Diabetic retinopathy in a black population: the Barbados Eye Study

Autonomous Artificial Intelligence Increases Access and Health Equity in Underserved Populations with Diabetes

Diabetic eye disease (DED) is a leading cause of blindness in the world. Early detection and treatment of DED have been shown to be both sight-saving and cost-effective. As such, annual testing for DED is recommended for adults with diabetes and is a Healthcare Effectiveness Data and Information Set (HEDIS) measure. However, adherence to this guideline has historically been low, and access to this sight-saving intervention has particularly been limited for specific populations, such as Black or African American patients. In 2018, the US Food and Drug Agency (FDA) De Novo cleared autonomous artificial intelligence (AI) for diagnosing DED in a primary care setting. In 2020, Johns Hopkins Medicine (JHM), an integrated healthcare system with over 30 primary care sites, began deploying autonomous AI for DED testing in some of its primary care clinics. In this retrospective study, we aimed to determine whether autonomous AI implementation was associated with increased adherence to annual DED testing, and whether this was different for specific populations. JHM primary care sites were categorized as "non-AI" sites (sites with no autonomous AI deployment over the study period and where patients are referred to eyecare for DED testing) or "AI-switched" sites (sites that did not have autonomous AI testing in 2019 but did by 2021). We conducted a difference-in-difference analysis using a logistic regression model to compare change in adherence rates from 2019 to 2021 between non-AI and AI-switched sites. Our study included all adult patients with diabetes managed within our health system (17,674 patients for the 2019 cohort and 17,590 patients for the 2021 cohort) and has three major findings. First, after controlling for a wide range of potential confounders, our regression analysis demonstrated that the odds ratio of adherence at AI-switched sites was 36% higher than that of non-AI sites, suggesting that there was a higher increase in DED testing between 2019 and 2021 at AI-switched sites than at non-AI sites. Second, our data suggested autonomous AI improved access for historically disadvantaged populations. The adherence rate for Black/African Americans increased by 11.9% within AI-switched sites whereas it decreased by 1.2% within non-AI sites over the same time frame. Third, the data suggest that autonomous AI improved health equity by closing care gaps. For example, in 2019, a large adherence rate gap existed between Asian Americans and Black/African Americans (61.1% vs. 45.5%). This 15.6% gap shrank to 3.5% by 2021. In summary, our real-world deployment results in a large integrated healthcare system suggest that autonomous AI improves adherence to a HEDIS measure, patient access, and health equity for patients with diabetes - particularly in historically disadvantaged patient groups. While our findings are encouraging, they will need to be replicated and validated in a prospective manner across more diverse settings.

Diabetes Epidemiology Among Adults in Port-au-Prince, Haiti: A Cross-Sectional Study

Introduction

Diabetes mellitus is a chronic noncommunicable disease associated with death and major disability, with increasing prevalence in low- and middle-income countries. There is limited population-based data about diabetes in Haiti. The objective of this study was to assess the prevalence of diabetes and associated factors among adults in Port-au-Prince, Haiti using a population-based cohort.

Methods

This study analyzes cross-sectional enrollment data from the population-based Haiti Cardiovascular Disease Cohort Study, conducted using multistage sampling with global positioning system waypoints in census blocks in the metropolitan area of Port-au-Prince, Haiti. A total of 3,005 adults ≥18 years old were enrolled from March 2019 to August 2021. We collected socio-demographic data, health-related behaviors, and clinical data using standardized questionnaires. Diabetes was defined as any of the following criteria: enrollment fasting glucose value ≥ 126 mg/dL or non-fasting glucose ≥ 200 mg/dL, patient self-report of taking diabetes medications, or study physician diagnosis of diabetes based on clinical evaluation.

Results

Among 2985 (99.3%) with complete diabetes data, median age was 40 years, 58.1% were female, and 17.2% were obese. The prevalence of diabetes was 5.4% crude, and 5.2% age standardized. In unadjusted analysis, older age, higher body mass index (BMI), low physical activity, low education were associated with a higher odds of diabetes. After multivariable logistic regression, older age [60+ vs 18-29, Odds Ratio (OR)17.7, 95% CI 6.6 to 47.9] and higher BMI (obese vs normal/underweight, OR 2.7, 95% CI 1.7 to 4.4) remained statistically significantly associated with higher odds of diabetes.

Conclusion

The prevalence of diabetes was relatively low among adults in Port-au-Prince, but much higher among certain groups (participants who were older and obese). The Haitian health system should be strengthened to prevent, diagnose, and treat diabetes among high-risk groups.

Awareness of Diabetic Retinopathy: Insight From the National Health and Nutrition Examination Survey

INTRODUCTION

This study determines the prevalence and associated correlates of people unaware of their diabetic retinopathy diagnosis in the U.S.

METHODS

Participants unaware of diabetic retinopathy from the National Health and Nutrition Examination Survey from 2005 to 2008 were identified. The prevalence of those unaware of their diabetic retinopathy diagnosis was determined. Descriptive statistics and logistic regression were used to determine correlates associated with being unaware of one's diabetic retinopathy diagnosis (completed in 2018‒2020).

RESULTS

Among 5,563 participants aged ≥40 years who underwent fundus photography, the prevalence of those unaware of their diabetic retinopathy diagnosis was 10.6% (9.8 million). This included 23.1% of those with self-reported diabetes (2.9 million) and 6.8% of those who reported not having diabetes (6.9 million). Among participants reporting diabetes with photographic evidence of retinopathy, 70.1% were unaware. Among individuals with self-reported diabetes, correlates of being unaware of one's diabetic retinopathy diagnosis included diabetes diaganosis for ≥10 years (OR=3.15, 95% CI=1.78, 5.56), HbA1c ≥6.5% (OR=2.92, 95% CI=1.65, 5.18), and treatment with insulin only (OR=4.04, 95% CI=1.43, 11.39). Self-reported hypertension was associated with decreased odds of undiagnosed diabetic retinopathy (OR=0.48, 95% CI=0.28, 0.82). Among those without self-reported diabetes, correlates of being unaware of diabetic retinopathy included older age (OR=1.02, 95% CI=1.01, 1.04), male sex (OR=1.83, 95% CI=1.31, 2.56), Black race (OR=1.81, 95% CI=1.12, 2.92), Hispanic race/ethnicity (OR=1.60, 95% CI=1.14, 2.25), elevated blood pressure (OR=1.54, 95% CI=1.23, 1.93), current smoking (OR=1.74, 95% CI=1.21, 2.51), and history of stroke (OR=2.20, 95% CI=1.06, 4.58).

CONCLUSIONS

A substantial proportion of individuals with diabetic retinopathy are unaware of the diagnosis. These data provide a path toward refining efforts to diagnose and treat diabetic retinopathy to decrease the burden of preventable blindness.

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.

Racial/Ethnic Disparities in Ophthalmology Clinical Trials Resulting in US Food and Drug Administration Drug Approvals From 2000 to 2020

Importance

Diverse, representative enrollment in pivotal clinical trials is vital to sufficiently power subgroup analyses and ensure equity and validity of trial results.

Objective

To evaluate the racial/ethnic representation, trends, and disparities in clinical trials leading to US Food and Drug Administration (FDA) ophthalmology drug approvals from 2000 to 2020.

