The epidemiology of diabetes complications study. IV. Correlates of diabetic background and proliferative retinopathy

Diabetic Retinopathy Screening at the Point of Care (DR SPOC): detecting undiagnosed and vision-threatening retinopathy by integrating portable technologies within existing services

INTRODUCTION

The aim of this study was to determine the prevalence of diabetic retinopathy (DR) in a low socioeconomic region of a high-income country, as well as determine the diagnostic utility of point-of-care screening for high-risk populations in tertiary care settings.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study of patients with diabetes attending foot ulcer or integrated care diabetes clinics at two Western Sydney hospitals (n=273). DR was assessed using portable, two-field, non-mydriatic fundus photography and combined electroretinogram/ pupillometry (ERG). With mydriatic photographs used as the reference standard, sensitivity and specificity of the devices were determined. Prevalence of DR and vision-threatening diabetic retinopathy (VTDR) were reported, with multivariate logistic regression used to identify predictors of DR.

RESULTS

Among 273 patients, 39.6% had any DR, while 15.8% had VTDR, of whom 59.3% and 62.8% were previously undiagnosed, respectively. Non-mydriatic photography demonstrated 20.2% sensitivity and 99.5% specificity for any DR, with a 56.7% screening failure rate. Meanwhile, mydriatic photography produced high-quality images with a 7.6% failure rate. ERG demonstrated 72.5% sensitivity and 70.1% specificity, with a 15.0% failure rate. The RETeval ERG was noted to have an optimal DR cut-off score at 22. Multivariate logistic regression identified an eGFR of ≤29 mL/min/1.73 m2, HbA1c of ≥7.0%, pupil size of <4 mm diameter, diabetes duration of 5-24 years and RETeval score of ≥22 as strong predictors of DR.

CONCLUSION

There is a high prevalence of vision-threatening and undiagnosed DR among patients attending high-risk tertiary clinics in Western Sydney. Point-of-care DR screening using portable, mydriatic photography demonstrates potential as a model of care which is easily accessible, targeted for high-risk populations and substantially enhances DR detection.

Clinical Characteristics and Surgical Outcomes of Complications of Proliferative Diabetic Retinopathy in Young versus Older Patients with Type 2 Diabetes

PURPOSE

Proliferative diabetic retinopathy (PDR) is a leading vision-threatening disease. In this study, we investigated the clinical features of PDR and the surgical outcomes of its complications in patients with type 2 diabetes (T2D).

PATIENTS AND METHODS

We retrospectively reviewed the medical data of patients with T2D who underwent vitrectomy for PDR between January 2016 and June 2021. The patients were divided into two groups by age (young patients, < 45 years; older patients, ≥ 45 years).

RESULTS

There were 149 eyes (100 patients) in the young patient group and 315 eyes (256 patients) in the older patient group. The proportion of males and the proportion of patients requiring binocular surgery were much higher in the young patient group than in the older patient group (P = 0.005 and P < 0.001, respectively). In the young patient group, 26.2% of eyes had active fibrovascular proliferation compared with only 11.4% in the older patient group (P < 0.001). The final best-corrected visual acuity (BCVA) was significantly improved relative to the preoperative BCVA in both groups (P < 0.001). After surgery, there were no significant differences in the incidence of postoperative neovascular glaucoma (NVG) or recurrent vitreous hemorrhage (VH) between the two groups. The incidence of postoperative recurrent retinal detachment was higher in the young patient group (P = 0.033). The risk factors associated with the visual outcomes in the young patient group included preoperative BCVA (P < 0.001), renal diseases (P = 0.001), postoperative NVG (P < 0.001), and recurrent VH (P = 0.028).

CONCLUSION

In this retrospective study, young patients who underwent vitrectomy for PDR had more severe clinical characteristics before vitrectomy. However, vitrectomy (combined with cataract surgery when necessary) achieved better final visual outcomes in young patients than in older patients with T2D.

Urine protein: Urine creatinine ratio correlation with diabetic retinopathy

Purpose

To investigate the urine protein (UP) and urine creatinine (UC) ratio in diabetes mellitus and report its influence as a risk factor for the presence and severity of diabetic retinopathy (DR).

Methods

In total, 150 diabetic patients presenting to the outpatient department were included. Detailed history with informed consent and ophthalmic examination, including visual assessment, external ocular examination, anterior segment evaluation, dilated fundus examination by slit-lamp biomicroscopy, and indirect ophthalmoscopy, was done. The early morning spot urine sample was used to determine spot urine protein creatinine ratio. Association with hypertension, fasting blood sugar (FBS), and HBA1C (glycosylated Hb) were also noted.

Results

Urinary PCR increased with the severity of the diabetic retinopathy (P < 0.001). HbA1c, FBS, and duration of diabetes had a direct correlation with urine PCR. ROC curve analysis showed that the optimal PCR cut-off value for predicting the risk of onset DR was 0.65. Retinopathy progressed with increasing urine PCR. Spot urine PCR strongly correlates with stages of diabetic retinopathy and proteinuria measured in 24-h urine samples.

Conclusion

The study showed that urine PCR can be a marker for risk and progression of diabetic retinopathy.

Metabolite biomarkers of type 2 diabetes mellitus and pre-diabetes: a systematic review and meta-analysis

BACKGROUND

We aimed to explore metabolite biomarkers that could be used to identify pre-diabetes and type 2 diabetes mellitus (T2DM) using systematic review and meta-analysis.

METHODS

Four databases, the Cochrane Library, EMBASE, PubMed and Scopus were selected. A random effect model and a fixed effect model were applied to the results of forest plot analyses to determine the standardized mean difference (SMD) and 95% confidence interval (95% CI) for each metabolite. The SMD for every metabolite was then converted into an odds ratio to create an metabolite biomarker profile.

RESULTS

Twenty-four independent studies reported data from 14,131 healthy individuals and 3499 patients with T2DM, and 14 included studies reported 4844 healthy controls and a total of 2139 pre-diabetes patients. In the serum and plasma of patients with T2DM, compared with the healthy participants, the concentrations of valine, leucine, isoleucine, proline, tyrosine, lysine and glutamate were higher and that of glycine was lower. The concentrations of isoleucine, alanine, proline, glutamate, palmitic acid, 2-aminoadipic acid and lysine were higher and those of glycine, serine, and citrulline were lower in prediabetic patients. Metabolite biomarkers of T2DM and pre-diabetes revealed that the levels of alanine, glutamate and palmitic acid (C16:0) were significantly different in T2DM and pre-diabetes.

CONCLUSIONS

Quantified multiple metabolite biomarkers may reflect the different status of pre-diabetes and T2DM, and could provide an important reference for clinical diagnosis and treatment of pre-diabetes and T2DM.

Characteristics and outcomes of vitrectomy for proliferative diabetic retinopathy in young versus senior patients

Background

Proliferative diabetic retinopathy (PDR) is one of the most common cause of vision loss in diabetic patients, and the incidence age of PDR patients gradually gets younger. This study aims to compare the characteristics of PDR and outcomes following vitrectomy in young and senior patients.

Methods

This is a retrospective case series study. Data of 116 eyes of 92 patients who underwent vitrectomy for PDR from February 2012 to February 2017 were reviewed, which were divided into young and senior patient groups. All patients were followed up for 24 months at least.

