Orbital Cellulitis

Orbital tissue is involved in addition to the Eyelid infection in Preseptal Cellulitis findings
1. Infection may involve the Muscle, fat and connective tissue contained in the orbital compartment
Bacterial Ethmoid Sinusitis extension to involve orbit (60-80% of cases)
1. Extends via thin medial bony wall into orbit
2. Extends via retrobulbar veins (no valves) into lids
Typical Organisms
1. Streptococcus Pneumoniae
2. Group A Streptococcus
3. Staphylococcus aureus
4. Moraxella catarrhalis
5. Haemophilus Influenzae (under age 3 years, decreasing due to Immunization)
6. Mixed Bacterial Infection including Anaerobes
Organisms in Immunocompromised patients (e.g. HIV Infection or AIDS)
1. Pseudomonas aeruginosa
2. Opportunistic fungal infections

Starts as mild inflammatory edema
1. URI history
2. Low grade or absent fever
3. Slowly progressive clinical course
4. Swollen and discolored Eyelid
Progresses to orbital involvement
1. Fever
2. Proptosis (Exophthalmos)
3. Pain and limitation of eye Extraocular Movement
  1. Key distinguishing feature from Preseptal Cellulitis
4. Diplopia on side gaze due to inability to move eye
5. Marcus Gun Pupil (relative afferent pupilary defect)
  1. Swinging Flashlight Test abnormal (affected pupil constricts less in response to light)
6. Chemosis
7. Retinal Exam
  1. Venous dilatation and tortuosity
8. Papilledema
9. Decreased Visual Acuity

Modalities
1. CT Sinuses and orbits with IV Contrast (preferred in most cases) or
2. MRI sinuses and orbits
Indications: Distinguish preseptal from Orbital Cellulitis (and evaluate sinus involvement)
1. Change in Visual Acuity
2. Proptosis
3. Decreased Extraocular Movements
4. Diplopia
5. Eye not able to be examined (e.g. due to local Eyelid Edema)

General
1. Observe in hospital with at least daily Visual Acuity and Pupillary Light Reflex
2. Repeat CT Sinuses/orbits if not improved in 48 hours
Antibiotics course: 7-14 days
Parenteral antibiotics (initial 2-3 drug regimen)
1. Antibiotic 1 (choose 1)
  1. Vancomycin 15-20 mg/kg IV every 8-12 hours (preferred) OR
  2. Daptomycin 6 mg/kg IV every 24 hours OR
  3. Linezolid 600 mg IV every 12 hours
2. Antibiotic 2 (choose 1 )
  1. Piperacillin-Tazobactam (Zosyn) 4.5 g IV every 8 hours OR
  2. Ceftriaxone 2 g IV every 24 hours AND Metronidazole 1 g IV every 12 hours OR
  3. Moxifloxicin 400 mg IV every 24 hours (if Penicillin allergic)
Oral antibiotics (once infection controlled and based on microbiology)
1. See Preseptal Cellulitis management
2. Consider additional MRSA coverage (e.g. Septra, doxycyline)
3. Amoxicillin-Clavulanate (Augmentin)
4. Cefuroxime (Ceftin) or
5. Cefpodoxime
6. Cefprozil (Cefzil)
Surgical drainage indications
1. Large abscess
2. Significant symptoms
3. Insufficient improvement on antibiotics
References
1. (2017) Sanford Guide, accessed on IOS 2/2/2017
2. Carlisle (2015) Am Fam Physician 92(2): 106-12 [PubMed]

Advanced AIDS
1. Associated with poor outcomes related to Pseudomonas and opportunistic fungal infections
2. Johnson (1999) Arch Ophthalmol 117(1): 57-64 [PubMed]