[Surgical treatment for correcting abnormal complicated head posture in nystagmus].

Objective: To demonstrate the surgical choices for patients with complicated head posture associated with nystagmus.

Methods: It was a retrospective clinical study. Thirty-eight cases of congenital nystagmus with abnormal head posture in all three axes without strabismus were retrospectively analyzed. Twenty-nine(76.32%) cases whose dominant head posture were with face turn, 3 cases (7.89%) with chin up or down , respectively, were performed horizontal null zone shift as well as vertical null zone transposition; 2 cases (5.26%) with head tilt as the dominant position were underwent one tendon width transposition of all four vertical muscles;4 cases (10.53%)basically with the same degree for face turn and chip up or down, 2 cases were preferred with recess a group of horizontal yoke muscles and a group of vertical yoke muscles, the other 2 cases were combined with weaken both synergistic oblique muscles. SPSS 13.0 was used to analyse the difference of them.

Results: In 29 patients with horizontal head posture dominanted, 15 cases (68.18%) with 25 °-30 ° in horizontal head posture were corrected completely, 5°-15° was the residue for 7 cases (31.82%) with 35 °- 40 °degree in horizontal before surgery. 15 °-20° was residue for 3 cases larger than 40 ° before operation after modified Parks procedure. Anderson procedure can correct the angle of 15°-20° in 4 cases. The horizontal, vertical and torsional components of 22 cases whose predominant head posture were in horizontal with 25°-40° (3.18° ± 1.01°, 4.32° ± 1.14°, 4.55° ± 1.95°) were significantly reduced (t = 63.13, 3.57, 3.95;P < 0.01) after Parks procedure. Recession a group of vertical muscles 5mm or combined with oblique muscles in 3 patients could correct the 20° of vertical head posture, but the improvement of the other two axes was about 5°-10°.One tendon width transposition of all four vertical muscles in 2 cases could correct the 10° of head tilt and 10°-15°of chip up or down. Recession a group of horizontal and vertical muscles can correct 20°-25° of face turn and 20° of vertical head posture.

Conclusions: When head turn with 25°-40°predominates over the vertical and torsional components, recess the horizontal muscles could be effective way in diminishing the abnormal head position on all three axes.When vertical or torsional head posture predominates for the complicated nystagmus, individual designs should be considered.When necessary, reoperations should be needed.