Prevalence of Diabetic Retinopathy in Urban Slums: The Aditya Jyot Diabetic Retinopathy in Urban Mumbai Slums Study—Report 2

Prevalence of diabetic retinopathy in patients with newly diagnosed type 2 diabetes: A systematic review and meta-analysis

AIMS

Type 2 diabetes mellitus (T2DM) can remain undiagnosed for many years, during which micro- and macro-vascular complications may develop. This study aimed to assess the worldwide prevalence of diabetic retinopathy (DR) in patients with newly diagnosed T2DM.

MATERIALS AND METHODS

We systematically searched electronic databases for relevant studies published from inception to 01 January 2022. Selected studies reported the prevalence of DR among patients with newly diagnosed T2DM, specifying the case definition used. Random-effects meta-analysis was used to derive the pooled prevalence. Subgroup and meta-regression analyses were used to investigate variations in the prevalence estimates in terms of available variables.

RESULTS

Data from 77 studies including 99,847 patients with newly diagnosed T2DM were included from 26 countries. The pooled prevalence of DR among patients with newly diagnosed T2DM was 13.1% (95% CI, 11.1%-15.1%; I²  = 97.0%). DR was higher in clinic-based samples compared with community-based samples (15.0%, 95% CI = 12.4%-17.8% vs. 11.5%, 95% CI = 8.9%-14.5%; p = 0.05; I²  = 97.0%) and was higher in countries in the WHO African 19.2% (95% CI, 14.6%-24.3%; I²  = 76.0%), South-East Asia 15.4% (95% CI, 10.0%-21.6%; I²  = 79.1%), and European 15.0% (95% CI, 11.2%-19.2%; I²  = 82.0%) regions. A higher proportion of female patients was significantly associated with a lower prevalence of DR in patients with newly diagnosed T2DM. We observed that the prevalence of DR in patients with newly diagnosed T2DM has remained unchanged over time.

CONCLUSIONS

Globally, DR is a prevalent complication among patients with newly diagnosed T2DM indicating the importance of establishing effective strategies to promote regular screening for the early diagnosis of T2DM alongside routine ophthalmic assessment at the time of T2DM diagnosis to reduce the burden of vision-threatening retinopathy.

Do different lipid components accelerate the pathogenesis and severity of Diabetic Retinopathy?

BACKGROUND

To assess the association of lipid and lipid-derived toxic molecules in pathogenesis and severity of diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM).

METHODS

The present cross-sectional study included 14 healthy individuals (HC) without T2DM, 22 T2DM subjects without DR (DNR), 24 T2DM subjects with mild non-proliferative DR (MNPDR), and 24 T2DM subjects with high-risk proliferative DR (HRPDR). All subjects underwent plasma and vitreous analysis for estimation of total lipid (TL), free fatty acid (FFA), lipid peroxides (LPOs) like malondialdehyde (MDA), 4-Hydroxy-noneal (HNE), the advanced lipoxidation end product (ALE) like Hexanoyl-lysine (HLY) and vascular endothelial growth factor (VEGF) following standard spectrophotometric and enzyme-linked immunosorbent assay (ELISA) methods respectively.

RESULTS

The concentration of TL, FFA, markers of lipid peroxidation and lipoxidation as well as VEGF in plasma and vitreous were found to be significantly elevated stepwise inT2DM subjects (HRPDR > MNPDR > DNR) compared to healthy controls (HC).Further, plasma conventional lipid components like total cholesterol (TCH), low density lipoprotein cholesterol (LDL-C) and triglycerides (TG), FFA and TL showed their significant positive correlations with vitreous level of different LPOs, ALE and VEGF in the DR group.

CONCLUSION

Total lipid and lipid-derived detrimental biomolecules ultimately result in increased secretion of VEGF and thus not only add as associated mediators in the pathogenesis of DR, these also accelerate the severity of microangiopathy in T2DM.

