• Transient loss of vision in 1 or both eyes
– Transient monocular visual loss (TMVL)
– Transient binocular visual loss (TBVL)
– System(s) affected: Central nervous system, ocular
• Diabetes mellitus
• Cardiac disease
• Hypercoagulable states
• Polymyalgia rheumatica
• Medications and drugs
Hypercoagulability—Factor V Leiden (AD), antithrombin III deficiency (AD), protein S and C deficiency (AD), dysfibrogenemia (AD), hyperhomocystinemia (AD), and hemoglobin S (AR)
• Smoking cessation
• Control of hypertension
• Achieve and maintain glycemic control
• Treatment of dyslipidemia
• Anticoagulation of atrial fibrillation, high-risk cardioembolic disorders
– Ischemia of retina, optic nerve, choroid
– Ocular—surface disease, angle-closure glaucoma, and hyphema
– Transient ischemic attack–ischemia of occipital cortex
– Migraine–cortical spreading depression
– Seizure–neuronal hyperexcitability and hypersynchrony
– Atherosclerotic large-vessel disease–carotid or ophthalmic artery, aortic arch stenosis with decreased ocular perfusion or thromboembolism. Coincident hypotension may elicit symptoms
– Cardioembolic–arrhythmia, valvular disease, thrombus, tumor with embolization to eye, etc.
– Vasculitis–giant cell arteritis causing retinal artery occlusion or arteritic anterior ischemic optic neuropathy
– Hypercoagulable states– retinal arteriolar or venous thrombosis. Cardiac thrombi
– Carotid artery dissection–traumatic or spontaneous with occlusion or thromboembolism
– Retinal artery vasospasm– retinal migraine. Especially in young adults. Associated headache or periorbital pain
– Papilledema and optic disc drusen–edema causes decreased retinal perfusion
– Central retinal vein occlusion–decreased venous outflow
– Ocular disease
Angle-closure glaucoma, hyphema, surface disease
– Ischemia: Vertebrobasilar insufficiency (VBI) secondary to atherosclerotic disease, cardioembolic source, or vertebrobasilar dissection. Hypotension often elicits symptoms.
COMMONLY ASSOCIATED CONDITIONS
• Atrial fibrillation
• Trauma–head and neck. Carotid and vertebrobasilar dissection
• Polymyalgia rheumatica–giant cell arteritis
• TMVL versus TBVL- monocular or binocular visual loss. Patients with binocular hemianopic visual field loss will often incorrectly assign it to the eye with the temporal field loss and report monocular visual loss.
• Duration and frequency of visual loss–sudden or abrupt onset. Much overlap of duration
– Seconds: Transient visual obscurations of papilledema or optic disc drusen. Ocular surface disease which improves with blinking or eye rubbing
– Seconds to minutes: (30 sec to 30 min) Ischemic
– Minutes: (10–60 min) migraine
– Minutes–days: Seizures
– Frequency of events–isolated or recurrent
• Description of visual loss
– Positive visual phenomena
– Photopsias (e.g., flashes, sparkles)–ischemia more likely to have negative visual phenomena
– Scintillating fortification scotoma (migratory, bright, zigzag light)–migraine
– Flickering, bright-colored shapes, geometric forms—seizures
– Negative visual phenomena
Curtain, shade, altitudinal, or complete loss–ischemic TMVL
Blurry, foggy, hazy, patchy, dim–nonspecific, often ischemic TMVL
Dim, blurred, and complete–ischemic TBVL
• Precipitating factors
– Orthostasis–-hypotension produces symptoms in critical arterial stenosis.
– Light-induced–severe carotid stenosis or giant cell arteritis
– Head or neck trauma, chiropractic manipulation–carotid or vertebral dissection
• Associated symptoms
– Contralateral hemisensory or motor symptoms, lightheadedness, aphasia–carotid stenosis
– Neck pain, headache, ipsilateral Horner’s syndrome, contralateral sensory or motor symptoms–carotid dissection
– Headache, scalp tenderness, jaw claudication, myalgias, diplopia–giant cell arteritis
– Eye pain–retinal vasospasm in young adults with a prior history of migraine, angle-closure glaucoma
Vertigo, diplopia, dysarthria, facial numbness–VBI
Severe headache or posterior neck pain with VBI symptoms–vertebrobasilar dissection
Headache following visual loss, nausea, vomiting, photophobia–migraine
Headache, altered consciousness, nausea, vomiting, blinking, nystagmus—seizure
• Drugs and medications
– Prescription, over the counter, illicit, oral contraceptives, cocaine
• Family history
– Cerebrovascular and cardiac disease
– Clotting disorders
• Vital signs
• Carotid auscultation–bruit in carotid stenosis
• Palpate superficial temporal artery–decreased pulse, cords, and tenderness in giant cell arteritis
• Visual acuity–may be reduced if permanent retinal or optic nerve ischemia
• Pupils—may have afferent papillary defect with permanent retinal or optic nerve ischemia
• Extraocular motility—may have cranial nerve palsy in giant cell arteritis
• Slit-lamp examination
– Corneal dryness, keratitis
– Narrow angles—angle-closure glaucoma
– Neovascularization of iris or angle, flare in anterior chamber–ocular ischemic syndrome
• Tonometry–low intraocular pressure: ocular ischemic syndrome or high intraocular pressure: Angle-closure glaucoma
• Funduscopic exam
– Optic nerve-disc edema, drusen
Cotton wool spots, retinal edema or hemorrhage, arteriolar narrowing, boxcarring or sheathing, venous dilation
Cholesterol emboli–yellowish orange, refractile, rectangular, often at vessel bifurcation. Source: Carotid or great vessels
Platelet—fibrin emboli–dull, grayish white, long. Source: Carotid, heart valves, coagulopathy
Calcific-chalk white, large, and round. Source: Heart valves, great vessels
DIAGNOSTIC TESTS & INTERPRETATION
• Automated visual field defect present if permanent retinal or optic nerve ischemia
• Elevated erythrocyte sedimentation rate and C-reactive protein. CBC: thrombocytosis in giant cell arteritis
• EKG–atrial fibrillation or sick sinus syndrome
• CBC, SPEP, PT, PTT, factor V Leiden, protein S and C, antithrombin III, homocystine, fibrinogen, antiphospholipid antibodies may identify hypercoagulable state, especially in young patients without risk factors for vascular disease.
