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Orbital Infarction Syndrome after Surgery for Intracranial Aneurysms
Orbital Infarction Syndrome after Surgery for Intracranial Aneurysms Carol F. Zimmerman, MD/ Peter D. Van Patten, MD,Z Karl C. Golnik, MD/ Thomas A. Kopitnik, Jr., MD, 4 Rajiv Anand, MD1 Background: Global orbital infarction results from ischemia of the intraocular and intraorbital structures due to hypoperfusion of the ophthalmic artery and its branches. Patients: The authors describe six patients in whom acute proptosis, ophthalmoplegia, and blindness developed immediately after surgery for intracranial aneurysms. Results: All patients underwent standard frontotemporal craniotomies to clip their aneurysms. In all patients, proptosis, ophthalmoplegia, and blindness developed in the immediate postoperative period; fundus abnormalities included retinal edema, retinal arteriolar narrowing and other vascular abnormalities, and pale optic disc swelling. Some patients had facial and corneal anesthesia. Ophthalmoplegia and facial anesthesia improved in most patients, but none regained any vision in the affected eye. Conclusion: Orbital infarction syndrome is a rare complication of neurosurgical procedures. Increased orbital pressure probably reduced ophthalmic artery and collateral arterial perfusion, resulting in ischemia of the intraocular and intraorbital structures. There may be multiple factors that compound the risk for orbital infarction, and patients with subarachnoid hemorrhage, increased intracranial pressure, anomalous arterial or venous circulation, or impaired orbital venous outflow seem particularly vulnerable. Ophthalmology 1995; 102:594-598
Global orbital infarction is a rare disorder resulting from ischemia of all the intraocular and intraorbital structures due to occlusion of the ophthalmic artery and its branches. The syndrome can occur with common carotid occlusion, Originally received: July 5, 1994. Revision accepted: November 23, 1994. 1 Department of Ophthalmology, University of Texas, Southwestern Medical Center at Dallas, Dallas. 2 Department of Ophthalmology and Neurology, Southern Illinois University School of Medicine, Springfield. 3 Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston. 4 Department of Neurosurgery, University of Texas, Southwestern Medical Center at Dallas, Dallas. Presented in part as a poster at the American Academy of Ophthalmology Annual Meeting, Anaheim, October 1991. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc, New York, New York. Reprint requests to Carol F. Zimmerman, MD, Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75235-9057.
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orbital mucormycosis, giant cell arteritis, and myelofibrosis, but is not widely recognized as a complication of surgery. 1- 3 We report six patients with acute unilateral visual loss and proptosis after clipping of cerebral aneurysms. Retinal and choroidal nonperfusion, ophthalmoplegia, and facial anesthesia suggested hypoperfusion of the ophthalmic artery and its branches, consistent with orbital infarction.
Case Reports Case 1. A 36-year-old man had sudden headache, lethargy,
and seizures. Computed tomography (CT) showed subarachnoid blood in the suprasellar cistern; cerebral arteriography demonstrated a ruptured anterior communicating artery aneurysm and agenesis of the proximal right anterior cerebral artery. The aneurysm was clipped via a left frontotemporal craniotomy. Immediately after surgery, left proptosis and chemosis developed. The patient remained comatose 18 hours after surgery. The left pupil was 5 mm and nonreactive to direct or consensual
Zimmerman et al · Orbital Infarction Syndrome
Figure 1. Case 1. Seventeen days after surgery, the left eye remains proptotic, with ptosis, chemosis, and total ophthalmoplegia. A left adduction deficit is demonstrated here as the patient looks to the right.
light, with a 4+ left relative afferent pupillary defect. He had left proptosis and chemosis, and intraocular pressures (lOPs) were 12 mmHg in the right eye and 15 mmHg in the left. The left fundus showed retinal edema throughout the posterior pole and midperiphery, with a serous retinal detachment, and a cherry-red spot. The retinal veins were enlarged, and there were scattered blot hemorrhages. The right eye was normal. Topical levobunolol and systemic acetazolamide were started, and the patient later received intravenous pulse methylprednisolone. Computed tomography showed left proptosis with preseptal soft tissue densities but no intraorbital hemorrhage or cavernous sinus abnormalities. Nine days after surgery, indirect fluorescein ophthalmoscopy showed central retinal artery occlusion and widespread retinal and choroidal nonperfusion. The proptosis gradually improved, and 17 days after surgery the patient's visual acuity was 20/20 in the right eye and no light perception in the left. He had complete left internal ophthalmoplegia and normal forced ductions (Fig 1). The optic disc was pale, and the retinal vessels were attenuated. The subretinal fluid had partially resolved, and diffuse retinal pigment epithelial disturbance was evident (Fig 2). The electroretinogram in the left eye was extinguished. Cerebral angiography 4 weeks later was remarkable only for the clipped aneurysm. Six weeks after surgery, he had advanced optic atrophy and pigmentary retinopathy in the left eye. Fluorescein angiography confirmed global retinal and posterior ciliary non perfusion. One year later, visual acuity was 20/15 - 2 in the right eye and no light perception in the left. He had an amaurotic left pupil and moderate limitation of upgaze in the left eye. The fundus was unchanged. Case 2. A previously healthy 39-year-old woman was found unconscious. Computed tomography showed subarachnoid blood in the basilar cisterns and intracerebral blood in the left frontal lobe. Cerebral angiography showed a ruptured left anterior communicating artery aneurysm and a right middle cerebral artery bifurcation aneurysm. She underwent a left frontotemporal craniotomy and clipping of both aneurysms, without intraoperative complications. Immediately after surgery, massive left proptosis and visual loss developed. Visual acuity was 20/20 in the right eye and no light perception in the left. The right eye and periorbita were normal. The left pupil was 5 mm and nonreactive to direct or consensual light stimulus. There was a 4+ left relative afferent pupillary defect. She had marked left proptosis, chemosis, and complete
Figure 2. Case 1. The left fundus 17 days after surgery shows arteriolar narrowing, optic atrophy, partial resolution of the subretinal fluid and retinal edema, and pigmentary retinopathy.
