The prevalence of retinopathy and associated medical risk factors in type I (insulin-dependent) diabetes mellitus

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The North Jutland County Diabetic Retinopathy Study (NCDRS)

PURPOSE

This study set out to map the associations between retinal lesions, visual acuity (VA) and the presence of clinically significant macular oedema (CSMO) in diabetes subjects.

METHODS

This cross-sectional study comprised 656 type 1 and 328 type 2 diabetes subjects undergoing retinopathy screening in the County of North Jutland, Denmark. Numbers of specific retinal lesions were quantified from retinal photographic recordings. Associations between CSMO, number of specific retinal lesions and VA were established. The percentages of eyes with CSMO ascribed to retinal lesions were calculated.

RESULTS

The presence of CSMO, number of specific retinal lesions and VA were all significantly associated. The parameter with the highest statistical association with CSMO measured by Spearman's correlation coefficient was hard exudates (type 1: 0.524; type 2: 0.715), followed by microaneurysms (type 1: 0.298; type 2: 0.508), retinal haemorrhages (type 1: 0.227; type 2: 0.595), cottonwool spots (type 1: 0.207; type 2: 0.259) and VA (type 1: - 0.137; type 2: - 0,175).

CONCLUSIONS

All retinal lesions are significantly associated with CSMO and together can predict for up to 42.3% (in type 1 diabetes) and 64.3% (in type 2 diabetes) of CSMO cases.

[Diabetic retinopathy risk factors]

Diabetic retinopathy (DR) occurs in about 95% of patients with type 1 diabetes mellitus (DM) and in 60% of type 2 DM patients and it is the main cause of legal blindness in adult people. The aim of this manuscript was to review the main risk factors for DR. The major environmental risk factors are hyperglycemia, high blood pressure levels, and long-term duration of DM. However, not all patients will not develop DR, suggesting the presence of a genetic predisposition to DR, especially for severe forms of DR. Special strategies has been used to evaluate the genetic role in DR. Family studies shown that there is a familial aggregation of DR. Candidates genes have been studied (RAGE; VEGF; PPAR-delta; ICAM-1; ECA; ENPP 1; eNOS) and positive or negative associations with DR were demonstrated. Some chromosomes were also associated to DR in selected populations. Finally, genetic expression studies reinforce the association of candidate genes, or participation of others genes, with the presence of DR. DR is a common complication of DM and, along with non-genetic or environmental risk factors, the identification of genes related to DR could result in more specific and efficient DR treatment.

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 retinopathy differs with age at onset of diabetes in a population of patients with Type 1 diabetes

AIM

The VISS study (Vascular complications in South-east Sweden) investigates prevalence and incidence of vascular complications in a population with Type 1 diabetes, from a well-defined geographical area and followed from diagnosis with HbA1c measurement.

METHOD

The study population comprised all 440 patients with Type 1 diabetes onset before the age of 36 years, onset during 1983-1987, and at the time of onset living within the counties of Jönköping, Kalmar or Ostergötland. Retinopathy was examined with fundus photography 1994-1995, and classified according to a modified Airlie House protocol.

RESULTS

Fundus photographs from 390 patients were evaluated. In 277 (71%) patients no retinopathy was seen. The prevalence of retinopathy increased from 11% among patients < 5 years old at diabetes onset, to 48% among those 15-19 years old at diabetes onset, and then decreased to 30% for patients 30-35 years old at diabetes onset (P for chi2 for linear trend for all ages 0.017, for age at onset 0-19 years P = 0.0003), without corresponding differences in duration or HbA1c between patients with different onset age. Patients with HbA1c in the highest quartile (> 8.3% HbA1c) had a relative risk of 2.4 (95% confidence interval (CI) 1.7-3.2) of having any retinopathy compared with patients with lower HbA1c, and a relative risk of 7.1 (95% CI 3.0-16.7) of having other forms of retinopathy than microaneurysms.

CONCLUSION

In patients with diabetes duration of 6-13 years, the prevalence of retinopathy is clearly related to glycaemic control. Furthermore, the risk of retinopathy varies with different age at onset, independently of differences in duration or glycaemic control.

