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Tien Y Wong

Publications and source records attributed to Tien Y Wong.

At least 19 recordsLinked to original sources
PubMed2007

Apolipoprotein e gene and age-related maculopathy in older individuals: the cardiovascular health study.

OBJECTIVE: To examine the association between the apolipoprotein E (APOE) gene and age-related maculopathy (ARM) in an older population. METHODS: Two thousand one hundred seventy persons 65 years and older sampled from 4 US communities had ARM signs assessed from retinal photographs using a modified Wisconsin Age-Related Maculopathy Grading System. DNA extracted from blood samples was analyzed for common APOE alleles. RESULTS: After controlling for age, sex, cigarette smoking, and other factors, white participants carrying the epsilon2 allele had an increased risk of late ARM (odds ratio, 2.53 [95% confidence interval, 1.08-5.90]) while carriers of the epsilon4 allele had a lower risk of late ARM (odds ratio, 0.69 [95% confidence interval, 0.19-2.50]). There were too few late ARM cases in African American individuals for analysis. CONCLUSION: APOE polymorphism is associated with late ARM in older white persons 65 years and older. Consistent with previous studies, the APOE epsilon2 allele is associated with a significant increased risk of late ARM development, whereas the epsilon4 allele may confer some protection.

Black or African American↗
PubMed2006

Is diabetic retinopathy an independent risk factor for ischemic stroke?

BACKGROUND AND PURPOSE: The relationship between diabetic retinopathy and ischemic stroke is uncertain and examined in this study. METHODS: A population-based, prospective cohort study of 1617 middle-aged persons with diabetes. Diabetic retinopathy signs were ascertained from retinal photographs, and incident ischemic stroke events were prospectively identified and validated. RESULTS: Over an average follow-up of 7.8 years, there were 75 ischemic stroke events. After adjustment for age, gender, race, center, 6-year mean arterial blood pressure, anti-hypertensive treatment use, fasting glucose, insulin treatment, duration of diabetes, high-density lipoprotein and low-density lipoprotein cholesterol levels and cigarette smoking status, diabetic retinopathy was associated with an increased risk of ischemic stroke (hazard rate ratio, 2.34; 95% CI, 1.13 to 4.86). CONCLUSIONS: Diabetic retinopathy predicts incident ischemic stroke in people with diabetes, independent of other risk factors.

Brain Ischemia↗
PubMed2006

Is early age-related macular degeneration associated with cerebral MRI changes? The Atherosclerosis Risk in Communities study.

PURPOSE: To examine the relation of early age-related macular degeneration (AMD) with cerebral magnetic resonance imaging (MRI) changes. DESIGN: Population-based, cross-sectional study. METHODS: A sample of 1,684 persons ages 51 to 72 years with no history of stroke had cerebral MRI and retinal photography. MRI scans were graded for severity of white matter lesions (WML), sulcal widening (SW), and ventricular enlargement (VE). AMD was graded from retinal photographs. RESULTS: After adjustment for age, gender, race, or center, early AMD (5.0% of participants) was not significantly associated with WML (odds ratio [OR] 1.0, 95% confidence intervals [CI], 0.6 to 1.6), SW (OR 0.6, 95% CI, 0.4 to 1.2), or VE (OR 1.0, 95% CI, 0.6 to 1.8). CONCLUSIONS: These data showed no statistically significant association of early AMD with cerebral MRI changes, but the study was limited by a small number of cases with wide CIs. Further studies may clarify these associations.

Aged↗
PubMed2006

Retinal vascular manifestations of metabolic disorders.

