0000000000398713

AUTHOR

Usha Chakravarthy

0000-0002-2606-3734

showing 12 related works from this author

Prevalence and Risk Factors for Vitamin C Deficiency in North and South India: A Two Centre Population Based Study in People Aged 60 Years and Over

2011

BackgroundStudies 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.ObjectivesTo investigate the prevalence of vitamin C deficiency in India.DesignWe carried out a population-based cross-sectional survey in two areas of north and south India. Randomly sampled clusters were enumerated to identify people aged 60 and over. Participants (75% response rate) were interviewed for tobacco, alcohol, cooking fuel use, 24 hour diet recall and underwent anthropometry and blood collection. Vitamin C was measured using an enzyme-based assay in plasma stabilized …

GerontologyMaleNon-Clinical Medicine030309 nutrition & dieteticsCross-sectional studyEpidemiologyPrevalencelcsh:MedicineAscorbic Acid0302 clinical medicineRisk FactorsPrevalence030212 general & internal medicinePoisson DistributionGeriatric Ophthalmologylcsh:ScienceMedicine(all)2. Zero hunger0303 health scienceseducation.field_of_studyMultidisciplinaryAgricultural and Biological Sciences(all)Anthropometry1. No povertyEpidemiology of AgingVitaminsMiddle Aged3. Good healthMedicineFemalePublic HealthSeasons/dk/atira/pure/subjectarea/asjc/2700Research ArticleClinical Research DesignPopulationIndia/dk/atira/pure/subjectarea/asjc/130003 medical and health sciencesEnvironmental health/dk/atira/pure/subjectarea/asjc/1100medicineHumansAscorbic Acid DeficiencyeducationBiologyNutritionAgedElderly CareHealth Care PolicyVitamin CPopulation BiologyBiochemistry Genetics and Molecular Biology(all)business.industrylcsh:RMalnutritionHealth Risk AnalysisAnthropometrymedicine.diseaseAscorbic acidMalnutritionOphthalmologyCross-Sectional StudiesGeriatricsMultivariate AnalysisAscorbic Acid Deficiencylcsh:QbusinessPLoS ONE
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Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive err…

2020

Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects …

genetic structureslikinäköisyyssense organsgeneettiset tekijäteye diseases
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Prevalence of early and late age-related macular degeneration in India: the INDEYE study.

2010

Purpose.: To estimate the prevalence of early and late age-related macular degeneration (AMD) in India. Methods.: Of 7518 people aged 60 years and older identified from randomly sampled villages in North and South India, 5853 (78%) attended an eye examination including fundus photography. Fundus images were graded according to the Wisconsin Age-Related Maculopathy Grading System. Results.: Fundus images were ungradable in 1587 people, mainly because of cataract. People 80 years of age and older were less likely to attend the eye examination and more likely to have ungradable images. For ages 60 to 79 years, the percent prevalence (95% confidence interval [CI]) were late AMD 1.2 (0.8–1.5); a…

Rural Populationmedicine.medical_specialtyUrban Populationgenetic structuresVisual AcuityPrevalenceIndiaDiagnostic Techniques OphthalmologicalDrusenFundus (eye)Macular DegenerationAge DistributionOphthalmologyEpidemiologyPrevalencemedicineHumansSex DistributionAgedAged 80 and overmedicine.diagnostic_testbusiness.industryFundus photographyArticlesMiddle AgedMacular degenerationmedicine.diseaseeye diseasesEye examinationMaculopathysense organsbusiness
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Genetic variants in a sodium-dependent vitamin C transporter gene and age-related cataract

2018

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, may provide evidence on a causal association of vitamin C with cataract. METHODS: We used data from a randomly selected population-based study in people aged 60 years and above in north and south India. Of 7518 sampled, 5428 (72%) were interviewed for socioeconomic and lifestyle factors, attended hospital for lens imaging and blood collection and wer…

Malegenetic structuresGenotypeIndiaClinical ScienceascorbateMiddle Agedeye diseasesCataractlens and zonulesSocioeconomic FactorsRisk FactorsHumansepidemiologygeneticsFemalesense organs15061507Life StyleSodium-Coupled Vitamin C TransportersAgedThe British Journal of Ophthalmology
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EPHA2 polymorphisms and age-related cataract in India.

