Orbital disorders

The orbit is the bony cavity that encloses the globe and accessory organs of the eye, including the ocular muscles, lacrimal glands, nerves, vessels, and retrobulbar adipose tissue. Diseases of the orbital cavity include preseptal cellulitis, orbital cellulitis, orbital compartment syndrome, rhabdomyosarcoma, and lacrimal apparatus disorders. Typical symptoms associated with these diseases include exophthalmos and diplopia. Treatment is based on the underlying disease. Preseptal and orbital cellulitis require prompt initiation of antibiotics. Orbital compartment syndrome (OCS) is an ophthalmic emergency that requires immediate lateral canthotomy and cantholysis to prevent significant vision loss.

See also “Diseases of the lacrimal apparatus,” “Traumatic eye injuries,” and “Graves ophthalmopathy.”

Infections around the orbit are classified as preseptal cellulitis, orbital cellulitis, or orbital abscess (rare); misidentification of the type of infection can lead to inappropriate management and vision loss. ^[1][2][3]

Overview

Preseptal cellulitis and orbital cellulitis can present similarly with unilateral pain, swelling, and redness of the eyelid and periorbital tissues. The primary distinguishing features are red flags of orbital cellulitis, e.g., proptosis, ophthalmoplegia, and reduced visual acuity.

Definition ^[2][4]

• Infection confined to orbital soft tissues anterior to the orbital septum
• Involves the skin of the eyelid and/or the orbicularis oculi muscle

Epidemiology ^[4]

• More common in children than adults
• Peak age group < 5 years old

Etiology ^[4]

• Direct inoculation (most common), e.g., scratch, insect bite, animal bite
• Local spread from adjacent infection, e.g., sinusitis, dacryocystitis
• Hematogenous spread from distant infection, e.g., acute otitis media, pneumonia

Clinical features ^[4][5]

• Unilateral pain, swelling, and redness of the eyelid and periorbital tissues
• Systemic signs of infection, e.g., fever
• No red flags for orbital cellulitis

Reduced visual acuity, RAPD, diplopia, ophthalmoplegia, and/or proptosis are red flags for orbital cellulitis; further investigation is required. ^[2][6]

Diagnostics ^[2][3][4][7]

Preseptal cellulitis is a clinical diagnosis; testing may be performed if there is diagnostic uncertainty, e.g.:

• Laboratory studies: CBC, cultures (e.g., conjunctival, blood)
• Imaging: CT orbits and sinuses with contrast ^[2]
  • Indications
    • Unable to perform a comprehensive eye examination, e.g., because of eyelid edema
    • Red flags for orbital cellulitis
  • Findings: soft tissue thickening anterior to the orbital septum

Differential diagnosis ^[3][4]

• Orbital cellulitis
• Conjunctivitis
• Blepharitis
• Dacryocystitis
• Dacryoadenitis
• Contact dermatitis

Treatment ^[4][8]

• Empiric oral antibiotics are indicated for all patients.
• IV antibiotics and ophthalmology consultation may be indicated in severe cases, e.g., concern for orbital cellulitis, inpatient admission required (see “Disposition”). ^[8]

Oral antibiotics

• Duration: for 10–14 days
• Options for patients without MRSA risk factors
  • Amoxicillin/clavulanic acid ^[8]
  • Cefpodoxime ^[8]
  • Cefdinir ^[8]
  • Adults only: moxifloxacin (off-label) ^[8]
• Options for patients with MRSA risk factors
  • Trimethoprim/sulfamethoxazole (off-label) ^[8]
  • Clindamycin ^[8]
  • Adults only: Doxycycline (off-label) ^[8]

IV antibiotics

• Treatment is similar to that of orbital cellulitis (see “Management” in “Orbital cellulitis”).
• Tailor dosage under ophthalmology guidance.

Complications ^[6]

• Progression to orbital cellulitis
• Spread to CNS, e.g., meningitis, encephalitis (uncommon)

Disposition

Admit patients with any of the following:

• Age < 5 years
• Toxic appearance
• Unable to attend follow-up
• No improvement within 24–48 hours

Orbital cellulitis is a medical emergency; urgent ophthalmology consultation and IV antibiotics are recommended.

