Showing papers by "Ronald Klein published in 2004"

Causes and prevalence of visual impairment among adults in the United States.

Abstract: Objectives To estimate the cause-specific prevalence and distribution of blindness and low vision in the United States by age, race/ethnicity, and gender, and to estimate the change in these prevalence figures over the next 20 years. Methods Summary prevalence estimates of blindness (both according to the US definition of Results Based on demographics from the 2000 US Census, an estimated 937 000 (0.78%) Americans older than 40 years were blind (US definition). An additional 2.4 million Americans (1.98%) had low vision. The leading cause of blindness among white persons was age-related macular degeneration (54.4% of the cases), while among black persons, cataract and glaucoma accounted for more than 60% of blindness. Cataract was the leading cause of low vision, responsible for approximately 50% of bilateral vision worse than 6/12 (20/40) among white, black, and Hispanic persons. The number of blind persons in the US is projected to increase by 70% to 1.6 million by 2020, with a similar rise projected for low vision. Conclusions Blindness or low vision affects approximately 1 in 28 Americans older than 40 years. The specific causes of visual impairment, and especially blindness, vary greatly by race/ethnicity. The prevalence of visual disabilities will increase markedly during the next 20 years, owing largely to the aging of the US population.

The prevalence of diabetic retinopathy among adults in the United States.

Abstract: Objective: To determine the prevalence of diabetic retinopathy among adults 40 years and older in the United States.Methods: Pooled analysis of data from 8 population-based eye surveys was used to estimate the prevalence, among persons with diabetes mellitus (DM), of retinopathy and of vision-threatening retinopathy-defined as proliferative or severe nonproliferative retinopathy and/or macular edema. Within strata of age, race/ethnicity, and gender, US prevalence rates were estimated by multiplying these values by the prevalence of DM reported in the 1999 National Health Interview Survey and the 2000 US Census population.Results: Among an estimated 10.2 million US adults 40 years and older known to have DM, the estimated crude prevalence rates for retinopathy and vision-threatening retinopathy were 40.3% and 8.2%, respectively. The estimated US general population prevalence rates for retinopathy and vision-threatening retinopathy were 3.4% (4.1 million persons) and 0.75% (899000 persons). Future projections suggest that diabetic retinopathy will increase as a public health problem, both with aging of the US population and increasing age-specific prevalence of DM over time.Conclusion: Approximately 4.1 million US adults 40 years and older have diabetic retinopathy; 1 of every 12 persons with DM in this age group has advanced, vision-threatening retinopathy.

Retinopathy in Diabetes

Abstract: Diabetic retinopathy is the most frequent cause of new cases of blindness among adults aged 20 –74 years. During the first two decades of disease, nearly all patients with type 1 diabetes and 60% of patients with type 2 diabetes have retinopathy. In the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR), 3.6% of younger-onset patients (type 1 diabetes) and 1.6% of olderonset patients (type 2 diabetes) were legally blind. In the younger-onset group, 86% of blindness was attributable to diabetic retinopathy. In the older-onset group, in which other eye diseases were common, one-third of the cases of legal blindness were due to diabetic retinopathy. NATURAL HISTORY OF DIABETIC RETINOPATHY Diabetic retinopathy progresses from mild nonproliferative abnormalities, characterized by increased vascular permeability, to moderate and severe nonproliferative d iabetic r etinopathy (NPDR), characterized by vascular closure, to proliferative diabetic retinopathy (PDR), characterized by the growth of new blood vessels on the retina and posterior surface of the vitreous. Macular edema, characterized by retinal thickening from leaky blood vessels, can develop at all stages of retinopathy. Pregnancy, puberty, blood glucose control, hypertension, and cataract surgery can accelerate these changes. Vision-threatening retinopathy is rare in type 1 diabetic patients in the first 3–5 years of diabetes or before puberty. During the next two decades, nearly all type 1 diabetic patients develop retinopathy. Up to 21% of patients with type 2 diabetes have retinopathy at the time of first diagnosis of diabetes, and most develop some degree of retinopathy over time. Vision loss due to diabetic retinopathy results from several mechanisms. Central vision may be impaired by macular edema or capillary nonperfusion. New blood vessels of PDR and contraction of the accompanying fibrous tissue can distort the retina and lead to tractional retinal detachment, producing severe and often irreversible vision loss. In addition, the new blood vessels may bleed, adding the further complication of preretinal or vitreous hemorrhage. Finally, neovascular glaucoma associated with PDR can be a cause of visual loss.

