Transection of the inferior rectus muscle

A systematic approach to CT evaluation of orbital trauma

Computed tomography (CT) is widely used in the initial evaluation of patients with craniofacial trauma. Due to anatomical proximity, craniofacial trauma often involves concomitant injury to the eye and orbit. These injuries may have devastating consequences to vision, ocular motility, and cosmesis. CT imaging provides a rapid and detailed evaluation of bony structures and soft tissues of the orbit, is sensitive in detection of orbital foreign bodies, and often guides clinical and surgical management decisions in orbital trauma. For this reason, radiologists should be prepared to rapidly recognize common orbital fracture patterns, accurately describe soft tissue injuries of the orbit, detect and localize retained foreign bodies within the globe and orbit, and recognize abnormalities of the contents and integrity of the globe. In this review, we present a systematic approach to assist radiologists in the rapid evaluation of orbital trauma using the "BALPINE" mnemonic-bones, anterior chamber, lens, posterior globe structures, intraconal orbit, neurovascular structures, and extraocular muscles/extraconal orbit. Using this approach, we describe common traumatic findings within each of these spaces, and present common postsurgical appearances that can mimic findings of acute trauma.

Inferior rectus rupture following blowout fracture

BACKGROUND

Extra-ocular muscle rupture is uncommon, usually seen after penetrating trauma or surgery. It is a very rare cause of diplopia following blunt orbital trauma.

METHODS

A patient who presented with no inferior rectus function after blunt orbital trauma is described.

RESULTS

Computed tomography (CT) scans demonstrated a large orbital floor fracture and suggested that the inferior rectus muscle was ruptured. This was confirmed at operation. Despite anatomical repair, there was no postoperative improvement in ocular motility.

CONCLUSIONS

Traumatic rupture of the inferior rectus is rare. Forced duction and force generation testing and CT are important in diagnosing ocular motility defects following orbital trauma.