Design, Setting, and Participants

This cohort study used data from participants in clinical trials of drugs for neovascular age-related macular degeneration (AMD), open-angle glaucoma (OAG), and expanded indications for diabetic retinopathy (DR) from January 1, 2000, to December 31, 2020. Trial data were sourced from FDA reviews, ClinicalTrials.gov, and relevant linked studies. National expected racial/ethnic proportions were sourced from public National Eye Institute prevalence data as well as published rates scaled using US Census Bureau data.

Main Outcomes and Measures

The primary outcome measures were the distribution of and change over time in the racial/ethnic proportion of participants in clinical trials leading to FDA approval of drugs for AMD, OAG, and DR.

Results

During the 20-year period, 31 clinical trials were identified for 13 medications with 18 410 participants. The distribution of trial participants was different from the expected trial distribution for most approvals with regard to race/ethnicity (12 drugs) and sex (10 drugs). Compared with the first decade (2000-2010), trials conducted in the second decade (2011-2020) showed increases in enrollment of Asian (odds ratio [OR], 2.30; 95% CI, 1.97-2.68; P < .001) and Hispanic or Latinx participants (OR, 1.74; 95% CI, 1.49-2.03; P < .001) for AMD, Asian participants (OR, 2.21; 95% CI, 1.46-3.42; P < .001) for DR, and Black (OR, 1.60; 95% CI, 1.43-1.78; P < .001) and Hispanic or Latinx participants (OR, 10.31; 95% CI, 8.05-13.35; P < .001) for OAG. There was a decrease in Black participants in DR trials (OR, 0.58; 95% CI, 0.42-0.79; P < .001). Based on these trends, the enrollment incidence ratio is expected to worsen by 2050, with overrepresentation of white participants vs underrepresentation of Black and Hispanic or Latinx participants in trials of drugs for AMD (1.08 vs 0.04 vs 0.77), DR (1.83 vs 0.87 vs 0.59), and OAG (1.62 vs 0.90 vs 0.37).

Conclusions and Relevance

In this cohort study, Black, Hispanic or Latinx, and other non-White participants were underrepresented in clinical trials leading to FDA ophthalmology drug approvals compared with the expected disease burden and racial/ethnic distribution in the US. Although there was meaningful improvement from 2000 to 2020, further efforts to increase minority enrollment in clinical trials seem to be warranted.

Cocoa olein glycerolysis with lipase

In this paper we present the valorization of cocoa olein obtained from the acid fat-splitting of soapstocks. The aim is to develop a solvent free process (enzymatically catalyzed) to maximize the production of a final product with high content of monoglycerides (MAG) and diglycerides (DAG). The effect of the enzyme dose, glycerol content, reaction times as well as the modification of the raw material and pressure were studied. The yield of the reaction increased up to 90-95% when using a vacuum of 2-3 mbar at 65 °C, enough to evaporate the water which is generated as a by-product, an enzyme dose of 1% and molar ratio oil:glycerol of 1:2. The highest yield in terms of MAG and DAG production was obtained by starting from a raw material which was rich in free acidity (FFA), rendering oil with 33.4 and 44.2% MAG and DAG, respectively. Short reaction times (6-8 h) were observed compared to previously reported results (24 h).

Systemic and ocular diseases associated with the development of diabetic macular edema among Japanese patients with diabetes mellitus

Background

Diabetic macular edema (DME) causes severe vision loss among patients with diabetes mellitus (DM). We aimed to investigate systemic and ocular diseases associated with the development of DME in a Japanese population.

Methods

A total of 3.11 million Japanese subjects who were registered in the database of the Japan Medical Data Center from 2005 to 2014 were analyzed. Subjects with DM were defined as individuals who had been prescribed any therapeutic medications for DM, and associated diseases were analyzed. The periods assessed were one year before the development of DME among patients with DME and one year before the last visit to an ophthalmic clinic among patients without DME.

Results

A total of 17,403 patients with DM satisfied the inclusion and exclusion criteria, and 420 patients developed DME. Univariate analysis revealed significant associations between 55 diseases, including 39 systemic and 16 ocular diseases, and DME development. Logistic analysis identified 21 systemic diseases and 10 ocular diseases as significant factors associated with DME development.

Conclusion

Various types of systemic and ocular diseases are associated with DME development. Subjects with DM who present these risk factors must be carefully monitored to prevent visual impairment.

The African American Eye Disease Study: Design and Methods

PURPOSE

To describe the study design, operational and recruitment strategies, procedures, and baseline characteristics of the African American Eye Disease Study (AFEDS), a population-based assement of the prevalence of visual impairment, ocular disease, visual function, and health-related quality of life in African Americans.

METHODS

This population-based, cross-sectional study included over 6000 African Americans 40 years and older residing in and around Inglewood, California. A detailed interview and eye examination was performed on each eligible participant. The interview included an assessment of demographic, behavioral, and ocular risk factors and health-related and vision-related quality of life. The eye examination included measurements of visual acuity, intraocular pressure, visual fields; fundus and optic disc photography; a detailed anterior and posterior segment examination; and measurements of blood pressure, glycosylated hemoglobin levels, and blood glucose levels.

RESULTS

The AFEDS cohort includes more than 6000 participants that have completed a home questionnaire and a comprehensive eye examination. The majority of participants were female (63%), the average (± standard deviation) overall age was 60.9 (±11.3). Participants are mostly working (40%) or retired (41%), non-smoking (57%), partial drinking (54%), and with at least some college education (38%). A trust-development recruitment strategy was refined in order to overcome challenges in study participation.

CONCLUSION

The AFEDS is the largest epidemiologic eye study among African Americans to date. The AFEDS cohort will provide information about the prevalence and risk factors of ocular disease in the largest ophthalmologic study population of African Americans in the United States.

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.

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: Focus on Minority Populations

Diabetic retinopathy is a major cause of blindness in the United States. With rise of the epidemic of obesity and diabetes in the USA and around the globe, serious and common diabetic complications are evolving as a major public health problem, particularly among minority populations. These populations are disproportionately affected by diabetes and 2-3 times more likely to develop visually significant complications. In this highly illustrated review article, we discuss the diabetic epidemic, highlighting the biology and the pathophysiologic mechanisms of this disorder on the anatomy of the eye. We also discuss the risk factors and the implications for minority populations. For the health care providers, we provide cutting edge information and imminently relevant information to help evaluate, manage, and know when to refer their patients to a specialist in ophthalmology to quell the tide of the epidemic.

Prevalence of Diabetic Retinopathy and Blindness in Indonesian Adults With Type 2 Diabetes

PURPOSE

To report the prevalence of diabetic retinopathy (DR) and DR-related blindness in an Indonesian population with type 2 diabetes.

METHODS

Design: Population-based cross-sectional study.

SETTING

Community health centers.

STUDY POPULATION

We recruited 1184 people aged older than 30 years with type 2 diabetes residing in Jogjakarta, Indonesia. Multistage, clustered random sampling based on regencies and districts in Jogjakarta was used.

OBSERVATION PROCEDURE

Detailed interviews, general and eye examinations, and anthropometric measurement were performed. Disc- and macula-centered retinal photographs were taken to assess DR. The definition of DR followed a modified Airlie House classification system and was categorized into mild, moderate, and vision-threatening DR (VTDR).

MAIN OUTCOME MEASURE(S)

Prevalence and severity of DR.

