These guidelines serve as a basis for practitioners to evaluate their perimetric needs in relation to their clinical practice and patient population so that informed decisions can be made for visual field testing. In addition, these issues should be used as a cornerstone for future technological and practical improvements to the visual field diagnostic procedures.

The spatial relationship between anatomy and function in glaucoma was studied in 15 selected cases of focal damage. Based on planimetric data of the optic disc the anatomical site of damage was defined as the sector with the thinnest neuroretinal rim. Perimetric data were evaluated with regard to 21 regions of the 'Perimetric Nerve Fibre Bundle Map' (Weber & Ulrich 1990a). The site of damage was defined as those regions with at least 50% of depressed points. The site of the affected rim and the number of the corresponding Perimetric Nerve Fiber Bundles showed a linear correlation over a limited range of the superior and inferior pole of the disc. A 'functional disc map' could be established for 6 perimetric regions.

Temporal summation as the relation of threshold intensity to presentation time of a stimulus has been tested in different retinal locations under photopic and mesopic conditions in 35 normal subjects of all ages. The characteristics of temporal summation is quite independent of age, retinal location and adaptation of the eye. The only variable is the time of transition from complete to absent temporal summation, ranging from 32 msec in photopic foveal vision to more than 320 msec in mesopic peripheral vision

The Peritest is a new automatic and semi-automatic (manual) perimeter for detection and limited assessment of visual field defects. It uses either multiple or single stimulus static perimetry. The lightsources are LED's. A total of 206 positions can be examined including the center; 151 positions inside 25 degrees-eccentricity. The programmes use a threshold-related gradient adapted suprathreshold (0.6) strategy. The results are printed on a special chart using non-interpolated grey scales for indicating local reduction of sensitivity. General and local reduction of sensitivity are separated. The progress of the examination can be followed on a LED-monitor. The reliability of the patient is measured. 70% of small early glaucomatous defects (that are only found by high resolution meridional static perimetry) were detected. Such defects are not usually detected by routine kinetic perimetry. More peripheral defects were detected (greater than 25 degrees) than by kinetic perimetry. Due to the relatively high number of stimuli the typical configuration of defects was satisfactorily demonstrated for defects of moderate size and larger. The duration of the examination varies from less than 4 min. for a semi-automatic examination of normal eyes to 10-20 min. for automatic examination of eyes with defects of moderate size (average 15 minutes for 206 positions).

Evaluation of visual field findings is an essential ophthalmological task. Applying psychophysical principles enables non-invasive (topo-)diagnostics in case of unexplained visual loss or suspected lesions of the visual pathways. Furthermore, any kind of expert opinion or ability test depends critically on adequate visual field findings. Repeated examinations allow the functional follow-up of a disease and judgement of therapeutic efficiency. This paper is explicitly focused on conventional strategies of visual field examination, since these are widespread, easily accessible, standardized and well established in everyday practice. Part 1 of this continuing education series will mainly impart basic concepts in perimetry and psychophysics. It will also consider indications and the necessary general setup of a perimetric examination. Furthermore, a concept of scotoma classification is explained.