[Disorders of eye movements in point fixation of the dominant eye in unilateral deprivation amblyopia, squint amblyopia and unilateral organ damage].

In four juvenile patients with unilateral deprivation amblyopia three types of involuntary eye movement were identified by simultaneous binocular infrared reflection oculography (IROG). During apparent steady-point fixation of the dominant eye three cases showed sinusoidal pendular movements (type 1) of the amblyopic eye mainly in a horizontal and slightly in a vertical direction, amplitude (A) 1 to 4 degrees, frequency (F) 0.25-0.4 Hz; only one patient had similar movements with smaller deviations even in the fixing eye. In three cases disturbed fixation of the dominant eye was found, a lateral drift (type 2) up to 3 degrees followed by slow correcting movement (F 0.05-0.1 Hz). At the same time there were disjugate movements of the amblyopic eye, the movements of the two eyes resulting in variations in squint angle of up to 6-7 degrees. These movements of the weaker eyes were clinically observed by Ohm (1958) and were termed pendular flutter to distinguish them from nystagmus. This paper presents the first objectively recorded curves of these movements, and differentiates them according to the various types of movement. Type 3 is a fine jerky or pendular nystagmus (A = max. 1 degree, F = 1.0-2.8 Hz), which was also present in three cases. Two patients had a combination of all three types of motility disturbance. Four cases with unilateral organ lesions, either congenital or acquired in early infancy, were observed and compared. All these cases showed excessive pendular flutter (type 1)--horizontal in the case of the fixing eye and horizontal and vertical in the case of the weaker eye.(ABSTRACT TRUNCATED AT 250 WORDS)