ophthalmoplegia. The left globe was tense by palpation, and lOP was greater than 50 mmHg. The retina and optic nerve were diffusely edematous with no retinal perfusion and no cherryred spot. The lOP in the left eye was reduced promptly to 25 mmHg by lateral canthotomy, cantholysis, and anterior chamber paracentesis. Topicallevobunolol, systemic acetazolamide, and methylprednisolone were started. A CT scan showed moderate enlargement of the medial and inferior recti muscles, but no intraorbital hemorrhage. Cerebral arteriography was remarkable only for the clipped aneurysms. Five days later, the proptosis had improved, but the chemosis and ophthalmoplegia persisted. Magnetic resonance imaging demonstrated extraocular muscle enlargement and persistent left frontal hematoma but no evidence of cavernous sinus or other venous thrombosis (Fig 3). Vision in the left eye was no light perception, and the left optic nerve was pale. The retinal vessels remained markedly attenuated, and diffuse retinal pigmentary disturbance was evident. Fluorescein angiography showed total
Figure 3. Case 2. Five days after surgery, coronal Tl-weighted magnetic resonance imaging shows enlargement of the extraocular muscles (small arrows) and a left frontal hematoma (large arrow).
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retinal and choroidal nonperfusion, and electroretinography waveforms were nonrecordable. Three weeks later, vision in the left eye remained no light perception with a 4+ relative afferent pupillary defect. The proptosis and chemosis gradually resolved, but the ophthalmoplegia and fundus abnormalities persisted, except for minimal recovery of upgaze. Case 3. A previously healthy 29-year-old woman had sudden headache, vomiting, and neck pain. Lumbar puncture and CT confirmed subarachnoid hemorrhage, and cerebral angiography showed a left anterior communicating artery aneurysm. The aneurysm was clipped via a left frontotemporal craniotomy. Four hours later, the patient's left pupil was noted to be nonreactive to light. Three days later, visual acuity was 20/20 in the right eye and no light perception in the left. The left pupil was 1 mm larger than the right and did not react to direct light (but did have a minimal consensual reaction). There was a marked left relative afferent pupillary defect. She had moderate left periorbital edema, chemosis, proptosis, and ptosis. Adduction, depression, and elevation were moderately diminished, and no abduction was present on the left. Left upper facial and corneal sensation were absent. Anterior segments were normal. Intraocular pressures were 16 mmHg in the right eye and 17 mmHg in the left. Left retinal edema and a cherry-red spot were evident, though the retinal vessels appeared normal in both eyes. Magnetic resonance imaging showed left proptosis but symmetric cavernous sinuses and no orbital hemorrhage. Three months after surgery, the patient remained blind in the left eye. The left afferent pupillary defect persisted, but the consensual pupillary response had normalized. Her left facial anesthesia, ptosis, proptosis, and ophthalmoplegia had completely resolved. The left optic disc was pale, and the retinal vessels were markedly attenuated. Case 4. A 55-year-old man with hypertension who was acutely comatose had subarachnoid hemorrhage on CT. His angiogram showed a right anterior communicating artery aneurysm which was clipped using a right frontotemporal approach. Three hours later, an unreactive right pupil and right ptosis were recorded. Two days later, vision was hand motions in the right eye and 20/50 in the left. The right pupil was minimally reactive to direct light with a marked relative afferent pupillary defect. There was a minimal right consensual pupillary response. Striking right proptosis, chemosis, and complete ptosis were present, and right upper facial and corneal sensation were diminished. Right eye ductions were absent. Intraocular pressures were 17 mmHg in the right eye and 18 mmHg in the left. The right retina was edematous, and there were scattered posterior pole blot hemorrhages. No cherry-red spot was evident, and the retinal vessels were normal. New findings on CT included a small right posterior frontal infarction and right orbital soft tissue swelling with proptosis. No orbital hemorrhage or cavernous sinus abnormalities were present. One month later, visual acuity was no light perception in the right eye and 20/20 in the left. The right afferent pupillary defect persisted, but the consensual response had normalized. His ptosis, chemosis, proptosis, and facial anesthesia had resolved, and motility had improved in the right eye. There was marked right retinal vascular attenuation, a pale optic disc, and diffuse pigmentary retinopathy. Six months later, ductions had normalized, but results of the examination otherwise were unchanged. Case 5. A 56-year-old woman with hypertension was found to have ophthalmoplegia due to thyroid orbitopathy and ocular myasthenia gravis. An incidental aneurysm of the right middle cerebral artery trifurcation was identified by magnetic resonance imaging, and she underwent elective aneurysm clipping via a right frontotemporal craniotomy.
