian risk model as a predictive tool for retinopathy in patients with type 2 diabetes

OBJECTIVE

Diabetic retinopathy (DR) is the leading cause of blindness in patients with type 1 or type 2 diabetes. The gold standard for the detection of DR requires expensive equipment. This study was undertaken to develop a simple and practical scoring system to predict the probability of DR.

METHODS

A total of 1782 patients who had first-degree relatives with type II diabetes were selected. Eye examinations were performed by an expert ophthalmologist. Biochemical and anthropometric predictors of DR were measured. Logistic regression was used to develop a statistical model that can be used to predict DR. Goodness of fit was examined using the Hosmer-Lemeshow test and the area under the receiver operating characteristic (ROC) curve.

RESULTS

The risk model demonstrated good calibration and discrimination (ROC area=0.76) in the validation sample. Factors associated with DR in our model were duration of diabetes (odds ratio [OR]=2.14, confidence interval [CI] 95%=1.87 to 2.45); glycated hemoglobin (A1C) (OR=1.21, CI 95%=1.13 to 1.30); fasting plasma glucose (OR=1.83, CI 95%=1.28 to 2.62); systolic blood pressure (OR=1.01, CI 95%= 1.00 to 1.02); and proteinuria (OR=1.37, CI 95%=1.01 to 1.85). The only factor that had a protective effect against DR were body mass index and education level (OR=0.95, CI 95%=0.92 to 0.98).

CONCLUSIONS

The good performance of our risk model suggests that it may be a useful risk-prediction tool for DR. It consisted of the positive predictors like A1C, diabetes duration, sex (male), fasting plasma glucose, systolic blood pressure and proteinuria, as well as negative risk factors like body mass index and education level.

High HbA1c level was the most important factor associated with prevalence of diabetic retinopathy in Taiwanese type II diabetic patients with a fixed duration

BACKGROUND

To identify the prevalence and related risk factors for diabetic retinopathy (DR) in non-insulin dependent diabetes in Taiwan.

METHODS

A retrospective review of type II diabetic patients in the Diabetes Shared Care System database of our Hospital enrolled from 2002 to 2009. A retinopathy severity score was assigned according to fundus examination by indirect ophthalmoscopy or binocular biomicroscopy.

RESULTS

Data was collected on 901 subjects, 497 males and 404 females. Of these, 230 (25.53 %) had DR at enrolment. Compared with patients without DR, those with DR were more likely to be female (p = 0.03) or have higher HbA1c (p < 0.001), longer duration of diabetes (p < 0.001), hypertension (p < 0.001), higher systolic blood pressure (p < 0.001), higher diastolic blood pressure (p = 0.05), as well as impaired renal function (p = 0.001). In subgroup analysis stratified by diabetes duration, HbA1c was the most consistent independent risk factor associated to the prevalence of DR. Higher systolic blood pressure and female sex were significantly independent risk factors only in patients with a duration of diabetes < 4 years. On the contrary, old onset age showed a protective effect against DR only in those with a disease duration > 8 years.

CONCLUSIONS

High HbA1c level was the most important factor associated with prevalence of DR in Taiwanese type II DM patients with a fixed duration.

Prevalence of diabetic retinopathy in various ethnic groups: a worldwide perspective

