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Amaurosis fugax at downward gaze
SURVEY OF OPHTHALMOLOGY
CLINICAL
VOLUME 31 . NUMBER 6
l
MAY-JUNE 1967
CHALLENGES
RONALD M. BURDE, EDITOR
Amaurosis Fugax at Downward
Gaze
RIRI S. MANOR, M.D., AND ISAAC BEN SIRA, M.D. Comments by Jeffrey G. Odel, M.D., Steven A. Newman, M.D., and Lyn A. Sedwick, M.D.
The Neuro-ophthalmological
Unit, Department of Ophthalmology, Be&son
Hospital, Petah Tigva, Tel Aviv University, Israel
(In keeping with the purpose of a clinical pathological conference, the abstract and kc? words appear at the end of the article.)
right visual field demonstrated an enlarged blind spot and a lower inferior arcuate scotoma breaking out into a lower nasal step. There was a slight concentric contraction of the field in the left eye. The intraocular pressures were 16 mm Hg in each eye. Ophthalmoscopy revealed that the right disc was hyperemic and elevated with marginal splinter hemorrhages. The arterial and venous trees were normal in both eyes. A diagnostic procedure was performed.
Case Report. In June 1983, a 54-year-old man was sent to the Neuro-ophthalmological Unit for evaluation regarding the diagnosis: “Right amaurosis fugax due to carotid insufficiency most probable. Papilledema due to hypertensive disease.” His history included arteriosclerotic cardiovascular disease, two myocardial infarctions, hypertension, hypercholesterolemia and diabetes mellitus. The patient described his symptoms of the last few months as, “a transitory loss of the vision in the right eye when I look down suddenly.” An Amsler grid at reading distance in primary position or placed above the patient’s forehead was clearly seen; however, when the patient was asked to look from the primary position to an Amsler grid placed in the normal reading position, he claimed that the grid totally disappeared for a few seconds and then gradually reappeared from above downward “like a curtain” (Fig. 1). This phenomenon was reproducible. Examination revealed a visual acuity of 20/25 in the right eye and 20120 in the left. There was a relative afferent pupillary defect on the right, and brightness was interpreted as being 70% as bright in the right eye as in the left eye. The eyes were white and quiet, and there was no proptosis. The extraocular motility examination was normal. The
What is your dlyerential What diagnostic
diagnosis?
studies would you recommend?
Comments Comments By Jeffig G. Odel, M.D., Neuro-ophthalmology, Columbia-Presbyterian Medical Center, New York, New York For several months this 54-year-old man experienced obscurations of vision in the right eye upon assuming a downward gaze position. In each episode the visual image disappeared for a few seconds and then reappeared from above while the eye was in downward gaze. Examination of the right eye revealed mild depression of visual acuity, an arcuate scotoma, an enlarged blind spot, an afferent pupillary defect, and an elevated hyperemic disc with splinter hemorrhages. In view of his history of hy411
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Fig. 1. The visual obscuration noted on downward gaze is illustrated by means of the Amsler grid chart. 1. Initial total loss ofvision. 2 & 3. Recovery ofvision in stages from above downward.
pertension, diabetes, myocardial infarctions and hypercholesterolemia these episodes were presumed to represent transient ocular ischemic attacks, presumably hypotensive or embolic of carotid or cardiac origin.7,‘&‘%32 The differential diagnosis in this case must take into consideration transient monocular blindness in the presence of disc swelling and signs of optic nerve dysfunction. The differential diagnosis of amaurosis fugax depends on the duration and circumstances of symptoms, pattern of visual loss, and associated findings. 18,1gAttacks lasting seconds with an iris diaphragm pattern of visual field constriction, perhaps triggered by a postural change or carotid compression, suggest hypoperfusion. Attacks lasting 2 to 20 minutes with quadrantic, altitudinal, sequential or sudden total visual field loss, occasionally associated with fleeting photopsia, suggest emboli. Fundus examination may reveal these emboli or sheathing of the retinal vessels, suggesting their previous pasarteritis may present with transage. I5319Temporal sient monocular obscurations on standing or sitting which resolve on lying down.17 Patients with embolic or hypoperfusion amaurosis fugax (of carotid or cardiac origin) usually .do not have gaze-evoked attacks, swollen disc or signs of optic nerve dysfunction. Another frequent cause of transient visual loss, though unlikely in this case, is classic migraine.” It causes a binocular scintillating fortification scotoma typically starting paracentrally and expanding and migrating eccentrically, lasting up to 30 minutes.5~22 As the visual phenomenon passes headache may follow, though after many years of migraine it may not be as apparent and the visual phenomena may appear by themselves in the elderly.4~8~22Ocular migraine with retinal or choroidal ischemia is monocular and may be indistinguishable from embolic or hypotensive amaurosis fugax. In the patient under
MANOR,
BEN SIRA
35 years old transient monocular visual loss without other obvious cause is frequently attributed to ocular migraine. Infrequently it may result in fixed deficit, i.e., retinal artery occlusion or ischemic optic neuropathy where the disc appears swollen; however, amaurosis fugax in migraine is not gaze-induced. The most frequent cause of swollen discs and transient visual loss is papilledema, i.e., swollen discs on the basis of elevated intracranial pressure. It may be associated with transient visual obscurations lasting seconds3 and may be asymmetric and occasionally unilateral. The obscurations may be either monocular or binocular, may be posturally related,3,13s14 and have been ascribed to transient insufficiency of optic nerve perfusion.26 Since the perfusion pressure is the difference between capillary pressure and tissue pressure, transient changes in either can lead to visual obscuration. intracranial pressure which is High transmitted within the optic nerve sheath can lead to elevated intraneural tissue pressure in the optic nerve head by causing axoplasmic flow obstruction and venous congestion26~2g~30 so that transient drops in optic nerve head capillary pressure may readily result in obscurations. However, the obscurations of papilledema are not described as gaze-evoked, and this patient has no findings suggestive of elevated intracranial pressure. Transient obscurations similar to those seen in papilledema have been reported with other causes of acquired disc swelling, such as disc edema from optic nerve sheath meningioma and ocular inflammation. Elevated intraneural tissue pressure compromising optic nerve head perfusion is believed to be the basis here as well as in papilledema. Anomalies of the optic nerve head, e.g., optic nerve head drusen and tilted discs which may be mistaken for acquired disc swelling, may have obscurations on the same basis.26 This patient’s obscurations OCcurred in the presence of disc edema but were gazeevoked. Theoretically, if intraocular pressure were elevated on downward gaze from a muscle restriction36 it could further decrease perfusion pressure and lead to visual obscuration. Gaze-evoked visual loss has been reported with orbital mass lesions.‘,1’,3’~33-35This was first reported man with primary by Wright34,35 in a 37-year-old optic nerve sheath meningioma, good vision, no proptosis and a swollen disc. It has been reported subsequently with intraconal cavernous hemangioma,1,31 extraconal osteoma,33 and zygomatic fracture.” The patients reported with gaze-evoked blindness have all been under 40 years of age. Visual acuity between attacks is usually normal or mildly abnormal. The visual field reflects the state of the disc and
