EM Ophtha 2: Pearls, part 2

Question 1

remarks on using fluorescein

Answer 1

remove contact lens because these will be permanently stained

Question 2

positive Seidel test

Answer 2

Streaming of fluorescein-tinged aqueous humor
–seen in full-thickness laceration of the cornea

Question 3

normal size ratio of arteries to veins

Answer 3

2:3

Question 4

dilatation of pupils can by achieved by

Answer 4

one drop each of
1% tropicamide and
2.5% phenylephrine

Question 5

papilledema

Answer 5

disk margins are blurred
cup is diminished or absent
nerve head is elevated with vascular congestion

distinguishing feature is prolonged preservation of visual acuity (visually asymptomatic)

normal cup-to-disk ratio is less than 0.5; in glaucoma - increased

Question 6

normal intraocular pressure

Answer 6

10-20 mm Hg

Question 7

components of the anterior chamber

Answer 7

palpebral and bulbar conjunctiva
sclerae
cornea
anterior chamber
iris
*ciliary body

*ciliary body could not be examined with the slit lamp

Question 8

list orbital and periorbital infection in increasing severity

Answer 8

preseptal (periorbital) cellulitis
postseptal (orbital) cellulitis
subperiosteal abscess
orbital abscess
carvernous sinus thrombosis

Question 9

how to definitiively differentiate preseptal from postseptal cellulitis

Answer 9

contrast-enhanced ct scan of the orbits and sinuses

Question 10

remarks on preseptal cellulitis

Answer 10

primarily a disease of childhood, with most patients <10 years of age

symptoms: upper respi symptoms, low-grade fever, redness ann swelling of eyelids, epiphora

IMPORTANT:

1. eye itself is not involved
2. visual acuity and pupillary reaction are maintained
3. full painless ocular motility is preserved

Question 11

treatment of preseptal cellulitis

Answer 11

1. treated as outpatient
2. oral antibiotics: amoxicillin/clavulanic acid or a first generation cephalosporin
3. hot packs
4. close follow-up in 24-48 hours

Question 12

what is the term for excessive tearing

Answer 12

epiphora

Question 13

most frequent cause of postseptal cellulitis

Answer 13

spread of paranasal sinusitis, most commonly via perforation of the thin lamina papyracea of the ethmoid sinus

Question 14

other predisposing factors in postseptal cellulitis

Answer 14

spread of periorbital skin infection
seeding from bacteremia

trauma
intraorbital foreign body
ocular surgery

Question 15

signs and symptoms of orbital (postseptal) cellulitis

Answer 15

upper respi symptoms
fever

limitation in and pain with eye movement
abn pupillary response
dec VA

facial pressure
chemosis
proptosis

Question 16

This should lead you to suspect cavernous sinus thrombosis

Answer 16

headache
fever
deficits of CN III, IV, or VI

Question 17

Treatment of postseptal cellulitis

Answer 17

Vancomycin + ceftriaxone + metronidazole or clindamycin

or
pip/taz
or
ticarcillin-clavulanate
or
imipenem or meropenem

emergent lateral canthotomy if IOP is elevated or optic neuropathy is pressent