The alarming rise in diabetes prevalence is a global public health and economic problem. Diabetic retinopathy is the most common complication of diabetes and the leading cause of blindness among working-age populations in the Western world. Screening and prompt treatment of diabetic retinopathy are not top priorities in many regions of the world, because the impacts of other causes of preventable blindness remain an issue. Ethnicity is a complex, independent risk factor for diabetic retinopathy. Observations from white populations cannot be extrapolated fully to other ethnic groups. The prevalence of diabetic retinopathy, sight-threatening diabetic retinopathy, and clinically significant macular edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the white population. Although all ethnic groups are susceptible to the established risk factors of diabetic retinopathy-such as length of exposure and severity of hyperglycemia, hypertension, and hyperlipidemia-ethnic-specific risk factors also may influence these rates. Such risk factors may include differential susceptibility to conventional risk factors, insulin resistance, differences in anthropometric measurements, truncal obesity, urbanization, variations in access to healthcare systems, genetic susceptibility, and epigenetics. The rates of nonproliferative diabetic retinopathy appear to be declining in the United States, supporting the observation that better medical management of diabetes and prompt treatment of sight-threatening diabetic retinopathy substantially improve the long-term diabetic retinopathy incidence; studies from other parts of the world are limited and do not mirror this finding, however. We examine the ethnicity and region-based prevalence of diabetic retinopathy around the world and highlight the need to reinforce ethnicity-based screening and treatment thresholds in diabetic retinopathy.

Evaluation of resistive index by color Doppler imaging of orbital arteries in type II diabetes mellitus patients with microalbuminuria

OBJECTIVE

Resistive index (RI) is an indirect measurement of blood flow resistance that can be used to evaluate vascular damage in ophthalmologic diseases. The purpose of this study was to evaluate the association between RI values of orbital arteries by using the color Doppler imaging (CDI) in type II diabetes mellitus (DM) patients with microalbuminuria.

PATIENTS AND METHODS

We evaluated 91 type II DM patients with microalbuminuria and 27 healthy subjects. The DM patients with microalbuminuria were grouped into two: group 1 consisted of patients with retinopathy (n = 51) and group 2 consisted of patients without retinopathy (n = 40). Healthy subjects constituted group 3 (n = 27). The mean RI values of ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery (PCA) were measured using CDI.

RESULTS

Compared to diabetic group 2, group 1 had significantly higher mean RIs of OA, CRA, PCA, and HbA1c levels (p < 0.001 for all). Besides, there were no statistical differences in mean RIs of OA, CRA, and PCA between the control group and group 2 (p = 1.0; p = 0.44; p = 0.67, respectively). Mean RIs of OA and PCA were significantly correlated with age in group 1 (r = 0.549, p < 0.001; r = 0.407, p = 0.003, respectively). Mean RI of CRA was significantly correlated with the duration of diabetes and age in group 1 (r = 0.296, p = 0.035; r = 0.486, p < 0.001, respectively).

CONCLUSION

Our study indicates that RI might be a useful marker for early diagnosis and follow-up of diabetic retinopathy, and orbital RI assessment would be beneficial for diabetic patients with retinopathy.

Prevalence of eye diseases in South Korea: data from the Korea National Health and Nutrition Examination Survey 2008-2009

PURPOSE

The aim of this study is to report on preliminary data regarding the prevalence of major eye diseases in Korea.

METHODS

We obtained data from the Korea National Health and Nutrition Examination Survey, a nation-wide cross-sectional survey and examinations of the non-institutionalized civilian population in South Korea (n = 14,606), conducted from July 2008 to December 2009. Field survey teams included an ophthalmologist, nurses, and interviewers, traveled with a mobile examination unit and performed interviews and ophthalmologic examinations.

RESULTS

The prevalence of visual impairment, myopia, hyperopia and astigmatism in participants over 5 years of age was 0.4 ± 0.1%, 53.7 ± 0.6%, 10.7 ± 0.4%, and 58.0 ± 0.6%, respectively. The prevalence of strabismus and blepharoptosis in participants over 3 years of age was 1.5 ± 0.1% and 11.0 ± 0.8%, respectively. In participants over 40 years of age, the prevalence of cataract, pterygium, early and late age-related macular degeneration, diabetic retinopathy and glaucoma was 40.2 ± 1.3%, 8.9 ± 0.5%, 5.1 ± 0.3%, 0.5 ± 0.1%, 13.4 ± 1.5%, and 2.1 ± 0.2%, respectively.

CONCLUSIONS

This is the first nation-wide epidemiologic study conducted in South Korea for assessment of the prevalence of eye diseases by both the Korean Ophthalmologic Society and the Korea Center for Disease Control and Prevention. This study will provide preliminary information for use in further investigation, prevention, and management of eye diseases in Korea.