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Upon arrival in the recovery room, the patient had right ptosis, proptosis, and ophthalmoplegia. Three hours later, she was still drowsy but visual acuity was no light perception in the right eye and 20/400 in the left. The right pupil did not react to light and there was no consensual response. A 4+ right relative afferent pupillary defect was present. There was complete right ptosis and ophthalmoplegia, marked chemosis, and 5 mm of right proptosis. Right upper facial and corneal sensation were absent. Intraocular pressures were 28 mmHg in the right eye and 13 mmHg in the left. Results of funduscopy showed retinal edema, arteriolar attenuation, and a cherry-red spot in the right eye. The lOP was treated with ocular massage and acetazolamide, timoptic, and paracentesis. Her CT scan showed a small right frontal infarction and right orbital soft tissue swelling with proptosis. Three weeks later, the right retinal edema had resolved but visual acuity was no light perception in the right eye and 20/25 in the left. The vertical ductions of the right eye had improved slightly. Three months later, visual acuity was unchanged, and the right afferent pupillary defect persisted. The external appearance and eye movements had returned to preoperative baseline. The right optic disc was pale, and the retinal vessels were attenuated. Case 6. A 74-year-old woman had acute headache, nausea, vomiting, and mental status changes 1 week before admission. A CT scan demonstrated an enhancing mass in the interpeduncular fossa, and the cerebrospinal fluid confirmed subarachnoid hemorrhage. Angiography showed a large basilar apex aneurysm and absence of the right posterior communicating artery. She underwent left frontotemporal craniotomy complicated by a small amount of intraoperative bleeding. On arrival to the intensive care unit after surgery, the patient was comatose. Both pupils were 5 mm and nonreactive. Within minutes, massive right-sided proptosis developed with subconjunctival hemorrhage. The right globe and orbit were rock hard by palpation; the cornea was clear and the anterior chamber was of moderate depth. The right pupil was 5 mm and nonreactive to direct or consensual light. There was total ophthalmoplegia and lagophthalmos of the right eye. Results of funduscopic examination showed a pale optic nerve and retinal artery nonperfusion in the right eye. The left pupil was 5 mm and nonreactive. Except for slight sparing of abduction, left eye ductions were absent. The left fundus showed only atherosclerotic changes. Intravenous acetazolamide and topical apraclonidine were administered as a right lateral canthotomy and cantholysis were performed. The right eye and orbit immediately softened, and the retina reperfused. Ten minutes after the above interventional measures, lOPs were 5 mmHg in the right eye and 8 mmHg in the left. Emergency CT of the head and orbit showed tenting of the posterior orbital wall on the right, with some stretching of the right optic nerve. There was preseptal soft tissue density, but no evidence of retrobulbar blood, optic nerve sheath hematoma, orbital mass, or enlarged extraocular muscles. Postoperative changes, including a small pneumocephalus, a thin collection of extra-axial fluid about the right frontal convexity, and mild right frontal edema with slight right-to-left shift, were seen. In addition, old right middle cerebral and right posterior cerebral artery infarctions were noted. No intraparenchymal blood was seen. The patient never regained consciousness after surgery. The right proptosis quickly resolved, though the ophthalmoplegia remained. The right fundus showed perfusion of the arteries and veins, though they were markedly attenuated. The right optic disc was pale and slightly swollen, with a small amount of subretinal fluid at the posterior pole. One week later, the disc edema
Zimmerman et al · Orbital Infarction Syndrome was resolving, and early retinal pigment epithelial abnormalities were evident. A CT showed no recurrent subarachnoid blood, though new bilateral thalamic infarctions were seen. Further diagnostic procedures and treatment were deferred at the family's request. Three weeks after surgery, her right fundus was unchanged. The right pupil was nonreactive to direct or consensual light. The left pupil was sluggishly reactive, and there was a 4+ right relative afferent pupillary defect. Extraocular movements were absent in both eyes. The patient died after transfer to an extended care facility, and permission for postmortem examination was denied.
Discussion The ophthalmic artery originates from the internal carotid artery and has numerous ocular and orbital branches, including the central retinal and ciliary arteries. Visual loss after orbital infarction results from retinal infarction (due to hypoperfusion of the central retinal artery) and from anterior ischemic optic neuropathy and choroidal ischemia (both due to compromise of the posterior ciliary arteries). Ophthalmoplegia results from impaired blood supply to the extraocular muscles or ocular motor nerves, and anterior segment ischemia from hypoperfusion of the long ciliary arteries. Because of the rich collateral circulation between the branches of the external carotid and ophthalmic arteries, ophthalmic artery occlusion alone does not cause this syndrome. However, if collateral blood flow is compromised by other factors, orbital infarction may develop. The clinical features of these patients are remarkably similar. All but one patient had otherwise uncomplicated surgery. Four patients had an anterior communicating aneurysm and one patient each had a basilar and middle cerebral aneurysm, but a frontotemporal approach was used in all six patients. Five of the six had subarachnoid hemorrhage, and one patient had elective surgery for an asymptomatic aneurysm. In all patients, unilateral proptosis, ophthalmoplegia, and blindness developed ipsilateral to the craniotomy immediately after surgery. Three patients had transient numbness in the cutaneous distribution of the ophthalmic nerve and ipsilateral corneal anesthesia. Retinal edema in the perioperative period was followed within weeks by retinal artery attenuation, pigmentary retinopathy, and optic disc pallor. Most patients recovered some ocular motility but all remained blind in the affected eye. Visual acuity could never be evaluated subjectively in case 6, but the presence of a 4+ relative afferent pupillary defect on indirect testing suggested no light perception. Initial and follow-up funduscopic examinations of all six patients were consistent with retinal and choroidal infarction. Limitation of motility with proptosis may be due to mechanical restriction, ischemia of the extraocular muscles and their nerve supply, or a combination of both. In our patients, some limitation of motility persisted after forced ductions became negative, suggesting a residual ischemic deficit. Ocular motility recovered or improved in five patients. In case 6, the presence of a third nerve
paresis on the contralateral side and an aneurysm in the interpeduncular fossa suggested the possibility of an oculomotor nuclear and/or fascicular lesion that could not be distinguished from that due to orbital infarction on clinical examination alone. Chronic anterior segment ischemia did not develop in any of the patients. Ophthalmic artery occlusion is characterized by severe visual loss, frequently to no light perception. Acutely, there is diffuse opacification of the retina due to edema. The retinal arteries may be attenuated, and there is variable absence of a cherry-red macula. Fluorescein angiography demonstrates retinal and choroidal nonperfusion and the electroretinogram is nonrecordable. Late fundus findings include diffuse pigmentary retinopathy, attenuated retinal vessels and optic atrophy. In contrast, patients with central retinal artery occlusion alone usually have counting fingers vision, and fluorescein angiography demonstrates choroidal filling due to sparing of the ciliary arteries. Preservation of the choroidal circulation is evident by the normal color of the choroid underlying the macula (the cherry-red spot), surrounded by pale edematous retina. Electroretinography shows extinction of the A-wave with preservation of the B-wave. 4 Ophthalmic rather than central retinal artery hypoperfusion was supported by typical fluorescein angiograms and electroretinograms in cases 1 and 2 and by typical fundus abnormalities in all patients. Hollenhorst et al 5 reported eight patients who were blind immediately after neurosurgical procedures. All patients had retinal ischemia, and five patients had proptosis, orbital congestion, and ophthalmoplegia. Five patients with proptosis remained blind or had hand motions vision. The authors postulated that increased orbital pressure from the direct contact of the affected eye by the face rest collapsed the orbital veins and arteries. This caused congestion and proptosis and lowered the ocular perfusion pressure with resulting ocular ischemia. Reduced blood pressure may have compounded the hypoperfusion in some patients. The authors produced similar findings of retinal and choroidal ischemia by exerting pressure on the globes of rhesus monkeys while inducing hypovolemia and hypotension. Visual loss is a rare complication of surgery of many specialties; procedures requiring general anesthesia and cardiopulmonary bypass, or those in which hypovolemia, hypotension, or hypothermia occur, are particularly at risk. 5- 11 Direct pressure on the globe due to improper positioning of the patient may be responsible for postoperative visual loss in some patients. 5 •6 •12•13 Jayam et al 14 describe a patient with irreversible unilateral ischemic retinopathy and peroneal neuropathy, after a period of deep, alcohol-induced stupor. The patient lay face down on his left side for 6 hours, awakening with blindness in his left eye, proptosis, ophthalmoplegia, and retinal edema. The electroretinogram was nonrecordable. This case of "Saturday night retinopathy" shared many similarities to the postoperative patients; the mechanism was thought to be increased orbital pressure due to the prolonged dependent position of the patient, causing pressure on the globe and compromising the retinal and ciliary circulation.
