An Approach to Some Aspects of Strabismus from Ocular and Orbital Trauma

Strabismus caused by ocular or orbital trauma can be the result of localized acute soft tissue swelling or may follow orbital fractures, partial or complete loss of extraocular muscle (EOM) and/or cranial nerve function, or damage to surrounding tissues causing mechanical restriction. The strabismus is frequently incomitant and can be difficult, if not impossible to completely correct. The resulting diplopia can affect the individual's ability to function at work, in sports and in common tasks of daily living like driving. The preoperative evaluation should include an assessment of the degree of limitation, muscle function and the condition of the surrounding tissue. In most cases, high resolution computed tomography and/or surface coil dynamic magnetic resonance imaging are required to determine the extent and nature of suspected bony or EOM injury, as well as muscle contractility. If the scan reveals an intact but paretic muscle or only minor muscle injury, surgical intervention is based on the degree of muscle recovery 6 months after the initial insult. If a rectus muscle has been lacerated, and the proximal stump is functional, retrieval should be attempted, either by a direct conjunctival approach if located anteriorly, or by an anterior medial orbitotomy if located deep in the orbit. If a damaged muscle cannot be found, recovered or repaired at any time, then muscle transposition should be considered. If multiple muscles are damaged or scar tissue is excessive, a tether procedure may be indicated. This paper will present an approach to some aspects of strabismus in this setting.