Relationship of Hypertropia and Excyclotorsion in Superior Oblique Palsy

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 5.09degrees +/- 3.84degrees. The subjective excyclotorsion degrees were 5.18degrees +/- 4.11degrees and 3.65degrees +/- 1.93degrees 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.

Contemplation of the Surgical Normogram of Lateral Rectus Recession for Exotropia Associated with Superior Oblique Palsy

PURPOSE: To suggest a surgical normogram for lateral rectus recession in exotropia associated with unilateral or bilateral superior oblique muscle palsy (SOP). METHODS: We retrospectively reviewed the charts of 71 patients with exotropia who were successfully corrected over one year. Each patient had undergone unilateral or bilateral rectus recession associated with uni- or bilateral inferior oblique (IO) 14 mm recession, using a modified surgical normogram for lateral rectus (LR) recession, which resulted in 1 to 2 mm of reduction of LR recession. We divided all patients into 2 groups, the 34 patients who had undergone LR recession with unilateral IO (UIO) recession group and the remaining 37 patients who had undergone LR recession with bilateral IO (BIO) recession group. Lateral incomitancy was defined when the exoangle was reduced by more than 20% compared to the primary gaze angle. The surgical effects (prism diopters [PD]/mm) of LR recession were compared between the two groups using the previous surgical normogram as a reference (Parks' normogram). RESULTS: The mean preoperative exodeviation was 20.4 PD in the UIO group and 26.4 PD in the BIO group. The recession amount of the lateral rectus muscle ranged from 4 to 8.5 mm in the UIO group and 5 to 9 mm in the BIO group. Lateral incomitancy was noted as 36.4% and 70.3% in both groups, respectively (p = 0.02). The effect of LR recession was 3.23 +/- 0.84 PD/mm in the UIO group and 2.98 +/- 0.62 PD/mm in the BIO group and there was no statistically significant difference between two the groups (p = 0.15). CONCLUSIONS: Reduction of the LR recession by about 1 to 2 mm was successful and safe to prevent overcorrection when using on IO weakening procedure, irrespective of the laterality of SOP.