Diagnosis and Nonsurgical Management of Strabismus Secondary to Orbital Fracture

Abstract

Introduction

When a large, blunt projectile strikes the eye with sufficient force, the acute rise in pressure within the orbit may result in fracture of the more fragile portions, as the pressure seeks release from the enclosed space. This type of injury may result in a variety of symptoms, including pain, numbness of the cheek, teeth and gums, sinus congestion, nausea, blurred and/or double vision.

Mechanisms of Strabismus

Strabismus secondary to orbital trauma may be due to peripheral cranial nerve palsy, incarceration of extraocular muscle or other orbital soft tissue within the fracture, edema or hemorrhage, or a combination. Actual entrapment of the muscle itself is uncommon, and is usually exclusive to posterior floor fractures

History and External Exam

In spite of the high prevalence of strabismus and diplopia, neither many be the chief ocular complaint of the trauma patient. In addition, not all patients with strabismus secondary to trauma present with a clear history of trauma. The injury may be quite old by the time the patient presents for examination, and the patient may not associate the symptoms with the old injury

Clinical Diagnostic Testing: Motor

All patients with a history of orbital trauma should undergo sequential measurements of ocular alignment and motility in the diagnostic positions of gaze over the first 4 to 6 months. The strabismus that results from trauma is typically incomitant, variable, and complex, and may not readily indicate the mechanism of the disturbance

Clinical Diagnostic Testing: Sensory

Diagnostic testing for the trauma patient who presents with diplopia is straightforward. A red filter placed over the uninvolved eye will assist the patient in identifying the location of the double image and then neutralizing the diplopia with prisms. Not all trauma patients with strabismus present with complaints of diplopia. The patient who is obviously strabismic but has no diplopia should be evaluated for vision loss due to traumatic optic neuropathy or retinal detachment. The patient who is diplopic, but without obvious strabismus should be evaluated for monocular diplopia, media opacity, or retinal contusion.

Nonsurgical Management of Diplopia

The primary objective of nonsurgical treatment of strabismus with resulting diplopia is single binocular vision in primary and in down gaze.

Conclusion

Strabismus and diplopia are common sequelae of orbital trauma. In order to diagnose and manage these cases appropriately, the clinician must take a thorough history, complete a careful external exam, and perform sequential motility exams over a period of 4 to 6 months. These cases can be successfully managed with prisms, occlusion foils, or occlusion until such time as strabismus surgery may be indicated.

• orbital blow-out fractures
• diplopia
• prisms