Retinal Arteriolar Diameter and Risk for Hypertension

Abstract: Researchers have speculated that narrowing of the small arterioles contributes to the pathogenesis of hypertension. In this prospective study, patients who were normotensive at baseline but had nar...

Incidence of dry eye in an older population.

Abstract: Objectives To estimate the 5-year incidence of dry eye and to examine its associationwith risk factors. Methods The population of Beaver Dam, Wis, that was 43 to 84 years of age (n= 5924) was examined in the 1988-1990 (n = 4926), 1993-1995 (n = 3722), and1998-2000 study phases (n = 2962). At the 1993-1995 examination, when dryeye data were first collected, and the 1998-2000 examination, 2783 subjectsparticipated, and 44 were interviewed. Of these, 2802 provided dry eye history.The incidence cohort consisted of 2414 subjects not reporting dry eye in the1993-1995 examination. Risk factor information was ascertained at the 1993-1995examination and included demographics, medical history, cardiovascular diseaserisk factors, medications, and lifestyle factors. Results During the 5-year interval between examinations, a history of dry eyedeveloped in 322 of 2414 subjects, for an incidence of 13.3% (95% confidenceinterval [CI], 12.0%-14.7%). Incidence was significantly associated with age( P P P Conclusions Incidence of dry eye is substantial. However, there are few associatedrisk factors. Some drugs (eg, diuretics and antihistamines) are associatedwith a greater risk, whereas others (angiotensin-converting enzyme inhibitors)are associated with lower risk.

Sunlight and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study.

Abstract: Objective To examine the association of sunlight exposure and indicators of sunsensitivity with the 10-year incidence of age-related maculopathy (ARM). Design Population-based cohort study. Participants We included persons aged 43 to 86 years at the baseline examinationfrom 1988 to 1990, living in Beaver Dam, Wis, of whom 3684 persons underwent5-year follow-up and 2764 underwent 10-year follow-up. Methods Data on sun exposure and indicators of sun sensitivity were obtainedfrom a standardized questionnaire administered at baseline and/or follow-up.We determined ARM status by grading stereoscopic color fundus photographsusing the Wisconsin Age-Related Maculopathy Grading System. Main Outcome Measures Incidence and progression of ARM. Results While controlling for age and sex, we found that participants exposedto the summer sun for more than 5 hours a day during their teens, in their30s, and at the baseline examination were at a higher risk of developing increasedretinal pigment (risk ratio [RR], 3.17; 95% confidence interval [CI], 1.24-8.11;P= .01) and early ARM (RR, 2.14; 95% CI, 0.99-4.61;P= .05) by 10 years than those exposed less than 2 hoursper day during the same periods. In participants reporting the highest summersun exposure levels in their teens and 30s, the use of hats and sunglassesat least half the time during the same periods was associated with a decreasedrisk of developing soft indistinct drusen (RR, 0.55; 95% CI, 0.33-0.90;P= .02) and retinal pigment epithelial depigmentation(RR, 0.51; 95% CI, 0.29-0.91;P= .02). Participantswho experienced more than 10 severe sunburns during their youth were morelikely than those who experienced 1 or no burn to develop drusen with a 250-µmdiameter or larger (RR, 2.52; 95% CI, 1.29-1.71;P=.01) by the 10-year examination. No relationships were found between UV-Bexposure, winter leisure time spent outdoors, skin sun sensitivity, or numberof bad sunburns experienced by the time of the baseline examination and the10-year incidence and progression of ARM or its associated lesions. Conclusions Few significant relationships between environmental exposure to lightand the 10-year incidence and progression of ARM were found in the BeaverDam Eye Study. Consistent with results from the baseline and 5-year follow-upexaminations, significant associations were found between extended exposureto the summer sun and the 10-year incidence of early ARM and increased retinalpigment. A protective effect of hat and sunglasses use by participants whilein their teens and 30s against the 10-year incidence of soft indistinct drusenand retinal pigment epithelial depigmentation was also found, but only inthose who reported the highest amount of sun exposure during the same periods.

