Orbital cellulitis

Orbital cellulitis


Infective process involving ocular adnexal structures posterior to the orbital septum.

  • Does not involve the globe itself
  • M/C cause of unilateral proptosis in children


  • Infection of the teeth, middle ear, or face
    • Bacterial rhinosinusitis (M/C cause)
  • Dacryocystitis
  • Orbital trauma with fracture/foreign body
  • Ophthalmic surgery
    • Such as strabismus surgery, blepharoplasty, radial keratotomy and retinal surgery
  • Peribulbar anesthesia
  • Infected mucocele eroding into the orbit
  • Immunodeficiency

Common bacterial causes:

  • Staphylococcus aureus
  • Streptococci 

Rare bacterial causes:

  • Non-spore-forming anaerobesAeromonas hydrophila, Pseudomonas aeruginosa, and Eikenella corrodens 
  • MycobacteriaMycobacterium tuberculosis

Fungal pathogens (invasive orbital cellulitis) (also common in immunocompromised states):

  • Mucorales (causes mucormycosis) (also affects cases with diabetic ketoacidosis & renal acidosis)
  • Aspergillus (cause life-threatening invasive orbital infections) (common in cases with severe neutropenia or other immune deficiencies like HIV)

Clinical features

  • Ophthalmoplegia with diplopia
  • Pain with eye movement
  • Proptosis
Left sided periorbital swelling and proptosis. | Goodyear, P. W. A., Firth, A. L., Strachan, D. R., & Dudley, M. (2004). Periorbital swelling: the important distinction between allergy and infection. Emergency Medicine Journal, 21(2), 240 LP-242. https://doi.org/10.1136/emj.2002.004051

Other features:

  • Eyelid swelling with/without erythema (also found in preseptal cellulitis)

Case studies:


  • Subperiosteal abscess (15-59% cases)
  • Orbital abscess (24% cases)
  • Vision loss (3-11% cases)
  • Extraorbital extension:
    • Cavernous sinus thrombophlebitis
    • Brain abscess
Preseptal and Orbital Cellulitis

Pre-antibiotic era outcomes:

  • Death (17% cases)
  • Permanent blindness (20% cases)

Case study:

External photograph of a 21-year-old female who was diagnosed with right-sided orbital abscess which did not undergo drainage. Chronically untreated orbital abscess resulted in erosion of her orbital wall and intracranial extension | Chaudhry, I. A., Al-Rashed, W., & Arat, Y. O. (2012). The hot orbit: orbital cellulitis. Middle East African Journal of Ophthalmology, 19(1), 34–42. https://doi.org/10.4103/0974-9233.92114


Approach to the evaluation of the swollen red eyelid. (CT = computed tomography; IV = intravenous.) | Carlisle, R. T., & Digiovanni, J. (2015). Differential Diagnosis of the Swollen Red Eyelid. American Family Physician, 92(2), 106–112.

CT scan:

Investigation of choice
  • Inflammation of extraocular muscles
  • Fat stranding
  • Anterior displacement of globe


Orbital cellulitis related to mucormycosis (A–C) and bacterial infection (D–F). A, Axial T1-weighted fat-suppressed postcontrast image shows an opacified right maxillary sinus and extensive enhancement throughout the infratemporal fossa tissues, involving the pterygoid muscles (arrow). B, Axial exponential ADC image shows low intensity throughout these tissues (arrow), indicating relatively increased ADC, best appreciated by comparison with the contralateral side. The area of restricted diffusion behind the right maxillary sinus represents abscess. C, Axial exponential ADC image through the orbit shows restricted diffusion within the infarcted posterior right optic nerve (arrow). D, Axial T1-weighted fat-suppressed postcontrast image shows intense enhancement within the periorbital soft tissue (arrow). E, Axial T2-weighted image shows moderate hyperintensity relative to extraocular muscle. F, Axial exponential ADC image slightly lower shows increased ADC throughout the region of nonspecific enhancement (arrow). Restricted diffusion is seen within an abscess (a), which corresponds with a nonenhancing T1 hypointense area. Diffusion is not restricted within the tissues immediately surrounding the focal abscess. G, Axial T1-weighted fat-suppressed postcontrast image shows no enhancement within an abscess (a), with marked enhancement in the area of cellulitis. | Kapur, R., Sepahdari, A. R., Mafee, M. F., Putterman, A. M., Aakalu, V., Wendel, L. J. A., & Setabutr, P. (2009). MR Imaging of Orbital Inflammatory Syndrome, Orbital Cellulitis, and Orbital Lymphoid Lesions: The Role of Diffusion-Weighted Imaging. American Journal of Neuroradiology, 30(1), 64 LP-70. https://doi.org/10.3174/ajnr.A1315

Differential diagnosis:

  • Inflammatory causes (thyroid eye disease, idiopathic orbital inflammatory syndrome, sarcoidosis, granulomatosis with polyangiitis)
  • Infectious causes (subperiosteal abscess)
  • Neoplastic, benign and malignant (dermoid cyst, capillary hemangioma, rhabdomyosarcoma, optic nerve glioma, lymphangioma, neurofibroma, leukemia)
  • Trauma (orbital fracture, retrobulbar hemorrhage, orbital foreign body, carotid cavernous fistula)
  • Malformation (congenital, vascular)
(A) Anatomy of orbit and eyelid with associated pathologic processes by location. (B) External anatomy of the eyelid. | Carlisle, R. T., & Digiovanni, J. (2015). Differential Diagnosis of the Swollen Red Eyelid. American Family Physician, 92(2), 106–112.


Clinical management of orbital cellulitis |

IV antibiotics:

  • Vacnomycin (MRSA coverage) + Ceftriaxone/cefotaxime/ampicillin-sulbactam/piperacillin-tazobactam ± metronidazole (anaerobic coverage)
  • In case of allergy to penicillins and/or cephalosporins:
    • Vacnomycin (MRSA coverage) + ciprofloxacin/levofloxacin
  • Oral antibiotics:
  • Clindamycin
  • Clindamycin/trimethoprim-sulfamethoxazole + amoxicillin/amoxicillin-clavulanic/cefpodoxime/cefdinir

Surgical management:

  • Indications:
    • Intracranial extension of the infection
    • Poor/failure to respond to antibiotic therapy (confimed in CT after 48 hours)
    • Worsening visual acuity/pupillary changes
    • Large abscess (> 10 mm)
External photograph of a 27-year-old female patient who presented with left periocular edema, pain and decreased vision after a fall several days earlier. Imaging studies confirmed evidence of sinusitis and orbital fracture. Ultrasonography of her left eye revealed a stretched optic nerve along with compression on the eye. During exploration, an abscess was drained from the left lower eyelid that was connected to her maxillary sinus | Chaudhry, I. A., Al-Rashed, W., & Arat, Y. O. (2012). The hot orbit: orbital cellulitis. Middle East African Journal of Ophthalmology, 19(1), 34–42. https://doi.org/10.4103/0974-9233.92114


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