Contents
328 Introduction
328 History
331 Examination
363 Neuro-imaging
Introduction
The majority of neuro-ophthalmic disorders are not “spot diagnoses”, i.e. they are not apparent with a brief slit-lamp or fundoscopic examination. However, many can be diagnosed clinically or with a minimum of investigations, provided that a full history has been taken and an accurate examination performed.
The aims of the history and examination are to:
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clearly define the presenting complaint
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quantify the degree of impairment
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localize the site of the disease process
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establish the diagnosis or differential diagnosis
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identify possible precipitating factors or risk factors
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guide further investigations
History
The structure of the history is similar to that for any medical condition.
Patient Details
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age
Presenting complaint
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this must be asked in terms the patient can understand (e.g. it may be appropriate to ask a patient with transient visual loss if he/she has ever had migraines but also ask if he/she has ever had a “sick headache”)
A detailed description of the problem, including:
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nature of the problem (e.g. double vision, visual loss, blurred vision, headache)—why are you here today?
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timecourse
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time of onset: it is important to distinguish between time of onset and when the problem was first noticed (e.g. a patient who only incidentally notices visual loss in one eye when covering the other eye cannot clearly define time of onset)
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speed of onset and development over time
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variability throughout the day or from day to day
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“warning signs” prior to the onset of permanent loss of function (e.g. transient visual loss preceding permanent visual loss)
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status: is it still present or was it transient?
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associated symptoms/signs (e.g. numbness, weakness, headache)
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previous episodes
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frequency
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duration
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triggering/predisposing factors
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investigations/treatment so far
Other ophthalmic symptoms
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pain (site, timecourse, worse on moving eyes?)
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visual loss
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double vision
Ophthalmic history
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glasses or contact lenses
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eye drops, surgery or laser
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eye patching or strabismus surgery as a child (“did you ever have a lazy eye?”)
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details of last eye test: this may help to date the onset of visual loss
Medical history
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cancer
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autoimmune disease
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diabetes, hypertension, high cholesterol
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trauma, particularly to the head or neck
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surgery
Medications
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often give clues to systemic diseases forgotten by the patient
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many medicines may cause or exacerbate neuro-ophthalmic disorders including:
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optic neuropathy: ethambutol, isoniazid, amiodarone, drugs for erectile dysfunction
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raised intracranial pressure (ICP): corticosteroids, oral contraceptive pill, tetracyclines, vitamin A derivatives used for acne
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retinopathy: vigabatrin, tamoxifen, hydroxychloroquine
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double vision: penicillamine, aminoglycosides, others (drug-induced myasthenia)
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nystagmus: phenytoin, lithium
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Family history
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particularly of ophthalmic or neurologic disease
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if a positive history, it is useful to draw out a family tree
Social and occupational history
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marital status
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occupation
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visual requirements (e.g. driving)
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current or previous smoking or alcohol use
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current or previous use of illicit drugs
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diet/nutrition (if poor nutrition suspected, ask specifically what the patient ate yesterday, day before, etc.)
