Clinical Evaluation of Superior Oblique Muscle PalsyAssociated with Horizontal Deviation

ABSTRACT

PURPOSE: The purpose of this study is to provide useful clinical information for proper diagnosis of the superior oblique muscle palsy (SOP) associated with horizontal deviation. METHODS: The records of 186 patients with SOP treated surgically were reviewed. The patients who underwent surgery for horizontal deviation more than 10 PD were classified into SOP associated with horizontal deviation. RESULTS: Of 186 patients with SOP, 96 (51.6%) patients also showed horizontal deviation. In 59 patients (61.5%) of these 96 patients, chief complaint was horizontal deviation only and 24 patients (25.0%) knew their hyperdeviation. Compensatory head-tilt was shown in 52 patients (54.2%), however only 11 (11.5%) patients complained their head-tilt posture. Of 96 patients, 72 (82.3%) had horizontal deviation in the eye contralateral to the paretic eye and amblyopia occurred in the horizontally deviated eye. The frequency of exodeviation was 82.3 % and was more than that of esodeviation. The mean amount of hyperdeviation was 12.6 +/- 6.77 PD, and that of horizontal deviation was 22.9 +/- 8.13 PD in exodeviation and 22.5 +/- 9.17 PD in esodeviation, respectively ninety three patients (96.9%) showed positive Bielschowsky head-tilt test. All 83 patients who had fundus examination showed foveal extorsion. CONCLUSIONS: This study reveals that Bielschowsky head-tilt test and fundus examination for foveal extorsion are needed to diagnose SOP which is masked by prominent horizontal deviation.