Astrid Fletcher

Astrid Fletcher
London School of Hygiene and Tropical Medicine | LSHTM

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416
Publications
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50,775
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Publications

Publications (416)
Article
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Nuclear cataract is the most common type of age-related cataract and a leading cause of blindness worldwide. Age-related nuclear cataract is heritable (h² = 0.48), but little is known about specific genetic factors underlying this condition. Here we report findings from the largest to date multi-ethnic meta-analysis of genome-wide association studi...
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Objective Although there have been many population-based studies of age-related macular degeneration (AMD) only limited information is available in Asia on the epidemiology of geographic atrophy (GA). We aimed to determine the prevalence and patterns of GA through an analysis of multiple studies conducted within the Asian Eye Epidemiology Consortiu...
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Importance Studies in high-income countries provide limited evidence from randomized clinical trials on the benefits of teleretinal screening to identify diabetic retinopathy (DR). Objective To evaluate the effectiveness of teleretinal-screening hospital referral (TR) compared with universal hospital referral (UR) in people with diabetes. Design,...
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We aimed to describe serum 25-hydroxyvitamin D (25OHD) concentrations in older Europeans and to investigate associations between 25OHD and lifestyle factors, including dietary intake and supplement use. Men and women aged ≥ 65 years were recruited from seven centres across north to south Europe. Serum 25OHD2 and 25OHD3 concentrations were measured...
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Background Cataract is a major health burden in many countries and a significant problem in India. While observational studies show lower cataract risk with increasing dietary or plasma vitamin C, randomised controlled trials of supplements have been negative. Genetic variants in vitamin C transporter proteins ( SLC23A1 ), especially rs33972313, ma...
Data
Table S1. Distribution of presenting and best corrected visual acuity in eyes of people with myopia (SE ≤ −0.75 D) categorized by the presence or absence of advanced cataract in the corresponding eye.
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Purpose To investigate prevalence and risk factors for myopia, hyperopia and astigmatism in southern India. Methods Randomly sampled villages were enumerated to identify people aged ≥40 years. Participants were interviewed for socioeconomic and lifestyle factors and attended a hospital‐based ophthalmic examination including visual acuity measureme...
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Background/Aims There are limited data from India on genetic variants influencing late age-related macular degeneration (AMD). We have previously reported associations from a population-based study in India (the India age-related eye disease study (INDEYE)) of early AMD and single nucleotide polymorphisms (SNPs) in ARMS2/HTRA1 and no association wi...
Article
Importance C-reactive protein (CRP) is a circulating inflammatory marker associated with late age-related macular degeneration (AMD). It remains uncertain whether the association between CRP concentrations and AMD is causal. Objective To assess whether CRP (OMIM 123260) single-nucleotide polymorphisms that influence circulating CRP concentrations...
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Purpose: Age-related macular degeneration (AMD) is a frequent, complex disorder in elderly of European ancestry. Risk profiles and treatment options have changed considerably over the years, which may have affected disease prevalence and outcome. We determined the prevalence of early and late AMD in Europe from 1990 to 2013 using the European Eye...
Article
Importance: Myopia is becoming increasingly common globally and is associated with potentially sight-threatening complications. Spending time outdoors is protective, but the mechanism underlying this association is poorly understood. Objective: To examine the association of myopia with ultraviolet B radiation (UVB; directly associated with time...
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Purpose: To examine associations between adherence to a Mediterranean diet and prevalence of age-related macular degeneration (AMD) in countries ranging from Southern to Northern Europe. Design: Cross-sectional, population-based epidemiologic study. Participants: Of 5060 randomly sampled people aged 65 years or older from 7 study centers acros...
Article
This is a protocol for a Cochrane Review (Overview). The objectives are as follows: To provide an overview of the benefits and harms of interventions for neovascular AMD as measured 12 months after the start of treatment. To consider the longer term effects of these interventions (after 24 months). To identify gaps in the evidence.
Article
Purpose: To study associations between early and late age-related macular degeneration (AMD) and neovascular AMD (nvAMD) with serum 25-hydroxy vitamin D (25(OH)D) and genetic variants in vitamin D pathway genes. Design: Population-based, cross-sectional study in a random sample aged 65 years or older from 7 European countries. Participants: Of...
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Biomass cooking fuels are commonly used by Indian households especially the poorest. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited. To examine the association of biomass cooking fuels with cataract and type of cataract. We conducted a population-based study in nor...
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The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 European participants. The aim of the consortium is to pr...
