Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

Nomen:

Datum:

Refraction

Fig. 14.11: Normal Goldmann visual field (left eye).

Management This depends on the cause of the field loss. Consider eligibility to drive (p. 688) and test binocular Estermann field if in doubt.

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Optic disc swelling

Optic Disc Swelling

Background Papilloedema refers exclusively to optic disc swelling caused by raised intracranial pressure (ICP). There are many other causes of disc swelling.

History Take a full systemic, neurologic, and ophthalmic history. Headache from raised ICP may be stereotypic (p. 650).

Examination Check BP, cranial nerves (raised ICP may cause a 6th nerve palsy), VA, colour vision, pupils, refraction, dilated fundoscopy, and general examination as indicated by the history. Pulsating retinal veins exclude raised ICP (but only at the time the observation is made) but the converse is not true as absent spontaneous venous pulsations may be normal. Severe papilloedema causes blurring of the disc margin and nerve fibre layer thickening that obscures disc vessels. The normal optic disc cup is absent. Flame haemorrhages at the optic disc may occur, particularly in acute anterior ischaemic optic neuropathy (AION) and also acutely in raised intracranial pressure (Fig. 14.12). In central retinal vein occlusion (CRVO) there will be haemorrhages on the disc but also throughout the affected retina.

Differential diagnosis Consider: raised ICP; meningitis; posterior uveitis (panuveitis); infiltration or inflammation, e.g. leukaemia, sarcoid; demyelinating optic neuritis; posterior scleritis; compressive optic neuropathy, e.g. thyroid eye disease or sheath meningioma; malignant hypertension; diabetic papillopathy; Irvine-

Fig. 14.13: Optic disc drusen.

Gass syndrome; AION; CRVO; Leber’s hereditary optic neuropathy; carbon dioxide retention; hypoparathyroidism; uraemia.

Optic disc swelling may be simulated (pseudopapilloedema) by small hypermetropic discs, tilted discs, and disc drusen.

Optic disc drusen (Fig. 14.13) are calcified deposits in the optic nerve head which may be clearly visible but if buried may simulate disc swelling. They are sometimes associated with arcuate field loss. Drusen involute in later life. No treatment is available.

Investigations Arrange formal perimetry. If papilloedema is suspected, request neuroimaging and liaise urgently with neurology. If imaging shows no cause for raised ICP, lumbar puncture may be required to measure ICP. Photograph the optic discs. Consider fundus photos using angiography filters to show drusen autofluorescence (Fig. 14.14), or alternatively disc drusen are visible using ultrasound examination (calcium also shows

on CT).

Management Treat the underlying cause. If pseudopapilloedema is suspected, repeat disc photography, fields, VA, and colour vision after several months to check there has been no change, as this would suggest another diagnosis.

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Idiopathic Intracranial

Hypertension

Background A condition with raised intracranial pressure (ICP) but no mass lesion or hydrocephalus. Previously referred to as pseudotumour cerebri and benign intracranial hypertension. The syndrome known as idiopathic intracranial hypertension (IIH) occurs in women of childbearing age with a history of recent substantial weight gain. However, the same clinical picture may be associated with prolonged therapy with tetracyclines (most commonly minocycline for acne), anabolic steroids, danazol, exogenous growth hormone, hypervitaminosis A, isotretinoin, tretinoin, nalidixic acid, lithium, ciclosporin, pregnancy (probably related to weight gain), several endocrine disorders, chronic meningitis (especially in sarcoidosis), and vasculitis rarely. Dural sinus thrombosis is another cause of the pseudotumour syndrome, especially in association with prothrombotic disorders such as Behçet’s disease, pregnancy, antiphospholipid syndrome, protein S deficiency, protein C deficiency, oral contraceptive pill use, and Factor V Leiden mutation. In cases of dural sinus thrombosis the onset is more likely to be subacute. Also consider sleep apnoea syndrome, especially in obese males.

Symptoms Include headache (94%), unilateral or bilateral transient visual obscurations lasting seconds (68%), pulsatile tinnitus (58%), photopsia (54%), retrobulbar pain (44%), diplopia (38%), and loss of vision (26%). Headache may be throbbing, wake the patient from sleep, and be exacerbated by recumbent posture and Valsalva. It may improve on rising in the morning but get worse during the day.

Signs The patient is often very obese. There is bilateral papilloedema and there may be a unilateral or bilateral 6th nerve palsy. Visual fields may be severely constricted.

History and examination Take a full medical history and record medications, particularly those for acne. Check for neck stiffness, temperature, BP, VA, colour vision, confrontation visual fields, and IOP. Exclude vitritis and scleritis. Perform a full neurological examination and measure weight.

