Single and Multiple Stimulus Static Perimetry in Glaucoma; The Two Phases of Perimetry : The Two Phases of Perimetry

does not vary more than 1 % over the whole surface. Stimulus: The luminance of the stimuli can be regulated by means of neutral density filters. These filters are neither entirely neutral nor completely uniform, but these variations are not significant for perimetry. The maximum luminance of the stimuli is standardized at 1000 asb (316 2 cd.m-). The standard GP for kinetic perimetry has 3 neutral density filters which reduce the luminance by 0.5, 1.0 and 1.5 log units respectively. The modification of the GP for static perimetry is supplied with an additional series of four neutral density filters, which allow luminance steps of 0.1, 0.2, 0.3 and 0.4 log units. The resulting luminance values, expressed in apostilb, are given in Table I. TABLE I Luminance values of the Goldmann perimeter 4 3 2 steps lux 1430 450 143 45 3,1 asb 1000 315 100 31,5 3,1 2 cd/m 315 100 31,5 10 3,1 ßL ±30 10 3 3,1 L log L asb 3 2,5 2 2 1,5 0,5 2 Background: 31,5 asb. = 10 cd/m • Coefficient of reflection 0,7. 1 2 (1 asb = -cd/m).

I. Introduction.- II. Some Basic Facts from Visual Physiology.- Visual Field Examination is a threshold measurement.- Methods of measurement.- Factors which determine the difference threshold.- Physical characteristics of the stimulation.- Determination of the position of the stimulus.- Level of luminance before examination.- Background luminance.- Luminance of stimulus.- Size of stimulus.- Sharpness of stimulus.- Presentation time.- Movement.- Chromaticity of the stimulus.- Fixation target.- Receptor and neural mechanisms.- Anatomical considerations.- Adaptation.- Definition and mechanisms.- Temporal adaptation; adaptometry.- Adaptation and the two receptor systems.- Steady state adaptation.- Adaptation and difference threshold.- Adaptation and topography of the light sensitivity; adapto-perimetry.- photopic level.- scotopic level.- mesopic level.- Equivalent background; the relationship between adaptometry and adaptoperimetry.- Conclusion.- Spatial interaction.- Psychophysical findings.- Laws of summation.- Summation and inhibition.- Electrophysiological findings.- Receptive field.- Summation area and receptive field.- Temporal interaction.- Psychophysical findings.- Data from the literature.- Broca-Sulzer effect.- Critical fusion frequency.- Local adaptation.- Movement.- Detection of movement.- Detection of direction.- Fixation.- Physiological fixation nystagmus.- Fixation and visual field examination.- III. The Fundamental Principles of Static and Kinetic Perimetry.- Static Perimetry.- Kinetic Perimetry.- The fundamental difference between static and kinetic perimetry.- Fundamental limits of the accuracy of kinetic perimetry.- movement; successive lateral spatial summation.- gradient of sensitivity.- sensitivity curves for static and kinetic stimuli.- influence of reaction time.- detection and reproducibility.- influence of direction of movement.- Conclusion.- IV. Choice of the Conditions of Examination.- Choice of adaptation level.- Selective detection of disturbances in the photopic or the scotopic system.- Visual field examination at mesopic adaptation levels.- Threshold examination at mesopic and photopic levels.- Intra-individual variation at various adaptation levels.- Influence of preretinal factors.- Scotopic perimetry.- High-photopic adaptation levels.- Conclusion.- Choice of stimulus size; spatial interaction and visual field examination.- Spatial interaction in the normal visual field.- Constant size of stimulus.- Dubois-Poulsen’s work: spatial interaction and visual field defects.- Problems of kinetic perimetry.- Inter-individual variation of the summation exponent.- Results obtained by other authors.- Inhibition in perimetric examinations.- Conclusion: Choice of stimulus size.- The significance of the examination of spatial summation in visual field defects.- Choice of presentation time; temporal interaction and visual field examination.- Temporal interaction in the normal visual field.- Position.- Adaptation.- Stimulus size.- Arguments for the use of a short presentation time.- intra- and inter-individual variation.- total duration of the examination.