Results

There were 62.1% of eyes with tractional retinal detachment secondary to PDR in the young patient group, while only 12.1% of eyes in the senior patient group with this surgery indication. (P < 0.001) The best corrected visual acuity increased in 41 eyes (70.7%), stable in 9 eyes (15.5%), and decreased in 8 eyes (13.8%) in young patients at the final follow-up. And it increased in 47 eyes (81.0%), stable in 2 eyes (3.4%), and decreased in 9 eyes (15.5%) in senior patients.(P = 0.085) Postoperative complications mainly included recurrent vitreous hemorrhage (24.1%), retinal detachment (3.4%), neovascular glaucoma (NVG) (27.6%) and nuclear sclerosis (53.4%) in young patients, and it was 19.0, 0.0, 1.7 and 3.4% in senior patients respectively.

Conclusion

PDR of young patients is more severe than that of senior patients, and vitrectomy is an effective and safe method for PDR treatment. NVG is a main and severe complication besides nuclear sclerosis in young patients, and the incidence of NVG is higher compared to that in senior patients.

Integrated biomarker for type 2 diabetes mellitus and impaired fasting glucose based on metabolomics analysis using ultra-high performance liquid chromatography quadrupole-Orbitrap high-resolution accurate mass spectrometry

RATIONALE

The prevalence of type 2 diabetes mellitus (T2DM) is increasing but its early diagnosis in high risk populations remains challenging using only fasting blood glucose (FBG) or hemoglobin A1c measurements. It is, therefore, important to search for an integrated biomarker for early diagnosis by determining metabolites associated with the progression of the disease.

METHODS

We recruited 149 participants (51 T2DM patients, 50 individuals with impaired fasting glucose (IFG) and 48 normal glucose tolerance subjects). Their serum samples were analyzed based on a metabolomics approach using ultra-high-performance liquid chromatography quadrupole-Orbitrap high-resolution accurate mass spectrometry (UHPLC/Q-Orbitrap HRMS). The changes in metabolites were profiled and evaluated using univariate and multivariate analyses. Furthermore, a biomarker model was established and the potential biomarkers were evaluated using binary logistic regression analysis and receiver operating characteristic analysis with AUC (area under the curve). Pathway analysis of differential metabolites was performed to reveal the important biological information.

RESULTS

Thirty-eight differential metabolites were identified as significantly associated with T2DM patients and 23 differential metabolites with IFG individuals, mainly amino acids, carnitines, and phospholipids. By evaluating 17 potential biomarkers, we defined a novel integrated biomarker consisting of 2-acetolactate, 2-hydroxy-2,4-pentadienoate, L-arabinose and L-glutamine. The AUCs of the integrated biomarker with IFG and T2DM patients were 0.874 and 0.994, respectively, which showed a superior diagnostic performance. The levels of 2-acetolactate and 2-hydroxy-2,4-pentadienoate were strongly positively correlated with FBG, while L-glutamine and L-arabinose were strongly negatively associated with FBG. After pathway analysis, it was suggested that the majority of the influenced metabolic pathways associated with diabetes referred to amino acid metabolism.

CONCLUSIONS

The integrated biomarker could diagnose IFG and T2DM with a superior diagnostic performance. This finding provides support for novel biomarkers in the diagnosis and treatment of diabetes.

Potential Interplay between Hyperosmolarity and Inflammation on Retinal Pigmented Epithelium in Pathogenesis of Diabetic Retinopathy

Diabetic retinopathy is a frequent eyesight threatening complication of type 1 and type 2 diabetes. Under physiological conditions, the inner and the outer blood-retinal barriers protect the retina by regulating ion, protein, and water flux into and out of the retina. During diabetic retinopathy, many factors, including inflammation, contribute to the rupture of the inner and/or the outer blood-retinal barrier. This rupture leads the development of macular edema, a foremost cause of sight loss among diabetic patients. Under these conditions, it has been speculated that retinal pigmented epithelial cells, that constitute the outer blood-retinal barrier, may be subjected to hyperosmolar stress resulting from different mechanisms. Herein, we review the possible origins and consequences of hyperosmolar stress on retinal pigmented epithelial cells during diabetic retinopathy, with a special focus on the intimate interplay between inflammation and hyperosmolar stress, as well as the current and forthcoming new pharmacotherapies for the treatment of such condition.

Adherence to diabetic eye examination guidelines in Australia: the National Eye Health Survey

OBJECTIVE

To determine adherence to NHMRC eye examination guidelines for Indigenous and non-Indigenous Australian people with diabetes.

DESIGN

Cross-sectional survey using multistage, random cluster sampling.

SETTING

Thirty randomly selected geographic sites in the five mainland Australian states and the Northern Territory, stratified by remoteness.

PARTICIPANTS

1738 Indigenous Australians aged 40-92 years and 3098 non-Indigenous Australians aged 50-98 years were recruited and examined between March 2015 and April 2016 according to a standardised protocol that included a questionnaire (administered by an interviewer) and a series of standard eye tests.

MAIN OUTCOME MEASURES

Adherence rates to NHMRC eye examination guidelines; factors influencing adherence.

RESULTS

Adherence to screening recommendations was significantly greater among non-Indigenous Australians (biennial screening; 77.5%) than Indigenous Australians (annual screening; 52.7%; P < 0.001). Greater adherence by non-Indigenous Australians was associated with longer duration of diabetes (adjusted odds ratio [aOR], 1.19 per 5 years; P = 0.018), while increasing age was associated with poorer adherence in non-Indigenous Australians (aOR, 0.70 per decade; P = 0.011). For Indigenous Australians, residing in inner regional areas (aOR, 1.66; P = 0.007) and being male (aOR, 1.46; P = 0.018) were significant factors positively associated with adherence.

CONCLUSIONS

More than three-quarters of non-Indigenous Australians with diabetes and more than half of Indigenous Australians with diabetes adhere to the NHMRC eye examination guidelines. The discrepancy between the adherence rates may point to gaps in the provision or uptake of screening services in Indigenous communities, or a lack of awareness of the guidelines. A carefully integrated diabetic retinopathy screening service is needed, particularly in remote areas, to improve adherence rates.

Retinal perfusion pressure and pulse pressure: clinical parameters predicting progression to sight-threatening diabetic retinopathy

Background and aims his paper investigates the roles of retinal perfusion pressure and pulse pressure in progression to sight-threatening diabetic retinopathy. Retinal perfusion pressure is dependent upon the systemic blood pressure and the intra-ocular pressure. We have examined the hypothesis that the early deleterious effect of hypertension on the retinal circulation which leads to perfusion pressure damage is due to a unique relationship between the intra-ocular pressure and the systemic blood pressure. Clinically this is manifest as hypertensive retinopathy and diabetic retinopathy.

Materials and methods From a prospective database, data on all new patients with background diabetic retinopathy referred during a three year period (n=104) were analysed for progression to sight-threatening diabetic retinopathy.

Results Retinal perfusion pressure and pulse pressure were found to be the strongest predictors of progression to sight-threatening diabetic retinopathy (Chi Square linear trend statistic, relative risk ratios).

Progression to maculopathy by quartilesFor retinal perfusion pressure, the relative risk ratios increased from 1.00 in the first quartile (39.7—50.1 mmHg), to x 5.8 in the second quartile (50.2—56.1 mmHg), to x 6.4 in the third quartile (56.2—60.0 mmHg), to x 9.1 in the fourth quartile (60.1—75.3 mmHg) (p=0.012). For pulse pressure the values were x 1.00, x 4.0, x 4.5, x 6.0 respectively (p=0.021). For systolic pressure the values were x 1.00, x 3.4, x 5.5, x 5.5 respectively (p=0.026). Diastolic pressure was not significant.

