Biomedical subjects

B E Klein

Publications and source records attributed to B E Klein.

At least 217 records · Page 12Linked to original sources

PubMed1990

The Wisconsin epidemiologic study of diabetic retinopathy: an update.

Population-based epidemiologic data on the incidence and progression of diabetic retinopathy are important in developing approaches to preventing diabetic retinopathy, in medical counselling and rehabilitative services. The objectives of the Wisconsin Epidemiological Study of Diabetic Retinopathy were as follows: (1) to describe the prevalence, incidence, and progression of diabetic retinopathy and its component lesions, and to determine the incidence of visual impairment in a large population-based cohort; and (2) to determine the relationships between incidence and progression of diabetic retinopathy and risk factors in this cohort. Grading of stereoscopic fundus photographs was performed at the University of Wisconsin Fundus Photograph Reading Centre for photographs from both the baseline examination in 1980-1982 and follow-up examination four years later. Insulin-taking persons diagnosed to have diabetes before 30 years of age had the highest prevalence (71%), four-year incidence (59%) and progression to proliferative diabetic retinopathy (11%) while older-onset persons diagnosed to have diabetes at or after 30 years of age and not using insulin had the lowest prevalence (39%), incidence (34%) and progression to proliferative diabetic retinopathy (3%). These incidence data indicate that a substantial proportion of older onset diabetic people, a group previously thought to be protected from retinopathy, developed it during the four-year interval and underscores the need for careful ophthalmologic examination.

Adult↗

PubMed1990

Wisconsin Epidemiologic Study of Diabetic Retinopathy. XII. Relationship of C-peptide and diabetic retinopathy.

The relationship between plasma C-peptide and the frequency and severity of diabetic retinopathy was examined in a population-based study in Wisconsin in 1984-1986. Individuals with younger- (n = 835) and older- (n = 940) onset diabetes were included. C-peptide was measured by radioimmunoassay with Heding's M1230 antiserum. Retinopathy was determined from stereoscopic fundus photographs. The highest frequencies and most severe retinopathy were found in insulin-using individuals with undetectable or low plasma C-peptide (less than 0.3 nM), whereas the lowest frequencies of retinopathy were found in older-onset overweight individuals not using insulin. In older-onset individuals using insulin, having no detectable C-peptide was significantly associated with the presence of proliferative retinopathy. Otherwise, within each group (younger onset using insulin, older onset using insulin, and older onset not using insulin), after controlling for other characteristics associated with retinopathy, there was no relationship between higher levels of C-peptide and lower frequency of or less severe retinopathy.

C-Peptide↗

PubMed1990

Is insulinlike growth factor I associated with diabetic retinopathy?

Insulinlike growth factor I (IGF-I) is the mediator of the growth-promoting effects of growth hormone and has been suspected of playing a role in the pathogenesis of proliferative diabetic retinopathy (PDR). However, previous attempts to correlate IGF-I levels with PDR have yielded conflicting results. We determined IGF-I levels in a large population-based study of 682 early-onset (diagnosed before 30 yr of age) adult (greater than or equal to 18 yr old) insulin-taking diabetic subjects. PDR was found in 25% of the population. IGF-I levels were measured by radioimmunoassay. The mean serum level of IGF-I was 277 +/- 108 micrograms/L (mean +/- SD). Spearman rank correlations showed statistically significant negative correlations between IGF-I levels and age (r = -0.51, P less than 0.0001), duration of disease (r = -0.36, P less than 0.0001), and glycosylated hemoglobin (r = -0.09, P less than 0.05). There was a significant trend (P less than 0.001) toward decreasing risk of PDR with increasing IGF-I. However, after controlling for duration of diabetes, glycosylated hemoglobin, diastolic blood pressure, and the presence of proteinuria and/or creatinine greater than or equal to 265 microM in a multiple logistic regression model, IGF-I was not significantly associated with PDR. These data suggest that IGF-I may not be a risk factor for the development of PDR.

Adolescent↗

PubMed1990

Effect of pregnancy on progression of diabetic retinopathy.

