POSTERIOR SUPERIOR OBLIQUE TENECTOMY AT THE SCLERAL INSERTION FOR COLLAPSE OF A-PATTERN STRABISMUS

Purpose: To evaluate:the efficacy of tenectomy of the posterior fibers of the superior-oblique tendon at the scleral insertion to reduce A-p attern deviations with mild-to-moderate superior oblique overaction. M ethods: We retrospectively reviewed 22 consecutive patients with A-pat tern strabismus and mild-to-moderate superior oblique overaction on wh om posterior tenectomy of the superior oblique at the scleral insertio n was performed between January 1988 and August 1994. Nine females and 13 males were included, with an age range of 3 to 36 years (mean 13.0 years). Results: The average preoperative A-pattern for all patients was 18.0 prism diopters (Delta) (10 to 33 Delta), and a collapse of 16 .1 Delta was achieved (P<.000001). The average preoperative A-pattern for esotropic patients was 21.0 Delta with an average correction of 18 .6 Delta. The average preoperative A-pattern for exotropic patients wa s 16.2 Delta with a mean improvement of 14.5 Delta. Twenty patients (9 1%) were postoperatively measured to have 6 Delta or less difference b etween up and downgaze. Follow up ranged from 5.0 to 41.0 months (aver age, 14.0 months). Conclusions: This technique provides the surgeon wi th a predictable partial superior oblique weakening operation that car ries a low risk of induced superior oblique palsy, unwanted cyclotorsi on, or head tilt.