Prevalence of diabetic retinopathy in urban and rural India: A systematic review and meta-analysis

A systematic review and meta-analysis were conducted to estimate the prevalence of diabetic retinopathy (DR) in India’s urban and rural areas. Medline, Scopus, and ScienceDirect databases were searched for population-based studies published in English between January 1990 and April 2021, wherein the prevalence of DR among Indian residents with type 2 diabetes mellitus (DM) was reported. A random-effects model was used to estimate the overall, rural, and urban prevalence. Data from 10 eligible studies were aggregated for meta-analysis. The prevalence of DR was 17.44% (95% confidence interval [CI], 14.33–20.55) in urban and 14.00% (95% CI: 9.13–18.86) in rural population (P = 0.24). The overall DR prevalence was 16.10% (95% CI: 13.16–24.32), and the population prevalence was 1.63% [95% CI: 0.94–2.32]. Prevalence of DR in people with diabetes was lower in the age group of 40–49 years [13.57% (95% CI: 7.16–19.98)] than in the age group of 50–59 years [16.72% (95% CI: 12.80–20.64)] and the age group of 60 years and above [16.55% (95% CI: 12.09–21.00)]. Variability in studies was high: urban (I² = 88.90%); rural (I² = 92.14%). Pooled estimates indicate a narrow difference in DR prevalence among people with diabetes in rural and urban India. The fast urbanization and increasing diabetes prevalence in rural areas underscore the need for providing equitable eye care at the bottom of the health pyramid.

Global prevalence and trends in hypertension and type 2 diabetes mellitus among slum residents: a systematic review and meta-analysis

OBJECTIVE

First, to obtain regional estimates of prevalence of hypertension and type 2 diabetes in urban slums; and second, to compare these with those in urban and rural areas.

DESIGN

Systematic review and meta-analysis.

ELIGIBILITY CRITERIA

Studies that reported hypertension prevalence using the definition of blood pressure ≥140/90 mm Hg and/or prevalence of type 2 diabetes.

INFORMATION SOURCES

Ovid MEDLINE, Cochrane CENTRAL and EMBASE from inception to December 2020.

RISK OF BIAS

Two authors extracted relevant data and assessed risk of bias independently using the Strengthening the Reporting of Observational Studies in Epidemiology guideline.

SYNTHESIS OF RESULTS

We used random-effects meta-analyses to pool prevalence estimates. We examined time trends in the prevalence estimates using meta-regression regression models with the prevalence estimates as the outcome variable and the calendar year of the publication as the predictor.

RESULTS

A total of 62 studies involving 108 110 participants met the inclusion criteria. Prevalence of hypertension and type 2 diabetes in slum populations ranged from 4.2% to 52.5% and 0.9% to 25.0%, respectively. In six studies presenting comparator data, all from the Indian subcontinent, slum residents were 35% more likely to be hypertensive than those living in comparator rural areas and 30% less likely to be hypertensive than those from comparator non-slum urban areas.

LIMITATIONS OF EVIDENCE

Of the included studies, only few studies from India compared the slum prevalence estimates with those living in non-slum urban and rural areas; this limits the generalisability of the finding.

INTERPRETATION

The burden of hypertension and type 2 diabetes varied widely between countries and regions and, to some degree, also within countries.

PROSPERO REGISTRATION NUMBER

CRD42017077381.

Prevalence and associated factors of diabetic retinopathy among type 2 diabetes mellitus patients in Brunei Darussalam - A cross-sectional study

Purpose

To determine the prevalence of diabetic retinopathy (DR) and the factors associated with retinopathy among type 2 diabetes mellitus (DM) patients in Brunei Darussalam.

Methods

Cross-sectional study of all type 2 DM patients who attended diabetic eye screening over a 3-month period at one of four government hospitals. We assessed association between DR with the following variables: age, sex, glycated hemoglobin (HbA1c), duration of DM, hypertension, hyperlipidemia, and microalbuminuria.

Results

There were 341 patients (female, 58.9%; mean age, 55.3 ± 11.9 years) with a mean duration of DM of 9.4 ± 7.4 years and mean serum HbA1c of 8.4% ± 1.9%. The overall prevalence of any DR was 22.6% (95% confidence interval, 18.8–27.1) with prevalence rates of 4.1% (95% confidence interval, 2.1–6.4) for proliferative DR and 9.7% (95% confidence interval, 6.8–13.2) for vision-threatening DR. Multivariate analysis showed that DR was significantly associated with certain age groups (reduced in older age groups), longer duration of DM (11 years or more), poor control (HbA1c >9.0%) and presence of any microalbuminuria.

Conclusions

DR affects one in five patients with DM in Brunei Darussalam, comparable to rates reported for other Asian populations. It is especially worrying that one in ten patients with DM had vision-threatening DR. DR was significantly associated with longer duration of DM, poor control and presence of microalbuminuria but reduced in older age groups. It is important to advocate good control right from the time of diagnosis of DM and institute timely and effective management of retinopathy. DR was significantly associated with longer duration of DM, poor control of diabetes, and presence of microalbuminuria but reduced in older age groups.

