Anterior segment ischemia occurred in a 66-year-old patient following recession of one medial rectus muscle combined with lateral rectus muscle union to the vertical rectus muscles (Jensen procedure). The mechanism of this complication is explained as inadvertent strangulation of the anterior ciliary arteries during tying of the split lateral rectus to the temporal aspects of the vertical rectus muscles. Special efforts to preserve the integrity of anterior ciliary arteries in those portions of the vertical rectus muscles not involved in the muscle union should be made to avoid this complication.