Detection and follow-up of homonymous visual field defects - perimetric essentials for evaluation of spontaneous recovery

Clinical detection and follow-up of homonymous visual field defects require appropriate perimetric procedures: since postgeniculate lesions are usuall y characterised by absolute scotomata, time consuming threshold methods can be replaced by supraliminal strategies with comparatively high stimulus de nsities. Compared with equidistant rectangular grids, a centripetal stimulu s condensation represents the physiological conditions more adequately and thus is more effective. It allows one to differentiate central changes of t he visual field, like macular sparing or splitting, which also interfere wi th reading performance. This procedure requires test points to be located t o either side of the vertical meridian, rather than directly on it. Multimo dal assessment of visual subfunctions (using static, kinetic or colour test points, random dot patterns or optokinetic stimulation) specifies the effe ct of the lesion in different channels or regions of the visual pathways. A utomation of perimetric procedures and continuous monitoring of fixation ar e important tools, enhancing the quality of examination and follow-up. The above mentioned psychophysical techniques for detection of functional d efects and documentation of eventual recovery, as well as matching neuroima ging findings, are demonstrated by illustrative cases.