Achieving success with the silicone expander for overacting superior obliques

Purpose: To report the results of and complications with silicone expander surgery for the overacting superior oblique. Methods: A total of 26 patients with bilateral overaction of the superior oblique and A-pattern strabismus and 5 patients with unilateral overacting superior oblique secondary to inferior oblique palsy were treated with a 7 mm silicone expander. Care was taken not to enter the sub-Tenon's space. Results: The group that underwent bilateral superior oblique surgery had an average preoperative pattern of 37.42 diopters (D) and an average correction of 35.37 D. Three patients had a severe unilateral postoperative inflammatory incident that was successfully treated with oral and topical corticosteroids. One of these patient developed Brown's syndrome. Another patient, who had no postoperative inflammatory incident, also developed Brown's syndrome. In these 4 patients, the sub-Tenon's space was inadvertently entered during surgery. Conclusion: The silicone expander surgery has a very high success rate in treating the A-pattern associated with the bilateral overacting superior oblique. This procedure also works well for the unilateral superior oblique that overacts owing to an inferior oblique palsy. No cyclotorsion symptoms occurred after this surgery. However, 4 patients had complications because the sub-Tenon's space was exposed during surgery. With this procedure, there is a learning curve to obtain the skill not to enter the sub-Tenon's space.