Progression to proliferative retinopathy by quartilesFor retinal perfusion pressure, the relative risk ratios increased from 1.00 in the first quartile to x 2.9 in the second quartile, x 4.2 in the third quartile to x 4.1 in the fourth quartile (p=0.002). For pulse pressure the values were x 1.00, x 1.7, x 3.8, x 5.5 respectively (p=0.002). For systolic pressure the values were x 1.00, x 0.5, x 2.9, x 3.8 respectively (p=0.008). Diastolic pressure was not significant.

Conclusion Retinal perfusion pressure and the pulse pressure are important predictors of progression to sight-threatening diabetic retinopathy.

Clinical Evaluation of Correlation Between Diabetic Retinopathy with Modifiable, Non-Modifiable and Other Independent Risk Factors in Tertiary Set-up in Central Rural India

INTRODUCTION

Diabetes mellitus and its related ocular complication like diabetic retinopathy (DR) are showing increased prevalence in India, but the magnitude of presence and progression of DR in central rural population and its relation to certain variables requires further exploration.

AIM

To study the demographic profile on diabetic retinopathy and the association between different risk factors of diabetic retinopathy with its onset and severity.

MATERIALS AND METHODS

A cross-sectional study was carried out on patients suffering from diabetes mellitus (n=100) admitted to AVBRH, Sawangi (Meghe) in a duration of 2 months from April to June 2014. Snellen's chart, slit lamp, and indirect ophthalmoscope were used for ocular examination of all patients. Comprehensive examination was used for risk factor assessment.

STATISTICAL ANALYSIS

All data was entered into the proforma. Chi-square test, Student's unpaired t-test and one way ANOVA using SPSS 17.0 and Graph Pad Prism 5.0. (p<0.05 was considered significant).

RESULTS

The study showed that among all the diabetics (mean age 56.4+11.2 years), 68% were males and 97% type 2 diabetics. This study showed statistically significant association between serum triglyceride (p=0.0003), duration since diagnosis of diabetes mellitus (p=0.0006), serum total cholesterol (p=0.0021), FBG (p=0.003), serum HDL (p=0.012) and hypertension (p=0.045) with presence of diabetic retinopathy. The study also revealed that serum triglycerides (p=0.001), serum total cholesterol (p=0.006), BMI (p=0.04) and duration of diabetes (p=0.04) are the only factors which showed significant association with the severity of diabetic retinopathy.

CONCLUSION

Effective screening strategies for early detection of both diabetes and diabetic retinopathy should be formulated especially for the rural population which is not aware about the various complications of diabetes and their final outcomes. Diabetics should follow proper guidelines to prevent or delay progression of DR.

Associations and interactions between lipid profiles, retinopathy and nephropathy in patients with type 1 diabetes: the FinnDiane Study

OBJECTIVES

The aim of this study was to investigate the associations between lipid profiles and retinopathy in the large nationwide FinnDiane Study and to examine interactions and correlations between retinopathy, nephropathy and lipid variables.

DESIGN AND SUBJECTS

A total of 1465 patients with type 1 diabetes, available lipid profiles, ophthalmic records and fundus photographs were included in the study. The Early Treatment of Diabetic Retinopathy Study scale was used to assess the severity of retinopathy. In an independent cohort of 1100 patients, laser treatment was used to define severe diabetic retinopathy.

RESULTS

HDL cholesterol was associated with proliferative retinopathy (PDR), and triglycerides were associated with mild nonproliferative retinopathy (NPDR) independently of nephropathy and other conventional risk factors (P < 0.01). Significant interactions were seen between albumin excretion rate (AER), retinopathy status and lipid parameters (including triglycerides, non-HDL cholesterol and apolipoprotein B; P < 0.001). Highly different correlations between AER and lipid variables were observed in patients without retinopathy or with mild NPDR compared with patients with moderate to severe NPDR or PDR. Similar interactions and correlations were observed in an independent cohort stratified by laser treatment. In patients without retinopathy or with mild NPDR, AER was low despite HDL cholesterol in the lowest or triglycerides, total cholesterol or LDL cholesterol in the highest quartiles.

CONCLUSIONS

Nephropathy had a strong effect on the associations between lipid variables and retinopathy, whilst dyslipidaemia was associated with nephropathy only in the presence of retinopathy. This finding suggests the existence of shared pathogenic mechanisms between retinopathy and nephropathy which could be targeted to prevent complications in patients with metabolic risk factors.

Modified Lipoproteins in Diabetic Retinopathy: A Local Action in the Retina

Clinical epidemiological studies have revealed relatively weak, yet statistically significant, associations between dyslipidemia/dyslipoproteinemia and diabetic retinopathy (DR). Recent large interventional studies, however, demonstrated an unexpectedly robust efficacy of fenofibrate on the development of DR, possibly independent of plasma lipids. To unify the apparent discrepancies, we hypothesize that plasma lipoproteins play an indirect but important role in DR, contingent on the integrity of the blood-retina-barrier (BRB). In retinas with an intact BRB, plasma lipoproteins may be largely irrelevant; however, important effects become operative after the BRB is impaired in diabetes, leading to lipoprotein extravasation and subsequent modification, hence toxicity to the neighbouring retinal cells. In this hypothesis, BRB leakage is the key, plasma lipoprotein concentrations mainly modulate its consequences, and fenofibrate has intra-retinal actions. This review summarizes our current knowledge of the direct effects and mechanisms of modified lipoproteins on retinal cells and their potential contribution to the pathogenesis of DR.

Variants of the adenosine A(2A) receptor gene are protective against proliferative diabetic retinopathy in patients with type 1 diabetes

AIMS

The adenosine A(2A) receptor (ADORA(2A)) may ameliorate deleterious physiologic effects associated with tissue injury in individuals with diabetes. We explored associations between variants of the ADORA(2A) gene and proliferative diabetic retinopathy (PDR) in a cohort of patients with type 1 diabetes (T1D).

METHODS

The participants were from the Pittsburgh Epidemiology of Diabetes Complications prospective study of childhood-onset T1D. Stereoscopic photographs of the retinal fundus taken at baseline, then biennially, for 10 years were used to define PDR according to the modified Airlie House system. Two tagging single nucleotide polymorphisms (tSNPs; rs2236624-C/T and rs4822489-G/T) in the ADORA(2A) gene were selected using the HapMap (haplotype map) reference database.

RESULTS

A significant association was observed between SNP rs2236624 and PDR in the recessive genetic model. Participants homozygous for the T allele displayed a decreased risk of developing prevalent PDR (odds ratio, OR = 0.36; p = 0.04) and incident PDR (hazard ratio = 0.156; p = 0.009), and for all cases of PDR combined (OR = 0.23; p = 0.001). The protective effect of T allele homozygosity remained after adjusting for covariates. Similarly, for SNP rs4822489, an association between PDR and T allele homozygosity was observed following covariate adjustment (OR = 0.55; 95% CI: 0.31-0.92; p = 0.04).

CONCLUSION

Genetic variants of ADORA(2A) offer statistically significant protection against PDR development in patients with T1D.