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optic nerve compromise, which is usually mild. The degree of proptosis varies from none to moderate. An afferent pupillary defect may or may not be present in primary gaze positions and may appear on assuming the appropriate gaze position. Gazeevoked blindness has been encountered on abduction, depression and adduction. Although the amaurosis is usually described as persisting if the eye remains in the eccentric gaze position, in this patient vision returned although eccentric gaze was maintained. The amaurosis has variously been attributed to constriction of the central retinal artery at its entry into the optic nerve by the tumor combined with elevated intraocular pressure, e.g., on assuming the appropriate gaze position,35 acute venous obstruction affecting the retina,’ or to a local circulatory disturbance in the intraconal optic nerve.“’ The rapid onset, clearing and brief duration of this patient’s obscuration, triggered by the mechanical stimulus of ocular rotation, is compatible with a vascular etiology. The occurrence on downward gaze and the presence of elevated disc suggest an intraorbital lesion. He most likely harbors an intraorbital mass, probably intraconal, which on downward gaze is compromising either optic nerve or retinal circulation. Given previous reports, the causative lesions probably would be optic nerve meningioma or hemangioma. At this point, a high resolution axial or coronal CT scan of the orbits with contrast is indicated to look for an orbital tumor. Fluorescein angiography might help to delineate the mechanism underlying the visual loss. Comments By Steven A. Newman, M.D., Departments of ~phtha~rno~o~ and Neurotogicat Surgery, University of Virginia, Charlottesville, Virginia This case of a 54-year-old man raises the interesting discussion of gaze-evoked transient visual disturbances. Clinically, we often distinguish visual loss by its duration. Episodes of amaurosis fugax usually have a sudden onset and last between one and ten minutes. When the epidose duration is less than a minute, these are often referred to as transient visual obscurations. This rough clinical distinction has proven useful in suggesting the pathophysiology and possible etiology. The rapidity of onset and brisk return of normal function has always suggested a primary vascular etiology. While thrombosis can cause acute loss of vision, repeated episodes argue for other pathophysiology. Emboli to the retinal vessels may produce transient, although more likely permanent, uniocular field defects. These may be cholesterol (Hollenhorst plaque), usually arising from an atherosclerot-
413
ic lesion in the neck, or less commonly, calcific, usually from a cardiac source. The classical diffuse loss of vision, however, occurs far from frequently related to showers of platelet emboli, usually arising from carotid atheromas, as described by C. Miller Fisher.’ Nonembolic vascular disease may also lead to transient visual disturbances2 Inflammation may be due to giant cell arteritis in older people and collagen vascular disease in younger. Although more frequently involving the posterior circulation, migrainous spasm may involve the retinal vessels as well, usually leading to stereotypical visual loss lasting 10 to 30 minutes. These may or may not be associated with other neurologic symptoms, including headache. Other rare vascular etiologies include hyperviscosity syndromes (macroglobulinemia) and emboli related to tumors.‘R Transient visual obscurations have classically been described in patients with papilledema. While some of the earliest authors suggested intermittent cerebral herniation with compromise of large posterior vessels,h more recent speculation centers on microvascular abnormalities at the level of the optic disc itself.‘5*23 It is believed that the swelling of the optic nerve fibers themselves3” further increases tissue pressure and compromise perfusion. While autoregulation usually maintains a careful balance intraocular, and tissue presbetween perfusion, sures,‘0~27 this may be altered in the setting of disc edema. Anything that then transiently decreases perfusion (drop in arterial blood pressure) or increases pressure at the disc (increased intraocular pressure?O) may result in temporary optic nerve dysfunction. This increased susceptibility to transient disturbances and vascular equilibrium would explain the frequent occurrence of transient visual obscurations with change in position (suddenly arising or stooping). Small drops in systemic arterial pressure or increase in intracranial pressure with subsequent increase in venous outflow pressure might well play a role. Transient visual obscurations have been reported frequently in patients with intracranial mass lesions.6 Most of these cases, we now feel, were related to disc edema. Transient visual obscurations in a select population with papilledema have been reported to occur in 60% or more and with episodes occurring up to 50 times per day.‘” Intracranial mass lesions may also produce visual loss by direct or indirect compression of the optic nerve. Two of Cogan’s 25 patients with blackouts not due to carotid occlusive disease were related to intracranial tumors.3 More recently, Hilton-Jones and associatesI reported two frontal lobe tumors (one astrocytoma and one meningioma) presenting with transient vis-
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ual loss unassociated with disc swelling. FrisCn and coworkers9 described a cystic craniopharyngioma which repeatedly caused visual loss related to reaccumulation of fluid. All of these episodes, however, lasted for longer periods of time. In the case of the frontal lobe tumors, it is thought that direct pressure may be applied to the optic nerve, either by the tumor itself or by herniation of the gyrus rectus beneath the falx. In 1979 Unsold and Hoyt3’ described a 29-yearold patient with monocular obscurations of vision evoked by right lateral gaze. A CT scan revealed an intraconal hemangioma. A second patient with gaze-evoked blackouts was reported by Brown and Shields in 1981.’ The patient described “haziness” progressing to “complete blackout” with progressive downward gaze, again related to a hemangioma. More recently, Dr. Ivor Levy and Dr. James Orcutt and associates each presented six cases of gaze-evoked amaurosis fugax at the Sixth Meeting of the International Neuro-Ophthalmology Society in Hakone, Japan (June, 1986). In all of the patients studied an intraorbital tumor could be demonstrated. Six of the 12 patients had meningiomas. There were three hemangiomas, one myoblastoma, one optic nerve glioma, and one undetermined mass. All three of Orcutt’s patients with meningiomas had optociliary shunt vessels. There did not appear to be a substantial increase in intraocular pressure associated with gaze-evoked visual dropout. This would suggest that microvascular hypoperfusion occurs either due to direct compression of the small vessels to the nerve itself, or possibly related to increased venous outflow obstruction and thus imbalance in perfusion pressure at the disc. Interestingly, gaze-evoked amaurosis fugax may occur with disc edema unassociated with an orbital tumor or increased intracranial pressure. Sadun and colleaguesz6 reported a patient with transient visual obscurations when looking to the left. In this patient, the disc swelling was believed to be related to inflammation with no evidence of mass lesion on CT scan. In the case presented here, the asymmetric disc swelling would make increased intracranial pressure or toxic etiologies far less likely. Of the three leading causes of unilateral disc swelling (mass leischemia, and inflammasion with compression, tion), the relative preservation of central visual acuity would be less likely in optic neuritis. While an intraorbital mass lesion would be most commonly expected to produce proptosis, this is not always the case. In particular, optic nerve sheath meningiomas and other slowly growing tumors around the optic nerve may often occur without proptosis. These, also, may produce transient visual 10~s.~Unsold and
MANOR,
BEN SIRA
Hoyt’s patient3’ was said to have “minimal proptosis,” and of 66 patients with orbital hemangiomas, Harris and Jakobiec I2 described no proptosis in 28%. Thus, first on my list of differential diagnoses would be that of an intraconal orbital mass lesion, most likely a hemangioma or possibly meningioma. I could not completely exclude the possibility of anterior ischemic optic neuropathy. Disc edema, even in the absence of a mass lesion, could predispose to transient, even gaze-evoked, obscurations. Certainly our workup would include an orbital CT scan. I would expect noninvasive studies of carotid flow to be normal.