RESULTS

The median (range) age and diabetes duration of participants was 59 (52-65) and 4 (2-9) years. The prevalence of DR was 43.1% (95% confidence interval 39.6%-46.6%), with mild, moderate, and severe NPDR and PDR to be 9.41%, 7.46%, 11.1%, and 12.1%, respectively. The prevalence of VTDR was 26.3% (23.1%-29.5%). Longer diabetes duration, higher fasting glucose, presence of hypertension, and foot ulcers were associated with DR and VTDR. The prevalence of bilateral blindness was 4% and 7.7% in persons with DR and VTDR.

CONCLUSIONS

This study reports a high prevalence of any DR and VTDR among Indonesian adults with type 2 diabetes in urban and rural areas: approximately 1 in 4 adults with diabetes had VTDR and 1 in 12 of those with VTDR was bilaterally blind, suggesting the need for appropriate screening and management of DR among the Indonesian population.

The Status of Maculopathy in Diabetes and Prediabetes Patients in a Population-Based Study Detected by Optical Coherence Tomography: The 2011 Health Examination Survey in Beijing

Objective

The aim of the study was to investigate the prevalence and the risk factors of maculopathy detected by optical coherence tomography (OCT) in a Chinese population with diabetes or prediabetes. Methods. 8,155 people were randomly selected to participate in the 2011 annual Health Examination Survey in Beijing. A 75 g oral glucose tolerance test (OGTT) was tested in 3760 subjects with fasting plasma glucose (FPG) ≥ 5.6 mmol/L. Of 3,760 subjects, 583 were also randomly selected to take OCT.

Results

In this study population, 21 (3.95%) patients had maculopathy. Eight patients had diabetes macular edema (DME) and the prevalence was 6.72% in diabetes patients and 1.51% in all subjects. Eleven patients had age-related macular degeneration (AMD) and the prevalence was 3.36% in diabetes patients and 2.07% in all subjects. Logistic regression model confirmed that elevated HbA1c (p < 0.001) and systolic pressure (p < 0.05) made significant contributions to DME. Stepwise regression analysis revealed that HbA1c and blood creatinine were significantly independent influence factors for central subfield thickness (CST) (p = 0.01, p < 0.001).

Conclusions

High prevalence of maculopathy was found in patients with diabetes in a Chinese population. Maculopathy poses a significant public health problem in China with rapid rising trend of diabetes.

The National Eye Survey of Trinidad and Tobago (NESTT): Rationale, Objectives and Methodology

PURPOSE

This paper describes the rationale, study design and procedures of the National Eye Survey of Trinidad and Tobago (NESTT). The main objective of this survey is to obtain prevalence estimates of vision impairment and blindness for planning and policy development.

METHODS

A population-based, cross-sectional survey was undertaken using random multistage cluster sampling, with probability-proportionate-to-size methods. Eligible participants aged 5 years and older were sampled from the non-institutional population in each of 120 cluster segments. Presenting distance and near visual acuity were screened in their communities. People aged 40 years and older, and selected younger people, were invited for comprehensive clinic assessment. The interview included information on potential risk factors for vision loss, associated costs and quality of life. The examination included measurement of anthropometrics, blood glucose, refraction, ocular biometry, corneal hysteresis, and detailed assessment of the anterior and posterior segments, with photography and optical coherence tomography imaging. Adult participants were invited to donate saliva samples for DNA extraction and storage.

RESULTS

The fieldwork was conducted over 13 months in 2013-2014. A representative sample of 10,651 individuals in 3410 households within 120 cluster segments identified 9913 people who were eligible for recruitment.

CONCLUSION

The study methodology was robust and adequate to provide the first population-based estimates of the prevalence and causes of visual impairment and blindness in Trinidad and Tobago. Information was also gathered on risk factors, costs and quality of life associated with vision loss, and on normal ocular parameters for the population aged 40 years and older.

Rationale and Methodology for a Community-Based Study of Diabetic Retinopathy in an Indonesian Population with Type 2 Diabetes Mellitus: The Jogjakarta Eye Diabetic Study in the Community

PURPOSE

There are no available data about diabetic retinopathy (DR) in the Indonesian population. This report summarizes the rationale and study design of the Jogjakarta Eye Diabetic Study in the Community (JOGED.COM), a community-based study to estimate the prevalence and risk factors of DR in persons with type 2 diabetes in Jogjakarta, Indonesia.

METHODS

The JOGED.COM aimed to examine a cross-sectional sample of 1200 persons with type 2 diabetes aged 30 years and older residing in the study area. We identified 121 community health centers (CHCs) in Jogjakarta and listed 35 CHCs with non-communicable diseases facilities. Multi-stage, clustered random sampling was used to select 22 CHCs randomly. We included CHCs with coverage population >30,000, and excluded those classified as 100% rural. Lists of persons with diabetes confirmed by their family physician were provided from each CHC. Examinations procedures included detailed interviews, general and eye examinations, anthropometry and body composition scan, and dilated fundus photography.

RESULTS

We collaborated with local health authorities, family physicians, and local health practitioners in the recruitment phase. A total of 1435 invitations were distributed, and 1184 people (82.5%) with type 2 diabetes participated in this study, of whom 1138 (79.3%) had completed data with gradable retinal images.

CONCLUSIONS

JOGED.COM is the first epidemiologic study of DR in an Indonesian population. This study will provide key information about the prevalence and risk factors of DR in the community. These data are very important for future health promotion programs to reduce the burden of DR in the population.

Global Estimates on the Number of People Blind or Visually Impaired by Diabetic Retinopathy: A Meta-analysis From 1990 to 2010

OBJECTIVE

To estimate global and regional trends from 1990 to 2010 of the prevalence and number of persons visually impaired specifically by diabetic retinopathy (DR), as a complication of the precipitous trends in global diabetes, is fundamental for health planning purposes.

RESEARCH DESIGN AND METHODS

The meta-analysis of published population studies from 1990 to 2012 for the Global Burden of Disease Study 2010 (GBD) yielded estimated global regional trends in DR among other causes of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60).

RESULTS

Globally in 2010, out of overall 32.4 million blind and 191 million visually impaired people, 0.8 million were blind and 3.7 million were visually impaired because of DR, with an alarming increase of 27% and 64%, respectively, spanning the two decades from 1990 to 2010. DR accounted for 2.6% of all blindness in 2010 and 1.9% of all MSVI worldwide, increasing from 2.1% and 1.3%, respectively, in 1990. These figures were lower in regions with younger populations (<2% in East and Southeast Asia and Oceania) than in high-income regions (North America, Western Europe, and Australasia) with relatively aging populations (>4%).

CONCLUSIONS

The number of persons with visual impairment due to DR worldwide is rising and represents an increasing proportion of all blindness/MSVI causes. Age-standardized prevalence of DR-related blindness/MSVI was higher in sub-Saharan Africa and South Asia. One out of 39 blind people had blindness due to DR, and 1 out of 52 visually impaired people had visual impairment due to DR.

Prevalence of Diabetic Retinopathy in a Clinic Population from Puerto Rico

PURPOSE

Diabetic retinopathy (DR) is a preventable or treatable cause of blindness in the adult population. The prevalence of diabetes mellitus (DM) in Puerto Ricans is the highest among Hispanics. This study evaluated the prevalence of DR in a screening program of DM subjects in a clinic system in Puerto Rico.

METHODS

A retrospective cross-sectional health records study of DM patients referred by primary care physicians for dilated retinal evaluation to the Inter American University of Puerto Rico School of Optometry Juana Diaz Eye Institute Clinic between 2001 and 2009 was performed. All subjects underwent a complete eye evaluation including fundus photography. Photographs were graded following the Early Treatment Diabetic Retinopathy Study protocols.