The All India Ophthalmological Society - Academic and Research Committee pan-India diabetic retinopathy project "Fixing the missing link": Prevalence data from West Bengal

Purpose:

The aim of this study was to determine the prevalence of diabetic retinopathy (DR) and its risk factors among diabetic patients in rural and urban West Bengal (WB).

Methods:

Patients were screened in the physician's clinic by a team of ophthalmologist, optometrist and counsellor. Demographic details, diabetic control, compliance to eye checkup, awareness regarding diabetic blindness, and visual acuity were recorded using a questionnaire. DR was graded both by indirect ophthalmoscopy and fundus photo taken with a portable fundus camera.

Results:

A total of 1553 subjects were screened over 39 camps across 14 districts of WB over 17 months. The prevalence of DR was 21.51%, with a significant difference between rural (26.55%) and urban (13.89%) areas (P < 0.01). No significant difference with gender was seen (P = 0.99). Presence and grade of DR were related to age, loss of vision, diabetic age, diabetic control, awareness of diabetic blindness and last eye checkup.

Conclusion:

This study provides the first major prevalence data from WB, and gives valuable insight regarding modifiable risk factors for DR. It is also the first DR study in India to be conducted in the physician's clinic. The study results emphasise the need to “fix the missing link” between ophthalmologists and treating physicians to win the battle against DR.

Obesity and risk of age-related eye diseases: a systematic review of prospective population-based studies

BACKGROUND

Obesity is a public health challenge worldwide. The relationship between obesity and age-related eye diseases including cataract, glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR) have remained elusive.

DESIGN AND METHODS

We conducted a systematic review of three electronic databases for longitudinal population-based studies that described associations between measures of obesity including body mass index (BMI), waist-circumference (WC), and waist-to-hip ratio (WHR), and age-related eye diseases.

RESULTS

Our search yielded 1731 articles, of which 14, 10, 16 and 8 articles met our eligibility criteria for cataract, glaucoma, AMD and DR, respectively. BMI-defined obesity was positively associated with incident cataract, incident AMD and incident DR in Western populations, but in Asian populations associations for incident AMD were not significant and associations for incident DR were inverse. WC-defined obesity was associated with incident glaucoma in non-Western populations. WHR-defined obesity but not BMI-defined obesity was associated with the incidence or progression of AMD in two Western studies.

CONCLUSIONS

Overall, we found strong evidence supporting associations between obesity and age-related eye diseases. Further research on the association of abdominal obesity and effect of weight loss and physical activity on age-related eye diseases is warranted to support clinical and public health recommendations.

Magnitude and Determinants of Diabetic Retinopathy Among Indian Diabetic Patients Undergoing Telescreening in India

Purpose: To determine the magnitude, determinants, and public health issues related to diabetic retinopathy (DR) in India using 2019 data from a for-profit telescreening program. Methods: Digital retinal images were captured using a nonmydriatic fundus camera and transferred via the telescreening program to a reading center. Ophthalmologists trained in DR image reading created the DR status reports. Age/sex-adjusted rates of DR, sight-threatening DR (STDR), and diabetic macular edema (DME) were calculated and correlated with known risk factors. Results: Images of 51,760 Indian diabetic patients (103,520 eyes) were reviewed. The prevalence of DR, STDR, and DME was 19.1% (95% confidence interval [CI]: 18.9-19.5), 5.1% (95% CI: 4.9-5.3), and 3.9% (95% CI: 3.7-4.1), respectively. Based on these data, we projected 14.7 million cases of DR, 3.9 million with STDR, and 3.0 million DME cases in India. Statistically significant risk factors for DR were male gender (odds ratio [OR] = 1.19, p < 0.001), older age (χ² = 270, df = 3, p < 0.001), history of cataract surgery (OR = 2.0, p < 0.001), longer duration of diabetes (χ² = 1084, p < 0.001), and type 1 diabetes (OR = 3.9, p = 0.01). There was a statistically significant variation of DR by geographic zones (χ² = 310, p < 0.001). Laser treatment coverage for STDR was 22%. Duration of diabetes (p < 0.001), cataract surgery in the past (p = 0.02), and females (p = 0.001) were predictors of STDR. Conclusion: This model of telescreening for DR provides an additional pathway for screening and preventing diabetes-related visual morbidity in India. The data from this study can be used for epidemiologic and ophthalmic health policies related to diabetes.

