Download RECOGNIZING OPHTHALMOLOGIC EMERGENCIES

RECOGNIZING OPHTHALMOLOGIC EMERGENCIES
Benjamin R. Doolittle, M.D., M. Div.
WEEK 22
Learning Objectives:
1. To recognize the difference between those ophthalmologic diseases which may be
managed by a primary care physician and those that necessitate emergent referral
2. To identify the differential diagnosis of acute visual loss and acute visual change
3. To understand the fundamentals of treatment and pathophysiology for ocular emergencies
CASE ONE: Pain, Purulence, and Photophobia
You arrive in your clinic in the morning to discover a 25-year-old woman who shares, “I
have had a cold the past two days and woke up this morning with my right eye all red and
gross. I can’t stop itching it. What is going on, and what are you going to do to help me?"
Your history further reveals mild photophobia, discomfort, but no feeling of a “grain of
sand” on her eye. Your exam shows 20/20 vision, normal extra-ocular movements, and
normal papillary reflex. Her right conjunctiva is hyperemic and inflamed. Indeed, you
note a yellow discharge that has matted her eyelid.
Questions:
1. What is going on, and what are you going to do?
This is bacterial conjunctivitis. It is not an emergency. It is caused by both gram
positive and negative bacteria, and easily treated with topical antibiotics. Topical
gentamicin or tobramycin eyedrops four times a day for 7-10 days has been
recommended. Polytrim – a sulfa – is also widely used and inexpensive. Topical
fluoroqinolones are used for more severe infections.
Keep this case in mind as we continue with our busy day in the office.
CASE TWO: Sudden, Unilateral, Painless Loss of Vision
Later in the morning, a long-time patient of yours comes into the office. He is 55 with
severe diabetes. Although diligent with his illness, he has had long stretches of time with no
follow-up or lab work due to inconsistent health insurance.
He shares, “I was driving to work when suddenly I couldn’t see out of my right eye. It just
went blank. I saw the stop sign, and then suddenly it wasn’t there anymore. I came right
over to have you check it out.
You note that his last Hgb A1C, six months ago, was 9.9. He has never seen an
ophthalmologist.
2. What are the six features of the eye exam (hint: it’s in the article!), and what are
some aspects to which you should pay particular attention?
The six parts of the eye exam are the following: visual acuity, visual field, pupils, extraocular muscles, anterior segment, and posterior segment.
In this particular case, the patient’s visual acuity should be carefully assessed. As noted
in the article, if the vision is less than 20/40, having the patient read the eye chart
through a pinhole will give an approximation of the best corrected vision. If the patient
still cannot see through the pinhole, the next step is to assess if the patient can count the
examiner’s fingers. If unable to do so, the next step is to discern if the patient can detect
hand movement, and if unable to do so, determine if the patient can detect light.
In a patient with severe diabetes, this story is most concerning for vitreous hemorrhage
with retinal detachment; amaurosis fugaxis is also a consideration.
CASE TWO CONTINUED:
On exam, you discover that the patient cannot see the eye chart with the right eye, cannot
count the fingers on your hand, and cannot detect hand motion. When you shine a penlight
in the right eye, the patient reports he can detect the light. The visual field exam is
compromised by his inability to see, but he reports he can see the light in all visual fields.
The papillary exam and extra-ocular exam are essentially normal. You note no lesions on
the conjunctiva or the cornea.
You hesitate with the ophthalmoscope – you never had great technique as a medical
student. Nonetheless, you are able to make out the retina on the left eye. On the right eye
however, you note that the red reflex is obscured, and discerning the retinal vessels is
difficult.
3. What is your diagnosis, and what are you going to do?
As above, the most likely diagnosis of SUDDEN, UNILATERAL, and PAINLESS loss of
vision in a person with diabetes is vitreous hemorrhage due to disorganized retinal
vessels (e.g., fragile microaneurysms, neovascularization, exudates). Retinal detachment
is also a possibility but usually presents with a different story (“rays of light” usually on
the peripheral visual fields, and may be acute or subacute). Amaurosis fugax – occlusion
of the retinal artery – results in sudden, unilateral loss of vision but would NOT result in
the clinician being unable to visualize the retina.
The management for all of the above is immediate evaluation by an ophthalmologist.
Vitreous hemorrhage is often managed expectantly, but may require laser coagulation. If
time permits, it might be helpful to review the proper technique of the ophthalmoscope.
CASE THREE: Sudden, Unilateral, Painful, Loss of Vision
Late in the evening – you are wrapping up your schedule - an elderly woman presents to
your office in moderate distress, clutching the left side of her face. She was in the backyard
at dusk when her left eye suddenly began to hurt. “All at once, my eye became so
incredibly painful. In fact, I have a headache that is so bad that I threw up twice.”
On exam, you note that the visual acuity of her left eye is 20/200. Her visual fields appear
intact but are compromised by her poor vision. Her left pupil is slightly dilated, unreactive
to light, and has an irregular border. Her extraocular muscles are intact. The anterior
segment reveals a hazy, edematous cornea. The patient is not compliant with a posterior
segment exam due to discomfort.
