Prevalence and risk factors for diabetic retinopathy in rural India. Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III (SN-DREAMS III), report no 2

The profile of sight-threatening diabetic retinopathy in patients attending a specialist eye clinic in Hangzhou, China

Background/aims

To examine the profile of diabetic retinopathy, awareness and self-help in patients attending a specialist eye clinic in Hangzhou, China.

Methods

A total of 199 consecutive patients with diabetes (mean age = 57 years, SD = 11) attending eye clinic at the School of Medicine, Zhejiang University, Hangzhou were examined in a cross-sectional study. Clinical/demographic data were obtained from patients' records. Fundus photographs obtained from each patient were graded using Early Treatment of Diabetic Retinopathy Study (ETDRS) criteria; severe non-proliferative, proliferative retinopathy and/or macular oedema (hard exudates/thickening around fovea) were classified as sight-threatening diabetic retinopathy (STDR). Optical coherence tomography was used to confirm the diagnosis of macular oedema. Data on knowledge/awareness about diabetes and self-help/lifestyle were collected using a structured questionnaire.

Results

STDR was found in 80% patients of whom 18% had visual acuity of ≤counting fingers in at least one eye. Male gender, longer diabetic duration and use of insulin were significantly associated with STDR (p ≤ 0.05). Of the total, 41% patients reported that they were attending for the first time. Of all the first-time attendees, 67% had STDR. Also of all the first-time attendees, 14% were unclear whether diabetes affected their eyes. Fifty-one per cent of patients who thought their diabetes was well controlled had fasting blood sugar ≥6.5 mmol/L (p < 0.001). Of the total, 65% patients reported not doing ≥4 hours/week of physical exercise.

Conclusions

The majority of patients with diabetes presented to this eye clinic suffered with late-stage retinopathy. Our results advocate the need to improve diabetic diagnosis, management and awareness and to set up eye screening for diabetics in Hangzhou, China.

Age of Onset of Diabetes and Its Comparison with Prevalence and Risk Factors for Diabetic Retinopathy in a Rural Population of India

AIM

To compare the age of onset of diabetes with the prevalence and risk factors of diabetic retinopathy (DR) in a rural population of India.

METHODS

This is a population-based study for which 1,190 people with diabetes were recruited from rural areas of the districts of Kanchipuram and Thiruvallur, Tamil Nadu, India. The fundi of all patients were photographed using a 45°, four-field stereoscopic digital fundus camera. The diagnosis of DR was based on the Klein classification of the Early Treatment Diabetic Retinopathy Study scale.

RESULTS

The prevalence of DR was 11.5% in individuals with known onset of diabetes (aged ≤40 years) compared to 10.0% in those with late onset. The risk factors for any DR in both groups included longer known duration of diabetes, use of insulin, and the presence of high systolic blood pressure and hypertension. In the group with known onset of diabetes at ≤40 years, older age (p < 0.0001) and male gender (p = 0.018) were the significant factors for DR. In the group with age of onset of diabetes at > 40 years, high diastolic pressure (p = 0.001), higher HbA1c (p < 0.0001), high microalbuminuria (p < 0.0001), and high macroalbuminuria (p < 0.008) were the significant risk factors for DR.

CONCLUSION

Control of risk factors in people with younger age of onset of diabetes may reduce both the prevalence and impact of retinopathy in rural populations.

Evaluation of multiple risk factors involved in the development of Diabetic Retinopathy

Objective:

To determine the role of hypertension, hyperlipidemia, smoking and positive family history of diabetes and hypertension in the development of diabetic retinopathy.

Methods:

This prospective cohort study was conducted at the Department of Chemical Pathology, Armed Forces Institute of Pathology, Rawalpindi over 2 years period from June 2014 to June 2016. One hundred consecutive diabetic patients with no signs of diabetic retinopathy and good glycemic control (HbA1c<6.5%) were registered by non-probability convenient sampling after taking written informed consent. They were evaluated for hypertension, hyperlipidemia and smoking status. These patients were then followed 6 monthly for 2 years to look for the development of diabetic retinopathy.