Associations between the metabolic syndrome and retinal microvascular signs: the Atherosclerosis Risk In Communities study.

Abstract: PURPOSE. To examine the cross-sectional relationship of the metabolic syndrome (hypertension, hyperglycemia, central obesity, and dyslipidemia) and retinal microvascular abnormalities in middle-aged men and women. METHODS. A population-based, cross-sectional study involving 11,265 persons aged 49 to 73 years who had retinal photography from 1993 through 1995. Photographs were graded for presence of retinal microvascular signs (microaneurysms, retinal hemorrhages, arteriovenous nicking, and focal arteriolar narrowing) according to a standardized protocol. To quantify retinal vessel diameters, photographs were digitized and individual arteriolar and venular diameters were measured and summarized. The metabolic syndrome was defined according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel. RESULTS. After adjustment for age, gender, race, education, cigarette smoking and alcohol consumption, persons with the metabolic syndrome were more likely to have retinopathy (odds ratio [OR] 1.68, 95% confidence interval [CI], 1.45-1.96), arteriovenous nicking (OR 1.30, 95% CI, 1.16-1.45), focal arteriolar narrowing (OR 1.24, 95% CI, 1.10-1.38), generalized retinal arteriolar narrowing (OR 1.23, 95% CI, 1.12-1.35), and generalized retinal venular dilatation (OR 1.30, 95% CI, 1.18-1.48) than persons without the metabolic syndrome. Associations for arteriovenous nicking, focal arteriolar narrowing, generalized arteriolar narrowing, and venular dilatation were noted, even in people without diabetes or hypertension. CONCLUSIONS. These data suggest that the metabolic syndrome is associated with microvascular changes in the retina. This finding reflects, in part, the associations of individual syndrome components with retinal microvascular abnormalities.

Prospective cohort study of retinal vessel diameters and risk of hypertension

Abstract: Objective To examine the relation between diameters of the retinal arterioles and 10 year incidence of hypertension. Design Population based prospective cohort study. Setting Beaver Dam eye study. Participants 2451 normotensive people aged 43 to 84 years. Main outcome measures Diameters of retinal arterioles and venules measured from digitised photographs of the retina taken at baseline. Measurements summarised as the arteriole:venule ratio, with a lower ratio indicating smaller arteriolar diameters. Incident hypertension, defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or use of antihypertensive drugs during follow up. Results 721 participants developed hypertension over a 10 year period. Those with lower arteriole:venule ratio had a higher cumulative incidence of hypertension (incidences of 17.4%, 24.1%, 31.0%, and 45.1%, respectively, for decreasing quarters of distribution of arteriole:venule ratio). After adjustment for age and sex, participants with arteriole:venule ratios in the lowest quarter had a threefold higher risk of hypertension (odds ratio 2.95, 95% confidence interval 2.77 to 3.88) than those with ratios in the highest quarter. This association remained significant after further adjustment for baseline systolic and diastolic blood pressure and other risk factors (1.82, 1.39 to 2.40, for lowest versus highest ratio quarters). Conclusions Narrowed retinal arterioles are associated with long term risk of hypertension, suggesting that structural alterations of the microvasculature may be linked to the development of hypertension.

Cardiovascular disease, mortality, and retinal microvascular characteristics in type 1 diabetes: Wisconsin epidemiologic study of diabetic retinopathy