Metabolic diseases have profound effects on the structure and function of the retinal circulation. The recent development of retinal photography and digital imaging has enabled more precise documentation of diabetic retinopathy, as well as other retinal microvascular changes, such as retinal arteriolar narrowing, venular dilation and isolated retinopathy signs in nondiabetic individuals. These retinal microvascular signs have been shown to be associated with long-term risks of type 2 diabetes and hypertension, components of the metabolic syndrome (e.g. obesity, dyslipidemia), and a range of macro- and micro-vascular conditions (e.g. stroke, cardiovascular mortality). There is evidence that endothelial dysfunction and inflammation might be possible mechanisms involved in the development of various retinal microvascular changes in patients with diabetes, hypertension and other metabolic disorders. Further understanding of how these processes influence the retinal vasculature might help to elucidate the diverse vascular manifestations of metabolic diseases.

Animals↗
PubMed2006

Retinal vascular caliber in persons with type 2 diabetes: the Wisconsin Epidemiological Study of Diabetic Retinopathy: XX.

PURPOSE: To describe retinal vascular caliber and correlates in people with type 2 diabetes. DESIGN: Population-based study. PARTICIPANTS: Thirteen hundred seventy persons diagnosed to have diabetes at or after 30 years of age in an 11-county area in south central Wisconsin from 1980 to 1982. METHODS: Retinal photographs of 7 standard fields were taken; light box grading was done to determine retinopathy severity. Computer-assisted grading was done from a digitized image of field 1 to determine the central retinal arteriolar equivalent (CRAE; arteriolar caliber) and central retinal venular equivalent (CRVE; venular caliber). MAIN OUTCOME MEASURES: Retinal arteriolar and venular calibers. RESULTS: In multivariable analyses in persons with panretinal photocoagulation excluded, while controlling for refractive error, CRAE was associated independently with age (per 10 years, beta = -2.0 microm), mean arterial blood pressure (BP) (per 10 mmHg, beta = -2.2 microm), smoking status (current vs. never smoked, beta = 5.6 microm), and intraocular pressure (IOP) (per 1 mmHg, beta = 0.2 microm). The CRVE was associated independently with age (per 10 years, beta = -2.5 microm), mean arterial BP (per 10 mmHg, beta = -2.1 microm), smoking status (current vs. never smoked, beta = 11.6 microm), pack-years smoked (per 10 pack-years, beta = 1.0 microm), body mass index (per kg/m2, beta = 0.3 mm), pulse rate (per 10 beats/minute, beta = 1.5 microm), retinopathy severity (per 1 level, beta = 1.05 microm), and IOP (per 10 mmHg, beta = -0.5 microm). Smaller CRAEs and CRVEs were found in eyes with panretinal photocoagulation treatment than in eyes without such treatment. CONCLUSIONS: In persons with type 2 diabetes, variations in retinal vascular caliber are related to various systemic and ocular factors. Understanding these relationships may provide further insights into early retinal vascular changes in diabetes.

Adult↗
PubMed2006

Retinal vascular caliber and risk of retinopathy in young patients with type 1 diabetes.

OBJECTIVE: To examine the relationship between retinal vascular caliber and incident retinopathy in children and adolescents with type 1 diabetes mellitus. DESIGN: Hospital-based case-control study with prospective outcomes. PARTICIPANTS: Cases and controls were selected from a cohort of children and adolescents 12 to 20 years old with type 1 diabetes followed up at a tertiary diabetes clinic. Cases were patients who developed incident diabetic retinopathy (n = 166) after at least 1 year of follow-up (> or =2 clinic visits), and controls were patients who had not developed retinopathy (n = 165) after > or =2 years of follow-up (> or =3 clinic visits). Baseline retinal photographs of cases and controls were digitized, and retinal vascular calibers were measured using a computer-assisted program by a grader masked to case-control status. These measurements were combined into summary indices reflecting the average arteriolar and venular calibers. MAIN OUTCOME MEASURE: Development of diabetic retinopathy. RESULTS: Incident retinopathy cases had retinal arteriolar calibers (mean +/- standard deviation [SD], 206.5+/-18.4 microm) significantly larger than those of controls (200.2+/-16.5 microm) (P = 0.004) but similar retinal venular calibers (329.1+/-14.7 microm in cases vs. 326.4+/-15.1 microm in controls, P = 0.312). After adjusting for age, gender, diabetes duration, glycated hemoglobin levels, blood pressure, body mass index, and pubertal stage, larger arteriolar caliber was predictive of risk of diabetic retinopathy (odds ratio, 1.44 per SD increase in arteriolar caliber; 95% confidence interval, 1.11-1.86). CONCLUSION: Larger retinal arteriolar caliber predicts incident retinopathy in children and adolescents with type 1 diabetes, independent of conventional risk factors for retinopathy. Measurement of retinal vascular caliber may provide prognostic information regarding the subsequent risk of diabetic retinopathy.

