Figure 4.

Extraocular muscle function testing, showing a normal right eye; the left eye shows restriction on abduction, adduction, and upward gaze; no abnormality on downward gaze was observed. The ratings are based on 9-point scale, from +4 to —4: zero represents normal movement; negative scores indicate limitations in movement, in which —1 is a 25% deficit, —2 is a 50% deficit, —3 is a 75% deficit, and —4 represents no movement; and positive scores denote movement beyond normal, in which +1 is a 25% increase, +2 is a 50% increase, +3 is a 75% increase and +4 is a 100% increase (from Ref. 30).