Clinical Feature and Diagnosis in Masked Bilateral Superior Oblique Palsy

ABSTRACT

The preoperative diagnosis of the masked bilateral superior oblique palsy (SOP) is very diffcult, so the clinical manifestation is very important. We studied to determine diagonostic criteria of the masked bilateral SOP. Among 24 patients. who were diagnosed as unilateral SOP preoperatively, 5 patients developed postoperative masked bilateral SOP. 2 patients had been diagnosed masked bilateral SOP preoperatively. We compared 17 cases of unilateral SOP with seven cases of masked bilateral SOP about V-shift, head tilt test and the degree of excyclotorsion. The mean V-shift of the masked SOP patients was 5.3PD and that of the unilateral SOP patients was 1.5PD(p=0.09). The mean excyclotosion difference between the primary position and downgaze was 9.7 degree in masked cases and 2.6 degree in unilateral ones respectively (p=0.35). The mean difference of hyperdeviation the right versus the left tilted head position was 22PD in masked cases and 18.1PD in unilateral ones (p=0.35). The cases of excyclotorsion difference over 5 degrees between primary and downgaze were five(71%) in masked cases but none in unilateral cases(p=0.0001). So above finding may be strongly suggested as diagnosing the masked bilteral SOP.