Abstract: Background Diabetic retinopathy and proteinuria, manifestations of microvascular abnormalities, occur early in the course of diabetes mellitus; in contrast, macrovascular cardiovascular complications usually occur later. Retinal vessel characteristics may be informative about risk of cardiovascular disease in persons with diabetes. We evaluated this in a longitudinal cohort study of persons with type 1 diabetes. Methods The population consisted of persons with type 1 diabetes who were receiving care in 11 counties in Wisconsin. Subjects (n = 996) were examined at baseline (1980-1982), and 4, 10, 14, and 20 years later. Evaluations included medical history and measurements of height, weight, blood pressure, and glycosylated hemoglobin. Fundus photographs were graded for diabetic retinopathy at baseline, and the same photographs were graded later for the diameters of retinal blood vessels. At each examination, a history of cardiovascular disease events since the last examination (and prior to baseline) was obtained. Mortality was monitored yearly. Results The 20-year age-adjusted cumulative incidences were 18.1% for angina, 14.8% for myocardial infarction, and 5.9% for stroke. Severity of diabetic retinopathy was associated with angina and stroke. Arteriovenous ratio was associated with myocardial infarction. Of 273 deaths, 176 involved heart disease. The severity of retinopathy and arteriovenous ratio was associated with heart disease mortality. Nephropathy was more informative about the cardiovascular end points than were the blood vessel characteristics. Conclusions Incidences of cardiovascular disease, including mortality, were common in people with type 1 diabetes during a 20-year interval. Retinal vascular characteristics were associated with these end points, but this association was confounded by nephropathy.

The relation of retinal vessel caliber to the incidence and progression of diabetic retinopathy: XIX: the Wisconsin Epidemiologic Study of Diabetic Retinopathy.

Abstract: greater 4-year progression of retinopathy. Larger venular diameters (RR, 4.28; 95% CI, 1.50-12.19; test of trend, P=.006) but not arteriolar diameters were associated with greater 4-year incidence of proliferative retinopathy. In multivariable analyses, arteriolar and venular calibers were not associated with the 4-year incidence of retinopathy. While adjusting for other factors, arteriolar and venular calibers were not associated with incidence of macular edema at 4 years. There were few associations of arteriolar or venular caliber with the 10- or 14-year incidence or the progression of retinopathy. Conclusions: Larger arteriolar and venular caliber, independent of retinopathy severity level, is related to the progression of retinopathy, and larger venular caliber is associated with the 4-year incidence of proliferative retinopathy. Caliber of retinal vessels is not associated with incident retinopathy. These data suggest a quantitative measure of retinal vascular caliber provides additional information regarding risk for progression of retinopathy.

Retinal microvascular abnormalities and renal dysfunction: The Atherosclerosis Risk in Communities Study

Abstract: Microvascular disease has been linked with renal dysfunction in patients with diabetes. The aim of this study was to examine the association of retinal microvascular abnormalities to renal dysfunction among participants of the Atherosclerosis Risk in Communities Study, a population-based investigation in four U.S. communities. At the third examination (1993 to 1995), retinal photography was performed and the presence of retinal microvascular abnormalities was documented using a standard grading protocol. Renal dysfunction was defined as an increase in serum creatinine of at least 0.4 mg/dl or a death or hospitalization as a result of chronic kidney disease between the second (1990 to 1992) and fourth (1996 to 1998) examinations. Among 10,056 people who were included in the study, 270 (2.7%) developed renal dysfunction. After controlling for age, gender, race, diabetes, BP, and other risk factors, individuals with retinopathy (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.4 to 2.8), microaneurysms (OR, 2.0; 95% CI, 1.3 to 3.1), retinal hemorrhages (OR, 2.6; 95% CI, 1.6 to 4.0), soft exudates (OR, 2.7; 95% CI, 1.6 to 4.8), and arteriovenous nicking (OR, 1.4; 95% CI, 1.0 to 1.9) were more likely to develop renal dysfunction than individuals without these abnormalities. Retinal microvascular abnormalities are associated with renal dysfunction, suggesting that common systemic microvascular processes may underlie the development of microvascular damage in the eye and kidneys.

