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contrast, corneal disease and iritis may cause significant blurriness of vision, either from opacification of the cornea (corneal infiltrates) or from inflammatory exudate and cells in the anterior
chamber (iritis).
5—HEAD AND NECK
2. Pupillary Abnormalities
In benign disease, the pupils are normal. Serious causes of the red eye, however, may produce
anisocoria (i.e., unequal pupils, see Chapter 21). Usually, the smaller pupil is in the inflamed eye
(i.e., relative miosis), either f rom inflammatory congestion of the iris itself, associated ciliary muscle spasm, or both. Rarely the pupil of the inflamed eye is larger than that of the contralateral
pupil (relative mydriasis), a finding of acute angle-closure glaucoma, which produces ischemia and
infarction of the iris tissue itself (i.e., the pupillary constrictor muscle).
3. Pupil Constriction Tests
In serious eye disorders, pupillary constriction may be painful, which explains why many affected
patients experience photophobia (i.e., pain during exposure to light). Painful pupillary constriction
is the basis for three different pupillary constriction tests. ese tests differ in how the pupillary
constriction is produced, but in all tests the positive response is pain in the affected red eye.
a. Direct Photophobia Test
e clinician shines a penlight into the affected eye. (See the section on the normal light reflex in
Chapter 21.)
b. Indirect (Consensual) Photophobia Test
e clinician shines a penlight into the contralateral (i.e., uninflamed) eye. (See the section on the
normal light reflex in Chapter 21.)
c. Finger-to-Nose Convergence Test
e patient focuses on his or her outstretched finger and slowly moves the finger toward his or her
nose. (See the section on the near synkinesis reaction in Chapter 21.)
B. DISTINGUISHING BACTERIAL CONJUNCTIVITIS
FROM NONBACTERIAL CAUSES
According to traditional teachings, bacterial conjunctivitis is more likely if disease onset is during
the winter months or if there is a purulent exudate,4 which may cause stickiness of the eyelids in
the morning. Viral conjunctivitis is traditionally thought to be more likely if there is watery discharge, conjunctival follicles, or preauricular adenopathy. Allergic conjunctivitis is suggested by a
stringy mucoid discharge and itchiness of the eyes.
1. Normal Conjunctival Anatomy
e normal anatomy of the conjunctiva appears in Fig. 23.1.
2. Papillary Conjunctivitis vs. Follicular Conjunctivitis
In conjunctivitis, combinations of hyperemia (vasodilation), edema, and hemorrhage produce a
red color, which is most prominent on the undersurface of the lids and the more peripheral portions of the globe (see Fig. 23.2). Some patients develop small projections on the conjunctival sur-
face of the upper and lower lids (the palpebral or tarsal conjunctiva). ese elevations are classified
as papillae or follicles (i.e., papillary conjunctivitis or follicular conjunctivitis, see Fig. 23.2). Papillae
characteristically appear in bacterial or allergic conjunctivitis. Follicles suggest viral or chlamydial
conjunctivitis and are often associated with preauricular adenopathy.
23—THE RED EYE
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187
Conjunctival zones:
Fornix
Bulbar
Palpebral (tarsal)
Cornea
Limbus
Sclera
Fig. 23.1 Normal conjunctival anatomy. The figure compares the frontal view of the normal eye (left) to its
corresponding sagittal section (right). The normal conjunctiva (heavy blue line, right) is a continuous translucent membrane that lines the undersurface of both eyelids (tarsal or palpebral conjunctiva), reflects backwards (at the fornix), and then covers the anterior globe (bulbar conjunctiva). The conjunctiva ends at the
limbus, the peripheral border of the cornea where it joins the sclera.
