Ocular torsional movements in humans with normal and abnormal ocular motility--Part I: Objective measurements.

Using a corneal marker and cinematography, we analyzed ocular torsional movements during forced head tilt in three patients with superior oblique palsy before and after ipsilateral inferior oblique recession and compared them to those of normal subjects. As the head is tilted in normal subjects, the eye lags behind the head in a slow rolling movement. Periodic rapid wheel-like movements occur in the direction of head tilt which do not completely allow the eye to catch up with the head. This results in a partial compensatory intorsion on ipsilateral head tilt and extorsion on contralateral head tilt. In patients with superior oblique palsy, the rapid extorsional movement on ipsilateral head tilt is greater and faster than in the normal, but becomes slower after inferior oblique recession, indicating it comes from the overacting inferior oblique. The rapid intorsional movement seen during contralateral head tilt is absent in patients with superior oblique palsy, but appears in a diminished form after inferior oblique recession.