Results:

The mean age of the patients was 50.72±9.29 years and there were 57 (57%) male and 43 (43%) female patients. Majority (82%) of the patients had NIDDM. The mean duration of diabetes was 8.31±6.83 years. 11% of the patients were smoker, 37% were hypertensive, 6% had hyperlipidaemia, 62% had family history of diabetes and 30% had family history of hypertension. At the end of follow-up, 9 (9.0%) patients had diabetic retinopathy. The frequency of diabetic retinopathy increased with increasing age of the patient; however, the difference was statistically insignificant. A comparatively higher frequency of diabetic retinopathy was also seen in patients with IDDM and those with positive family history of diabetes and hypertension yet again, the difference was statistically insignificant. Also, no significant difference was noted among male and female genders and smokers vs. non-smoker. However, the frequency of diabetic retinopathy increased significantly with increasing duration of diabetes. It was also higher among those with hypertension and hyperlipidemia.

Conclusion:

Higher patient age (≥50 years), increasing duration of diabetes (≥20 years), insulin dependent diabetes mellitus, hypertension, hyperlipidemia, and positive family history of diabetes and hypertension were found to be associated with increased frequency of diabetic retinopathy.

Public health system integration of avoidable blindness screening and management, India

In India, 73 million people have diabetes and 3.5 million infants are born preterm. Without timely screening, there is a risk of visual loss due to diabetic retinopathy and retinopathy of prematurity in these two groups, respectively. Both conditions are emerging causes of visual impairment in India but there is no public health programme for screening or management. Pilot projects were initiated in 2014 to integrate the screening and management of these conditions into existing public health systems, particularly in rural communities and their referral networks. The World Health Organization's health systems framework was used to develop the projects and strategies were developed with all stakeholders, including the government. Both projects involved hub-and-spoke models of care units around medical schools. For diabetic retinopathy, screening was established at primary health-care facilities and treatment was provided at district hospitals. For retinopathy of prematurity, screening was integrated into sick newborn care units at the district level and treatment facilities were improved at the closest publically funded medical schools. In the first two years, there were substantial improvements in awareness, screening, treatment and partnership between stakeholders, and changes in public health policy. By March 2018, diabetic retinopathy screening was established at 50 facilities in 10 states and treatment had been improved at 10 hospitals, whereas retinopathy of prematurity screening was established at 16 sick newborn care units in district hospital in four states and treatment had been improved at six medical schools. Advocacy within state governments was critical to the success of the initiative.

Analysis of yield of retinal imaging in a rural diabetes eye care model

Purpose:

The aim of this study is to analyze the yield of retinal images obtained in a rural diabetes eye care model.

Methods:

An analysis of a sample of nonmydriatic fundus photography (NMFP) of posterior segment ophthalmic images, obtained by an indigenous equipment (3 nethra-Forus Royal), was done in a district-wide rural diabetic retinopathy (DR) screening program; a trained optometrist did the initial image grading. DR and diabetic macular edema (DME) were classified based on international DR and DME severity scale. The agreement between the optometrist and retina specialist was very good (κ = 0.932; standard error = 0.030; 95% confidence interval = 0.874–0.991).

Results:

Posterior segment images of 2000 eyes of 1000 people with diabetes mellitus (DM) were graded. The mean age of the participants was 55.7 ± 11.5 standard deviation years. Nearly 42% of the screened participants (n = 420/1000) needed referral. The most common referable posterior segment abnormality was DR (8.2%). The proportion of people with any form of DR was seen in 110/1225 eyes, and sight-threatening DR was seen in 35/1225 eyes. About 62% of posterior segment images were gradable. The reasons for ungradable posterior segment images (34%) were small pupil, unfocused/partially available field of images, and cataract.

Conclusion:

A NMFP model was able to detect referable posterior segment abnormalities in a rural diabetes eye care program. Reasons found for ungradability of images in the present study can be addressed while designing future DR screening programs in the rural areas.

Diabetic retinopathy screening programme utilising non-mydriatic fundus imaging in slum populations of New Delhi, India

OBJECTIVES

To develop and implement a community-based programme for screening of diabetic retinopathy (DR) in urban populations of Delhi.

METHODS

Known diabetics (KDs) aged 40 years and older were identified through house-to-house surveys, volunteers and publicity. All KDs were referred to DR screening camps organised locally where procedures included brief medical history, ocular examination and non-mydriatic fundus photography using portable handheld camera. Fundal images were graded on the spot by trained optometrists for DR. Patients with DR were referred to tertiary centre for management.

RESULTS

A total of 11 566 KDs were identified, of whom 9435 (81.6%) visited DR screening camps and 8432 (89.4%) had DR gradable images. DR was identified in 13.5% of subjects; 351 cases were mild NPDR, 567 moderate, 92 severe. Seventy-seven had PDR, and 49 had DME, and 2.7% of participants were blind (presenting visual acuity <3/60 in better eye). Non-use of lifestyle management, presence of systemic complications, BMI <18.5 kg/m² , disease duration of >5 years and uncontrolled diabetes were associated with increased odds of DR. All cases with DR were referred, and 420 (37%) successful referrals to base hospital were observed.

