[Three-dimensional analysis of eye movements induced by roll and pitch tilt]

The torsional eye movements induced by the right and left ear-down position are known as "ocular counter-rolling" but the mechanism of the horizontal and vertical eye movements has not been clarified. The vertical eye movements induced by backward tilt are known as the "doll reflex", but clear eye movements are induced by forward tilt. The mechanism of horizontal and torsional eye movements are unclear. To detect 3D eye movements in the roll and pitch planes, we performed 3D analysis of eye movements by our video-oculographic method. During roll tilt, counter-torsional eye movements were clearly induced, but no definite, eye movements were observed in the horizontal and vertical components of eye movements. During pitch tilt, downward eye movements were observed following backward tilt, but no clear eye movements were observed following forward tilt. Moreover, no clear horizontal or torsional eye movements were observed during pitch tilt. These results suggest that the response to pitch tilt depends on the saccular input.