Limbus
Periphery of globe
Papillary
conjunctivitis
Fig. 23.2 Conjunctivitis: papillary vs follicular. The erythema of conjunctivitis (shaded dark grey) is most
intense on the inside surface of the eyelids (tarsal conjunctiva) and peripherally on the globe (near the fornices), while the erythema is less intense centrally near the limbus. In more severe conjunctivitis, the entire
conjunctival surface (both tarsal and bulbar) is red. This pattern of erythema contrasts with iritis, which causes
more intense erythema centrally around the limbus, a finding called circumlimbal flush or ciliary flush. In
patients with conjunctivitis, the clinician should inspect the everted upper or lower lids, noting whether the
inner membrane has its normal smooth surface or instead has small projections, which are characterized as
either papillae or follicles. In this example, the clinician has used his thumb to gently evert the lower lid for
inspection. Papillae (left bottom) are contiguous red vascular bumps; the center of each papilla contains a
blood vessel. They are red on the surface and pale at the base. Papillae are often so tiny that the conjunctiva
acquires a velvety appearance and only magnification reveals their true nature. Other times, papillae may
become large and produce a cobblestone appearance. Follicles (right bottom) are discrete 1 to 2 mm diameter white bumps consisting of aggregates of lymphoid tissue; the center of each is avascular. They are pale
on the surface and red at the base. See text for the significance of these findings.
Follicular
conjunctivitis
188
LRs
SERIOUS EYE DISEASE
Finger-to-nose convergence
Anisocoria
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5—HEAD AND NECK
III. Clinical Significance
A. DISTINGUISHING SERIOUS FROM BENIGN DISEASE
In 5 studies of 957 consecutive patients with red eye, all 3 pupillary constriction tests increased
probability of serious disease: indirect photophobia test (likelihood ratio [LR] = 28.8;
EBM Box 23.1), finger-to-nose convergence test (LR = 21.4), and direct photophobia test (LR
= 8.3). e absence of pain in the affected eye during the finger-to-nose convergence test decreases
probability of serious disease (LR = 0.3). In these studies, most patients with serious disease had
anterior uveitis (iritis) or corneal disorders (herpes simplex infection, corneal abrasion, and miscellaneous causes of keratitis). e presence of anisocoria is also helpful: anisocoria with the smaller
pupil in the affected red eye (relative miosis) increased probability of serious disease (LR = 6.5),
and anisocoria with the larger pupil in the affected red eye (relative mydriasis) was diagnostic of
acute glaucoma (LR = 57.6).
EBM BOX 23.1 The Red Eye, Diagnosing Serious Eye Disease*
Sensitivity
Finding (Reference)
Detecting serious eye disease
Direct photophobia
Indirect photophobia
Finger-to-nose
convergence test
Anisocoria with smaller
pupil in red eye
(difference >1 mm)
Detecting acute angle closure glaucoma
Anisocoria with larger
pupil in red eye
*Diagnostic standard: for serious eye disease, slit-lamp biomicroscopy revealing iritis, keratitis,
corneal abrasion, scleritis, or acute narrow angle glaucoma.
†
Definition of findings: for pupillary constriction tests (direct photophobia, indirect photophobia,
finger-to-nose convergence test), see text.
‡
Likelihood ratio (LR) if finding present = positive LR; LR if finding absent = negative LR.
§
All of the patients with acute glaucoma in this study had a mydriatic pupil (i.e., sensitivity = 100%);
for calculations of the LRs, 0.5 was added to all cells of the 2 × 2 table.
†
(%)
5–7
5
8
10
54–77 80–98 8.3 0.4
44 98 28.8 0.6
74 97 21.4 0.3
19 97 6.5 0.8
9
§
90
Specificity
(%)
98 57.6 NS
Likelihood Ratio‡ if Finding Is
Present Absent
Probability
Decrease Increase
+45%+30%+15%–15%–30%–45%
0.1 0.2 0.5 12510
LRs
Negative finger-to-nose
Indirect photophobia
convergence test
test
Direct photophobia
23—THE RED EYE
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EBM BOX 23.2 Conjunctivitis, Diagnosing Bacterial Etiology*
Likelihood Ratio‡
if Finding Is
Present Absent
Finding (Reference)
Redness of conjunctiva
Peripheral only
Red eye observed at 20 feet
Redness completely obscures tarsal
vessels
Discharge
14,15
†
12,13
14
14
Sensitivity
(%)
30 59 NS NS
94 36 1.5 0.2
33 93 4.6 NS
Specificity
(%)
None 12–28 41–56 0.4 …
Watery 6–12 … NS …
Mucous 6–44 … NS …
Purulent 32–50 85–94 3.9 …
Follicular conjunctivitis
Papillary conjunctivitis
Preauricular adenopathy
*Diagnostic standard: for bacterial conjunctivitis, recovery of a known pathogen from conjunctival
secretions (i.e., Streptococcus pneumonia, Hemophilus influenzae, Moraxella catarrhalis, or
Staphylococcus aureus).