Comments By Lyn A. Sedzerick, M.D., Neuro-ophthalmology, Florida Hospital, Orlando, Florida. Amaurosis fugax may result from a number of intraocular, intraorbital, intracranial, hematologic, vasospastic or thromboembolic conditions. This patient’s likely diagnosis amply demonstrates the importance of a complete ophthalmologic evaluation of all such patients. Transient loss of vision in one eye is usually a sign of transient loss of blood supply to the optic nerve and thus may be secondary to vascular occlusion, emboli-mediated or not, or hypoperfusion of the optic nerve. Vascular occlusion may occur from emboli, cardiac or carotid, or from spasm or compression of nonoccluded vessels. Patients with embolic disease usually complain of altitudinal or total loss of vision or blur of vision lasting less than 15 minutes with complete resolution. Sometimes plateletfibrin, cholesterol or calcific emboli may be seen in the fundus following such an attack. These emboli are presumably bits of a larger embolus which initially clogged vessels of the optic nerve and caused the visual loss before breaking up and moving downstream into the eye. Patients with vasospastic vascular occlusion, usually retinal migraine, may be seen to have attenuated retinal arterioles during an attack which may give symptoms identical to those produced by embolic vascular occlusion. Direct compression of nonoccluded vessels in the optic nerve, e.g., from papilledema or from any mass lesion that adjoins the optic nerve, results in visual loss which is usually very brief (several seconds) and is labeled as a transient obscuration of vision. Hypotension may result in monocular or binocular transient visual loss as may hyperviscosity syndromes, both from inadequate perfusion of the optic nerve. All of these entities are very nicely discussed by Burde, Savino, and Trobe.* Occasionally transient visual loss is secondary to an anomaly of the optic nerve itself, the most common being optic nerve drusen. These spells are
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characteristically very brief. Other ocular abnormalities, such as narrow filtering angles, may rarely produce painless visual changes which resemble amaurosis fugax from carotid or cardiac diseaseez5 The mechanism of such visual loss is probably raised intraocular pressure which results in poor perfusion of the optic nerve. The patient described here underscores the importance of ophthalmic evaluation of all patients who complain of transient visual loss. His symptoms of altitudinal visual loss of brief duration only in downward gaze suggest a compressive lesion in the orbit. Examination shows signs of optic nerve dysfunction (afferent pupillary defect, visual field loss) and reveals a unilateral hyperemic disc. The most likely diagnostic possibility is an optic nerve tumor or, less likely, a compressive orbital lesion which abuts the optic nerve. Although thyroid ophthalmopathy may cause transient loss of vision in certain positions of gaze from enlarged muscles which produce a compressive optic neuropathy, other characteristic signs of the disease are universally present such as lid lag, stare, adnexal swelling, conjunctival injection over rectus muscles, proptosis and restrictive myopathy, none ofwhich this patient demonstrates. Papilledema may be unilateral and may produce brief loss of vision in one eye; however, papilledema does not produce visual field changes, except an enlarged blind spot, until long-standing and has no propensity to cause loss of vision only in certain positions of gaze. Although optic nerve glioma and optic nerve sheath meningioma usually produce either proptosis or significant visual loss, they may present with modest visual impairment, or discernible proptosis and often cause “position dependent” transient visual loss. The mechanism of such amaurosis appears to be direct compression of the nerve or its vasculature.‘+ The diagnostic procedure in this case was probably a high resolution CT scan of the orbits which can distinguish glioma from meningioma about 75% of the time.*’ In the future, magnetic resonance imaging of the orbits with the help of surface coils for better definition may be the procedure of choice for these and other orbital lesions.
Case History Footnote of the orbit disclosed the presA CT examination ence of an enhancing tumoral formation situated intraconally, lateral and somewhat superior to the right optic nerve (Fig. 2). Orbital exploration was scheduled, but the patient had a third myocardial infarction and surgery was postponed. By December, 1983, the disc edema had regressed, and optic atrophy was evident. The patient continued to complain about amaurosis fu-
Fig. 2. Orbital CT scan showing the presence of a small space-occupying lesion adjacent to the right globe.
gax on downward gaze. Over the ensuing 18 months visual acuity in the right eye gradually decreased to 20150, the visual field contracted, but the amaurosis fugax on downward gaze disappeared. Tumor size remained relatively constant on repeat CT evaluations. The neuroradiologic diagnosis was that of cavernous hemangioma. At this point in time, the patient showed no interest in surgical intervention.
References 1. Brown 2. 3. 4.
5.
6.
7. 8.
