Single horizontal rectus muscle vertical augmented transposition with posterior fixation suture in management of monocular elevation deficiency.

We describe successful management of three cases of acquired monocular elevation deficiency (MED) with superior transposition of the lateral rectus augmented with a posterior fixation suture with or without simultaneous inferior rectus muscle weakening. In each case, the lateral rectus muscle was transposed superiorly to the superior rectus muscle along the spiral of Tillaux, with maintained distance between the original lateral rectus muscle poles and the limbus. Augmentation was achieved with a posterior fixation suture 8 mm posterior to the muscles' insertion. At the time of lateral rectus transposition, simultaneous inferior rectus recession by 5.5 mm was performed in case 1 whereas simultaneous botulinum toxin injection was performed in case 3. With regards to all three cases, the mean age was 32 years [10-46 years] and the mean follow-up period was 10 months. The mean hypotropia was reduced from 35 prism diopters (PD) (range: 20 to 60 PD) to 4.67 PD (range: 0 to 14 PD) with a mean correction of 32.57 ± 9.34 PD after 9 months. In our experience, full-tendon-width transposition of the lateral rectus to the superior rectus with posterior fixation suture corrects primary position hypotropia in MED and does not always require simultaneous inferior rectus recession. When transposing the lateral rectus muscle along the spiral of Tillaux, the measured distance of the original muscle insertion point to the limbus must be maintained in order to prevent recession of the muscle.