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Amaurosis Fugax Essentials for the Ophthalmic Practitioner Amaurosis fugax Amaurosis – darkening, obscure Fugax – fugitive AF and stroke: Statistical evidence Strokes per year in US: 700,000 ≈ 30% are recurrent stroke 25% mortality TIA and AF: greatest risk of stroke is 1st week* TIA and AF: 10.5% risk of stroke in 90 days* * Rothwell,PM, et.al. Timing of TIAs preceding stroke: time window for prevention is very short. Neurology. 2005;64:817-820 AF vision loss Transient (1-10 min) Partial to total loss Often begins in upper field Painless Unilateral (except if vertebrobasilar insuff.) Commonly no precipitating factor Fully reversible (w/in minutes, hrs) AF – Outline for course discussion I. Thromboembolism II. Non-embolic, hemodynamic causes of AF III. Masqueraders of true AF IV. In-office examination V. Primary auxiliary testing VI. Optometric Management VII. Medical, surgical treatment considerations I. Thromboembolism - ICA Factors associated with higher risk of stroke ICA stenosis of 80-94% Age >75 Male gender History of hemispheric TIA or stroke History of intermittent claudication Absence of collateral circulation - Benavente,O.,et.al. Prognosis after transient monocular blindness associated with carotid artery stenosis N Engl J Med. 2001 Oct 11;345(15):1084-90 Thromboembolism carotid sinus Biopathology of hemodynamic shear stress Greatest plaquing: carotid sinus outer wall Flow stasis = low shear stress = intimal proliferation Shear stress = atheroprotective endothelial response Thromboembolism vertebral – basilar arteries Brain stem ischemia Homonymous vision symptoms Dipl, cortical blindness Vertigo, disequilibrium Dysphasia, dysarthria Medical management Endovascular surgery Thromboembolism cardiac 20% ischemic strokes Often calcific Atrial fibrillation Valve disease Prosthetic valves Cardiomyopathy Thromboembolic disease Patent foramen ovale Nearly half (43%) of young patients (<50yrs) with cryptogenic ischemic stroke in this study have a patent foramen ovale. MesaD, et.al. Prevalence of patent foramen ovale in young patients with cerebral ischemic accident of unknown origin Rev Esp Cardiol. 2003 Jul;56(7):662-8 Other conditions with clot risk Pregnancy; birth control pills Sickle cell Hypercoagulable conditions Mostly pediatric, young adult Inherited thrombophilias Protein C, Protein S deficiencies Factor V Leiden (blood clotting protein) Antithrombin III deficiency II. Hemodynamic cause Relative retinal, ON vascular insufficiency Generalized atherosclerosis → Rapid drop in CRA pressure Induced by Exercise Bright lt./brightness intolerance Postural changes / hypotensive episodes Low cardiac output ECA, ICA, ophthalmic artery high grade stenosis Takayasu’s disease Hyperviscosity conditions Gaze-induced AF secondary to orbital tumor ICA dissection 50% pts w/ dissection and stroke have no history of antecedent neck trauma - BassiP, et.al. Cervical cerebral artery dissection: A multicenter prospective study. Neurol Sci. 2003;24 (suppl 1): S4-S7 Carotid aneurysm Idiopathic cause No identifiable lesion or hemodynamic cause Vasospastic? Migraine? III. Ocular presentations w/ transient blur Transient obscurations Papilledema, intracranial pressure “graying out” of vision / seconds / rarely total loss Occult ION Malignant hypertension Prodrome of CRVO Optic neuritis Compression of ON, optic chiasm Other “sudden loss of vision” considerations Glaucoma / extreme IOP Vitreous hemorrhage Vitreous floaters Hyphema “Overnight” cataract or PCO Corneal decompensation, edema Numerous others IV. In-office examination Detailed CC, history BP; pulse; cervical and heart auscultation Neurologic eye testing SLE Ophthalmoloscopy o Retinal edema; hemorrhage o Disc edema; pallor o Arteriole attenuation; emboli Ocular ischemic syndrome Hypoperfusion syndrome; rubeosis ODM – measure CRA pressure o Digital ODM w/ contralateral comparison Exophthalmometry – r/o orbital disease Prospective study 145 pts. over 3 years referred for Doppler studies due to eye signs, symptoms Predictive value of identifying significant ICA stenosis - 20.0% positive with amaurosis fugax - 18.2% positive with Hollenhorst plaque(s) - 20.0% positive with hypoperfusion retinopathy - other eye findings demonstrated poor