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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_2572_Библиотеки_им_академика_М_И_Перельмана
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The physical examination • 183
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open or latent (phoria) if revealed only by covering one eye. In
addition, they can be conc om itan t (where the angle of squint
remains the same in all positions of gaze) or incomitant (where
the angle of squint deviation is greatest in a single position of
gaze). The latter is comm on ly the result of extraocular muscle
paralysis.
Detection of a squint
Examination sequence
Fig. 8.13 Testing the central visual field. Sit facing the patient, 1 metre
away. Present a red target at a point equidistant between yourself and the
patient in the periphery, starting when you can first see the target as red. Bring
the target inwards in the direction of the blue arrows, asking the patient to alert
you when they first see the target as red. Test each eye separately.
• Check all four quadrants, testing each eye separately.
• To assess very early visual field loss, repeat the same test
using a red hatpin or a red Neurotip (Fig. 8.13).
• It is important to sho w the patient the red target and ask
them to report what colour they see. A dull or pale red
suggests colour desaturation, which may indicate optic
nerve dysfunction.
• When testing each quadrant with a red target, be sure to
explain to the patient that they should say when they first see
that the target is red and not when they first see it. The target
may be visualised before they appreciate the red colour.
• To test the blind spot, place a red-tipped target equidistant
between the patient and yourself at the visual fixation point.
• Move the target temporally from central fixation until it
disappears.
• Once you have identified the blind spot, move the target
slowly up and down and side to side until it reappears. This
allows you to compare the patient’s blind spot with yours.
Ocular alignment and eye movements
The eyes normally move in the same direction (conjugate
motion) in all positions of gaze except during convergence. Any
misalignment is referred to as a squint (strabismus). Squints
are described as ma nif est (tropia) if present wit h both eyes
• Sit directly facing the patient, approximately 1 metre away
and at a similar height.
• Check visual acuity as part of the examination.
• Look for any abnormal head posture, such as head tilts (seen
in cranial nerve IV palsy) or head turns (cranial nerve VI palsy).
These signs may be subtle.
• Hold a pen torch directly in front of the patient and instruct
them to look at the light. Observe the reflection of the light on
the cornea in relation to the pupil. The reflections should be
symmetrical between the two eyes. Ask the patient if they see
a single or double light. If they see double, this may indicate
the presence of a squint, but not seeing double does not
exclude a squint. If the reflection is on the nasal aspect of the
pupil in one eye, this suggests that the eye is deviated outwards and is described as an exotropia.
• To confirm the presence of a squint, perform the cover/un-
cover test:
• Ask the patient to look at the pen torch at all times and
then cover one eye.
• Look at the uncovered eye for any movement. It may be
helpful to repeat this several times.
• Inward movement of the uncovered eye suggests that it
was positioned abnormally outwards and is described as
an exotropia (divergent manifest squint).
• Conversely, if the eye moves outwards when the contra-
lateral eye is covered, this suggests that it was abnormally
positioned inwards and is described as an esotropia
(convergent manifest squint).
• Repeat the cover/uncover test for the other eye.
• Failure of an eye to move despite an obvious corneal light
reflex may indicate that the eye has such poor vision that it
cannot take up fixation or else it is restricted from moving.
• The alternating cover test involves covering the eyes alter-
nately and quickly while the patient is fixated on the pen
torch. Leave the cover on each eye for about 2 seconds but
move between the eyes in less than 1 second. The movement is repeated multiple times. This test will help to elicit
latent squint.
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184 • THE VISUAL SYSTEM
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Ocular movements
Examination sequence (Video 17E)
• In the same seating position, ask the patient to look at a
target or pen-torch light about 50 cm away.
• Ask them to say if and when they experience diplopia.
• Starting from the primary position, move the target in the six
positions of gaze (see Fig. 8.9) and up and down.
• If diplopia is present, ask whether this is horizontal, vertical or
a combination of the two, and determine where the image
separation is most pronounced.
• Look for nystagmus and determine whether the eye move-
ment is smooth.
Interpretation of any limitation of excursion is mad e by
reference to the functions of the extraocular muscles (see
Fig. 8.2).
Oculocephalic (doll’s-eye) reflex
• This reflex is the ability of the eyes to remain fixated while the
head is turned in the horizontal plane (Fig. 8.14). An impaired
reflex indicates a brainstem abnormality. This test can also be
performed on an unconscious patient to check for brainstem
function.
Examination sequence
• With the patient supine, ask them to look at your face. Gently
turn their head from side to side, noting the eye movements.
