[Efficacy of Vertical Muscle Transpositions with and without Simultaneous Rectus Muscle Recession for Unilateral Sixth Nerve Palsy].
We report results of a modified vertical muscle transposition procedure according to the Hummelsheim principle - with and without simultaneous rectus muscle recession - for unilateral sixth nerve palsy. We examine the influence of the duration of the palsy, preoperative angle of squint and preoperative abductive capacity on surgical results of the procedures. Retrospective study of 29 consecutive patients with unilateral abducens nerve palsy who underwent surgery between 2001 and 2012. 21 patients had a modified vertical rectus muscle transposition according to the Hummelsheim principle (HUM); 8 patients had this operation combined with simultaneous medial rectus muscle recession (HUM+I). Surgery was performed at least 9 months after onset of the palsy (HUM: 9 to 98, median 19, mean 30 months; HUM+I: 12 to 65, median 25, mean 29 months). The median preoperative angle of squint (far distance) for the HUM group was 27.0° (20.0 to 45.0; mean 28.1°), and for the HUM+I group 30.5° (21.8 to 50.0; mean 33.4°). The median preoperative abductive capacity was for - 1,6 mm before midline (- 8.0 to + 1.2; mean - 1.8 mm) for the HUM group, and - 3.0 mm before midline (- 10.0 to - 1.0; mean - 4.1 mm) for the HUM+I group. The median postoperative angle of squint (far distance) was 0° (- 11.3 to + 20.0; mean 0.1°) for the HUM group, and - 2.3° (- 11.3 to + 12.0; mean - 2.1°) for the HUM+I group. The median postoperative abductive capacity was 1.0 mm (0 to + 3.0; mean + 1.1 mm) for the HUM group, and 1.1 mm (- 1.2 to + 3.0; mean + 0.9 mm) for the HUM+I group. The median reduction of squint angle was 27.0° (9.1 to 45.0; mean 28.0°) for the HUM group, and 36.8° (25.2 to 41.4; mean 35.5°) for the HUM+I group. The median effect on abductive capacity was 2.5 mm (0 to 11.0; mean + 2.9 mm) for the HUM group, and 4.6 mm (2.4 to 8.8; mean + 5.0 mm) for the HUM+I group. In the HUM group, the effect on squint angle reduced with the duration of the palsy, whereas, in the HUM+I group, the effect improved with the duration of the palsy. For patients with unilateral sixth nerve palsy, simultaneous medial rectus recession increases the effect of modified vertical rectus muscle surgery according to the Hummelsheim principle. The duration of the palsy is a relevant parameter for the selection of a sole or combined intervention with medial rectus recession.
PubMed Abstracts
PubMed Abstracts