Infections may involve the tissues around or within the eye. These infections are most common among children.

Preseptal cellulitis

Preseptal cellulitis (periorbital cellulitis) is infection of the eyelid and skin and tissues around the front of the eye.

Preseptal cellulitis usually is caused by spread of an infection of the face or eyelid, an infected insect or animal bite, conjunctivitis, a chalazion, or sinusitis.

Tissues around the eye become swollen, warm, tender, and usually red. Sometimes the eye is so swollen that it cannot be easily opened. However, once the eye is opened, vision is not impaired. A fever may develop.

Doctors can often diagnose preseptal cellulitis by the person's symptoms, but sometimes a potentially more serious infection, orbital cellulitis, may also be a possible diagnosis. If so, computed tomography (CT) or magnetic resonance imaging (MRI) is done.

Treatment consists of antibiotics (for example, amoxicillin with clavulanate). If people are very ill or cannot take pills, hospitalization is recommended. People should be monitored closely by an ophthalmologist.

Orbital Cellulitis

Orbital cellulitis (postseptal cellulitis) is infection affecting the tissue within the orbit and around and behind the eye.

• Infection can spread to the orbit from sources such as the sinuses around the nose.
• Pain, swelling, red eye, impaired vision, and impaired eye movements can develop.
• Usually, computed tomography (CT) or magnetic resonance imaging (MRI) is done.
• Antibiotics are given by vein (intravenously), and the person is admitted to the hospital.

Orbital cellulitis usually is caused by spread of an infection to the orbit from the sinuses around the nose (nasal sinuses) but can also be spread from infection of the teeth or bloodstream. An animal or insect bite or another wound can also spread infection and lead to orbital cellulitis.

Without adequate treatment, orbital cellulitis can lead to blindness. Infection can spread to the brain and spinal cord, or blood clots can form and spread from the veins around the eye to involve a large vein at the base of the brain (the cavernous sinus) and result in a serious disorder called cavernous sinus thrombosis (see Eye Socket Disorders: Cavernous Sinus Thrombosis).

Symptoms

Symptoms include pain, a bulging eye, red eye, reduced eye movement, double vision, pain with eye movement, swollen eyelids, and fever. The eyeball is swollen. Vision may be impaired.

Diagnosis

Doctors can usually recognize orbital cellulitis without diagnostic tests. However, CT or MRI usually is done to confirm the diagnosis. Also, determining the cause may require further assessment, including examination of the teeth and mouth and CT or MRI of the nasal sinuses. Often, doctors obtain samples from the nasal sinuses as well as blood samples and send them to a laboratory for testing. The samples are cultured (to grow microorganisms) to determine what bacteria are causing the infection, which areas are infected, and which antibiotic should be used. A person with orbital cellulitis is examined by an ophthalmologist.

Treatment

People are admitted to the hospital. Antibiotics are started as soon as possible, before the results of the laboratory testing are known. Antibiotics are usually given by vein initially. A few days later, once people recover, antibiotics are given by mouth. The antibiotic used at first may be changed if the culture results suggest that another antibiotic would be more effective. Sometimes surgery is needed when vision is impaired, to drain a collection of pus (abscess) or an infected nasal sinus, to remove a foreign body or pus, or to help treat the infection if antibiotics alone are not effective.

Last full review/revision July 2012 by James Garrity, MD