Nystagmus
Nystagmus is continuous, uncontrolled movement of the eyes.
Biphasic or jerk nystagmus is the most common type. It is
characterised by slow drift in one direction, followed by fast
correction/recovery in the opposite direction. The direction of the
fast phase designates the direction of the nystagmus. If there are
equal oscillations in both directions, it is called pendular
nystagmus.
Nystagmus commonly indicates vestibular disease, and the
examination sequence and differential diagnosis are covered on
page 197.
Ophthalmoscopy
The direct ophthalmoscope is a useful tool for assessing both the
anterior and the posterior segments of the eye. Pharmacological
pupil dilatation is essential for a thorough fundus examination,
though the optic disc can be examined sufficiently without
dilatation.
Fig. 8.14 Oculocephalic reflex. Move the head in the horizontal plane. Note that the eyes move in the opposite direction to head movement.
The physical examination • 185
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Examination sequence (Video 17F)
• Ask the patient to look at a distant target.
• When using the direct ophthalmoscope to examine the pa-
tient’s right eye, hold the ophthalmoscope in your right hand
and use your right eye to examine. Hold it in your left hand
and use your left eye to examine the patient’s left eye.
• Place your free hand on the patient’s forehead and brow, as
this will steady the head and improve your proprioception
when moving closer to the patient with the ophthalmoscope.
• Rotate the ophthalmoscope lens to þ10. This will allow a
magnified view of the anterior segment. Examine the eyelid
margins, conjunctiva, cornea and iris. If epithelial defects are
suspected, fluorescein can be administered and a cobalt blue
filter used to highlight the epithelial defect.
• To examine the fundus, dial the lens back to 0.
• With your hand on the forehead and the brow, use the
ophthalmoscope to see the red refl ex (red light reflected off
the retina) at a distance of about 10 cm. When the red reflex
is in focus, look for opacities and determine whether they are
static or mobile. Static opacities are usually due to cataract,
while mobile opacities indicate vitreous opacities.
• Slowly move the ophthalmoscope closer to the patient
almost to the point that your forehead touches your thumb,
which is resting on the patient’s forehead and brow (see
Fig. 8.15).
• Turn the lens dial until the optic disc comes into focus; if it
does not, focus on a blood vessel.
• The optic disc can usually be located easily; if not, follow a
blood vessel centrally (in the direction opposite to its
branches) to locate it.
• Examine the optic disc, paying particular attention to its
shape, colour, edges and cup size.
• Follow each blood-vessel arcade and examine each of the
retinal quadrants.
• To examine the macula, ask the patient to look directly at the
light.
The normal retina looks different in Asian and Caucasian pa-
tients (Fig. 8.16).
8
Fig. 8.15 Ophthalmoscopy. Ask the patient to focus on a distant target. To
examine the left eye, use your left eye to look through the ophthalmoscope
and left hand to hold it, index finger on the wheel. Hold the patient’s head with
your free hand. Gradually move in to visualise the optic disc. Rotate the wheel
to obtain a clear, focused image.
A
B
Fig. 8.16 The normal fundus. A Caucasian. B Asian.
186 • THE VISUAL SYSTEM
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8.10 Causes of optic disc swelling
Unilateral Clinical features
Optic neuritis
Arteritic anterior ischaemic optic neuropathy
Non-arteritic anterior ischemic optic
neuropathy
Lyme disease
Bartonella infection
Other neuroretinitis (syphilis, tuberculosis,
toxocara, sarcoid)
Optic nerve glioma
Optic nerve head metastases
Bilateral Clinical features
Papilloedema
Optic disc drusen
Diabetic papillitis
Pseudopapilloedema in hypermetropes
Hypertensive papillopathy
• Onset over 1–2 weeks days, recovery starts after 1–3 months
• Reduced colour vision
• Orbital pain
• Relative afferent pupillary defect
• Associated with multiple sclerosis
• Sudden onset visual loss
• Associated features of giant cell arteritis (scalp tenderness, jaw claudication, fever)
• Optic disc rapidly becomes chalky white
• Age usually >50
• Usually causes loss of superior or inferior hemi-field
• Painless
• Associated cardiovascular risk factors (hypertension, diabetes, poor lipid profile)
• Recent tick bite
• Erythema chronicum migrans
• Associated uveitis, cardiovascular or neurological deficits
• Recent history of cat scratch
• Pustules at site of cat contact
• New lymphadenopathy
• May show neuroretinitis with subretinal fluid and a macular star
• May present with unilateral optic disc swelling and macular star without systemic features of disease
• History of neurofibromatosis type 1
• May be associated with proptosis
• History of malignancy
• Headache
• Nausea/vomiting
• Pulsatile tinnitus
• Transient visual obscurations
• Enlarged blind spot on testing
• Usually asymptomatic
• Yellow or white bodies at the optic disc head
• Confirmed by autofluorescence imaging or ocular ultrasound
• History of diabetes
• Vision relatively spared compared to optic disc examination
• Diabetic retinopathy (microaneurysms, exudates, blot haemorrhages and neovascularisation)
• Positive refraction
• Short axial length confirmed by ocular ultrasound
• History of hypertension
• Headaches
• Blurred vision
• Hypertensive retinopathy (cotton wools spots, hard exudates and flame shaped haemorrhages)
Swelling of the optic disc is a very important clinical sign.