Diabetic retinopathy, visual acuity, and medical risk indicators: a continuous 10-year follow-up study in Type 1 diabetic patients under routine care

The objective of this study was to describe incidence and progression of diabetic retinopathy in relation to medical risk indicators as well as visual acuity outcome after a continuous follow-up period of 10 years in a Type 1 diabetic population treated under routine care. The incidence and progression of retinopathy and their association to HbA(1c), blood pressure, urinary albumin, serum creatinine levels, and insulin dosage were studied prospectively in 452 Type 1 diabetic patients. The degree of retinopathy was classified as no retinopathy, background, or sight-threatening retinopathy, i.e. clinically significant macular edema, severe nonproliferative, or proliferative retinopathy. Impaired visual acuity was defined as a visual acuity <0.5 and blindness as a visual acuity < or =0.1 in the best eye. In patients still alive at follow-up (n=344), 61% (69/114) developed any retinopathy, 45% (51/114) background retinopathy, and 16% (18/114) sight-threatening retinopathy. Progression from background to sight-threatening retinopathy occurred in 56% (73/131). In 2% (6/335), visual acuity dropped to <0.5 and in less than 1% (3/340) to < or =0.1. Patients who developed any retinopathy and patients who progressed to sight-threatening retinopathy had higher mean HbA(1c) levels over time compared to those who remained stable (P<.001 in both cases). Patients who developed any retinopathy had higher levels of mean diastolic blood pressure (P=.036), whereas no differences were seen in systolic blood pressure levels between the groups. Cox regression analysis, including all patients, showed mean HbA(1c) to be an independent risk indicator for both development and progression of retinopathy, whereas mean diastolic blood pressure was only a risk indicator for the incidence of retinopathy. Metabolic control is an important risk indicator for both development and progression of retinopathy, whereas diastolic blood pressure is important for the development of retinopathy in Type 1 diabetes. The number of patients who became blind during 10 years of follow-up was low.

Detection and prevalence of early diabetic retinopathy in juvenile diabetics with diabetes for 10 years or more

PURPOSE

To compare clinical examination using green light with clinical examination using white light in detecting early diabetic retinopathy (DR) in juvenile diabetic patients with disease for 10 or more years.

METHODS

All patients were examined clinically using both green light and white light to determine the presence of DR. Each patient underwent seven-field fundus photography, which was used as the defined standard against which the clinical examinations were compared and also to determine the prevalence of DR. Data on age at diagnosis, duration of diabetes mellitus, recent HbA1c levels, treatment for systemic hypertension and microalbuminuria were obtained from medical records.

RESULTS

When compared with the defined standard, fundal examination with green light was more sensitive, more specific and had higher predictive values than examination with white light in the detection of early DR. The overall prevalence of DR was 44%, which in all cases was classified as minimal to mild background DR. Patients with DR had significantly higher mean HbA1c levels than those without (p = 0.016). There was no significant association between the prevalence of DR and age at time of examination or diagnosis, duration of diabetes, patient gender, microalbuminuria levels or treatment for systemic hypertension.

CONCLUSION

Fundal examination with green light is better than white light in detecting early DR in juvenile diabetics with duration of disease of 10 years or more. Furthermore the presence of DR is associated with poorer diabetic control. Due to coincident lifestyle changes and the probability of long duration of disease, accurate detection of early DR in juvenile diabetics with diabetes for over 10 years is important.

The temporal development of retinopathy and nephropathy in type 1 diabetes mellitus during 15 years diabetes duration

