Bilateral superior oblique temporal tenectomy for the treatment of A-pattern strabismus.

PURPOSE To assess the efficacy of superior oblique temporal tenectomy 6.0 mm from its insertion to treat A-pattern strabismus of all magnitudes. METHODS The clinical records of patients with A-pattern eso- or exotropia associated with bilateral superior oblique overaction who underwent bilateral superior oblique 6.0 mm temporal tenectomy at a single institution over a 17-year period were reviewed retrospectively. Outcome measures were change in the A pattern and correlation with preoperative A pattern. RESULTS A total of 102 patients were included. The mean preoperative A-pattern deviation was 21Δ ± 9Δ, with a postoperative pattern collapse of 18Δ ± 10Δ. Change in A pattern was significantly correlated with the preoperative A pattern (r = 0.70; P <0.001). In patients with an A pattern of ≥25Δ, the preoperative deviation was 31Δ ± 7Δ, with a postoperative pattern collapse of 27Δ ± 9Δ. In 76% of patients with A pattern of <25Δ and in 72% of patients with A pattern ≥25Δ, the A pattern was corrected to <10Δ. The average percentage of A pattern correction was 89% in patients with pattern deviation <25Δ and 86% in patients with pattern deviation ≥25Δ. CONCLUSIONS In our study cohort, bilateral superior oblique temporal tenectomy was an effective and self-adjusting procedure for A-pattern strabismus associated with superior oblique overaction. Larger preoperative A patterns did not show a significant trend toward larger residual postoperative deviations compared with smaller preoperative patterns. A uniform dose of bilateral superior oblique temporal tenectomy collapses A patterns of all magnitudes.