RESULTS

A total of 411 randomly selected health records of DM subjects older than 30 years were included. The estimated prevalence of DR among all subjects is 37.7%. DR was more common in males (47.2%) than females (33.7%). The age range with higher frequency of DR is among ages 60 to 69 (34.8%) and the lowest between ages 30 and 39 (3.9%). The average number of years since initial DM diagnosis was 12.48. Probability of developing DR increases with longer duration of DM (p < 0.05). The most common stage was mild non-proliferative DR (22.6%).

CONCLUSIONS

Our data revealed that prevalence of DR was high among Puerto Ricans. Mild stage retinopathy was most prevalent and there exists an increase in probability to develop DR with duration of DM. The prevalence of DR in total population may be different than the findings presented in this paper. Comprehensive studies are needed to understand and estimate the progression and impact of DR in this population.

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.

Disparities in diabetes mellitus among Caribbean populations: a scoping review

Background

Despite the large body of research on racial/ethnic disparities in health, there are limited data on health disparities in Caribbean origin populations. This review aims to analyze and synthesize published literature on the disparities in diabetes mellitus (DM) and its complications among Afro-Caribbean populations.

Methods

A detailed protocol, including a comprehensive search strategy, was developed and used to identify potentially relevant studies. Identified studies were then screened for eligibility using pre-specified inclusion and exclusion criteria. An extraction form was developed to chart data and collate study characteristics including methods and main findings. Charted information was tagged by disparity indicators and thematic analysis performed. Disparity indicators evaluated include ethnicity, sex, age, socioeconomic status, disability and geographic location. Gaps in the literature were identified and extrapolated into a gap map.

Results

A total of 1009 diabetes related articles/manuscripts, published between 1972 and 2013, were identified and screened. Forty-three studies met inclusion criteria for detailed analysis. Most studies were conducted in the United Kingdom, Trinidad and Tobago and Jamaica, and used a cross-sectional study design. Overall, studies reported a higher prevalence of DM among Caribbean Blacks compared to West African Blacks and Caucasians but lower when compared to South Asian origin groups. Morbidity from diabetes-related complications was highest in persons with low socioeconomic status. Gap analysis showed limited research data reporting diabetes incidence by sex and socioeconomic status. No published literature was found on disability status or sexual orientation as it relates to diabetes burden or complications. Prevalence and morbidity were the most frequently reported outcomes.

Conclusion

Literature on diabetes health disparities in Caribbean origin populations is limited. Future research should address these knowledge gaps and develop approaches to reduce them.

Gender difference in the association of metabolic syndrome and its components with age-related cataract: the Korea National Health and Nutrition Examination Survey 2008-2010

Purpose

To explore the relationship of the metabolic syndrome (MetS) and its components with age-related cataract in a representative Korean population.

Methods

We analyzed the data from the Korea National Health and Nutrition Examination Surveys (2008–2010). A total of 11,076 adults (4,811 men and 6,265 women) aged 40 and over who completed ophthalmologic examination were evaluated. Cataract was defined as the presence of cortical, nuclear, anterior (sub)capsular or posterior subcapsular cataract, from slit-lamp examination or previous cataract surgery. MetS was defined according to the Joint Interim Statement proposed in 2009 from the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute.

Results

The prevalence of cataract and MetS in this population was 39.4% (37.1% for men and 41.6% for women) and 38.5% (37.6% for men and 39.4% for women), respectively. Cataract prevalence tended to increase with the number of MetS components in both genders (both P< 0.001). After being controlled for confounders, however, MetS was significantly associated with cataract only in women (adjusted odds ratio (aOR), 1.24; 95% confidence interval (CI), 1.02–1.50]. Reduced HDL cholesterol, elevated fasting glucose, and elevated triglycerides were also significantly associated with cataract in women (aOR, 95% CI; 1.27 (1.07–1.50), 1.23 (1.01–1.50), and 1.26 (1.04–1.52), respectively). In the subgroup analysis for cataract subtype, MetS and reduced HDL cholesterol were significantly associated with nuclear cataract in women (aOR, 95% CI; 1.25 (1.07–1.55) and 1.25 (1.03–1.52), respectively). However, such associations were not found in men.

Conclusions

Our results suggest that MetS and its components appear to be associated with age-related cataract only among Korean women, especially in nuclear cataract.

Current state of care for diabetic retinopathy in India

In this article we review the current state of care of diabetic retinopathy in India. We discuss the magnitude of the problem; diabetes, and diabetic retinopathy in India. We highlight the causes of vision loss in diabetic retinopathy. The current level of awareness among general population and physicians is a concern. Current screening strategies practiced in India and the situational analysis of ophthalmologists in India are also reviewed. We review the current management of diabetic macular edema and proliferative diabetic retinopathy. To know the current practice pattern among retinal surgeons in India, a survey was done and the results of the survey are presented. There are few studies in the Indian population which have found some genetic risk and protective factors and a summary of these studies are also presented in this article.

Lipoprotein(a) serum levels in diabetic patients with retinopathy

BACKGROUND

Atherogenic lipoproteins, such as total cholesterol, LDL cholesterol, oxidized low density lipoprotein, and triglycerides, are associated with progression of retinopathy. Aim. To evaluate the relationship between lipoprotein(a) and retinopathy in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We enrolled 145 diabetic consecutive patients (82 females, 63 males; mean age 66.8 ± 12 years, mean duration of diabetes 9.4 ± 6.8 years). Presence and severity of retinopathy were evaluated. Serum lipid profile, including Lp(a) level, was assessed.

RESULTS

High Lp(a) levels have been observed in 54 (78.3%) subjects and normal levels in 13 (18.85%) subjects as regards diabetic patients with retinopathy. Lp(a) levels were high in 15 subjects (21.75%) and normal in 63 subjects (91.35%) as regards patients without retinopathy.

CONCLUSIONS

Lp(a) levels are increased in a significant percentage of patients with retinopathy compared to diabetic patients without retinopathy. The impact of Lp(a) levels on diabetic retinopathy needs to be further investigated.

Prevalence of diabetic retinopathy in Type 2 diabetes in developing and developed countries

BACKGROUND

As the global prevalence of diabetes increases, so will the numbers of people with diabetic retinopathy. Our review aimed to provide a comprehensive picture of available studies of diabetic retinopathy and how prevalence varies around the developed and developing world.

METHODS

A detailed literature search using PubMed was undertaken. The following search term was used: 'diabetic retinopathy AND prevalence'. The titles and abstracts of all publications identified by the search were reviewed and 492 studies were retrieved. Inclusion and exclusion criteria were applied.

RESULTS

A total of 72 articles from 33 countries were included. There were only 26 population-based studies using fundus photography (12 in developing countries), of which only 16 (eight in developing countries) were published since 2000. Prevalence estimates varied from as low as 10% to as high as 61% in persons with known diabetes and from 1.5 to 31% in newly diagnosed diabetes. Across all the studies, the median (interquartile range) prevalence of any diabetic retinopathy in known diabetes was 27.9% (22-37%) and 10.5% (6-16%) in newly diagnosed diabetes. Prevalence of diabetic retinopathy was higher in developing countries.

CONCLUSION

Significant gaps exist in that reliable population-based data from developing nations and indigenous populations in particular are lacking. Major differences in study characteristics and methodologies make comparisons very difficult. More research is required and study methodologies must be better standardized. This will provide important information for prevention and treatment strategies.

