Purpose: To evaluate the correlation between hypertropia and excyclotorsion in acquired superior oblique palsy (SOP).
Methods: Thirty-one patients with acquired unilateral SOP were recruited for this study. The torsional angle of each patient was assessed via one objective method (fundus photography) and two subjective methods (double Maddox rod test and major amblyoscope). The patient population was divided into two groups (concordance group, n = 19 and discordance group, n = 12) according to the correspondence between the hypertropic eye (paralytic eye) and the more extorted eye (non-fixating eye), which was evaluated by fundus photography.
Results: The mean value of objective torsion was 5.09° ± 3.84°. The subjective excyclotorsion degrees were 5.18° ± 4.11° and 3.65° ± 1.93° as measured by double Maddox rod test and major amblyoscope, respectively. Hypertropia and the excyclotorsional angle did not differ significantly between the groups (p = 0.257). Although no correlation was found in the discordance group, the concordance group showed a significant and positive correlation between hypertropia and excyclotorsion (p = 0.011).
Conclusions: Torsional deviation was not related to hypertropia. However, in the concordance patients in whom the hypertropic eye showed excyclotorsion, a significant positive correlation was found between hypertropia and excyclotorsion.
Keywords: Major amblyoscope; Noncomitantsuperior oblique palsy; Strabismus; Torsion.