Prevalence and trends of the diabetes epidemic in urban and rural India: A pooled systematic review and meta-analysis of 1.7 million adults

PURPOSE

India has experienced a recent sharp increase in diabetes/pre-diabetes. We conducted a systematic-review and meta-analyses to describe the most recent prevalence and trends of pre-diabetes/diabetes in urban and rural India.

METHODS

MethodsA literature search was conducted in PubMed and Scopus databases for population-based studies describing prevalence of diabetes/pre-diabetes in urban/rural populations. Trends were analysed in rural and urban settings overall, genderwise and statewise.

RESULTS

The study reports data from 1,778,706 adults in India (69-studies), from surveys conducted from 1972-2017. Prevalence of diabetes increased in both rural and urban India from 2.4% and 3.3% in 1972 to 15.0% and 19.0% respectively in year 2015-2019. This was independently observed in both genders. Similar increasing prevalence was observed for pre-diabetes, overall and in both genders. In the latest decade (2010-2019) rural and urban prevalence was highest in states of Goa (17.4%) and Tamil Nadu (24.0%) respectively. Statewise analysis observed a wide disparity in prevalence between the North and the South of India.

CONCLUSION

Pooled estimates show a relatively high burden of diabetes and pre-diabetes in rural and urban India, with narrowed urban-rural gap. Hence, it is important to plan urgent primary and secondary prevention strategies to minimize further increase in areas with high prevalence.

Association between body mass index and diabetic retinopathy in Asians: the Asian Eye Epidemiology Consortium (AEEC) study

BACKGROUND/AIMS

Obesity is a well-known risk factor for diabetes, but its association with diabetic retinopathy (DR) is inconclusive, in particular in Asians. We aimed to assess whether body mass index (BMI) is associated with the presence and severity of DR in Asian populations with diabetes.

METHODS

Pooled analysis of individual-level cross-sectional data from 10 010 adults with diabetes who participated in 12 population-based studies conducted in China, India, Japan, Russia (Asian), Singapore and South Korea that were part of the Asian Eye Epidemiology Consortium (AEEC). BMI was calculated as weight in kilograms divided by height in square metres and categorised into normal (<25 kg/m², reference), overweight (25-29.9 kg/m²) and obese (≥30 kg/m²). Any-DR (n=1669) and vision-threatening DR (VTDR, n=489) were assessed from digital retinal photographs and graded according to standard protocols. Each study was analysed separately using multivariable logistic regression models adjusted for age, sex, haemoglobin A1c%, systolic blood pressure and diabetes duration, and the estimated odds ratios (ORs) and 95% confidence interval (CIs) from all studies were then combined using random-effects models.

RESULTS

In multivariable models, obesity showed a significant inverse association with any-DR (pooled OR (95% CI) =0.74 (0.59 to 0.91)) and VTDR (0.75 (0.60 to 0.93)). Similarly, in continuous analysis, BMI showed a significant inverse association with both any-DR (0.93 (0.87 to 0.99)) and VTDR (0.79 (0.68 to 0.92) per SD increase). Overweight did not show a significant association with any-DR.

CONCLUSIONS

Among Asian adults with diabetes, both BMI and obesity showed an inverse association with DR. These findings warrant confirmation in further longitudinal studies.

Overview and project highlights of an initiative to integrate diabetic retinopathy screening and management in the public health system in India

Purpose:

Diabetes is a public health concern in India and diabetic retinopathy (DR) is an emerging cause of visual impairment and blindness. Approximately 3.35–4.55 million people with diabetes mellitus (PwDM) are at risk of vision-threatening DR (VTDR) in India. More than 2/3 of India's population resides in rural areas where penetration of modern medicine is mostly limited to the government public health system. Despite the increasing magnitude, there is no systematic screening for the complications of diabetes, including DR in the public health system. Therefore, a pilot project was initiated with the major objectives of management of DR at all levels of the government health system, initiating a comprehensive program for the detection of eye complications among PwDM at public health noncommunicable disease (NCD) clinics, augmenting the capacity of physicians, ophthalmologists and health support personnel and empowering carers/PwDM to control the risk of DR through increased awareness and self-management.