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The frontotemporal or "pterional" craniotomy exposure requires a myocutaneous flap to be retracted anteriorly and inferiorly near the orbit. Because the flap is retracted across the zygomatic arch, it is unlikely to directly contact the eyelid or globe; however, in some circumstances this bulky flap could indirectly exert pressure on the globe, especially in individuals with "shallow" orbits or significant orbital congestion. No additional cases have occurred in one institution after routine use of a protective aluminum eye shield. Admittedly, the effectiveness of this device in this rare disorder is difficult to prove. Hayreh and Edwards 15 demonstrated in monkeys that ophthalmic artery pressure is compromised when cerebrospinal fluid pressure exceeded 35 em H 20. Orbital venous pressure was directly related to cerebrospinal fluid pressure, and a sudden fall in the cerebrospinal fluid pressure resulted in a significant decrease in the ophthalmic artery perfusion pressure. Cases 1 to 4 had ruptured anterior communicating artery aneurysms, with grade III or higher subarachnoid hemorrhage and frontal edema. In cases 4 and 5, new frontal infarctions developed and case 6 had new bithalamic infarctions in the early postoperative period. In our patients, subarachnoid hemorrhage and/ or cerebral infarction may have increased the intracranial hypertension, increasing the orbital pressure and lowering ophthalmic artery perfusion. Abrupt reduction of the intracranial pressure or possibly impaired vascular autoregulatory function (common in subarachnoid hemorrhage) also may have compromised ophthalmic artery perfusion. High lOP may compromise retinal artery and choroidal perfusion. Cases 2 and 6 had markedly elevated orbital pressure and lOPs with no perfusion of the retinal vessels; emergency measures to lower the lOP promptly restored retinal perfusion, though not before irreversible posterior ocular ischemia occurred. Case 5 had moderately elevated lOP, but no such elevation was observed in the remaining patients, despite significant exophthalmos. Increased lOP may result from direct pressure applied to the eyelids or globe, or from increased orbital pressure. It is likely that some transient increases in lOP go unnoticed, especially in patients who are critically ill in the perioperative period. The cause of orbital infarction syndrome in our patients is probably multifactorial. We believe that ophthalmic artery perfusion pressure was lowered due to the combined effects of orbital venous outflow obstruction with increased intraocular and orbital pressure. Any conditions that might aggravate these factors, such as increased intracranial pressure, external pressure on the globe, or decreased ophthalmic artery perfusion pressure by any mechanism might increase the risk for orbital infarction. Although it is unlikely that any one of these factors will result in the complete clinical picture, we speculate that these risk factors may be cumulative. Visual loss due to ophthalmic artery occlusion often is profound and irreversible, and thus every precaution should be taken to minimize known risk factors. Increased intracranial pressure should be controlled. Systemic blood
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pressure should not be precipitously lowered, and hypotension and hypovolemia should be avoided. The patient should be positioned carefully, and surgical drapes, positioning apparatus, and retracted flaps should be placed so that no pressure is exerted on the globe. Patients undergoing procedures in the prone position may be at particular risk and may benefit from an aluminum eye shield. Orbital venous outflow pathways should be preserved, and cautery near the superior orbital fissure and cavernous sinus minimized. Significant proptosis and elevated lOP should be managed aggressively. Retrobulbar or optic nerve sheath hematoma should be identified promptly, because some patients may benefit from immediate surgery. Despite aggressive treatment, prognosis for significant visual recovery after orbital infarction is poor.
References I. Borruat F-X, Bogousslavsky J, Uffer S, et al. Orbital infarction syndrome. Ophthalmology 1993; 100:562-8. 2. Bogousslavsky J, Pedrazzi PL, Borruat F-X, Regli F. Isolated complete orbital infarction: a common carotid artery occlusion syndrome. Eur Neurol 1991 ;31 :72-6. 3. Vergez A. Syndrome oculaire rare au cours d'une thrombose carotidienne spontanee (thrombose de l'artere ophthalmique). Ann Ocul 1959;192:376-84. 4. Brown GC, Magargal LE, Sergott R. Acute obstruction of the retinal and choroidal circulations. Ophthalmology 1986;93: 1373-82. 5. Hollenhorst RW, Svien HJ, Benoit CF. Unilateral blindness occurring during anesthesia for neurosurgical operations. Arch Ophthalmol 1954;52:819-30. 6. Givner I, Jaffe N. Occlusion of the central retinal artery following anesthesia. Arch Ophthalmol 1950;43:197-201. 7. Johnson MW, Kincaid MC, Trobe JD. Bilateral retrobulbar optic nerve infarctions after blood loss and hypotension. A clinicopathologic case study. Ophthalmology 1987;94:157784. 8. Chisholm lA. Optic neuropathy of recurrent blood loss. Br J Ophthalmol 1969;53:289-95. 9. Cove DH, Seddon M, Fletcher RF, Dukes DC. Blindness after treatment for malignant hypertension. Br Med J 1979;2:245-6. 10. Larkin DFP, Connolly P, Magner JB, et al. Intraocular pressure during cardiopulmonary bypass. Br J Ophthalmol 1987;71: 177-80. II. Sweeney PJ, Breuer AC, Selhorst JB, et al. Ischemic optic neuropathy: a complication of cardiopulmonary bypass surgery. Neurology 1982;32:560-2. 12. Wolfe SW, Lospinuso MF, Burke SW. Unilateral blindness as a complication of patient positioning for spinal surgery. A case report. Spine 1992;17:600-5. 13. Slocum HC, O'Neal KC, Allen CR. Neurovascular complications from malposition on the operating table. Surg Glynecol Obstet 1948;86:729-34. 14. Jayam AV, Hass WK, Carr RE, Kumar AJ. Saturday night retinopathy. J Neurol Sci 1974;22:413-18. 15. Hayreh SS, Edwards J. Ophthalmic arterial and venous pressures. Effects of acute intracranial hypertension. Br J Ophthalmol 1971 ;55:649-63.