- latent period for eye movements.- normal fixation movements and temporal summation.- subjective experience.- abnormal temporal summation in visual field defects.- technical possibilities.- kinetic perimetry.- Conclusion.- Local adaptation and visual field examination.- Local adaptation in the normal visual field.- Local adaptation and visual field defects.- Conclusion.- Some remarks about critical fusion frequency (C.F.F.) and colour in visual field examination.- V. The Place of Static and Kinetic Perimetry in the two Phases of Visual Field Examination.- Detection phase.- present-day kinetic perimetry.- number and position.- size of stimulus.- size of defect.- conclusions about number and position.- static and kinetic perimetry in the detection phase.- subdivision of detection phase.- two separate halves of the visual field.- repeat examination.- static and kinetic perimetry in visual field defects.- Assessment phase.- VI. Three Instruments for Single Stimulus Visual Field Examination.- The Goldmann perimeter.- The Tübinger perimeter.- The Double Projection Campimeter.- VII. Normal Values and Normal Variation of Thresholdmeasurements.- Normal values and inter-individual variation.- Kinetic perimetry with the Goldmann perimeter.- Static perimetry with the Goldmann perimeter.- Kinetic perimetry with the Tübinger perimeter.- Static perimetry with the Tübinger perimeter.- Kinetic campimetry with the Double Projection Campimeter.- Static campimetry with the Double Projection Campimeter.- Intra-individual variation.- Causes of intra-individual variation.- Size of intra-individual variation.- Size of luminance steps and intra-individual variation.- Significance of defects.- Variations between successive examinations.- Influence of age.- Reaction time.- Position of the eye in the orbit.- Senile miosis.- Senile lens opacities.- Senile degeneration of the visual system.- Oxygen shortage.- Blind spot.- Optic disc and blind spot.- Pericecal visual field.- Size and position of the blind spot.- Angioscotomata.- Normal angioscotomata.- Variation in the size of angioscotomata.- Conclusion.- Cartography and visual field.- VIII. Multiple Static Stimuli in the Detection Phase.- Specific problems of multiple stimuli.- Simultaneous approach to the threshold.- Supraliminal stimuli.- Neural interaction.- ‘Gestalt’ psychological phenomena.- Counting and indicating.- Localized attention.- Maximum number of stimuli.- Threshold level and variation.- Pseudo-variation.- Multiple stimuli and visual field defects.- Instruments for multiple stimulus visual field examination.- Method of Harrington and Flocks.- Instrument of Fincham and Sutcliffe.- Friedmann Visual Field Analyser.- description and critical discussion.- examination with the Visual Field Analyser.- normal visual field with the Visual Field Analyser.- The Visual Field Analyser in the detection phase.- Literature and introduction.- False-negative results.- False-positive results.- Screening.- Optimum visual field examination using multiple stimuli.- Two other detection methods.- Armaly’s method.- Gloster’s method.- IX. Preretinal Factors.- Pupil.- Senile miosis.- Lens.- Ametropia.- Image formation in the emmetropic eye.- Image formation in the ametropic eye.- Central ametropia scotoma.- Correcting lenses.- Peripheral ametropia; refraction scotoma.- Accommodation.- Presbyopia and fatigue of accommodation.- Accommodation spasm due to miotics.- X. Description of Visual Field Defects.- Topography.- Definitions.- Numerical topographic classification.- Intensity.- Absolute and relative defects.- Quantitative determination of relative defects in static perimetry.- Intensity of defects in kinetic perimetry.- Distribution of intensity in defects.- XI. The Examination Procedure in Practice; Experiences with the Multiple Stimulus Method for the Detection of Glaucomatous Defects.- Examination procedure.- Research procedure.- Duration of the examination.- Organization.- Glaucomatous defects.- Early defects in the opposite hemifield.- Demonstration of 18 visual fields with glaucomatous defects.- Results of the comparative study.- Number and position of stimuli in the Visual Field Analyser.- Comparative study of threshold measurements.- Conclusion.- XII. Summary and conclusion.- References.