Retinal Arteriolar Narrowing Is Associated With 5-Year Incident Severe Hypertension. The Blue Mountains Eye Study

Abstract: We assessed whether retinal arteriolar narrowing and structural abnormalities independently predicted 5-year incident severe (grade 2 or 3) hypertension in an older population-based cohort. The Blue Mountains Eye Study baseline (1992 to 1994) examined 3654 residents aged 49 and older in 2 postal code areas, west of Sydney. Of the 2335 participants (75.1% of survivors) who returned at the 5-year examinations, 1319 were normotensive or had mild (grade 1) hypertension at baseline. Baseline retinal photographs were graded for focal retinal vessel wall signs and vessel diameters were measured. Participants were classified as having normal, high-normal blood pressure [BP] (systolic BP 121 to 139 mm Hg and/or diastolic BP 81 to 89 mm Hg), mild hypertension (systolic BP 140 to 159 mm Hg and/or diastolic BP 90 to 99 mm Hg), or severe hypertension if they had a previous diagnosis of hypertension and were receiving antihypertensive medications or had systolic BP > or =160 mm Hg and/or diastolic BP > or =100 mm Hg at examination. Incident severe hypertension was defined in persons who were free of severe hypertension at baseline but classified as having severe hypertension at the 5-year examinations. Of the 1319 baseline subjects at risk, 390 (29.6%) developed severe hypertension. After adjusting for age, sex, body mass index, smoking, glucose, and total cholesterol, generalized retinal arteriolar narrowing at baseline was associated with increased risk of incident severe hypertension (odds ratio 2.6; 95% confidence interval, 1.7 to 3.9) when comparing the narrowest versus widest quintile. This association remained significant after further adjustment for baseline mean arterial BP or BP status. Our findings support the hypothesis that small vessel structural changes may precede the development of severe hypertension.

Dissection of genomewide-scan data in extended families reveals a major locus and oligogenic susceptibility for age-related macular degeneration.

Abstract: To examine the genetic basis of age-related macular degeneration (ARMD), a degenerative disease of the retinal pigment epithelium and neurosensory retina, we conducted a genomewide scan in 34 extended families (297 individuals, 349 sib pairs) ascertained through index cases with neovascular disease or geographic atrophy. Family and medical history was obtained from index cases and family members. Fundus photographs were taken of all participating family members, and these were graded for severity by use of a quantitative scale. Model-free linkage analysis was performed, and tests of heterogeneity and epistasis were conducted. We have evidence of a major locus on chromosome 15q (GATA50C03 multipoint P =1.98×10 −7 ; empirical P ≤1.0×10 −5 ; single-point P =3.6×10 −7 ). This locus was present as a weak linkage signal in our previous genome scan for ARMD, in the Beaver Dam Eye Study sample (D15S659, multipoint P =.047), but is otherwise novel. In this genome scan, we observed a total of 13 regions on 11 chromosomes (1q31, 2p21, 4p16, 5q34, 9p24, 9q31, 10q26, 12q13, 12q23, 15q21, 16p12, 18p11, and 20q13), with a nominal multipoint significance level of P ≤.01 or LOD ⩾1.18. Family-by-family analysis of the data, performed using model-free linkage methods, suggests that there is evidence of heterogeneity in these families. For example, a single family (family 460) individually shows linkage evidence at 8 loci, at the level of P

The prevalence of diabetic retinopathy among adult type 1 diabetic persons in the United States.

Abstract: Objective To estimate the US prevalence of diabetic retinopathy (DR) among personswith type 1 diabetes mellitus (DM). Methods Prevalence data from the New Jersey 725 and Wisconsin EpidemiologicStudy of Diabetic Retinopathy were used to estimate the prevalence of DR byage, gender, and race among persons 18 years and older having type 1 DM diagnosedbefore age 30 years. Severity of DR was determined via masked grading of 7-fieldstereoscopic fundus photographs. Any DR was defined as retinopathy severitylevel of 14 or more; and vision-threatening retinopathy, as retinopathy severitylevel of 50 or more, the presence of clinically significant macular edema,or both. The estimates of the prevalence of DR among persons with type 1 DMwere applied to the estimated number of persons with type 1 DM diagnosed beforeage 30 years in the 2000 US population to obtain prevalence estimates of DRdue to type 1 DM in the general population. Results Among 209 million Americans 18 years and older, an estimated 889 000have type 1 DM diagnosed before age 30 years. Among persons with type 1 DM,the crude prevalences of DR of any level (74.9% vs 82.3% in black and whitepersons, respectively) and of vision-threatening retinopathy (30.0% vs 32.2%,respectively) are high. The prevalence of DR due to type 1 DM diagnosed beforeage 30 years in the general population 18 years and older is estimated at767 000 persons having DR of any level (0.37%), and 376 000 personshaving vision-threatening retinopathy (0.18%). Conclusion Retinopathy due to type 1 DM is an important public health problem inthe United States, affecting 1 per 300 persons 18 years and older, and 1 per600 persons with advanced, vision-threatening retinopathy.