Methods:

A national task force (NTF) was constituted to oversee policy formulation and provide strategic direction. 10 districts were identified for implementation across 10 states. Protocols were developed to help implement training and service delivery.

Results:

Overall, 66,455 PwDM were screened and DR was detected in 16.2% (10,765) while VTDR was detected in 7.5%. 10.1% of those initially screened returned for the next annual assessment. There was a 7-fold increase in the number of PwDM screened and a 7.6-fold increase in the number of PwDM treated between 2016 and 2018.

Conclusion:

Services for detecting and managing DR can be successfully integrated into the existing public health system.

Prevalence, Pattern and Risk Factors of Retinal Diseases Among an Elderly Population in Nepal: The Bhaktapur Retina Study

Introduction

Retinal diseases are an emerging cause of visual impairment in the developing world. The aim of this study was to explore the prevalence, pattern, and risk factors of retinal diseases in Nepal.

Methods

This is a population-based, cross-sectional study conducted from 2013 to 2015. The sample size was 2100 subjects age 60 years and above from 30 clusters of Bhaktapur district, Nepal. Detailed history, visual acuity, and anterior and posterior segment examinations were performed. Blood sugar and blood pressure were measured.

Results

Complete information was available for 1860 (88.57%) subjects. Mean age was 69.64±7.31 years, ranging from 60 to 95 years. The prevalence of any retinal disorder was 52.37% (95% confidence interval (CI): 50.07–54.66%). The prevalence of retinal disorders increased with ageing: 51.26% between 60 and 69 years and 53.05% among those age 80 years and above. Age-related macular degeneration (AMD) was the most common retinal disease (35.43%), followed by hypertensive retinopathy (4.35%), epiretinal membrane (ERM) (3.66%), branch retinal vein occlusion (BRVO) (2.90%), and diabetic retinopathy (DR) (2.15%). Other rare retinal disorders included myopic fundus (0.86%), chorioretinal scar (0.54%), retinal holes (0.32%), retinitis pigmentosa (0.32%), retinal detachment (0.16%), and coloboma (0.11%). In multivariate logistic regression analysis, those with prior cataract surgery (odds ratio (OR), 1.71; 95% CI: 1.32–2.22, p < 0.001) and systemic hypertension (OR, 1.21; 95% CI: 1.001–1.47, p = 0.049) had significantly increased retinal disorders.

Conclusion

Prevalence of retinal disorder was 52.37% at age 60 years and above. AMD, hypertensive retinopathy, ERM, BRVO, and DR were the most common retinal disorders. Retinal disorders increased with ageing. Retinal disorders were found associated with hypertension and prior cataract surgery. Timely screening, control of blood sugar and high blood pressure, and regular eye check-ups could help to save vision from retinal diseases.

Knowledge, attitudes and eye health-seeking behaviours in a population-based sample of people with diabetes in rural China

AIMS

To assess knowledge of diabetes and acceptance of eye care among people with diabetes in rural China, to improve service uptake.

METHODS

Population-based study of people in Guangdong, China, with glycosylated haemoglobin A1c≥6.5% and/or known history of diabetes. Between August and November 2014, participants answered a questionnaire (based on Delphi process/previous focus groups) on medical history, demographic characteristics, self-rated health and vision, knowledge about diabetes and diabetic retinopathy, quality of local healthcare, barriers to treatment, likely acceptance of eye exams and treatment, and interventions rated most likely to improve service uptake. Presenting visual acuity was assessed, fundus photography performed and images graded by trained graders. Potential predictors of accepting care were evaluated and confounders adjusted for using logistic regression.

RESULTS

A total of 562 people (9.6% (256/5825), mean age 66.2±9.84 years, 207 (36.8%) men) had diabetes, 118 (22.3%) previously diagnosed. 'Very likely' or 'likely' acceptance of laser treatment (140/530=26.4%) was lower than for eye exams (317/530=59.8%, p<0.001). Predictors of accepting both exams and laser included younger age (p<.001) and prior awareness of diabetes diagnosis (p=0.004 and p=0.035, respectively). The leading barrier to receiving diabetes treatment was unawareness of diagnosis (409/454, 97.2%), while interventions rated most likely to improve acceptance of eye exams included reimbursement of travel costs (387/562, 73.0%), video or other health education (359/562, 67.7%) and phone call reminders (346/562, 65.3%).