In this prospective study, the 10- and 15-year incidence and course of retinopathy were examined in relation to medical risk indicators from 3.1 +/- 1.9 (mean -/+ SD) years diabetes duration and onwards in 29 adult type 1 diabetic patients treated under routine care. A total of 28 patients were followed for 10 years and 20 patients for 15 years diabetes duration. After 10 years diabetes duration, 11 patients had developed any retinopathy (ten patients background retinopathy and one patient clinically-significant macular oedema). After 15 years diabetes duration, 16 patients had developed any retinopathy (12 patients developed background retinopathy and four patients developed potentially sight-threatening retinopathy, i.e. clinically significant macular oedema (n = 2) or severe non-proliferative retinopathy (n = 2)). None of the patients developed proliferative retinopathy. No differences were seen in mean HbA1c values between patients without any retinopathy and patients with background retinopathy, whereas patients who developed potentially sight-threatening retinopathy had higher mean HbA1c levels than patients without any retinopathy. Patients who developed potentially sight-threatening retinopathy had higher levels of mean HbA1c both after 10 (9.7 +/- 1.6 vs 6.9 +/- 1.5%; P < 0.05) and 15 years diabetes duration (9.3 +/- 1.2 vs 7.1 +/- 1.3%; P < 0.05), compared to patients without any retinopathy. They also had higher levels of mean HbA1c than patients with background retinopathy after 15 years diabetes duration (9.3 +/- 1.2 vs 7.7 +/- 1.1%; P < 0.05). There were no differences in blood pressure levels between patients who developed retinopathy and those who did not. Only two patients developed clinical signs of nephropathy (urinary albumin 320-1590 mg/l) after 12 and 13 years diabetes duration, respectively. At those time points, both patients had already developed background retinopathy since 2 years. In conclusion, the present study shows that the incidence of retinopathy is associated with the duration of diabetes and that there is a strong association between the degree of metabolic control and development of potentially sight-threatening retinopathy. The study also indicates that the development of retinopathy does not seem to be associated with hypertension or clinical signs of nephropathy.

Prevalence of diabetic eye disease in an inner city population: the Liverpool Diabetic Eye Study

PURPOSE

To measure the population prevalence of diabetic eye disease in an inner city setting.

METHODS

As part of a systematic screening programme all adult diabetic patients in four general practices were invited to attend for slit-lamp biomicroscopy by a retinal specialist. Data on non-attenders were available from community-based photography.

RESULTS

Of 395 diabetic patients identified, 326 attended biomicroscopy with photographic data available on a further 31, giving a 90% compliance rate. Point prevalence of diabetes in the target population was 12.4/ 1000. Demographic data included: mean age 60 years (range 13-92 years); type of control: type I 49, type II insulin-requiring (IR) 40, type II non-insulin-requiring (NIR) 268. Prevalences were as follows: any retinopathy: of all diabetic patients 33.6%, type I 36.7%, type II IR 45.0%, type II NIR 31.3%; proliferative/ advanced: all 1.1%, type I 2.0%, type II IR 0, type II NIR 1.1%; clinically significant macular oedema: all 6.4%, type I 2.3%, type II IR 16.2%, type II NIR 5.7%. The percentage of patients with retinopathy requiring follow-up by an opthalmologist was 4.5%, and 9.2% had macular exudates within 1 disc diameter of fixation or significant circinate maculopathy. Sight-threatening diabetic eye disease (STED) was found in 13.4%. A visual acuity of < or = 6/24 in the better eye occurred in 12 (3.4%) patients and of < or = 6/60 in the better eye in 3 (0.8%).

CONCLUSIONS

Compared with previous population studies, prevalences appear to have declined in type I, but remain high in type II diabetic patients and especially in those requiring insulin.

Prevalence and risk factors for diabetic retinopathy among Omani diabetics

AIMS

To study the prevalence of diabetic retinopathy in a population of patients attending a diabetic clinic and to evaluate the medical risk factors underlying its development.

METHODS

500 randomly selected diabetic patients attending the diabetes clinic in Al Buraimi hospital were referred to the ophthalmology department where they were fully evaluated for the absence or presence of retinopathy. Any retinopathy present was graded as mild non-proliferative retinopathy (NPR), moderate-severe NPR, and proliferative retinopathy. Several risk factors were then evaluated in order to delineate those related to occurrence of retinopathy in general as well as to the different grades of retinopathy in particular.

