Download The Eye - Calgary Emergency Medicine

The Eye
Ocular Pursuit
“Eye wanna win”
but
“There is no eye in team”
History
• Trauma
– Consider unrecognized trauma- awoke with
symptoms
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Pain? Itch? FB sensation?
Visual acuity changes, halos
Contact lenses- ? Overwear
Sick contacts/Viral symptoms
Prior surgery or eye disorders
Systemic disease
Eye
exam
(the basics.
From a non-ophthalmologist
who isn’t particularly
good
at examining eyes.)
if you can read this last line I’ll eat my shoe right here and now.
Eye exam
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Visual acuity
Visual fields
Pupil shape and reactivity
Lid closure
Foreign bodies
Ciliary flare
Foggy cornea (edema)
Corneal infiltrate
Fluorescein- corneal defects, Sidel’s sign
Anterior chamber cells
Intraocular pressure
Visual Acuity
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Snellen Chart
Use corrective lenses (or pinhole)
Examine each eye separately
If can’t read largest letter, go to finger
counting
• If can’t count fingers, check motion
perception
• If no motion perception, go to light
perception
Abbreviations which will impress
your chart reader
• OS – Left eye
• OD – Right eye
• OU – Both eyes
• VA – Visual acuity
Ocular Pursuit Question #2
• What does the latin abbreviation OS stand
for?
More Abbreviations
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L/L/L – Lids, lashes, lacrimal
C/S – Conjunctiva and Sclera
K – Cornea
AC – Anterior Chamber
I – Iris
L – Lense
AV – Anterior Vitreous
CF – Count Fingers
HM – Hand motion
LP – Light perception
Match the nerve with the
extraocular muscle!
• Extraocular Muscle
• Cranial Nerve
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• VI
Superior Oblique
Superior Rectus
Lateral Rectus
Medial Rectus
Inferior rectus
Inferior oblique
• III
• IV
Pupillary Reactions
• Patient looks in the distance
• Hold light in front of eye #1 for 3-5
seconds, then swing to the other eye
• Should get initial constriction, then dilation
Anterior – posterior
• Lids, lashes
• Conjunctiva, sclera, cornea
• Evert eyelids
• Anterior chamber
• Retina
Intraocular Pressure Measurement
• Tonopen – need to calibrate first
• Normal measurements 10 – 21 mmHg
Approach to Ophthalmic
Emergencies
• Diagnostic Category – trauma, vascular,
infectious, inflammatory, chemical
exposure
• Location - extraocular and periorbital,
conjunctiva, sclera, cornea, anterior
chamber, lens, posterior chamber, retina,
vascular
• Symptom
Symptom approach
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1. Vision loss
Painless
Painful
2. Eye pain
3. Red eye and discharge
4. Double vision
Painless Vision Loss
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Retinal Detachment
Central Retinal Artery Occlusion
Central Retinal Vein Occlusion
Vitreous hemorrhage
Occipital lobe TIA/CVA
Toxins (Methanol)
Central Retinal Artery Occlusion
• Anatomy
• Internal Carotid Artery –
– Ophthalmic Artery
» Central Retinal Artery
CRAO
History
• Sudden, painless, monocular blindness
• Most of the visual field - worse in the
central visual field
Causes
• Emboli – most common
• Vasculitidies (temporal arteritis)
• Trauma
EMERGENCY!!!
Yes. True. But…
• Loss of vision may be irreversible within
90 minutes. Needs emergent
ophthalmology referral.
• Unfortunately… not much evidence for any
therapeutic interventions. Studies tend to
be small, not one center, without
significant change in long term vision.
Therapies (you can try)
• Hemodilution – bolus 1-2 liters of normal
saline
• Ocular massage – closed lids – 10 -15
seconds – sudden release of pressure
• Rebreathing CO2 – paper bag strategy
• Intra-arterial thrombolysis
• Anterior Chamber paracentesis –
tetracaine – 30 guage needle – aspirate
0.1 ml.
Bottom line…
• Call the opthalmologist immediately if you
suspect this diagnosis.
• Post CRAO immediate window – treat like
TIA – need to look at risk factors (HTN,
dyslipidemia, diabetes, smoking), carotid
doppler U/S, look for Atrial fibrillation.
Central Retinal Vein Occlusion
• Again, sudden, painless, monocular vision
loss
• More common than CRAO (CRVO
prevalence ~ 1%, compared to ~ 1/10000
for CRAO)
• Ischemic and non-ischemic variants
Central Retinal Vein Occlusion
Branch Retinal Vein Occlusion
More treatments that may (or may
not) be helpful
• Aspirin
• Intravitreal t-PA
• Surgical options
• Treat underlying disease
Which of the following ocular
problems is most commonly
associated
with a patient report of “curtain-like”
vision loss?
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A. Vitreous hemorrhage
B. Retinal detachment
C. Optic neuritis
D. Central retinal artery occlusion
Retinal Detachment
Retinal Detachment
• Acute or subacute monocular vision loss
• Floaters
• Peripheral vision loss
• Patients might describe “curtain like” visual
loss
Retinal Detachment
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Occurs in 1/300 over the course of a lifetime
Risk factors:
Age
Previous cataract surgery
Focal retinal atrophy
Myopia
Trauma
Diabetic retinopathy,
Family history of retinal detachment
Uveitis
Prematurity
If you suspect it…
• Immediate ophthalmology consultation
• Surgical options
• Laser treatment of tears –
Vitreous Hemorrhage
• History – painless, monocular vision loss
• Patients may describe “haze”, “smoke”,
“streaks”
Vitreous Hemorrhage
• Causes:
• Diabetic retinopathy
• Posterior vitreous detachment
• Trauma (shaken baby)
Vitreous Hemorrhage
• Consult ophthalmology:
• Will look for any retinal tears which could
be mended
• Coag studies
• Avoid exertional activities which could
increase IOP
Doctor…
• My eye hurts!