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.

Prevalence and risk factors for diabetic retinopathy: the Beijing Communities Diabetes Study 6

BACKGROUND

To examine prevalence and associated factors of diabetic retinopathy in patients with Type 2 diabetes mellitus in urban communities of Beijing.

METHODS

The community health care center-based study included subjects with diabetes mellitus and an age of 20 years to 80 years, who were recruited from 15 community health centers in urban Beijing. Diabetes mellitus was defined using the World Health Organization criteria. Fundus photographs were graded using the modified Airlie House classification system.

RESULTS

Of 2,642 eligible patients, 2,007 (76.0%) subjects (1,199 women) with a mean age of 64.1 ± 9.0 years participated. The overall prevalence of diabetic retinopathy was 24.7 ± 1.0% (95% confidence interval [CI], 22.8-26.6). In binary logistic analysis, presence of diabetic retinopathy was associated with younger age (odds ratio [OR], 0.97; 95% CI, 0.95-0.98), longer duration of diabetes (OR, 1.10; 95% CI, 1.08-1.12), higher concentration of glycosylated hemoglobin HbA1c (OR, 1.23; 95% CI, 1.14-1.33), higher systolic blood pressure (OR, 1.01; 95% CI, 1.01-1.02), lower body mass index (OR, 0.95; 95% CI, 0.92-0.98), and elevated blood urea concentration (OR, 1.01; 95% CI, 1.00-1.01). Microalbuminuria was an additional associated factor (OR, 1.55; 95% CI, 1.16-2.08). Patients with microalbuminuria were 4.7 times more likely to have a severe or proliferating diabetic retinopathy than those without microalbuminuria.

CONCLUSION

In the urban population of Beijing, prevalence of diabetic retinopathy in diabetic patients was 25%. As in whites, increased blood pressure besides elevated plasma glucose concentrations was highly significantly associated with diabetic retinopathy in Chinese. It suggests that in Chinese as also in whites, blood pressure control beside control of plasma glucose levels is important to prevent development or progression of diabetic retinopathy.

Surgical and visual outcome following 20-gauge vitrectomy in proliferative diabetic retinopathy over a 10-year period, evidence for change in practice

INTRODUCTION

The study reports 10-year anatomical and visual outcome in patients who underwent pars plana vitrectomy (PPV) for complications due to proliferative diabetic retinopathy (PDR).

METHODS

Retrospective analysis of patients undergoing 20 G PPV from January 1999 to May 2010 for tractional retinal detachment (TRD) and non-clearing vitreous hemorrhage (NCVH) secondary to PDR recorded prospectively on an electronic patient record. The primary aim was to study anatomical success and eyes with visual acuity (VA) of ≤ 0.3 logMAR at last follow-up.

RESULTS

There were 346 eyes of 249 patients with mean age of 55.63 years and follow-up of 1.44 years. In all, 95.3% of eyes had a flat retina at final follow-up. Overall 136/346 (39.4%) eyes had final VA of logMAR ≤ 0.3 (Snellen 6/12) and 129 (37.3%) had logMAR ≥ 1.0 (Snellen 6/60). In all, 50/181 (27.6%) eyes with TRD and 84/165 (50.9%) with NCVH achieved final VA of ≤ 0.3 logMAR (Snellen 6/12). A total of 218 (63.1%) showed ≥ 0.3 logMAR improvement from baseline to last follow-up. Both preoperative VA and final postoperative (post-op) VA (P<0.001) improved significantly with each year from 1999 to 2010. The commonest peroperative complication was iatrogenic retinal tear formation (28.4%). This was a risk factor for the development of post-op retinal detachment, odds ratio: 3.90 (95% confidence interval: 1.91-7.97, P = 0.0002). Silicone oil was used in 5.2% of patients at the primary procedure. In all, 9.2% required removal of non clearing post vitrectomy hemorrhage.

CONCLUSIONS

Outcomes from vitreoretinal surgery for complications of diabetic retinopathy have improved. In addition, the visual outcome after diabetic vitrectomy steadily improved over the 10-year period, which may in part be due to the move to operate on patients with better vision.

Retinopathy among type 2 diabetic patients seen at a tertiary hospital in Nigeria: a preliminary report

Objective

To determine the prevalence of diabetic retinopathy among patients attending the diabetic clinics of a tertiary hospital in Nigeria.

Methodology

We examined the eyes of 76 patients with type 2 diabetes mellitus between July 2003 and January 2004 using dilated fundoscopy at the eye clinic of the University College Hospital, Ibadan. The results were compared with published figures.

Results

Mean age of patients was 57.5 ± 10.4 years. Thirty–two patients (42.1%) had diabetic retinopathy. Of these, one patient had features of proliferative diabetic retinopathy while the other patients had non-proliferative diabetic retinopathy. Majority (53.1%) of those who had retinopathy had diabetes for more than 10 years, while 21.4% of patients without retinopathy had diabetes for more than 10 years (p = 0.005). The mean serial post-prandial plasma glucose of those who had retinopathy was higher when compared with the mean for those who did not have retinopathy (248.7 mg/dl vs 178.3 mg/dl; p = 0.003).

Conclusion

The prevalence of diabetic retinopathy in our patients is higher than was previously reported in earlier studies. Patients with diabetes ought to be referred for ophthalmological evaluation and follow-up which they should be actively encouraged to attend.

15-year cumulative incidence and associated risk factors for retinopathy in nondiabetic persons

OBJECTIVE

To investigate the relationship of systemic factors to the 15-year cumulative incidence of retinopathy in nondiabetic persons in the Beaver Dam Eye Study.

METHODS

Included were 4699 persons, 43 to 86 years of age at baseline examination in 1988-1990 and with follow-up in 1993-1995 and/or 1998-2000 and/or 2003-2005. Stereoscopic color fundus photographs were graded to determine the presence of retinopathy. The main outcome measure was cumulative incidence of retinopathy accounting for competing risk of death or diabetes mellitus.

RESULTS

The 15-year cumulative incidence of retinopathy in the nondiabetic cohort was 14.2%. In multivariate analyses, older age (hazard ratio [HR] per age group, 1.13; 95% confidence interval [CI], 1.01-1.27), higher systolic blood pressure (HR per 10 mm Hg, 1.15; 95% CI, 1.07-1.20), presence of chronic kidney disease (HR, 1.51; 95% CI, 1.12-2.00), and wider retinal arteriolar diameter (HR per 10 μm, 1.17; 95% CI, 1.10-1.26) at baseline were associated with the incidence of retinopathy. In a separate model, the 15-year incidence of retinopathy was higher in those with uncontrolled hypertension compared with those who did not have hypertension (HR, 2.07; 95% CI, 1.51-2.83). There were no associations of body mass index, lipid levels, glycosylated hemoglobin level, smoking status, markers of inflammation, endothelial dysfunction and oxidative stress, and hematologic factors with retinopathy incidence.

CONCLUSIONS

These data show 2 modifiable factors, uncontrolled hypertension and chronic kidney disease, are related to an increased incidence of retinopathy in nondiabetic persons and show that control of blood pressure is associated with a lower risk of incident retinopathy compared with uncontrolled blood pressure.

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.