RESULTS

Diabetic retinopathy was detected in 212 patients (42.4%), with mild NPR present in 128 patient (25.6% of the total population), moderate-severe NPR in 20 patients (4%), and proliferative diabetic retinopathy present in 64 patients (12.8%). Factors significantly related to occurrence of retinopathy were age of the patient, duration of diabetes, presence of ischaemic heart disease, presence of hypertension, a high fasting capillary glucose level as well as elevated serum levels of urea, creatinine, cholesterol, and triglycerides. After adjustment for covariates, it was found that duration of diabetes was the only risk factor associated with mild NPR, while high diastolic blood pressure and high levels of serum creatinine, cholesterol, and triglycerides were significantly associated with the occurrence of proliferative retinopathy.

CONCLUSIONS

In addition to glycaemic control, lowering of blood lipids as well as diastolic blood pressure (in hypertensive patients) may be effective in lowering the incidence of retinopathy in compromised patients.

Inverse relationship between GAD65 antibody levels and severe retinopathy in younger type 1 diabetic patients

Several risk factors for severe non-proliferative and proliferative retinopathy in type 1 diabetes mellitus have been proposed without explaining the rapid progression of retinopathy in some patients. Since GAD65 autoantibodies (GAD65Abs) are detected against glutamic acid decarboxylase (GAD), which is mainly expressed in islets and nervous tissue in type 1 diabetic patients, the aim of the present investigation was to test the hypothesis whether GAD65Abs are associated with rapidly progressing severe retinopathy. Patients with severe non-proliferative or proliferative retinopathy (n = 27) were compared with another group, which in spite of long diabetes duration had no or only mild signs of retinopathy (n = 28). GAD65Abs were analysed in a radioimmunoassay using in vitro translated human GAD65, and the levels were expressed as an index in relation to positive and negative reference samples. Using a cut-off level representing the 99th percentile of normals, 6/27 (22%) with and 9/28 (32%) without severe retinopathy were considered GAD65Ab positive. Although there was no difference in the number of GAD65Ab positive patients, the GAD65Ab levels were lower in patients with (0.30; 0.11-0.64) than without (0.68; 0.34-1.12) severe retinopathy (P = 0.03). The patients were also subjected to HLA-DR and DQ typing by PCR and hybridization with oligospecific probes. DQ2/8 was more common in patients with (56%) than without (29%) severe retinopathy (P = 0.05), but DQ2/8 could not account for the lower GAD65Ab levels in patients with severe retinopathy. It is concluded that GAD65Ab levels are inversely correlated with severe retinopathy in young type 1 diabetic patients.

Prevalence of diabetic retinopathy in patients with diabetes mellitus diagnosed after the age of 70 years

AIMS/BACKGROUND

A hospital based prevalence study was undertaken to estimate the prevalence of diabetic retinopathy (DR) in patients diagnosed as having diabetes mellitus after the age of 70 years. The prevalence of visually threatening retinopathy at the time of diagnosis of diabetes was also determined. The association between prevalence of DR and duration of diabetes mellitus, mode of treatment, HbA1c levels, presence of hypertension, and sex of patient was examined and a comparison was drawn between this study and earlier prevalence studies of DR in older type II diabetics.

METHODS

Using data on the Irish Diabetic Retinopathy Register located in the Mater Misericordiae Hospital, Dublin, all patients who were diagnosed as having type II diabetes mellitus after the age of 70 years were invited to attend for ophthalmic review. Medical records were examined to determine the duration of diabetes mellitus, mode of treatment, recent HbA1c levels, and the presence of systemic hypertension.

RESULTS

Of the 150 patients examined, 21 (14%) had some form of DR and 10 of these patients (6.6%) had visually threatening retinopathy or previously treated visually threatening retinopathy. Five patients (3.3%) presented with visually threatening retinopathy at the time of diagnosis of diabetes. Those patients with DR had a significantly higher median duration of diabetes (5.0 years) compared with those patients without DR (3.5 years). A significantly higher proportion of patients with DR required treatment with insulin and a correspondingly lower proportion of patients without DR were controlled on diet alone. There was no significant association between prevalence of DR and HbA1c levels, systemic hypertension, or sex of patient. There was a lower overall prevalence of DR in comparison with earlier studies.