Symptoms of giant cell arteritis (GCA)
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all patients over 50 with a history of transient or permanent visual loss or double vision should be asked about:
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new or unusually severe headaches
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scalp and/or temple tenderness
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ache or pain in the jaw muscles on chewing food
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ear pain or ache
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tongue ache on talking or chewing
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fevers, fatigue, decreased appetite, weight loss, chronic cough
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muscle aches and pains
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Systems review questions
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symptoms (past or present) revealed by systems review questioning may either suggest an underlying systemic disease or help localize the site of a neuro-ophthalmic problem. Detailed questioning may not be necessary in all cases but for many, it provides important clues to the etiology of the disorder
General
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recent infections (infectious or postinfectious diseases)
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fevers, night sweats, fatigue, weight loss, poor appetite (cancer, chronic infection, GCA)
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recent head or neck trauma, chiropractic neck manipulation (traumatic visual loss or nerve palsy; internal carotid artery or vertebrobasilar dissection)
Neurologic
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headache (GCA, tumor, aneurysm, raised ICP)
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persistent hemifacial or hemicranial pain, numbness or “pins and needles” (tumor, aneurysm)
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“fits, faints, funny turns” (tumor, stroke, transient ischemic attacks)
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numbness or weakness (tumor, stroke, multiple sclerosis [MS])
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difficulties with speech, balance, micturition, bowel control (MS)
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fatigable weakness (myasthenia)
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transient episodes of numbness, weakness or vertigo in the past (MS, transient ischemic attacks)
Ear, nose, throat
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deafness (vestibular schwannoma)
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tinnitus (vestibular schwannoma; if pulsatile, suspect carotid-cavernous fistula [CCF] or raised ICP)
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sinus congestion or nosebleeds (nasopharyngeal carcinoma, Wegener granulomatosis)
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problems swallowing (myasthenia, oculopharyngeal dystrophy)
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mouth ulcers (Behçet)
Respiratory
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cough, short of breath, wheeze, “adult-onset asthma” (sarcoidosis, tuberculosis, cancer)
Cardiovascular
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history of “heart murmur” (embolic risk)
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chest pain (vasculitis, thrombosis)
Gastrointestinal
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abdominal pains, change in bowel habits, passing blood (cancer, inflammatory bowel disease, possible nutritional deficiency due to malabsorption, periarteritis nodosa)
Genitourinary
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burning or stinging on passing urine, genital ulcers or discharge, past history of a sexually transmitted disease (syphilis, HIV, Behçet)
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blood in urine (vasculitis, cancer)
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prostate symptoms (cancer)
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galactorrhea/amenorrhea (pituitary tumor)
Musculoskeletal
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muscle aches? (GCA, vasculitis)
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joint pain or swelling? (chronic infections, autoimmune diseases e.g. systemic lupus erythematosus [SLE])
Skin
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skin rash (syphilis, sarcoid, Lyme, vasculitis)
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new-onset easy bruising (leukemia)
Infectious risk factors
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friends or family with infectious disease (e.g. tuberculosis)
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recent travel to any regions where unusual infections possible?
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pets (cat scratch disease)
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tick bites (Lyme disease)
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intravenous drug use or blood transfusion (infectious diseases including HIV)
Examination
For most neuro-ophthalmological conditions, the history indicates the likely diagnosis or at least points the examiner in the right direction, and the examination is merely confirmatory. At the very least, the history indicates if a patient has a visual sensory disturbance (afferent pathway), double vision or abnormal eye movements (efferent pathway), a difference in the size of the pupils, drooping of the eyelid or headaches/facial pain. Therefore, it is often appropriate for the examination to focus on one of these areas. By doing so, however, there is a danger that other potentially diagnostic or localizing signs may be missed; for example, failing to notice decreased corneal sensation, anisocoria or even optic disc swelling in a patient with a sixth cranial nerve palsy. Similarly, it is frequently assumed that patients with transient symptoms will have a normal examination but a careful search may, for example, reveal peripheral retinal emboli in a patient with monocular transient visual loss (i.e. amaurosis fugax).
To avoid missing important signs, we recommend that a minimum neuro-ophthalmic examination (see summary box) be performed on all patients, supplemented where appropriate by a more detailed examination of the area suggested by the history. Instead of expecting that a particular part of the examination will yield normal findings, always assume that the examination results are going to be abnormal until you have proved that they are normal.
Patients with symptoms of previously undiagnosed systemic disease or a generalized neurologic disorder also require a full systemic and neurologic examination. You may wish to consider enlisting the assistance of a neurologist or internist.
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visual acuity (VA) at distance and near (best-corrected or with pinhole)
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color vision (Hardy-Rand-Rittler or Ishihara plates best)
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confrontation visual fields (finger counting, finger wiggling, red test object)
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perimetry, i.e. formal visual field testing before dilating drops if there are symptoms or signs of afferent pathway disease
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eye movements
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fixation holding (is there nystagmus?)