CONCLUSION

The programme of creating awareness about DR, identifying KDs and optometrist-led DR screening using non-mydriatic fundus camera based in slums was successful.

Diabetic Retinopathy in the Asia-Pacific

Diabetic retinopathy (DR), the most common complication of diabetes mellitus, is the leading cause of new cases of blindness in middle-aged and elderly in the Asia-Pacific. It has been estimated that 51% of all those with blindness due to DR globally (n = 424,400) and 56% of those with visual impairment due to DR (2.1 million) come from the Asia-Pacific. Prevalence of DR among those with diabetes ranged from 10% in India to 43% in Indonesia within the Asia-Pacific. Awareness of DR among persons with diabetes ranged from 28% to 84%. Most common modifiable risk factors for DR in the Asia-Pacific were hyperglycemia, blood pressure, dyslipidemia, and obesity. Implementation of systematic screening programs for DR and advancement in telemedicine screening methods have increased patient coverage and cost-effectiveness, though there are still numerous factors impeding screening uptake in the low-middle income regions of the Asia-Pacific. Management and treatment of DR in the Asia-Pacific is mainly limited to traditional laser retinopexy, but it is suboptimal despite new clinical approaches such as use of intravitreal anti.vascular endothelial growth factor and steroids due to limited resources. Further research and data are required to structure a more cost-effective public healthcare program and more awareness-building initiatives to increase the effectiveness of DR screening programs.

Need to improve awareness and treatment compliance in high-risk patients for diabetic complications in Nepal

OBJECTIVE/INTRODUCTION

It is known that knowledge, awareness, and practice influence diabetic control. We compared factors pertaining to healthy lifestyle (exercising, avoiding smoking), self-help (attending appointments, following treatment regimens), and diabetic awareness in high-risk patients for diabetic complications, specifically, those on insulin versus non-insulin treatment, and also those with a longer diabetic duration (≥5 years) versus a shorter duration.

METHODS

200 consecutive patients with type 2 diabetes (52.0±11.6 years) attending diabetic clinic at a referral hospital in Nepal were recruited. A structured questionnaire explored non-clinical parameters including age, gender, diabetic duration, awareness about diabetes control, self-help, and lifestyle. Clinical data were also measured: HbA1c, fasting blood sugar (FBS), blood pressure, and treatment type (insulin, diet/tablet).

RESULTS

A significantly higher proportion of patients on insulin (vs non-insulin) or with diabetic duration ≥5 years (vs <5 years) self-reported not doing regular exercise, forgetting to take medicine, and not knowing whether their diabetes was controlled (p≤0.005). HbA1c/FBS levels were significantly higher for patients on insulin or with a longer diabetic duration (p≤0.001). 92% of those on insulin (vs 31% on non-insulin) and 91% with diabetic duration ≥5 years (vs 28% of <5 years) self-reported to seeking medical help due to episodes of uncontrolled blood sugar in the last year (p<0.001).

CONCLUSION

Poor self-help/lifestyle and reduced knowledge/awareness about diabetic control was found in patients on insulin or with longer diabetic duration. This is a worrying finding as these patients are already at high risk for developing diabetic complications. The findings highlight need for targeting this more vulnerable group and provide more support/diabetic educational tools.

Assessment of visual morbidity amongst diabetic retinopathy at tertiary eye care center, Nepal: a cross-sectional descriptive study

BACKGROUND

Diabetic retinopathy (DR) is one of the leading causes of preventable blindness in low and middle income countries. In Nepal, there are less studies regarding DR and they too are limited around Kathmandu valley. This study was done to assess visual morbidity in patients with DR at a peripheral tertiary eye care center of Nepal.

METHODS

This was a prospective, hospital based, cross-sectional study in which all consecutive cases of DR were evaluated. DR was classified according to Early Treatment Diabetic Retinopathy Study Research Group - report no. 10 Table A5-1 (Modified Airlie House Classification). Data entry and analysis was done in an SPSS unit version 20. Wherever applicable, variables were set as 100 eyes.