• And I can’t see out of it!
Optic Neuritis
Physical exam
• Pain with eye movements
• Afferent pupillary defect
• May see optic disc swelling on fundoscopy
Optic Neuritis
• Inflammatory demyelination of the optic
nerve
• Most common in 20-40 year old women
• Association with multiple sclerosis
Imaging
• MRI:
• Optic nerve inflammation
• Periventricular white matter lesions
somewhat predictive of MS
Treatment
• Generally improves spontaneously over
days – weeks
• ?Steroids – may decrease progression to
MS – talk to Neurology
Which of the following is one of the
diagnostic criteria for temporal
arteritis?
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A. Bounding temporal artery pulse
B. Erythrocyte sedimentation rate of > 20
C. New headache
D. Age > 70
Temporal Arteritis
• Medium/large vessel vasculitis
• Carotid artery branches
• Disease of the elderly
Physical Exam
• Palpate – firm, tender temporal artery
• Joint pain with movement
• Visual acuity
Diagnosis
• Age > 50
• New Headache
• Abnormalities of the temporal artery (tender,
pulseless)
• ESR > 50
• Positive biopsy
• 3/5 positive findings give sensitivity of 93% and
specificity of 91%
Treatment
• Consult Ophtho and/or Rheumatology
• High dose steroids
Amaurosis Fugax
• Transient monocular vision loss (minutes)
• TIA of the eye
• Neurology consult
Name the phenomenon
demonstrated in this picture
Cortical Blindness
• Think about it in the patient with vision loss
and the absence of eye pathology
• Occipital lobe insults, vertebrobasilar
infarcts
• Usual stroke treatment
Question – name 3 causes of this
condition
Lateral Canthotomy/Cantholysis
• Procedure to decompress a compartment
syndrome of the orbit
Retro-orbital hematoma
Primary Indications
• Decreased visual acuity
• Intraocular pressure > 40 mmHg
• Proptosis
Contraindication
• Globe rupture
The things you’ll need to do your
very own lateral
canthotomy/cantholysis
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1. Lidocaine with epinephrine
2. Syringe with 25-gauge needle
3. Hemostat or needle driver
4. Iris or suture scissors
5. Forceps
Step 1
• Prep skin
• Anaesthetize – lido with epi into lateral
canthus
Step 2
• Apply needle driver or hemostat from
lateral canthus to bony orbit to
devascularize the area for 30 – 90
seconds.
Step 3
• Remove the hemostat and cut the
demarcated area 1 – 2 cm laterally
Step 4
• Use the forceps to pull down the lower
eyelid until you can see the inferior lateral
canthal tendon
• Cut through it
Step 5
• Reassess IOP
• If still greater than 40 mmHg haven’t
provided adequate pressure relief:
• Expose the superior lateral canthus and
cut this too.
Congratulations!
What is the mechanism of
action for fomepizole (4-MP) in
the treatment
of acute methanol toxicity?
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A. Active diuresis of methanol through the kidney
B. Enhanced hepatic conversion of the toxic methanol molecule
through CYP 450 3A
C. Competitive elimination with bile
D. Competitive inhibition of alcohol dehydrogenase
E. Inhibits blood flow through affected organs by the angiotensin
pathway
Examination of a ruptured globe
with fluorescein may demonstrate
displacement of the fluorescein due
to aqueous humor flow.
This has been named the:
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A. Seidel test.
B. Adie’s pupil.
C. Gunn’s phenomenon.
D. Hoover’s test.
Intraocular pressures
associated with acute angle
glaucoma tend to be:
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A. > 7 mmHg.
B. > 14 mmHg.
C. > 21 mmHg.
D. > 28 mmHg.
Chemical burns to the eye are true
ophthalmologic emergencies.
Generally
speaking, which class of chemicals
typically causes more damage?
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A. Acids
B. Bases
C. No difference
D. pH 7.4
What is the hallmark finding of
vertebrobasilar syndrome?
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A. Crossed neurologic deficits
B. Unsteady gait
C. Afferent pupilary defect
D. Bitemporal hemianopsia
E. “Cherry red” macula
Name that Finding/Disease!
Epidemic keratoconjunctivitis
Nodular episcleritis
Scleritis
Acute Angle-Closure Glaucoma
Acute angle closure glaucoma
• Acute angle closure glaucoma has at least 2 of the
following
• symptoms:
• • ocular pain
• • nausea/vomiting
• • history of intermittent blurring of vision with halos
• And at least 3 of the following signs:
• • IOP > 21 mmHg
• • conjunctival injection
• • corneal epithelial edema
• • mid-dilated nonreactive pupil
• • shallow chamber in the presence of occlusion
References
• Basic Ophthalmology – 7th edition. Cynthia Bradford. American
Academy of Opthalmology.
• Med Clin N Am 90 (2006) 305–328
• Emerg Med Clin N Am
26 (2008) 233–238
• Ophthal Plast Reconstr Surg. 1994 Jun;10(2):137-41. Efficacy of
lateral canthotomy and cantholysis in orbital hemorrhage
• CJEM 2002;4(1):49-52
• Cochrane Database Syst Rev. 2009 Jan 21;(1):CD001989.
Interventions for acute non-arteritic central retinal artery occlusion.
• Emergency Medicine Reports. Volume 29, Number 17. August 4,
2008.