†
Definition of findings: for follicular and papillary conjunctivitis, see Fig. 23.2.
‡
Likelihood ratio (LR) if finding present = positive LR; LR if finding absent = negative LR.
NS, Not significant.
15
15
14,15
50 48 NS NS
24 95 NS NS
6–16 70–88 NS NS
BACTERIAL CONJUNCTIVITIS
Probability
Decrease Increase
+45%+30%+15%–15%–30%–45%
LRs
0.1 0.2 0.5 12510
189
LRs
Absence of red eye at 20 feet
In general, the sensitivity of other classic findings is poor: 23% to 56% of patients with serious
pathology lack photophobia, and 81% lack anisocoria. Also, even though abnormal visual acuity is
a clue to serious eye disease, up to half of patients with proven iritis have a visual acuity of 20/60 or
better.11 e clinician should never use the finding of normal visual acuity as an argument against
serious eye disease.
B. DISTINGUISHING BACTERIAL CONJUNCTIVITIS FROM
NONBACTERIAL CAUSES
1. Individual Findings
In the 3 studies enrolling 281 consecutive patients with conjunctivitis summarized in EBM
Box 23.2, investigators excluded patients with previous eye trauma, eye surgery, chemical injury,
visual blurring, contact lenses, conspicuous iritis (circumlimbal flush), or obvious deep orbital
pathology. In these studies, the presence or absence of matting of the eyes was the most helpful
Redness obscures tarsal vessels
Purulent discharge
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5—HEAD AND NECK
historical item: matting of both eyes in the morning increased probability of bacterial conjunctivitis (LR = 2.6), and absence of matting in both eyes decreased it (LR = 0.3).
12,13
Two physical findings increased probability of bacterial conjunctivitis: complete redness of
the conjunctiva obscuring the tarsal vessels (LR = 4.6, EBM Box 23.2) and observed purulent
discharge (LR = 3.9). Absence of red eye when observed at 20 feet decreased probability of
a bacterial cause (LR = 0.2). e symptoms of itching or burning and the findings of preauricular adenopathy, conjunctival follicles, or conjunctival papillae were diagnostic unhelpful
(LRs not significant).
12,13,15
Finally, even though the physical sign of purulent secretions was
accurate, the patient’s report of “purulent” secretions was diagnostically unhelpful (LR not
significant).
2. Combined Findings
One study of 700 patients16 demonstrated that eye specialists using combinations of bedside findings could accurately diagnose the cause of conjunctivitis. e diagnostic standard in this study
was cytology and cultures of conjunctival secretions: bacterial conjunctivitis was defined by positive bacterial culture and neutrophils; viral conjunctivitis by positive viral inclusions, mononuclear
cells and negative bacterial cultures; and allergic conjunctivitis by conjunctival eosinophils. e
clinicians based the diagnosis of bacterial conjunctivitis on the findings of mucopurulent drainage
and absence of follicles and adenopathy: this combination of findings accurately detected a bacterial cause (positive LR = 5.3; negative LR = 0.2). Combinations of scanty watery discharge, follicles, and preauricular adenopathy accurately diagnosed a viral cause (positive LR = 3.5; negative
LR = 0.4). Finally, combinations of allergic chemosis (a pale swollen conjunctiva with a jelly-like
appearance) and stringy mucoid discharge indicated an allergic cause (positive LR = 16.4, negative LR = 0.01). Still, it is unclear from the study how these experienced clinicians specifically
combined each of these findings to achieve such spectacular accuracy.
References may be accessed online at Elsevier eBooks for Practicing Clinicians.
References
https://t.me/medicina_free
1. Rose P. Management strategies for acute infective conjunctivitis in primary care: a systematic review.
Expert Opin Pharmacother. 2007;8(12):1903–1921.