Augmentation pressure and subendocardial viability ratio are associated with microalbuminuria and with poor renal function in type 1 diabetes

In this report we explore the hypothesis that arterial stiffness indices, which predict cardiovascular disease, might also correlate with microalbuminuria (MA) in type 1 diabetes (T1D), and thus have potential for risk assessment. Three pulse wave analysis (PWA) indices, measured using the SphygmoCor device, were evaluated on 144 participants with childhood-onset T1D. These variables, augmentation index (AIx), augmentation pressure (AP) and subendocardial viability ratio (SEVR, an estimate of myocardial perfusion) (an estimate of myocardial perfusion), were each analysed cross-sectionally in relation to both prevalent MA (defined as albuminuria excretion rate (AER) = 20-199 microg/min) and renal function (assessed by both eGFR and serum cystatin C). AP and SEVR were each univariately associated with AER, estimated glomerular filtration rate (eGFR) and cystatin C. Lower SEVR was also independently related to the presence of MA and degree of albuminuria within normo- and microalbuminuric participants. SEVR, not AP, was independently and negatively associated with both measures of renal function. SEVR is a better predictor of AER than brachial blood pressure measures in those without clinical proteinuria, indicating a potential use for PWA in the early detection of individuals at risk for cardiovascular and renal complications of T1D.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy XXIII: the twenty-five-year incidence of macular edema in persons with type 1 diabetes

OBJECTIVE

To examine the 25-year cumulative incidence of macular edema (ME) and its relation to various risk factors.

DESIGN

Population-based study.

PARTICIPANTS

A total of 955 insulin-taking persons living in an 11-county area in southern Wisconsin with type 1 diabetes diagnosed before age 30 years who participated in baseline examinations (1980-1982) and at least 1 of 4 follow-up (4-, 10-, 14-, and 25-year) examinations (n=891) or died before the first follow-up examination (n=64).

METHODS

Stereoscopic color fundus photographs were graded using the modified Airlie House classification and the Early Treatment Diabetic Retinopathy Study retinopathy severity scheme. Competing risk of death was included in statistical models.

MAIN OUTCOME MEASURES

Incidence of ME and clinically significant ME (CSME).

RESULTS

The 25-year cumulative incidence was 29% for ME and 17% for CSME. Annualized incidences of ME were 2.3%, 2.1%, 2.3%, and 0.9% in the first, second, third, and fourth follow-up periods of the study, respectively. In univariate analyses, the incidence of ME was associated with male sex, more severe diabetic retinopathy, higher glycosylated hemoglobin, proteinuria, higher systolic and diastolic blood pressure, and more pack-years of smoking. Multivariate analyses showed that the incidence of ME was related to higher baseline glycosylated hemoglobin (hazard ratio [HR] per 1% 1.17; 95% confidence interval [CI], 1.10-1.25; P<0.001) and higher systolic blood pressure (HR per 10 mmHg 1.15; 95% CI, 1.04-1.26; P=0.004) and marginally to proteinuria (HR 1.43; 95% CI, 0.99-2.08; P=0.06).

CONCLUSIONS

These data show that relatively high 25-year cumulative rates of incidence of ME were related to glycemia and blood pressure. The lower risk of incident ME in the last period of the study may reflect recent improvement in care.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy: XXII the twenty-five-year progression of retinopathy in persons with type 1 diabetes

OBJECTIVE

To examine the 25-year cumulative progression and regression of diabetic retinopathy (DR) and its relation to various risk factors.

DESIGN

Population-based study.

PARTICIPANTS

A total of 955 insulin-taking persons living in an 11-county area in southern Wisconsin with type 1 diabetes diagnosed before age 30 years who participated in a baseline examination (1980-1982) and at least 1 of 4 follow-up (4-, 10-, 14-, and 25-year) examinations or died before the first follow-up examination (n = 64).

METHODS

Stereoscopic color fundus photographs were graded using the modified Airlie House classification and the Early Treatment Diabetic Retinopathy Study retinopathy severity scheme.

MAIN OUTCOME MEASURES

Progression and regression of DR status.

RESULTS

The 25-year cumulative rate of progression of DR was 83%, progression to proliferative DR (PDR) was 42%, and improvement of DR was 18%. Progression of DR was more likely with less severe DR, male sex, higher glycosylated hemoglobin, an increase in glycosylated hemoglobin level, and an increase in diastolic blood pressure level from the baseline to the 4-year follow-up. Increased risk of incidence of PDR was associated with higher glycosylated hemoglobin, higher systolic blood pressure, proteinuria greater body mass index at baseline, and an increase in the glycosylated hemoglobin between the baseline and 4-year follow-up examinations. Lower glycosylated hemoglobin and male sex, as well as decreases in glycosylated hemoglobin and diastolic blood pressure during the first 4 years of follow-up, were associated with improvement in DR. Persons diagnosed most recently with a similar duration of diabetes had a lower prevalence of PDR independently of glycosylated hemoglobin level, blood pressure level, and presence of proteinuria.

CONCLUSIONS

These data show relatively high 25-year cumulative rates of progression of DR and incidence of PDR. The lower risk of prevalent PDR in more recently diagnosed persons possibly reflects improvement in care over the period of the study.

Proteome Profiling of Vitreoretinal Diseases by Cluster Analysis

Vitreous samples collected in retinopathic surgeries have diverse properties, making proteomics analysis difficult. We report a cluster analysis to evade this difficulty. Vitreous and subretinal fluid samples were collected from 60 patients during surgical operation of non-proliferative diabetic retinopathy, proliferative diabetic retinopathy, proliferative vitreoretinopathy, and rhegmatogenous retinal detachment. For controls we collected vitreous fluid from patients of idiopathic macular hole, epiretinal, and from a healthy postmortem donor. Proteins from these samples were subjected to quantitative proteomics using two-dimensional gel electrophoresis. We selected 105 proteins robustly expressed among ca 400 protein spots and subjected them to permutation test. By using permutation test analysis we observed unique variations in the expression of some of these proteins in vitreoretinal diseases when compared to the control and to each other: 1) the levels of inflammation-associate proteins such as AAT, APOA4, ALB, and TF were significantly higher in all four types of vitreoretinal diseases, and 2) each vitreoretinal disease elevates a unique set of proteins which can be interpreted based on the pathology of retinopathy. Our protocol will be effective for the study of protein expression in other types of clinical samples of diverse property.

Rationale, design, and methods of the Action to Control Cardiovascular Risk in Diabetes Eye Study (ACCORD-EYE)

Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus. The Action to Control Cardiovascular Risk in Diabetes Eye Study (ACCORD-EYE), a prospective study of a subset of patients in the randomized controlled clinical ACCORD trial, is being conducted at enrollment and after 4 years of follow-up to assess the progression of DR with standardized comprehensive eye exams and fundus photography of 7 standard stereoscopic fields. This study aims to assess the effects of the ACCORD medical treatment strategies of tight control of glycemia and blood pressure and management of dyslipidemia on the course of DR in patients with type 2 diabetes. Photographs will be evaluated at a centralized location using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) classification. The primary outcome of ACCORD-EYE, which will measure the development and progression of DR, is a composite of (1) progression of DR (> or = 3 steps on the ETDRS scale), (2) photocoagulation for DR, or (3) vitrectomy for DR. Specifically, the following questions will be addressed: (1) Does a therapeutic strategy targeting a glycosylated hemoglobin (HbA(1c)) level <6.0% reduce development and progression of DR more than one targeting an HbA(1c) level of 7.0%-7.9% (target median level, 7.5%)? (2) In the context of good glycemic control, does a strategy using a fibrate to increase high-density lipoprotein cholesterol and lower triglyceride levels and a statin to maintain the level of low-density lipoprotein (LDL) cholesterol at <2.59 mmol/L (100 mg/dL) reduce development and progression of DR compared with one using placebo and a statin to treat LDL cholesterol? (3) In the context of good glycemic control, does a strategy targeting a systolic blood pressure level <120 mm Hg reduce development and progression of DR compared with one targeting a level <140 mm Hg? Secondary outcome variables include various levels of loss of visual acuity at 4 years versus baseline, cataract extraction, and the development or progression of diabetic macular edema. Methods to measure DR progression have been incorporated into ACCORD, and complete baseline data have been collected on 3,537 participants. These data will provide valuable information regarding the effects of medical treatment on the prevention and progression of DR.

