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Show Carotid End arte recto my for Ophthalmic Manifestations: Is It Ever Indicated? Robyn J. Wolintz, MD Abstract: Four ophthalmic manifestations make up a sub- In 2001, Benavente et al ( 8) finally compared the stantial proportion of the indications for carotid endarter- NASCET stroke rate among patients who presented with ectomy ( CE). They include transient monocular visual loss TMVL to that of patients with 50%- 99% carotid stenosis ( TMVL), ocular ischemic syndrome ( OIS), retinal artery who presented with hemispheric TIA ( HTIA). TMVL was occlusion ( RAO), and asymptomatic Hollenhorst plaque. the presenting symptom in 397 patients; HTIA was the Critical review of the literature shows that the evidence to presenting symptom in 829 patients. The 3- year risk of ipsi-support the efficacy of CE in these four settings is tenuous. lateral stroke among medically treated patients with TMVL , TTiT y> f . f i i *> nnr *> r *> nn , n , > was 10%, whereas in patients with HTIA, it was 20%. ( J Neuro- Ophthalmol 2005: 25: 299- 302) _ x ' „ , , , , , •'•, ™ „„ Thus, the non- surgically treated patients with TMVL were at substantially lower risk of hemispheric stroke than were Carotid endarterectomy ( CE) is a widely performed those with HTIA. operation in patients with critical stenosis of the cer- Among the patients with TMVL, the degree of vical carotid artery ( 1- 4). The evidence to support the stenosis was, surprisingly, not a risk factor for stroke. Stroke efficacy of CE in prevention of stroke is based on several occurred in 10.1% of patients with 70%- 79% stenosis, in large collaborative trials ( 5,6). These trials have included 9.8% of those with 50%- 69% stenosis, and in 9.1% of those patients whose manifestations are entirely ophthalmic, and with total occlusion of the internal carotid artery. However, it is estimated that these manifestations are currently the there were six risk factors for stroke in the TMVL group: basis for up to 25% of transient ischemic attacks ( 7). A i) m a i e ; 2) age of 75 years or older, 3) history of HTIA or 2001 report ( 8) released evidence from one of the major CE stroke, 4) history of intermittent claudication, 5) ipsilateral in-clinical trials that suggests that CE is not effective in ternal carotid artery stenosis of80%- 94%, and 6) absence of preventing stroke in most patients with transient monocular collateral vessels on angiography. Among medically treated visual loss ( TMVL). The evidence for the efficacy of CE in patients with one of the above risk factors, the 3- year risk the three other ophthalmic manifestations ( ocular ischemic of ipsilateral stroke was 1.8% ( low- risk group). For those pa-syndrome [ OIS], retinal artery occlusion [ RAO], and asymp- tients with two risk factors, it increased to 12.3% ( moderate-tomatic Hollenhorst plaque) is also weak ( Table 1). risk group), and among those with three or more risk factors, it reached 24.2% ( high- risk group). TRANSIENT MONOCULAR VISUAL LOSS Amon& T M V L Pa t i e n t s w h o underwent CE, the The North American Symptomatic Carotid Endarter- absolute reduction in the 3- year stroke risk was 2.2% in the ectomy trial ( NASCET) ( 5) and the European Carotid low- risk group, 4.9% in the moderate- risk group, and 14.3% Surgery Trial ( ECST) ( 6) showed that CE was beneficial in * t h e high- risk group. Thus, in the low- risk group, which reducing the risk of stroke in patients who had 70%- 99% comprised 80% of the TMVL patients, CE was harmful. In stenosis of the internal carotid artery noted within 180 days & e moderate- risk group, CE was only mildly beneficial; in after hemispheric or monocular transient ischemic attack more t h a n a 3" year period, 20 patients would have had to ( TIA) or minor hemispheric stroke. In the original NASCET undergo CE to prevent one stroke. In the high- risk group, CE and ECST publications, the efficacy of CE applied to the was m o r e beneficial; even so, seven patients would have had patient group as a whole; the data for the 496 patients who to undergo CE to prevent one stroke, had isolated monocular TIA ( or TMVL) were not reported. Why sh° uld the stroke risk in patients with TMVL be so much lower than it is in patients with HTIA? One hypothesis is that it takes smaller emboli to impair vision Department of Neurology, Maimonides Medical Center, Brooklyn, thaQ Q t h e r b r a j n f u n c t i o n s > a n d s u c h s m a l l e m b o l i m i g h t . . . ' . . D . T w ,• . , m . • , , be unlikely to cause future hemispheric stroke. A second Address correspondence to Robyn J. Wolintz, MD, Assistant J r Attending, Co- Director of the Multiple Sclerosis Care Center, Maimon- hypothesis is that TMVL is Caused by a mechanism Other ides Medical Center, Brooklyn, NY 11219; E- mail: prweint@ aol. com than embolism from the carotid artery ( 9). Regardless of the explanation, the only reasonable interpretation of the recent arteries ipsilateral to the ischemic eyes were treated with NASCET data ( 8) is that CE should not be performed in CE. Only 7% of the eyes had improved visual acuity one patients with fewer than two of the above- mentioned risk year after surgery; 60% of the eyes actually had worse factors and is of questionable benefit in those who have visual acuity at one year. fewer than three risk factors. With so little published documentation, it seems that the verdict is still out on whether CE is beneficial in improving visual outcome and reducing stroke risk in patients OCULAR ISCHEMIC SYNDROME who Pr e s e n t w i t n s iSn s consistent with the OIS. OIS is characterized by rubeosis iridis, venous stasis retinopathy, narrowed