2. Duke-Elder S. Inflammation of the Uveal Tract: Uveitis. System of Ophthalmology. Diseases of the Uveal
Tract. Mosby; 1966:39.
3. Feibel RM. Fred Loe, MD, and the history of trachoma. Arch Ophthalmol. 2011;129(4):503–508.
4. Narayana S, McGee S. Bedside diagnosis of the ‘red eye’: a systematic review. Am J Med.
2015;128(11):1220–1224.
5. Au Y, Henkind P. Pain elicited by consensual pupillary reflex: a diagnostic test for acute iritis. Lancet.
1981;2(8258):1254–1255.
6. Chong NVH, Murray PI. Pen torch test in patients with unilateral red eye. Br J Gen Pract. 1993;43(371):259.
7. Yaphe J, Pandher KS. e predictive value of the penlight test for photophobia for serious eye pathology
in general practice. Fam Pract. 2003;20(4):425–427.
8. Talbot EM. A simple test to diagnose iritis. Br Med J (Clin Res Ed). 1987;295(6602):812–813.
9. Rose GE, Pearson RV. Unequal pupil size in patients with unilateral red eye. Br Med J. 1991;302(6776):
571–572.
10. Timlin H, Butler L, Wright M. e accuracy of the Edinburgh Red Eye Diagnostic Algorithm. Eye
(Lond). 2015;29(5):619–624.
11. Durrani OM, Tehrani NN, Marr JE, Moradi P, Stavrou P, Murray PI. Degree, duration, and causes of
visual loss in uveitis. Br J Ophthalmol. 2004;88(9):1159–1162.
12. Rietveld RP, ter Riet G, Bindels PJE, Sloos JH, van Weert HC. Predicting bacterial cause in infec-
tious conjunctivitis: cohort study on informativeness of combination of signs and symptoms. BMJ.
2004;329(7459):206–210.
13. van Weert HC, Tellegen E, Ter Riet G. A new diagnostic index for bacterial conjunctivitis in primary
care. A re-derivation study. Eur J Gen Pract. 2014;20(3):202–208.
14. Zegans ME, Sanchez PA, Likosky DS, et al. Clinical features, outcomes, and costs of a conjunctivitis
outbreak caused by the ST448 strain of Streptococcus pneumoniae. Cornea. 2009;28(5):503–509.
15. Fitch CP, Rapoza PA, Owens S, etal. Epidemiology and diagnosis of acute conjunctivitis at an inner-city
hospital. Ophthalmology. 1989;96(8):1215–1220.
16. Stenson S, Newman R, Fedukowicz H. Laboratory studies in acute conjunctivitis. Arch Ophthalmology.
1982;100(8):1275–1277.
190.e1
CHAPTER
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24
Hearing
KEY TEACHING POINTS
• Hearing loss is a common problem in older patients, one often overlooked unless specific
testing is performed.
• Three bedside tests accurately detect hearing loss: the whispered voice test, finger rub
test, and ticking watch test.
• Once hearing loss is identified, tuning fork tests (i.e., Weber and Rinne test) help
distinguish neurosensory from conductive hearing loss. The finding of bone conduction
greater than air conduction (during the Rinne test) greatly increases probability of a
conductive hearing loss.
Introduction
I.
Hearing loss, which affects approximately 50% of all individuals over the age of 65, is associated
with difficulty communicating and higher rates of depression, frailty, and falls.
casual assessment in the office overlook significant hearing loss about half the time.
hearing loss are either neurosensory (i.e., damage to the auditory nerve or cochlear hair cells) or
conductive (i.e., damage to the parts of the ear that conduct sound from air to the cochlea). Most
neurosensory hearing loss is due to presbycusis (the degenerative hearing loss of aging). Less common causes are Meniere disease and acoustic neuroma. e most common causes of conductive
loss are impacted cerumen, otitis media, perforated eardrum, and otosclerosis.
II.
Technique
A.