CONCLUSIONS

Improving diagnosis of diabetes, along with incentives, education and communication strategies, is most likely to enhance poor acceptance of diabetic eye care in this setting.

Effectiveness of Teleretinal Imaging-Based Hospital Referral Compared With Universal Referral in Identifying Diabetic Retinopathy: A Cluster Randomized Clinical Trial

Question

Does screening for diabetic retinopathy by teleretinal imaging in physician offices in India lead to higher adherence to eye hospital referral and a greater yield of diabetic retinopathy cases compared with a strategy of referral of all eligible patients with diabetes?

Findings

In a cluster randomized clinical trial of 801 patients with diabetes, proportionately more patients in the teleretinal group attended the hospital eye examination and had confirmed diabetic retinopathy compared with the control group.

Meaning

The results suggest that, in the Indian setting, teleretinal screening is an effective approach for identifying diabetic retinopathy.

Importance

Studies in high-income countries provide limited evidence from randomized clinical trials on the benefits of teleretinal screening to identify diabetic retinopathy (DR).

Objective

To evaluate the effectiveness of teleretinal-screening hospital referral (TR) compared with universal hospital referral (UR) in people with diabetes.

Design, Setting, and Participants

A cluster randomized clinical trial of 8 diabetes clinics within 10 km from Aravind Eye Hospital (AEH), Madurai, India, was conducted. Participants included 801 patients older than 50 years. The study was conducted from May 21, 2014, to February 7, 2015; data analysis was performed from March 12 to June 16, 2015.

Interventions

In the TR cohort, nonmydriatic, 3-field, 45° retinal images were remotely graded by a retinal specialist and patients with DR, probable DR, or ungradable images were referred to AEH for a retinal examination. In the UR cohort, all patients were referred for a retinal examination at AEH.

Main Outcomes and Measures

Hospital-diagnosed DR.

Results

Of the 801 participants, 401 were women (50.1%) (mean [SD] age, 60.0 [7.3] years); mean diabetes duration was 8.6 (6.6) years. In the TR cohort, 96 of 398 patients (24.1%) who underwent teleretinal imaging were referred with probable DR (53 [13.3%]) or nongradable images (43 [10.8%]). Hospital attendance at AEH was proportionately higher with TR (54 of 96 referred [56.3%]) compared with UR (150 of 400 referred [37.5%]). The intention-to-treat analysis based on all patients eligible for referral in each arm showed that proportionately more patients with TR (36 of 96 [37.5]%) were diagnosed with DR compared with UR (50 of 400 [12.5%]) (unadjusted risk ratio [RR], 3.00; 95% CI, 2.01-4.48). These results were little changed by inclusion of covariates (RR, 2.72; 95% CI, 1.90-3.91). The RR was lower in the per-protocol analysis based on all patients who adhered to referral (covariate-adjusted RR, 1.75; 95% CI, 1.12-2.74). Diagnoses of DR were predominantly mild or moderate nonproliferative DR (36 in TR and 43 in UR). In the UR arm, there were 4 cases of severe nonproliferative DR and 2 cases of proliferative DR. Age (RR, 0.98; 95% CI, 0.95-0.99), female sex (RR, 0.79; 95% CI, 0.64-0.98), and hypertension diagnosis (RR, 0.81; 95% CI, 0.68-0.95) were factors associated with lower attendance. Those with higher secondary educational level or more were twice as likely to attend (RR, 2.00; 95% CI, 1.32-3.03).

Conclusions and Relevance

The proportionate yield of DR cases was higher in the TR arm, confirming the potential benefit, at least in the setting of eye hospitals in India, of a targeted referral approach using teleretinal screening to identify patients with DR.

Trial Registration

ClinicalTrials.gov identifier: NCT02085681

Awareness and knowledge of diabetic retinopathy and associated factors in Goa: A hospital-based cross-sectional study

Purpose

To assess the awareness and knowledge about diabetic retinopathy (DR) and associated factors among patients visiting the tertiary health center in Goa.

Methods

A cross-sectional descriptive study was conducted using a standard predesigned and pretested closed-ended structured questionnaire to assess the awareness, knowledge, attitude and practice about DR among patients visiting a tertiary health center.