GC, Shields GA: Amaurosis fugax secondary to presumed cavernous hemangioma of the orbit. Ann Ophthalmol f3tl205-1209, 1981 Burde RM, Savino PJ, Trobe JD: Clinical Decision in NeuroOphthalmology. St Louis, CV Mosby Company, 1985, pp 91-l 15 Cogan DG: Blackouts not obviously due to carotid occlusion. Arch Ophthalmol 66:180-187, 1961 Cohen GR, Harbison JW, Blair CJ, Ochs AL: Clinical significance of transient visual phenomena in the elderly. Ophthalmologv 91:436-442, 1984 Corbett JJ: complications of migraine and _- Neuro-ophthalmic cluster headaches, in, Smith CH, Beck RW (eds): Symposium on Neuro-Obhthalmoloev. Neurolopic Clinics 1:4. Philadelphia, WB Saundeis Co, 196, pp 973r995 Ethelberg S, Jensen VA: Obscurations and further time-related paroxysmal disorders in intracranial tumors. Arch New01 Psych& 68;130-149, 1952 Fisher CM: Observations of the fundus oculi in transient monocular blindness. Neurologv 9:333-347. 1959 Fisher CM: Late-life miuaine accomoaniments as a cause of unexplained transient iscYhemic attacks‘. CanJNeurol Sci 7:%17.
1980 9. Fristn L, Sjiistrand J, Norrsell K, Lindgren S: Cyclic compression of the intracranial optic nerve: uatterns ofvisual failure and recovery. JNeurol Neuro& Psych&v 39:1109-l 113, 1976 10. Geiier C, Bill A: Effects of raised intraocular pressure on retinal, preiaminar, laminar, and retrolaminer optic nerve blood flow in monkeys. InvestOphthalmol Vir .Sci 28:1030-1042. 1979 11. Hampton GR, Krohel GB: Gaze-evoked blindness. Ann Ophtholmol 15:7>76, 1983 FA: Cavernous hemangioma of the orbit: A 12. Harris GJ, Jakobiec clinicopathologic analysis of 66 cases. in. Jakobiec FA (ed): Ocular hnd Ad&z1 Tumws. Birmingham. A&ulapius, 1978, pp 741-781 13. Hayreh SS: Optic disc edema in raised intracranial pressure. V.
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Pathogenesis. Arch Ophthalmol 95:1553-1565, 1977 14. Hayreh SS: Optic disc edema in raised intracranial pressure. VI. Associated visual disturbances and their pathogenesis. Arch Ophthalmol95:1566-1579, 1977 15. Hayreh SS: Structure and blood supply of the optic nerve, in, Heilmann K, Richardson KT (eds): Glaucoma. Conceptions of a Disease. Pathogenesis, Diagnosis, Therapy. Stuttgart, Georg Thieme, 1978, pp 78-96 16. Hilton-Jones D, Ponsford JR, Graham N: Transient visual obscurations, without papilloedema. J Neural Neurosurg Psychiatry 45:832-834, 1982 17. Hollenhorst RW: Effect of posture on retinal ischemia from temporal arteritis. Arch Ophthalmol 78:56!%577, 1967 18. Hoyt WF: Ocular symptoms and signs, in, Wylie ES, Ehrenfeld WK (eds): Extracranial Occlusive Cerebrovascular Disease: Diagnosis and Management. Philadelphia, WB Saunders, 1970, pp 64-95 19. Hoyt WF: Retinal ischemic symptoms in cardiovascular diagnosis. Postgrad Med October, 1972, pp 85-90 20. Jaeger EA, Severs RJ, Weeks SD, Duane TD: Visual field changes during positive acceleration. Aerospace Med 35:96%972, 1964 21, Jakobiec FA, Depot MJ, Kennerdell JS, et al: Combined clinical and computed tomographic diagnosis of orbital glioma and meningioma. Ophthalmology 91: 137-155, 1984 22. Lashley KS: Patterns of cerebral integration indicated by the scotomas of migraine. Arch Neural Psychiat 46~331-339, 1941 23. Lieberman MF, Maumenee AE, Green WR: Histologic studies of the vasculature of the anterior optic nerve. Am J Ophthalmol 82:405-423, 1976 24. Miller NR: Compressive optic neuropathies with optic disc swelling, in Miller NR (ed): Walsh and Hoyt’s Clinical Neuroophthalmolou. Baltimore, William & Wilkins, 1982, 4th edition, volume 1, chapter 15, pp 24%253 25. Ravits J, Seybold ME: Transient monocular visual loss from narrow-angle glaucoma. Arch Neural 41:991-993, 1984 26. Sadun AA, Currie JN, Lessell S: Transient visual obscurations
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optic discs. Ann Neural 16:48%494, 1984 DR: Effect of elevated intraocular pressure on bloodflow. Occurrence in cat optic nerve head studied with iodoantipyrine I ‘25 Arch Ophthalmol 101:9%101, 1983 Tipton BK, Robertson JJ, Robertson JH: Embolism to the central nervous system from cardiac myxoma. J Neurosurg 47: 937-940, 1977 Tso MOM, Hayreh SS: Optic disc edema in raised intracranial pressure. III. A pathologic study of experimental papilledema. Arch Ophthalmol 95:1448-1457, 1977 Tso MOM, Hayreh SS: Optic disc edema in raised intracranial pressure. IV. Axoplasmic transport in experimental papilledema. Arch Ophthalmol 95:1458-1462, 1977 Unsijld R, Hoyt WF: Blickindurierte monokulaire Obskurationen bei orbitalem HPmangiom. K/in Monatsbl Augenheilkd 174:714-721, 1979 Wegener HP: Amaurosis fugax: A specific type of transient loss of vision. Illinois Med J, Jan 1957, pp 21-24 Wilkes SR, Trautmann JC, DeSanto LW, Campbell RJ: Osteoma. An unusual cause of amaurosis fugax. Mayo Clin Proc .54:25a260, 1979 Wright JE: Primary optic nerve meningioma: Clinical presentation and management. Tram Am Acad Ophthalmol Otolaryngol 83:617-624, 1977 Wright JE, Call NB, Liaricos S: Primary optic nerve meningioma. Br J Ophthalmol 64:553-558, 1980 Zappia RJ, Winkelman JZ, Gay AJ: Intraocular pressure changes in normal subjects and the adhesive muscle syndrome. Am J Ophthalmol 71:880, 1971 with elevated
27. Sossi N, Anderson
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Reprint requests should be addressed to Dr. Riri S. Manor, Neuro-ophthalmological Unit, Department of Ophthalmology, Beilinson Hospital, Petah Tiqva 49100, Israel.
