Nov. 27, 2022
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Single Maddox rod test: measuring horizontal ocular misalignment in patient with right fourth and sixth cranial nerve palsies. (A) Maddox rod is placed in front of right eye with cylinders stacked horizontally as patient views a bright light (not shown in this frame). (B) Patient sees a vertical red line (with right eye) that is displaced to the right of the light, indicating an esodeviation. (C) Horizontal prism bar is placed base-out in front of Maddox rod and positioned such that the patient reports that the vertical red line has moved leftward so that it now appears to the patient to pass through the fixation light. (D) The amount of prism-diopters (read off the prism bar) necessary to bring the light into this position is the measure of the degree of esodeviation. (Contributed by Dr. Kara Warden.)