Causes of unilateral and bilateral optic disc swelling, and their
distinguishing features, are summarised in Box 8.10.
A variety of diseases that can damage the optic nerve cause
an abnormally pale optic disc (see Fig. 8.8D). The differential
diagnosis of optic disc pallor is summarised in Box 8.11.
Retinopathies
Diabetes mellitus leads to a wide range of important abnormalities in the retina, which are summarised in Fig. 8.17.
Hypertension also results in retinal changes (Fig. 8.18). The
retinal arteries are effectively arterioles. Chronic arteriosclerosis
8.11 Differential diagnosis of optic disc pallor
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Type Clinical features
Inherited – Congenital optic
atrophy
End-stage glaucoma
Trauma
Compressive
Orbital cellulitis
Orbital neoplasm
Thyroid eye disease
Neurological
End-stage papilloedema
Metabolic
Diabetes mellitus
Nutritional deficiency
Toxic amblyopia
Ethambutol
Sulphonamide
Vascular
Central retinal artery occlusion
(CRAO)
Anterior ischaemic optic
neuropathy (AION)
Inflammatory
Meningitis
Retrobulbar neuritis
• Present from birth or young age
• May have family history
• Progressive loss of visual fields with reduced acuity
• Optic disc cupped in addition to pallor
• History of trauma resulting in decreased vision
• Acute proptosis with periocular inflammation and swelling
• Pyrexia and signs of sepsis
• Reduced ocular movements
• Unilateral proptosis
• Reduced vision in late stages
• Progressive proptosis with gradual loss of vision
• May have reduced ocular movements
• History of malignancy (e.g. breast, prostate, lymphoma)
• Unilateral or bilateral proptosis
• Lid retraction, unable to close eye
• Conjunctival chemosis and hyperaemia (acute disease)
• Reduced eye movements
• Reduced vision (late)
• Bilateral optic disc swelling with pallor.
• Headache and nausea
• Visual obscuration not uncommon
• Occasionally pulsatile tinnitus.
• Enlarged blind spot
• Metabolic and nutritional causes are bilateral
• Associated with gradual decline in vision
• Detailed history and examination essential
• History of sudden painless loss of vision
• Associated cardiovascular disease, including atrial fibrillation or carotid bruit
• Occasionally results from giant cell arteritis
• Sudden painless loss of vision.
• May show altitudinal loss of visual field (either top or bottom half of visual field reduced)
• History of headache
• Photophobia
• Severely ill with signs of sepsis
• Retrobulbar pain worsened by eye movement
• Slight or profound visual loss – usually recovers over weeks
• Optic nerve changes not immediate; take time to develop
The physical examination • 187
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leads to vessel-wall thickening and hyalinisation that appears as
widening of the arterioles, arteriovenous nicking where arterioles
cross venules and a ‘silver and copper wiring’ light reflex.
More acute changescan alsobe seen in malignant hypertension.
Various grading systems have been created to try to link retinal
findings to end-organ damage. The retinal appearances in hypertension are classified using the Modified Scheie classification:
• Grade 0: no changes
• Grade 1: barely detectable arteriolar narrowing
• Grade 2: obvious retinal arteriolar narrowing with focal
irregularities
• Grade 3: grade 2 plus retinal haemorrhages, exudates,
cotton-wool spots or retinal oedema
• Grade 4: grade 3 plus optic disc swelling.
Inherited retinopathies result from a wide range of genetic
mutations. The most common inherited retinopathy is retinitis
188 • THE VISUAL SYSTEM
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AB
C
E
D
F
Fig. 8.17 Retinal abnormalities in diabetes mellitus. A Diabetic maculopathy with yellowish hard exudates near the fovea and macular blot haemorrhages.