Prediction of incident stroke events based on retinal vessel caliber: a systematic review and individual-participant meta-analysis

The caliber of the retinal vessels has been shown to be associated with stroke events. However, the consistency and magnitude of association, and the changes in predicted risk independent of traditional risk factors, are unclear. To determine the association between retinal vessel caliber and the risk of stroke events, the investigators combined individual data from 20,798 people, who were free of stroke at baseline, in 6 cohort studies identified from a search of the Medline (National Library of Medicine, Bethesda, Maryland) and EMBASE (Elsevier B.V., Amsterdam, the Netherlands) databases. During follow-up of 5-12 years, 945 (4.5%) incident stroke events were recorded. Wider retinal venular caliber predicted stroke (pooled hazard ratio = 1.15, 95% confidence interval: 1.05, 1.25 per 20-micron increase in caliber), but the caliber of retinal arterioles was not associated with stroke (pooled hazard ratio = 1.00, 95% confidence interval: 0.92, 1.08). There was weak evidence of heterogeneity in the hazard ratio for retinal venular caliber, which may be attributable to differences in follow-up strategies across studies. Inclusion of retinal venular caliber in prediction models containing traditional stroke risk factors reassigned 10.1% of people at intermediate risk into different, mostly lower, risk categories.

Nine-year incidence of visual impairment in the Barbados Eye Studies

OBJECTIVE

To describe the 9-year incidence of visual impairment and primary causes of blindness among black participants of the Barbados Eye Studies (BES).

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

The BES followed a nationally representative cohort selected by simple random sampling, aged 40 to 84 years at baseline, with reexaminations after 4 years (Barbados Incidence Study of Eye Diseases [BISED]) and 9 years (BISED II). BISED II included 2793 (81%) of those eligible.

METHODS

Cumulative 9-year incidence rates were estimated by the Product-Limit approach. The study was reviewed and approved by the institutional review boards of collaborating institutions.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (VA) was assessed by the Ferris-Bailey chart, following a modified Early Treatment of Diabetic Retinopathy Study protocol. Low vision and blindness were defined by World Health Organization (WHO) criteria as VA <6/18 to 6/120, and <6/120, respectively, in the better eye, and by U.S. criteria as VA < or =20/40 and < or =20/200, respectively. Vision loss was defined as a decrease of 15 letters or more read correctly in the better eye between baseline and follow-up examinations.

RESULTS

The 9-year incidence was 1.0% and 2.1% for blindness and 6.0% and 9.0% for low vision, by WHO and U.S. criteria, respectively. Older age at baseline was associated with higher incidence of low vision and blindness, reaching 23.0% (95% confidence interval [CI], 18.8-28.0) and 4.3% (95% CI, 2.7-6.9) at age 70 years or more, based on WHO criteria. The primary causes of incident bilateral blindness (U.S. criteria) in 126 eyes were age-related cataract (48.3%), open-angle glaucoma (OAG) (14.3%), combined cataract and OAG (6.3%), diabetic retinopathy (8.7%), and optic atrophy (7.1%). Age-related macular degeneration (2.4%) rarely caused blindness.

CONCLUSIONS

Incident visual impairment is exceedingly high in this population. Cataract, OAG, and diabetic retinopathy remain the major causes of blindness, underpinning the clinical and public health significance of these conditions in this and similar populations.

Prevalence of diabetic retinopathy in rural China: the Handan Eye Study

PURPOSE

To describe the age- and gender-specific prevalence, characteristics, and severity of diabetic retinopathy (DR) in a rural population in northern China.

DESIGN

A population-based cross-sectional study.

PARTICIPANTS

A total of 6830 Han Chinese aged 30 years and older from 13 villages of Yongnian County, Handan City, Hebei Province, China.

METHODS

All participants underwent a standardized interview, a comprehensive eye examination, and fasting blood glucose testing according to the American Diabetes Association diagnostic criteria (fasting plasma glucose >or=7.0 mmol/l). Retinal photographs obtained after pupil dilation were graded for the presence and severity of DR according to the modified Early Treatment Diabetic Retinopathy Study classification system.

MAIN OUTCOME MEASURES

Any DR, retinopathy grades, macular edema, or vision-threatening retinopathy.

RESULTS

Of the 6830 eligible individuals participating in the study, 5597 (81.9%) had fasting blood glucose results available. Of these, 387 participants (6.9%) were diagnosed with diabetes mellitus, including 247 subjects with new diabetes mellitus (NDM) and 140 subjects with known diabetes mellitus (KDM). For these, gradable photographs were available for 368 subjects (95.1%). The overall prevalence of DR was 43.1% (95% confidence interval, 38.1-48.4) and was higher in persons with KDM (65.2%) than NDM (33.5%). The prevalence of proliferative DR, macular edema, and vision-threatening retinopathy was 1.6%, 5.2%, and 6.3%, respectively, with 12.1% with KDM having untreated vision-threatening DR. No age- or gender-related differences were present. The prevalence of DR was strongly related to duration of disease.

CONCLUSIONS

Our study reports a high prevalence of DR among adults 30 years and older with diabetes in rural China. On the basis of estimates obtained from our study, we projected that in rural China, 21.1 million persons aged 30+ years have diabetes and 9.2 million have DR, including 1.3 million with vision-threatening DR. There is a pressing need for appropriate screening and management of diabetes and its complications in rural China.

Prevalence of diabetic retinopathy in India: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study report 2

OBJECTIVE

The aim of the study was to estimate the prevalence of diabetic retinopathy in an urban Indian population older than 40 years.

DESIGN

A population-based cross-sectional study.

PARTICIPANTS

Five thousand nine hundred ninety-nine subjects residing in Chennai, India, were enumerated.

METHODS

A multistage random sampling, based on socioeconomic criteria, was followed. Identified subjects with diabetes mellitus (based on the World Health Organization criteria) underwent detailed examination at the base hospital. The fundi of all patients were photographed using 45 degrees , 4-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on Klein's classification of the Early Treatment Diabetic Retinopathy Study scale.

MAIN OUTCOME MEASURES

These included age- and gender-adjusted prevalence of diabetes and diabetic retinopathy, and correlation of prevalence with history-based risk factors.

RESULTS

The age- and gender-adjusted prevalence rate of diabetes in an urban Chennai population was 28.2% (95% confidence interval [CI], 27.0-29.3), and the prevalence of diabetic retinopathy in general population was 3.5% (95% CI, 3.49-3.54). The prevalence of diabetic retinopathy in the population with diabetes mellitus was 18.0% (95% CI, 16.0-20.1). History-based variables that were significantly associated with increased risk of diabetic retinopathy included gender (men at greater risk; odds ratio [OR], 1.41; 95% CI, 1.04-1.91); use of insulin (OR, 3.52; 95% CI, 2.05-6.02); longer duration of diabetes (>15 years; OR, 6.43; 95% CI, 3.18-12.90); and subjects with known diabetes mellitus (OR, 2.98; 95% CI, 1.72-5.17). Differences in the socioeconomic status did not influence the occurrence of diabetic retinopathy.

CONCLUSIONS

The prevalence of diabetic retinopathy was 18% in an urban population with diabetes mellitus in India. The duration of diabetes is the strongest predictor for diabetic retinopathy.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Awareness of Incident Open-angle Glaucoma in a Population Study

PURPOSE

To evaluate factors related to awareness of incident open-angle glaucoma (OAG) in the Barbados Eye Studies.

DESIGN

Cohort study with 81% to 85% response rate over 9 years.

PARTICIPANTS

Four thousand three hundred fourteen participants of African descent, 40 to 84 years old at baseline.