Global orbital infarction is a rare disorder resulting from ischemia of all the intraocular and intraorbital structures due to occlusion of the ophthalmic artery and its branches. The syndrome can occur with common carotid occlusion, Originally received: July 5, 1994. Revision accepted: November 23, 1994. 1 Department of Ophthalmology, University of Texas, Southwestern Medical Center at Dallas, Dallas. 2 Department of Ophthalmology and Neurology, Southern Illinois University School of Medicine, Springfield. 3 Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston. 4 Department of Neurosurgery, University of Texas, Southwestern Medical Center at Dallas, Dallas. Presented in part as a poster at the American Academy of Ophthalmology Annual Meeting, Anaheim, October 1991. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc, New York, New York. Reprint requests to Carol F. Zimmerman, MD, Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75235-9057.
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orbital mucormycosis, giant cell arteritis, and myelofibrosis, but is not widely recognized as a complication of surgery. 1- 3 We report six patients with acute unilateral visual loss and proptosis after clipping of cerebral aneurysms. Retinal and choroidal nonperfusion, ophthalmoplegia, and facial anesthesia suggested hypoperfusion of the ophthalmic artery and its branches, consistent with orbital infarction.
Case Reports Case 1. A 36-year-old man had sudden headache, lethargy,
and seizures. Computed tomography (CT) showed subarachnoid blood in the suprasellar cistern; cerebral arteriography demonstrated a ruptured anterior communicating artery aneurysm and agenesis of the proximal right anterior cerebral artery. The aneurysm was clipped via a left frontotemporal craniotomy. Immediately after surgery, left proptosis and chemosis developed. The patient remained comatose 18 hours after surgery. The left pupil was 5 mm and nonreactive to direct or consensual
Zimmerman et al · Orbital Infarction Syndrome
Figure 1. Case 1. Seventeen days after surgery, the left eye remains proptotic, with ptosis, chemosis, and total ophthalmoplegia. A left adduction deficit is demonstrated here as the patient looks to the right.
light, with a 4+ left relative afferent pupillary defect. He had left proptosis and chemosis, and intraocular pressures (lOPs) were 12 mmHg in the right eye and 15 mmHg in the left. The left fundus showed retinal edema throughout the posterior pole and midperiphery, with a serous retinal detachment, and a cherry-red spot. The retinal veins were enlarged, and there were scattered blot hemorrhages. The right eye was normal. Topical levobunolol and systemic acetazolamide were started, and the patient later received intravenous pulse methylprednisolone. Computed tomography showed left proptosis with preseptal soft tissue densities but no intraorbital hemorrhage or cavernous sinus abnormalities. Nine days after surgery, indirect fluorescein ophthalmoscopy showed central retinal artery occlusion and widespread retinal and choroidal nonperfusion. The proptosis gradually improved, and 17 days after surgery the patient's visual acuity was 20/20 in the right eye and no light perception in the left. He had complete left internal ophthalmoplegia and normal forced ductions (Fig 1). The optic disc was pale, and the retinal vessels were attenuated. The subretinal fluid had partially resolved, and diffuse retinal pigment epithelial disturbance was evident (Fig 2). The electroretinogram in the left eye was extinguished. Cerebral angiography 4 weeks later was remarkable only for the clipped aneurysm. Six weeks after surgery, he had advanced optic atrophy and pigmentary retinopathy in the left eye. Fluorescein angiography confirmed global retinal and posterior ciliary non perfusion. One year later, visual acuity was 20/15 - 2 in the right eye and no light perception in the left. He had an amaurotic left pupil and moderate limitation of upgaze in the left eye. The fundus was unchanged. Case 2. A previously healthy 39-year-old woman was found unconscious. Computed tomography showed subarachnoid blood in the basilar cisterns and intracerebral blood in the left frontal lobe. Cerebral angiography showed a ruptured left anterior communicating artery aneurysm and a right middle cerebral artery bifurcation aneurysm. She underwent a left frontotemporal craniotomy and clipping of both aneurysms, without intraoperative complications. Immediately after surgery, massive left proptosis and visual loss developed. Visual acuity was 20/20 in the right eye and no light perception in the left. The right eye and periorbita were normal. The left pupil was 5 mm and nonreactive to direct or consensual light stimulus. There was a 4+ left relative afferent pupillary defect. She had marked left proptosis, chemosis, and complete
Figure 2. Case 1. The left fundus 17 days after surgery shows arteriolar narrowing, optic atrophy, partial resolution of the subretinal fluid and retinal edema, and pigmentary retinopathy.
ophthalmoplegia. The left globe was tense by palpation, and lOP was greater than 50 mmHg. The retina and optic nerve were diffusely edematous with no retinal perfusion and no cherryred spot. The lOP in the left eye was reduced promptly to 25 mmHg by lateral canthotomy, cantholysis, and anterior chamber paracentesis. Topicallevobunolol, systemic acetazolamide, and methylprednisolone were started. A CT scan showed moderate enlargement of the medial and inferior recti muscles, but no intraorbital hemorrhage. Cerebral arteriography was remarkable only for the clipped aneurysms. Five days later, the proptosis had improved, but the chemosis and ophthalmoplegia persisted. Magnetic resonance imaging demonstrated extraocular muscle enlargement and persistent left frontal hematoma but no evidence of cavernous sinus or other venous thrombosis (Fig 3). Vision in the left eye was no light perception, and the left optic nerve was pale. The retinal vessels remained markedly attenuated, and diffuse retinal pigmentary disturbance was evident. Fluorescein angiography showed total
Figure 3. Case 2. Five days after surgery, coronal Tl-weighted magnetic resonance imaging shows enlargement of the extraocular muscles (small arrows) and a left frontal hematoma (large arrow).
