Infective eye disease Flashcards
What is orbital cellulitis?
Severe sight- and life-threatening emergency due to infection of soft tissues posterior to the orbital septum
Where does orbital celluitis infection normally spread from?
- Extension of infection from periorbital structures - ethmoid sinusitis, face, globe, lacrimal sac or dental infection
- Direct inoculation of orbit from trauma
- Haematogenous spread from distant bacteraemia
What is classified as the orbital septum?
In the upper eyelid, the orbital septum blends with the tendon of the levator palpebrae superioris, and in the lower eyelid with the tarsal plate
What parts of the orbit does orbital cellulitis affect?
- Extraocular muscles
- Fatty tissues
What are the most commonly implicated organisms in orbital cellulitis?
- Streptococcus pneumoniae
- Staphylococcus aureus
- Streptococcus pyogenes
- Haemophilus influenzae
What are symptoms of orbital cellulitis?
Unilateral, rapid onset
- Erythema
- Swelling
- Severe pain
- Blurred vision
- Diplopia
- Headache
- Systemic features
What are systemic features seen in Orbital cellulitis?
- Fever
- Malaise
What are signs of orbital cellulitis?
- Lid erythema + chemosis
- Reduced periorbital sensation
- Pain
- Reduced visual acuity
- Proptosis
- Painful opthalmoplegia
- Optic neuropathy
Why do those with orbital cellulitis get opthalmoplegia?
Inflammation of extra-ocular muscles
How is orbital cellulitis staged?
Chandlers Classficiation - stage I-V
- Stage I - Preseptal
- Stage II - Orbital
- Stage III - sibperiosteal abscess
- Stage IV - Orbital abscess
- Stage V - Cavernous sinus thrombosis and infection
What is stage I of chandler’s classification of orbital cellulitis?
Preseptal cellulitis
What is stage II of chandler’s classification of orbital cellulitis?
Orbital cellulitis
What is stage III of chandler’s classification of orbital cellulitis?
Subperiosteal abscess
What is stage IV of chandler’s classification of orbital cellulitis?
Orbital Abscess
What is stage V of chandler’s classification of orbital cellulitis?
Cavernous sinus thrombosis and infection
How would you clinically assess someone with suspected peri-orbital/orbital cellulitis?
Distinguish between the two and assess for features of orbital cellulitis
- Painful eye movements?
- Reduced Visual acuity/Blurriness?
- Diplopia?
What investigations would you consider in someone with periorbital/orbital cellulitis?
- Bloods - septic screen
- Consider CT
What are indications for CT scan for someone with peri-orbital cellulitis?
- Central Signs
- Unable to assess vision
- Gross proptosis
- Bilateral oedema
- Opthalmoplpegia
- Deteriorating visual acuity
- No improvement at 24 hours
Why doesn’t everyone with peri-orbital/orbital cellulitis get a CT scan?
Significant radiation exposure in young population - therefore more risk than benefit unless clinical picture indicative of orbital cellulitis
What are the main complications of orbital cellulitis?
- Exposure keratopathy
- Raised intraocular pressure
- Central retinal artery/vein occlusion
- Endophthalmitis
- Optic neuropathy
- Orbital abscess
- Meningitis
- Brain abscess
- Cavernous sinus thrombosis.
What is CT used to visualise in orbital cellulitis?
Sinuses, orbit and brain - looking for abscesses and cavernous sinus thrombosis
What is peri-orbital cellulitis?
Infection of the soft tissue anterior to the orbital septum, which is commonly caused by sinusitis or facial skin lesions
What is the main feature of periorbital cellulitis?
Erythematous swelling around the eyelid
How would you manage peri-orbital cellulitis?
Empirical antibiotics - amoxicillin/ceftriaxone for 10 days
How would you manage orbital cellulitis?
Admit to hospital
- ENT and opthalmology referral
- CT orbit and sinuses
- IV Antibiotics - Ceftriaxone + Metranidazole +/- vancomycin
- Monitor optic nerve function - every 4 hours
How often would you monitor optic nerve function in someone with orbital cellulitis?
Every 4 hours
How would you manage an orbital abscess?
Surgical drainage