Definition ^[2]

• Infection primarily involving but not confined to orbital soft tissues posterior to the orbital septum
• Involves the orbital fat, extraocular muscles, and/or neurovascular tissues

Epidemiology ^[4]

• More common in children than adults
• Highest incidence in winter

Etiology ^[5][9]

• Local spread from adjacent infection, e.g.:
  • Bacterial rhinosinusitis (most common)
  • Odontogenic infection
  • Preseptal cellulitis
  • Dacryocystitis
• Direct inoculation, e.g., orbital trauma, surgery
• Hematogenous spread, e.g., bacteremia, septic emboli

Clinical features ^[4][5][10]

• Localized features: unilateral pain, swelling, and redness of the eyelid and periorbital tissues
• Systemic features of infection: e.g., fever, malaise
• Red flags for orbital cellulitis
  • Proptosis
  • Chemosis
  • Decreased visual acuity
  • Ophthalmoplegia
  • Signs of optic neuropathy (e.g., dyschromatopsia, RAPD)

Diagnostics ^[1][8]

Orbital cellulitis is a clinical diagnosis confirmed with CT imaging.

• Laboratory studies: CBC, inflammatory markers, cultures (e.g., conjunctival, blood)
• Imaging ^[11]
  • CT orbits and sinuses with contrast: to confirm the diagnosis and evaluate for orbital abscess, retained foreign bodies
  • MRI of orbit and sinuses: to rule out suspected cavernous sinus thrombosis or other intracranial complications ^[2][10]

Differential diagnosis ^[3][4]

• Infectious, e.g., preseptal cellulitis, orbital abscess
• Trauma, e.g., retrobulbar hemorrhage, orbital fracture
• Autoimmune disease, e.g., granulomatosis with polyangiitis, sarcoidosis
• Orbital neoplasm
• Cavernous sinus thrombosis

Consider cavernous sinus thrombosis in patients with bilateral eyelid swelling, ptosis, proptosis, ophthalmoplegia, papilledema, or meningismus. ^[11]

Management ^{[1][2][7][11]}

• Consult ophthalmology urgently as soon as orbital cellulitis is suspected.
• Initiate empiric IV antibiotics.
  • Vancomycin ^[8]
  • PLUS one of the following:
    • Ampicillin/sulbactam ^[8]
    • Piperacillin/tazobactam ^[8]
    • Ceftriaxone AND metronidazole
• Consider empiric management of systemic fungal infections (e.g., mucormycosis, aspergillosis) in patients with risk factors for systemic fungal infection.
• Manage orbital abscess if present.
• Provide supportive therapy, e.g.:
  • Nasal decongestant spray for concomitant sinusitis, e.g., oxymetazoline
  • Ophthalmic lubricants if proptosis interferes with eye closure
  • Systemic corticosteroids to reduce local inflammation, only with expert guidance ^[12]

Complications ^[2][11]

• Orbital abscess: a purulent collection in the orbital compartment ^{[1][2][6][13][14]}
  • Usually diagnosed on CT
  • Urgent surgical drainage is often required to prevent intracranial extension, cavernous sinus thrombosis, and/or vision loss.
  • Nonoperative management can be considered in select cases.
• Reduced visual acuity or vision loss
• Intracranial abscess
• Cavernous sinus thrombosis
• Endophthalmitis

Disposition

• Admit all patients for IV antibiotics and assessment by an ophthalmologist.
• Consult additional specialists as needed, e.g.:
  • Otolaryngology: evidence of sinusitis
  • Neurosurgery: evidence of intracranial extension or meningitis
  • Oral maxillofacial surgery: evidence of odontogenic infection
  • Infectious diseases: suspected fungal infection

Definitions ^[15][16][17]

• OCS: an ophthalmic emergency in which orbital compartment pressure exceeds the perfusion pressure of the optic nerve and retina; can cause compressive optic neuropathy
• Orbital compartment pressure: the pressure within the orbit; IOP is used as a surrogate measure of orbital compartment pressure, but they are not synonymous.

OCS can cause irreversible loss of vision within 1–2 hours. ^[15][16]

Etiology ^[15][16]

• Retrobulbar hemorrhage (most common)
  • Trauma (e.g., facial fractures)
  • Craniofacial surgery
• Infection (e.g., orbital cellulitis, orbital abscess)
• Fluid accumulation
  • Prolonged prone position (e.g., spinal surgery)
  • Ocular chemical burns
  • Massive fluid resuscitation
  • Graves ophthalmopathy (late)
• Orbital emphysema (rare)

Clinical features ^[15][16]

• Proptosis
• RAPD
• Firm globe resistant to digital retropulsion
• Eyelid opening resistant to digital pressure
• Eye pain
• Periorbital swelling
• Reduced visual acuity (late finding)
• Dyschromatopsia
• Ophthalmoplegia and/or diplopia

In patients with trauma, avoid palpating the globe or performing tonometry until an open globe injury has been excluded. ^[15]

Diagnostics

OCS is a clinical diagnosis supplemented by tonometry.