Impact of current and past blood pressure on retinal arteriolar diameter in an older population.

Abstract: Objective To examine the effects of current and past blood pressure on retinal arteriolar diameter in a general older population. Design Cross-sectional and longitudinal studies. Setting Population-based cohort study of older residents from an area west of Sydney, Australia. Participants Two thousand three hundred and thirty-five individuals (n = 2335) (aged > or = 54 years) who attended the 5-year follow-up Blue Mountains Eye Study during 1997-99. Main outcome measures A computer-assisted method measured vessel diameters from digitized right eye retinal photographs. The narrowest quintile of central retinal arteriolar equivalent or arteriole-to-venule ratio (AVR) defined generalized arteriolar narrowing. Blood pressure was measured using a mercury sphygmomanometer. Results After simultaneous adjustment for age, sex, body mass index, smoking and current or past blood pressure, elevated levels of both current and past blood pressure were associated with narrower retinal arterioles [Ptrend = 0.009 and 0.007 for current and past systolic blood pressure (SBP), respectively] and lower AVR [Ptrend = 0.001 and 0.0009 for current and past diastolic blood pressure (DBP), respectively]. Generalized arteriolar narrowing was associated with both current blood pressure [adjusted odds ratio (OR) 2.4, 95% confidence interval (CI) 1.5-3.8 for the highest versus lowest quintile of current DBP] and past blood pressure (adjusted OR 1.7, 95% CI 1.1-2.6, for the highest versus lowest quintile of past DBP). Hypertension duration or control status at baseline had no additional effect on arteriolar diameter after adjusting for current blood pressure. Conclusions Our data document the independent effects of both current and past blood pressure on small vessel calibre in the retina, suggesting that retinal arteriolar narrowing may result from the cumulative effects of long-standing hypertension.

Heritability of risk factors for primary open-angle glaucoma: the Beaver Dam Eye Study.

Abstract: Purpose To investigate the family aggregation and heritability of risk indicators of primary open-angle glaucoma. Methods During the baseline examination of the Beaver Dam Eye Study, standardized measurements of intraocular pressure were performed with a Goldmann applanation tonometer. Stereoscopic photographs of the optic discs were taken of both eyes of each study participant. The eyes were graded for the size of the optic disc and cup according to a standardized protocol, with graders masked to other subject characteristics. Family members who had participated in the examination phase were identified. Results Correlations in sibling pairs (n = 1136), parent-child pairs (n = 514), and cousin pairs (n = 1807) for intraocular pressure were 0.17, 0.18, and 0.12, respectively and were all statistically significant, whereas the spouse pair correlation was not. Correlations for sibling, parent-child, and avuncular pairs were higher for vertical optic disc, vertical optic cup, and vertical cup-to-disc ratio than for intraocular pressure. Heritability estimates were 0.36, 0.55, 0.57, and 0.48 for intraocular pressure, optic cup diameter, optic disc diameter, and cup-to-disc ratio, respectively. Correlations for the optic disc parameters were compatible with the amount of gene sharing in relative pairs of different degrees. Conclusions Risk indicators of open-angle glaucoma correlate highly in families, and the patterns are consistent with the hypothesis of genetic determinants of these factors.