2012

Objective: We investigated whether previously reported single nucleotide polymorphisms (SNPs) of EPHA2 in European studies are associated with cataract in India. Methods: 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 clinical examination including lens photography and provided a blood sample for genotyping. Lens images were graded by the Lens Opacification Classification System (LOCS III). Cataract was defined as a LOCS III grade of nuclear >= 4, cortical >= 3, posterior sub-capsular (PSC) >= 2, or dense opacities or aphakia/pseudophakia i…

MaleAnatomy and Physiologygenetic structuresEpidemiologymedicine.medical_treatmentlcsh:Medicine0302 clinical medicinePrevalencelcsh:ScienceGenetics0303 health scienceseducation.field_of_studyMultidisciplinaryReceptor EphA2Age FactorsMiddle Aged3. Good healthPhenotypeMedicineFemaleAge-related cataractResearch ArticleAdultmedicine.medical_specialtyGenotypePopulationIndiaSingle-nucleotide polymorphismPolymorphism Single NucleotideCataractWhite People03 medical and health sciencesCataractsOcular SystemOphthalmologyGeneticsmedicineHumansGenetic Predisposition to DiseaseeducationBiologyAged030304 developmental biologyPopulation Biologybusiness.industrylcsh:RHuman GeneticsOdds ratioCataract surgerymedicine.diseaseeye diseasesGenotype frequencyMinor allele frequencyOphthalmology030221 ophthalmology & optometrylcsh:QPhysiological ProcessesbusinessPopulation Genetics
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Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study.

2015

BACKGROUND: Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited. OBJECTIVES: To examine the association of biomass cooking fuels with cataract and type of cataract. METHODS: We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), ant…

Malegenetic structuresHealth Toxicology and MutagenesisEye diseaseBiomassIndia010501 environmental sciences01 natural sciencesCataractKerosene03 medical and health sciences0302 clinical medicineCataract epidemiologyRisk FactorsEnvironmental healthPrevalenceMedicineHumansBiomassCookingSocioeconomic status0105 earth and related environmental sciencesAgedAged 80 and overbusiness.industryCooking methodsResearchPublic Health Environmental and Occupational Healthfood and beveragesMiddle Agedmedicine.diseaseeye diseases3. Good healthPopulation based studyAir Pollution Indoor030221 ophthalmology & optometryOptometryFemalebusinessEnvironmental health perspectives
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Inverse association of vitamin C with cataract in older people in India.

2011

OBJECTIVE: To examine the association between vitamin C and cataract in the Indian setting. DESIGN: Population-based cross-sectional analytic study. PARTICIPANTS: A total of 5638 people aged ≥60 years. METHODS: Enumeration of randomly sampled villages in 2 areas of north and south India to identify people aged ≥60 years. Participants were interviewed for socioeconomic and lifestyle factors (tobacco, alcohol, household cooking fuel, work, and diet); attended a clinical examination, including lens photography; and provided a blood sample for antioxidant analysis. Plasma vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid, and other antioxidants wer…

Malegenetic structuresCross-sectional studyalpha-TocopherolAscorbic AcidXanthophyllsAntioxidantschemistry.chemical_compound0302 clinical medicineRisk FactorsPrevalence030212 general & internal medicineChromatography High Pressure Liquid2. Zero hungereducation.field_of_studyRetinolMiddle Agedbeta Carotene3. Good health/dk/atira/pure/subjectarea/asjc/2700/2731FemaleOriginal ArticlePosterior subcapsular cataractVitaminmedicine.medical_specialtyPopulationIndiaEnzyme-Linked Immunosorbent AssayCataract03 medical and health sciencesZeaxanthinsInternal medicinemedicineHumanseducationAgedVitamin Cbusiness.industryLuteinOdds ratioAscorbic acideye diseasesSurgeryOphthalmologyCross-Sectional Studieschemistry030221 ophthalmology & optometryAscorbic Acid Deficiencysense organsbusiness
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Prevalence and risk factors for myopia and other refractive errors in an adult population in southern India.

2018

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 measurement and objective and subjective measurement of refractive status. Myopia was defined as spherical equivalent (SE) worse than -0.75 dioptres (D), hyperopia as SE ≥+1D and astigmatism as cylinder <-0.5. RESULTS: The age-standardised prevalences of myopia, hyperopia and astigmatism were 35.6% (95% CI: 34.7-36.6), 17.0% (95% CI: 16.3-17.8) and 32.6 (…

genetic structureseye diseases
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Evolving European guidance on the medical management of neovascular age related macular degeneration

2006

BACKGROUND: Until recently, only two options were available for the treatment of choroidal neovascularisation (CNV) associated with age related macular degeneration (AMD)-thermal laser photocoagulation and photodynamic therapy with verteporfin (PDT-V). However, new treatments for CNV are in development, and data from phase III clinical trials of some of these pharmacological interventions are now available. In light of these new data, expert guidance is required to enable retina specialists with expertise in the management of AMD to select and use the most appropriate therapies for the treatment of neovascular AMD. METHODS: Consensus from a round table of European retina specialists was obt…

medicine.medical_specialtygenetic structuresBevacizumabAntibodies Monoclonal HumanizedTriamcinolone AcetonideMacular DegenerationCellular and Molecular NeuroscienceRanibizumabOphthalmologymedicineHumansPregnadienediolsEvidence-Based Medicinemedicine.diagnostic_testbusiness.industryAntibodies MonoclonalAptamers NucleotideMacular degenerationFluorescein angiographymedicine.diseaseVerteporfinChoroidal Neovascularizationeye diseasesSensory SystemsOphthalmologyTreatment Outcomemedicine.anatomical_structureChoroidal neovascularizationPhotochemotherapyPerspectivesense organsAnecortave acetateChoroidRanibizumabmedicine.symptombusinessmedicine.drugBritish Journal of Ophthalmology
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Prevalence of Cataract in an Older Population in India