• Lipid profile–elevated in atherosclerotic disease
– Carotid duplex ultrasonography–identifies degree of carotid stenosis and plaque morphology. May identify carotid dissection
– Transthoracic echocardiography—detects mural thrombi, valvular and wall motion pathology, and tumors.
– MRI brain–identifies parenchymal ischemic disease. May identify carotid dissection
– CTA or MRA of brain and neck–mural thickening and luminal narrowing of carotid dissection. Can demonstrate carotid stenosis and plaque.
– MRI brain–may demonstrate ischemic areas in posterior circulation distribution. Reserve for atypical presentation of migraine. See Migraine chapter.
– CTA or MRA brain and neck: Stenosis or occlusion of vertebrobasilar system in patients with dissection
– Transthoracic echocardiography–See TMVL above.
Follow-up & special considerations
• Transesophageal echocardiography–reserve for patients with high degree of suspicion of valvular disease, septal defects, and aortic arch disease
• Carotid angiography—differentiates 99% stenosis from complete occlusion
• Holter monitor–may identify intermittent arrhythmia
• Intravenous fluorescein angiogram–retinal, optic nerve, or choroidal ischemia
• Temporal artery biopsy—giant cell arteritis
• EEG–epileptiform activity in seizures
Temporal artery biopsy: inflammatory mononuclear cell infiltrate with destruction of internal elastic lamina; giant cells may be present
• Giant cell arteritis–See Giant cell arteritis chapter.
• Carotid stenosis >70%—ASA 325 mg/day, clopidogrel 75 mg/day, or ASA 25 mg plus dipyridamole 200 mg b.i.d.
• Carotid or vertebral dissection—anticoagulation with i.v. heparin followed by warfarin
• Cardiac disease—treatment of arrhythmia, valvular disease, CHF. Anticoagulation (target INR 2.5)
• Seizures–anticonvulsant therapy
• Vasospasm in young patients–calcium channel blockers
Carotid or vertebral dissection–anti-platelet therapy if anticoagulation is contraindicated
Carotid stenosis 70–99% and good surgical candidate–carotid endarterectomy
• Giant cell arteritis with visual loss
• Carotid or vertebral dissection
• Unstable cardiac arrhythmia
Instruct patient to report any change in vision or neurologic status
• TMVL (non-cardioembolic): Long-term antiplatelet therapy (1)
• Atrial fibrillation, cardioembolic source, some hypercoagulable states: Long-term anticoagulation
• Giant cell arteritis: Oral prednisone taper over 1–2 years dictated by symptoms, sedimentation rate, and C-reactive protein.
• Discontinue cigarette smoking
• Blood pressure reduction
• Fasting blood glucose <126 mg/dL
• Treatment of hyperlipidemia
• Follow-up with neuro-ophthalmology in 1 week
• Follow-up with neurology and/or cardiology as dictated by underlying disease
Avoid excessive alcohol use.
• In most young patients (<45 years of age) with TMVL, no etiology will be found. Their risk of stroke is low (2)[C].
• In TMVL with 50–99% carotid stenosis who were treated medically the 3-year risk of ipsilateral stroke is 10% (3)[A].
• Cerebrovascular accident
• Myocardial infarction
1. Albers GW, Hart RG, Lutsep HL, et al. AHA Scientific statement: Supplement to the guidelines for the management of transient ischemic attacks: A statement from the Ad Hoc Committee On Guidelines for the Management of Transient Ischemic Attacks, Stroke Council, American Heart Association. Stroke 1999;30:2502–2511.
2. Tippin J, Corbett JJ, Kerber RE, et al. Amaurosis fugax and ocular infarction in adolescents and young adults. Ann Neurol 1989;26:69–77.
3. Benavente O, Eliasziw M, Streifler JY, et al., for the North American Symptomatic Carotid Endarterectomy Trial Collaborators. Prognosis after transient monocular blindness associated with carotid artery stenosis. N Engl J Med 2001;345:1084–1090.