Painful Proptosis in a Diabetic With a Rapidly Deteriorating Eye
A 62-year-old poorly controlled diabetic man presents with 4 days of right orbital pain, swelling, and decreasing vision. He has a fever of 38.4°C and has just completed a course of oral antibiotics for a 'sinus infection'. Vision is 6/60 right and 6/6 left. There is right proptosis of 4 mm, chemosis, restricted extraocular movements in all directions, and a dilated pupil with a reduced corneal sensation. Fundoscopy shows a swollen disc. CT shows opacification of the right ethmoid and maxillary sinuses with orbital fat stranding and a small subperiosteal collection medially. He is systemically unwell with a raised white cell count.
1. What is the diagnosis, and what are your immediate management steps?
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Diagnosis: Right orbital cellulitis with a subperiosteal abscess, likely secondary to ethmoid sinusitis, in a diabetic patient. The combination of proptosis, ophthalmoplegia, reduced corneal sensation, a dilated pupil, and disc swelling raises concern for cavernous sinus involvement or orbital apex involvement, and mucormycosis must be considered in a poorly controlled diabetic.
Immediate steps:
- Admit, IV access, cultures - blood cultures, sinus aspirate if possible, and urgent ENT review.
- Broad-spectrum IV antibiotics - cover staphylococci, streptococci, and anaerobes; add antifungal cover (e.g. liposomal amphotericin B) if mucormycosis is suspected (diabetic, black eschar, orbital apex signs, rapid progression).
- Urgent CT/MRI with contrast of orbits, sinuses, and brain - assess abscess size, cavernous sinus, and intracranial extension.
- Surgical drainage - the subperiosteal abscess with visual compromise and ophthalmoplegia is an indication for urgent endoscopic sinus surgery and abscess drainage.
- Control diabetes - insulin sliding scale, involve endocrinology.
- Monitor vision, pupils, and motility hourly; involve ophthalmology, ENT, and infectious diseases.
- Steroids - only after infection control is established and in discussion with the team; not acutely.
2. How do you distinguish bacterial orbital cellulitis from mucormycosis, and why does it matter?
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Bacterial orbital cellulitis:
- Usually follows sinusitis; fever, proptosis, chemosis, pain, ophthalmoplegia.
- Responds to antibiotics and drainage; common organisms are Streptococcus, Staphylococcus, and anaerobes.
Mucormycosis (e.g. Rhizopus):
- Poorly controlled diabetes or immunocompromise is the classic setting.
- Black eschar on the palate or nasal turbinates, facial numbness, reduced corneal sensation, dilated fixed pupil, and rapid progression over hours to days.
- May show cavernous sinus thrombosis and intracranial extension.
- Does not respond to antibacterials; requires urgent surgical debridement and high-dose liposomal amphotericin B.
Why it matters: bacterial cellulitis is managed with antibiotics ± drainage, while mucormycosis is a surgical and antifungal emergency with high mortality; delay costs life and vision. The presence of diabetes, reduced corneal sensation, a dilated pupil, and rapid deterioration should trigger antifungal cover and urgent ENT/surgical debridement before culture results return.
3. What are the sight- and life-threatening complications you must counsel about, and how do you monitor for them?
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Sight-threatening:
- Compressive optic neuropathy from the abscess or orbital apex involvement - monitor acuity, colour vision, RAPD, and disc appearance; any deterioration mandates urgent decompression.
- Central retinal artery occlusion from orbital compartment syndrome - check for a relative afferent pupillary defect and fundoscopy.
- Corneal exposure from proptosis and lagophthalmos - lubricants, taping, tarsorrhaphy if needed.
- Endophthalmitis if the infection spreads intraocularly - rare but devastating.
Life-threatening:
- Cavernous sinus thrombosis - bilateral signs, cranial nerve palsies, headache, and systemic sepsis; MRI/MRV.
- Intracranial extension - meningitis, subdural empyema, brain abscess; monitor neurology and repeat imaging if worse.
- Sepsis - vital signs, lactate, and organ function.
Monitoring: hourly neuro-observations and visual checks initially, daily review by ophthalmology and ENT, repeat imaging if no improvement at 48–72 hours or if deteriorating, and a low threshold for repeat surgical drainage.