Surgical treatment of the upshoot and downshoot in Duanes' retraction syndrome.

The upshoot and downshoot that occurs when the eye is rotated into the adducted position in Duanes' retraction syndrome is believed to be related to a taut or leash effect from the lateral rectus muscle. When the eye is adducted, the lateral rectus muscle is believed to "slip" over the globe, producing this abnormal movement. Five patients with Duanes' retraction syndrome demonstrated this finding and underwent a splitting of the lateral rectus into a Y configuration. All five patients demonstrated a marked decrease in the up- or downshoot after surgery.