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Moderate vitamin B-12 deficiency is relatively common in older people. However, there is little robust evidence on the effect of vitamin B-12 supplementation on neurologic and cognitive outcomes in later life. We investigated whether vitamin B-12 supplementation benefits neurologic and cognitive function in moderately vitamin B-12-deficient older p...
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To investigate whether myopia is becoming more common across Europe and explore whether increasing education levels, an important environmental risk factor for myopia, might explain any temporal trend. Meta-analysis of population-based, cross-sectional studies from the European Eye Epidemiology (E(3)) Consortium. The E(3) Consortium is a collaborat...
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To estimate incidence of age related macular degeneration (AMD) by subtype in United States (US) whites aged ≥50 years. Systematic review and meta-analysis METHODS: SETTING: Prospective cohort studies of AMD incidence in populations of white European ancestry published in MEDLINE, EMBASE and Web of Science. - Fourteen publications in 10 populations...
Article
Objective The purpose of this study is to examine the association of the clock drawing test (CDT) with incident dementia, cardiovascular events and mortality in very elderly hypertensive patients.Method All participants were hypertensive and aged 80 years and over. The CDT was administered at baseline and annually thereafter. Data on incident cardi...
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To estimate the prevalence of refractive error in adults across Europe. Refractive data (mean spherical equivalent) collected between 1990 and 2013 from fifteen population-based cohort and cross-sectional studies of the European Eye Epidemiology (E3) Consortium were combined in a random effects meta-analysis stratified by 5-year age intervals and g...
Article
We have previously reported low concentrations of plasma ascorbate and low dietary vitamin C intake in the older Indian population and a strong inverse association of these with cataract. Little is known about ascorbate levels in aqueous humor and lens in populations habitually depleted of ascorbate and no studies in any setting have investigated w...
Article
Background: The results of the Hypertension in the Very Elderly Trial showed positive benefits from blood pressure-lowering treatment in those aged 80 and over. Method: An analysis by the pre-specified subgroups [age, sex, history of cardiovascular disease (CVD) and initial SBP] was performed. The Hypertension in the Very Elderly Trial was a ran...
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Individual participant time-to-event data from multiple prospective epidemiologic studies enable detailed investigation into the predictive ability of risk models. Here we address the challenges in appropriately combining such information across studies. Methods are exemplified by analyses of log C-reactive protein and conventional risk factors for...
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Although the number of individuals reaching 80 who are considered to be healthy is increasing, the very elderly are likely to have long-term conditions, to report symptoms and/or be taking at least one regular medication. The impact of antihypertensive treatment has to be taken into account in this context. The treatment regimen in Hypertension in...
Article
For nearly half a century, associations between aspirin use and aging macula disorder (also termed age-related macular degeneration [both AMD]) have been described, predominantly from case reports and small clinical studies. In the last year, the publication of more robust evidence from 3 population-based studies has reawakened interest in this que...
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Objective: To assess the relevance of tobacco smoking to cause-specific mortality in older men. Methods: In a prospective study of surviving participants of the Whitehall study of male civil servants initially recruited in 1967-1970, 7044 were resurveyed in 1997-8 (mean age 77 years; range 66-97), of which 7024 reported information on smoking habit...
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Purpose: To report on plasma/serum levels of antioxidant vitamin and carotenoids in older adults resident in multiple countries in Europe and examine relationships with potential modifiers. Methods: Population-based cross-sectional European Eye Study in 7 centres from northern to southern Europe. In total, 4,133 participants aged 65 years or ove...
Article
Objectives: High blood pressure (BP) has been associated with increased risk of dementia. Concerns have been raised about lowering BP too far in the very elderly and thereby increasing risk. There is some evidence to suggest a potential 'J'-shaped relationship between DBP and risk of cognitive impairment. This was investigated using data from the...
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The aim of this study is to systematically review quantitative studies exploring the association between social support (SS) and the health of older people in Middle Eastern countries. Sixteen electronic databases and other resources were searched to identify studies that met the inclusion criteria of the review. Abstracts of identified papers were...
Article
Objective: To study associations between severity stages of early and late age-related macular degeneration (AMD) and genetic variations in age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) and to investigate potential interactions between smoking and ARMS2. Design: Population-based, cross-sectional European Eye Stud...
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Purpose: To examine the association between a posteriori-derived dietary patterns (DP) and retinal vessel caliber in an elderly population. Methods: This was a cross-sectional study of 288 elderly adults (>65 years) who participated in the European Eye study (EUREYE) Northern Irish cohort. DP were extracted using principal component analysis fro...
