Afterimage versus photographic ocular torsionometry

Rotation of the eyeballs about the visual axis due to head tilt, counterocular torsion, can provide information relevant to the neuro-otologic status. Measurement of these reflexive movements, however, involves several difficulties. Two methods are examined: determinations by a behavioral afterimage technique are compared with those of a photographic method in the same subjects using a test-retest format. Results indicate that both procedures yield reliable measurements, and any differences tend to be inconsistent. Thus, the faster and less expensive afterimage technique appears suitable for many clinical purposes in assessing vestibulo-ocular function.