Small tuck for superior oblique palsy.

Purpose: To investigate the surgical outcomes of small superior oblique (SO) tuck-denoting minimal tendon laxity-in patients with unilateral SO palsy.

Methods: The medical records of consecutive patients treated with ≤6 mm SO tuck from 2000 to 2018 at Kellogg Eye Center, University of Michigan, were reviewed retrospectively. Tendon tucks were performed to a fairly uniform tension in an amount that just eliminated slack in the tendon. Pre- and postoperative motility measurements were compared. Patients were excluded if they had a history of prior strabismus surgery or concurrent vertical rectus or inferior oblique surgery.

Results: A total of 27 cases (14 males) met inclusion criteria. The median age at surgery was 47 years (range 3-74 years). The mean SO tuck (total, both arms of tuck) was 4.9 mm (range, 2-6 mm). After surgery, median hypertropia decreased from 9 to 1 in primary position and from 20 to 4 in the SO field of action (contralateral downgaze). Lateral incomitance (difference in hypertropia between contralateral and ipsilateral gaze) decreased from 10 to 2 (P < 0.001 in each case). Six patients had diplopia in upgaze postoperatively that was not symptomatic enough to require reoperation. Six patients had residual hypertropia requiring additional surgery.

Conclusions: Small SO tuck provided disproportionate correction of hypertropia in the SO field of action and nearly eliminated lateral incomitance without producing unacceptable iatrogenic Brown syndrome. Even in the absence of tendon laxity, SO tuck was a good surgical option for SO palsy in our cohort where there was marked lateral incomitance and the greatest deviation was in the SO field of action.