The eye in hypertension

Hypertension has a range of effects on the eye. Hypertensive retinopathy refers to retinal microvascular signs that develop in response to raised blood pressure. Signs of hypertensive retinopathy are frequently seen in adults 40 years and older, and are predictive of incident stroke, congestive heart failure, and cardiovascular mortality--independently of traditional risk factors. Hypertension is also a major risk factor for the development of other retinal vascular diseases, such as retinal vein and artery occlusion, and ischaemic optic neuropathy. High blood pressure increases the risk of both development of diabetic retinopathy and its progression. Adequate control of blood pressure has been proven in randomised clinical trials to reduce vision loss associated with diabetic retinopathy. Finally, hypertension has been implicated in the pathogenesis of glaucoma and age-related macular degeneration. Recognition of the ocular effects of blood pressure could allow physicians to better manage patients with hypertension, and to monitor its end-organ effects.

Lower-than-expected prevalence and severity of retinopathy in an incident cohort followed during the first 4-14 years of type 1 diabetes: the Wisconsin Diabetes Registry Study

The authors examined the development of diabetic retinopathy in a population-based cohort of persons with incident type 1 diabetes to investigate the possibility of lowered retinopathy prevalence and severity compared with previous US studies. A total of 474 diabetic persons from Wisconsin were followed from diagnosis through 4-14 years' duration during 1990-2002. Retinopathy was determined by fundus photography at 4, 7, 9, and 14 years' duration. Risk of developing retinopathy was modeled on demographic and diabetes-care characteristics by means of a generalized linear model using the complementary log-log link for interval-censored data. Prevalence of retinopathy increased with duration of diabetes, from 6% at 4 years to 73% at 14 years, and was highest among adults (> or =20 years of age). Risk of developing retinopathy increased with increasing duration, worse glycemic control, and age up to 20 years. Indicators of diabetes care were related to retinopathy through their effect on glycemic control. Improvements in diabetes care leading to better glycemic control may have contributed to the much lower prevalence and less severe retinopathy observed than expected on the basis of a previous report from the same region of Wisconsin. The observed decreased prevalence has important implications for persons with type 1 diabetes, since retinopathy is a serious microvascular complication.

The North Jutland County Diabetic Retinopathy Study: population characteristics

BACKGROUND

Several population-based studies have reported blood glucose levels and blood pressure to be risk factors for the development of diabetic retinopathy. These studies were initiated more than two decades ago and may therefore reflect the treatment and population composition of a previous era, suggesting new studies of the present population with diabetes.

AIM AND METHODS

This cross-section study included 656 people with type 1 diabetes and 328 with type 2 diabetes. Crude prevalence rates of proliferative diabetic retinopathy, clinically significant macular oedema and several specific retinal lesions were assessed, together with their association to a simplified and internationally approved retinal grading.

RESULTS

The point prevalence of proliferative retinopathy was found to be 0.8% and 0.3% for type 1 and type 2 diabetes. Equivalent prevalence rates of clinically significant macular oedema were 7.9% and 12.8%, respectively. The most frequently occurring retinal manifestations increased in number until retinopathy level 3, and then decreased.

CONCLUSION

The point prevalence of proliferative retinopathy is lower than that found in previous studies, whereas it is increased for clinically significant macular oedema. These data suggest different risk factors for these clinical entities.

Proteinuria in Diabetic Patients – Is It Always Diabetic Nephropathy?

BACKGROUND

Diabetic nephropathy (dNP) is a consequence of type 1 and type 2 diabetes, typically occurring between 5 and 15 years after diabetes has been diagnosed. The coincidence of dNP and diabetic retinopathy (dRP) is well known. In this study we correlated the histological findings of the kidney biopsy with the clinically expected diagnosis of dNP.

PATIENTS AND METHODS

Over a 4-year period with a total of 326 kidney biopsies, 85 biopsies were performed on patients with diabetes. In all of these patients we had information about duration of diabetes and ophthalmological status. Additionally, data about proteinuria, urine sediment and autoantibodies were available. The nephrologist had to give the suspected diagnosis before the biopsy was performed, using the clinical data available.

RESULTS

In 57 patients (67%) dNP was predicted clinically before biopsy. In 28 patients we expected a different kind of kidney disease. Only 43 patients had dNP histologically. In 16 out of 19 patients with dRP we also found dNP. 26 patients with dNP did not have dRP. So dRP was very specific but not sensitive to predict dNP. On the other hand, all patients without dRP but acanthocytes in urine sediment had non-diabetic kidney disease (NDKD). In the case of patients with neither dRP nor acanthocytes, it was very difficult to distinguish between dNP and NDKD. Acanthocytes and antineutrophil cytoplasmatic antibodies with positive antibodies for proteinase 3 or myeloperoxidase were found only in NDKD, but ANAs were detected in a wide titer range in dNP and NDKD. The known duration of the diabetes ranged from 1 to 40 years. There were no additional parameters to differentiate this group.

CONCLUSIONS

Diabetic patients with dRP and proteinuria frequently have dNP. In patients without typical retinal findings dNP is less likely, thus a kidney biopsy is necessary to confirm the diagnosis. Additional knowledge about urine sediment and autoantibodies is helpful, but is not sufficient to differentiate NDKD from dNP in the majority of patients.

The prevention of diabetic microvascular complications of diabetes: is there a role for lipid lowering?

The role of hyperglycemia in the development of microvascular complications of diabetes, such as nephropathy, retinopathy and neuropathy, has been well documented. Evidence is accumulating to support the concept that dyslipidemia can also contribute to the development of these complications. Lipid-lowering agents, such as statins, have been shown to prevent cardiovascular events in patients with diabetes. However, in addition to preventing macrovascular diseases, statins may also be able to retard the progression of microvascular complications of diabetes. Indeed, in addition to reducing lipid levels, these agents can improve endothelial function and reduce oxidative stress, which can improve microvascular function. These findings would provide further support for the use of lipid-lowering agents in patients with diabetes.

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.

The role of lipids in the development of diabetic microvascular complications: implications for therapy

Dyslipidemia is a major factor responsible for coronary heart disease and its reduction decreases coronary risk in patients with diabetes mellitus. However, the association of dyslipidemia with microvascular complications and the effect of intervention with lipid-lowering therapy in diabetes have been less investigated. We present the systematic review of association and intervention studies pertaining to dyslipidemia and microvascular disease in diabetes and also review possible mechanisms. Dyslipidemia may cause or exacerbate diabetic retinopathy and nephropathy by alterations in the coagulation-fibrinolytic system, changes in membrane permeability, damage to endothelial cells and increased atherosclerosis. Hyperlipidemia is associated with faster decline in glomerular filtration rate and progression of albuminuria and nephropathy. Recent evidence also suggests a role of lipoprotein(a) in progression of retinopathy and nephropathy in patients with diabetes mellitus. Lipid-lowering therapy, using single agents or a combination of drugs may significantly benefit diabetic retinopathy and diabetic nephropathy. In particular, hydroxymethyl glutaryl coenzyme A reductase inhibitors may be effective in preventing or retarding the progression of microvascular complications because of their powerful lipid-lowering effects and other additional mechanisms. However, most of the data are based on short-term studies, and need to be ascertained in long-term studies. Until more specific guidelines are available, aggressive management of diabetic dyslipidemia, according to currently accepted guidelines, should be continued for the prevention of macrovascular disease which would also benefit microvascular complications.

