A 75-year-old man comes to the office due to intermittent right eye vision loss. The patient reports 3 episodes over the past 2 months in which he suddenly experienced "a curtain falling over the right eye" for several minutes before it spontaneously resolved. He has no eye pain or discomfort, focal weakness, numbness, or headache. His medical history is significant for hypertension, hyperlipidemia, and osteoarthritis. He smoked cigarettes for 25 years before quitting at age 50. Blood pressure is 140/85 mm Hg and pulse is 74/min. Visual acuity, pupillary reflex, and funduscopic examinations are unremarkable. Further neurologic examination shows normal reflexes, motor strength, and sensation. Which of the following is most likely to yield the diagnosis in this patient?

Question

A 75-year-old man comes to the office due to intermittent right eye vision loss.  The patient reports 3 episodes over the past 2 months in which he suddenly experienced "a curtain falling over the right eye" for several minutes before it spontaneously resolved.  He has no eye pain or discomfort, focal weakness, numbness, or headache.  His medical history is significant for hypertension, hyperlipidemia, and osteoarthritis.  He smoked cigarettes for 25 years before quitting at age 50.  Blood pressure is 140/85 mm Hg and pulse is 74/min.  Visual acuity, pupillary reflex, and funduscopic examinations are unremarkable.  Further neurologic examination shows normal reflexes, motor strength, and sensation.  Which of the following is most likely to yield the diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d570_a9bc_bc81_515650308e94_MD0003_00 This patient has amaurosis fugax, which is characterized by painless, rapid, and transient (<10 minutes) monocular vision loss. The description of a curtain descending over the visual field is highly suggestive of this diagnosis. The most common etiology is retinal ischemia due to atherosclerotic emboli originating from the ipsilateral carotid artery; therefore, patients with vascular risk factors (eg, hypertension, hyperlipidemia, smoking) should be evaluated with a duplex ultrasound of the neck. Funduscopic examination is often normal but may show embolic plaques and retinal whitening (due to ischemia). Patients with amaurosis fugax and concomitant carotid artery disease have an increased risk of stroke. Other causes of transient monocular vision loss are uncommon and include cardioembolic disease, giant cell arteritis, retinal vein occlusion, retinal vasospasm, and papilledema. Retinal detachment also sometimes causes the sensation of a curtain descending over the eye, but symptoms are unlikely to resolve within minutes. (Choices A and F) Neuroimaging with CT scan or MRI may be considered in patients with suspected structural brain disease (eg, stroke, tumor, infection, demyelinating plaques). However, the absence of headache, seizure, mental status changes, or focal neurologic deficits makes this less likely in this patient. (Choice C) Echocardiography can be helpful in evaluating for cardioembolic disease (eg, atrial thrombus in the setting of atrial fibrillation), which typically leads to transient ischemic attack or stroke. Cardioembolic disease is a much less common cause of amaurosis fugax compared to carotid atherosclerosis. (Choice D) Erythrocyte sedimentation rate should be considered in patients age >50 with monocular vision loss to evaluate for temporal (giant cell) arteritis. However, this diagnosis is unlikely in this patient as other features are not evident, such as unilateral headache, jaw claudication, constitutional symptoms (eg, fever, fatigue), and polymyalgia rheumatica (eg, proximal muscle stiffness). (Choice E) Lumbar puncture and CSF analysis (eg, oligoclonal bands) may be considered in patients with suspected multiple sclerosis, which often presents with optic neuritis. However, optic neuritis usually presents in women age <50 with monocular vision loss and pain on eye movement. Patients also typically have an afferent pupillary defect with optic disc swelling on funduscopy. (Choice G) Ocular tonometry is indicated for measuring intraocular pressure in patients with acute angle-closure glaucoma, which typically presents with painful monocular vision loss, headache, and nausea/vomiting. Examination findings usually include conjunctival injection with a poorly reactive mid-dilated pupil. Educational objective: Amaurosis fugax is characterized by painless, rapid, and transient monocular vision loss. The description of a curtain descending over the visual field is highly suggestive of this diagnosis. The most common etiology is retinal ischemia due to atherosclerotic emboli originating from the ipsilateral carotid artery; therefore, patients with vascular risk factors should receive a duplex ultrasound of the neck. References: A 65-year-old man with transient monocular vision loss. (http://www.ncbi.nlm.nih.gov/pubmed/24847142) Transient monocular blindness. (http://www.ncbi.nlm.nih.gov/pubmed/16833032)

A 75-Year-Old Man Comes to the Office Due to Intermittent