Updated on 

May 16, 2022

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Orbital Bone

What is the Orbital Bone?

The orbital bones join to form the orbit or socket of the eye, where the eyeball rests. 

The orbital structure provides pathways for the eye to connect with the nerves, lacrimal apparatus, adipose tissues, blood vessels, and extraocular muscles. This enables the eye to move and function properly.1 It also protects the eye from injury in case of head trauma. 

However, these bones are delicate and can sustain fractures during a traumatic head injury, which may result from a car accident, impact during contact sport, or during a fistfight.

Orbital Bone Anatomy & Functions

Seven types of bones form the different sections of the orbital structure. These include:

  • Sphenoid 
  • Frontal 
  • Zygomatic 
  • Lacrimal 
  • Ethmoid 
  • Maxilla 
  • Palatine 

Let's look at how these seven orbital bones join to form different parts of the eye socket (orbit):

  • The orbital roof. Formed by the lesser wing of the sphenoid and the frontal bone.2
  • The lateral wall. Formed by the greater wing of the sphenoid bone and the zygomatic bone. 
  • The medial orbital wall. Composed of the lacrimal, ethmoid, maxillary bones, and lesser wing of the sphenoid bones.
  • The orbital floor. Consists of the palatine, maxillary, and zygomatic bones.3

The lateral wall is sturdier than the rest of the orbital walls. Together, the walls function as a barrier against trauma to the eye and anchor muscles that support eye movement. They also serve as a passage for nerves and blood vessels.

Types of Orbital Fractures

An orbital fracture means the bone is cracked or broken. There are three types of orbital fractures: 

1. Orbital Rim Fracture

Orbital rim fractures are caused by trauma to the face, most commonly from a car accident. Considering the force required to cause this fracture, other injuries like facial bone and brain injury may also occur. 

It may also cause damage to other parts of the eye, such as the optic nerve, eye muscles, tear ducts, and sinuses near the eye.

The two types of orbital rim fractures are:

  • Zygomatic bone fracture. Occurs on the lower edge of the eye rim near the cheekbone. 
  • Frontal bone fracture (frontal sinus fracture). Occurs on the upper edge of the eye rim, near the forehead.

2. Direct Orbital Floor Fracture

Direct orbital floor fracture occurs when the rim fracture extends to the socket floor. The fracture is thought to occur due to increased intraorbital pressure. This causes orbital bones to break at their weakest point.

3. Blowout Fracture (Indirect Orbital Floor Fracture)

A blowout fracture occurs when the floor of the eye socket cracks. This causes a small hole that can interfere with eye muscles and other nearby structures. However, the bony rim of the eye is not affected. 

Someone with a blowout fracture may experience difficulty moving their eyes, resulting in double vision. 

This fracture may result from blunt impact with an object larger than the eye socket, such as a hockey puck, a baseball, a hammer, or a fist.

According to experts, about 85% of orbital bone fractures happen while playing a contact sport, doing repairs, at work, or during car crashes.4 Men who work in certain physically demanding jobs or have violent tendencies are at a greater risk of orbital fractures.5

Can Orbital Bone Trauma Affect Vision?

Yes. A severe orbital bone fracture can cause vision issues such as double vision (diplopia), bruising around the affected eye, or difficulty making eye movements.

Other orbital fracture symptoms may include:

  • Bruising due to blood pooling in areas around the eyes
  • Eyeball changes, such as blood in the sclera (white part of the eye)
  • Difficulty with or decreased eye movement
  • Nausea or vomiting 
  • Sunken eyeballs
  • Facial numbness due to nerve damage
  • Eye or cheek pain
  • Swelling due to inflammation of the forehead, cheek, or skin under the eye 

Treatment Options for Orbital Fractures

An injured orbital bone requires immediate examination for any possible fractures. An experienced ophthalmologist can diagnose a bone fracture using X-rays or performing computed tomography (CT) scans.6

In most cases, the fracture can be treated with antibiotics, painkillers, decongestants, and cold compresses to reduce swelling.7 The body eventually heals on its own. However, in the case of a severe fracture, surgery may be the best option.

During recovery, bruises and swelling will heal first (within 7 to 10 days). The fracture may take longer to heal, and the timeline will depend on the severity of the damage.

Your ophthalmologist may advise against sneezing with the mouth closed, blowing your nose, or using a straw for several weeks to avoid further injury.

7 Cited Research Articles
  1. Shumwa C. et al.,“Anatomy, Head and Neck, Orbit Bones,”  National Center for Biotechnology Information (NCBI), 26 Jul. 2021.
  2. Luibil N. et al.,“Anatomy, Head and Neck, Orbit,” National Center for Biotechnology Information (NCBI), 31 Jul. 2021
  3. Turvey T. et al., “Orbital Anatomy for the Surgeon,” National Center for Biotechnology Information (NCBI), 06 Feb.2013
  4. Eye Socket Fracture (Fracture Of The Orbit),” Harvard Medical School, 17 May. 2019
  5. Chiang E. et al.,“Etiology of orbital fractures at a level I trauma center in a large metropolitan city,” Taiwan Journal of Ophthalmology, March 2016
  6. Langen H. et al.,“Conventional x-ray study and computed tomography in the diagnosis of orbital fractures,” National Center for Biotechnology Information (NCBI), May 1998
  7. Orbital Fracture and Traumatic Injury,” Dean McGee Eye Institute
Melody Huang is an optometrist and freelance health writer. Through her writing, Dr. Huang enjoys educating patients on how to lead healthier and happier lives. She also has an interest in Eastern medicine practices and learning about integrative medicine. When she’s not working, Dr. Huang loves reviewing new skin care products, trying interesting food recipes, or hanging with her adopted cats.
Vincent Ayaga is a medical researcher and experienced content writer with a bachelor's degree in Medical Microbiology. His areas of special interest include disease investigation, prevention, and control strategies. Vincent's mission is to create awareness of visual problems and evidence-based solutions shaping the world of ophthalmology. He believes that ophthalmic education offered through research has a greater impact among knowledge seekers.
https://www.visioncenter.org/author/vince/
Author: Vince Ayaga  | UPDATED May 16, 2022
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Medical reviewer: Dr. Melody Huang, O.D.
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Dr. Melody Huang, O.D.
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The information provided on VisionCenter.org should not be used in place of actual information provided by a doctor or a specialist.

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