From the Guidelines
Orbital cellulitis involves inflammation of the tissues within the eye socket (orbit) behind the orbital septum, primarily affecting the orbital fat, extraocular muscles, and connective tissues surrounding the eye. The infection can also spread to involve the periosteum of the orbital bones, the optic nerve sheath, and in severe cases, can extend to form a subperiosteal or orbital abscess 1. This condition typically develops as a complication of sinusitis, particularly from the ethmoid sinuses, when bacteria breach the thin bone separating the sinuses from the orbit 1. Key tissues involved in orbital cellulitis include:
- Orbital fat
- Extraocular muscles
- Connective tissues surrounding the eye
- Periosteum of the orbital bones
- Optic nerve sheath The infection causes swelling, redness, pain, and potentially impaired eye movement and vision. Common causative organisms include Staphylococcus aureus, Streptococcus species, and anaerobic bacteria. Treatment requires prompt administration of intravenous antibiotics, with surgical drainage indicated for abscesses or if medical therapy fails 1. Orbital cellulitis is a medical emergency that requires immediate attention to prevent serious complications including vision loss, cavernous sinus thrombosis, meningitis, or brain abscess 1.
From the Research
Tissues Involved in Orbital Cellulitis
The tissues involved in orbital cellulitis include those located posterior to the orbital septum within the bony orbit 2. This can encompass various orbital tissues, but the specific tissues involved are not exhaustively listed in the provided studies.
Commonly Affected Tissues
- Eyelids: Orbital cellulitis often manifests with erythema and edema of the eyelids 2.
- Orbital septum: The infection is generally limited to the tissues posterior to the orbital septum 2.
- Paranasal sinuses: Many cases of orbital cellulitis originate from sinus infections 2, 3, 4.
- Subperiosteal tissue: Subperiosteal abscesses are a common complication of orbital cellulitis 5, 3, 4.
- Intracranial structures: In severe cases, orbital cellulitis can extend to intracranial structures, such as the cavernous sinus 3, 6.