Abstract. A 54-year-old man with a past history of hypertension, diabetes mellitus, hypercholesterolemia and two myocardial infarctions presented with repeated attacks of amaurosis fugax in the right eye. The fact that the amaurosis occurred only on downward gaze is sufficient evidence to exclude carotid atheromatous disease and to imply an orbital etiology. (SU~V Opthalmol 31:41 l-416, 1987)
Key words.
amaurosis
fugax
l
SIRA
gaze-evoked visual obscuration
l
orbit
l
tumor
CLINICAL
VOLUME 31 . NUMBER 6
l
MAY-JUNE 1967
CHALLENGES
RONALD M. BURDE, EDITOR
Amaurosis Fugax at Downward
Gaze
RIRI S. MANOR, M.D., AND ISAAC BEN SIRA, M.D. Comments by Jeffrey G. Odel, M.D., Steven A. Newman, M.D., and Lyn A. Sedwick, M.D.
The Neuro-ophthalmological
Unit, Department of Ophthalmology, Be&son
Hospital, Petah Tigva, Tel Aviv University, Israel
(In keeping with the purpose of a clinical pathological conference, the abstract and kc? words appear at the end of the article.)
right visual field demonstrated an enlarged blind spot and a lower inferior arcuate scotoma breaking out into a lower nasal step. There was a slight concentric contraction of the field in the left eye. The intraocular pressures were 16 mm Hg in each eye. Ophthalmoscopy revealed that the right disc was hyperemic and elevated with marginal splinter hemorrhages. The arterial and venous trees were normal in both eyes. A diagnostic procedure was performed.
Case Report. In June 1983, a 54-year-old man was sent to the Neuro-ophthalmological Unit for evaluation regarding the diagnosis: “Right amaurosis fugax due to carotid insufficiency most probable. Papilledema due to hypertensive disease.” His history included arteriosclerotic cardiovascular disease, two myocardial infarctions, hypertension, hypercholesterolemia and diabetes mellitus. The patient described his symptoms of the last few months as, “a transitory loss of the vision in the right eye when I look down suddenly.” An Amsler grid at reading distance in primary position or placed above the patient’s forehead was clearly seen; however, when the patient was asked to look from the primary position to an Amsler grid placed in the normal reading position, he claimed that the grid totally disappeared for a few seconds and then gradually reappeared from above downward “like a curtain” (Fig. 1). This phenomenon was reproducible. Examination revealed a visual acuity of 20/25 in the right eye and 20120 in the left. There was a relative afferent pupillary defect on the right, and brightness was interpreted as being 70% as bright in the right eye as in the left eye. The eyes were white and quiet, and there was no proptosis. The extraocular motility examination was normal. The
What is your dlyerential What diagnostic
diagnosis?
studies would you recommend?
Comments Comments By Jeffig G. Odel, M.D., Neuro-ophthalmology, Columbia-Presbyterian Medical Center, New York, New York For several months this 54-year-old man experienced obscurations of vision in the right eye upon assuming a downward gaze position. In each episode the visual image disappeared for a few seconds and then reappeared from above while the eye was in downward gaze. Examination of the right eye revealed mild depression of visual acuity, an arcuate scotoma, an enlarged blind spot, an afferent pupillary defect, and an elevated hyperemic disc with splinter hemorrhages. In view of his history of hy411
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Fig. 1. The visual obscuration noted on downward gaze is illustrated by means of the Amsler grid chart. 1. Initial total loss ofvision. 2 & 3. Recovery ofvision in stages from above downward.
pertension, diabetes, myocardial infarctions and hypercholesterolemia these episodes were presumed to represent transient ocular ischemic attacks, presumably hypotensive or embolic of carotid or cardiac origin.7,‘&‘%32 The differential diagnosis in this case must take into consideration transient monocular blindness in the presence of disc swelling and signs of optic nerve dysfunction. The differential diagnosis of amaurosis fugax depends on the duration and circumstances of symptoms, pattern of visual loss, and associated findings. 18,1gAttacks lasting seconds with an iris diaphragm pattern of visual field constriction, perhaps triggered by a postural change or carotid compression, suggest hypoperfusion. Attacks lasting 2 to 20 minutes with quadrantic, altitudinal, sequential or sudden total visual field loss, occasionally associated with fleeting photopsia, suggest emboli. Fundus examination may reveal these emboli or sheathing of the retinal vessels, suggesting their previous pasarteritis may present with transage. I5319Temporal sient monocular obscurations on standing or sitting which resolve on lying down.17 Patients with embolic or hypoperfusion amaurosis fugax (of carotid or cardiac origin) usually .do not have gaze-evoked attacks, swollen disc or signs of optic nerve dysfunction. Another frequent cause of transient visual loss, though unlikely in this case, is classic migraine.” It causes a binocular scintillating fortification scotoma typically starting paracentrally and expanding and migrating eccentrically, lasting up to 30 minutes.5~22 As the visual phenomenon passes headache may follow, though after many years of migraine it may not be as apparent and the visual phenomena may appear by themselves in the elderly.4~8~22Ocular migraine with retinal or choroidal ischemia is monocular and may be indistinguishable from embolic or hypotensive amaurosis fugax. In the patient under
MANOR,
BEN SIRA
35 years old transient monocular visual loss without other obvious cause is frequently attributed to ocular migraine. Infrequently it may result in fixed deficit, i.e., retinal artery occlusion or ischemic optic neuropathy where the disc appears swollen; however, amaurosis fugax in migraine is not gaze-induced. The most frequent cause of swollen discs and transient visual loss is papilledema, i.e., swollen discs on the basis of elevated intracranial pressure. It may be associated with transient visual obscurations lasting seconds3 and may be asymmetric and occasionally unilateral. The obscurations may be either monocular or binocular, may be posturally related,3,13s14 and have been ascribed to transient insufficiency of optic nerve perfusion.26 Since the perfusion pressure is the difference between capillary pressure and tissue pressure, transient changes in either can lead to visual obscuration. intracranial pressure which is High transmitted within the optic nerve sheath can lead to elevated intraneural tissue pressure in the optic nerve head by causing axoplasmic flow obstruction and venous congestion26~2g~30 so that transient drops in optic nerve head capillary pressure may readily result in obscurations. However, the obscurations of papilledema are not described as gaze-evoked, and this patient has no findings suggestive of elevated intracranial pressure. Transient obscurations similar to those seen in papilledema have been reported with other causes of acquired disc swelling, such as disc edema from optic nerve sheath meningioma and ocular inflammation. Elevated intraneural tissue pressure compromising optic nerve head perfusion is believed to be the basis here as well as in papilledema. Anomalies of the optic nerve head, e.g., optic nerve head drusen and tilted discs which may be mistaken for acquired disc swelling, may have obscurations on the same basis.26 This patient’s obscurations OCcurred in the presence of disc edema but were gazeevoked. Theoretically, if intraocular pressure were elevated on downward gaze from a muscle restriction36 it could further decrease perfusion pressure and lead to visual obscuration. Gaze-evoked visual loss has been reported with orbital mass lesions.‘,1’,3’~33-35This was first reported man with primary by Wright34,35 in a 37-year-old optic nerve sheath meningioma, good vision, no proptosis and a swollen disc. It has been reported subsequently with intraconal cavernous hemangioma,1,31 extraconal osteoma,33 and zygomatic fracture.” The patients reported with gaze-evoked blindness have all been under 40 years of age. Visual acuity between attacks is usually normal or mildly abnormal. The visual field reflects the state of the disc and