WHISPERED VOICE TEST
Many tests of hearing are available to general clinicians, some more formal (hand-held audiometer)
than others (listening to a whispered voice or to a watch, finger rub, or tuning fork). One validated
test not requiring special tools is the whispered voice test. In this test, the clinician whispers a combination of three letters or numbers (e.g., 5, B, 6) while standing at arm’s length (i.e., approximately
2 feet) behind the patient and then asks the patient to repeat the sequence. If the patient answers
correctly, hearing is considered normal and testing is stopped. If the patient misidentifies any of the
three items, the clinician repeats different triplets of numbers or letters 1 or 2 more times. If 50% or
more of the items in the two or three triplets are incorrect, the test is abnormal.
e clinician stands behind the patient to prevent lip-reading. Only one ear is tested at a time,
the other being masked by the examiner’s finger, which occludes the external auditory canal and
makes continuous circular rubbing motions (occlusion without rubbing is insufficient masking).
e clinician should quietly exhale before whispering to produce the quietest whisper possible.
1
Clinicians using
2
e causes of
1
3
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Fig. 24.1 Finger rub test. In this illustration the clinician is testing the patient’s right ear, and the patient indi-
cates by raising the right arm that the sound of the finger rub is perceived (i.e., “test negative,” defined as the
patient can hear the finger rub). In the original study of this finding,4 each ear was tested 3 times (with both
faint and strong stimuli), and “cannot hear finger rub” was defined as failure to hear any of the three stimuli.
Because the patient must raise the arm indicating the side the stimulus is heard, masking the untested ear is
unnecessary (i.e., if the right ear is being tested in a patient with severe unilateral right hearing loss, the clinician will be able to detect that the unmasked left ear is detecting the sound because the left arm is raised).
5—HEAD AND NECK
B. FINGER RUB TEST
e clinician stands directly in front of the patient with outstretched arms and tests one ear at a
time by rubbing thumbs against the distal fingers (Fig. 24.1).4 During the test the patient has the
eyes closed and is encouraged to listen carefully to indicate which side the rubbing is heard by
raising the ipsilateral arm. A strong finger rub is as loud as the clinician can muster without snapping the fingers; a faint rub is the softest the clinician can still hear. Inability to hear the finger
rub is “test positive.”
C. TICKING WATCH TEST
e clinician positions a ticking watch 6 inches away from the patient’s ear while the patient
occludes the opposite ear. e test is repeated 6 times, and inability to hear the ticking sound during any of these trials is a positive test.5 To prevent providing visual clues, the clinician should test
the patient from behind or ask the patient to close his or her eyes.
D. TUNING FORK TESTS
1. Introduction
After hearing loss is identified, tuning forks tests distinguish neurosensory from conductive loss.
All tuning fork tests are based on the same fundamental principle, discovered almost 500 years
ago,* that sound conducts preferentially through bone to ears with disease causing conductive
* e Italian physician Capivacci made this discovery after connecting his subject’s teeth to a zither and then
plucking the zither’s strings.
6
24—HEARING
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193
hearing loss. Tuning fork tests were introduced into clinical otology in the early 1800s, and at one
time there were over 15 distinct tuning fork tests.7 After introduction of audiometry, however,
enthusiasm for tuning fork tests waned, and now only two are commonly used, the Weber and
Rinne test.
2. The Frequency of the Tuning Fork
Most authorities recommend using the 512-Hz tuning fork for tuning fork tests,8 because
frequencies above 512-Hz detect conductive hearing loss less well and because frequencies of
128-Hz or lower generate so many vibrations that even patients without hearing can sense them.
9–11
e 512-Hz fork is preferred to the 256-Hz fork, because the 256-Hz fork produces more falsepositive results in some studies.
12,13
3. Method of Striking the Fork
Most authorities recommend striking the fork against a soft surface, such as a rubber pad or the
muscles of the forearm.8 e principal tone produced is the same whether the tines are struck on
a soft or harder surface, but the harder surface generates multiple overtones that may confound
interpretation by the patient.
7,14
Weights, sometimes added to the tines to minimize overtones,
also shorten the time of vibration and are not recommended.