CONCLUSIONS

The prevalence of DR in these elderly type II diabetics is lower than than previously reported in patients with type II disease but a small percentage of patients had visually threatening retinopathy at presentation. Longer duration of diabetes and insulin use were associated with a significantly increased prevalence of DR. All elderly type II diabetic patients require thorough ophthalmic examination near to the time of first presentation and thereafter at regular intervals.

Prevalence of diabetic retinopathy in relation to age at onset of the diabetes, treatment, duration and glycemic control

To study the frequency of diabetic retinopathy in relation to age at diagnosis, treatment, duration of diabetes and glycemic control as measured by means of HbA1c levels, we performed a cross-sectional, registered-based study in the Helsingborg area of southern Sweden, comprising 2232 diabetic patients. Of the known diabetic population < 75 years old, approximately 70% were estimated to be included. We graded retinopathy according to the alternative classification of the Wisconsin study. With an age at diagnosis < 30 years (19% of patients) the prevalence of retinopathy was 64%, whereas with an age at diagnosis > or = 30 years the prevalence of retinopathy was 57% in insulin-treated, and 26% in non-insulin treated patients. Levels of glycated hemoglobin and duration of diabetes were associated with retinopathy in the group with younger onset. In the older-onset group, there was a relationship between retinopathy and duration of diabetes and insulin treatment; glycated hemoglobin had a relationship which was of borderline significance with any retinopathy, but clearly significant with the pooled group: severe non-proliferative, proliferative retinopathy and/or macular edema. Hyperglycemia and duration of diabetes were thus associated with retinopathy in both younger- and older-onset diabetes, but hyperglycemia less so in the older-onset group.

The progression of retinopathy over 2 years: the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study

This study examined potential risk factors for the incidence and progression of retinopathy in a large representative cohort of childhood onset insulin-dependent diabetic patients. Participants in the Epidemiology of Diabetes Complications (EDC) Study underwent a full clinical examination at baseline and again at a 2-year follow-up. Retinopathy status was ascertained using stereo fundus photographs graded according to the modified Airlie House System. The study population is based on a large cohort of childhood-onset insulin-dependent diabetic patients, seen within 1 year of diagnosis at the Children's Hospital of Pittsburgh between January 1950 and May 1980. A total of 657 subjects participated at baseline (1986-1988), with 80% of eligible survivors taking part in the follow-up examination. This report concerns risk factors associated with the progression of diabetic retinopathy over a 2-year period, and the interaction of these factors with the presence of nephropathy. Analyses showed that baseline diastolic blood pressure was significantly associated with the incidence of any retinopathy, while glycosylated hemoglobin, baseline severity of retinopathy, serum triglycerides, and, to a lesser extent, higher levels of low-density lipoprotein (LDL) cholesterol and fibrinogen were associated with the progression of retinopathy. Progression to proliferative retinopathy was related to higher LDL cholesterol, fibrinogen, serum triglycerides, albumin excretion rate, and glycosylated hemoglobin (GHb). Risk factors varied with the presence of nephropathy. In the absence of nephropathy, GHb was a significant predictor of progression, whilst this was not the case in the presence of nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired contrast sensitivity in adolescents and young type 1 (insulin-dependent) diabetic patients with microalbuminuria

We compared neurosensorial visual function by psychophysical tests (macular recovery time and contrast sensitivity) in two well matched groups of young Type 1 (insulin-dependent) diabetic patients with micro- and normoalbuminuria, respectively. The patients had normal visual acuity (> or = 1.0) and either no retinopathy or non-proliferative retinopathy. Thirty patients with microalbuminuria (albumin excretion > or = 15 micrograms/min in a least two out of three timed overnight urine samples) were matched (age, diabetes duration, mean one-year HbA1c, gender) with normoalbuminuric (n = 27) patients. Retinopathy (50 degree colour fundus photography) was assessed by counting microaneurysms and hemorrhages as 'red spots'. Contrast sensitivity was examined for the spatial frequencies of 1.5, 3, 6, 12 and 18 cycles per degree (cpd). Macular recovery time (nyctometry) refers to the time-related (2 min) ability of the retina to regain visual acuity following exposure to bright light (photostress). Contrast sensitivity score was reduced in patients with microalbuminuria compared to those without; 18 cpd (mean and 95% confidence intervals): [4.2 (3.8-4.7) vs 5.0 (4.6-5.4), p = 0.03]. Macular recovery performance was not significantly reduced: [21.0 arbitrary units (17.5-24.6) vs 26.0 (22.6-30.7), p = 0.12]. We conclude that impaired contrast sensitivity independent of background retinopathy is shown in a group of young Type 1 (insulin-dependent) diabetic patients with low-grade microalbuminuria compared to a group of patients with normoalbuminuria.

