Purpose: Weakening of both horizontal rectus muscles is performed for patients with Duane syndrome and significant misinnervation of the lateral rectus (LR) muscle resulting in strabismus, limitation to ocular rotations, and globe retraction. In patients with severe up-/downshoots, a Y-splitting of the LR is often recommended. The purpose of this study was to evaluate the efficacy of isolated unilateral LR recession-Y splitting in exo-Duane patients with limitation to adduction and up-/downshoots.