Epidemiology of diabetic retinopathy

Diabetic retinopathy is associated with a number of systemic risk factors, namely hyperglycaemia, elevated blood pressure and dyslipidaemia. Patients with diabetes should be vigorously treated for these modifiable risk factors to prevent the development and progression of diabetic retinopathy.

The association of atherosclerosis, vascular risk factors, and retinopathy in adults with diabetes : the atherosclerosis risk in communities study

PURPOSE

The aim of this report is to describe the prevalence of retinopathy and its associations with atherosclerosis and vascular risk factors in people with diabetes.

DESIGN

Cross-sectional study.

PARTICIPANTS

Persons with diabetes, having gradable fundus photographs, from a biracial population-based cohort of adults (ages 51-72 years), and living in four United States communities (Forsyth County, North Carolina; the city of Jackson, Mississippi; suburbs of Minneapolis, Minnesota; and Washington County, Maryland) were studied from 1993 to 1995.

METHODS

Lesions typical of diabetic retinopathy were detected by grading a 45 degrees color fundus photograph of one eye of each participant, using a modification of the Airlie House classification system.

MAIN OUTCOME MEASURE

Severity of diabetic retinopathy (none, minimal nonproliferative, moderate nonproliferative, severe nonproliferative, and proliferative) and macular edema.

RESULTS

Retinopathy was detected in 328/1600 (20.5%) of those with diabetes; 114/1724 (6.6%) had hard exudate, 28/1600 (1.8%) had proliferative diabetic retinopathy, and 27/1662 (1.6%) had macular edema. The prevalence of diabetic retinopathy was higher in blacks (27.7%) compared with whites (16.7%). Controlling for duration of diabetes, serum glucose, systolic blood pressure, and type of diabetes medications taken, severity of retinopathy was associated with carotid artery intima-media wall thickness (odds ratio [OR]/0.1-mm thickness 1.09; 95% confidence interval [CI], 1.01, 1.17; P = 0.01), serum albumin (OR/0.1 g/dl 0.94; 95% CI, 0.88, 0.99; P = 0.02), but not race (OR blacks versus whites,1.24; 95% CI, 0.88, 1.75; P = 0.21). Severity of diabetic retinopathy was not associated with coronary artery disease or stroke history or any of the plasma lipids studied. Controlling for age, gender, duration of diabetes, serum glucose, and type of diabetes medications taken, the presence of retinal hard exudates was associated with plasma low-density lipoprotein cholesterol (OR/10 mg/dl 1.18; 95% CI, 1.09, 1.29; P < 0.001), and plasma Lp(a) (OR/10 mg/dl 1.02; 95% CI, 1.00, 1.05; P = 0.04) but not race or blood pressure.

CONCLUSIONS

These data suggest that plasma lipids are associated with the presence of hard exudate and that carotid artery intima-media wall thickness is associated with retinopathy, but other manifestations of atherosclerosis and most of its risk factors are not associated with severity of diabetic retinopathy.

Complications of pediatric and adolescent type 1 diabetes mellitus

Type 1 diabetes mellitus is potentially associated with serious microvascular and macrovascular complications, although these are usually subclinical during the pediatric and adolescent years. There is no "grace" period for the beginnings of such complications. Duration of diabetes, glycemic control, age, and pubertal stage are critical factors contributing toward development of such problems. Other risk factors include family history (genetic predisposition), hyperlipidemia, hypertension, and smoking. The Diabetes Control and Complications Trial (DCCT) proved the importance of glycemic control and emphasized the ability of improved glucose control to prevent or decrease retinopathy, nephropathy, and neuropathy using a multidisciplinary same-philosophy-of-care approach plus targeted glucose and hemoglobin A(1c) values. Other natural history and intervention studies support the findings of the DCCT. Although our current tools are not perfect, they allow us to decrease microangiopathic complications very significantly if we educate our patients and their family members. Metabolic control counts.

Diabetic retinopathy after combined kidney-pancreas transplantation

Diabetic retinopathy (DR) is amenable to good diabetic control; however, only successful pancreas transplantation can achieve sustained normoglycaemia. The aim of this long-term study was to examine the course of DR in insulin-dependent diabetic recipients of a simultaneous kidney and pancreas transplant (SPK). Successful SPK recipients (n = 46) and failed pancreas transplant with a functioning kidney transplant (n = 8) were assessed by baseline and regular post-transplant ophthalmic examinations (n = 432) for up to 10 yr after SPK. At the time of SPK (n = 108 eyes), the mean duration of diabetes was 25 +/- 7 yr, ten eyes were blind, and 79% of eyes had advanced DR that had panretinal laser (panretinal photocoagulation, PRP. Successful SPK recipients had normal glucose control with a mean HBA1C of 5.2 +/- 0.6%. DR remained stable in 75% of both the study and control groups, with no difference between groups. The DR mostly evolved towards inactive proliferative DR. After SPK, 14% of non-blind eyes showed improvement of DR, 76% remained stable and 10% progressed. Early vitreous haemorrhage occurred in 6.1% of eyes, and was related to established DR. Cataract of all types increased after transplantation (p < 0.01), which reduced visual acuity (VA) in affected eyes. The mean overall VA remained unchanged for the study duration. In summary, uremic patients from diabetic nephropathy had a high prevalence of severe proliferative DR and blindness at the time of presentation for SPK. This was subsequently stabilised to inactive proliferative DR by appropriate laser therapy followed by metabolic control achieved by SPK.

Determinants of retinopathy progression in type 1 diabetes mellitus

PURPOSE

To determine the risk factors for retinopathy progression in type 1 (insulin-dependent) diabetes mellitus in a prospective cohort study.

SUBJECTS AND METHODS

Subjects were 485 participants in the Sorbinil Retinopathy Trial, a randomized trial of aldose reductase inhibition among patients aged 18 to 56 years with type 1 diabetes mellitus (duration of 1 to 15 years) and no or only mild retinopathy. Retinopathy progression, assessed by seven-field stereoscopic fundus photography, was defined as worsening by two or more levels on a standardized grading scale at the end of follow-up (median, 41 months).

RESULTS

The relative risks for retinopathy progression according to successively greater quintiles of total glycosylated hemoglobin level at baseline, after adjusting for age, diabetes duration, sorbinil assignment, and other variables, were 1.0, 2.0, 1.6, 3.7, and 4.4 (P trend <0.0001). Risk increased with greater baseline diastolic blood pressure: 1.0 for <70 mm Hg, 1.2 for 70 to 79 mm Hg, and 1.8 for > or =80 mm Hg (P for trend = 0.04). Diastolic blood pressure was a significant risk factor for progression in participants with mild baseline retinopathy (P for trend <0.02) but not in those without retinopathy at entry. Systolic blood pressure, by comparison, was not associated with progression. Baseline total cholesterol level was a marginally significant predictor of retinopathy progression when examined as a categorical variable (relative risks for increasing quartiles; 1.0, 1.6, 1.8, 1.9; P for trend = 0.03) but not when it was examined as a continuous variable or when hypercholesterolemic patients were compared with those with normal levels. Furthermore, when cholesterol levels were updated in subsequent visits, it was not a significant predictor of progression, and low density lipoprotein (LDL) cholesterol levels did not predict progression no matter how analyzed. Smoking was not associated with progression of retinopathy.

CONCLUSIONS

Levels of hyperglycemia and diastolic blood pressure predicted progression of retinopathy in type 1 diabetes mellitus. We found only a suggestion of an association between total cholesterol level (but not of LDL cholesterol level) and progression of retinopathy; resolution of this issue will require additional studies with larger sample sizes and longer follow-up.