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retinal and choroidal nonperfusion, and electroretinography waveforms were nonrecordable. Three weeks later, vision in the left eye remained no light perception with a 4+ relative afferent pupillary defect. The proptosis and chemosis gradually resolved, but the ophthalmoplegia and fundus abnormalities persisted, except for minimal recovery of upgaze. Case 3. A previously healthy 29-year-old woman had sudden headache, vomiting, and neck pain. Lumbar puncture and CT confirmed subarachnoid hemorrhage, and cerebral angiography showed a left anterior communicating artery aneurysm. The aneurysm was clipped via a left frontotemporal craniotomy. Four hours later, the patient's left pupil was noted to be nonreactive to light. Three days later, visual acuity was 20/20 in the right eye and no light perception in the left. The left pupil was 1 mm larger than the right and did not react to direct light (but did have a minimal consensual reaction). There was a marked left relative afferent pupillary defect. She had moderate left periorbital edema, chemosis, proptosis, and ptosis. Adduction, depression, and elevation were moderately diminished, and no abduction was present on the left. Left upper facial and corneal sensation were absent. Anterior segments were normal. Intraocular pressures were 16 mmHg in the right eye and 17 mmHg in the left. Left retinal edema and a cherry-red spot were evident, though the retinal vessels appeared normal in both eyes. Magnetic resonance imaging showed left proptosis but symmetric cavernous sinuses and no orbital hemorrhage. Three months after surgery, the patient remained blind in the left eye. The left afferent pupillary defect persisted, but the consensual pupillary response had normalized. Her left facial anesthesia, ptosis, proptosis, and ophthalmoplegia had completely resolved. The left optic disc was pale, and the retinal vessels were markedly attenuated. Case 4. A 55-year-old man with hypertension who was acutely comatose had subarachnoid hemorrhage on CT. His angiogram showed a right anterior communicating artery aneurysm which was clipped using a right frontotemporal approach. Three hours later, an unreactive right pupil and right ptosis were recorded. Two days later, vision was hand motions in the right eye and 20/50 in the left. The right pupil was minimally reactive to direct light with a marked relative afferent pupillary defect. There was a minimal right consensual pupillary response. Striking right proptosis, chemosis, and complete ptosis were present, and right upper facial and corneal sensation were diminished. Right eye ductions were absent. Intraocular pressures were 17 mmHg in the right eye and 18 mmHg in the left. The right retina was edematous, and there were scattered posterior pole blot hemorrhages. No cherry-red spot was evident, and the retinal vessels were normal. New findings on CT included a small right posterior frontal infarction and right orbital soft tissue swelling with proptosis. No orbital hemorrhage or cavernous sinus abnormalities were present. One month later, visual acuity was no light perception in the right eye and 20/20 in the left. The right afferent pupillary defect persisted, but the consensual response had normalized. His ptosis, chemosis, proptosis, and facial anesthesia had resolved, and motility had improved in the right eye. There was marked right retinal vascular attenuation, a pale optic disc, and diffuse pigmentary retinopathy. Six months later, ductions had normalized, but results of the examination otherwise were unchanged. Case 5. A 56-year-old woman with hypertension was found to have ophthalmoplegia due to thyroid orbitopathy and ocular myasthenia gravis. An incidental aneurysm of the right middle cerebral artery trifurcation was identified by magnetic resonance imaging, and she underwent elective aneurysm clipping via a right frontotemporal craniotomy.
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Upon arrival in the recovery room, the patient had right ptosis, proptosis, and ophthalmoplegia. Three hours later, she was still drowsy but visual acuity was no light perception in the right eye and 20/400 in the left. The right pupil did not react to light and there was no consensual response. A 4+ right relative afferent pupillary defect was present. There was complete right ptosis and ophthalmoplegia, marked chemosis, and 5 mm of right proptosis. Right upper facial and corneal sensation were absent. Intraocular pressures were 28 mmHg in the right eye and 13 mmHg in the left. Results of funduscopy showed retinal edema, arteriolar attenuation, and a cherry-red spot in the right eye. The lOP was treated with ocular massage and acetazolamide, timoptic, and paracentesis. Her CT scan showed a small right frontal infarction and right orbital soft tissue swelling with proptosis. Three weeks later, the right retinal edema had resolved but visual acuity was no light perception in the right eye and 20/25 in the left. The vertical ductions of the right eye had improved slightly. Three months later, visual acuity was unchanged, and the right afferent pupillary defect persisted. The external appearance and eye movements had returned to preoperative baseline. The right optic disc was pale, and the retinal vessels were attenuated. Case 6. A 74-year-old woman had acute headache, nausea, vomiting, and mental status changes 1 week before admission. A CT scan demonstrated an enhancing mass in the interpeduncular fossa, and the cerebrospinal fluid confirmed subarachnoid hemorrhage. Angiography showed a large basilar apex aneurysm and absence of the right posterior communicating artery. She underwent left frontotemporal craniotomy complicated by a small amount of intraoperative bleeding. On arrival to the intensive care unit after surgery, the patient was comatose. Both pupils were 5 mm and nonreactive. Within minutes, massive right-sided proptosis developed with subconjunctival hemorrhage. The right globe and orbit were rock hard by palpation; the cornea was clear and the anterior chamber was of moderate depth. The right pupil was 5 mm and nonreactive to direct or consensual light. There was total ophthalmoplegia and lagophthalmos of the right eye. Results of funduscopic examination showed a pale optic nerve and retinal artery nonperfusion in the right eye. The left pupil was 5 mm and nonreactive. Except for slight sparing of abduction, left eye ductions were absent. The left fundus showed only atherosclerotic changes. Intravenous acetazolamide and topical apraclonidine were administered as a right lateral canthotomy and cantholysis were performed. The right eye and orbit immediately softened, and the retina reperfused. Ten minutes after the above interventional measures, lOPs were 5 mmHg in the right eye and 8 mmHg in the left. Emergency CT of the head and orbit showed tenting of the posterior orbital wall on the right, with some stretching of the right optic nerve. There was preseptal soft tissue density, but no evidence of retrobulbar blood, optic nerve sheath hematoma, orbital mass, or enlarged extraocular muscles. Postoperative changes, including a small pneumocephalus, a thin collection of extra-axial fluid about the right frontal convexity, and mild right frontal edema with slight right-to-left shift, were seen. In addition, old right middle cerebral and right posterior cerebral artery infarctions were noted. No intraparenchymal blood was seen. The patient never regained consciousness after surgery. The right proptosis quickly resolved, though the ophthalmoplegia remained. The right fundus showed perfusion of the arteries and veins, though they were markedly attenuated. The right optic disc was pale and slightly swollen, with a small amount of subretinal fluid at the posterior pole. One week later, the disc edema
Zimmerman et al · Orbital Infarction Syndrome was resolving, and early retinal pigment epithelial abnormalities were evident. A CT showed no recurrent subarachnoid blood, though new bilateral thalamic infarctions were seen. Further diagnostic procedures and treatment were deferred at the family's request. Three weeks after surgery, her right fundus was unchanged. The right pupil was nonreactive to direct or consensual light. The left pupil was sluggishly reactive, and there was a 4+ right relative afferent pupillary defect. Extraocular movements were absent in both eyes. The patient died after transfer to an extended care facility, and permission for postmortem examination was denied.