METHODS

Standardized study visits included an interview on demographic, medical, health care, and other factors; various ophthalmic measurements; fundus photography; and comprehensive ophthalmologic examinations for those referred.

MAIN OUTCOME MEASURES

Definite OAG was defined by both visual field and optic disc criteria after ophthalmologic confirmation, regardless of intraocular pressure (IOP). Definite incident participants without prior OAG diagnosis/treatment were considered unaware. Logistic regression analyses evaluated factors associated with OAG unawareness. Results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Over 9 years, 125 participants newly developed definite OAG, of whom 53% were previously unaware. At baseline, the unaware group had significantly lower mean IOP (OR, 0.86; 95% CI, 0.79-0.94) and more hyperopia (OR, 2.69; 95% CI, 1.08-6.69) than those aware. Most unaware and aware participants had > or =2 medical care visits in the previous year (72.7% vs. 83.1%). However, those in the unaware group sought eye care less frequently than those aware (last visit in preceding year, 33.4% vs. 64.4%); these visits were mainly for eyeglasses (71.4% vs. 12.5%), with most having glaucoma tests only during study visits (72.7% vs. 37.3%). The unaware group reported more visits to opticians/optometrists than to private ophthalmologists (OR, 4.20; 95% CI, 1.00-17.66) and fewer visits to a public ophthalmologic clinic (OR, 0.18; 95% CI, 0.04-0.86).

CONCLUSIONS

Over half of participants with incident OAG were unaware of their diagnosis. Unawareness was related to lower IOP, hyperopia, and eye care utilization patterns. Although persons in the unaware group had regular visits for medical care, visits for eye care and OAG testing were limited. Unawareness was 4 times more likely when opticians/optometrists were the regular eye care source, compared with private ophthalmologists, and about 80% less likely with a public ophthalmologic source. These findings highlight the high frequency of undiagnosed OAG and importance of comprehensive examinations in disease detection.

Ophthalmologic disorders in minority populations

Race- and ethnicity-related differences in prevalence of a number ofophthalmologic disorders have been documented. More importantly, blackand Hispanic Americans share a disproportionate share of morbidity, asmeasured by visual impairment and blindness, when compared with whiteAmericans. The reasons for this health disparity are complex andmultifactorial. If the unequal, individual, and societal burden of avoidable vision lossamong black and Hispanic Americans is to be decreased, it is essential tounderstand the apparent barriers to accessing timely and appropriateophthalmologic monitoring and care for these minority populations. Forthose who do gain access to ophthalmologic care, it is important tounderstand better the determinants leading to different treatment of blackand Hispanic Americans compared with white Americans. Opportunities for decreasing vision-related morbidity caused by cataract,diabetic retinopathy, and glaucoma for these minority groups clearly exist. Strategies for each of these ophthalmologic disorders may differ. Cataract isa reversible cause of visual impairment and removal of cataract improvesquality of life. Cataract surgery should be offered to all who can potentiallybenefit from this treatment. Earlier diagnosis, before the disease hasprogressed to loss of vision, should be a goal in both glaucoma and diabeticretinopathy. Strategies for screening high-risk groups may be particularlyrelevant in this regard. Additionally, with diabetic retinopathy, improvedmanagement of contributing risk factors, such as blood glucose control andblood pressure control, is important. Asian Americans are increasingly becoming a sizable minority group inthe United States. It is projected that by 2070, the Asian population willreach 11% of the total population of the United States. Virtually all of thepopulation-based data relating to ophthalmologic disorders in Asians havebeen performed in Asia. The reported relative proportion of PACG versusPOAG, however, among some Asian populations and of normal-tensionglaucoma versus high-tension glaucoma among the Japanese seems to applyto the United States Asian population. This assertion is based onwidespread clinical impression and analysis of Medicare claims data [56]. Understanding the differences is important for optimal treatment of theseminority populations as the proportion of Asians in the United Statescontinues to grow. The common denominator in all of these diseases is the role of thephysician and patient. Educational programs aimed at the physician tofacilitate cultural competence and at the patient to increase level of knowledgeabout their disease are appropriate and enthusiastically endorsed.

Visual dysfunction after panretinal photocoagulation in patients with severe diabetic retinopathy and good vision

PURPOSE

To compare macular thickness and best-corrected visual acuity (BcVA) before and after panretinal photocoagulation (PRP) in patients with severe diabetic retinopathy and good visual acuity (VA) to identify factors that predict post-operative visual function.

DESIGN

Prospective, non-comparative, interventional case series.

METHODS

Sixty-four consecutive patients with severe non-proliferative diabetic retinopathy or with non-high-risk proliferative diabetic retinopathy whose VA was 20/20 or better before PRP were studied. Sixty-four eyes of 64 patients underwent scatter PRP in four sessions every other week. Macular thickness was measured by optical coherence tomography (OCT), and VA was measured before and periodically after PRP.

RESULTS

During the 24-week observation period, patients were classified into three groups according to changes in VA during the post-operative period. In group A, VA was maintained at pre-operative levels in 54 (84%) eyes during the 24 weeks after PRP. In group B, VA initially decreased in three eyes but subsequently recovered to baseline during the observation period; in group C, VA did not recover during follow-up in seven eyes. There was no significant difference in pre-operative foveal thicknesses among the three groups, but parafoveal thickness was <260 mum in group A, ranged from 270 to 280 mum in group B, and was >300 mum in group C.

CONCLUSION

For eyes with severe diabetic retinopathy and good VA, PRP did not affect post-operative VA in more than 80% of patients. Patients whose pre-operative parafoveal thickness was >300 mum had a worse visual prognosis.

Prevalence of retinopathy in Caucasian type 2 diabetic patients from the South of Brazil and relationship with clinical and metabolic factors

Diabetic retinopathy (DR) is a sight-threatening chronic complication of diabetes mellitus and is the leading cause of acquired blindness in adults. In this cross-sectional study, we investigated the prevalence of and the factors associated with DR in an analysis of 210 consecutive and unrelated Brazilian Caucasians with type 2 diabetes mellitus. Retinopathy was evaluated by ophthalmoscopy and/or biomicroscopy through dilated pupils. The relationship between clinical and metabolic variables and the presence of DR was assessed by logistic regression analysis. DR was detected in 99 of the 210 patients (47%). In the univariate logistic regression analyses, male sex, duration of diabetes, body mass index, glycated hemoglobin, C-peptide, LDL cholesterol, smoking, and albumin excretion rate were found to be associated with the presence of DR. However, the multiple logistic regression analysis showed that only duration of diabetes (odds ratio (OR) = 1.15, 95% CI = 1.09-1.22; P < 0.001), glycated hemoglobin (OR = 1.21, 95% CI = 1.01-1.46; P = 0.047) and albumin excretion rate > 100 microg/min (OR = 12.72, 95% CI = 3.89-41.56; P < 0.001) were independently associated with DR. Although DR was found to be frequent among Brazilian type 2 diabetic patients, its prevalence was within the range observed in other Caucasian populations. Our findings emphasize the need for good glycemic control in order to prevent or delay the onset of DR, since the most well-known risk factors for the development of this complication in type 2 diabetes mellitus, such as duration of diabetes, glycated hemoglobin and albumin excretion rate were independently related to DR.

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.

Prevalence of diabetic retinopathy in adult Latinos

OBJECTIVE

To estimate age- and gender-specific prevalence of diabetic retinopathy (DR) and to determine the association of type, duration, and treatment of diabetes with the prevalence of DR in adult Latinos.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Six thousand three hundred fifty-seven Latinos aged 40 years and older from 6 census tracts in Los Angeles, California.