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optic nerve compromise, which is usually mild. The degree of proptosis varies from none to moderate. An afferent pupillary defect may or may not be present in primary gaze positions and may appear on assuming the appropriate gaze position. Gazeevoked blindness has been encountered on abduction, depression and adduction. Although the amaurosis is usually described as persisting if the eye remains in the eccentric gaze position, in this patient vision returned although eccentric gaze was maintained. The amaurosis has variously been attributed to constriction of the central retinal artery at its entry into the optic nerve by the tumor combined with elevated intraocular pressure, e.g., on assuming the appropriate gaze position,35 acute venous obstruction affecting the retina,’ or to a local circulatory disturbance in the intraconal optic nerve.“’ The rapid onset, clearing and brief duration of this patient’s obscuration, triggered by the mechanical stimulus of ocular rotation, is compatible with a vascular etiology. The occurrence on downward gaze and the presence of elevated disc suggest an intraorbital lesion. He most likely harbors an intraorbital mass, probably intraconal, which on downward gaze is compromising either optic nerve or retinal circulation. Given previous reports, the causative lesions probably would be optic nerve meningioma or hemangioma. At this point, a high resolution axial or coronal CT scan of the orbits with contrast is indicated to look for an orbital tumor. Fluorescein angiography might help to delineate the mechanism underlying the visual loss. Comments By Steven A. Newman, M.D., Departments of ~phtha~rno~o~ and Neurotogicat Surgery, University of Virginia, Charlottesville, Virginia This case of a 54-year-old man raises the interesting discussion of gaze-evoked transient visual disturbances. Clinically, we often distinguish visual loss by its duration. Episodes of amaurosis fugax usually have a sudden onset and last between one and ten minutes. When the epidose duration is less than a minute, these are often referred to as transient visual obscurations. This rough clinical distinction has proven useful in suggesting the pathophysiology and possible etiology. The rapidity of onset and brisk return of normal function has always suggested a primary vascular etiology. While thrombosis can cause acute loss of vision, repeated episodes argue for other pathophysiology. Emboli to the retinal vessels may produce transient, although more likely permanent, uniocular field defects. These may be cholesterol (Hollenhorst plaque), usually arising from an atherosclerot-
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ic lesion in the neck, or less commonly, calcific, usually from a cardiac source. The classical diffuse loss of vision, however, occurs far from frequently related to showers of platelet emboli, usually arising from carotid atheromas, as described by C. Miller Fisher.’ Nonembolic vascular disease may also lead to transient visual disturbances2 Inflammation may be due to giant cell arteritis in older people and collagen vascular disease in younger. Although more frequently involving the posterior circulation, migrainous spasm may involve the retinal vessels as well, usually leading to stereotypical visual loss lasting 10 to 30 minutes. These may or may not be associated with other neurologic symptoms, including headache. Other rare vascular etiologies include hyperviscosity syndromes (macroglobulinemia) and emboli related to tumors.‘R Transient visual obscurations have classically been described in patients with papilledema. While some of the earliest authors suggested intermittent cerebral herniation with compromise of large posterior vessels,h more recent speculation centers on microvascular abnormalities at the level of the optic disc itself.‘5*23 It is believed that the swelling of the optic nerve fibers themselves3” further increases tissue pressure and compromise perfusion. While autoregulation usually maintains a careful balance intraocular, and tissue presbetween perfusion, sures,‘0~27 this may be altered in the setting of disc edema. Anything that then transiently decreases perfusion (drop in arterial blood pressure) or increases pressure at the disc (increased intraocular pressure?O) may result in temporary optic nerve dysfunction. This increased susceptibility to transient disturbances and vascular equilibrium would explain the frequent occurrence of transient visual obscurations with change in position (suddenly arising or stooping). Small drops in systemic arterial pressure or increase in intracranial pressure with subsequent increase in venous outflow pressure might well play a role. Transient visual obscurations have been reported frequently in patients with intracranial mass lesions.6 Most of these cases, we now feel, were related to disc edema. Transient visual obscurations in a select population with papilledema have been reported to occur in 60% or more and with episodes occurring up to 50 times per day.‘” Intracranial mass lesions may also produce visual loss by direct or indirect compression of the optic nerve. Two of Cogan’s 25 patients with blackouts not due to carotid occlusive disease were related to intracranial tumors.3 More recently, Hilton-Jones and associatesI reported two frontal lobe tumors (one astrocytoma and one meningioma) presenting with transient vis-
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ual loss unassociated with disc swelling. FrisCn and coworkers9 described a cystic craniopharyngioma which repeatedly caused visual loss related to reaccumulation of fluid. All of these episodes, however, lasted for longer periods of time. In the case of the frontal lobe tumors, it is thought that direct pressure may be applied to the optic nerve, either by the tumor itself or by herniation of the gyrus rectus beneath the falx. In 1979 Unsold and Hoyt3’ described a 29-yearold patient with monocular obscurations of vision evoked by right lateral gaze. A CT scan revealed an intraconal hemangioma. A second patient with gaze-evoked blackouts was reported by Brown and Shields in 1981.’ The patient described “haziness” progressing to “complete blackout” with progressive downward gaze, again related to a hemangioma. More recently, Dr. Ivor Levy and Dr. James Orcutt and associates each presented six cases of gaze-evoked amaurosis fugax at the Sixth Meeting of the International Neuro-Ophthalmology Society in Hakone, Japan (June, 1986). In all of the patients studied an intraorbital tumor could be demonstrated. Six of the 12 patients had meningiomas. There were three hemangiomas, one myoblastoma, one optic nerve glioma, and one undetermined mass. All three of Orcutt’s patients with meningiomas had optociliary shunt vessels. There did not appear to be a substantial increase in intraocular pressure associated with gaze-evoked visual dropout. This would suggest that microvascular hypoperfusion occurs either due to direct compression of the small vessels to the nerve itself, or possibly related to increased venous outflow obstruction and thus imbalance in perfusion pressure at the disc. Interestingly, gaze-evoked amaurosis fugax may occur with disc edema unassociated with an orbital tumor or increased intracranial pressure. Sadun and colleaguesz6 reported a patient with transient visual obscurations when looking to the left. In this patient, the disc swelling was believed to be related to inflammation with no evidence of mass lesion on CT scan. In the case presented here, the asymmetric disc swelling would make increased intracranial pressure or toxic etiologies far less likely. Of the three leading causes of unilateral disc swelling (mass leischemia, and inflammasion with compression, tion), the relative preservation of central visual acuity would be less likely in optic neuritis. While an intraorbital mass lesion would be most commonly expected to produce proptosis, this is not always the case. In particular, optic nerve sheath meningiomas and other slowly growing tumors around the optic nerve may often occur without proptosis. These, also, may produce transient visual 10~s.~Unsold and
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Hoyt’s patient3’ was said to have “minimal proptosis,” and of 66 patients with orbital hemangiomas, Harris and Jakobiec I2 described no proptosis in 28%. Thus, first on my list of differential diagnoses would be that of an intraconal orbital mass lesion, most likely a hemangioma or possibly meningioma. I could not completely exclude the possibility of anterior ischemic optic neuropathy. Disc edema, even in the absence of a mass lesion, could predispose to transient, even gaze-evoked, obscurations. Certainly our workup would include an orbital CT scan. I would expect noninvasive studies of carotid flow to be normal.
