An approach to some aspects of strabismus from ocular and orbital trauma

Abstract

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.

A Rare Case Report: Traumatic Isolated Medial Rectus Dehiscence and its Surgical Outcome

“…It was easily identified and successfully sutured with good outcome.Accurate diagnosis and prompt intervention resulted in good surgical outcome. Optimal intervention generally involves an initial attempt at targeted exploration with attempted recovery and/or repair of the damaged, transected, or lost extraocular muscle which may be performed early, immediately following the injury [1][2][3].…”

Isolated Rupture of the Superior Rectus Muscle following Blunt Trauma – A Case Report

“…Parks originally described the difference between lost and slipped muscles, "lost" muscles being those in which the muscle and capsule are completely detached from the sclera, while a slipped muscle is one that retracts within its sheath, while the capsule remains attached to the sclera [6,10]. Rectus muscles that are traumatically injured are usually easier to fi nd than those that are "lost" or have "slipped" following elective muscle surgery [4][5][6]8] as the injured muscle often retains some fascial attachments and not all muscle fi bers An adjustable suture is preferred to reattach a "lost" muscle for a few reasons [5]. Firstly if there is a delay between injury and repair the ipsilateral antagonist may become contracted, exacerbating the duction defi cit [3,4].…”

“…Rectus muscles that are traumatically injured are usually easier to fi nd than those that are "lost" or have "slipped" following elective muscle surgery [4][5][6]8] as the injured muscle often retains some fascial attachments and not all muscle fi bers An adjustable suture is preferred to reattach a "lost" muscle for a few reasons [5]. Firstly if there is a delay between injury and repair the ipsilateral antagonist may become contracted, exacerbating the duction defi cit [3,4]. In this case the muscle was found at the second procedure so some inferior rectus contraction may have occurred already.…”

“…Her LHoT was coupled with an inability to initiate any saccadic movement in upgaze. Forced duction test showed no restriction to supraduction and force generation testing indicated a negligible restriction to inferior movement when the patient was requested to supraduct the eye [4]. Versions can be noted in fi gure 1.…”

“…Isolated traumatic injury to an extraocular muscle is rare [1]. Even rarer is an isolated rupture of a SRM in the absence of a globe injury or orbital fractures [2][3][4]. We report a case of a muscle belly rupture/laceration as a result of a combination of blunt/sharp trauma from the bizarre mechanism of injury where a USB drive entered the orbit during a motor vehicle accident.…”