A prospective study was undertaken to determine the effect of pregnancy on diabetic retinopathy. Insulin-taking diabetic women were enrolled; one group was comprised of pregnant women, the other group was comprised of women who were not pregnant. Women were evaluated on referral and again in the postpartum period. The severity of diabetic retinopathy was based on grading of fundus photographs of seven standard photographic fields. The glycosylated hemoglobin, duration of diabetes, current age, diastolic blood pressure, number of past pregnancies, and current pregnancy status were evaluated as risk factors for progression of diabetic retinopathy. After adjusting for glycosylated hemoglobin, current pregnancy was significantly associated with progression (P less than 0.005, adjusted odds ratio 2.3). Diastolic blood pressure had a lesser effect on the probability of progression. The findings from this study indicate that pregnancy and level of glycemia are associated with progression of diabetic retinopathy.

Adult↗

PubMed1990

Is menarche associated with diabetic retinopathy?

The goal of this study was to evaluate the association between menarchal status and diabetic retinopathy. Diabetic retinopathy was present in 51 of 129 females; 7 were premenarchal, and 44 were postmenarchal. The range of severity of retinopathy was greater in the postmenarchal group. In multivariate analyses, duration of diabetes, menarchal status, and diastolic blood pressure were associated with the prevalence of diabetic retinopathy. After partitioning the duration of diabetes into years before and years after menarche, both were significant, but the number of years of diabetes after menarche was more strongly associated. At a 4-yr follow-up examination, more postmenarchal than premenarchal females had progression of their retinopathy (P = 0.06). These data suggest that stage of sexual development, as reflected by menarchal status, is associated with the presence and possibly the risk of progression of diabetic retinopathy.

Adolescent↗

PubMed1990

Oral contraceptives in women with diabetes.

We evaluated the association of oral contraceptive use with the presence and severity of diabetic retinopathy, hypertension, and glycosylated hemoglobin in women of childbearing age who have diabetes. Neither current or past use nor number of years of use of oral contraceptives was associated with severity of retinopathy, hypertension, or current glycosylated hemoglobin. In conclusion, further study of various birth control methods in young women of childbearing age should be considered.

Adolescent↗

PubMed1990

Ocular problems in older Americans with diabetes.

Data from the Wisconsin Epidemiologic Study of Diabetic Retinopathy from persons with diabetes of older onset whose average age was 65.4 years indicate that 9.9% of the men and 13.3% of the women had some degree of visual impairment, and 1.4% of men and 1.7% of women were legally blind (with an visual acuity of 20/200 or worse in the better eye). Poorer visual acuity was strongly associated with increasing duration of diabetes, but age was also an important factor, with rates of legal blindness increasing markedly after the seventh decade of life in groups of any duration. Conditions responsible for legal blindness were diabetic retinopathy or maculopathy, cataracts, glaucoma, and macular degeneration. Incidence of blindness 4 years after the initial evaluation was related to insulin use, younger age at examination, longer duration of diabetes, and more severe retinopathy at baseline. Worsening of vision was related to higher levels of glycosylated hemoglobin and the presence of macular edema on diabetic retinopathy at baseline. These data indicate that there is a high prevalence of ocular problems among people with diabetes of older onset. The practitioner should suggest to these patients that, soon after the diagnosis of diabetes, they have an ophthalmologic evaluation to determine whether asymptomatic problems are present. This action may lead to timely intervention to prevent loss of vision in some patients.

Age Factors↗

PubMed1990

Neuroretinal rim area in diabetes mellitus.

Neuroretinal rim area (NRA) may indicate the amount of viable optic nerve tissue. Changes in the NRA have been found to occur in people with glaucoma. We sought to determine whether there were effects of retinopathy and intraocular pressure (IOP) on NRA in eyes of people with diabetes. Measurements of optic discs and cups were taken from 35-mm stereoscopic slides taken with a Zeiss fundus camera. The photographs were taken during a population-based study. The difference between disc and cup area was taken to be the NRA. Median photographic NRA from 2085 right eyes was 10.5 mm2. In younger- and older-onset persons, NRA showed a tendency to increase with age and, inconsistently, with the severity of diabetic retinopathy; it decreased with increasing IOP in older-onset persons not taking insulin. The cohort was reevaluated 4 yr later. NRA increased in all groups. Measurements from photographs taken of a nondiabetic comparison group showed no change over the same interval. These data suggest that NRA may be affected by diabetes. This could be due to nerve swelling.

Adolescent↗

PubMed1990

Diabetic retinopathy: possible etiological role of hyperglycemia.