Discussion The ophthalmic artery originates from the internal carotid artery and has numerous ocular and orbital branches, including the central retinal and ciliary arteries. Visual loss after orbital infarction results from retinal infarction (due to hypoperfusion of the central retinal artery) and from anterior ischemic optic neuropathy and choroidal ischemia (both due to compromise of the posterior ciliary arteries). Ophthalmoplegia results from impaired blood supply to the extraocular muscles or ocular motor nerves, and anterior segment ischemia from hypoperfusion of the long ciliary arteries. Because of the rich collateral circulation between the branches of the external carotid and ophthalmic arteries, ophthalmic artery occlusion alone does not cause this syndrome. However, if collateral blood flow is compromised by other factors, orbital infarction may develop. The clinical features of these patients are remarkably similar. All but one patient had otherwise uncomplicated surgery. Four patients had an anterior communicating aneurysm and one patient each had a basilar and middle cerebral aneurysm, but a frontotemporal approach was used in all six patients. Five of the six had subarachnoid hemorrhage, and one patient had elective surgery for an asymptomatic aneurysm. In all patients, unilateral proptosis, ophthalmoplegia, and blindness developed ipsilateral to the craniotomy immediately after surgery. Three patients had transient numbness in the cutaneous distribution of the ophthalmic nerve and ipsilateral corneal anesthesia. Retinal edema in the perioperative period was followed within weeks by retinal artery attenuation, pigmentary retinopathy, and optic disc pallor. Most patients recovered some ocular motility but all remained blind in the affected eye. Visual acuity could never be evaluated subjectively in case 6, but the presence of a 4+ relative afferent pupillary defect on indirect testing suggested no light perception. Initial and follow-up funduscopic examinations of all six patients were consistent with retinal and choroidal infarction. Limitation of motility with proptosis may be due to mechanical restriction, ischemia of the extraocular muscles and their nerve supply, or a combination of both. In our patients, some limitation of motility persisted after forced ductions became negative, suggesting a residual ischemic deficit. Ocular motility recovered or improved in five patients. In case 6, the presence of a third nerve
paresis on the contralateral side and an aneurysm in the interpeduncular fossa suggested the possibility of an oculomotor nuclear and/or fascicular lesion that could not be distinguished from that due to orbital infarction on clinical examination alone. Chronic anterior segment ischemia did not develop in any of the patients. Ophthalmic artery occlusion is characterized by severe visual loss, frequently to no light perception. Acutely, there is diffuse opacification of the retina due to edema. The retinal arteries may be attenuated, and there is variable absence of a cherry-red macula. Fluorescein angiography demonstrates retinal and choroidal nonperfusion and the electroretinogram is nonrecordable. Late fundus findings include diffuse pigmentary retinopathy, attenuated retinal vessels and optic atrophy. In contrast, patients with central retinal artery occlusion alone usually have counting fingers vision, and fluorescein angiography demonstrates choroidal filling due to sparing of the ciliary arteries. Preservation of the choroidal circulation is evident by the normal color of the choroid underlying the macula (the cherry-red spot), surrounded by pale edematous retina. Electroretinography shows extinction of the A-wave with preservation of the B-wave. 4 Ophthalmic rather than central retinal artery hypoperfusion was supported by typical fluorescein angiograms and electroretinograms in cases 1 and 2 and by typical fundus abnormalities in all patients. Hollenhorst et al 5 reported eight patients who were blind immediately after neurosurgical procedures. All patients had retinal ischemia, and five patients had proptosis, orbital congestion, and ophthalmoplegia. Five patients with proptosis remained blind or had hand motions vision. The authors postulated that increased orbital pressure from the direct contact of the affected eye by the face rest collapsed the orbital veins and arteries. This caused congestion and proptosis and lowered the ocular perfusion pressure with resulting ocular ischemia. Reduced blood pressure may have compounded the hypoperfusion in some patients. The authors produced similar findings of retinal and choroidal ischemia by exerting pressure on the globes of rhesus monkeys while inducing hypovolemia and hypotension. Visual loss is a rare complication of surgery of many specialties; procedures requiring general anesthesia and cardiopulmonary bypass, or those in which hypovolemia, hypotension, or hypothermia occur, are particularly at risk. 5- 11 Direct pressure on the globe due to improper positioning of the patient may be responsible for postoperative visual loss in some patients. 5 •6 •12•13 Jayam et al 14 describe a patient with irreversible unilateral ischemic retinopathy and peroneal neuropathy, after a period of deep, alcohol-induced stupor. The patient lay face down on his left side for 6 hours, awakening with blindness in his left eye, proptosis, ophthalmoplegia, and retinal edema. The electroretinogram was nonrecordable. This case of "Saturday night retinopathy" shared many similarities to the postoperative patients; the mechanism was thought to be increased orbital pressure due to the prolonged dependent position of the patient, causing pressure on the globe and compromising the retinal and ciliary circulation.