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primary position deviation (observation, cover test)
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ductions/versions (if limited in both eyes, test doll’s-head maneuver)
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pursuit
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saccades
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convergence (to an accommodative target)
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pupils
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size
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response to light (if poor, also test near response)
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swinging light test (for relative afferent pupillary defect [RAPD])
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lid position: ptosis, retraction
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orbits: proptosis (pulsatile?), enophthalmos, injection, chemosis, bruit
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corneal and facial sensation to light touch
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orbicularis oculi and facial muscle strength
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if patient over 50 and history consistent: palpate the temporal arteries for pulsatility and tenderness
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slit-lamp examination (before and after dilation)
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intraocular pressure (IOP)
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ophthalmoscopy after dilation, including careful optic disc, macular and peripheral retinal examination
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vital signs including blood pressure (in appropriate setting)
Visual acuity (VA)
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distance VA with the optimal refractive correction (or at least a pinhole) is an obvious first examination step
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however, remember that normal VA does not exclude serious visual pathway disease (patients can have dense bitemporal or hemianopic visual field defects with absolutely normal VA)
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test reading VA at 30 cm with the appropriate refractive correction as well (if the patient has to bring the reading card closer to see the print, indicate at what distance the chart was held)
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using a reading card with text rather than a card that just has individual letters or numbers provides an indication not only of the patient’s near acuity but also a sense of the patient’s cognition!
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if patient has poor near vision, can use a plus lens or a pinhole (as with distance vision) to see if it improves
Color vision ( )
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color vision is often decreased earlier, or more severely, than VA in optic neuropathies of many causes
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therefore, decreased color acuity is an important neuro-ophthalmic “warning sign” even if VA is normal
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however, congenital “color blindness” is common
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patients with congenital dyschromatopsia can be recognized because their color loss is bilateral, symmetric and asymptomatic; they have normal VA (or decreased VA explained by visible intraocular disease) and normal visual fields
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by contrast, patients with acquired dyschromatopsia usually have a visual field defect and/or decreased VA, often have asymmetric color loss and sometimes the color loss is symptomatic (colors look “washed out” or faded)
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the following are simple tests of color acuity
Subjective color desaturation ( Fig. 13.1 )
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in cases of a unilateral or asymmetric optic neuropathy, a colored target (such as the red top of an eyedrop bottle) will seem less colorful to the affected (or worse) eye than the unaffected eye (e.g. red appears brown or there is no color at all!)
Color plate tests (e.g. Ishihara or Hardy-Rand-Rittler pseudoisochromatic color plates)
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many color plate tests were designed to detect congenital color defects (which occur in approximately 8% of men and 1% of women)
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they have a number of limitations when applied to acquired visual pathway disease
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patients with reduced acuity may not be able to see the plates (the Ishihara plates are unreliable if the acuity of the eye being tested is 20/120 or worse)
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patients with a field defect may only see half of each plate (this may alert you to the presence of a field defect)
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patients with cognitive impairment may not be able to recognize a number formed out of dots (as seen in the Ishihara plates) even if they can identify the color of each dot on the plate individually
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nevertheless, color plate tests can provide a useful measure of color vision in acquired visual pathway disease
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it is important to choose one of the tests and to become familiar with its use and its limitations
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compare the number of plates seen with each eye
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if the patient is able to see all the plates with either eye, turn to a plate with no visible number and ask the patient to compare the saturation of color with each eye
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ask the patient to look at the plate with their better eye and to assess the brightness of the colors (like adjusting the color on a television)
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ask the patient to change to their other eye and compare the brightness of colors: “if you give the first eye 10 out of 10 for color brightness, would you give the second eye more, the same or less?”
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if patient cannot see any figures on color plates, can use objects or colors on a smartphone to check gross color perception
Visual fields to confrontation ( Fig. 13.2 and )
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confrontation testing is a useful qualitative test capable of detecting hemianopic, quadrantic, altitudinal and some central defects; however, a normal test does not rule out a more subtle defect
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confrontation testing cannot be used to monitor field loss
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it is important to develop a consistent technique
Descriptive
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the patient looks at your nose with one eye at a time
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ask “are all parts of my face equally clear or is a part blurred or missing?”
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this is a quick and surprisingly sensitive technique and can often detect subtle defects like central or paracentral scotomas which can be missed on standard confrontation testing
Finger counting in quadrants
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the patient covers their left eye, you close your right, they stare into your open eye
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holding both hands in the upper midperiphery area, hold out one or two fingers of each hand and ask “how many fingers in total?”
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then move both hands to the inferior midperiphery area and repeat
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repeat for the other eye
Red target for central field
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the patient covers their left eye, you close your right, they stare into your open eye
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you place a red target (hat pin or similar) in the middle of their field and ask “what color is this?”