Retinopathy in young people with diabetes is uncommon before puberty. It does, however, appear during the adolescent years. Although the specific mechanisms that trigger the development of this complication are poorly understood, recent evidence suggests that hyperglycemia as reflected by elevated glycosylated hemoglobin is associated with the development and progression of diabetic retinopathy. Because the management of these patients relies heavily upon the compliance of the patient, education as to the nature, treatment and sequelae of diabetes and its complications are essential parts of the medical management of these patients.

Adolescent↗

PubMed1989

The Wisconsin Epidemiologic Study of Diabetic Retinopathy. IX. Four-year incidence and progression of diabetic retinopathy when age at diagnosis is less than 30 years.

Population-based epidemiologic data on the incidence and progression of diabetic retinopathy are important in medical counseling and rehabilitative services and for developing approaches to preventing diabetic retinopathy. We performed a population-based study in southern Wisconsin of insulin-taking diabetic persons diagnosed before 30 years of age. Of the 271 who had no retinopathy at the first visit, 160 (59%) developed it by the time they were reexamined four years later, and 75 (11%) of the 713 free of proliferative diabetic retinopathy developed it. Overall, worsening of retinopathy occurred in 41% of the population, whereas improvement occurred in only 7%. The incidence of proliferative retinopathy rose with increasing duration until 13 to 14 years of diabetes, thereafter remaining between 14% and 17%. These incidence data underscore the need for careful ophthalmologic follow-up of these people.

Adolescent↗

PubMed1989

The Wisconsin Epidemiologic Study of Diabetic Retinopathy. X. Four-year incidence and progression of diabetic retinopathy when age at diagnosis is 30 years or more.

The four-year incidence and progression of retinopathy were investigated in a population-based sample of people with diabetes diagnosed at 30 years of age or older. For insulin users, 73 (47%) of the 154 who did not have any retinopathy at the first visit developed it in the four-year interval, and 31 (7%) of the 418 free of proliferative retinopathy developed it. Worsening of retinopathy occurred in a total of 34% (142/418). For nonusers of insulin, corresponding rates were 34% (110/320) for incidence of any retinopathy, 2% (11/486) for developing proliferative retinopathy, and 25% (121/486) for worsening. These population-based data clearly indicate the risk of retinopathy worsening in a short interval (four years) in a large proportion of people with older-onset diabetes, a group previously thought to be relatively protected from retinopathy. Such patients who make up the largest proportion of diabetic patients in the United States need examination when diabetes is first diagnosed and regular follow-up.

Adult↗

PubMed1989

The relationship of retinal microaneurysm counts to the 4-year progression of diabetic retinopathy.

The relationship of retinal microaneurysms to the progression of diabetic retinopathy over a 4-year period was examined in a population-based sample of diabetic persons. The number of microaneurysms in color stereoscopic fundus photographs of seven standard fields was counted in the eyes of diabetic persons (n = 236) who had only microaneurysms in photographs at the baseline examination. If only one eye was involved (n = 121), the mean number of microaneurysms was 2.3; with bilateral involvement (n = 115), the mean was 9.3 in the more involved eye. The number of microaneurysms at the baseline examination was positively associated with significant progression of retinopathy. This relationship remained after controlling for the level of glycosylated hemoglobin. These data suggest that the number of microaneurysms at baseline is an important predictor of progression of diabetic retinopathy. Microaneurysm counts may prove to be a useful early end point in clinical trials.

Adult↗

PubMed1989

The Wisconsin epidemiological study of diabetic retinopathy: a review.

The WESDR has provided precise estimates of the prevalence, and 4-year incidence and progression of diabetic retinopathy. It has provided evidence of a possible causal relationship between specific risk factors, such as hyperglycemia and the development and progression of retinopathy. Our data support current recommendations for ophthalmologic examinations for people with diabetes. In 1990 we will reexamine the cohort to determine the 10-year incidence and progression of diabetic retinopathy, macular edema, and visual impairment.

Diabetes Mellitus, Type 1↗

PubMed1989

The Wisconsin epidemiologic study of diabetic retinopathy. XI. The incidence of macular edema.

As part of a population-based study of diabetes mellitus, the 4-year incidence of macular edema and its relationship to various risk factors was examined in a group of younger onset insulin-taking persons (n = 610) and older onset persons (n = 652). The presence of macular edema at the baseline and follow-up examinations was determined from gradings of stereoscopic fundus photographs. The overall incidence of macular edema in the younger onset group was 8.2% (50/610); in the group of older onset persons using insulin, 8.4% (23/273) and in the group of those not using insulin, 2.9% (11/379). The incidence of macular edema was associated with higher level of glycosylated hemoglobin, longer duration of diabetes, and more severe retinopathy at the baseline examination in both younger and older onset groups. These data provide accurate population-based estimates of incidence of macular edema, and suggest that the level of glycemia is a significant risk factor for the development of macular edema.