Comments By Lyn A. Sedzerick, M.D., Neuro-ophthalmology, Florida Hospital, Orlando, Florida. Amaurosis fugax may result from a number of intraocular, intraorbital, intracranial, hematologic, vasospastic or thromboembolic conditions. This patient’s likely diagnosis amply demonstrates the importance of a complete ophthalmologic evaluation of all such patients. Transient loss of vision in one eye is usually a sign of transient loss of blood supply to the optic nerve and thus may be secondary to vascular occlusion, emboli-mediated or not, or hypoperfusion of the optic nerve. Vascular occlusion may occur from emboli, cardiac or carotid, or from spasm or compression of nonoccluded vessels. Patients with embolic disease usually complain of altitudinal or total loss of vision or blur of vision lasting less than 15 minutes with complete resolution. Sometimes plateletfibrin, cholesterol or calcific emboli may be seen in the fundus following such an attack. These emboli are presumably bits of a larger embolus which initially clogged vessels of the optic nerve and caused the visual loss before breaking up and moving downstream into the eye. Patients with vasospastic vascular occlusion, usually retinal migraine, may be seen to have attenuated retinal arterioles during an attack which may give symptoms identical to those produced by embolic vascular occlusion. Direct compression of nonoccluded vessels in the optic nerve, e.g., from papilledema or from any mass lesion that adjoins the optic nerve, results in visual loss which is usually very brief (several seconds) and is labeled as a transient obscuration of vision. Hypotension may result in monocular or binocular transient visual loss as may hyperviscosity syndromes, both from inadequate perfusion of the optic nerve. All of these entities are very nicely discussed by Burde, Savino, and Trobe.* Occasionally transient visual loss is secondary to an anomaly of the optic nerve itself, the most common being optic nerve drusen. These spells are
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characteristically very brief. Other ocular abnormalities, such as narrow filtering angles, may rarely produce painless visual changes which resemble amaurosis fugax from carotid or cardiac diseaseez5 The mechanism of such visual loss is probably raised intraocular pressure which results in poor perfusion of the optic nerve. The patient described here underscores the importance of ophthalmic evaluation of all patients who complain of transient visual loss. His symptoms of altitudinal visual loss of brief duration only in downward gaze suggest a compressive lesion in the orbit. Examination shows signs of optic nerve dysfunction (afferent pupillary defect, visual field loss) and reveals a unilateral hyperemic disc. The most likely diagnostic possibility is an optic nerve tumor or, less likely, a compressive orbital lesion which abuts the optic nerve. Although thyroid ophthalmopathy may cause transient loss of vision in certain positions of gaze from enlarged muscles which produce a compressive optic neuropathy, other characteristic signs of the disease are universally present such as lid lag, stare, adnexal swelling, conjunctival injection over rectus muscles, proptosis and restrictive myopathy, none ofwhich this patient demonstrates. Papilledema may be unilateral and may produce brief loss of vision in one eye; however, papilledema does not produce visual field changes, except an enlarged blind spot, until long-standing and has no propensity to cause loss of vision only in certain positions of gaze. Although optic nerve glioma and optic nerve sheath meningioma usually produce either proptosis or significant visual loss, they may present with modest visual impairment, or discernible proptosis and often cause “position dependent” transient visual loss. The mechanism of such amaurosis appears to be direct compression of the nerve or its vasculature.‘+ The diagnostic procedure in this case was probably a high resolution CT scan of the orbits which can distinguish glioma from meningioma about 75% of the time.*’ In the future, magnetic resonance imaging of the orbits with the help of surface coils for better definition may be the procedure of choice for these and other orbital lesions.
Case History Footnote of the orbit disclosed the presA CT examination ence of an enhancing tumoral formation situated intraconally, lateral and somewhat superior to the right optic nerve (Fig. 2). Orbital exploration was scheduled, but the patient had a third myocardial infarction and surgery was postponed. By December, 1983, the disc edema had regressed, and optic atrophy was evident. The patient continued to complain about amaurosis fu-
Fig. 2. Orbital CT scan showing the presence of a small space-occupying lesion adjacent to the right globe.
gax on downward gaze. Over the ensuing 18 months visual acuity in the right eye gradually decreased to 20150, the visual field contracted, but the amaurosis fugax on downward gaze disappeared. Tumor size remained relatively constant on repeat CT evaluations. The neuroradiologic diagnosis was that of cavernous hemangioma. At this point in time, the patient showed no interest in surgical intervention.
References 1. Brown 2. 3. 4.
5.
6.
7. 8.