Adolescent↗
PubMed2006

Abnormalities of retinal microvascular structure and risk of mortality from ischemic heart disease and stroke.

Abnormalities of the retinal microcirculation are found in hypertension and diabetes and predict cardiovascular mortality. This study examined the relationship between abnormalities of the retinal microvasculature and death from ischemic heart disease (IHD) and stroke. A population-based, nested case-control study was undertaken within the Beaver Dam Eye Study. Subjects (43 to 74 years) who died of IHD (n=126) or stroke (n=28) over a 10-year period were age and gender matched with controls subjects (n=528; case:control matching, approximately 1:4). Retinal photographs of cases and controls were digitized and analyzed using a computer-based technique. Increased risk of IHD death was associated with a suboptimal relationship of arteriolar diameters at bifurcation (P=0.02 unadjusted) and decreased retinal arteriolar tortuosity (P=0.011 unadjusted). These associations remained significant after adjustment for age, sex, past history of cardiovascular disease, and other known cardiovascular risk factors. Increased arteriolar length:diameter ratio, a measure of generalized arteriolar narrowing, was associated with increased stroke mortality (P=0.02 unadjusted). This association was independent of age and gender but was attenuated by adjustment for systolic blood pressure (P=0.15). Other quantitative measures of the retinal microvascular network (eg, venular tortuosity and arteriolar and venular bifurcation angle) were not associated with death from IHD or stroke. Retinal microvascular abnormalities are predictive of death from IHD and stroke. A detailed assessment of the retinal microvascular network from digitized photographs may be useful in the noninvasive assessment of target organ damage and cardiovascular risk.

Aged↗
PubMed2006

Are inflammatory factors related to retinal vessel caliber? The Beaver Dam Eye Study.

OBJECTIVE: To examine the relationship of systemic markers of inflammation, endothelial dysfunction, and serum folate level to retinal vessel diameter. METHODS: Cross-sectional analyses were completed for data from a random sample of 396 persons aged 50 to 86 years who underwent a baseline examination from 1988 to 1990. Standardized protocols for blood collection and measurement of markers were used. Diameters of arterioles and venules were measured from digitized photographs. Standard univariate and multivariate analyses were performed. RESULTS: While controlling for age, smoking status, diabetes status, serum high-density lipoprotein cholesterol, and hematocrit, wider retinal venular diameters were associated with higher serum high-sensitivity C-reactive protein, interleukin 6, and amyloid A levels. While controlling for age, systolic and diastolic blood pressure, smoking, serum high-density lipoprotein cholesterol level, and gout, smaller arteriolar diameters were associated with higher serum amyloid A and lower serum albumin and folate levels but not high-sensitivity C-reactive protein or interleukin 6 levels. Levels of serum soluble intercellular adhesion molecule-1 and serum soluble E-selectin, markers of endothelial dysfunction, were not associated with retinal arteriolar or venular diameters. CONCLUSIONS: These data show an association of inflammatory markers with larger retinal venular diameter, suggesting that retinal venular caliber may be a marker of systemic inflammation.

Aged↗
PubMed2006

Hypermetropia, axial length, and hypertension: the Tanjong Pagar survey.

