Fig. 15. Electro-oculographic recording in a patient with myasthenia gravis. Upper tracing: optokinetic-induced nystagmus before administration of edrophonium, drum rotating left (l) to right (r). Movements are of low amplitude and have a slow recovery phase to the left. Lower tracing: after administration of edrophonium, the amplitude of nystagmus is increased and recovery saccades to the left are rapid. No fatigue effect is seen. (Metz HS, Scott AB, O'Meara DM: Saccadic eye movements in myasthenia gravis. Arch Ophthalmol 89:9, 1972. Copyright 1972, American Medical Association)