• Tonometry: elevated IOP ^[15]
  • IOP > 30 mm Hg: Urgent ophthalmology consult is indicated (urgent orbital decompression may be required).
  • IOP > 40 mm Hg: Urgent lateral canthotomy and cantholysis is indicated.
• Fundoscopy: papilledema, venous congestion, retinal artery pulsation, retinal artery occlusion
• Laboratory studies: CBC, BMP, coagulation panel
• CT orbits: indicated if there is diagnostic uncertainty and/or to evaluate the etiology of OCS ^[16]
• Point-of-care ocular ultrasound: Signs of retrobulbar hemorrhage may be visible. ^[15]

OCS is a clinical diagnosis; do not delay emergent orbital decompression for confirmatory imaging. ^[15]

Treatment ^[15][16]

• Consult ophthalmology as soon as OCS is suspected.
• Perform emergency orbital decompression with lateral canthotomy and cantholysis.
• Definitive surgical management may be required for the underlying cause, e.g., retrobulbar hemorrhage or orbital abscess.
• Provide supportive care (e.g., head of the bed at 45°, pain management, antiemetics, cough suppressants).
• Initiate management of the underlying etiology (e.g., antibiotics for orbital cellulitis).

Prognosis ^[16]

• Treatment within 2 hours of symptom onset: Most patients have final visual acuity > 20/40.
• Treatment after 2 hours of symptom onset: Poor visual acuity outcomes are common.

• Definitions ^[15][18][19]
  • Lateral canthotomy and cantholysis: an emergency surgical procedure used to treat OCS by decompressing the orbit
  • Lateral canthotomy: an incision of the lateral canthus that exposes the lateral canthal tendon
  • Cantholysis: an incision of the lateral canthal tendon used to decompress the orbit
• Indication: clinical diagnosis of OCS ^[15][18][19]
• Contraindication: open globe injury ^[15][18][19]
• Equipment checklist
  • Sterile gown and gloves
  • Surgical mask
  • Topical antiseptic
  • Local anesthetic (e.g., 1–2% lidocaine with epinephrine)
  • 3 mL syringe and 25-gauge or 27-gauge needle
  • Straight hemostat, Kelly clamp, or needle driver
  • Blunt-tipped scissors (e.g., Westcott, Stevens)
  • Toothed forceps
• Procedure ^[18][19][20]
  1. Obtain informed consent.
  2. Perform skin preparation and create a sterile field.
  3. Administer single-point local anesthesia at the lateral canthus.
  4. Apply a clamp horizontally from the lateral canthus to the orbital wall for 1 minute.
  5. Remove the clamp and incise the lateral canthus with blunt-tipped scissors.
  6. Grasp the lower lid with the forceps and lift anteriorly, away from the globe.
  7. Identify the inferior lateral canthal tendon that is located inferoposterior to the lateral canthal fold.
  8. Transect the inferior lateral canthal tendon.
  9. Check that the lower eyelid has released from the globe to ensure adequate inferior cantholysis.
  10. Remeasure the IOP to ensure pressure is < 40 mm Hg.
• Complications
  • Open globe injury
  • Injury to nearby structures (e.g., extraocular muscles, sclera)
  • Ectropion

If IOP remains > 40 mm Hg, ensure the incision of the inferior canthal tendon is complete before incising the superior lateral canthal tendon. ^[15][19]

• Definition: malignant mesenchymal tumor of primitive skeletal muscle cells (rhabdomyoblasts) that have failed to fully differentiate
• Epidemiology
  • Most common soft tissue sarcoma and malignant orbital tumor in children
  • Primarily occurs in the first decade of life.
• Clinical features
  • Frequently in the orbital cavity, but can also be in the head and neck, urogenital region , or extremities
  • Minimally painful, rapidly increasing, gross swelling
  • Orbital rhabdomyosarcoma
    • Growing orbital mass that may be painful and have potential hemorrhage
    • Proptosis or dysconjugate gaze
• Diagnostics
  • Open or core needle biopsy for light microscopy to look for rhabdomyoblasts (confirm the presence of rhabdomyosarcoma)
  • X-ray of the primary site and chest: to determine any bone and lung involvement for staging
  • CT of the primary site and chest: to search for any lung metastases and bone destruction and determine therapeutic response
  • MRI: better to determine specific location of mass and any soft tissue invasion
• Treatment
  • Surgery (complete excision) if a functional and cosmetic result is possible
  • Combination of radiation and chemotherapy following a diagnostic biopsy if complete excision is not feasible
• Prognosis: more favorable for localized tumors of the orbit, and less favorable for metastatic disease