B Background diabetic retinopathy: dot and blot haemorrhages and a cotton wool spot in the macula. C Severe non-proliferative diabetic retinopathy: dot and
blot haemorrhages in all quadrants, intraretinal microvascular abnormalities superotemporally and scattered cotton wool spots.
nopathy with extensive neovascularisation at the disc. E Proliferative diabetic retinopathy: vitreous haemorrhage and circinate hard exudates in the macula. F
Treated proliferative diabetic retinopathy: pigmented scars from panretinal laser photocoagulation and persistent haemorrhage in a regressed neovascular
complex inferotemporally.
pigmentosa, which causes symptoms of nyctalopia (difficulty
seeing in dim light) and tunnel vision. Examination reveals a pale
optic disc, attenuated arterioles and bone-spicule retinal
pigmentation (see Fig. 8.8E).
Investigations
Appropriate initial tests for a variety of common presenting eye
problems are summarised in Box 8.12.
D Proliferative diabetic reti-
Ophthalmic examination and COVID-19 • 189
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AB
8
CD
Fig. 8.18 Hypertensive retinopathy. A Increased reflectance, giving a silver wiring appearance to the arteriole (arrow). B Focal arteriolar narrowing (double
arrows) seen in grade 2 disease.
swollen optic disc and macular exudate.
Ophthalmic examination and COVID-19
Ophthalmic examination requires close proximity, infectious patients may be asymptomatic and infection can occur through not
only the oral and nasal mucosa but also the ocular surface.
Ophthalmic examination, therefore, poses a relatively high risk of
transmission of COVID-19 to both patient and examiner. To minimise risk, every patient should be treated as potentially COVID-19
positive and staff should be tested for infection regularly.
Precise advice on personal protective equipment will depend
on local prevalence and policy, but the following is a reasonable
minimum:
C Exudates and flame haemorrhages in grade 3 retinopathy. D Signs of malignant hypertension in grade 4 disease with a
• Wash hands with soap and water or 70% alcohol before and
after seeing patients.
• Wipe down equipment before and after each encounter.
• Patients should wear three-ply surgical face masks
covering their mouth and nose. Patients known to be
infected should wear N95 masks or equivalent to prevent
aerosolised spread.
• Clinical examiners should wear a three-ply surgical face mask
covering their mouth and nose and goggles or face shields to
prevent ocular surface transmission.
• Minimise the time spent in proximity to patients.
190 • THE VISUAL SYSTEM
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8.12 Investigations
Investigation Indication
Clinic tests
Refraction Refractive error, cataract and corneal disorders
Fluorescein staining Corneal epithelial disease
Schirmer’s test Dry eyes, Sjögren’s syndrome
Nasolacrimal duct washout Watery eyes
Blood pressure Hypertensive retinopathy, retinal vein occlusion
Bacterial culture and sensitivity Bacterial conjunctivitis
Viral swab Viral conjunctivitis
Blood tests
Erythrocyte sedimentation rate, C-reactive protein Vasculitis, including giant cell arteritis
Antinuclear antibody Systemic lupus erythematosus
Rheumatoid factor Scleritis
Fasting glucose Diabetic retinopathy
Anti-acetylcholinesterase receptor antibody Myasthenia gravis
Quantiferon Uveitis
Serum angiotensin-converting enzyme Uveitis
Human immunodeficiency virus serology Vasculitis, uveitis
Syphilis serology Unexplained pathology and uveitis/vasculitis
Thyroid function tests Thyroid eye disease
Radiology
Chest x-ray Sarcoidosis/tuberculosis
Orbital ultrasound Incomplete fundal view
Optical coherence tomography Macular disease, glaucoma
Fundus fluorescein angiography Diabetic retinopathy, retinal vein occlusion
Computed tomography of brain and sinuses Orbital cellulitis, thyroid eye disease, intracranial tumours, orbital compressive disease
Magnetic resonance imaging of brain and orbits Pituitary tumour, compressive lesion
Carotid Doppler ultrasound Carotid artery stenosis in ocular ischaemic syndrome or retinal artery occlusion
Invasive tests
Lumbar puncture Idiopathic intracranial hypertension, inflammatory orbital neuropathies
Temporal artery biopsy Giant cell arteritis
Ophthalmic examination and COVID-19 • 191
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OSCE example 1: Gradual visual loss
Mrs. Rahman, 55 years old, presents with a gradual reduction of vision over the last 6 months in both eyes. She says that she also has distortion in her vision
when she is looking at straight lines. In addition, she feels constantly thirsty and is passing urine frequently.
