Hollenhorst Plaques These May Be Just the Tip of the Iceberg

MEDICAL RETINA FEATURE STORY

Hollenhorst Plaques These may be just the tip of the iceberg.

By Charles C. Wykoff, MD, PhD; and Daniel E. Croft, BA

“The good physician treats the disease; the great physician treats the patient who has the disease.” –William Osler, MD, one of the Founding Many of our patients are Professors of Johns Hopkins Hospital affected by retinal pathologies that are merely a manifestation s retina specialists, we have the privilege of car- ing for patients with blinding diseases every day. of a systemic disease. Many of these patients have isolated retinal pathologies such as age-related macular degen- Aeration or rhegmatogenous retinal detachment. Many of his left eye (Figure 1) with normal filling in his right eye. our patients, however, are affected by retinal pathologies Following a discussion of management options, the that are merely a manifestation of a systemic disease, patient chose to be evaluated immediately in a local such as diabetic retinopathy. Indeed, because of the high emergency room. There, the patient was found to have metabolic demand of the retina and because the retinal >90% proximal, left internal carotid artery narrowing and choroidal circulations receive proportionally higher (Figure 2). The patient underwent urgent vascular sur- blood flow volumes per unit area than many other tis- gery with left internal carotid endarterectomy (CEA) and sues, these vascular beds are often affected by systemic implantation of a xenograft patch. The patient recovered diseases earlier than other parts of the body. rapidly and has remained asymptomatic. Four months following CEA, FA revealed significantly normalized vas- Case Presentation and Results cular filling of his left retinal circulation (Figure 3). An asymptomatic 55-year-old man with 20/20 visual acuity in both eyes was referred after presenting with Discussion a Hollenhorst plaque in the left eye during a routine Hollenhorst plaques were first described in 1961 by ophthalmic examination. Fluorescein angiography Robert Hollenhorst, MD, who aptly inferred their intraar- (FA) revealed significantly delayed vascular filling in terial location as indicative of embolic disease, classically

A B

Figure 1. Fundus photograph left eye: Hollenhorst plaque (arrow) involving the inferior major retinal arteriole within the optic nerve head (A). Fluorescein angiograph showing delayed vascular filling of the retinal circulation (1 minute 51 seconds; B).

74 RETINA Today November/December 2013 MEDICAL RETINA FEATURE STORY

A B C D

Figure 2. CT angiogram: Right common, internal, and external carotid circulations are normal (A). Proximal left internal carotid artery has >90% lumen narrowing (arrow; B). Carotid ultrasound: Right common, internal, and external carotid arteries with normal vascular flow (C). Left internal carotid artery with significantly reduced vascular flow (D).

A B C

Figure 3. External photograph showing scar from carotid endarterectomy (A). Fundus photograph left eye: Stable Hollenhorst plaque (arrow; B). Fluorescein angiograph showing improved vascular filling of the retinal circulation with complete filling at 52 seconds (C).

related to carotid arterial disease.1,2 bral vascular accident (CVA). For example, in the North Does the presence of a Hollenhorst plaque, whether American Symptomatic Carotid Endarterectomy Trial symptomatic or asymptomatic, necessitate emergent (NASCET), patients with transient monocular visual loss evaluation for an embolic source? Certainly the answer (TMVL), transient ischemic attack (TIA), or nondisabling depends on the specific circumstances of each patient. stroke and severe carotid stenosis (70% to 99%) were In the case of a symptomatic Hollenhorst plaque, randomized to CEA or medical management; CEA led to urgent embolic evaluation including carotid ultrasound a 2-year ipsilateral stroke rate of 9% vs 26% for patients analysis is probably indicated, as approximately 25% may undergoing medical management alone (P = .001).4 have substantial carotid artery stenosis.3 In patients with Approximately 75% of Hollenhorst plaques seen in moderate to severe carotid artery stenosis, CEA can sub- ophthalmic practice are asymptomatic.3 Many studies stantially reduce the risk of subsequent hemispheric cere- have considered the relationship between asymptomatic

November/December 2013 RETINA Today 75 MEDICAL RETINA FEATURE STORY

plaques and the presence of significant carotid artery a Hollenhorst plaque may be but a marker for a more stenosis; significant ipsilateral carotid stenosis can be serious systemic situation. n identified in 5.6% to 9% of such patients.3,5,6 According to a meta-analysis of 3 randomized controlled trials involv- Charles C. Wykoff, MD, PhD, is a member ing 5223 patients with asymptomatic moderate to severe of the Retina Consultants of Houston and a stenosis, intervention with CEA may be indicated if the Clinical Assistant Professor of Ophthalmology perioperative risk is low, as risk of subsequent stroke or at Weill Cornell Medical College, Methodist mortality can be reduced substantially (relative risk = Hospital, Houston, TX. He is a member of the 0.69, favoring CEA).7 Retina Today Editorial Board. Dr. Wykoff states In the presence of a Hollenhorst plaque, one may con- that he has no financial interest in any products sider auscultation of the ipsilateral carotid artery with a mentioned in this article. He can be reached at stethoscope. The presence of a carotid bruit may signify [email protected]. a higher risk of significant carotid artery stenosis and may Daniel E. Croft, BA, is a senior research assis- help predict CVA, myocardial infarction, and death.3,8 tant with the Retina Consultants of Houston. Although some studies have identified value in prognos- 1. Hollenhorst RW. Ocular manifestations of insufficiency or thrombosis of the internal carotid artery. Trans Am tication, others have suggested that the results of carotid Ophthalmol Soc. 1958;56:474-506. artery auscultation have neither high specificity nor sen- 2. Hollenhorst RW. Significance of bright plaques in the retinal arterioles. Trans Am Ophthalmol Soc.1961;59:252-273. 9 3. Bakri SJ, Luqman A, Pathik B, et al. Is carotid ultrasound necessary in the clinical evaluation of the asymptomatic sitivity, particularly in asymptomatic patients. hollenhorst plaque? (An american ophthalmological society thesis). Trans Am Ophthalmol Soc. 2013;111:17-23. Evidence suggests that both symptomatic and 4. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325(7):445-453. asymptomatic Hollenhorst plaques may be markers 5. Bull DA, Fante RG, Hunter GC, et al. Correlation of ophthalmic findings with carotid artery stenosis. J Cardiovasc for significant carotid artery disease, and their presence Surg (Torino). 1992;33(4):401-406. 6. Wakefield MC, O’Donnell SD, Goff JM, Jr. Re-evaluation of carotid duplex for visual complaints: who really needs indicates risk factor analysis and carotid ultrasonog- to be studied? Ann Vasc Surg. 2003;17(6):635-640. raphy. If a patient chooses to defer evaluation until a 7. Chambers BR, Donnan GA. Carotid endarterectomy for asymptomatic carotid stenosis. Cochrane Database Syst Rev. 2005(4):CD001923. later time, one may consider documenting that urgent 8. Pickett CA, Jackson JL, Hemann BA, et al. Carotid bruits as a prognostic indicator of cardiovascular death and myocardial infarction: a meta-analysis. Lancet. 2008;371(9624):1587-1594. referral was offered. Just as the tip of an iceberg is only a 9. Cournot M, Boccalon H, Cambou JP, et al. Accuracy of the screening physical examination to identify subclinical small part of the whole underneath the ocean’s surface, atherosclerosis and peripheral arterial disease in asymptomatic subjects. J Vasc Surg. 2007;46(6):1215-1221.