Traumatic findings can be divided into;

1. Orbital bone fractures

Medial wall fracture: As mentioned earlier, the weakest wall is the medial wall ethmoid part. It may be difficult to realize, so the key to distinguish is adjacent emphysema in the orbit (Fig.1) or displacement of the adipose tissue towards the ethmoid cells. In some severe cases the medial rectus muscle may also be entrapped.

Floor fracture / Blowout fracture (Fig.2): For floor fracture, one should examine the maxillary sinus: air-fluid level or hemorrhage inside the sinus, and sliding of the inferior rectus muscle or the adipose tissue are the alarming signs. Orbital blow out can lead to intraocular hemorrhage as well.

Roof fracture: The frontal sinus is involved. The importance of this fracture is that it can be involved with cerebrospinal fluid leaks and intracranial hematoma. Brain herniation into the orbit is also called blow-in fracture.

Lateral wall fracture: This fracture is mostly the result of high-energy trauma and may involve other facial bones.

Zygomaticomaxillary complex fracture: This type of fracture is also known as tripod fracture. It involves the lateral orbital wall, inferior orbital wall, zygomatic arch, anterior and posterior maxillary sinus walls.

Le Fort type III fracture: It involves the medial and lateral walls as well as the pterygoid plates, nasofrontal suture, maxilla-frontal suture, and the zygomatic arch. It can be thought as a ‘floating face’.

2.Extraocular injuries

Extra and intraconal structures are prone to injury whether a bone fracture and penetrating trauma are involved or not. Hematoma and emphysema are the most common manifestations of intraorbital soft tissue injury. Emphysema can be caused by a foreign body (Fig.3) or nearby bone fracture (see Fig.2) where there could also be bone fragments.

Acute retrobulbar hemorrhage (Fig.4) is an important finding since it can lead to orbital compartment syndrome. In this case, intraorbital pressure increases and the optic neurovascular structures and muscles get compressed, so the patient presents with limited ocular movement, loss of vision or proptosis. Rapid diagnosis and surgical therapy can prevent permanent visual loss.

Extraocular hemorrhage is bleeding in the orbit. It is seen as a hyperdense collection of blood. It can be found intraconally (Fig.5); or outside the muscle cone, mostly adjacent to the periosteum (Fig.6).

Optic nerve injury: The most common causes are nearby fractures, nerve impingement, axonal and feeding vessel injury (Fig.7). 

Orbital apex should be closely evaluated. Traumatic optic neuropathy (TON) can be caused by laceration-compression from a nearby bone fracture or by high speed forces affecting the nerve axons and small vessels. An optic canal fracture and nerve impingement causing TON is called the orbital apex syndrome.

3.Ocular injuries

Hyphema: Normally, the anterior chamber is filled with aqueous humor and seen similar in density to the posterior chamber. Hyphema is the collection of blood in the anterior chamber caused by disruption of vessels nearby. On CT, it is diagnosed by hyperdense image just in front of the lens (Fig.8).

Corneal laceration: The cornea is seen as a convexity just in front of the eyeball. Loss of this can be determined by comparing the pairs (Fig.9).

Lens injury: Normally the lens divides the anterior and posterior chambers. It is kept in position by fibers of zonula. Dislocation is towards  the vitreous humor (Fig.10), and subluxation is the posterior angulation (Fig.11). Lens can rupture after globe rupture as well (Fig.12).

Vitreous hemorrhage: It is seen as increased attenuation in the vitreous body (Fig.13), mostly at the posterior pole due to gravity. It is caused by extravasation of blood. It is important to be aware of other causes such as vitreous detachment, and diabetic retinopathy.

Traumatic detachments: Retinal detachment is seen as a “V” shaped hyperdense fluid at the posterior chamber (Fig.14). The key to differentiate retinal and choroidal detachment is to look at ora serrata and the optic disk. The retinal detachment converges at the optic disk and is limited by the ora serrata anteriorly. But the choroidal detachment diverges at the disk, has a biconvex image and is not limited to the ora serrata.

Foreign bodies: CT is indicated for metallic foreign bodies especially, seen as high density fragments (Fig.15). Glass and wood are usually low density materials on CT, which makes it easy to confuse them for air. Especially hypoattenuating foreign bodies at the corneal surface is hard to determine. At these cases, the key may be to look for hypodense structures of a geometrical shape.

Ruptured globe: Open-globe injury is one of the leading causes of monocular blindness. It can occur after blunt trauma as well, vitreous humor leaking from the thinnest part of the sclera where the ocular muscles attach. On CT, ruptured globe is seen as:

- Asymmetrical globe contour alteration (hence the “flat-tire” sign) (Fig.16)

- Discontinuity and deformity of sclera (Fig.17)

- Intraocular foreign body, air and hematoma (Fig.18)

- Posterior chamber decompression and enlarged anterior chamber as a consequence

Phthisis bulbi is the distortion of the globe due to some of the chronic insults including trauma. It is seen as an atrophic and calcified globe (Fig.19).

Contour change of eye globe is also seen along with some non-traumatic congenital diseases such as coloboma. In this case, auxiliary features such as retrobulbar fat stranding, hematoma, foreign body and emphysema can guide in the differential diagnosis.

Enucleation: Traumatic enucleation of the eye globe is a catastrophic result of penetrating injury that mostly results in complete surgical enucleation (Fig.20)