Use of eye care services among diabetic patients in urban and rural China

OBJECTIVE

To assess the use of eye care and its predictors among diabetic patients in China.

DESIGN

Cross-sectional, clinic-based study.

PARTICIPANTS

Diabetic patients 18 years of age or older were recruited consecutively from an urban tertiary and community hospitals and from a rural clinic in Guangdong, China.

METHODS

Information obtained by questionnaire and chart review included: demographic and socioeconomic status, knowledge about diabetic retinopathy (DR), and ocular and medical history.

MAIN OUTCOME MEASURES

Self-reported or chart history of an eye examination ever or within the preceding 12 months.

RESULTS

The participation rate among 889 eligible subjects was 92.7%. Among 824 participants (mean age, 62.6+/-12.9 years; 58.8% female), 550 (66.7%) had not been examined in the last year as recommended by the American Academy of Ophthalmology, and 356 (43.2%) had never been examined. For the rural hospital, these figures were 81.1% and 68.7%, respectively. In regression analyses, factors associated with having an eye examination in the last year were: attendance at urban hospitals (odds ratio [OR], 3.46 [P<0.001] and 1.76 [P = 0.021] for the tertiary and community hospitals, respectively, compared with the rural clinic), higher DR knowledge score (OR, 1.24; P = 0.001), greater concern about vision loss (OR, 1.22; P = 0.007), and recommendation of regular eye examinations by the provider (OR, 2.36; P = 0.011). Predictors of ever having an eye examination were similar. Monthly income and health insurance status were not predictive of being examined.

CONCLUSIONS

These results suggest that the low proportion of diabetic receiving recommended annual eye examinations in China may be improved through patient and physician education.

Microaneurysm number and distribution in the macula of Chinese type 2 diabetics with early diabetic retinopathy: a population-based study in Kinmen, Taiwan

To explore the number and distribution of microaneurysms (MA) in the macula of type 2 diabetics in Kinmen, Taiwan and associated risks for early diabetic retinopathy (DR). A baseline mass screening extracts 971 type 2 diabetics between 1991 and 1993 and follow-up eye screening at 1999 was then done. Number of MA was counted and associated systemic factors collected from a centered 45 degrees color fundus photograph of dilated eyes of type 2 diabetics (Topcon-NW5). Thirty-three (6.2%, n = 527) had MA retinopathy. Those with one eye involved (n = 26) had two mean MA; those with bilateral involvement (n = 7) had four mean per eye. Most MA were located temporally (mean MA = 0.79), then superiorly (mean = 0.58), inferiorly (mean = 0.46) and nasal (mean = 0.28). MA occurred at the 6,000-microm outermost ring (mean = 1.51), then the 3,000-microm ring (mean = 0.35), the 1,500-microm ring (mean = 0.26) and center 500 microm circle (mean = 0.01). After adjusting for confounding factors, early DR with MA was associated with longer duration of type 2 diabetes [odds ratios (OR) = 1.10, 95% confidence interval (CI) 1.00-1.21], higher glycosylated hemoglobin (OR = 1.36, 95%CI 1.11-1.66) and wider waist circumference (OR = 1.04, 95%CI 1.01-1.07). Our photograph grading system suggests that MA number and distribution at the macula may reflect severity of early DR and is a valid tool for predicting the progression of DR. Identifying those factors associated with MA only DR is important in developing prevention strategies for this early microvascular complication of type 2 diabetes.

Prevalence of diabetic retinopathy in Tehran province: a population-based study

Background

To determine the prevalence and characteristics of diabetic retinopathy (DR) among Iranian patients with diabetes.

Methods

Design: population-based cross-sectional study.