Please examine this patient’s eyes
• Introduce yourself and clean your hands.
• Perform a general inspection, looking for any signs of squint. Check the bedside for any clues that the patient wears glasses.
• Assess visual acuity using a Snellen chart at the appropriate distance.
• Examine the eyes, looking for any conjunctival injection, chemosis or swelling.
• Dim the room lights.
• Test the pupillary light reflexes.
• Ideally, dilate the pupils at this stage.
• Test the red reflex in each eye.
• Dial the fundoscope to þ 10 and examine the anterior portion of the eye, including the lens.
• Dial the fundoscope back to 0 and examine the fundus, looking at the disc and superior, nasal, inferior and temporal fundus.
• Finally, inspect the macula.
• Thank the patient and clean your hands.
Summarise your findings
Visual acuity is reduced to 6/18 in both eyes, and fundoscopy reveals multiple retinal haemorrhages and exudates which include changes at the macula.
Suggest a diagnosis
The most likely diagnosis is diabetic retinopathy with diabetic maculopathy.
Suggest initial investigations
Urine dipstick, fasting blood glucose, and blood pressure.
Advanced level comments
Diabetic macular oedema is the most common cause of reduced vision in diabetic patients. It may result in distortion, making straight lines appear bent.
8
OSCE example 2: Double vision
Mr. Penrose, 75 years old, presents with double vision that has increased rapidly over the last week. He says that not only do objects appear side by side but also that
the two images are separated vertically. He feels that his eyelid is drooping on his left side. He constantly has to lift his eyelid to see out of his left eye.
Please examine the patient’s eye movements
• Introduce yourself and clean your hands.
• Perform a general inspection: look for ptosis and squint, and examine the bedside for any spectacles that may contain a prism.
• Inspect visual acuity in each eye.
• Dim the room lights.
• Test pupillary light reflexes.
• Test all eye movements for ophthalmoplegia.
• Examine the optic nerve using an ophthalmoscope.
• Examine cranial nerves I, V, VI, VII, VIII, IX, X, XI and XII.
• Thank the patient and clean your hands.
Summarise your findings
The patient has a partial ptosis on the left with a dilated pupil. Eye movements are diminished with impaired adduction and elevation of the eyeball. Double
vision is confirmed on testing of eye movements.
Suggest a diagnosis
The most likely diagnosis is left incomplete III nerve palsy (complete palsy would cause total ptosis with relief of double vision).
Suggested investigations
Fasting glucose and cholesterol, blood pressure, erythrocyte sedimentation rate and a magnetic resonance angiogram to check for an underlying cerebral
artery aneurysm.
Advanced level comments
Palsies of the III nerve result in ptosis and diplopia. Microvascular damage to the III nerve usually spares the pupil. Compressive lesions, such as an aneurysm,
cause a dilated pupil (as pupillary fibres are located on the outside of cranial nerve III), which responds poorly or is completely unresponsive to light.
192 • THE VISUAL SYSTEM
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Integrated examination sequence for ophthalmology
• Introduce yourself and clean your hands.
• Explain what you will be doing.
• Observe the patient as they walk into the room, looking for:
• Facial asymmetry
• Proptosis
• Gait (may indicate a possible cerebrovascular accident).
• Check visual acuity in each eye for distance and near vision.
• Undertake an assessment of the visual fields:
• Look for homonymous hemianopia, bitemporal hemianopia or any other obvious visual field defect.
• Check the pupils:
• Assess direct and consensual reflex.
• Test for a relative afferent pupillary defect. Note that the pupils should be checked only after visual acuity and visual field assessments have been
undertaken, as the lights used to examine the pupils may dazzle the patient and interfere with accurate visual field and acuity assessment.
• Dilate both pupils using tropicamide 1% eye drops.
• Examine each eye using the direct ophthalmoscope:
• Assess the ocular surface.
• Look at the red reflex (opacity may indicate either a cataract or vitreous opacities such as debris or haemorrhage).
• Focus on the optic disc: look at colour, shape and cupping, as well as swelling.
• Examine the blood vessel arcades in each quadrant.
• Examine the macula.
• Ask patient to look up, down, right and left so you can examine the peripheral retina.
• Examine extraocular movements if the patient presents with diplopia or if it is clinically indicated.
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