Differential diagnosis Consider any cause of papilloedema or disc swelling (p. 644). Exclude intracranial space occupying lesions (SOL), subarachnoid haemorrhage, meningitis, malignant hypertension, and dural sinus thrombosis.

Investigations Any patient presenting with headache and bilateral disc swelling needs urgent neuroimaging to exclude

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647

Idiopathic intracranial hypertension

imminent coning. In the pseudotumour syndrome MRI will not show hydrocephalus or a mass lesion, but there is usually evidence of chronic raised ICP (dilated optic nerve sheaths and so called ‘empty sella’). Dural sinus occlusion (by thrombosis or small SOL) is usually visible on brain MRI but MR venography may clarify. Once normal imaging has been obtained, arrange neuroophthalmological referral for lumbar puncture and perimetry. CSF constituents are normal and lumbar CSF pressure is raised

(>20 cmH2O, but usually >25 cmH2O). Request FBC, ESR, autoantibody screen, syphilis serology, U&E, calcium, phosphate, and glucose (should all be normal).

Treatment

■Lumbar puncture is a useful holding move.

■Weight loss: refer to a dietician and/or obesity specialist.

■Cease any drug thought to have precipitated the condition.

■Acetazolamide 250 mg b.d. p.o. if not contraindicated (warn about possible side effects). Higher doses may be required. The use of other diuretics is controversial but bendroflumethiazide (which has carbonic anhydrase activity) 2.5–5 mg o.d. is effective.

■If vision deteriorates or headaches persist despite medical management consider a CSF diversion procedure (lumboperitoneal or ventriculoperitoneal shunt). Optic nerve sheath fenestration is indicated for visual failure without headache.

■The use of corticosteroids is contraversial.

Follow–up Once the diagnosis is confirmed, see at 2–4 weeks with repeat field test, then less often if responding. The condition usually resolves spontaneously following cessation of the drug which initiated it, or after weight loss.

Headache and Facial Pain

Background Headache is one of the commonest of all symptoms. Patients seen in eye clinics usually have headaches localized to one or both eyes, associated visual symptoms, or concern that eye-strain is causing the headaches. Headache may be a manifestation of eye disease, or systemic disease may manifest with headache and altered vision.

History Ask about the mode of onset and duration of the headache, how often it occurs, the site, and relieving or exacerbating factors. The pain itself may have a throbbing quality, be constant or paroxysmal. Associated features may include: blurred vision; field defect; scintillating scotoma; nausea; photophobia; phonophobia; autonomic symptoms such as lacrimation, nasal congestion or Horner’s syndrome; scalp tenderness; jaw claudication; anisocoria, or tinnitus.

Examination Check BP (ensure the cuff pressure is high enough to occlude the radial pulse to ensure correct systolic measurement in patients with possible malignant hypertension), cranial nerves, VA, colour vision, pupils, confrontation fields, IOP, drainage angles, and fundoscopy (exclude disc swelling and retinal haemorrhage). Palpate the temporal arteries in those over 50 years. Consider refraction and orthoptic review.

Differential diagnosis

■Tension headache : a common, benign, headache that feels like a tight band across the forehead, around the head, or sometimes at the back of the head and involving the muscles in the back of the neck.

■Chronic daily headache : symptoms vary but pain is constant (24 hours a day) and not relieved by analgesics. Analgesic overuse is common. Insomnia usually coexists.

■Atypical facial pain : this condition has similar characteristics to chronic daily headache in that pain is unremitting but it is unilateral and usually localized to the cheek and periorbital region. Exclude local causes and treat as for chronic daily headache.

■Herpes zoster associated pain : Characteristic pain precedes

the appearance of a V1 rash. Postherpetic neuralgia occurs in 10% of cases. For managements, see page 182.

■Trigeminal neuralgia : must be lancinating (flashes of pain) most

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Headache and facial pain

Responds to carbamazepine or gabapentin. Refer to a neurologist.

■Other neuralgic facial pain : damage to the sensory nerves emerging from the orbit may result in neuralgic pain, particularly with a history of trauma or surgery, with sensory disturbance in the distribution of the affected nerve. Tapping the nerve produces pain: local anaesthetic relieves it. Refer to a pain specialist.

■Ocular causes : significantly raised IOP (almost always

>35 mmHg) produces ache around the eye. Uncorrected refractive error usually produces ache between the eyebrows. Scleritis causes a deep boring pain which may wake the patient from sleep.

■Giant cell arteritis : must be considered. See page 655.