Association of plasma fibrinogen level and blood pressure with diabetic retinopathy, and renal complications associated with proliferative diabetic retinopathy, in Type 2 diabetes mellitus

AIM

To clarify the association of several clinical parameters, including plasma fibrinogen level, with diabetic retinopathy in patients with Type 2 diabetes mellitus (DM).

METHODS

A total of 294 Japanese patients with Type 2DM were studied; 53 patients with no diabetic retinopathy (NDR), 90 with background diabetic retinopathy (BDR), and 151 with proliferative diabetic retinopathy (PDR). Multiple logistic regression analysis was performed to assess variables independently associated with diabetic retinopathy in two settings: presence of retinopathy of any severity and presence of advanced retinopathy.

RESULTS

The following parameters were identified as independent factors associated with the presence of diabetic retinopathy (NDR vs. BDR + PDR): type of therapy (P<0.0005), log-transformed plasma fibrinogen level (P < 0.05), mean blood pressure (P < 0.05), and duration of diabetes (P < 0.05). The independent variables associated with advanced retinopathy were type of therapy (P<0.00005), age (P<0.0005) and nephropathy (P<0.05). Body mass index, smoking and hypertensive status, HbA1c and total cholesterol levels were not independently associated.

CONCLUSIONS

These data suggest that in patients with Type 2 DM, an increased blood viscosity due to high fibrinogen level as well as an elevated intravessel pressure play a role in the development of diabetic retinopathy, and that the progression to PDR is influenced or accompanied by the deterioration of renal status.

Ocular neovascularization: an epidemiologic review

Neovascularization occurs in many eye diseases, and its epidemiologic impact is significant. However, data on the prevalence and incidence of ocular neovascularization have never been compiled to demonstrate its pervasiveness. This overview of ocular angiogenesis provides a review of the epidemiologic literature for neovascularization in various parts of the eye, including the cornea, iris, retina, and choroid. Relevant disease states are reviewed, as are their risk factors, so that their pathogenesis can be better understood. Data on the prevalence and incidence of the major diseases involving angiogenesis are synthesized to provide statistical evidence of the span and magnitude of ocular neovascularization. These prevalence and incidence data on ocular neovascularization are extrapolated to USA population data where possible, and "worst-case" estimates are calculated as well. Information was gathered with a search of the MEDLINE database, published monographs and volumes, and consultation with a number of primary authors. This study attempts to unify much of past and present epidemiologic research, and the information is presented in sections divided according to the anatomy of the eye.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy: XVII. The 14-year incidence and progression of diabetic retinopathy and associated risk factors in type 1 diabetes

OBJECTIVE

To examine the 14-year incidence and progression of diabetic retinopathy and macular edema and its relation to various risk factors.

DESIGN

Population-based incidence study.

SETTING

The study was conducted in an 11-county area in southern Wisconsin.

PARTICIPANTS

Six hundred thirty-four insulin-taking persons with diabetes diagnosed before age 30 years participated in baseline, 4-year, 10-year, and 14-year follow-up examinations.

MAIN OUTCOME MEASURES

The 14-year progression of retinopathy, progression to proliferative retinopathy, and incidence of macular edema were detected by masked grading of stereoscopic color fundus photographs using the modified Airlie House classification and the Early Treatment Diabetic Retinopathy Study retinopathy severity scheme.

RESULTS

The 14-year rate of progression of retinopathy was 86%, regression of retinopathy was 17%, progression to proliferative retinopathy was 37%, and incidence of macular edema was 26%. Progression of retinopathy was more likely with less severe retinopathy, being male, having higher glycosylated hemoglobin or diastolic blood pressure at baseline, an increase in the glycosylated hemoglobin level, and an increase in diastolic blood pressure level from the baseline to the 4-year follow-up. Increased risk of proliferative retinopathy or incidence of macular edema was associated with more severe baseline retinopathy, higher glycosylated hemoglobin at baseline, and an increase in the glycosylated hemoglobin between the baseline and 4-year follow-up examination. The increased risk of proliferative retinopathy was associated with the presence of hypertension at baseline, whereas the increased risk of a participant having macular edema develop was associated with the presence of gross proteinuria at baseline. Lower glycosylated hemoglobin at baseline was associated with improvement in retinopathy.

CONCLUSIONS

These data suggest relatively high 14-year rates of progression of retinopathy and incidence of macular edema. These data also suggest that a reduction of hyperglycemia and hypertension may result in a beneficial decrease in the progression to proliferative retinopathy.

Lipids and lipoproteins in diabetic adolescents and young adults with retinopathy

PURPOSE

To compare serum concentrations of lipoproteins and apolipoproteins in insulin-dependent diabetic patients with and without retinopathy.

METHODS

A cross-sectional study was performed on 42 diabetic adolescents and young adults with different degrees of retinopathy. The mean +/- SD age of the patient was 21.1 years (range 12.8-27.9 years); their mean duration of diabetes was 12.3 years (range 7.1-19.9 years). Their glycosylated haemoglobin (HbA1c) and fructosamine were respectively 10.2% (8.2-15.4%) and 280.8 mumol/l (202.1-458.5 mumol/l). Forty-two diabetics without retinopathy similar to the study population as regards age, sex, duration of disease, HbA1c and microalbuminuria values, and 42 healthy subjects, served as controls.

RESULTS

Serum lipid and lipoprotein concentrations were not different from those of healthy controls in patients either with or without retinopathy. The diabetic patients were subdivided in two groups according to the degree of their retinopathy: background and preproliferative/proliferative retinopathy. Patients with preproliferative/proliferative retinopathy were found to have significantly higher lipoprotein (a) values than the other group (background, 73.3 IU/l; preproliferative/proliferative, 205.9 IU/l; p < 0.001).

CONCLUSION

The increase in lipoprotein (a) levels might play a role in the development of severe retinopathy.

The incidence of nephropathy in type 1 diabetic patients with proliferative retinopathy: a 10-year follow-up study

Patients with type 1 diabetes mellitus and with proliferative retinopathy often have a concomitant diabetic nephropathy. However, in cross-sectional studies it has been shown that 35% of patients with proliferative retinopathy do not show signs of diabetic nephropathy. The aim of the present study was to examine the incidence of diabetic nephropathy in type 1 diabetic patients with proliferative retinopathy but without signs of nephropathy. To that end, out of 102 consecutive patients with proliferative retinopathy attending the University Hospital, Lund, in 1986, 24 patients did not show any clinical signs of nephropathy, and were followed for 10 years regarding the development of nephropathy. Their age was 36.7 +/- 9.8 years, age at onset 11.8 +/- 7.5 years, diabetes duration 25.7 +/- 6.9 years and duration of proliferative retinopathy 4.6 +/- 3.8 years (mean +/- S.D.). At entry, no patient had albuminuria (< 30 mg/l), and albumin creatinine clearance ratio was < 0.01 x 10(-3). During the 10-year follow-up period, two of the patients showed isolated higher peaks of elevated urinary albumin, but none of the 24 patients developed persistent microalbuminuria (> or = 30 mg/l). Two patients died before follow-up, but none of these had developed microalbuminuria at the time for death. Based on mean annual measurements, there were no increases in HbA1c, systolic and diastolic blood pressure, and serum creatinine levels. At entry, seven of the patients were treated with antihypertensive drugs and another three patients received such treatment during the study period. In conclusion, in a subgroup of patients with proliferative retinopathy, i.e. without clinical signs of diabetic nephropathy, no patient developed persistent microalbuminuria during a 10-year follow-up period. These results indicate further evidence for at least partly different pathogenic mechanisms behind diabetic retinopathy and nephropathy.