PURPOSE: To examine the relationship among hypermetropia, axial length, and hypertension in a Chinese population. DESIGN: Population-based cross-sectional study. METHODS: This study included 1213 Chinese individuals aged 40 to 81 years. Hypertension was defined as systolic blood pressure > or =140 mm Hg, diastolic blood pressure > or =90 mm Hg, or self-report history of antihypertension treatment. Refraction was determined with an autorefractor and refined subjectively. A-mode ultrasound scanning was used to measure axial length. RESULTS: The crude odds ratio of hypertension was 2.5 (95% CI, 1.4-4.6) for moderate hypermetropia (> or =+2.00 spheric equivalent diopters) vs high myopia (< or =-6.00 diopters), and 1.4 (95% CI, 0.9-2.1) for highest vs lowest axial length quintile. These associations were no longer significant after adjustment for age, gender, education, housing type, and income. CONCLUSIONS: These data provide no evidence that hypermetropia or shorter axial length is associated independently with hypertension in Chinese individuals.

Adult↗
PubMed2006

Apolipoprotein E gene polymorphisms are not associated with diabetic retinopathy: the atherosclerosis risk in communities study.

PURPOSE: Polymorphism of the apolipoprotein E (APOE) gene has been associated with dyslipidemia and cardiovascular disease. This study examines the association of APOE polymorphisms and diabetic retinopathy. DESIGN: Population-based cross-sectional study. METHODS: We studied 1,398 people aged 49 to 73 years with diabetes selected from four United States communities. We performed retinal photography on one randomly selected eye and graded for the presence and severity of diabetic retinopathy using a modification of the Early Treatment Diabetic Retinopathy Study scale. We performed genotyping of common polymorphic APOE alleles using polymerase chain reaction on genomic DNA from venous blood leukocytes. RESULTS: The prevalence of diabetic retinopathy and hard exudates was 15.0% and 5.3% in Caucasians (n = 935), and 24.6% and 9.7% in African-Americans (n = 463), with type 2 diabetes. APOE gene polymorphisms were not associated with diabetic retinopathy in either Caucasians or African-Americans. In African-Americans, the 2/4 genotype (n = 6) was associated with increased prevalence of hard exudates (odds ratio [OR] 4.10, 95% confidence interval [CI] 1.30 to 12.90), as was the 2/3 genotype (n = 9, OR 2.64, 95% CI 1.01 to 6.95). No association between APOE genotypes and hard exudates was found in Caucasians. CONCLUSIONS: These data suggest that APOE gene polymorphisms are not associated with diabetic retinopathy in either Caucasians or African-Americans with type 2 diabetes.

Aged↗
PubMed2006

Homocysteine and retinal emboli: the Blue Mountains Eye Study.

PURPOSE: To examine the association between serum homocysteine and retinal emboli in a general older population. DESIGN: Cross-sectional population-based study. METHODS: Homocysteine level was determined from fasting venous blood collection at the second Blue Mountains Eye Study (BMES) (n = 3509, age > or =49 years, 1997 to 2000). Retinal emboli were graded from retinal photographs. Using logistic regression, we analyzed associations between serum homocysteine and retinal emboli adjusting for age, gender, hypertension, body mass index, and lipid levels. RESULTS: After multivariable adjustment, serum homocysteine was associated with presence of retinal emboli (odds ratio (OR) 1.2; 95% confidence interval (CI), 1.0 to 1.6 per standard deviation [4.8 micromol/l] increase in serum homocysteine). CONCLUSION: Elevated serum homocysteine is weakly associated with increased odds of retinal emboli in this older population-based study.

Aged↗
PubMed2006

Retinal vessel diameters and obesity: a population-based study in older persons.

