AUTOMATED PERIMETRY AND MALINGERERS - CAN THE HUMPHREY BE OUTWITTED

Background: Through detailed strategies and sophisticated analysis, th e Humphrey automated visual field analyzer attempts to indicate if vis ual field loss is artefactual. Can these measures be outwitted by mali ngerers? Methods: The author investigated the ease with which motivate d individuals (such as are malingerers) could simulate visual field de fects consistent with organic neurologic disease on the Humphrey visua l field analyzer. Visual field test results were analyzed for characte ristic features and compared with visual field tests from patients wit h documented pituitary tumors. Results: Volunteers, given only broad s uggestions as to the visual field they were to simulate, produced cons istent, convincing, neurologic-type field defects, according to textbo ok descriptions of such fields. These plotted fields were only disting uishable from genuine pituitary tumor Humphrey field tests, in that th ey more convincingly fitted the classic descriptions of visual fields seen with chiasmal compression. Conclusions: The author concludes that single routine Humphrey visual field tests do not show malingerers. A n incidental finding of this study was the extent to which Humphrey vi sual fields from patients with genuine neurologic disease contain fiel d defects with characteristics different from those of the (kinetic) v isual field test appearances described in the textbooks.