Photographic detection of retinopathy in insulin-treated diabetes. A population study in the city of Tartu, Estonia

PURPOSE

To perform a cross-sectional baseline investigation of diabetic retinopathy prevalence and metabolic control.

METHODS

Using a register of insulin-dependent diabetes mellitus in Tartu (pop. 104,791), 175 patients were invited to fundus photography; 149 (89%) participated, 99 of them diagnosed with diabetes before the age of thirty. Four Kodachrome 64 photographs per eye were taken with a Canon CR4 - 45NM camera through tropicamide-dilated pupils; slides were projected and systematically graded. Capillary blood samples (n = 132) for HbA1c determination were mailed on filter paper. Following cysteine buffer elution, Mono S ion exchange chromatography was performed (reference range 3.7 to 5.3%).

RESULTS

Any diabetic retinopathy was found in 114 patients (76.5%; 95% confidence interval, CI, 70 to 83%); mild to moderate non-proliferative retinopathy in 59 (40%; 95% CI 32 to 48%); severe non-proliferative retinopathy in 29 (19.5%; 95% CI 13 to 26%); proliferative retinopathy in 26 (17%; 95% CI 11 to 24%); 47 patients (32%) needed laser photocoagulation. Vitreous haemorrhage was observed in 9 (6%) of subjects. In patients diagnosed with diabetes before the age of 30 years, prevalence of any retinopathy was 82% (95% CI 73 to 89%) and of proliferative retinopathy 23% (95% CI 15 to 33%). Median HbA1c was 9.7% for women and 8.6% for men (95% CI for difference 0.7 to 2.1%).

CONCLUSION

Retinopathy prevalences (76-82%) are the highest reported from population-based studies. Glycaemia levels were very high and should be gradually lowered. Methods capable of validation can be successfully introduced for population-based assessment of hyperglycaemia and retinopathy prevalences.

Do tissue plasminogen activator-plasminogen activator inhibitor-1 complexes relate to the complications of insulin-dependent diabetes mellitus? Pittsburgh Epidemiology of Diabetes Complications Study

The purpose of this study was to examine the potential relationship of tissue plasminogen activator-plasminogen activator inhibitor-1 (tPA-PAI-1) complexes and diabetic complications in individuals with insulin-dependent diabetes mellitus (IDDM). To address this issue, data from the third follow-up visit of participants in the Epidemiology of Diabetes Complications (EDC) study were examined. There were 454 participants, aged 32 +/- 8 years, with duration of IDDM of 23 +/- 8 years. Higher levels of tPA-PAI-1 complexes were seen for both men and women with IDDM complications. Specifically, statistically significant differences were seen in men with neuropathy (1.81 +/- 0.9 versus 1.42 +/- 0.8 ng/mL, p < 0.01), microalbuminuria (1.77 +/- 1.1 versus 1.35 +/- 0.6 ng/mL, p < 0.01), retinopathy (1.67 +/- 0.9 versus 1.43 +/- 0.8 ng/mL, p < 0.05), and lower extremity arterial disease (1.93 +/- 0.7 versus 1.50 +/- 0.9 ng/mL, p < 0.05) versus men without the particular complication. In women, higher complex levels were shown for those with retinopathy (1.51 +/- 0.8 versus 1.29 +/- 1.1 ng/mL, p < 0.01). Potential mechanisms for the relationship of higher complex levels and diabetic complications include an altered fibrinolytic response and/or insulin resistance. Because the results are cross sectional, it cannot be established whether the higher concentration of complexes is a result of the presence of complications or are antecedent. Prospective follow-up will be required to determine if tPA-PAI-1 complexes are predictive of the development of IDDM complications.

Retinopathy and vision loss in insulin-dependent diabetes in Europe. The EURODIAB IDDM Complications Study

PURPOSE

To assess the frequency of retinopathy and vision loss in patients with insulin-dependent diabetes mellitus and their relations to potentially modifiable risk factors.

METHODS

The authors conducted a multicenter cross-sectional study of diabetic complications and their risk factors using standardized methods of assessment. The sample was comprised of 3250 insulin-dependent diabetic patients (1668 men, 1582 women) aged 15 to 60 years with mean (standard deviation) duration of diabetes of 14.7 (9.3) years from 31 European diabetes centers; 2991 of the patients were eligible for retinal photography. Visual acuity was measured using the Snellen chart. Retinopathy was evaluated by retinal photographs (two fields per eye) graded at a central facility. Glycated hemoglobin (HbA1c), cholesterol, triglyceride, fibrinogen, von Willebrand factor, and urinary albumin excretion rate were assessed at a single location.

RESULTS

Corrected visual acuity was greater than or equal to 1.0 in both eyes in 69.7% of patients and less than or equal to 0.1 in the best eye in 2.3%. Factors significantly related to vision loss were age, duration of diabetes, glycated hemoglobin (HbA1c), and level of retinopathy. Mild nonproliferative retinopathy was found in 25.8% of the patients, moderate-severe nonproliferative retinopathy in 9.8% of the patients, and proliferative retinopathy in 10.6% of the patients. After adjustment for age, duration of diabetes, HbA1c, and albumin excretion rate, significant risk factors for moderate-severe nonproliferative retinopathy were blood pressure and triglyceride, and risk factors for proliferative retinopathy were triglyceride and fibrinogen.

CONCLUSION

Vision loss is a common complication of patients with insulin-dependent diabetes, with diabetic retinopathy an important cause. Apart from poor glycemic control, several other potentially modifiable risk factors for retinopathy may be important, including elevated blood pressure, plasma triglyceride, and fibrinogen. In view of the possible barriers to the full implementation of strict glycemic control in this type of diabetes, additional strategies for the prevention and slowing of progression of retinopathy should be investigated, such as blood pressure and lipid lowering therapies.

Retinopathy in Maltese type 2 diabetic patients

Since diabetes is a major health problem in Malta a study was conducted to gain a better insight into one of its most common complications, that of retinopathy. A random sample of 200 cases of adult onset diabetes with retinopathy who attended the main hospital's diabetes clinic was assessed by an experienced ophthalmologist. Non-proliferative retinopathy was subdivided into three degrees of severity according to the number of microaneurysms, haemorrhages, exudates, and intraretinal microvascular abnormalities present while proliferative retinopathy included also advanced eye disease. Data on medical and family histories was gathered from personal interrogation and counterchecked from hospital files. A medical examination searched for other concomitant disease. The 124 females and 73 males were similarly aged with a mean of 59.5 +/- 11.5 years. The mean age at onset of diabetes was 44.4 +/- 7.9 years: no significant differences were seen between the grades of retinopathy or the sexes. Onset of eye disease was first detected at a mean age of 56.9 +/- 7.0 years. The great majority (82%) of retinopathy cases occurred after 10 years of diabetes. Males appeared to develop eye disease (especially non-proliferative) at a younger age (53.4 +/- 7.6 vs 58.9 +/- 6.6 years, p < 0.01) and after a shorter duration of diabetes (10.1 +/- 6.6 vs 14.0 +/- 7.8 years, p < 0.001) than females. Severity of retinopathy was strongly associated (p < 0.001), in females rather more than in males, with poor glycaemic control, use of insulin, presence of proteinuria and decreasing vision; and less markedly (p < 0.01) with duration of diabetes of more than 10 years, neuropathy and glaucoma.(ABSTRACT TRUNCATED AT 250 WORDS)