Participants: patients with diabetes aged 25 to 64 years in Tehran province, Iran. This survey was conducted from April to October 2007. The study sample was derived from the first national survey of risk factors for non-communicable disease. Diabetes mellitus was defined as a fasting plasma glucose of ≥ 7.0 mmol/l (126 mg/dl) or more, use of diabetic medications, or a physician's diagnosis of diabetes. All patients known to have diabetes underwent an eye examination by bio-microscope and indirect ophthalmoscope to check for any signs of DR through dilated pupils by + 78 lens. Participants were also interviewed and examined to determine their demographic characteristics, medical conditions and the regularity of their eye visits.

Results

Among 7989 screened patients, 759 (9.5%) had diabetes. Of them, 639 patients (84.2%) underwent eye examination. Five patients (0.7%) with media opacity were excluded. Of 634 examined patients with diabetes, 240 had some degree of diabetic retinopathy, and the overall standardized prevalence of any retinopathy was 37.0% (95% CI: 33.2-40.8), including 27.3% (95% CI: 23.7-30.8) (n = 175) with non-proliferative and 9.6% (95% CI: 7.3-11.9) (n = 65) with proliferative diabetic retinopathy. Clinically significant macular edema and vision-threatening retinopathy were detected in 5.8% (95% CI: 4.0-7.7) (n = 38) and 14.0% (95% CI: 11.3-16.7) (n = 95) of patients, respectively. Only 143 patients (22.6%) with diabetes had a history of regular eye examination.

Conclusion

This study demonstrated a high prevalence and poor control of DR in Tehran province. This suggests the need for adequate prevention and treatment in patients with diabetes.

Hypoglycemic effect of Chlorella vulgaris intake in type 2 diabetic Goto-Kakizaki and normal Wistar rats

The aim of this study was to examine the hypoglycemic effect of chlorella in 6 week-old type 2 diabetic Goto-Kakizaki (GK, n=30) rats and 6 week-old normal Wistar (n=30) rats. Animals were randomly assigned to 3 groups respectively, and were fed three different experimental diets containing 0%, 3% or 5% (w/w) chlorella for 8 weeks. In diabetic GK rats, the insulinogenic-indices were not significantly different among the groups. The concentrations of fasting plasma glucagon and hepatic triglyceride, and the insulin/glucagon ratios of the GK-3% chlorella and GK-5% chlorella groups were significantly lower than those of the GK-control group. The HOMA-index and the concentrations of fasting blood glucose and plasma insulin of the GK-3% chlorella and GK-5% chlorella groups were slightly lower than those of the GK-control group. In normal Wistar rats, the insulinogenic-indices were not significantly different among the normal groups, but that of the Wistar-5% chlorella group was slightly higher than the other groups. The concentrations of fasting blood glucose and plasma insulin, and the HOMA-index of the Wistar-5% chlorella group were a little higher, and the fasting plasma glucagon concentration and the insulin/glucagon ratio of the Wistar-5% chlorella group were significantly higher than those of the Wistar-control and Wistar-3% chlorella groups. In conclusion, this study shows that the glucose-stimulated insulin secretion was not affected by the intake of chlorella, which could be beneficial, however, in improving insulin sensitivity in type 2 diabetic GK and normal Wistar rats.

Diabetic Retinopathy in Diabetics Referred to a Tertiary Centre from a Nationwide Screening Programme

