Emergency Medicine Q & A, 2009, Pg

Emergency Medicine Q & A, 2009, Pg


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chambers are deep and quiet. There is
no angle recession in either eye. His right lens is slightly displaced inferonasally. The remainder of his
examination is normal. Your ophthalmologist on call is not answering his pager. You should now:
a. Do nothing\u2014this patient requires only observation.
b. Begin a trial of miotic therapy in the right eye and arrange follow-up with an ophthalmologist in the morning.
c. Admit for emergent eye surgery in the morning.
d. Contact the partner of the ophthalmologist whom you cannot reach, as this patient needs immediate vitrectomy
of his right eye.
e. Place a protective eyeshield, keep the patient upright, and transfer to an eye specialty center.
The answer is b. The patient\u2019s complaint is monocular diplopia and is secondary to lens subluxation in the right
eye following blunt trauma. Miotic therapy may relieve his symptoms and prevent surgery in this case. If he cannot
tolerate miotics or if they fail to alleviate his diplopia, lens extraction and intraocular lens implantation would be
the next course of action. This evaluation can wait until morning.
102 Emergency Medicine Q & A: Pearls of Wisdom ...
9. A 40-year-old construction worker was inadvertently struck in his left eye 2 hours ago by a coworker
carrying a wooden beam. His visual acuity is 20/20 in the right eye, and counting \ufb01ngers at 3 ft in the left
eye. His globes are intact. He has an afferent pupillary defect in his left eye, and there is a rosette-shaped lens
opacity. Ophthalmoscopic examination shows an inferior vitreous hemorrhage of the left eye with a small
inferotemporal retinal tear. Your most pressing concern is the:
a. Vitreous hemorrhage.
b. Traumatic cataract.
c. Afferent pupillary defect.
d. Abnormal visual acuity.
e. Retinal tear.
The answer is c. An afferent pupillary defect in this setting should alert you to the possibility of traumatic optic
neuropathy. The patient should be started on a course of high-dose intravenous methylprednisolone and should be
observed closely for progressive visual loss. Surgical intervention may be indicated if visual decline continues while
on corticosteroid therapy. Other ocular injuries also should be addressed, but traumatic optic neuropathy should be
the most pressing concern.
10. A 14-year-old girl complains of sudden fever, unilateral eyelid redness, and double vision. You \ufb01nd
limitation of extraocular movement and pain when the patient tries to move her eyes. Your most important
diagnostic study is:
a. MRI.
b. CT scan.
c. Blood culture.
d. Eyelid culture.
e. White blood cell count.
The answer is b. This patient\u2019s presentation is suspicious for orbital cellulitis. A CT scan will assess and stage
orbital involvement, such as subperiosteal abscess or orbital abscess. It also can evaluate the paranasal sinuses. Blood
culture and eyelid culture results tend to be negative; therefore, antibiotic choice is empiric. White blood cell
counts cannot be used to differentiate between preseptal cellulitis and orbital cellulitis.
11. A 10-year-old patient complains of unilateral eyelid swelling and erythema. You suspect this is preseptal
(periorbital) cellulitis because on physical examination you \ufb01nd:
a. Limited ocular motility.
b. An afferent pupillary defect (Marcus Gunn pupil).
c. Tenderness and purulent re\ufb02ux from the lacrimal sac.
d. Resistance to retropulsion.
e. Eye pain and photophobia.
The answer is c. Pain and purulent re\ufb02ux from the lacrimal sac is likely from dacryocystitis, which is a common
predisposing condition for preseptal cellulitis. An afferent pupillary defect is caused by a lesion of the anterior visual
pathway (i.e., optic nerve and tract), and it is suggestive of orbital cellulitis. Resistance to retropulsion is a physical
\ufb01nding in the presence of an orbital mass. Eye pain and photophobia has a large differential diagnosis and does not
speci\ufb01cally point to preseptal cellulitis.
... CHAPTER 7 Head, Eye, Ear, Nose, and Throat Emergencies 103
12. A 33-year-old woman complains of red eyes with a watery discharge for 2 weeks despite treatment with
gentamicin and bacitracin eyedrops. She denies genitourinary symptoms but is sexually active. Your next
step is to:
a. Send conjunctival swab for routine bacterial culture and sensitivities.
b. Change to a combination antibiotic\u2013steroid eyedrop.
c. Do conjunctival scraping for Gram stain and Giemsa stain.
d. Change to a \ufb02uoroquinolone eyedrop.
e. Begin empiric systemic therapy with doxycycline.
The answer is c. Persistent conjunctivitis which does not improve with usual topical therapy may be caused by
chlamydia infection. Chlamydial sexually transmitted disease is characteristically asymptomatic in females.
Certainly culture and sensitivities will be useful if this is a resistant bacterial infection. However, the diagnosis of
chlamydia will be missed on routine culture without special collection and processing. Conjunctival scraping will
determine if bacteria predominate or if inclusion bodies diagnostic of chlamydia are present. Therefore, this is the
best answer. Changing the antibiotic or adding steroid without further study would not be ideal.
13. A 44-year-old man reports that he has been using neomycin eyedrops for 1 week to treat a red eye and
discharge. The discharge has stopped, but his eye is still red and irritated. On slit lamp examination, you \ufb01nd
injection of the small conjunctival vessels and a trace of punctate staining of the cornea. You should now:
a. Change to gentamicin eyedrops.
b. Change to an antibiotic\u2013steroid combination eyedrop.
c. Perform conjunctival scraping for Gram stain and Giemsa stain.
d. Discontinue the neomycin, and monitor the patient\u2019s progress.
e. Add systemic doxycycline.
The answer is d. Neomycin is known to cause irritation of the conjunctiva and the corneal epithelium. In this case,
it is most reasonable to stop the suspected agent and monitor the patient without subjecting him to further tests.
Empirically, changing the therapy is not ideal.
14. Corneal abrasions can lead to infection because:
a. Human tears contain a large number of pathogens.
b. Scarring occurs.
c. A de-epithelialized cornea is susceptible to infection.
d. The cornea is a \u201cprotected space,\u201d and white cells cannot migrate appropriately to aid in healing.
e. Meibomian glands frequently harbor occult pathogens.
The answer is c. A de-epithelialized cornea is more susceptible to infection. Such a cornea is vulnerable not only to
pathogens contaminating the foreign body that produced the abrasion but also to potential pathogens that are
present in the normal conjunctival \ufb02ora. Prophylactic topical antibiotics are generally prescribed for corneal
abrasions. The use of prophylactic periocular injections or systemic administration of antibiotics after corneal
abrasions is controversial.
104 Emergency Medicine Q & A: Pearls of Wisdom ...
15. A 47-year-old workman complains of severe left eye pain, which started 15 minutes ago while he was
hammering a nail into a wall. Your \ufb01rst step is to:
a. Perform an x-ray of the orbits.
b. Check visual acuity in each eye separately.
c. Place a drop of proparacaine in the eye for the pain.
d. Examine the eye with a slit lamp.
e. Order a CT scan of the orbits.
The answer is b. Before proceeding with any extensive ocular examination or treatment, vision should be checked
in each eye separately. Documenting the initial visual acuity of the patient, both for medical and medicolegal
purposes, is important.
16. In a patient with acute central retinal artery occlusion, sight can generally be retained if circulation is
restored within:
a. 30 minutes.
b. 60 minutes.
c. 90 minutes.
d. 120 minutes.
e. 150 minutes.
The answer is c. Because acute retinal artery occlusion is an ophthalmic emergency, efforts should be directed
toward restoring retinal circulation as soon as possible. It has been