Orbital Floor Fracture (Blow-out Fracture)

An orbital floor fracture, also called a blow-out fracture, is a break in the thin bone in the floor of the eye socket (orbit). This injury results from blunt force to the eye or the area around it and is among the most common facial fractures in children and adolescents.

How does a blow-out fracture happen?

When an object, for example a ball, a fist, an elbow or a branch, strikes the eye or the eye socket with force, the pressure inside the orbit rises abruptly. Because the floor and the inner wall of the orbit are particularly thin, these bones give way and break. Soft tissue (muscle, fatty tissue) can slip into the fracture gap and become trapped there.

A particular point in children: in children the bones are more flexible. What is known as a "trapdoor fracture" can occur: a flap of bone opens, tissue slips in, and the flap snaps shut again, like a trapdoor. This injury is an emergency, because trapped muscle is quickly damaged.

Symptoms

Typical signs of an orbital floor fracture are:

• Swelling and bruising around the eye
• Double vision (particularly on looking up or down)
• Restricted eye movement
• Pain on eye movement
• Numbness of the cheek, nose or upper teeth
• Sunken eye (enophthalmos), often only visible once the swelling subsides

With a trapdoor fracture in children there is frequently severe pain on eye movement, nausea and vomiting, sometimes without any outwardly striking swelling or bruising. These symptoms can be mistaken for concussion.

Diagnosis

The diagnosis is made through clinical examination and imaging:

• Clinical examination: the ophthalmologist checks visual acuity, eye movement, pupil reaction and eye position.
• CT (computed tomography): thin-slice CT images of the orbit are the gold standard and show the position, size and type of the fracture as well as any trapped tissue.
• MRI: can be used as a radiation-free alternative, particularly in children.

Treatment

Simple fracture (without entrapment)

Most uncomplicated fractures heal without surgery. Treatment includes:

• Cooling with ice packs in the first few days
• Decongestant nasal drops
• No nose blowing: the build-up of pressure can force air from the sinuses into the orbit
• Where appropriate, a short course of steroids to reduce swelling and scarring
• Antibiotics where there is an accompanying sinus infection
• Pain medication

Double vision often improves within days to weeks, as soon as the swelling subsides.

Surgical treatment

Surgery is necessary in the case of:

• Trapdoor fractures with trapped tissue: this is an emergency. Surgery should take place within 24 to 48 hours in order to free the trapped tissue (usually an eye muscle) and avoid permanent damage.
• Persistent double vision: where double vision does not improve after several weeks
• Marked enophthalmos: where the eye is clearly sunken

During surgery the fracture is exposed, trapped tissue is released and the defect in the bone is covered with an implant (titanium or synthetic material).

Possible long-term consequences

Most orbital floor fractures heal well. In some cases, however, the following can persist:

• Permanent double vision (which can be treated with prism glasses or eye muscle surgery where appropriate)
• A sunken eye
• Numbness in the area of the cheek

Prevention

In sports with an increased risk of injury (ball sports, martial arts, ice hockey), suitable protective eyewear offers the best protection against orbital fractures.

Our advice

After a blow to the eye or the eye socket, particularly where double vision, restricted movement or nausea occur, an ophthalmologist or emergency department should be consulted without delay. In children with pain and vomiting after a facial injury, a trapdoor fracture must always be considered, since it requires prompt surgical treatment.

Dr. Stefan Langenegger

Treating Ophthalmologist

044 442 04 05