Introduction: The aim of the study was to describe the prevalence and risk factors for diabetic retinopathy in a multi-ethnic diabetic patient cohort referred for retinal evaluation from a nationwide diabetic retinopathy screening programme in Singapore. Materials and Methods: Seven hundred and forty-two patients, aged 21 to 95, referred for suspected diabetic retinopathy on annual one-field non-mydriatic 45 degree retinal photographs (Topcon TRC-NW6, Topcon Corporation, Tokyo, Japan) from primary care to the Singapore National Eye Centre diabetic retinopathy clinic were included. The photographs had been interpreted by 24 trained family physicians accredited every 2 years with a training programme. Patients underwent a standardised interview and examination. Fundi were examined with indirect ophthalmoscopy by 2 examiners. Presence and severity of diabetic retinopathy was graded into none, mild, moderate, severe, very severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. Macular oedema and clinically significant macular oedema were also graded. Results: Ninety-nine per cent of patients were type 2 diabetics. The prevalence of diabetic retinopathy was 38.1%, visionthreatening retinopathy was 11.8% and macular oedema was 6.9%. There were no racial differences. Significant predictors of any retinopathy were longer duration of diabetes, lower body mass index, being on treatment for hypertension, hypercholesterolaemia and use of diabetic medication. Predictors for vision-threatening retinopathy were younger age, longer duration of diabetes and lower body mass index. Conclusions: The use of one-field non-mydriatic 45 degree photography as a screening tool for diabetic retinopathy resulted in a cohort of which 38.1% had diabetic retinopathy. Risk factors for diabetic retinopathy of this cohort are also presented. Key words: Diabetic retinopathy, Epidemiology, Ethnology, Singapore, Screening

Economic evaluation of screening for diabetic retinopathy among Chinese type 2 diabetics: a community-based study in Kinmen, Taiwan

BACKGROUND

This community-based study conducted in Kinmen aimed to discover whether screening for diabetic retinopathy (DR) among Chinese with type 2 diabetes was economically feasible and clinically effective.

METHODS

A total of 971 community-dwelling adults previously diagnosed with type 2 diabetes in 1991-1993 underwent DR screening in 1999-2002 by a panel of ophthalmologists, who used on-site indirect ophthalmoscopy and 45-degree color fundus retinal photographs. Economic evaluation included estimates for cost effectiveness and the cost utility of screening for DR.

RESULTS

For each DR case, screening efficacy and utility decreased, while cost increased with the length of the screening interval. The cost per sight year gained in the annual screening, biennial screening, 3-year screening, 4-year screening, 5-year screening, and control groups were New Taiwan dollars (NT dollars) 20962, NT dollars 24990, NT dollars 30847, NT dollars 37435, NT dollars 44449, and NT dollars 83411, respectively. The cost per quality-adjusted life year gained by the annual screening, biennial screening, 3-year screening, 4-year screening, 5-year screening, and control groups were NT dollars 21924, NT dollars 25319, NT dollars 30098, NT dollars 35106, NT dollars 40037, and NT dollars 61542, respectively. Threshold values indicate that the screening programs are highly sensitive to screening cost in the plausible range.

CONCLUSION

Screening for DR is both medically and economically worthwhile. Annual screening for DR among Chinese with type 2 diabetes should be conducted. Prevention programs aimed at improving eye care for patients with type 2 diabetes result in both substantial federal budgetary savings and highly cost-effective health care.

Risk Factors for Diabetic Retinopathy among Jordanian Diabetics

PURPOSE

To identify the risk factors associated with diabetic retinopathy among diabetic patients at Jordan University Hospital.

METHODS

A total of 986 patients with diabetes mellitus were assessed at Jordan University Hospital. The assessment included detailed relevant history, complete medical and ophthalmic evaluation.

RESULTS

Out of the 1961 eye examined, 64.1 percent had one form of diabetic retinopathy; 54.8 percent had nonproliferative diabetic retinopathy (NPDR), 9.3 percent had proliferative diabetic retinopathy (PDR) and 30.8 percent had maculopathy. Of all participants, 23.5 percent had combined NPDR and maculopathy while 7.6 percent had PDR and maculopathy. Using logistic regression analysis it was shown that old age group, long duration of diabetes, poor glycemic control, uncontrolled blood pressure and the presence of nephropathy were significantly associated with diabetic retinopathy. The incidence of maculopathy was significantly associated with the presence of hypertension, protienuria and high cholesterol level.

CONCLUSION

The challenge for the primary care physician and diabetologist is to attain excellent glycemic control, aggressive control of blood pressure and normalization of blood lipid in order to reduce the risk of blindness and lessen the burden from diabetic retinopathy.

