Macular Degeneration: Liao D

Liao D, Mo J, Duan Y, Klein R, Scott IU, Huang KA, Zhou H. · Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, USA. · Open Ophthalmol J. · Pubmed #19516892 links to  free full text

Abstract: OBJECTIVE: To investigate whether age-related macular degeneration (AMD) is associated with the development of ischemic and hemorrhagic stroke among elderly Americans. DESIGN: Population-based cohort study. PARTICIPANTS: The five percent random sample of 2000-2003 Medicare enrollees was obtained. The cohort (n=1,519,086) consisted of enrollees who were aged 65 or older at the first two-year (January 1, 2000 to December 31, 2001). METHODS: Baseline demographic variables and chronic conditions (AMD and type, history of myocardial infarction (MI), stroke, hypertension, and diabetes) were defined based on the occurrence of relevant ICD-9 codes in relevant diagnosis fields of the baseline Medicare Data. We excluded 215,900 persons who had a diagnosis of MI or stroke during baseline period to form a cohort of 1,303,186 individuals who were free of major cardio-cerebral vascular disease (CVD) at baseline. MAIN OUTCOME MEASURES: In two years of follow-up (January 1, 2002 to December 31, 2003), a total of 89,501 incident stroke cases were identified, including 80,018 ischemic, 7048 hemorrhagic, and 2,435 stroke cases of both types. RESULTS: Baseline mean age was 75 years (Standard Divination=7.7), with 60% women and 88% whites. The prevalence of AMD was 10.6%, with 19.7% being neovascular AMD and 80.3% being non-neovascular AMD. Baseline age, gender, race, hypertension, and diabetes adjusted 2-year incident odds ratios and 95% confidence internal of stroke associated with AMD were 1.31 (1.26, 1.36) for neovascular AMD, 1.18 (1.15, 1.21) for non-neovascular AMD, and 1.21 (1.18, 1.23) for either neovascular or non-neovascular AMD. CONCLUSION: The findings are suggestive of an association between AMD, especially neovascular AMD, and incident stroke, independent of demographic factors and co-morbidity. These findings, if confirmed by other studies that control for smoking and other lifestyle covariables not measured in this study, suggest the possibility of shared common antecedents between stroke and AMD.

Duan Y, Mo J, Klein R, Scott IU, Lin HM, Caulfield J, Patel M, Liao D. · Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA. · Ophthalmology. · Pubmed #17187863 No free full text.

Abstract: OBJECTIVE: To investigate whether age-related macular degeneration (AMD) is associated with the development of myocardial infarction (MI) among elderly Americans. DESIGN: Population-based cross-sectional and cohort study. PARTICIPANTS: Five percent random sample of 2000 to 2003 Medicare enrollees. METHODS: The cross-sectional study included the first 2-year (2000 and 2001) enrollees who were aged > or =65 years (n = 1,519,086). The cohort study included only baseline MI-free enrollees (n = 1445677). MAIN OUTCOME MEASURES: Chronic conditions (AMD and type, history of MI, hypertension, and diabetes) were defined based on any occurrence of relevant International Classification of Diseases 9 codes in relevant diagnosis fields of the baseline Medicare claim files. A total of 56611 incident MI cases were identified from the follow-up data (2002 and 2003). RESULTS: Baseline mean age was 76 years, with 60% women and 88% whites. The prevalence of neovascular AMD was 2.2% (2.3% in women vs. 1.7% in men and 2.3% in whites vs. 1.2% in blacks; P<0.01 for both gender and race differences). The prevalence of nonneovascular AMD was 8.8% (9.9% in women vs. 7.3% in men and 9.5% in whites vs. 4.3% in blacks; P<0.01 for both gender and race differences). Baseline age-, gender-, and race-adjusted prevalences of hypertension, diabetes, and history of MI were 75%, 33%, and 5.00%, respectively, in the neovascular AMD group. In contrast, they were 73%, 27%, and 4.68% in the nonneovascular AMD group, and 65%, 25%, and 4.54% in the non-AMD group (P<0.01 for comparing the prevalence in neovascular and nonneovascular AMD vs. non-AMD groups). Prospectively, baseline age-, gender-, race-, hypertension-, and diabetes-adjusted 2-year incident odds ratios and 95% confidence intervals of MI associated with AMD are 1.19 (1.16-1.22) for all persons with AMD, 1.26 (1.20-1.33) for neovascular AMD, and 1.18 (1.14-1.21) for nonneovascular AMD. CONCLUSIONS: AMD is associated with older age, female gender, being white, and having a history of MI, hypertension, and diabetes. Furthermore, presence of AMD, especially neovascular AMD, is prospectively associated with a higher risk of incident MI. These findings, if confirmed by other studies that control for smoking and other lifestyle covariables, suggest the possibility of shared common antecedents between MI and AMD.

Cheung N, Liao D, Islam FM, Klein R, Wang JJ, Wong TY. · Centre for Eye Research Australia, University of Melbourne, 32 Gisborne Street, Melbourne, Victoria 3002, Australia. · Br J Ophthalmol. · Pubmed #17035267 No free full text.

Abstract: BACKGROUND/ PURPOSE: Atherosclerosis and vascular stiffness have been implicated in the pathogenesis of age-related macular degeneration (AMD). The association of carotid artery stiffness, a measure of arterial elasticity reflecting early atherosclerosis, with early AMD, was examined in this study. METHODS: A population-based, cross-sectional study of 9954 middle-aged people (age range 51-72 years). The presence of AMD signs was determined from fundus photographs according to the Wisconsin grading protocol. Carotid arterial stiffness was measured from high-resolution ultrasonic echo tracking of the left common carotid artery, and was defined as an adjusted arterial diameter change (AADCmu). A smaller AADC reflects greater carotid artery stiffness. The associations of pulse pressure and carotid artery intima-media thickness (IMT) with early AMD signs were also analysed. RESULTS: In the study population, 454 (4.6%) had early AMD. The mean (SD) AADC was 403 (127) mu. After adjusting for age, sex, race/centre, education, cigarette smoking, fasting glucose, lipid profile and inflammatory markers, a smaller AADC was found to be not associated with early AMD (odds ratio 0.94; 95% confidence interval, 0.71 to 1.25) or its component lesions. Other measures of arterial stiffness (pulse pressure) and atherosclerosis (carotid IMT) were also not associated with early AMD. CONCLUSIONS: Carotid artery stiffness was not associated with signs of early AMD in this middle-aged population. These data provide no evidence of a link between age-related elastoid changes and early atherosclerotic processes in the carotid arteries and early AMD.