Learn More
This paper presents a new supervised method for segmentation of blood vessels in retinal photographs. This method uses an ensemble system of bagged and boosted decision trees and utilizes a feature vector based on the orientation analysis of gradient vector field, morphological transformation, line strength measures, and Gabor filter responses. The feature(More)
OBJECTIVES To determine by how much statins reduce serum concentrations of low density lipoprotein (LDL) cholesterol and incidence of ischaemic heart disease (IHD) events and stroke, according to drug, dose, and duration of treatment. DESIGN Three meta-analyses: 164 short term randomised placebo controlled trials of six statins and LDL cholesterol(More)
Retinal vessel segmentation algorithms are a fundamental component of automatic retinal disease screening systems. This work examines the blood vessel segmentation methodologies in two dimensional retinal images acquired from a fundus camera and a survey of techniques is presented. The aim of this paper is to review, analyze and categorize the retinal(More)
Littmann's formula relating the size of a retinal feature to its measured image size on a telecentric fundus camera film is widely used. It requires only the corneal radius, ametropia, and Littmann's factor q obtained from nomograms or tables. These procedures are here computerized for practitioners' convenience. Basic optical principles are discussed,(More)
BACKGROUND It is uncertain how best to screen pregnant women for the presence of fetal Down's syndrome: to perform first-trimester screening, to perform second-trimester screening, or to use strategies incorporating measurements in both trimesters. METHODS Women with singleton pregnancies underwent first-trimester combined screening (measurement of nuchal(More)
BACKGROUND UK estimates of age related macular degeneration (AMD) occurrence vary. AIMS To estimate prevalence, number and incidence of AMD by type in the UK population aged ≥50 years. METHODS 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(More)
A systematic review of cohort studies, randomized trials, voluntary notifications to national regulatory authorities, and published case reports was undertaken to assess the incidence and characteristics of adverse effects in patients treated with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins. For statins other than(More)
PURPOSE To quantify the variation in primary open-angle glaucoma (OAG) prevalence with age, gender, race, year of publication, and survey methodology. METHODS Medline, EMBASE, and PubMed were searched for studies of OAG prevalence. Studies with defined population samplings were sought. Forty-six published observational studies of OAG prevalence (103,567(More)
BACKGROUND Until the publication of the Serum Urine and Ultrasound Screening Study (SURUSS) report, it was difficult to compare the different antenatal screening tests for Down's Syndrome because of variations in study designs. We here present the main results from SURUSS, updated to take account of recent information on nuchal translucency in Down's(More)
AIMS To compare methods available to correct the magnification of images that result from the optics of the eye and identify errors, and source of error, of the methods. METHODS 11 methods were applied to ocular biometry data from three independent cohorts. Each method was compared with the method of Bennett, which uses most biometric data. The difference(More)