METHODS

The study cohort consisted of all self-identified Latinos of primarily Mexican ancestry aged 40 years and older residing in 6 census tracts in La Puente, Los Angeles County, California. All participants diagnosed with diabetes underwent a complete ophthalmologic examination, including stereoscopic fundus photography (7 standard Early Treatment Diabetic Retinopathy Study fields). Photographs were graded in a masked manner using a modified Airlie House Grading System to assess presence and severity of DR.

MAIN OUTCOME MEASURES

Prevalence of nonproliferative DR, proliferative DR, and macular edema.

RESULTS

Of 1263 participants with definite diabetes mellitus, gradable fundus photographs were available in 1217 participants (96%). Of those 1217 participants, 46.9% had DR. Severe nonproliferative DR and proliferative DR were present in 4.4% and 6.1% of diabetics, respectively. Macular edema was observed in 10.4% and clinically significant macular edema was observed in 6.2% of all diabetics. No age- or gender-related differences were present. After adjusting for duration of diabetes, the prevalence of DR was similar in persons with type 1 and type 2 diabetes.

CONCLUSIONS

Our data suggest that the prevalence of DR is high among Latinos of primarily Mexican ancestry. The increase in prevalence of DR with longer duration of diabetes emphasizes the public health importance of early diagnosis and management in Latinos. Further data on incidence and progression are required to understand better the natural history of DR in Latinos.

Four-year incidence of visual impairment: Barbados Incidence Study of Eye Diseases

OBJECTIVE

To describe the 4-year incidence of visual impairment and causes of blindness among black participants of the Barbados Eye Studies.

DESIGN

Population-based incidence study.

SETTING AND PARTICIPANTS

The Barbados Incidence Study of Eye Diseases (BISED) followed the cohort of the Barbados Eye Study (BES), a prevalence study based on a simple random sample of Barbadians 40 to 84 years of age. BISED included 3193 black participants from the original cohort (85% of those eligible).

MAIN OUTCOME MEASURES

Best-corrected visual acuity (Ferris-Bailey chart) at baseline and follow-up was measured according to a modified Early Treatment of Diabetic Retinopathy Study protocol. By use of World Health Organization (WHO) criteria, low vision and blindness for an individual were defined as visual acuity (VA) <6/18 to 6/120 and <6/120, respectively, in the better eye. By commonly used US criteria, low vision and blindness were defined as VA < or = 20/40 and < or = 20/200, respectively. Vision loss was defined as a doubling of the visual angle (i.e., decrease of 15 letters or more read correctly between baseline and follow-up examinations). Progression was defined as vision loss among those with low vision at baseline.

RESULTS

On the basis of WHO criteria, the overall 4-year incidence was 3.6% (95% confidence interval [CI], 3.0%-4.4%) for low vision and 0.6% (95% CI, 0.4%-1.0%) for blindness. Incidence rates were higher using US criteria: 5.3% (95 % CI, 4.5%-6.2%) and 1.5% (95% CI, 1.1%-2.0%), respectively, reaching 21.5% and 7.3% for persons aged 70 years or older at baseline. One tenth of the cohort had vision loss, and 28.6% of those with low vision progressed. About one half of incident blindness was due to age-related cataract. Nearly one fifth was caused by open-angle glaucoma (OAG) alone or combined with cataract, and approximately 10% was caused by diabetic retinopathy (DR).

CONCLUSIONS

The incidence of visual impairment was high in this Afro-Caribbean population, particularly in older age groups, indicating the public health significance of visual loss for this and similar black populations. Cataract, OAG, and DR were among the leading causes of incident blindness, paralleling their high prevalence in this population.

Diabetic retinopathy in Euro-Brazilian type 2 diabetic patients: relationship with polymorphisms in the aldose reductase, the plasminogen activator inhibitor-1 and the methylenetetrahydrofolate reductase genes

We investigated the relationship between diabetic retinopathy (DR) and three polymorphisms, C(-106)T in the aldose reductase (ALR2) gene, 4G/5G in the plasminogen activator inhibitor-1 (PAI-1) gene and C677T in the methylenetetrahydrofolate reductase (MTHFR) gene, in 210 Euro-Brazilian type 2 diabetic patients. Retinopathy was evaluated by funduscopic examination and genotype analysis was performed using the polymerase chain reaction and allele-specific restriction. Retinopathy was detected in 47% of the patients. There were no significant differences in allele or genotype distributions between patients with or without retinopathy for all polymorphisms. Thus, the three polymorphisms are not related to the presence of DR in Euro-Brazilian type 2 diabetic patients.

Incidence of diabetic retinopathy in the Barbados Eye Studies

PURPOSE

To examine the 4-year incidence and risk factors for diabetic retinopathy (DR) among black participants with diabetes in the Barbados Eye Studies (BES).

DESIGN

Population-based incidence study.

SETTING AND PARTICIPANTS

Four hundred ten persons with diabetes mellitus (DM) from the BES cohort, which was based on a simple random sample of Barbadians, 40 to 84 years of age at baseline.

MAIN OUTCOME MEASURES

Development of DR, assessed by independent gradings of 30 degrees color stereo fundus photographs of the disc and macula. Associations were evaluated by logistic regression analyses.

RESULTS

After 4 years, DR developed in 92 of 306 (30.1%; 95% confidence interval, 25.0%, 35.5%) persons unaffected at baseline. The incidence of DR was 31.9% in those with known DM at baseline and 20.9% in newly diagnosed DM. Clinically significant macular edema developed in 16 (4.5%) of 353 individuals at risk. Seven (6.9%) of the 101 persons with minimum or moderate DR at baseline progressed to proliferative DR. Age-specific incidence declined from 36.2% at age 40 to 49 years to 28.8% and 24.2% over the subsequent two decades, increasing to 38.2% among those >/=70 years. Risk factors for DR were increased systolic blood pressure (relative risk [RR], 1.16 [1.03, 1.31]/10 mmHg increase); use of oral hypoglycemics (RR, 2.4 [1.3, 4.2]); and use of insulin (RR, 6.1 [1.7, 22.1]) (vs. no treatment or diet only); and elevated glycated hemoglobin (GHb; RR, 6.4 [2.5, 16.0]); GHb >11.5% vs. GHb </=8%).

CONCLUSIONS

High rates of incident DR were evident in the black BES population, also known to have high rates of DM. Prevention of visual loss caused by DR in this population has high priority, including optimal glycemic and blood pressure control.

Eye disease and care in Latin America and the Caribbean

In the last decade, health indicators in Latin America and the Caribbean reflect advances. The per capita public expenditure on health care has increased in many countries. Despite these improvements, it is estimated that for every million population in Latin America and the Caribbean, 5,000 are blind and 20,000 are visually impaired; at least 66% of the blindness is attributable to treatable conditions such as cataract. The cataract surgery rate in the region remains low as compared to the industrialized countries, although it is higher than many other regions of the world. The availability of eye care services varies from country to country within the region, and the number of ophthalmologists per million population in the richest countries may be nine times more than in the poorest. Access, defined as the distance between the consumer and the services, is problematic in countries with isolated areas in the rainforest or high mountains, poor road systems, or lack of public transportation. Affordability is an important issue that limits utilization of services by the poorest segments of the population in nearly all countries in Latin America and the Caribbean.