OBJECTIVE: Obesity is linked with large vessel atherosclerosis and diabetes. Its association with microvascular changes is less clear. We investigated the associations among retinal vessel diameters, vessel wall signs, and BMI in an older population. RESEARCH METHODS AND PROCEDURES: Retinal photographs were taken on 3654 persons aged 49+ years at baseline of the Blue Mountains Eye Study in Australia. Arteriolar and venular diameters were measured from digitized retinal photographs of the right eyes. BMI was calculated as weight (kilograms)/height (meters2). Incident obesity was defined in persons with BMI < or = 30 at baseline but > 30 after 5 years. A significant weight gain was defined as an increase in BMI of 2+ SDs (4 or more units) over the 5-year period. RESULTS: At baseline, mean BMI was 26.1 (+/-4.6) in this population. At 5-year examinations, 177 (10.0% of 1773 at risk) developed incident obesity, and 136 (6.4% of 2143 at risk) had significant weight gain. After adjusting for age, sex, smoking, triglyceride levels, and mean arterial blood pressure, persons with wider retinal venular diameters had a higher risk of incident obesity (odds ratio, 1.8; 95% confidence interval, 1.0 to 3.1, comparing the highest with lowest venular diameter quintiles) and significant weight gain (odds ratio, 1.7; 95% confidence interval, 0.9 to 3.2). These associations were attenuated with further adjustment for baseline BMI. Arteriolar diameter was unrelated with baseline or change in BMI. DISCUSSION: Wider retinal venular diameter is associated with risk of obesity, independent of hypertension, diabetes, lipids, and cigarette smoking. These data may support a role for impaired microvascular function in the course of weight gain.

Aged↗
PubMed2006

Fred Hollows lecture: hypertensive retinopathy - a journey from fundoscopy to digital imaging.

Hypertensive retinopathy refers to a spectrum of retinal microvascular signs that develop in response to elevated blood pressure. These signs are broadly divided into localized signs (focal retinal arteriolar narrowing, arteriovenous nicking, retinal haemorrhages, cotton wool spots, hard exudates and microaneurysms) and diffuse signs (generalized retinal arteriolar narrowing, arterial wall opacification and optic disc oedema). Although their association with systemic morbidity was recognized more than a century ago, the prognostic significance of hypertensive retinopathy has not received much attention. In large part, this is because clinical assessment of hypertensive retinopathy signs with the direct fundoscopy has proven imprecise. Data from large population-based studies in the past decade, using retinal photographic methods to define hypertensive retinopathy signs, have provided new insights into the epidemiology, systemic associations and clinical significance of hypertensive retinopathy. These studies show that hypertensive retinopathy signs are common (up to 14% of adults aged 40 years and older, even in those without clinical diabetes or hypertension) and are strongly associated with blood pressure. Various retinopathy signs predict the risk of stroke, congestive heart failure and cardiovascular mortality, independent of blood pressure and other risk factors. These data suggest that patients with hypertensive retinopathy signs may benefit from a careful cardiovascular evaluation, and appropriate risk reduction therapy if indicated. Future advances in digital retinal imaging technology will allow researchers and clinicians to better chart and monitor the vascular effects of hypertension.

Humans↗
PubMed2005

Retinal microvascular abnormalities and MRI-defined subclinical cerebral infarction: the Atherosclerosis Risk in Communities Study.

BACKGROUND AND PURPOSE: Retinal microvascular abnormalities reflect cumulative small vessel damage from elevated blood pressure and may reflect subclinical cerebral microvascular changes. We examined their associations with MRI-defined cerebral infarcts. METHODS: Population-based, cross-sectional study of 1684 persons 55 to 74 years of age without a history of clinical stroke, sampled from 2 US southeastern communities. Retinal photographs were obtained and graded for presence of retinal microvascular abnormalities, including arteriovenous nicking, focal arteriolar narrowing, retinal hemorrhages, soft exudates and microaneurysms. Photographs were also digitized, and retinal vessel diameters were measured and summarized as the arteriole-to-venule ratio (AVR). Cerebral MRI scans were graded for presence of cerebral infarct, defined as a lesion > or =3 mm diameter in a vascular distribution with typical imaging characteristics. RESULTS: There were a total of 183 MRI cerebral infarcts. After adjustment for age, gender, race, 6-year mean arterial blood pressure, diabetes, and other stroke risk factors, cerebral infarcts were associated with retinal microvascular abnormalities, with odds ratios 1.90 (95% CI, 1.25 to 2.88) for arteriovenous nicking, 1.89 (95% CI, 1.22 to 2.92) for focal arteriolar narrowing, 2.95 (95% CI, 1.30 to 6.71) for blot hemorrhages, 2.08 (95% CI, 0.69, 6.31) for soft exudates, 3.17 (95% CI, 1.05 to 9.64) for microaneurysms, and 1.74 (95% CI, 0.95 to 3.21) for smallest compared with largest AVR. In stratified analyses, these associations were only present in persons with hypertension. CONCLUSIONS: Retinal microvascular abnormalities are associated with MRI-defined subclinical cerebral infarcts independent of stroke risk factors. These data suggest that retinal photography may be useful for studying subclinical cerebrovascular disease in population-based studies.

