I have always felt that the eye has not been given the
amount of time and detailed education that it deserves during med school
training; and as a result, while doing my internship emergency rotation, every
time a patient presents with an eye issue, I would secretly pray: “Please not
me, not me…” So below are some general dos and don’ts when approaching the eye:
·
History and examination should include these
aspects (PLOAFF):
o
Pupillary reactions
o
Lids and ocular adnexa
o
Ocular movement
o
Acuity
o
Fundus
o
Fields to confrontation
·
Never put pressure on the eye!
·
Never use atropine drops to dilate the pupil!
Use short-acting mydriatic ONLY if necessary—and never when the ocular
state/optic nerve function needs to be monitored.
·
X-ray the orbits when suspecting intraocular
foreign body—request X-rays with eyes in up and down gazes.
·
Never use steroid drops in the emergency
setting.
·
Do not apply ointment in cases suspected of
having a penetrating injury.
·
Do not persist in removing a foreign body is
it’s not easily removed.
·
Always provide systemic analgesia in cases of
corneal injury.
·
Always pad an eye after instilling local
anesthetic.
·
Always refer children with squints!
Regarding the use of a slit lamp, I’m kind of ashamed to say
that I’ve only ever used it to check for corneal ulceration. I don’t really
know all the other uses of the slit lamp and how to perform these tests; so
I’ve looked up some useful videos which go through all the basics of the slit
lamp use. (The third one is a gem.)
Moving on to some of the emergency presentations involving
the eyes. These can be divided into approximately five big categories: foreign
body, burns, trauma, painful red eye, and sudden loss of acuity.
Obviously, if there are foreign bodies within the eye, the
goal is to locate and remove that object. Foreign bodies can be present in the
lid, conjunctiva, cornea, and intraocular (remember to get that orbital
X-ray!); they often cause abrasions too so check thoroughly with fluorescein.
The main management is to rinse with lots and lots of saline, removal of
foreign object, antibiotic drops qid, and tetanus prophylaxis.
The management of chemical burns is very similar to managing
skin burns—first rinse and rinse with lots of saline! Local anesthetic and
systemic analgesia can be used. Examine thoroughly to make sure all source of
the chemical is removed. In thermal burns the principles are similar; start
antibiotic drops and pad if possible. Flash burns can result from UV light, and
the pain can start up to 6~12 hours after the injury and last for 24 hours;
systemic analgesia, sedation, antibiotic ointment, and padding are usually
needed.
Blunt force trauma can happen anywhere on the eye, and the
history is not a good guide to the severity of the injuries—so beware! The key
is to determine where the bleeding is! Although the subconjunctival hemorrhage
looks really bad, it’s actually not that bad; only reassurance is needed. The
hyphaema doesn’t look that bad in contrast, but it can cause secondary
glaucoma; and there can be a more severe secondary hemorrhage 2~3 days later.
This requires urgent ophthalmology consultation within 24 hours. Remember to
avoid aspirin. Vitreous hemorrhage and choroidal hemorrhage also need
consultation within 24 hours to exclude retinal detachment. The most urgent of
all eye hemorrhages is the orbital hemorrhage, which usually is accompanied by
blowout orbital fracture (RESTRICTION OF MOVEMENT AND DOUBLE VISION)—this is
sight threatening and may need urgent decompression—especially if there is
reduced vision, nonreactive pupils, or proptosis.
The painful red eye is a very scary topic. There are two
ways of approaching it. The first way is to divide it into two big categories:
inflammation or glaucoma. Inflammation would include acute conjunctivitis,
acute keratitis (HERPES SIMPLEX ULCERATION), acute iritis (CILIARY INJECTION),
and orbital cellulitis. Essentially the management is to swab the eye and start
antibiotics/antiviral therapy; dilate the eye and give steroid drops for acute
iritis. Acute narrow-angle glaucoma is sight threatening, so must be considered
in all unilateral painful red eye. Tell-tale symptoms and signs are HALO AROUND
LIGHTS, FIXED MID-DILATED PUPILS, nausea and vomiting, SHALLOW ANTERIOR
CHAMBER, and increased intraocular pressure (>40mmHg). Treat with topical
beta-blockers, adrenergics, and cholinergics and systemic carbonic anhydrase
inhibitors and hyperosmotic agents. Refer urgently.
The second way to approach the red eye is by categorization
of accompanying symptoms:
·
Light sensitivity—iritis, keratitis, abrasion,
ulcer
·
Unilateral—as above + herpes simplex, acute
angle closure glaucoma
·
Significant pain—as above + scleritis
·
White spot on cornea—corneal ulcer
·
Blurred vision—all of the above
·
Non-reactive pupil—acute glaucoma, iritis
·
Copious discharge—gonococcal conjunctivitis
Sudden loss of vision in a “white eye” usually means an
occlusion of a blood vessel or retinal detachment. Retinal artery occlusion is usually
painless, causing partial/total loss of vision, pale disc, retinal edema,
CHERRY RED SPOT, and narrowed arteries; remember to investigate for the CAUSE
such as temporal arteritis or emboli. Management includes lowering intraocular
pressure (IV acetazolamide 500mg), dilate blood vessels by giving carbagen
(95%O2 5%CO2) or rebreathing into paper bag, ESR levels, and urgent referral.
Retinal vein occlusion can present also present as painless loss of vision, but
there is usually dilated retinal veins with multiple hemorrhages through out
retina and swollen disc. HISTORY OF FLASHES AND FLOATERS and partial field loss
indicate retinal detachment; the retina is grey, elevated in a “veil-like”
manner. Urgent referral needed. Another case to refer urgently is optic
neuritis; the loss of vision is variable, but key symptom is CENTRAL FIELD
LOSS, afferent pupillary defect, and marked loss of red saturation.
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