4. What is your leading diagnosis?
This story is most consistent with acute angle-closure glaucoma. The NEJM article does
a nice job of explaining the different etiologies of PAINFUL and PAINLESS visual loss.
The ophthalmic branch of the Vth nerve innervates the eye’s surface - the cornea,
conjunctiva, and the iris. Thus, PAINFUL loss of vision usually point towards problems
of the anterior chamber, whereas PAINLESS loss of vision suggest posterior segment
disease (i.e. vitreous or retina).
Other etiologies of acute and painful change in vision include corneal abrasion, keratitis,
iridocyclitis, and conjunctivitis from an allergic, viral, or bacterial source. Perhaps the
most ominous is an infection with herpes simplex, which often presents with symptoms
similar to a corneal abrasion. This can be a tricky diagnosis to make, but the dendritic
ulceration is most easily visualized with fluorescein (see case 4 below and Figure 10 in
the article).
Also, important to mention, is that the eye is the “window to the body.” Thus, when
discussing visual compromise, we must consider such systemic disease as tuberculosis,
collagen vascular disease (Reiter’s syndrome, temporal arteritis, sarcoid, etc.) and
syphilis.
5. Describe the physiology and treatment of acute angle-closure glaucoma.
Acute glaucoma usually occurs in ambient light and when the pupil needs to dilate, more
commonly occurring among patients who are far-sighted due to the relatively shorter
axial length of their globe. In a healthy eye, the vitreous flows from the posterior segment
into the anterior segment, then out through the delicate, trabeculated canals into the
venous system. When the pupil dilates, the iris bunches up or “accordions” against the
outflow tract of the vitreous (the Canal of Schlemm). Acute angle-closure glaucoma
occludes this outflow system, which results in a rapid rise in intra-ocular pressure. In
fact, gentle palpation through closed lids may reveal that the affected eye is more firm
than the normal one. The treatment consists of emergent laser iridectomy to relieve the
blockage.
6. What is the Take-Home Point?
Any severe eye pain or a visual defect merits strong consideration for immediate
ophthalmologic evaluation, especially if corneal abrasion or conjunctivitis are ruled out
by history and physical. It is not enough to have our patients “call their eye doctor
tomorrow,” but rather, it is beholden upon us to arrange transfer for such patients. In
the same way that we would transfer a patient with active chest pain to the ER for
evaluation of unstable angina, so we are called to transfer patients with severe eye pain
to an ophthalmologist.
CASE FOUR: Sudden, Unilateral, Painful, Decrease in Vision
Your last patient of the day is a 30-year-old gentleman who presents with a red, painful
right eye, decreased visual acuity, and photophobia that has become progressively worse
over the past two days. He does not wear contact lenses, cannot recall any trauma, but
notes, “There does feel like there’s something on my eye ball.”
On exam, his visual acuity in his right eye is 20/70. His right conjunctiva are markedly
inflamed, but without purulent discharge. You do not notice any abnormalities of the
cornea. He is unable to hold still for the retina exam.
You are concerned about the degree of his pain, in a situation that is very different from
bacterial conjunctivitis. You apply topical tetracaine, which relieves his discomfort, and
fluorescein dye. You notice an irregularly shaped ulcer, which is “dendritic” or
“spiculated”. (If one was to steer away from medical jargon, one might say that it looks
like the shoreline of the Chesapeake Bay or perhaps Rhode Island, see for yourself in
Figure 10 of the NEJM article!).
“Hmm,” you say to yourself. “What do I do now?”
7. What do you do now? What do you think is the leading diagnosis?
This is most consistent with herpes simplex keratitis. See question 4 above for the
differential.
Herpes infection is a sight-threatening infection, which often can mimic other, less
insidious etiologies, such as idiopathic or allergic inflammation, as well as TB and
connective tissue disease. The treatment for herpes simplex is trifluridine (Viroptic) nine
times a day x 21 days or vidarabine ointment. Unfortunately, there is a 30-50%
recurrence in two years, but this rate decreases with the administration of acyclovir
400mg bid.
The challenge is that IF the lesion looks benign, a less-informed physician may be
tempted to treat with a topical steroid, resulting in unchecked progression of the herpes
infection. The stakes are high, and one must have a high index of suspicion and low
threshold to refer. One quality that increases our concern is the presence of a
“hypopyon” – a layer of white cells in the anterior chamber suggestive of pus or any
corneal infiltrate (see Figure 9).
If one suspects herpes simplex, immediate referral is warranted.
References:
1. Shingleton, BJ & O’Donoghue, MW. Blurred vision, NEJM; 2000; 343 (8): 556-562.
Additional References:
1. Leibowitz, HM. The Red Eye, NEJM; 2000; 343(5): 345-351.
2. Wilhelmus, KR, Beck, RW, Moke, PS, Acyclovir for the prevention of recurrent herpes
simplex virus eye disease, NEJM 1998; 339:300-06.