Orbital inflammation – preseptal & retroseptal involvement. Thrombosis of cavernous sinus. Pseudotumor.
Orbital septum = thin fibrous layer arising from the periosteum along the inferior & superior orbital rims which fuses into the upper & lower eyelid retractors
- Important anatomic barrier in eyelids to prevent contiguous spread of infection from eyelids into orbital tissues
- Tissues anterior to the septum/ Preseptal = part of eyelids
- Tissues posterior to the septum/ Retroseptal = parts located in the orbit
Preseptal inflammations
- Skin traumas laying superficial to the orbital septum e.g. lacerations of eyelids, Horedolum [Gerstenkorn] or insect bites with under some instances concomitant superinfection of bacteria such as Staph.aureus or β-hemolytic strep.
- Spread of local infection such as dacryocystitis (inflammation of lacrimal gland)
- Remote infections of adjacent structures e.g. middle ear or upper respiratory tract, most frequently H.influenzae & Strep.Pyogenes
- Sings & symptoms:
- Unilateral, tender, erythematous periorbital or lid swelling
- NO proptosis, NO chemosis, visual acuity & ocular movements should be unimpaired! (Can therefore be differentiated from postseptal cellulitis)
Postseptal (orbital) cellulitis
= bacterial infection deep into the orbital septum
- Immediate treatment is essential since a delay in therapeutic management can lead to blindness due to optic nerve compression, septic cavernous sinus thrombosis or intracranial sepsis
- Often occurs in children
- Orbit is surrounded by paranasal sinuses, parts of their venous drainage happens through the orbit → Therefore extension of acute sinusitis via ethmoid bones occurs frequently e.g. by H.influenza, S.pneumoniae, in adults also sometimes anaerobic organisms
- Signs & symptoms:
- Characterized by fever, pain, eyelid swelling, erythema
- Proptosis, chemosis, limitations of extraocular movements, leucocytosis
- Non-axial proptosis suggests sub-periosteal/ intraorbital abscess
- Intracranial extension may cause meningitis & possibly brain abscess
- Differentiation of pre-/retroseptal inflammations: via symptoms, CT/MRI
Treatment
- Initial treatment is life-saving to prevent blindness, intracranial spread, etc.
- In all cases CT/MRI should be performed to prophylactically exclude abscess formation, intracranial involvement, etc.
- Preseptal inflammations:
- Usually treated as outpatients, with oral antibiotics e.g. amoxicillin/clavulinic acid
- In cases of dirty wounds or other suspicions of gram negative organisms add cephalosporins
- Patients should be monitored closely to prevent retroseptal spread
- Retroseptal inflammations:
- Hospital admission with parenteral antibiotics should be administered: 3rd / 4th generation cephalosporins, penicillins & metronidazole (in suspicion of anaerobes)
- Consultations with an otolaryngologist for surgical drainage of paranasal sinuses