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The frontotemporal or "pterional" craniotomy exposure requires a myocutaneous flap to be retracted anteriorly and inferiorly near the orbit. Because the flap is retracted across the zygomatic arch, it is unlikely to directly contact the eyelid or globe; however, in some circumstances this bulky flap could indirectly exert pressure on the globe, especially in individuals with "shallow" orbits or significant orbital congestion. No additional cases have occurred in one institution after routine use of a protective aluminum eye shield. Admittedly, the effectiveness of this device in this rare disorder is difficult to prove. Hayreh and Edwards 15 demonstrated in monkeys that ophthalmic artery pressure is compromised when cerebrospinal fluid pressure exceeded 35 em H 20. Orbital venous pressure was directly related to cerebrospinal fluid pressure, and a sudden fall in the cerebrospinal fluid pressure resulted in a significant decrease in the ophthalmic artery perfusion pressure. Cases 1 to 4 had ruptured anterior communicating artery aneurysms, with grade III or higher subarachnoid hemorrhage and frontal edema. In cases 4 and 5, new frontal infarctions developed and case 6 had new bithalamic infarctions in the early postoperative period. In our patients, subarachnoid hemorrhage and/ or cerebral infarction may have increased the intracranial hypertension, increasing the orbital pressure and lowering ophthalmic artery perfusion. Abrupt reduction of the intracranial pressure or possibly impaired vascular autoregulatory function (common in subarachnoid hemorrhage) also may have compromised ophthalmic artery perfusion. High lOP may compromise retinal artery and choroidal perfusion. Cases 2 and 6 had markedly elevated orbital pressure and lOPs with no perfusion of the retinal vessels; emergency measures to lower the lOP promptly restored retinal perfusion, though not before irreversible posterior ocular ischemia occurred. Case 5 had moderately elevated lOP, but no such elevation was observed in the remaining patients, despite significant exophthalmos. Increased lOP may result from direct pressure applied to the eyelids or globe, or from increased orbital pressure. It is likely that some transient increases in lOP go unnoticed, especially in patients who are critically ill in the perioperative period. The cause of orbital infarction syndrome in our patients is probably multifactorial. We believe that ophthalmic artery perfusion pressure was lowered due to the combined effects of orbital venous outflow obstruction with increased intraocular and orbital pressure. Any conditions that might aggravate these factors, such as increased intracranial pressure, external pressure on the globe, or decreased ophthalmic artery perfusion pressure by any mechanism might increase the risk for orbital infarction. Although it is unlikely that any one of these factors will result in the complete clinical picture, we speculate that these risk factors may be cumulative. Visual loss due to ophthalmic artery occlusion often is profound and irreversible, and thus every precaution should be taken to minimize known risk factors. Increased intracranial pressure should be controlled. Systemic blood
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pressure should not be precipitously lowered, and hypotension and hypovolemia should be avoided. The patient should be positioned carefully, and surgical drapes, positioning apparatus, and retracted flaps should be placed so that no pressure is exerted on the globe. Patients undergoing procedures in the prone position may be at particular risk and may benefit from an aluminum eye shield. Orbital venous outflow pathways should be preserved, and cautery near the superior orbital fissure and cavernous sinus minimized. Significant proptosis and elevated lOP should be managed aggressively. Retrobulbar or optic nerve sheath hematoma should be identified promptly, because some patients may benefit from immediate surgery. Despite aggressive treatment, prognosis for significant visual recovery after orbital infarction is poor.
References I. Borruat F-X, Bogousslavsky J, Uffer S, et al. Orbital infarction syndrome. Ophthalmology 1993; 100:562-8. 2. Bogousslavsky J, Pedrazzi PL, Borruat F-X, Regli F. Isolated complete orbital infarction: a common carotid artery occlusion syndrome. Eur Neurol 1991 ;31 :72-6. 3. Vergez A. Syndrome oculaire rare au cours d'une thrombose carotidienne spontanee (thrombose de l'artere ophthalmique). Ann Ocul 1959;192:376-84. 4. Brown GC, Magargal LE, Sergott R. Acute obstruction of the retinal and choroidal circulations. Ophthalmology 1986;93: 1373-82. 5. Hollenhorst RW, Svien HJ, Benoit CF. Unilateral blindness occurring during anesthesia for neurosurgical operations. Arch Ophthalmol 1954;52:819-30. 6. Givner I, Jaffe N. Occlusion of the central retinal artery following anesthesia. Arch Ophthalmol 1950;43:197-201. 7. Johnson MW, Kincaid MC, Trobe JD. Bilateral retrobulbar optic nerve infarctions after blood loss and hypotension. A clinicopathologic case study. Ophthalmology 1987;94:157784. 8. Chisholm lA. Optic neuropathy of recurrent blood loss. Br J Ophthalmol 1969;53:289-95. 9. Cove DH, Seddon M, Fletcher RF, Dukes DC. Blindness after treatment for malignant hypertension. Br Med J 1979;2:245-6. 10. Larkin DFP, Connolly P, Magner JB, et al. Intraocular pressure during cardiopulmonary bypass. Br J Ophthalmol 1987;71: 177-80. II. Sweeney PJ, Breuer AC, Selhorst JB, et al. Ischemic optic neuropathy: a complication of cardiopulmonary bypass surgery. Neurology 1982;32:560-2. 12. Wolfe SW, Lospinuso MF, Burke SW. Unilateral blindness as a complication of patient positioning for spinal surgery. A case report. Spine 1992;17:600-5. 13. Slocum HC, O'Neal KC, Allen CR. Neurovascular complications from malposition on the operating table. Surg Glynecol Obstet 1948;86:729-34. 14. Jayam AV, Hass WK, Carr RE, Kumar AJ. Saturday night retinopathy. J Neurol Sci 1974;22:413-18. 15. Hayreh SS, Edwards J. Ophthalmic arterial and venous pressures. Effects of acute intracranial hypertension. Br J Ophthalmol 1971 ;55:649-63.