■Raised intracranial pressure : produces headache with nausea and vomiting, often worse on waking, coughing, and bending over. A whooshing tinnitus is often present. Look for absent spontaneous venous pulsations. Check eye movements, pupil size, and reaction. Sixth nerve palsy may be a false localizing sign. Full neurological examination is essential. See page 647. Drowsiness and/or unilateral dilated pupil are serious signs suggesting coning and the need for urgent neurological intervention to prevent death. Contact a neurologist immediately if these signs are present.

■Low pressure headache : most commonly seen following lumbar puncture but chronic CSF leak may occur for a variety of reasons. The essential feature is that the headache is totally relieved by lying flat.

■Sinus infection : the patient typically has pyrexia, tenderness over the affected sinus (usually ethmoid), and pain worse on bending forward. Optic neuropathy can occur with severe infection or an expanding mucocele. Imaging (plain films are useful) shows opacification of the affected sinus; however, incidental sinus disease is common.

■Malignant hypertension : headache ± blurred vision. Look for retinopathy. Can cause confusion and fits.

■Subarachnoid haemorrhage : sudden onset of severe headache ‘like being hit over the head with a hammer’. Neck stiffness, decreased consciousness, or other neurological signs may be present. A diagnostic finding is subhyaloid haemorrhage. Lay

involvement may indicate an expanding posterior communicating artery aneurysm and imminent rupture. Anterior communicating artery aneurysm may affect the optic nerve in a similar fashion.

■Meningitis : features include photophobia, neck stiffness, possible decreased consciousness or neurological signs, and

pyrexia. Purpuric or petechial rash suggests meningococcal meningitis. Test passive neck flexion looking for stiffness ± pain (but may be normal in children). If passive straight leg raise causes pain, suspect meningism (or nerve root entrapment). Meningococcal meningitis can kill within hours; if

suspected, give intravenous benzylpenicillin immediately (300 mg in infants, 600 mg child 1–9 years, 1200 mg >10 years or adult).

■Migraine : see page 652.

■Cluster headache : paroxysmal attacks of severe pain, red watering eye, transient or permanent postganglionic Horner’s syndrome, and nasal stuffiness/rhinorrhoea. Patients pace around rather than lie still as with migraine. Usually lasts around 30 minutes, occasionally longer. Characteristically, a daily headache for several weeks, usually occurring at the same time of day, that then disappears for months or years. Usually affects middle-aged men, and may be precipitated by alcohol. Refer to a neurologist.

■SUNCT syndrome : Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing. Severe orbital, periorbital, forehead, or temple pain lasts from 5 seconds to a few minutes. Occurs from once daily to more than 60 times per hour. As with cluster headache, the dysautonomic features are an essential element.

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Migraine

Migraine

Background Migraine affects 15% of people, women more than men, with peak prevalence age 35–45 years.

Symptoms Visual aura may be hemianopic or affect the entire visual field. A slowly enlarging scotoma with a shimmering border evolves over a period of minutes, but usually resolves completely within 30 minutes. Zig-zag lines (fortification spectra/teichopsia) are pathognomonic. Vision recovers fully within 1 hour. Headache may occur about 30 minutes after the visual aura has resolved. Headache is typically unilateral, throbbing, and associated with nausea, photophobia, and phonophobia. It is usually exacerbated by movement and therefore relieved by lying down in a dark, quiet room. Nonvisual aura (vertigo, paraesthesia), migraine without aura (common migraine) and aura without headache (acephalgic migraine) can all occur.

History Ask patients about the nature of the attack, or past history of typical migraine headache in their early twenties. This may not be present in elderly patients presenting with aura without headache. If the visual aura is always restricted to the same hemifield this may very rarely be due to an occipital lobe lesion (such as an arteriovenous malformation, AVM).

Examination Ocular examination is normal. Field tests may be abnormal during an attack. Occasionally, persistent defects are seen, usually homonymous hemianopic scotomas. A 3rd, 4th or 6th nerve palsy (ophthalmoplegic migraine) occurs in children more frequently than adults, usually lasting for days or weeks. Perform dilated fundoscopy to exclude a retinal tear, embolus, or haemorrhage. Check BP, VA, colour vision, confrontation fields, and optic disc appearance. The occurrence of retinal migraine is controversial but nonembolic transient visual loss is sometimes referred to as retinal migraine. Similarly, ophthalmoplegic migraine is nosologically unclear.

Differential diagnosis Consider any cause of transient visual loss (p. 634) including amaurosis fugax, ocular ischaemia, narrow angle glaucoma, occipital epilepsy, retinal hole, tear or detachment, and occipital lobe AVM, or tumour (rare).

Investigations Not required unless atypical. Acephalgic migraine in older patients is not equivalent to a TIA.

Treatment Reassure the patient. Advise to pull over the car if they develop an attack whilst driving. Paracetamol or aspirin and an antiemetic relieve headache and nausea if taken early.