THE PURPOSE of this paper is to discuss the differential diagnosis of pareses of the superior rectus and superior oblique muscles in cases of vertical muscle imbalance with head tilt and full binocular vision. Six illustrative cases are presented.
PRESENTATION OF THE PROBLEM
The Duane-White1 school, in the vast majority of cases, assigned head tilt due to paresis of a superior muscle to initial paresis of a superior rectus. The proponents of the Bielschowsky2 theory consider this head tilt to be due to paralysis of a superior oblique muscle. Duanela stated that the head tilt in these cases is due to the fact that by the tilting the higher image is brought to a horizontal base line with the lower image, and thus one is rid of the vertical component. That the first part of this statement is true can easily be shown by placing a sufficiently