Extraocular muscle lacerations.

Five cases of laceration of an extraocular muscle without involvement of the globe or significant involvement of the adnexa occurred after injury with a pencil, mower blade, screen door, and building nail, and at surgery when the surgeon operated on the wrong muscle. The inferior rectus muscle was involved in three cases, the lateral rectus muscle in one, and the medial rectus muscle in one, Traumatic muscle laceration involves the inferior or medial rectus muscles more often than the other muscles. This may occur for two reasons: these muscles are closer to the corneoscleral limbus, and they are more visible during the protective blink with associated upward and usually outward movement of the globe (Bell's phenomenon). When the lacerated muscle could be found, it was repaired either by reinsertion to the sclera or reunion of the severed muscle segments. When the muscle could not be found, a muscle transfer procedure was carried out. Patients with fusion before injury regained fusion in part of the visual field after muscle repair.