Recession of the superior oblique tendon in A-pattern strabismus

We performed 9 to 12 mm of recession of the superior oblique tendon for A-pattern strabismus in 10 patients. The average preoperative A-pattern measured 29.4 prism dioptres (PD), and the average pattern correction was 29.3 PD. All patients had a residual pattern of 6 PD or less (average 2.3 PD). No patient experienced significant underaction of the superior oblique, and other surgical complications, such as ptosis, Brown's syndrome, and laceration of the vortex vein or superior rectus, did not occur. The procedure corrected 14 to 40 PD of A-pattern. The amount of pattern corrected was correlated with the size of the preoperative A-pattern but not with the total amount of recession done. No significant shift in esodeviation in primary position was noted in the patients who underwent only superior oblique recession. The procedure appears to be of particular value in patients with moderate superior oblique overaction. The advantages of recession of the superior oblique tendon include the potential for reversibility and reoperation, low risk of induced superior oblique palsy, allowance for asymmetric surgery and potential for adjustable suture technique.