A 5-year follow-up study on the incidence of retinopathy in type 1 diabetes mellitus in relation to medical risk indicators

OBJECTIVES

The aim of the present study was to describe the 5-year incidence of retinopathy in type 1 diabetes mellitus and to characterize risk indicators for the development and progression of retinopathy.

DESIGN

A cross-sectional study of type 1 diabetic patients taken care of at a medical department.

SETTING

All type 1 diabetic patients attending the Department of Internal Medicine, University Hospital, Lund, during a 2-year period were offered ophthalmological examination.

SUBJECTS

A total of 396 out of 461 (85.9%) initially examined type 1 diabetic patients formed the basis for this 5-year follow-up study.

MAIN OUTCOME MEASURES

The degree of retinopathy was based on fundus photography or biomicroscopy. Degree of metabolic control was assessed by HbA1c levels, signs of nephropathy by albumin creatinine clearance ratio and urinary albumin levels. Blood pressure was measured in the supine position. Duration of diabetes, age, and insulin dosage were registered.

RESULTS

The incidence of retinopathy was 47.2% and progression from background to severe retinopathy occurred in 41%. Risk indicators for the development of retinopathy were duration of diabetes (P < 0.001), degree of metabolic control (P < 0.001), insulin dosage (P < 0.05) and signs of nephropathy based on measurements of albumin creatinine clearance ratio (P < 0.01) and urinary albumin concentration (P < 0.05). Two risk indicators could be identified for progression of retinopathy, i.e. the degree of metabolic control (P < 0.01) and diastolic blood pressure (P < 0.05).

CONCLUSIONS

The results suggest that apart from poor metabolic control, development of retinopathy in type 1 diabetes is associated with long diabetes duration and clinical signs of diabetic nephropathy. Progression of retinopathy is associated with poor metabolic control and elevated diastolic blood pressure levels.

The five-year incidence of blindness after introducing a screening programme for early detection of treatable diabetic retinopathy

The incidence of moderate visual impairment and blindness due to diabetic retinopathy was studied 5 years after introducing a screening system for early detection of treatable retinopathy. Photocoagulation was performed in patients with clinically significant macular oedema, severe preproliferative, and proliferative retinopathy. Eighty-eight percent of 470 Type 1 and 88% of 388 Type 2 diabetic patients were still available for follow-up. In the Type 1 group, the five-year incidence of blindness and moderate visual impairment were 0.5% and 1.2%, respectively. Corresponding figures for the Type 2 diabetic patients were 0.6% and 1.7%, respectively. The majority of patients with loss of vision had severe retinopathy at baseline. Among those who entered the screening programme with no or mild retinopathy, loss of vision occurred in only one of the Type 1 and four of the Type 2 diabetic patients. It is concluded that the risk for visual impairment and blindness due to diabetes can be substantially reduced by using programmes for early detection of and effective treatment of diabetic retinopathy.

Quality of centralized diabetes care: a population-based study in the German Democratic Republic 1989-1990

