Incomitant dissociated vertical deviation and superior oblique overaction.

When superior oblique overaction coexists with dissociated vertical deviation, it may produce a pattern of disparity in the amount of dissociated vertical deviation in different horizontal gaze fields, which the authors have termed incomitance. Seven patients with the constellation of esotropia, bilateral superior oblique overaction, "A"-pattern, and incomitant dissociated vertical deviation are presented. In each case, a distinctive incomitant pattern of dissociated vertical deviation was noted in which dissociated vertical deviation was least in adduction, moderate in primary position, and greatest in abduction. Four patients underwent asymmetric superior rectus recessions and partial tenotomy of the superior oblique tendons at their insertions as the initial treatment for their incomitant dissociated vertical deviation. Recognition of such a pattern of incomitant dissociated vertical deviation is important in choosing appropriate surgical management.