Ocular Infection

Question 1

Compare/contrast Preorbital + orbital cellulitis:

Answer 1

Orbital septum: just behind lids

Question 2

Orbital cellulitis:

Answer 2

Orbital septum: just behind lids

ABOUT
Secondary spread from:
- Sinusitis
- Dental
- Periorb structures (lid, nasolacrimal duct etc.)

*FEATURES:
- Proptosis
- Chemosis
- +- pupil defects
- Raised IOP, firm
- Painful eye movements
- Optic neuropathy, reduced VA, swollen optic disc

COMPLICATIONS:
- Sepsis
- Abscess
- Visual loss
- Cavernous sinus thrombosis
- Secondary meningoencephalitis

Do a CT sinus/orbits/ venogram for source, + exclude cavernous sinus thrombosis (+ other DDx)

Question 3

DDx for orbital cellulitis:

Answer 3

Sever pain, fever, eye swelling

Cavernous sinus thrombosis
Osteomyelitis
Retroorbital abscess
Endophthalmitis
Scleritis
Retrobulbar haematoma

Question 4

Cavernous Sinus Thrombosis: anatomy

Answer 4

RECIEVES DRAINAGE FROM:
- Orbits
- Face (“danger triangle”)
- Middle, deep + inferior cerebral veins

CONTAINS:
- Internal carotids
- Pituitary
- Sympathetic fibres (Horners)
- Optic chiasm
- CN III, IV, V1/V2, VI (oculomotor, trochlear, abducens, trigeminal oph/max)

COMMUNICATES WITH:
- Brain!

Optic nerve not within, but closely above

Question 5

Cavernous Sinus Thrombosis: features

Answer 5

Septic thrombosis originating from sinusitis, orbits, “danger triangle”, dental.

Extremely rare
Very bad
–> 20% die. 60% have serious morbidity.

Think about associated structures:
- Meningoencephalitis, seizure.
- Horner’s
- CN III palsy: down + out, anisocoria, mydriasis
- CN IV palsy: up + in
- V1, V2 numbness
- CN VI palsy: in
- Pituitary insufficiency
- Papilloedema, vision loss

….+ looks exactly like orbital cellulitis, but with PALSIES (not just mechanical restriction)

Question 6

Cavernous Sinus Thrombosis: treatment

Answer 6

IV Ceftriaxone + Fluclox
+/- Vanc

Question 7

Cavernous Sinus Thrombosis: treatment

Answer 7

IV antis as per source (dental, sinus etc.)

Steroids, anticoagulation not established
Not surgery.

Question 8

Answer 8

Dacrocystitis

Infected nasolacrimal gland
Skin flora

Warm compresses
Antibiotics as per skin