Heuristic Errors in Medicine:
The Patient with a Red Eye
Richard K. Reed, M.D.,
F.A.C.P.
History
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CC: Problem with right eye
PI: RJ is a 40 yo female with Downs
Syndrome with itching of the right eye for 3
days. She had associated pain in the eye.
Her caregiver could not restrain her from
rubbing the eye. There was no known
history of trauma to the eye. She had no
recent URI symptoms.
PMH
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Downs Syndrome – functions as 3 yo
Leukemia as a child
Stroke as result of complication of chemotherapy
for leukemia
Obesity
Hypertension
Hyperlipidemia
Primary hypothyroidism
Sleep apnea
Social History
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Medications:
- HCTZ 25 mg. daily
- Lisinopril 10 mg. daily
- Levothyroxime 100 mcg. daily
- Lovastatin 40 mg. daily
- Citalopram 20 mg. daily
- D3 2000 units daily
- B12 1000 mcg daily
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NKA
No alcohol, tobacco, or other drug abuse
Needs help with most ADLs
Family History
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Father – died recently of complications of
diabetes, renovascular hypertension, chronic
renal disease, ischemic heart disease
Mother – died in 1980s of metastatic breast
cancer
Aunt – died recently of complications of
diabetes and heart failure
ROS
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No recent URI symptoms
No headache
No fever
No known head or eye trauma
No known abuse issues
Physical Examination
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BP 130/80
Pulse 64
RR 16
Temp 97.4
Weight 170#
Height 4’7”
BMI 39.5 kg/m2
No known narcotic or elicit drug use
No tobacco use
Physical Examination cont.
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Gen – obese, Downs phenotype, constantly
rubbing her right eye
HEENT
-visual acuity – not able to access
-examiner difficulty on observing right eye
-right eye red with conjunctival suffusion
-brief look at cornea- no problem
-fundus exam impossible
-fluorescein staining – NA
-slit lamp exam - NA
Physical Examination cont.
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Neck – short
Chest – clear
Heart – RRR with no murmur
Abdomen – obese, no organomegaly
Extremities – mild pretibial edema
Neuro – wheelchair bound; residual neurologic
sequelae of mild left hemiparesis
Assessment
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Right red eye – conjunctivitis, iritis or corneal
abrasion
Downs Syndrome
Obesity
Plan
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Unsure of correct diagnosis, I referred her to
an ophthalmologist.
Clinical Course
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Ophthalmologist
1. He did eye exam the following morning and
prescribed eye drops.
2. She returned to see him in 4 days.
a. Ophthalmologist was apparently unable to adequate exam.
b. With suspicion for underlying pathology, he took her to
surgery for exam under anesthesia and found a corneal
perforation.
c. Evisceration (not enucleation) procedure was performed.
d. Prosthetic ball was placed into scleral husk
Later Clinical Course
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Patient would not leave eye guard in place.
The ophthalmologist subsequently removed
the ball from the scleral husk.
The scleral husk was left in place and will
atrophy.
Question
Any ideas as to what was the underlying
problem with this patient’s eye?
Diagnosis
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Keratoconus
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Corneal hydrops
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Corneal perforation
Keratoconus
Munson’s Sign
Corneal hydrops
Pathology
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Downs Syndrome - - - keratoconus
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Keratoconus - - - corneal hydrops
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Corneal hydrops - - - corneal perforation
What went wrong?
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My lack of knowledge
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Ophthalmology consultation timing
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Ophthalmology
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Patient factors
Cognitive Illusions
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The hot road illusion
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The retrospectroscope:
Hindsight is always 20/20 vision.
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“You can see more by looking.” - Yogi Berra
Diagnostic Errors with Clinical
Heuristics
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Availability heuristic errors
Anchoring errors
Framing errors
Blind obedience
Premature closure
Faulty or inadequate knowledge
Back to the Patient with the Red Eye
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Availability heuristic errors
Anchoring errors
Framing errors
Blind obedience
Premature closure
Faulty or inadequate knowledge
The Swiss Cheese Analogy
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Systems related errors
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Cognitive errors
The Doctor, by Sir Luke Fildes
Words of Wisdom
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There is nothing more humbling than
the practice of medicine.
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Continuing Medical Education
Bibliography
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googleimages.com IMB3641 65 low jpg (picture of corneal hydrops)
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googleimages.com CLS0610 (picture of Munson’s sign)
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Graber ML, Franklin N, Gordon R. Diagnostic Error in Internal Medicine. Arch Intern Med. 2005;165(13):1493-1499. [PMID:16009864].
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Grewal S, Laibson PR, Cohen EJ. Acute hydrops in the corneal ectasias: associated factors and outcomes. Trans AM Ophthalmology
Society 1997; 97:187-203.
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Groopman J. How Doctors Think. 2008. Houghton Mifflin
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http://www.cornea.org (picture of keratoconus)
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MKSAP 15, American College of Physicians
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Redelmeier DA. Improving patient care. The cognitive psychology of missed diagnoses. Ann Intern Med. 2005;142(2):115-120.
[PMID:15657159].
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Rothschild JM, Landrigan CP, Cronin JW, et al. The Critical Care Safety Study: The incidence and nature of adverse events and serious
medical errors in intensive care. Crit Care Med. 2005;33(8):1694-1700. [PMID:16096443].
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Tuft SJ, Gregory, Wm, Buckley RJ. Acute corneal hydrops. Ophthalmology: Oct. 1994:1738-44.
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Vidyarthi A, Arora V, Schnipper J, Wall S, Wachter R. Managing discontinuity in academic medical centers: strategies for a safe and
effective resident sign-out. J Hosp Med. 2006;1(4):257-266. [PMID:17219508].