Visual Fields

Introduction: Definition of the visual field; Extent of the normal visual field; Island of vision; Presentation of visual field data; Why do we measure the visual field?; Units of measurement; Psychophysics: Background luminance; Stimulus size; Stimulus presentation time; Stimulus speed of movement; Colour of stimulus; Psychological factors: the frequency-of-seeing curve; Strategies used in examining the visual field - Kinetic examination strategies; Static examination strategies; Alternative strategies for examining the visual field - Blue-yellow perimetry; High pass resolution perimetry; Frequency doubling perimetry; Amsler charts; Confrontation test; Oculokinetic perimetry; Extraneous factors which affect the visual field: The effect of age upon the visual field; Pupil size; Refractive error and defocus; Correcting lens artefact; Eyelid, eyelashes and eyebrow; Accuracy of fixation; Fixation targets; Provision of an audible tone prior to stimulus presentation; Patient experience - the learning effect; Fatigue effects; Lens and media opacities; Aphakia; Angioscotoma; Functional field loss (malingering and hysteria); Adaptation; Visual pathways: Retina; The optic nerve; The chiasma; The optic tracts; The lateral geniculate body; Optic radiations; The visual cortex; The differential diagnosis of visual field defects; Glaucoma: Glaucomatous field defects; Differences between normal-tension and high-tension glaucomas; Screening for visual field loss: The design of visual field screening tests; Position of stimuli; Number of stimuli; Pass/fail criteria; Quantification of visual field data: Introduction and the value of quantification; Variability; Evaluating quantification systems; The development of quantification systems; Types of quantification systems; Practical advice on how to conduct a visual field examination: Procedure to be adopted prior to any visual field examination; Kinetic strategy for wall mounted tangent screens (central 30 degrees); Kinetic strategy for bowl perimeters; Static suprathreshold examination (multiple stimulus); Static suprathreshold examination (single stimulus); Static threshold perimetry; Establishing the threshold prior to a threshold-related suprathreshold strategy; Visual field instruments: Bjerrum screen; Dicon TKS 5000, LD 400 and SST Autoperimeters; Friedmann Visual Field Analyser Mark I and Mark II; Goldmann bowl perimeter; Henson perimeters; Humphrey Visual Field Analyzers; Octopus perimeters.