Aged↗
PubMed2005

Retinopathy and risk of congestive heart failure.

CONTEXT: Congestive heart failure (CHF) affects a substantial proportion of adults including those without preexisting coronary heart disease. The pathogenesis of CHF is uncertain, but microvascular disease has been hypothesized as a possible factor. OBJECTIVE: To determine the relationship of retinopathy, a marker of systemic microvascular disease, to risk of CHF. DESIGN, SETTING, AND PARTICIPANTS: Population-based, prospective 7-year cohort study in 4 US communities using the Atherosclerosis Risk in Communities Study database. Participants (n = 11,612, aged 49 to 73 years) had retinal photographs taken between 1993 and 1995. The photographs were graded according to a standardized protocol for the presence of retinopathy (eg, microaneurysms, retinal hemorrhages, soft exudates), arteriovenous nicking, focal arteriolar narrowing, and generalized arteriolar narrowing. MAIN OUTCOME MEASURES: Association between retinopathy and incident CHF, identified from hospitalization and death records. RESULTS: The 7-year cumulative incidence of CHF was 5.4% (492 events). Participants with retinopathy had a higher incidence of CHF compared with those without retinopathy (15.1% vs 4.8%, P<.001). After controlling for age, sex, race, preexisting coronary heart disease, mean arterial blood pressure, diabetes, glucose level, cholesterol level, smoking, body mass index, and study site, the presence of retinopathy was associated with a 2-fold higher risk of CHF (relative risk, 1.96; 95% confidence interval, 1.51-2.54). Among participants without preexisting coronary heart disease, diabetes, or hypertension, retinopathy was associated with a 3-fold higher risk of CHF (relative risk, 2.98; 95% confidence interval, 1.50-5.92). CONCLUSIONS: Retinopathy is an independent predictor of CHF, even in persons without preexisting coronary heart disease, diabetes, or hypertension. This suggests that microvascular disease may play an important role in the development of heart failure in the general population. Some asymptomatic persons with retinopathy on an ophthalmologic examination may benefit from further assessment of CHF risk.

Adult↗
PubMed2005

Homocysteine and retinal vein occlusion: a population-based study.

PURPOSE: To report population data on the association between homocysteinemia and retinal vein occlusion (RVO). DESIGN: Cross-sectional, population-based study. METHODS: Total serum homocysteine (tHcy) was estimated in subjects attending the second Blue Mountains Eye Study (BMES) (n = 3509, aged >49 years). Its association with RVO (graded from retinal photographs) was examined. RESULTS: Homocysteine was more strongly associated with RVO in younger than older participants. In those aged <70 years, homocysteine levels >15 micromol/l were associated with increased odds of RVO, odds ratio (OR) 3.76; 95% confidence interval (CI) 1.06-13.40, in multivariable-adjusted analyses. Each 1 micromol/l increase in homocysteine was associated with a 7% increased odds of RVO, OR 1.07; CI 0.99-1.17 (P = .08). CONCLUSION: This population-based study showed that elevated serum homocysteine is associated with the presence of RVO, independent of other risk factors.

Aged↗