Dataset Information

Laser scanning tomography in the EPIC-Norfolk Eye Study: principal components and associations.

ABSTRACT: To describe Heidelberg Retina Tomograph (HRT) measures, their principal components, and their associations in a British population.The European Prospective Investigation of Cancer (EPIC)-Norfolk Eye Study is nested within a multicenter cohort study. Measurements were taken with the HRT-2 and the software subsequently updated to yield HRT-3 parameters. Principal components analysis (PCA) was used to identify distinct components of the HRT variables. Generalized estimating equation models were used to examine associations of these components with age, sex, height, body mass index (BMI), blood pressure, social class, education, alcohol intake, smoking status, axial length, IOP, and lens status.Complete data were available from 10,859 eyes of 6430 participants with a mean age of 68 years. Principal components analysis identified three components with an eigenvalue greater than 1, explaining 79.9% of the variance of all the HRT measures. These were named cup, retinal nerve fiber layer (RNFL), and rim based on the factor loadings they were most correlated with. Older age was significantly associated with a greater cup (P = 0.003), smaller RNFL (P < 0.001), and smaller rim (P < 0.001). Female sex (P = 0.001), higher education (P < 0.001), and shorter axial length (P < 0.001) were associated with a greater RNFL. Lower BMI and higher IOP were associated with a greater cup (both, P < 0.001) and a smaller rim (BMI, P = 0.001; IOP, P < 0.001).Heidelberg Retina Tomograph measures in this cohort were largely explained by three principal components related to optic disc cup, RNFL, and rim. Associations with cup and rim were distinct to associations with RNFL, suggesting different underlying determinants.

SUBMITTER: Khawaja AP

PROVIDER: S-EPMC3803136 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Laser scanning tomography in the EPIC-Norfolk Eye Study: principal components and associations.

Khawaja Anthony P AP Chan Michelle P Y MP Broadway David C DC Garway-Heath David F DF Luben Robert R Yip Jennifer L Y JL Hayat Shabina S Khaw Kay-Tee KT Foster Paul J PJ

Investigative ophthalmology & visual science 20131009 10

<h4>Purpose</h4>To describe Heidelberg Retina Tomograph (HRT) measures, their principal components, and their associations in a British population.<h4>Methods</h4>The European Prospective Investigation of Cancer (EPIC)-Norfolk Eye Study is nested within a multicenter cohort study. Measurements were taken with the HRT-2 and the software subsequently updated to yield HRT-3 parameters. Principal components analysis (PCA) was used to identify distinct components of the HRT variables. Generalized est ...[more]

PMID: 24030456

Similar Datasets

Project description:ObjectiveTo determine the association between systemic medication use and intraocular pressure (IOP) in a population of older British men and women.DesignPopulation-based, cross-sectional study.ParticipantsWe included 7093 participants from the European Prospective Investigation into Cancer-Norfolk Eye Study. Exclusion criteria were a history of glaucoma therapy (medical, laser, or surgical), IOP asymmetry between eyes of >5 mmHg, and missing data for any covariables. The mean age of participants was 68 years (range, 48-92) and 56% were women.MethodsWe measured IOP using the Ocular Response Analyzer. Three readings were taken per eye and the best signal value of the Goldmann-correlated IOP value considered. Participants were asked to bring all their medications and related documentation to the health examination, and these were recorded by the research nurse using an electronic case record form. The medication classes examined were angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, α-blockers, β-blockers, calcium channel blockers, diuretics, nitrates, statins, insulin, biguanides, sulfonylureas, aspirin, and other nonsteroidal anti-inflammatory drugs. We examined associations between medication use and IOP using multivariable linear regression models adjusted for age, sex, and body mass index. Models containing diabetic medication were further adjusted for glycosylated hemoglobin levels.Main outcome measuresMean IOP of the right and left eyes.ResultsUse of systemic β-blockers (-0.92 mmHg; 95% CI, -1.19, -0.65; P<0.001) and nitrates (-0.63 mmHg; 95% CI, -1.12, -0.14; P = 0.011) were independently associated with lower IOP. The observed associations between statin or aspirin use with IOP were no longer significant after adjustment for β-blocker use.ConclusionsThis is the first population-based study to demonstrate and quantify clinically significant differences in IOP among participants using systemic β-blockers or nitrates. Lower IOP observed in participants using statins or aspirin was explained by concurrent systemic β-blocker use. The study findings may have implications for the management of glaucoma patients with comorbidity, and may provide insight into the pathophysiologic processes underlying IOP.