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Purpose: Association between genetic variants in complement factor H (CFH), factor B (CFB), component 2 (C2), and in the ARMS2/HTRA1 region with age-related macular degeneration (AMD) comes mainly from studies of European ancestry and case-control studies of late-stage disease. We investigated associations of both early and late AMD with these var...
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Background: The extent to which adult height, a biomarker of the interplay of genetic endowment and early-life experiences, is related to risk of chronic diseases in adulthood is uncertain. Methods: We calculated hazard ratios (HRs) for height, assessed in increments of 6.5 cm, using individual-participant data on 174374 deaths or major non-fata...
Article
Background: numerous reports have linked impaired kidney function to a higher risk of cardiovascular events and mortality. There are relatively few data relating to kidney function in the very elderly. Methods: the Hypertension in the Very Elderly Trial (HYVET) was a randomised placebo-controlled trial of indapamide slow release 1.5mg ± perindop...
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We investigated whether previously reported single nucleotide polymorphisms (SNPs) of EPHA2 in European studies are associated with cataract in India. We carried out a population-based genetic association study. We enumerated randomly sampled villages in two areas of north and south India to identify people aged 40 and over. Participants attended a...
Article
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To examine the global prevalence and major risk factors for diabetic retinopathy (DR) and vision-threatening diabetic retinopathy (VTDR) among people with diabetes. A pooled analysis using individual participant data from population-based studies around the world was performed. A systematic literature review was conducted to identify all population...
Article
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UK estimates of age related macular degeneration (AMD) occurrence vary. To estimate prevalence, number and incidence of AMD by type in the UK population aged ≥50 years. Age-specific prevalence rates of AMD obtained from a Bayesian meta-analysis of AMD prevalence were applied to UK 2007-2009 population data. Incidence was estimated from modelled age...
Article
Full-text available
Variation in the complement factor H gene (CFH) is associated with risk of late age-related macular degeneration (AMD). Previous studies have been case-control studies in populations of European ancestry with little differentiation in AMD subtype, and insufficient power to confirm or refute effect modification by smoking. To precisely quantify the...
Article
Background: variation in the complement factor H gene (CFH) is associated with risk of late age-related macular degeneration (AMD). Previous studies have been case–control studies in populations of European ancestry with little differentiation in AMD subtype, and insufficient power to confirm or refute effect modification by smoking. Methods: to pr...
Article
Variation in the complement factor H gene (CFH) is associated with risk of late age-related macular degeneration (AMD). Previous studies have been case-control studies in populations of European ancestry with little differentiation in AMD subtype, and insufficient power to confirm or refute effect modification by smoking. METHODS: To precisely quan...
Article
To obtain prevalence estimates of age-related macular degeneration (AMD; late, geographic atrophy, neovascular) by age and gender amongst populations of European ancestry taking into account study design and time trends. Systematic review of population-based studies published by September 2010 with quantitative estimates of geographic atrophy (GA),...
Article
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Studies from the UK and North America have reported vitamin C deficiency in around 1 in 5 men and 1 in 9 women in low income groups. There are few data on vitamin C deficiency in resource poor countries. To investigate the prevalence of vitamin C deficiency in India. We carried out a population-based cross-sectional survey in two areas of north and...
Article
Age-related macular degeneration (AMD) is the most common cause of incurable visual impairment in high-income countries. Previous studies report inconsistent associations between AMD and apolipoprotein E (APOE), a lipid transport protein involved in low-density cholesterol modulation. Potential interaction between APOE and sex, and smoking status h...
Article
To assess if very elderly people with hypertension obtain early benefit from antihypertensive treatment. One year open label active treatment extension of randomised controlled trial (Hypertension in the Very Elderly Trial (HYVET)). Hospital and general practice based centres mainly in eastern and western Europe, China, and Tunisia. People on doubl...
Article
To study associations between aspirin use and early and late aging macula disorder (AMD). Population-based cross-sectional European Eye Study in 7 centers from northern to southern Europe. In total, 4691 participants 65 years of age and older, collected by random sampling. Aspirin intake and possible confounders for AMD were ascertained by a struct...
Article
Age-related macular degeneration (AMD) is the most common cause of incurable visual impairment in high-income countries. Previous studies report inconsistent associations between AMD and apolipoprotein E (APOE), a lipid transport protein involved in low-density cholesterol modulation. Potential interaction between APOE and sex, and smoking status h...