Variation associated with measurement of retinal vessel diameters at different points in the pulse cycle

Abstract: Background/aims: To assess the variability in retinal vessel measurements at different points in the pulse cycle. Methods: A healthy white male aged 19 years had 30 digitised images taken at three distinct points in the pulse cycle over a one hour period. A pulse synchronised ear clip trigger device was used to capture images at the desired point in the pulse cycle. Two trained graders measured the retinal vessel diameter of one large arteriole, one large venule, one small arteriole, and one small venule 10 times in each of these 30 images. Results: Within an image, variability was similar between graders, pulse point, and vessel type. Across images taken at the same point in the pulse period, the change from the minimum to maximum measurement was between 6% and 17% for arterioles and between 2% and 11% for venules. In addition, measurements of small vessels had greater changes than large vessels and no point in the pulse period was more variable than another. Ignoring pulse cycle increased variability across images in the large venule, but not in the other vessel types. Mixed effect models were fit for each of the vessel types to determine the greatest source of variability. Controlling for pulse point and grader, the largest source of variability for all four vessels measured was across images, accounting for more than 50% of the total variability. Conclusion: Measurements of large retinal venules is generally less variable than measurements of other retinal vessels. After controlling for pulse point and grader, the largest source of variation is across images. Understanding the components of variability in measuring retinal vessels is important as these techniques are applied in epidemiological studies.

The impact of diabetic retinopathy: perspectives from patient focus groups

Abstract: Background Diabetic retinopathy (DR) affects 50-85% of people with diabetes and may result in visual impairment or blindness. Objective This exploratory qualitative research was conducted to evaluate the symptom experience of DR, its impact on daily activities and health-related quality of life (HRQL), and the applicability of two vision-specific questionnaires. Methods Four focus groups (n = 15) were conducted with people with DR to explore their symptom experience and the impact on functioning and HRQL. Adults with type I or II diabetes and mild, moderate or severe non-proliferative DR (NPDR) or proliferative DR (PDR) were recruited. Content analysis and descriptive statistics were used to analyse the data. Results Participants described a range of symptoms and impact. Difficulty driving, especially at night, and trouble reading were noted with all levels of severity. Participants with PDR and decreased visual acuity have foregone many other important life aspects such as work, reading and sports. For the severely affected, diabetic care activities (e.g. exercising, reading nutritional labels, preparing insulin injections and glucose testing) were difficult to accomplish. Loss of independence, especially mobility and increased fear of accidents, had a profound impact on social activities. For those patients who had not experienced other complications of diabetes, the threat of vision loss was the most devastating. Conclusion The loss of independence and mobility associated with decreased visual functioning and visual loss were major concerns. Moderate, severe NPDR and PDR associated with visual impairment have a significant impact on HRQL, particularly in the areas of independence, mobility, leisure and self-care activities.

Sunlight and the 10-year incidence of age-related maculopathy the beaver dam eye study

Abstract: OBJECTIVE To examine the association of sunlight exposure and indicators of sun sensitivity with the 10-year incidence of age-related maculopathy (ARM). DESIGN Population-based cohort study. PARTICIPANTS We included persons aged 43 to 86 years at the baseline examination from 1988 to 1990, living in Beaver Dam, Wis, of whom 3684 persons underwent 5-year follow-up and 2764 underwent 10-year follow-up. METHODS Data on sun exposure and indicators of sun sensitivity were obtained from a standardized questionnaire administered at baseline and/or follow-up. We determined ARM status by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. MAIN OUTCOME MEASURES Incidence and progression of ARM. RESULTS While controlling for age and sex, we found that participants exposed to the summer sun for more than 5 hours a day during their teens, in their 30s, and at the baseline examination were at a higher risk of developing increased retinal pigment (risk ratio [RR], 2.99; 95% confidence interval [CI], 1.18-7.60; P =.02) and early ARM (RR, 2.20; 95% CI, 1.02-4.73; P =.04) [corrected] by 10 years than those exposed less than 2 hours per day during the same periods. In participants reporting the highest summer sun exposure levels in their teens and 30s, the use of hats and sunglasses at least half the time during the same periods was associated with a decreased risk of developing soft indistinct drusen (RR, 0.55; 95% CI, 0.33-0.90; P =.02) and retinal pigment epithelial depigmentation (RR, 0.51; 95% CI, 0.29-0.91; P =.02). Participants who experienced more than 10 severe sunburns during their youth were more likely than those who experienced 1 or no burn to develop drusen with a 250-microm diameter or larger (RR, 2.52; 95% CI, 1.29-4.94 [corrected] P =.01) by the 10-year examination. No relationships were found between UV-B exposure, winter leisure time spent outdoors, skin sun sensitivity, or number of bad sunburns experienced by the time of the baseline examination and the 10-year incidence and progression of ARM or its associated lesions. CONCLUSIONS Few significant relationships between environmental exposure to light and the 10-year incidence and progression of ARM were found in the Beaver Dam Eye Study. Consistent with results from the baseline and 5-year follow-up examinations, significant associations were found between extended exposure to the summer sun and the 10-year incidence of early ARM and increased retinal pigment. A protective effect of hat and sunglasses use by participants while in their teens and 30s against the 10-year incidence of soft indistinct drusen and retinal pigment epithelial depigmentation was also found, but only in those who reported the highest amount of sun exposure during the same periods.