predictive value - McCullough, HK, et.al.; Ocular findings as predictors of carotid artery occlusive disease: is carotid imaging justified? J Vasc Surg. 2004 Aug;40(2):279-86 V. Primary auxiliary tests Laboratory Sed rate and CRP (abnl >30mm/hr; >0.9mg/dL) CBC w/ differential Platelets (ref. range 150,000-350,000/mm3) Lipid panel (lipoproteins, cholesterol, triglycerides) Glycosylated Hb and FBS Homocysteine if elevated: 2X RR of stroke Antinuclear antibody (Lupus) Anti-phospholipid antibody Study Antiphospholipid Ab testing in 368 patients over 3.5 years with ophthalmic occlusive disease -86 patients tested positive (23.4%) vs. 5% general pop. -CRVO = 18% APA positive; BRVO = 24% -CRAO = 22% APA positive; BRAO = 32% -AION = 23% - Palmowski-Wolfe, AM, et.al.;Antiphospholipid antibodies in ocular arterial and venous occlusive disease Ophthalmologica. 2007;221(1):41-6 Cerebrovascular studies Noninvasive Doppler ultrasound B-mode ultrasound Direct view Color Doppler Trickle flow, “string sign” Duplex Subclavian steal: vertebral, subclavian Retrospective study in the UK covering 3 years of consecutive eye clinic patients referred for carotid Doppler 55% were positive for ICA stenosis 20% had >70% stenosis - Mukherji,W.et.al. Indications and outcome of carotid Doppler ultrasound: an ophthalmic perspective. Eur J Ophthalomol. 2004 May-Jun;14(3):240-4 Transcranial Doppler Pulsed Intracranial blood directionality, velocity Ophthalmic artery: antegrade? Retrograde? Steal phenomenon? Magnetic resonance angiography Noninvasive Time-of-flight technology, excellent for blood flow evaluation Arteriography “Gold standard” Risks Cardiac studies Echocardiography identified a potential cardiac or proximal aortic source for embolism in 16 / 73 (21.9%) of patients; including 8 who also had atrial fibrillation and ICA stenosis >50%. 8/73 (11.0%) had lesions only detected by ECG. -Mouradian,M, et.al.;Echocardiographic findings of patients with retinal ischemia or embolism J Neuroimaging 2002 Jul;12(3):219-23 VI. Optometric management Identify and manage if ocular cause Glaucoma, BRVO, hyphema, vitreous hemorrhage, etc. Measure BP, pulse, auscultation Stat ESR and CRP (r/o occult GCA) Individualize suspicion and focus of examination Age Health and family history Communicate with family practitioner! o Phone call same day; written report Laboratory; hematology tests Temporal artery biopsy if CRP, ESR, and GCA suspected Duplex/Doppler ultrasound; cerebrovascular studies Echocardiogram; cardiac studies ASA /anti-platelet option Management concerns Misdiagnosis of symptoms and working dx Underestimate urgency of situation No follow-up w/ primary care physician or patient Diagnosis delay: referral to an inappropriate subspecialist How would YOU manage the AF patient? - Questionnaire sent to 1,600 GPs; 54% response 72% would refer pt. to specialist 36% would start anti-thrombotic treatment - Donders,RC, et.al.;How do general practitioners diagnose and manage patients with transient monocular loss of vision of sudden onset? J Neurol. 1999 Dec;246(12):1145-50 VII. Surgical treatment: high grade stenosis = of proximal ICA North American Symptomatic Carotid Endarterectomy Trial (NASCET) Carotidendarterectomy (CEA) advised if >70% stenosis and symptomatic: - Stroke risk: 9% in 2 years if surgery - Stroke risk: 26% in 2 years if medical management Symptomatic moderate ICA stenosis (50-69%) had a 5-year rate of ipsilateral stroke: - 15.7% surgically treated (CEA) - 22.2% medically treated Symptomatic ICA stenosis of <50% no benefit from CEA - Barnett,HG, et.al.(NASCET Collaborators); Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis; N Engl J Med. 1998 Nov 12;339(20):1415-25 ICA angioplasty and stenting Controversial Long term results pending More controlled studies Surgeon dependent Primary advantage is local anesthetic Catheter with balloon Metal-mesh stent Treatment – medical intervention Prevention of ischemic stroke Meta-analysis of randomized 21 trials Antiplatelet treatment o 28% RR reduction – nonfatal stroke o 16% RR reduction – fatal stroke - Antithrombotic Trialists Collaboration. Collaborative meta-analysis of randomized trials of antiplatelet therapy for prevention of death, MI, and stroke in high risk patients. BMJ 2002; 324:71-86 Case presentations