Colour Doppler ultrasound evaluation of orbital vessels in diabetic retinopathy

The aim of this study was to determine the role of colour Doppler imaging in the retrobulbar vascular circulation in diabetic retinopathy (DR). Maximum (V(max)), end-diastolic (V(min)) and average (V(mean)) velocities of blood flows and pulsatility index and resistivity index (RI) in central retinal artery (CRA), short branches of posterior ciliary artery (PCA) and ophthalmic artery of the 65 diabetic and 22 control eyes were measured. The CRA V(max) level in the control group was significantly higher than in DR groups. The CRA V(mean) level was also significantly higher in the control group than in the mild nonproliferative diabetic retinopathy (NPDR) and the moderate NPDR groups. The CRA RI value was significantly higher in the control group than in the nonretinopathy group. The CRA V(min) and the ophthalmic artery RI values were found significantly higher in the nonretinopathy group than in the moderate NPDR group. There were significant decreases in the some CRA and PCA values as glycated haemoglobin (HbA1c) levels increase in diabetic group. There was a positive correlation between the duration of diabetes and HbA1c levels. This study showed the presence of some dynamic circulatory alterations in the nonretinopathy group with diabetes and DR groups. It was also shown that there is a negative correlation between HbA1c and some orbital vascular velocities.

[Epidemiology of diabetic retinopathy in Lebanon]

AIMS

To assess the prevalence of diabetic retinopathy, evaluate risk factors underlying its development, and assess the epidemiological characteristics of documented diabetes in the Lebanese population.

PATIENTS AND METHOD

The population-based study was conducted in three regions in Lebanon from January 2nd 2000 until June 30th 2000. The study group comprised 112 known diabetic patients who had previously been identified among 4,063 randomly selected individuals. All known diabetic patients underwent an interview, a physical examination, and a thorough retinal examination that included evaluation for the absence or presence of diabetic retinopathy. Retinal examination was performed by an ophthalmologist using direct and indirect ophthalmoscopy through dilated pupils. Several risk factors were then evaluated in order to delineate those related to occurrence of diabetic retinopathy.

RESULTS

The prevalence of known diabetes was 2.95%. Of the 120 known diabetic patients, 112 accepted to be examined. The sex ratio (m:f) was 1.43, the mean patient age was 60.98 years, the mean age at onset of diabetes was 51.75 years, and the mean duration of diabetes was 9.19 years. Type 1 diabetes was found in 1.8% of the patients, whereas 98.2% had type 2 diabetes. Diabetic retinopathy was detected in 19 patients (16.96%). Duration of diabetes, frequency of fundoscopic surveillance, and altered vision were found to be significantly related to the occurrence of diabetic retinopathy.

CONCLUSION

In our study, diabetic retinopathy was found in 16.96% of known diabetic patients, a lower rate than in most of other countries. Most of the diabetic patients (84.82%) were aware that diabetes causes ocular disease, yet only a few (17.85%) were under regular fundoscopic surveillance.

A community-based epidemiologic study of gender differences in the relationship between insulin resistance/beta-cell dysfunction and diabetic retinopathy among type 2 diabetic patients in Kinmen, Taiwan

PURPOSE

The purpose of this study was to explore whether there were gender differences in the relation of insulin resistance and beta-cell dysfunction to diabetic retinopathy among type 2 diabetic patients.

METHODS

From 1999 to 2002, a screening regimen for diabetic retinopathy was performed by a panel of ophthalmologists using ophthalmoscopy and 45-degree color fundus photography to examine the fundus in a total of 971 type 2 diabetic patients examined between 1991 and 1993 in Kinmen, Taiwan. Seven hundred and twenty-five type 2 diabetic patients (301 males and 424 females) attended ophthalmological fundus checkup.