Retinal Vessel Diameters and the Incidence of Gross Proteinuria and Renal Insufficiency in People With Type 1 Diabetes

Abstract: Early retinal vessel caliber changes may predict risk of diabetic nephropathy. We examined the association of retinal vessel diameters and the incidence of gross proteinuria and renal insufficiency in a population-based cohort of people with type 1 diabetes (n = 557). Baseline retinal photographs were digitized, and diameters of individual retinal vessels were measured and summarized. Incident cases of gross proteinuria and renal insufficiency were identified over a 16-year period. Larger retinal venular diameter was associated with higher cumulative incidence of gross proteinuria (18.6, 25.4, 37.7, and 50.4%, comparing increasing venular diameter quartiles) and renal insufficiency (10.7, 15.5, 23.2, and 32.8%). After adjusting for age, sex, duration of diabetes, HbA(1c) levels, baseline retinopathy levels, and other factors, larger retinal venular diameter was associated with an increased risk of gross proteinuria (RR 1.53, 95% CI 1.19-1.97, comparing 4th vs. 1st to 3rd quartiles of venular diameter) and renal insufficiency (1.51, 1.05-2.17). Retinal arteriolar diameter was not associated with either gross proteinuria or renal insufficiency. We conclude that in individuals with type 1 diabetes, larger retinal venular diameter is independently associated with the long-term incidence of gross proteinuria and renal insufficiency and may provide additional predictive information regarding risk of nephropathy.

Prevalence and Associations of Epiretinal Membranes in Latinos: The Los Angeles Latino Eye Study

Abstract: PURPOSE. To determine age- and gender-specific prevalence and associations of epiretinal membranes (ERMs) in adult Latinos. METHODS. The Los Angeles Latino Eye Study (LALES) is a population-based study of eye disease among Latinos aged 40 or more years. Complete ophthalmic examinations included stereoscopic fundus photography. Masked photographic grading was used to identify and classify ERMs as cellophane macular reflex (CMR) without retinal folds or preretinal macular fibrosis (PMF) with folds. RESULTS. Of the 6142 persons examined at the clinic, 5982 (97%) had gradable retinal photographs. The mean age of the participants was 54.7 ± 10.7 years; 58% were women. ERMs were present in 18.5% (95% confidence interval [CI]: 17.5%-19.5%) of the participants. Of the participants with ERMs, 19.9% had bilateral ERMs. The prevalence of ERMs increased from 10.1% in persons 40 to 49 years of age to 35.7% in those aged 70 to 79 years and was 22.5% in persons aged 80 years or more. The prevalence was similar in men and women. CMR was present in 16.3% (95% CI: 15.3%-17.2%) and PMF in 2.2% (95% CI: 1.9%-2.6%). Retinal folds involved the fovea in 11% of PMF cases. On average, eyes with central PMF had poorer visual acuity than did eyes without (P < 0.0002). Epiretinal membranes (ERMs) were present in 71% of eyes with macular holes. ERMs were also more common in individuals who had undergone cataract surgery (39.9%), those with proliferative diabetic retinopathy (25.7%), and those with any retinal disease (27.5%). CONCLUSIONS. ERMs occur frequently in Latinos, often bilaterally. The associations of ERMs with proliferative retinopathy, retinal lesions, macular holes, and cataract surgery were confirmed. Central PMF is associated with reduced visual acuity.