GC, Shields GA: Amaurosis fugax secondary to presumed cavernous hemangioma of the orbit. Ann Ophthalmol f3tl205-1209, 1981 Burde RM, Savino PJ, Trobe JD: Clinical Decision in NeuroOphthalmology. St Louis, CV Mosby Company, 1985, pp 91-l 15 Cogan DG: Blackouts not obviously due to carotid occlusion. Arch Ophthalmol 66:180-187, 1961 Cohen GR, Harbison JW, Blair CJ, Ochs AL: Clinical significance of transient visual phenomena in the elderly. Ophthalmologv 91:436-442, 1984 Corbett JJ: complications of migraine and _- Neuro-ophthalmic cluster headaches, in, Smith CH, Beck RW (eds): Symposium on Neuro-Obhthalmoloev. Neurolopic Clinics 1:4. Philadelphia, WB Saundeis Co, 196, pp 973r995 Ethelberg S, Jensen VA: Obscurations and further time-related paroxysmal disorders in intracranial tumors. Arch New01 Psych& 68;130-149, 1952 Fisher CM: Observations of the fundus oculi in transient monocular blindness. Neurologv 9:333-347. 1959 Fisher CM: Late-life miuaine accomoaniments as a cause of unexplained transient iscYhemic attacks‘. CanJNeurol Sci 7:%17.
1980 9. Fristn L, Sjiistrand J, Norrsell K, Lindgren S: Cyclic compression of the intracranial optic nerve: uatterns ofvisual failure and recovery. JNeurol Neuro& Psych&v 39:1109-l 113, 1976 10. Geiier C, Bill A: Effects of raised intraocular pressure on retinal, preiaminar, laminar, and retrolaminer optic nerve blood flow in monkeys. InvestOphthalmol Vir .Sci 28:1030-1042. 1979 11. Hampton GR, Krohel GB: Gaze-evoked blindness. Ann Ophtholmol 15:7>76, 1983 FA: Cavernous hemangioma of the orbit: A 12. Harris GJ, Jakobiec clinicopathologic analysis of 66 cases. in. Jakobiec FA (ed): Ocular hnd Ad&z1 Tumws. Birmingham. A&ulapius, 1978, pp 741-781 13. Hayreh SS: Optic disc edema in raised intracranial pressure. V.
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31(6) May-June
1987
MANOR,
Pathogenesis. Arch Ophthalmol 95:1553-1565, 1977 14. Hayreh SS: Optic disc edema in raised intracranial pressure. VI. Associated visual disturbances and their pathogenesis. Arch Ophthalmol95:1566-1579, 1977 15. Hayreh SS: Structure and blood supply of the optic nerve, in, Heilmann K, Richardson KT (eds): Glaucoma. Conceptions of a Disease. Pathogenesis, Diagnosis, Therapy. Stuttgart, Georg Thieme, 1978, pp 78-96 16. Hilton-Jones D, Ponsford JR, Graham N: Transient visual obscurations, without papilloedema. J Neural Neurosurg Psychiatry 45:832-834, 1982 17. Hollenhorst RW: Effect of posture on retinal ischemia from temporal arteritis. Arch Ophthalmol 78:56!%577, 1967 18. Hoyt WF: Ocular symptoms and signs, in, Wylie ES, Ehrenfeld WK (eds): Extracranial Occlusive Cerebrovascular Disease: Diagnosis and Management. Philadelphia, WB Saunders, 1970, pp 64-95 19. Hoyt WF: Retinal ischemic symptoms in cardiovascular diagnosis. Postgrad Med October, 1972, pp 85-90 20. Jaeger EA, Severs RJ, Weeks SD, Duane TD: Visual field changes during positive acceleration. Aerospace Med 35:96%972, 1964 21, Jakobiec FA, Depot MJ, Kennerdell JS, et al: Combined clinical and computed tomographic diagnosis of orbital glioma and meningioma. Ophthalmology 91: 137-155, 1984 22. Lashley KS: Patterns of cerebral integration indicated by the scotomas of migraine. Arch Neural Psychiat 46~331-339, 1941 23. Lieberman MF, Maumenee AE, Green WR: Histologic studies of the vasculature of the anterior optic nerve. Am J Ophthalmol 82:405-423, 1976 24. Miller NR: Compressive optic neuropathies with optic disc swelling, in Miller NR (ed): Walsh and Hoyt’s Clinical Neuroophthalmolou. Baltimore, William & Wilkins, 1982, 4th edition, volume 1, chapter 15, pp 24%253 25. Ravits J, Seybold ME: Transient monocular visual loss from narrow-angle glaucoma. Arch Neural 41:991-993, 1984 26. Sadun AA, Currie JN, Lessell S: Transient visual obscurations
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optic discs. Ann Neural 16:48%494, 1984 DR: Effect of elevated intraocular pressure on bloodflow. Occurrence in cat optic nerve head studied with iodoantipyrine I ‘25 Arch Ophthalmol 101:9%101, 1983 Tipton BK, Robertson JJ, Robertson JH: Embolism to the central nervous system from cardiac myxoma. J Neurosurg 47: 937-940, 1977 Tso MOM, Hayreh SS: Optic disc edema in raised intracranial pressure. III. A pathologic study of experimental papilledema. Arch Ophthalmol 95:1448-1457, 1977 Tso MOM, Hayreh SS: Optic disc edema in raised intracranial pressure. IV. Axoplasmic transport in experimental papilledema. Arch Ophthalmol 95:1458-1462, 1977 Unsijld R, Hoyt WF: Blickindurierte monokulaire Obskurationen bei orbitalem HPmangiom. K/in Monatsbl Augenheilkd 174:714-721, 1979 Wegener HP: Amaurosis fugax: A specific type of transient loss of vision. Illinois Med J, Jan 1957, pp 21-24 Wilkes SR, Trautmann JC, DeSanto LW, Campbell RJ: Osteoma. An unusual cause of amaurosis fugax. Mayo Clin Proc .54:25a260, 1979 Wright JE: Primary optic nerve meningioma: Clinical presentation and management. Tram Am Acad Ophthalmol Otolaryngol 83:617-624, 1977 Wright JE, Call NB, Liaricos S: Primary optic nerve meningioma. Br J Ophthalmol 64:553-558, 1980 Zappia RJ, Winkelman JZ, Gay AJ: Intraocular pressure changes in normal subjects and the adhesive muscle syndrome. Am J Ophthalmol 71:880, 1971 with elevated
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Reprint requests should be addressed to Dr. Riri S. Manor, Neuro-ophthalmological Unit, Department of Ophthalmology, Beilinson Hospital, Petah Tiqva 49100, Israel.
Abstract. A 54-year-old man with a past history of hypertension, diabetes mellitus, hypercholesterolemia and two myocardial infarctions presented with repeated attacks of amaurosis fugax in the right eye. The fact that the amaurosis occurred only on downward gaze is sufficient evidence to exclude carotid atheromatous disease and to imply an orbital etiology. (SU~V Opthalmol 31:41 l-416, 1987)
Key words.
amaurosis
fugax
l
SIRA
gaze-evoked visual obscuration
l
orbit
l
tumor