What is orbital cellulitis?
Orbital cellulitis, also known as postseptal cellulitis, is an infection of the soft tissues and fat located in the orbital structure behind the eye. The infection may begin suddenly or be the result of a separate infection.
The condition is not contagious and mostly affects children, though it can affect adults as well.
Immediate treatment is required for orbital cellulitis — it can cause blindness and lead to other life-threatening conditions if it’s not cared for promptly and properly.
Orbital cellulitis symptoms, such as pain, discharge or double vision, present the same way in both adults and children. Symptoms of the condition can include the following:
Discharge in the infected eye
Redness and inflammation
Impaired vision or vision loss
Nasal tenderness or discharge
Difficulty opening or moving the eye
Cases of orbital cellulitis are frequently associated with bacterial sinus infections, so it is important to note if you currently have one (or very recently had one) when identifying other symptoms.
Causes of orbital cellulitis
The most common cause of orbital cellulitis is a bacterial infection. According to research, 86-98% of these infections are caused by untreated bacterial sinus infections that have spread to the orbital spectrum.
Two of the most common bacterial strains that may cause orbital cellulitis are Staphylococcus aureus and Streptococcus pneumoniae.
Although bacterial sinus infections cause the majority of orbital cellulitis cases, bacterial infections can in fact spread from any part of the body and impact the eye.
Orbital cellulitis can also be caused by other conditions and factors, including:
Infections in the teeth, face or middle ear
Orbital trauma such as an orbital fracture
Foreign object entering or becoming trapped in the eye
Animal or insect bites in or around the eye
Untreated preseptal cellulitis
Asthma or other immunodeficiency
Orbital cellulitis is initially diagnosed by a visual examination performed by an eye doctor. Diagnostic testing is performed to confirm the condition is present (as opposed to another infection), as well as to determine which bacteria caused an infection to develop.
Diagnostic testing to confirm orbital cellulitis may include the following:
Visual examination of the eyes, head and nose
MRI or CT scan to further examine the eyes, head and nose
Nasal and eye discharge cultures
Regardless of the results of the diagnostic testing, treatment should begin immediately if a doctor believes orbital cellulitis or another serious infection is present.
Because orbital cellulitis occurs behind the eye, there is a risk that it may spread to the brain or central nervous system if it is not treated promptly.
Treatment for orbital cellulitis may include intravenous (IV) antibiotics or surgery, depending on the severity of the condition. Each of these treatments involve a visit to the hospital.
Intravenous (IV) antibiotics
Broad-spectrum antibiotics are administered in a continuous dose through an IV as the first step in treating orbital cellulitis, as well as any other bacterial infections that may be present.
If the affected eye doesn’t respond, or if diagnostic tests reveal another infection, a different type of antibiotic may then be used.
You may be prescribed oral antibiotics to take for 2 to 3 weeks following IV treatment, to make sure orbital cellulitis heals completely.
If the infection does not respond to antibiotics, or if it gets worse, surgery may be required for treatment. Surgery is generally also required if orbital cellulitis was caused by a foreign object that needs to be removed from the eye.
During surgery for orbital cellulitis, a doctor will drain fluid in the infected eye as well as from the sinuses. An abscess may form with the infection — should this occur, the abscess will also be drained during surgery.
Not every case of orbital cellulitis requires surgery. Children who have the condition, for instance, are less likely to need surgery than adults.
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Complications from orbital cellulitis
If you or your child experiences symptoms of orbital cellulitis — especially if a sinus infection is also present — contact an eye doctor immediately.
When orbital cellulitis is not treated promptly, serious complications can arise that affect both vision and other parts of the body. Some conditions that may develop due to untreated orbital cellulitis include:
Vision loss (partial or complete)
Intracranial abscess (a buildup of pus in the brain)
Cavernous sinus thrombosis (a blood clot which forms at the brain’s base)
Orbital cellulitis vs. preseptal cellulitis
Preseptal cellulitis, also called periorbital cellulitis, is an infection of the eyelid and the surrounding tissues anterior to (in front of) the orbital spectrum. It is different from orbital cellulitis because of the location in which it takes place, as well as its severity — among other key factors.
The table below provides a broad comparison of orbital cellulitis and preseptal cellulitis:
|Orbital cellulitis (postseptal cellulitis)||Preseptal cellulitis (periorbital cellulitis)|
|Severity||Extremely severe||Not severe if treated promptly|
|Location of infection||Posterior to (behind) the orbital spectrum||Anterior to (in front of) the orbital spectrum|
|Common symptoms||Eyelid swelling, severe eye pain, difficulty moving eye, impaired vision, fever||Severe eyelid swelling, tenderness, redness, fever may occur|
|Common causes||Bacterial sinus infection or other bacterial infection||Insect or animal bite, injury, chalazion, conjunctivitis|
|Treatment||IV antibiotics or surgery, may be followed with oral antibiotics||Oral antibiotics|
Generally, preseptal cellulitis is less serious than orbital cellulitis, and is often not severe at all when it is treated promptly. If preseptal cellulitis is not treated quickly, however, it can potentially lead to orbital cellulitis.
Orbital cellulitis and overall eye health
Orbital cellulitis can affect anyone, but it is most common in children. Severe eyelid swelling and pain — especially if accompanied by a fever or headache — are major indicators of conditions such as orbital cellulitis.
As with many eye infections, treatment for orbital cellulitis is required as soon as possible to prevent further complications.
When it comes to eye health, do not hesitate to contact an eye doctor for an evaluation regarding a major concern for you or your child.
Annual eye exams are also critical in caring for your eyes, as they are the best way to identify new or developing eye conditions, as well as general adjustments in vision.
Page published in February 2021
Page updated in February 2021