infection, orbital abscess, and retrobulbar hematoma Flashcards
what separates the pre-septal and post-septal compartments
the tarsal plate and the fascia that connects to the periosteum
most common route of infection to the orbit
mc route to the orbit is the ethmoid sinuses
how do the orbital cavity and the cavernous sinus connect
orbital cavity and cavernous sinus connect
via
the superior and inferior ophthalmic VEINs
inferior veins are valveless as most veins in the face.
general workup for all orbital infections:
HPI - decreased visual acuity, decreased color,
labs - CBC, blood cultures
Exam: Proptosis, ophthalmalgia (orbital pain), IOP, snellen chart, EOM, PERRL, APD test (swinging light test), fundoscopic exam (papilledema - look up picture, optic nerve involvement),
consults: ophthalmology
Imaging: CT - 3mm cuts, look for EOM, distance of eyeball to rigid structure, rim enhancing lesion, fat stranding, edema of the extra ocular muscles (look up picture on radiopegia?
similarities and differences with retrobulbar hematoma to infection
trauma vs infectious source
retrobulbar hematoma - lateral canthotomy …
look up
preseptal cellulitis bacteria, antibiotics, when to do I and D
preseptal cellulitis
staph, strep, influenzea (think pneumonia organisms
can get chemosis
antibiotics - cover for MRSA (clinda, Bactrim)
I and D if abscess defined
Superior orbital fissure syndrome vs orbital apex syndrome vs cavernous sinus thrombosis
- Ophthalmoplegia: due to compression or damage to oculomotor, trochlear and abducens nerves
- Ptosis: due to loss of oculomotor motor supply to the levator palpebrae superioris and loss of sympathetic input (third order postganglionic) to Muller’s muscle
- Proptosis: due to decreased tension in the extraocular muscles with loss of innervation
- Fixed dilated pupil: due to loss of parasympathetic supply to the pupil by the oculomotor nerve
- Lacrimal hyposecretion and eyelid or FOREHEAD anaesthesia: due to damage to branches of the ophthalmic division of the trigeminal nerve
- Loss of corneal reflex: due to loss of afferent input from the ophthalmic division of the trigeminal nerve.
ORBITAL APEX SYNDROME:
all of the above PLUS Optic nerve involvement
CAVERNOUS SINUS THROMBOSIS
first sign is lateral gaze palsy then ophthalmoplegia, v1 AND V2 (vs just V1 in SOF/OA syndrome), and systemic issues including N/V, AMS, sepsis
https://eyewiki.aao.org/Superior_Orbital_Fissure_Syndrome
what is the MCC and other causes of post-septal orbital abscess and cellulitis
mcc of infection to posterior orbit is pan sinusitis (via ethmoid) - and the most common location is the medial aspect for abscess pushing the eye “Down and out”
other related to OMS: blepharoplasty, orbital trauma, odontogenic infection
non oms: ophthalmic surgery, retinal surgery, dacrocystitis (infection of the tear ducts)
mc bacteria of posterior orbital infections
fungi?
mcc of posterior orbital infections is staph and strep (same as pre-septal)
fungi: poorly controlled diabetics, Nucor and aspergillum can cause life threatening infections
tx of cellulitis vs abscess
indications for surgery - poor response to antibiotic tx (24 hours)
worsening visual acuity, APD, or other sx
large abscess greater than 10 mm
for boards - could do I and D if suspect abscess…
but cellulitis can do just antibiotics and watch
abscess DEF I and D.
approach for orbital abscess
transconjunctival with lateral canthotmy if needed and transcaruncular extension for medial approach
- lateral canthotomy if IOP high/lateral
OR endoscopic through the sinus
do you do steroids for orbital infections
you can - high dose steroids - what is high dose steroids - look up.
signs of cavernous sinus thrombosis
CAVERNOUS SINUS THROMBOSIS
first sign is lateral gaze palsy then ophthalmoplegia because cn 6 is right in the middle of the cavernous sinus.
Dilation of the retinal veins on the contralateral side may precede the lateral gaze palsy as mentioned above because of outflow issues (blue book pg 56)
pyrexia is seen with picket fence patter of high temperature spikes suggestive of thrombophlebitis.
v1 AND V2 (vs just V1 in SOF/OA syndrome), and systemic issues including N/V, AMS, sepsis
other include photophobia, proptosis (why?), ophthalmoplegia (3,4,6)< dilated pupils (why?),
lid edema and chemosis (secondary to not being able to drain the ophthalmic veins?)
what are some secondary sequela of cavernous sinus thrombosis
meningitis, encephalitis, blindness, brain abscess, pituitary infection, epidural and subdural empyemas, coma, death
how do infections travel to the cavernous sinus?
concerning area is the triangle from the corner of mouth, nose and medial cheek.
veins
1) facial vein, angular vein, ophthalmic vein, cavernous sinus