The efficacy of care in the centralized diabetes care system in the former German Democratic Republic was evaluated on the basis of the recommendations of the St. Vincent Declaration. Eighty-three per cent (n = 190, 46% women) of all insulin-treated diabetic patients aged 16-60 years who were registered in one district diabetes care unit were examined. Of these, 131 patients had type 1 (insulin-dependent) diabetes (69%) and 59 type 2 (non-insulin-dependent) diabetes (31%). All patients were on animal insulin and 96% (n = 187) had conventional therapy consisting of fixed insulin dose and a fixed diet. Levels of glycosylated haemoglobin (normal 4.15%, SD 0.54) were 6.3 +/- 1.3% in type 1 and 7.4 +/- 1.7% in type 2 diabetics. Retinopathy was found in 35% of type 1 (proliferative 3.8%) and 23% of type 2 patients (proliferative 3.4%). No patient was blind. Screening for nephropathy identified 29% of type 1 and 47% of type 2 diabetics as having albuminuria > 20 mg/l in early-morning urine. The prevalence of hypertension was 31% and 69% for type 1 and type 2 patients respectively. Foot ulcers were found in 2.1% and lower limb amputations in 2.1%. The incidence of severe hypoglycaemia (except in pregnancy) was 0.07 per patient per year. This study shows that the diabetes care system was effective and the winding up of this system with the reunification of Germany was not a medical necessity. However, the system failed to establish an integrated regime with regional general practitioners for the effective treatment of hypertension.

Irreversible progression of severe retinopathy in young type I insulin-dependent diabetes mellitus patients after improved metabolic control

The impact of metabolic control on the development of rapidly progressive severe retinopathy was studied in 14 young type I insulin-dependent diabetes mellitus (IDDM) patients. Glycosylated hemoglobin (HbAlc) levels 45 months prior to and 12 months after the diagnosis of retinopathy were compared with HbAlc levels in 17 type I IDDM patients with no or minimal background retinopathy, matched for age and duration of diabetes. HbAlc levels were generally higher in patients with severe retinopathy (p less than 0.05) from 39 months until 6 months before the diagnosis of retinopathy. Thereafter, there was a gradual decrease in HbAlc levels reaching the same level as in control patients 6 months after diagnosis of retinopathy. Patients with severe retinopathy required higher doses of insulin prior to the diagnosis of retinopathy (p less than 0.05), but the insulin requirement decreased, and 12 months afterward, the insulin dosage was similar to patients with background retinopathy. Systolic blood pressure levels were slightly increased and higher in patients with severe retinopathy compared with control patients from 18 months before to diagnosis of retinopathy (p less than 0.05). Diastolic blood pressure levels likewise differed at 18 and 12 months before and at the time of diagnosis of retinopathy as well as 12 months afterward (p less than 0.05); however, no differences were seen in urinary albumin or serum creatinine levels between the groups. Thus, years of poor metabolic control, drastically improved, preceded the development of irreversible severe retinopathy in these young type I IDDM patients.

Cost-effectiveness of the screening and treatment of diabetic retinopathy. What are the costs of underutilization?

Diabetic retinal disease remains a leading cause of visual disability among those of working age. Controlled trials have demonstrated that timely diagnosis and photocoagulation treatment can reduce significantly the likelihood of visual impairment in affected diabetic patients. Using a prospective simulation model, we show that an annual screening and treatment program saves thousands of years of vision and reduces medical expenditures over the lifetime of a cohort of Swedish Type I diabetic patients.

Is hypertension a major independent risk factor for retinopathy in type 1 diabetes?

Hypertension is an established risk factor for retinopathy. Whether it is an independent risk factor or acts only by association with nephropathy is not known. Therefore, we studied 273 Type 1 diabetic patients. They were divided into four groups. Group 1 (n = 55) were normotensive and normoalbuminuric, group 2 (n = 51) had hypertension but were normoalbuminuric, group 3 (n = 33) had nephropathy but were normotensive, and group 4 (n = 134) had nephropathy and hypertension. Hypertensive patients with normoalbuminuria (blood pressure 146 +/- 19 (+/-SD)/87 +/- 12 mmHg) had the same prevalence of retinopathy as normoalbuminuric normotensive patients (123 +/- 12/75 +/- 5 mmHg). Hypertensive nephropathic patients (blood pressure 147 +/- 18/87 +/- 8 mmHg) had more retinopathy than hypertensive normoalbuminuric patients despite similar blood pressure (normal retina/advanced retinopathy: 3%/73% vs 46%/17%, p less than 0.001). Nephropathic normotensive patients had worse retinal changes than hypertensive normoalbuminuric patients (19%/49%, p less than 0.001) but fewer than the nephropathic hypertensive patients p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes education in the USSR: how to begin?