RESULTS

Total number of patients included in this study was 50. Commonest age group was 50-69 yrs. (43/77 yrs.; min/max) comprising 80% of the total population (n = 50) and the predominant population was male (76%). Non proliferative diabetic retinopathy (NPDR) was found in 69%, proliferative diabetic retinopathy (PDR) in 31% and advanced diabetic eye disease (ADED) in 3% (n = 100).

CONCLUSIONS

All the stages of DR were present at significant proportions in this study, noteworthy was the percentage of PDR. This study shows an urgency to gather a national data on DR, raise awareness among diabetics and train effective man power at a local level to diagnose DR at an early stage.

Correlation of various serum biomarkers with the severity of diabetic retinopathy

Hyperglycemia induced inflammation and angiogenic factors are implicated as a contributor to the onset and progression of diabetic retinopathy (DR) in type 2 diabetes mellitus patients (T2DM). Tumor necrosis factor (TNF-alpha) and C-reactive protein (CRP) are inflammatory cytokines which induce retinal VEGF and are involved in the progression of proliferative diabetic retinopathy (PDR). Therefore the aim of the present study is to investigate the relationship between diabetic retinopathy and systemic inflammation in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

Patients with T2DM, with or without diabetic retinopathy were included in the study. Serum inflammatory cytokines, vascular growth factor were studied in different stages of DR.

RESULTS

Patients with T2DM with and without diabetic retinopathy were compared. Patients with diabetic retinopathy had increased serum levels of inflammatory cytokines CRP, TNF-alpha, as well as VEGF compared to serum levels of diabetic patients without retinopathy.

CONCLUSION

T2DM patients with retinopathy have higher levels of circulating inflammatory cytokines and VEGF compared to patients without retinopathy. These proinflammatory cytokines and angiogenic factors are involved in the progression of DR and proliferative diabetic retinopathy. The results showed the importance of inflammation and vascular endothelial growth factor in the progression of NPDR and PDR.

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

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

Delayed follow-up in patients with diabetic retinopathy in South India: Social factors and impact on disease progression

Purpose:

To identify social factors associated with delayed follow-up in South Indian patients with diabetic retinopathy (DR) and to study DR progression during the delayed follow-up period.

Materials and Methods:

In this cross-sectional study, 500 consecutive patients with DR returning after greater than twice the advised follow-up period were identified from a tertiary referral center in South India. A previously validated 19-item questionnaire was administered to study patients to assess causes for the follow-up delay. Patient demographics, DR status, and treatment plan were recorded at the study visit and the visit immediately before the delay. The eye with the most severe disease was included in the analysis.

Results:

Complete data were available for 491 (98.2%) patients. Among these, 248 (50.5%) cited “my eyes were okay at the time,” 201 (41.0%) cited “no attender to accompany me,” and 190 (38.6%) cited “financial cost” as causes of the follow-up delay. Those with vision-threatening DR (VTDR, n = 233) predominantly reported “financial cost” (47% vs. 32%, P = 0.001), whereas those with non-VTDR more frequently reported “my eyes were okay at the time” (58% vs. 42%, P = 0.001). Evidence of disease progression from non-VTDR to VTDR was seen in 67 (26%) patients. Almost 1/3^rd (29%) of patients who were previously advised regular examination required additional intervention.

Conclusion:

Many patient-level factors affect poor compliance with follow-up in DR, and these factors vary by disease severity. Targeting these barriers to care through patient education and clinic procedures may promote timely follow-up and better outcomes in these patients.

Prevalence of type 2 diabetes and its complications in India and economic costs to the nation

Diabetes, a major lifestyle disorder, has become a global burden, and the prevalence rates are rising steeply in developing economies. Rapid socioeconomic transition with urbanization and industrialization are the main causes for the global diabetes epidemic. Among developing economies, the highest increase in number of people with diabetes is in China followed by India. In India, the epidemic of diabetes continue to increase and is experiencing a shift in diabetes prevalence from urban to rural areas, the affluent to the less privileged and from older to younger people. Diabetes is a progressive disorder leading to complications, which are broadly divided into small vessel or microvascular disease and large vessel or macrovascular disease. Microvascular complications affect the inner part of the eye-the retina known as diabetic retinopathy, the kidney termed as diabetic nephropathy and the peripheral nerves termed as diabetic neuropathy. The macrovascular complications affect the heart, the brain and the peripheral arteries termed as cardiovascular disease, cerebrovascular disease and peripheral vascular disease, respectively. Given the lifelong expenditure associated with diabetes and its complications, individuals, families and the society are unable to cope with the economic, emotional and social disease burden due to diabetes. The economic burden of diabetes can be reduced by providing universal healthcare coverage, access to affordable medicines and early detection and treatment of the disorder. This emphasizes the need for a multi-prolonged strategy to minimize the burden of diabetes and its complications.