Results

Three hundred and fifty-eight subjects participated in the study. Only 125 (34.9% [95% CI: 30.0-40.1]) subjects were aware of DR and 122 (34.1% [95% CI: 29.2-39.2]) had adequate knowledge about DR. Awareness and knowledge of DR were significantly high among the subjects who completed college level of education (66.7%, OR = 2.78; 95% CI: 1.73-4.48, P < 0.001 and 55.9%, OR = 3.92; 95% CI: 2.41-6.38, P < 0.001) and who spoke English (52.5%, OR = 3.37; 95% CI: 2.14-5.30, P < 0.001 and 50.4%, OR = 3.26; 95% CI: 2.07-5.14, P < 0.001). Christians reported better knowledge about DR compared to other religions (48.8%, OR = 2.27; 95% CI: 1.38-3.75, P = 0.005). Negative association was noted between the knowledge of DR and presence of diabetes (29.4%, OR = 0.64; 95% CI: 0.41-0.99, P = 0.048). The practice pattern was strongly associated (OR = 7.47; 95% CI: 4.51-12.38, P < 0.001) with the knowledge of DR. Attitude was not influenced by any of the factors.

Conclusion

We found that awareness and knowledge about DR were unsatisfactory; literacy contributed significantly toward it. These findings also suggest that there is an immediate need to enhance the awareness and knowledge of diabetic eye diseases in order to reduce the burden of visual impairment.

IDF Diabetes Atlas: A review of studies utilising retinal photography on the global prevalence of diabetes related retinopathy between 2015 and 2018

AIMS

The purpose of this study is to assess the prevalence of diabetic retinopathy (DR) world-wide from articles published since 2015 where the assessment of the presence and severity of DR was based on retinal images.

METHODS

A total of 4 databases were searched for the MESH terms diabetic retinopathy and prevalence. Of 112 publications 32 studies were included and individual data pooled for analysis. The presence of any DR or diabetic macular edema (DME) was recorded and severity as mild, moderate or severe non-proliferative DR (NPDR), proliferative DR (PDR) and DME and/or clinically significant macular edema (CSME). The level of severity of DR reported refer to persons with diabetes and not individual eyes.

RESULTS

The global prevalence of DR and DME, for the period 2015 to 2019 were 27.0% for any DR comprising of 25.2%, NPDR, 1.4% PDR and 4.6% DME. The lowest prevalence was in Europe at 20.6% and South East Asia at 12.5% and highest in Africa at 33.8%, Middle East and North Africa 33.8%, and the Western Pacific region at 36.2%.

CONCLUSIONS

This study illustrated difficulties in deriving a meaningful global prevalence rate for DR and DME due to the lack of uniformity in defining the study populations, methodological differences, retinal image capture and grading criteria. Therefore, international consensus is required using a minimal data set for future studies.

Diagnostic Accuracy of Community-Based Diabetic Retinopathy Screening With an Offline Artificial Intelligence System on a Smartphone

Importance

Offline automated analysis of retinal images on a smartphone may be a cost-effective and scalable method of screening for diabetic retinopathy; however, to our knowledge, assessment of such an artificial intelligence (AI) system is lacking.

Objective

To evaluate the performance of Medios AI (Remidio), a proprietary, offline, smartphone-based, automated system of analysis of retinal images, to detect referable diabetic retinopathy (RDR) in images taken by a minimally trained health care worker with Remidio Non-Mydriatic Fundus on Phone, a smartphone-based, nonmydriatic retinal camera. Referable diabetic retinopathy is defined as any retinopathy more severe than mild diabetic retinopathy, with or without diabetic macular edema.

Design, Setting, and Participants

This prospective, cross-sectional, population-based study took place from August 2018 to September 2018. Patients with diabetes mellitus who visited various dispensaries administered by the Municipal Corporation of Greater Mumbai in Mumbai, India, on a particular day were included.

Interventions

Three fields of the fundus (the posterior pole, nasal, and temporal fields) were photographed. The images were analyzed by an ophthalmologist and the AI system.

Main Outcomes and Measures

To evaluate the sensitivity and specificity of the offline automated analysis system in detecting referable diabetic retinopathy on images taken on the smartphone-based, nonmydriatic retinal imaging system by a health worker.