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if the patient says red then you repeat the test with their other eye and ask them if the target is a brighter red in one or other eye
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if the patient reports that the color of the target is not red or less saturated in one eye, move the target away from the center of their affected eye and ask “is the red becoming brighter or duller?”
Red target for hemianopic defect
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particularly useful if a chiasmal defect is suspected
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ask the patient to compare the color saturation of a red target held in each quadrant
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if the patient reports desaturation in one quadrant, move the target towards the vertical and horizontal meridians and say “tell me when the red becomes brighter”
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Perimetry
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all patients with suspected visual pathway disease should have static or kinetic perimetry in order to:
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localize the site of the lesion in the visual pathway
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obtain a quantitative baseline against which future changes can be compared
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Fixation, alignment and eye movements ( )
A full ocular motility assessment may involve some or all of the following:
Fixation
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observation ( p. 337 )
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assessment of nystagmus ( p. 337 )
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assessment of inappropriate saccadic movements ( p. 338 )
Eye alignment in primary position
Eye movements
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range of movement (ductions and versions) ( p. 341 )
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pursuit ( p. 342 )
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saccades ( p. 342 )
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convergence ( p. 344 )
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vestibulo-ocular reflex (VOR) ( p. 345 )
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optokinetic nystagmus (OKN) ( p. 346 )
Special tests
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prism fusional amplitude ( p. 347 )
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head tilt test ( p. 348 )
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double Maddox rod test ( p. 349 )
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forced duction testing ( p. 350 )
Fixation
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acquired abnormalities of fixation (nystagmus or saccadic intrusions) frequently present with oscillopsia
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patients with congenital/early-onset fixation disorders do not usually complain of oscillopsia; they are more likely to be referred because they have been incidentally noticed to have abnormal eye movements
Observation
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the patient should be asked to look at a fixation target, initially in the primary position, then in eccentric gaze and finally on return to the primary position
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the eyes should be observed for continuous or intermittent oscillations; if the patient complains of oscillopsia but no oscillations are seen with the naked eye, he or she should be re-examined at the slit-lamp or with a direct ophthalmoscope
Assessment of nystagmus
(See also Chapters 7 and 8 .)
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waveform
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pendular (sinusoidal)
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jerk (slow movement away from fixation and a fast corrective movement in the opposite direction)
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mixed
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plane
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horizontal
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vertical
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torsional
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mixed
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direction
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the direction of the fast phase is used to describe jerk nystagmus (e.g. left-beating nystagmus has fast phase to the patient’s left)
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patients with horizontal jerk nystagmus should be observed for several minutes to see if the direction changes—the defining feature of periodic alternating nystagmus
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conjugacy
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conjugate: the fast and slow (if jerk) or slow (if pendular) phases of both eyes are in the same direction
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disconjugate: the fast and slow phases are in different directions (e.g. the right eye has slow phases to the right and fast phases to the left, whereas the left eye has slow phases to the left and fast phases to the right as in convergence-retraction nystagmus)
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influence of eye position
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is the nystagmus present in the primary position or only on eccentric gaze?
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does the plane vary with direction of gaze?
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does the intensity (amplitude times frequency) vary with direction of gaze or with convergence?
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is there a position where the intensity is least (null zone) or where the direction of jerk nystagmus reverses (neutral zone)?
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influence of fogging or occlusion
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is the intensity increased by fogging (use Frenzel goggles or a thin-rimmed +11D or greater spherical lens)?
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does the nystagmus only occur or change direction when one eye is occluded?
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influence of nystagmus on eye movements: does the nystagmus break up pursuit eye movements?
Assessment of inappropriate saccadic movements
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plane
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horizontal
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vertical
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oblique
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amplitude
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small (less than 5 degrees)
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large (more than 5 degrees)
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frequency
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high vs low
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duration
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intermittent (bursts)
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continuous (oscillations)
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Eye alignment in primary position
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abnormalities of ocular alignment usually present with persistent or intermittent double vision, unless the patient has poor vision or a childhood strabismus
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the cover test is the basic test of ocular alignment; it should be performed on all patients with neuro-ophthalmic symptoms
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the choice of further tests depends on the patient’s symptoms and the results of the cover test
Cover test ( Fig. 13.3 )
Purpose
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to detect manifest deviation (tropia) in the horizontal and vertical planes