Effect of Almond Supplementation on Glycemia and Cardiovascular Risk Factors in Asian Indians in North India with Type 2 Diabetes Mellitus: A 24-Week Study

Background: Type 2 diabetes (T2D) statistics have reached menacing proportions in India. Appropriate dietary intervention, as part of healthy lifestyle, is imperative to curb further spread of this disease.

Objectives: This pre–post intervention study was conducted in New Delhi, India, to investigate the effects of daily consumption of almonds for 24 weeks in T2D subjects, specifically on measures of glycemia and cardiovascular disease (CVD) risk factors.

Methods and Study Design: In this study, the 24-week intervention period was preceded by a control diet and exercise run-in period of 3 weeks. Raw almonds (20% of energy intake) were provided to the patients for consumption along with diet and physical activity counseling. Patients were assessed for anthropometry, blood pressure, measures of glycemia (fasting blood glucose, glycosylated hemoglobin), lipids [total cholesterol (TC), triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, lipoprotein(a)], surrogate marker of atherosclerosis (Pulse wave velocity), and marker of inflammation (high sensitivity C-reactive protein [hs-CRP]) at baseline and after the intervention period.

Results: Statistically significant improvement in mean values for various parameters post intervention was as follows: waist circumference (P < 0.03), waist-to-height ratio (P < 0.005), TC (P < 0.002), serum triglycerides (P < 0.004), low-density lipoprotein cholesterol (P < 0.01), glycosylated hemoglobin (P < 0.04), and hs-CRP (P < 0.01). A trend toward improvement in pulse wave velocity (P < 0.06) was also observed.

Conclusion: The study findings illustrate that incorporation of almonds in a well-balanced healthy diet leads to multiple beneficial effects on glycemic and CVDs risk factors in Asian Indian patients with T2D.

Incidence of complications in young-onset diabetes: Comparing type 2 with type 1 (the young diab study)

BACKGROUND

There is little data on the incidence of diabetes complications in young onset type 1 diabetes (T1DM) and type 2 diabetes (T2DM) in non European populations.

METHODS

From a tertiary diabetes centre, Chennai, India, we recruited 108 T1DM (defined by abrupt onset of symptoms or diabetic ketoacidosis, absent insulin reserve requiring insulin treatment) and 90 T2DM participants (defined by absence of ketosis, good beta-cell reserve, and good response to oral agents) who were diagnosed between the ages of 10 and 25years, and without any evidence of diabetes complications at diagnosis. We estimated the incidence of various complications (median follow up of five years); retinopathy was defined by presence of at least one definite microaneurysm by retinal photography, nephropathy by urinary albumin excretion ⩾30μg/mg of creatinine, neuropathy by vibration perception threshold ⩾20V on biothesiometry, peripheral vascular disease by an ankle-brachial index <0.9, and ischemic heart disease (IHD) by history of myocardial infarction or coronary revascularization or Q waves on ECG or on drug treatment for IHD.

RESULTS

The mean ages at diagnosis of T1DM and T2DM participants were 17.1±4.2vs. 21.6±3.6years respectively. The incidence of various complications reported in numbers/1000 person years of follow up of T1DM and T2DM were: retinopathy 77.4vs. 78.0/1000 person years, nephropathy, 62.0vs. 58.8, neuropathy 7.8 vs. 13.9 and ischemic heart disease 1.2vs. 5.4. In Cox regression analysis, after adjustment for age, glycated hemoglobin, systolic blood pressure and serum cholesterol, T2DM participants had 2.11 times (95%CI: 1.27-3.51) higher risk of developing any diabetes complication, compared to T1DM.

CONCLUSIONS

Young-onset T2DM have a more aggressive disease course than T1DM.

