Figure 2.

Example of saccadic and fixation deficit in one patient with early Parkinson's disease. Horizontal eye positions are depicted with black trace; the gray trace represents the visual target position. (A) Saccade and fixation abnormality is summarized from one patient. There is hypometria of initial saccade and it is then followed by several hypometric corrective saccades (HS). Latter brings the gaze to the target. Horizontal lines in (A) depict the portion of the eye movement trace that is temporally zoomed in (B–D). Thick, horizontal, gray line is the target acquisition time. (C) Depicts an example of square-wave jerk (SWJ), while (D) shows “staircase” square-wave jerk. ISI, inter-saccadic interval. [Figure and legend reproduced with permission from (10)].