4. Weber Test
In the Weber test, the clinician strikes the fork, places it in the middle of the patient’s vertex,
forehead, or bridge of nose, and asks “Where do you hear the sound?” (Fig. 24.2). In patients with
unilateral hearing loss, the sound is preferentially heard in the good ear if the loss is neurosensory
and in the bad ear if the hearing loss is conductive.
8,15
Weber himself recommended placing the
vibrating fork on the incisors,16 and subsequent studies do show that this is the most sensitive
technique,17 although concerns of transmitting infectious diseases now prohibit this method.
According to traditional teachings, persons with normal hearing perceive the sound in the
midline or inside their head, but studies show that up to 40% of normal-hearing persons also
lateralize the Weber test.11 erefore, the Weber test should be interpreted only in patients with
hearing loss.
e hum test is often used to simulate the Weber test, particularly when clinicians are concerned about a unilateral conductive hearing loss and tuning forks are unavailable (e.g., the clinician may be discussing symptoms with a patient over the telephone).18 e patient is asked to hum
a sustained pitch for a few seconds and then note whether the sound is more pronounced on the
right or left side or perceived equally. In patients with conductive loss, the sound should be more
pronounced in the bad ear.
†
5. Rinne Test
In the Rinne (pronounced “RIN-neh”) test, the clinician tests each ear individually to determine whether that ear detects sound better through air or bone (Fig. 24.2). Air conduction
(AC) is tested by holding the vibrating fork about 2.5 cm away from the ear, traditionally with
the axis joining the tips of the tines in line with the axis through both external auditory canals.
Bone conduction (BC) is tested by holding the stem of the vibrating fork against the mastoid
(excessive force should be avoided because it diminishes the test’s specificity).19 ere are two
methods for comparing AC and BC: (1) loudness comparison technique, in which the fork is
held about 2 seconds in each position and the patient indicates which position is louder, and
(2) threshold technique, in which the clinician uses a stopwatch to time how long the patient
†
Clinicians can simulate this by plugging one of their own ears with a finger (thus creating a conductive
hearing loss) and then humming a sustained pitch. e sound will be more pronounced in the plugged ear.
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WEBER TEST RINNE TEST
Air conduction
"Where do you hear the sound?"
Bone conduction
Fig. 24.2 Weber and Rinne tuning fork tests. In the Weber test (left), the clinician holds the vibrating tuning
fork in the midline against the patient’s vertex, forehead, or bridge of nose and asks “Where do you hear the
sound?” In the Rinne test (right), the clinician tests one ear at a time, comparing perception of sound conducted
through air (top right) to perception of sound conducted through bone (bottom right). When testing air conduc-
tion, the tuning fork is held so that an axis through both external auditory canals (dashed line) passes through
both tines of the fork. When testing bone conduction, the stem of the vibrating fork is held against the mastoid.
5—HEAD AND NECK
hears the sound, from the moment the fork is struck to when the sound disappears, first for AC
and then BC.
8
Patients with normal hearing or neurosensory hearing loss perceive sound better (i.e.,
louder or longer) through AC than through BC, whereas those with conductive hearing loss
perceive
it better through BC. According to a confusing tradition, the finding of
than AC is recorded “Rinne negative,” although it is more explicit to record “BC > AC” for the
abnormal result.
e orientation of the tines of the fork affects the performance of the air conduction portion
of the Rinne test. Traditionally, the tuning fork is held so that an axis through both ears passes
through both tines of the fork (“parallel orientation”; Fig. 24.2), although a “perpendicular orien-
tation” is also commonly used.
perpendicular orientation,
20
but as long as a consistent technique is employed the accuracy of
the Rinne test is the same whether a parallel or perpendicular orientation is used.
oblique orientations of the tines should be avoided, because sound waves emanate in two directions from the fork, one direction parallel to the axis of the tines and the other perpendicular to
it. If the tines are held at an oblique angle, these sound waves may actually cancel each other out
and markedly diminish the sound.
the stem of a vibrating fork near their own ear, noting that the sound intermittently disappears.)
Table 24.1 presents examples of different Weber and Rinne test results and possible interpretations.
BC better
20
e parallel orientation produces a louder sound than does the
21
In contrast,
7
(Clinicians can easily convince themselves of this by rotating
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