Compensatory head tilt in patients with superior oblique muscle palsy does not decrease excyclotropia

This study's author prospectively examined the effect of forced head tilt to the right and left on torsion and hypertropia in 20 of his patients with unilateral superior oblique muscle palsy. During forced head tilt from the head-erect position toward the contralateral side, subjects had a mean decrease in hypertropia of 6.4^Δ ± 3.9^Δ. This represented a significant decrease of 62 percent from the head-erect position. The mean decrease in excyclotropia was 0.25º ± 0.6º, a nonsignificant change of 3 percent. The percentage decrease in hypertropia was significantly greater than the percentage decrease in excyclotropia. The author concluded that compensatory head tilt in patients with superior oblique muscle palsy is not associated with a decrease in the excyclotropia and may serve the purpose of decreasing vertical rather than torsional misalignment.