Superior oblique silicone expander for Brown syndrome and superior oblique overaction.

Standard procedures for weakening the superior oblique muscle have been associated with significant complications in the treatment of superior oblique overaction and Brown syndrome. This article presents a new technique for weakening the superior oblique muscle by lengthening the superior oblique tendon. Lengthening is accomplished by a nasal superior oblique tenotomy, and by inserting a segment of medical grade silicone 240 retinal band between the cut ends of the tendon. This technique was performed on 18 patients (30 eyes), 14 (26 eyes) with superior oblique overaction, and four (one eye each) with Brown syndrome. Preoperatively, patients with superior oblique overaction demonstrated A-patterns between 20 prism diopters and 55 delta, and versions of +2 to +4 superior oblique overaction in at least one eye. Postoperatively, the A-pattern and overaction improved in each case, and 13 of the 14 patients had patterns 10 delta or less. Of the four patients with Brown syndrome, three showed marked improvement of elevation in adduction, without consecutive superior oblique palsy. One had no improvement, even after a second procedure, consisting of superior oblique tenectomy; this case probably represents a non-superior oblique restriction (ie, a pseudo-Brown syndrome). Based on these results, it appears that the silicone expander technique is useful in patients with superior oblique overaction and Brown syndrome secondary to tight superior oblique tendon. This technique allows a predetermined degree of tendon separation and a graded weakening of the superior oblique muscle. Furthermore, by controlling the cut ends of the tendon, the procedure is easily reversible and there is ready access to the tendon should reoperation be necessary for residual overaction.