Nasal insertion of the superior oblique tendon presenting as Brown syndrome

Anomalous ocular muscle insertions are a rare cause of ocular motility disturbances.We report the clinical presentation and the intraoperative findings of two cases with an abnormally nasally inserted superior oblique tendons presenting with a Brown syndrome-like clinical picture.Case no 1 was a 5-year-old girl presenting with a chin up position. There was bilateral limitation of elevation in adduction, -4 on the right side and -3 on the left side with +1 downshoot on adduction on either side Patient was orthotropic in down-gaze with small V-pattern exotropia. Case no 2 was a 4-year-old boy presenting with an esotropia of 35Δ that was partially corrected with his spectacles to 20Δ. Ductions showed -4 defective elevation in adduction of the right eye. Surgical exploration in both cases revealed abnormal nasal insertion of the superior oblique tendons. The line of insertion had a convexity facing superonasally. The posterior fibers were inserted 7-8 mm posterior and just nasal to the nasal border of the superior rectus insertion, while the anterior fibers were shorter and inserted 5 mm nasal and 4 mm posterior to the nasal edge of superior rectus insertion. In both cases, there was an improvement in the elevation on adduction after superior oblique lengthening.Abnormal nasal insertion of the superior oblique muscle enhances the depressor effect of the muscle and can create a Brown-like picture.