RESULTS

The response rate in males and females was 71.3 and 77.2%. The proportion of diabetic retinopathy at the first eye screening was 16.3% in males and 20.1% in females. From the multiple logistic regression, the type of diabetes (known cases vs. new cases) was a significant factor of diabetic retinopathy in both males (OR = 3.65, 95% CI: 1.59-8.37) and females (OR = 3.66, 95% CI: 2.01-6.70). Diabetic retinopathy was also strongly affected by the homeostasis model assessment of insulin resistance (HOMA IR) and homeostasis model assessment of beta-cell dysfunction (HOMA beta-cell) (p < 0.0001 for trend test). In males, those who were in the 2nd quartile, 3rd quartile, and 4th quartile of HOMA IR had 4.87 times (95% CI: 1.18-20.11), 6.83 times (95% CI: 1.91-24.46), and 10.15 times (95% CI: 2.42-42.56) the risk for diabetic retinopathy as compared to those in the 1st quartile. There was a reduced risk for diabetic retinopathy in relation to HOMA beta-cell for the 2nd quartile, 3rd quartile, and 4th quartile of 86% (95% CI: 37-97%), 95% (95% CI: 77-99%), and 96% (95% CI: 78-99%) as compared to that in the 1st quartile. Only the 4th quartile had a significant risk (OR = 2.62, 95% CI: 1.17-5.86) for diabetic retinopathy as compared to that in the 1st quartile in females. The reduced risk for diabetic retinopathy found in relation to HOMA beta-cell for the 3rd and 4th quartiles were 66% (95% CI: 6-88%) and 66% (95% CI: 10-87%) as compared to that in the 1st quartile.

CONCLUSIONS

Gender differences in the relationship between insulin resistance/beta-cell dysfunction and diabetic retinopathy were demonstrated in type 2 diabetic patients.

The epidemiology of age related eye diseases in Asia

In the past decade, several large population based studies have provided new information on the prevalence of visual impairment and the major age related eye diseases in Asia. These include epidemiological studies from India, Taiwan, Mongolia, Singapore, and Japan. In particular, the epidemiology of refractive errors and glaucoma has been well characterised, providing insights not only into the public health implications of these conditions, but also into anatomical changes of the eye with ageing. In contrast, there are few well conducted population based studies on diabetic retinopathy and age related macular degeneration in Asia, two conditions that are likely to be important causes of blindness in the future.

Treatment of type 2 diabetes mellitus in a primary care setting in Taiwan: comparison with secondary/tertiary care

BACKGROUND

This study investigated the status of diabetes control and management in patients treated in a primary healthcare setting and compared the results with data previously obtained for secondary/tertiary care patients in Taiwan.

METHODS

This study was conducted at 51 primary healthcare stations randomly selected island-wide in Taiwan in 2001. A total of 1302 type 2 diabetes patients who had been followed-up for more than 1 year were included. Blood was collected for centralized HbA1c assay. The remaining data and information were collected by review of medical records and patient interview.

RESULTS

Compared with the results of a previous study on patients treated in a secondary/tertiary care setting, a significantly smaller percentage of primary care patients were receiving insulin therapy. Primary care patients also had a shorter duration of diabetes, a higher HbA1c level, better blood pressure control and a lower prevalence of complications. The proportion of patients achieving optimal control of glycemia and blood pressure was low. Patients aged < 65 years had a significantly shorter duration of diabetes, poorer diabetes control and better blood pressure control than elderly patients aged > or = 65 years. Primary care patients aged > or = 65 years had a significantly higher frequency of stroke than those aged < 65 years. The elderly group of secondary/tertiary care patients had a significantly higher frequency of coronary heart disease and stroke. Duration of diabetes and hypertension were the leading risk factors for complications in diabetes patients treated in both primary and secondary/tertiary care settings.

CONCLUSION

Diabetes control was poorer in primary care than in secondary/tertiary care patients, but control of blood pressure was better in primary care patients. The shorter duration of diabetes and better control of blood pressure in primary care patients and in patients aged < 65 years compared with their elderly counterparts might be related to a lower prevalence of complications.

