Critical perimetry - functioning methods.

Visual field defects without any organic correlate require critical control to avoid inadequate management of psychogenic defects. Which methods are promising to detect psychogenic visual field defects? Twenty ophthalmologically trained volunteers motivated to pretend a concentric visual field loss were tested by manual perimetry with centripetal and centrifugal movement of the stimulus, by evoking saccadic eye movements towards a stimulus outside the subjectively claimed visual field and by observation of the volunteers' strategy searching a stimulus beyond the subjectively claimed borders. Malingering could be proven in 16 persons. The most favourable procedure is to evoke eye movements towards a peripheral stimulus. These movements yield information about the visual field outside the subjectively stated limits.