Adolescent↗

PubMed1989

Are seven standard photographic fields necessary for classification of diabetic retinopathy?

Stereoscopic fundus photography of seven fields has become standard procedure for detecting diabetic retinopathy. However, the question has arisen as to whether adequate detection of retinopathy can be achieved with fewer fields. This question was investigated in a population-based study of 2694 diabetic persons. Retinopathy levels derived from the detailed grading of all seven fields were compared with those derived from combinations of two, three or four fields, the data for these being selected from the grading of the full seven fields. For eight retinopathy levels, the rate of agreement with seven fields ranges from 80% for two fields to 91% for four fields. For four retinopathy levels, agreement increases to 85 to 95%. The rate of agreement also varies with the specific retinopathy level, with level 65 being especially sensitive to the number of fields. The sensitivity of two to four fields compared to seven fields for detecting any retinopathy varies from 87 to 95%. For detecting proliferative retinopathy, sensitivity varies from 74 to 90%, and for Diabetic Retinopathy Study high-risk characteristics, it varies from 81 to 91%. Analysis of two groups of 50 eyes in which the combinations of fields were graded independently shows a small but nonsignificant effect of field overlap. These results indicate that in some situations, fewer fields may be adequate.

Diabetic Retinopathy↗

PubMed1989

Is blood pressure a predictor of the incidence or progression of diabetic retinopathy?

The relationship between blood pressure and the 4-year incidence and progression of diabetic retinopathy was examined in a population-based study in Wisconsin. Younger- (n = 891) and older-onset (n = 987) persons participating in baseline and follow-up examinations were included. Blood pressure was measured using the Hypertension Detection and Follow-up Program protocol. Retinopathy was determined from stereoscopic fundus photographs. In the younger-onset group, comparing the highest with the lowest quartile of systolic blood pressure, the relative risk for developing any diabetic retinopathy was 1.8 and for diastolic blood pressure it was 1.2; for progression of diabetic retinopathy, it was 1.1 and 1.3 for systolic and diastolic blood pressure, respectively. After controlling for other risk variables, systolic blood pressure remained a significant predictor of the incidence of diabetic retinopathy; diastolic blood pressure was of borderline significance in predicting progression in the younger-onset group. Blood pressure was not related to incidence or progression of retinopathy either in the older-onset group using insulin or the older-onset group not using insulin.

Age Factors↗

PubMed1989

Optic disc cupping: prevalence findings from the WESDR.

Increased cupping of the optic disc is considered to be an indication of pressure-related damage of the optic nerve. This paper explores the relationship of intraocular pressure and cupping in persons with diabetes mellitus, a group of people whose optic nerves may be more susceptible to the effects of intraocular pressure. Stereoscopic fundus photographs of the seven standard fields were obtained in all persons participating in the Wisconsin Epidemiologic Study of Diabetic Retinopathy at the time of the initial prevalence survey. Measurements of disc and cup diameters in the vertical and horizontal meridia were made by two trained graders. Cup-to-disc ratios were computed for both diameters of each eye and the mean of the two gradings was used. A history of glaucoma was significantly associated with larger cup-to-disc ratios at the prevalence examination. Cup-to-disc ratios were not larger in those with high IOP, nor in those who had panretinal photocoagulation.

Adult↗

PubMed1989

Optic disc cupping: four year follow-up from the WESDR.

Change in optic disc cupping was evaluated in a 4-year follow-up of a well defined cohort of people with diabetes mellitus. Cup-to-disc ratios were computed for both vertical and horizontal diameters of each eye at the baseline and 4-year follow-up examinations. Graders were masked as to the identity of participants and to the dates of the photographs. Increases of at least 0.1 between baseline and follow-up were used as clinically significant change in the ratios. None of the following factors at baseline were consistent predictors of such a change: intraocular pressure, age, duration of diabetes, hypertension or severity of diabetic retinopathy. People who developed proliferative retinopathy by the follow-up examination were not more likely to have such an increase in ratio at the follow-up. We conclude that clinically significant increases in cup-to-disc ratio cannot be consistently predicted in people with diabetes from the risk factors evaluated with the grading system used in this study.

Diabetes Complications↗