2011

Purpose To describe the prevalence of cataract in older people in 2 areas of north and south India. Design Population-based, cross-sectional study. Participants Randomly sampled villages were enumerated to identify people aged ≥60 years. Of 7518 enumerated people, 78% participated in a hospital-based ophthalmic examination. Methods The examination included visual acuity measurement, dilatation, and anterior and posterior segment examination. Digital images of the lens were taken and graded by type and severity of opacity using the Lens Opacity Classification System III (LOCS III). Main Outcome Measures Age- and gender-standardized prevalence of cataract and 95% confidence intervals (CIs). W…

MaleAgingmedicine.medical_specialtyVisual acuityQuality Assurance Health Caregenetic structuresCross-sectional studyEye diseaseVisual AcuityPrevalenceIndiaCataract03 medical and health sciencesAge Distribution0302 clinical medicineRisk FactorsOphthalmologyEpidemiologyPrevalencemedicineHumans030212 general & internal medicineSex DistributionAgedbusiness.industryMiddle Agedmedicine.diseaseeye diseasesConfidence interval3. Good healthPosterior segment of eyeballOphthalmologyCross-Sectional Studies030221 ophthalmology & optometryOriginal ArticleFemalesense organsPosterior subcapsular cataractmedicine.symptombusinessOphthalmology
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Prevalence of Age-Related Macular Degeneration in Europe

2017

Manuscript no. 2016-1147 Supplemental material is available at www.aaojournal.org/; International audience; [u]Purpose:[/u] 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 Epidemiology (E3) consortium, and made projections for the future. [u]Design:[/u] Meta-analysis of prevalence data. [u]Participants:[/u] A total of 42 080 individuals 40 years of age and older participating in 14 population-based cohor…

0301 basic medicinemedicine.medical_specialtyVisual acuityOPTICAL COHERENCE TOMOGRAPHYMACULOPATHYgenetic structuresPopulationPrevalenceHEART-DISEASEchoroidal neovascularizationSensory disorders Donders Center for Medical Neuroscience [Radboudumc 12]03 medical and health sciencesRotterdam Study0302 clinical medicineAll institutes and research themes of the Radboud University Medical CenterBEAVER DAM EYEEpidemiologygeographic atrophymedicineVISUAL IMPAIRMENT[SDV.MHEP.OS]Life Sciences [q-bio]/Human health and pathology/Sensory OrganseducationPOPULATIONeducation.field_of_studyBIRTH COHORTbusiness.industryMacular degenerationmedicine.diseaseTRENDSConfidence intervaleye diseases3. Good healthEuropean Prospective Investigation into Cancer and NutritionOphthalmology030104 developmental biologyAge-related Macular DegenerationENDOTHELIAL GROWTH-FACTORBLINDNESS030221 ophthalmology & optometryOptometryAge-related Macular Degeneration choroidal neovascularization geographic atrophysense organsmedicine.symptombusiness[SDV.MHEP]Life Sciences [q-bio]/Human health and pathologyDemography
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Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and me…

2017

PubMed: 28779882

AFRICAPopulation ageingmedicine.medical_specialtyVisual acuity[SDV]Life Sciences [q-bio]PopulationVisual impairmentVision DisordersVisual AcuityEYEBlindnessGlobal Health03 medical and health sciences0302 clinical medicineSDG 3 - Good Health and Well-being[SDV.IDA]Life Sciences [q-bio]/Food engineeringPrevalenceJournal ArticleGlobal healthHumansMedicineVISUAL IMPAIRMENT[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering030212 general & internal medicineeducationPublic Environmental & Occupational Healtheducation.field_of_studyScience & Technologybusiness.industryMORTALITYPublic healthlcsh:Public aspects of medicineMedicine (all)COSTlcsh:RA1-1270General MedicinePresbyopiamedicine.diseaseVision Loss Expert Group3. Good healthMeta-analysis030221 ophthalmology & optometry/dk/atira/pure/sustainabledevelopmentgoals/good_health_and_well_beingHEALTHmedicine.symptombusinessLife Sciences & BiomedicineDemography
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