To determine patients' attitudes towards diabetes education in the Soviet Union, a questionnaire was distributed throughout the country. From 10,000 completed forms, returned from all regions of the USSR, 2000 were analysed in detail. Responders represented all age and social groups, but patients with shorter duration of diabetes, and women, responded more readily. More than 41% of patients were unaware of the type of diabetes they had, the actual proportions of Type 1 and Type 2 diabetes among respondents being 31 and 63%. Rates of chronic complications derived from patients' answers suggest a high rate of underestimation by local physicians. Only 17% of Type 1 and 8% of Type 2 diabetic patients believed that they knew enough about diabetes, and 99.9% of all respondents wanted to learn more about their disease. Independently of the type of diabetes and educational level, patients would accept the information on diabetes from periodicals (63-68%), television (48-63%), booklets for patients (29-31%), as well as attending diabetes courses or classes (30-38%). They expressed preference for teaching conducted by physicians (74-85%) rather than nurses (1-4%). The main areas of interest for Type 1 diabetic patients were technical devices, (artificial pancreas and insulin pumps (85%] and late diabetic complications (78%), and for patients with Type 2 diabetes late complications (84%) and diet (72%). Some respondents (20-25%) expected the use of herbs and other 'non-traditional' methods to be effective in treatment and curing of diabetes. The least requested topics were acute complications (18-34%) and metabolic self-monitoring (0.025%).(ABSTRACT TRUNCATED AT 250 WORDS)

The epidemiology of foot lesions in diabetic patients aged 15-50 years

All diabetic patients aged 15-50 years (n = 395) in the county of Umeå (population 118,500) were invited to have a standardized foot examination and 380 (96%) attended. Three-quarters (78%) had Type 1 diabetes, 20% Type 2 diabetes, and 1% secondary diabetes. They were compared with 100 healthy control subjects. Both Type 1 and Type 2 diabetic patients had slight or moderate loss of forefoot arches more often than control subjects (57% and 60% vs 31%, p less than 0.001). Callosities were not significantly more common in diabetic patients than in control subjects. Lesions observed on the lower legs and feet of the Type 1 and Type 2 diabetic patients were Melin's shin spots (33% and 39%), dry feet (33% and 29%), yellow toenails (27% and 31%), purpura (9% and 5%), ulcers (3% and 0%), necrobiosis (3% and 0%), and diabetic osteopathy (2% and 0%). Intermittent claudication was present in 1% and 3%, respectively. Three Type 1 diabetic patients had undergone below-knee amputation. Two of the control subjects had Melin's shin spots. With the exception of necrobiosis which was only found in women with Type 1 diabetes and Melin's shin spots which were twice as common in diabetic men as women, whether Type 1 or Type 2, lesions were equally distributed between the sexes. Sensory thresholds for vibration, perception, and pain were significantly elevated in Type 1 diabetic patients with dry feet, fallen forefoot arches or hammer toes compared with those without. They were not increased in Type 2 diabetic patients or control subjects with these lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Putative risk factors associated with retinopathy in patients with diabetes diagnosed at or after 30 years of age

In a cross-sectional study of diabetic patients diagnosed at or after 30 years, and with different stages of retinopathy, factors such as duration of diabetes, treatment mode, metabolic control, blood pressure, and clinical signs of nephropathy were examined. The different stages of retinopathy used were absence of retinopathy, simplex, and severe retinopathy. Patients with simplex and severe retinopathy were older than those without retinopathy (p less than 0.001, and p less than 0.01, respectively). They also had a longer duration of diabetes (p less than 0.001), and were more often treated with insulin (p less than 0.001) and in larger doses (p less than 0.001). Their glycosylated haemoglobin levels were higher (p less than 0.01). Their systolic blood pressure was higher (p less than 0.01), but the diastolic blood pressure did not differ, and the number of patients treated for hypertension was similar in all groups. Albumin clearance was higher (p less than 0.01 and p less than 0.001), as were urinary albumin levels (p less than 0.001). The only variables that distinguished patients with simplex from those with severe retinopathy were albumin clearance (p less than 0.01) and urinary albumin levels (p less than 0.05).