Diabetic care initiatives to prevent blindness from diabetic retinopathy in India

It is estimated that 65 million (17%) of 382 million persons with diabetes mellitus (DM) globally reside in India. While globally 35% persons with DM have diabetic retinopathy (DR), this proportion is reportedly lower in India, other countries in South Asia and China. We reviewed published data from 2008 onwards from PubMed, which ascertained DR in population-based representative samples. We also reviewed the risk factors for DR, on awareness regarding eye complications and on accessing an eye examination. Thirteen research studies have reported on the prevalence of DR among persons with DM; this prevalence was lower than the global level in China, India, and Nepal. Eleven studies reported DR risk factors association. The duration of diabetes and level of glycemic control were universally acknowledged DR risk factors. We identified 7 studies in the Asia region that researched the level of awareness about diabetes eye complications and the practice of accessing an eye examination. Excepting 1 study in China, others reported a significant proportion being aware that diabetes leads to eye complications. But the awareness was not translated into a positive practice-most studies reported only 20-50% of the persons with diabetes actually having had their eyes examined. The present review highlights the observation that the risk factors for DR need an integrated diabetic care pathway where the eye care team has to work in close collaboration and partnership with a diabetic care team has to reduce the risk of blindness from DR.

Diabetic retinopathy: An epidemic at home and around the world

Prevention of blindness due to diabetic retinopathy (DR) requires effective screening strategies, for which eye care providers need to know the magnitude of the burden and the risk factors pertinent in their geographical location. It is estimated that around 72 million of the global adult population (around 8.2%) has diabetes and about one-fifth of all adults with diabetes lives in the South-East Asia. In India, around 65 million people have diabetes. As the global prevalence of diabetes increases, so will the number of people with diabetes-related complications, such as DR; nearly one-third of them are likely to develop this complication. This article reviews the present status of diabetes and DR in India, the current situation of DR services and the projections on the load of morbidity associated with retinopathy. The article compiles the Indian studies elucidating the risk factors for DR.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Microvasular and macrovascular complications in diabetes mellitus: Distinct or continuum?

Diabetes and related complications are associated with long-term damage and failure of various organ systems. The line of demarcation between the pathogenic mechanisms of microvascular and macrovascular complications of diabetes and differing responses to therapeutic interventions is blurred. Diabetes induces changes in the microvasculature, causing extracellular matrix protein synthesis, and capillary basement membrane thickening which are the pathognomic features of diabetic microangiopathy. These changes in conjunction with advanced glycation end products, oxidative stress, low grade inflammation, and neovascularization of vasa vasorum can lead to macrovascular complications. Hyperglycemia is the principal cause of microvasculopathy but also appears to play an important role in causation of macrovasculopathy. There is thought to be an intersection between micro and macro vascular complications, but the two disorders seem to be strongly interconnected, with micro vascular diseases promoting atherosclerosis through processes such as hypoxia and changes in vasa vasorum. It is thus imperative to understand whether microvascular complications distinctly precede macrovascular complications or do both of them progress simultaneously as a continuum. This will allow re-focusing on the clinical issues with a unifying perspective which can improve type 2 diabetes mellitus outcomes.

Telemedicine in diabetic retinopathy: Access to rural India

Diabetic retinopathy (DR) is a growing concern in India. The first step in management of DR is timely screening. With 10% prevalence in rural India, 11 million people are likely to have DR by the year 2030. With limited resources and skilled manpower, it will not be possible to have routine eye examination to identify and treat these patients on a regular basis. Telemedicine is a possible answer in these situations where patients could be remotely screened and appropriately advised. With the advent of several technological advances such as low cost hand-held nonmydriatic camera, increased capabilities of the smartphones to take external eye and retinal photographs coupled with improving broadband connectivity; teleophthalmology in the management of DR could be a reality in the not too distant future.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Prevalence of Diabetic Retinopathy and Vision Loss in the Beijing Eye Study: the Potential Role of the Cerebrospinal Fluid Pressure

In the Beijing Eye Study, a population-based study carried out in 2001, 2006, and 2011, prevalence of diabetic retinopathy (DR) was 2.9 ± 0.3 % (95 % confidence interval 2.3, 3.5) per individual in 2011. Correspondingly, only 1.1 % of blindness and 0.8 % of visual impairment were caused by DR in East Asia. As in other populations, prevalence, severity, and 10-year incidence of DR were associated with higher levels of HbA1c, higher blood glucose concentration, longer known duration of diabetes, lower educational level, and higher blood pressure. Interestingly, the presence, severity, and 10-year incidence of DR were additionally correlated with higher estimated cerebrospinal fluid pressure and shorter ocular length. Higher cerebrospinal fluid pressure may lead to higher retinal vein pressure and subsequently higher retinal capillary blood pressure increasing fluid and blood extravasation. Shorter axial length or hyperopia may be associated with higher intraocular concentration of cytokines. Aging of the society, improvements in medical infrastructure, and lifestyle changes may profoundly increase prevalence of, and burden by, DR in China in the future.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.