Project description:BackgroundCognition covers a range of abilities, such as memory, response time and language, with tests assessing either specific or generic aspects. However differences between measures may be observed within the same individuals.ObjectiveTo investigate the cross-sectional association of cognitive performance and socio-demographic factors using different assessment tools across a range of abilities in a British cohort study.MethodsParticipants of the European Prospective Investigation of Cancer (EPIC) in Norfolk Study, aged 48-92 years, underwent a cognitive assessment between 2006 and 2011 (piloted between 2004 and 2006) and were investigated over a different domains using a range of cognitive tests.ResultsCognitive measures were available on 8584 men and women. Though age, sex, education and social class were all independently associated with cognitive performance in multivariable analysis, different associations were observed for different cognitive tests. Increasing age was associated with increased risk of a poor performance score in all of the tests, except for the National Adult Reading Test (NART), an assessment of crystallized intelligence. Compared to women, men were more likely to have had poor performance for verbal episodic memory, Odds Ratio, OR = 1.99 (95% Confidence Interval, 95% CI 1.72, 2.31), attention OR = 1.62, (95% CI 1.39, 1.88) and prospective memory OR = 1.46, (95% CI 1.29, 1.64); however, no sex difference was observed for global cognition, OR = 1.07 (95%CI 0.93, 1.24). The association with education was strongest for NART, and weakest for processing speed.ConclusionAge, sex, education and social class were all independently associated with performance on cognitive tests assessing a range of different domains. However, the magnitude of associations of these factors with different cognitive tests differed. The varying relationships seen across different tests may help explain discrepancies in results reported in the current literature, and provides insights into influences on cognitive performance in later life.

Project description:PurposeTo examine retinal vasculometry associations with different glaucomas in older British people.DesignCross-sectional study.MethodsA total of 8,623 European Prospective Investigation into Cancer-Norfolk Eye study participants were examined, who underwent retinal imaging, ocular biometry assessment, and clinical ascertainment of ocular hypertensive or glaucoma status (including glaucoma suspect [GS], high-tension open-angle glaucoma [HTG], and normal-tension glaucoma [NTG]). Automated measures of arteriolar and venular tortuosity, area, and width from retinal images were obtained. MainOutcomeMeasures: Associations between glaucoma and retinal vasculometry outcomes were analyzed using multilevel linear regression, adjusted for age, sex, height, axial length, intraocular and systemic blood pressure, and within-person clustering, to provide absolute differences in width and area, and percentage differences in vessel tortuosity. Presence or absence of within-person-between-eye differences in retinal vasculometry by diagnoses were examined.ResultsA total of 565,593 vessel segments from 5,947 participants (mean age 67.6 years, SD 7.6 years, 57% women) were included; numbers with HTG, NTG, and GS in at least 1 eye were 87, 82, and 439, respectively. Thinner arterioles (-3.2 μm; 95% confidence interval [CI] -4.4 μm, -1.9 μm) and venules (-2.7 μm; 95% CI -4.9 μm, -0.5 μm) were associated with HTG. Reduced venular area was associated with HTG (-0.2 mm2; 95% CI -0.3 mm2, -0.1 mm2) and NTG (-0.2 mm2; 95% CI -0.3 mm2, -0.0 mm2). Less tortuous retinal arterioles and venules were associated with all glaucomas, but only significantly for GS (-3.9%; 95% CI -7.7%, -0.1% and -4.8%; 95% CI -7.4%, -2.1%, respectively). There was no evidence of within-person-between-eye differences in retinal vasculometry associations by diagnoses.ConclusionsRetinal vessel width associations with glaucoma and novel associations with vessel area and tortuosity, together with no evidence of within-person-between-eye differences in retinal vasculometry, suggest a vascular cause of glaucoma.

Dataset Information

Laser scanning tomography in the EPIC-Norfolk Eye Study: principal components and associations.

Publications

Laser scanning tomography in the EPIC-Norfolk Eye Study: principal components and associations.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets