Y-splitting procedure

The Y-splitting procedure divides the lateral rectus muscle tendon lengthwise into two halves that are then reinserted 10-15 mm apart on the sclera in a “Y” configuration. This stabilizes the muscle during co-contraction by preventing the “slipping leash” effect where the tendon slides over the sclera, producing vertical deviations. Y-splitting reduces incomitant vertical deviations that increase with lateral gaze, as seen in Duane syndrome, while preserving some abduction.