Results

Of 255 patients seen in the dispensaries, 231 patients (90.6%) consented to diabetic retinopathy screening. The major reasons for not participating were unwillingness to wait for screening and the blurring of vision that would occur after dilation. Images from 18 patients were deemed ungradable by the ophthalmologist and hence were excluded. In the remaining participants (110 female patients [51.6%] and 103 male patients [48.4%]; mean [SD] age, 53.1 [10.3] years), the sensitivity and specificity of the offline AI system in diagnosing referable diabetic retinopathy were 100.0% (95% CI, 78.2%-100.0%) and 88.4% (95% CI, 83.2%-92.5%), respectively, and in diagnosing any diabetic retinopathy were 85.2% (95% CI, 66.3%-95.8%) and 92.0% (95% CI, 97.1%-95.4%), respectively, compared with ophthalmologist grading using the same images.

Conclusions and Relevance

These pilot study results show promise in the use of an offline AI system in community screening for referable diabetic retinopathy with a smartphone-based fundus camera. The use of AI would enable screening for referable diabetic retinopathy in remote areas where services of an ophthalmologist are unavailable. This study was done on patients with diabetes who were visiting a dispensary that provides curative services to the population at the primary level. A study with a larger sample size may be needed to extend the results to general population screening, however.

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.

Prevalence and risk factors of diabetic retinopathy among an elderly population with diabetes in Nepal: the Bhaktapur Retina Study

Aim

Diabetic retinopathy (DR) is an emerging cause of blindness in developing countries. This study aimed to explore the prevalence and risk factors of DR in an elderly population in Nepal.

Subjects and methods

This is a population-based, cross-sectional study. A total of 1860 subjects at the age 60 years and above participated (response rate 88.6%). A detailed history was obtained, presenting and best-corrected visual acuity were measured, and anterior segment and posterior segment examinations were carried out. Blood pressure and random blood sugar were recorded; body mass index was calculated, and abdominal girth was measured. DR was graded by clinical examination using Early Treatment Diabetic Retinopathy Study criteria.

Results

Diabetes was found in 168 (9%) subjects (mean age 69.6 years), 31 (18.5%) of whom were newly diagnosed. The prevalence of DR was 23.8% (95% confidence interval [CI]: 17.7%–31%) among the persons with diabetes. The prevalence of DR among newly diagnosed subjects with diabetes was 6.5% (95% CI: 0.8%–21.4%). The prevalence of vision-threatening DR was 9.5% (95% CI: 5.5%–15%) and was higher in males. The prevalence of DR was 83.3% (95% CI: 35.9%–99.6%) among those with diabetes for over 20 years. In multivariable logistic regression analysis, duration of diabetes, hypertension, and alcohol consumption were significantly associated with DR.

Conclusion

DR is a common problem among the elderly population with diabetes in Nepal. The duration of diabetes, hypertension, and alcohol consumption are the risk factors for the development of DR. Strategies have to be developed for timely diagnosis of diabetes and screening for DR.

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.

The Beijing Desheng Diabetic Eye Study: rationale, design, methodology and baseline data

AIM

To present the rationale, design, methodology, and the baseline data of the Beijing Desheng Diabetic Eye Study (BDDES), and to determine the prevalence of diabetic retinopathy (DR) and possible risk factors in patients with type 2 diabetes mellitus (T2DM) in an urban community of Beijing, China.

METHODS

Community-based prospective cohort study of persons diagnosed with T2DM aged 30y or older. The main variables of interest are the presence and progression of DR as determined by the standardized ETDRS grading of seven fields fundus photographs. The presence and severity of DR were analyzed for possible correlations to non-genetic and genetic dispositions.

RESULTS

A total of 1438 participants with data available for analysis, the prevalence of any DR was 35.4%. The prevalence of mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR, and proliferative diabetic retinopathy was 27.7%, 2.6%, 0.5% and 4.5%, respectively. By multiple logistic regression analysis, risk factors for the presence of any DR included male (P=0.031), lower income level (P=0.011), lower education background (P=0.022), longer duration of diabetes (P=0.001), younger age at diabetic onset (P=0.001), higher systolic blood pressure (P=0.007), higher glycosylated hemoglobin A1c levels (P=0.001), high albuminuria (P=0.03), and use of insulin (P<0.001). For vision-threatening DR, four factors were significant: younger age at diabetic onset (P<0.001), higher systolic blood pressure (P=0.042), high albuminuria (P<0.001), and use of insulin (P<0.001).

CONCLUSION

The BDDES is the first large-scale ongoing cohort study of a Chinese urban population of persons with type 2 diabetes. Using standardized grading system comparable to large cohort studies from western populations, our baseline data shows that the prevalence of DR and major risk factors in this Chinese ethnic population are comparable to that found in the western population studies.

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.