[Cyclofusion measurements for assessing the function of the oblique eye muscles (author's transl)].

In free space a random-dot-stereogramme for the determination of the extent of cyclofusion is used with the help of a haploscope. In the normal person orthophoria with regard to rolling to within +/- 1 degrees is found not only in the primary position but also in the secondary and tertiary positions and with head tilt. From the fact that with circular rotation of both eye images against each other pseudostereoscopic effects occur, it is deduced that the cyclofusion seen here occurred sensorially. The testing of the area of cyclofusion gives a very good basis for determining the indication for operation on the superior oblique muscle. It is shown with examples that simply tucking this muscle when old trochlear nerve paresis is present without provable excyclotropia is not favorable. Instead one must tuck the muscle asymmetrically in such cases--the fold should be markedly smaller at the anterior border of the muscle which acts more as a rotator, than at the posterior border.