retinal arteries, mid- peripheral retinal hemorrhages, posterior segment neovascularization, and RETINAL ARTERY OCCLUSION increased intraocular pressure ( 10). The association of extra- RAO is often presumed to result from extracranial cranial carotid artery occlusive disease with OIS has been carotid artery embolism, but other mechanisms may be caus-well described ( 11). It is estimated that 5% of patients with ative, including orbital trauma, coagulopathies, migraine, use marked carotid artery stenosis present with OIS ( 12). Is of oral contraceptives, and carotid angiography. In two large their visual prognosis and risk of stroke affected by CE? series of CE performed in patients with RAO ( 15,16), a Most reports involve single cases with poor docu- relatively small proportion of patients had hemodynamically mentation and short follow- up. There are only two published significant carotid stenosis. For example, among 34 patients series. Rubin et al ( 13) reported 18 patients who underwent with idiopathic RAO reported by Merchut et al ( 15), only CE for OIS manifested by rubeosis iridis, venous stasis four had ipsilateral internal carotid artery stenosis of retinopathy, and increased intraocular pressure. In that series, 80% or more. Ipsilateral carotid artery stenosis of 60% or 11 patients complained of intermittent or persistent loss of less was found in five ( 15%) patients, and entirely normal vision, 5 described pain in or around the eye, and 2 were studies were found in five ( 15%) patients. Appen et al ( 16) asymptomatic. All patients had visual acuity measurements, reported occlusive disease of the ipsilateral internal carotid slit lamp examination, ophthalmoscopy, ophthalmodyna- artery in 11% of 44 patients with central RAO. mometry, and photostress testing. Abnormalities on oph- There is only one adequately documented series that thalmoscopy were noted in 15 eyes. After CE, 14 patients describes the results of CE in RAO patients ( 17). In this described improvement in vision and in periocular pain. nonrandomized study of 23 patients, 16 underwent CE. Visual acuity improved in 6 patients and was unchanged in None of the CE patients had a subsequent neurologic event 11 patients. Ophthalmoscopic examination after surgery re- during an average follow- up period of 18.7 months. Among vealed improvement in ischemic findings in 14 eyes and total these 16 operated patients, two had complete occlusion of resolution in 4 eyes. the internal carotid artery, one had more than 90% stenosis, Sivalingam ( 14) found no benefit of CE in 52 patients and 13 had less than 50% stenosis. Three of the seven pa-who presented with OIS. In this group, 28% of the carotid tients ( 43%) in the non- surgical group had a stroke during the mean follow- up period of 28.3 months. This difference 11.8% in the delayed CE group. These results included a was statistically significant, so the authors recommended 3% perioperative morbidity and mortality risk. The prob- CE in RAO patients who are found to have carotid artery ability of a stroke was not affected by the amount of carotid stenosis, without specifying the degree of stenosis that stenosis; the 5- year stroke risk was 2.1% in CE patients would warrant CE. with less than 80% stenosis and 3.2% in CE patients with more than 80% stenosis. Thus, the results in ACST remarkably replicated those of the earlier ACAS trial. Although ASYMPTOMATIC HOLLENHORST PLAQUE CE seemed to reduce the risk of stroke, the benefit was Hollenhorst plaques, or intraluminal retinal choles- minimal, terol/ fibrin deposits, are commonly found on routine ophthal- Schwarcz et al ( 21) evaluated the role of CE in 64 pa-mologic examinations of visually asymptomatic patients. tients with HoUenhorst plaques, most of whom were asymp- Is CE beneficial in preventing stroke in patients who have tomatic. Among 28 patients in whom CE was performed on asymptomatic Hollenhorst plaques? the side of the Hollenhorst plaque, 24 were visually asymp- This issue may be approached first by considering the tomatic. No CE was performed on 39 patients, 37 of whom indications for CE in asymptomatic carotid artery stenosis were visually asymptomatic. Patients were observed for 50 without Hollenhorst plaques. The Asymptomatic Carotid months with periodic ophthalmologic, neurologic, and non- Atherosclerosis Study ( ACAS) ( 18) enrolled 1,662 patients invasive vascular examinations. The mean annual rate of with asymptomatic carotid artery stenosis of 60% or more stroke ipsilateral to asymptomatic Hollenhorst plaques was discovered during evaluation for peripheral vascular surgery, 2.4% in patients who underwent CE and 3.0% in those who contralateral CE, or a carotid bruit. Patients were random- did not undergo CE, a difference that was not statistically ized to conventional medical management ( 325 mg regular significant. aspirin) or CE. The estimated 5- year ipsilateral stroke rate The authors concluded that in patients with asymp-was 11% in the medically managed group and 5.1% in the tomatic Hollenhorst plaques, CE should not be recom- CE group. The estimated 30- day morbidity and mortality of mended unless the patient develops hemispheric symptoms the ACAS patients, including complications of angiogra- or signs referable to the appropriate carotid circulation and, phy, was 2.7%. Therefore, although the study concluded even then, medical management is probably better, that CE decreases the risk of stroke in asymptomatic patients with more than 60% stenosis of the internal carotid artery, the benefit disappears if the perioperative morbidity and mortality rate exceeds 3% ( 18). 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