Population-Based Study of Nonproliferative Diabetic Retinopathy Among Type 2 Diabetic Patients in Kinmen, Taiwan

PURPOSE

This study was conducted to assess the prevalence and associated factors of nonproliferative diabetic retinopathy among type 2 diabetic patients in Kinmen, Taiwan.

METHODS

From 1991 to 1993, 971 type 2 diabetic patients in Kinmen underwent diabetic retinopathy screening performed by a panel of ophthalmologists using indirect ophthalmoscopy and 45 degrees color fundus retinal photographs.

RESULTS

Of the 971 patients screened in 1991-1993, 578 (59.5%) were examined for this study. Diabetic retinopathy was diagnosed in 127 patients (22.0%), including nonproliferative diabetic retinopathy in 13.3%, proliferative diabetic retinopathy in 1.4%, legal blindness in 1.4%, and ungradable diabetic retinopathy in 5.9%. Significant associated factors of nonproliferative diabetic retinopathy based on multiple logistic regression analysis were fasting plasma glucose (FPG) at baseline [> or =126 mg/dl vs. <126 mg/dl; odds ratio (OR) = 2.89; 95% confidence interval (CI), 1.01-9.09], 2-h postload at baseline (> or =200 vs. <200 mg/dl; OR = 1.48; 95% CI, 1.09-2.07); HbA1c at follow-up (> or =7% vs. <7%; OR = 6.54; 95% CI, 3.01-14.20), duration of diabetes (> or =15 years vs. <10 years; OR = 6.72; 95% CI, 2.13-21.18), and incremental systolic blood pressure between baseline and follow-up (OR = 1.02; 95% CI, 1.00-1.04).

CONCLUSIONS

In addition to the longer duration of type 2 diabetes, FPG at baseline, poorly controlled glucose concentration, and altered blood pressure may increase the risk of nonproliferative diabetic retinopathy in type 2 diabetic patients.

Gender differences in the utilisation of optometric services in Victoria

Medicare and population data demonstrate clear gender differences in utilisation of health services. There are three broad hypotheses that may explain different utilisation rates of health services by gender: differences in access, differences in incidence and differences in attitudes in seeking health care between the genders. Men are 28 per cent less likely than women to see an optometrist in Victoria. Both women's and men's utilisation of optometric services in Victoria increase with age but there are clear gender differences apparent at every stage of life after childhood. These utilisation rates between genders are tested against incidence rates between genders for eye conditions. There are few noted gender differences apparent in the incidence or prevalence of ocular conditions. The data on the incidence of health conditions often has limitations, either in measurement tools or in differences in incidence between genders. These limitations are not as evident in eye care incidence data. Access and incidence differences do not adequately explain the differences in optometric service utilisation rates. This promotes the hypothesis that attitudinal differences in seeking health care between men and women are significant.

Epidemiology of diabetic retinopathy and macular oedema: a systematic review

AIMS

To systematically review the literature on the prevalence and incidence of diabetic retinopathy (DR) and macular oedema (MO).

METHODS

A search of the bibliographic databases (Medline, Embase, CINAHL) was conducted up to October 2001. Selected relevant studies were scrutinized and included in the review.

RESULTS

A total of 359 studies were included. The studies were reported in nearly 100 different journals and in over 50 countries. The majority of the studies were US-based, with large studies such as the Wisconsin Epidemiologic Study of Diabetic Retinopathy dominating the literature. The studies were quite dated and highly heterogeneous in nature in terms of patient selection with variable inclusion criteria (age range, gender, diabetes duration and type, ethnicity, comorbidity, and DR status, assessment, and classification).

CONCLUSIONS

There are inconsistencies between epidemiological studies, and differences in study methods may contribute to conflicting reports of prevalence and incidence of DR and MO in diabetic populations. As new therapies for DR and its associated complications emerge, the need to capture and monitor new epidemiological data becomes increasingly important to be able to assess the impact and effectiveness of these therapies. Robust, longitudinal capture of patient data is, therefore, essential to evaluate the impact of current practice on the epidemiology of diabetic eye complications.