ABSTRACT
Surgical management of SOP depends on the laterality, the degree of superior oblique muscle underaciton and type of the muscle sequelae that has developed. It is generally believed that a V-pattern exotropia on up-gaze is usually associated with IOOA & can be treated with IO weakening procedures. However in the case of significant SO underaction, particularly if there is a V-pattern esotropia on down gaze a strengthening of SO muscle is indicated. Insuperable cyclotorsion also requires strengthening of the SO muscle. Most authors recommend that up to 15-20 PD hypertropia in primary position can often be successfully corrected by recession of the inferior oblique, while any deviation exceeding 20 PD requires additional recession of the ipsilateral superior rectus or contralateral inferior rectus depending on the nature of the muscle sequelae1. The role of SO tuck in managment of superior oblique palsy remains controversial. In several reports no correlation could be found between the size of the tuck and the amount of deviation corrected3,5. It has been suggested that other factors such as laxity of SO tendon and the amount of preoperative deviation are also important in influencing the outcome of SO tuck procedure. Simons et al in their series reported a 50% lower reoperation rate with SO tuck however they had a high rate of surgical Brown syndrome (61%),which in their opinion could be reduced with adjustment of the magnitude of SO tuck based on SO tendon laxity5. In contrary to their opinion, many surgeons feel that the complications of SO tuck outweight the advantages. Infact recent treatment protocols warrant SO tuck only in the case of marked SO tendon laxity during exaggerated SO tendon traction test2,4. This study shows our experience of treating superior oblique palsy with various IO weakening and vertical rectus muscle procedures. A single corrective surgery was successful in 96 patients (84%) while we had good results in 97 patients (85%). These figures improved to 105(92%) and 106(93%) after the second surgery, which are comparable to the results of previous studies1. According to the mentioned results we recommend IO weakening procedures combined with a vertical rectus muscle surgery (in more severe cases) for treating SO palsy. These procedures have comparable results to the SO tuck, need less expertise, are more predictable and have lower complication rates. In our experience up to 25 hyperdeviation in the primary position could be treated with ATIO alone and for any extra-deviation we recommend rectus muscle surgeries depending on the nature of the deviation. In our opinion superior oblique surgery is indicated only if 10 excyclotorsion is present, in which a Harada-Ito procedure is probably preferable.
