U. Schiefer et al., Detection and follow-up of homonymous visual field defects - perimetric essentials for evaluation of spontaneous recovery, REST NEUROL, 15(2-3), 1999, pp. 201-217
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.