Article, Ophthalmology

Sentinel central retinal artery occlusion: a forme fruste of idiopathic renal infarction

Case Report

Sentinel Central retinal artery occlusion: a forme fruste of idiopathic Renal infarction

Abstract

Central retinal artery occlusion is one of the most challenging practices and is not an infrequent presentation at the emergency department. We describe a 46-year-old man presenting with abrupt onset of amaurosis fugax secondary to sentinel central retinal artery occlusion followed by acute idiopathic renal infarction. This patient highlights that the preceding visual events could portend a devastating thromboembolic insult in the clinical setting. Early recognition with prompt treatment may preserve Organ function, avoid unnecessary management, and prevent debilitating complication.

A 46-year-old man presented to the emergency depart- ment with a sudden onset, painless blackout spell in the left eye, and Right flank pain radiating to the lower abdomen. In the past 2 weeks, he experienced several episodes of temporary Blurred vision in the left eye followed by spontaneous recovery within few minutes. He reported no illicit drug use, trauma, or medical history; and his family history was noncontributory. He was alert and his blood pressure was 146/80 mm Hg, pulse rate 82 beats per minute, respiratory rate 19 per minute, and body temperature 36.8?C. Upon ophthalmologic examination, there were light percep- tion of visual acuity, positive Afferent pupillary defect, and macular cherry-red spot with edematous retina on fundo- scopy, characteristic of central retinal artery occlusion (CRAO) (Fig. 1). Laboratory findings showed hemoglobin

14.1 g/dL, platelet count 235 x 109/L, and leukocyte count

8.2 x 109/L with predominance of neutrophils. Serum biochemistry revealed blood urea nitrogen 24 mg/dL, creatinine 1.8 mg/dL, C-reactive protein 6.2 mg/dL, lactate dehydrogenase 872 U/L, and normal electrolytes and liver function. Urinalysis revealed sterile, moderate hematuria coupled with apparent granular casts, indicating acute tubular necrosis. Contrast-enhanced computed tomography scan illustrated a well-demarcated wedge-shaped hypoatte- nuation of the right kidney, consistent with acute ischemic vascular infarction. The comprehensive workups for hyper- coagulation disorders, including infectious thromboembo- lism, hyperhomocysteinemia, deficiencies of antithrombin

III, protein C and S, antiphospholipid antibody syndrome, hematologic disorder, Paraneoplastic syndrome, and auto- immune disease, were all negative, supporting the diagnosis of idiopathic renal infarction. Although intra-arterial throm- bolytic therapy with urokinase (Fig. 2) followed by systemic anticoagulation treatment was carried out immediately, his visual acuity and renal function failed to recover completely. Central retinal artery occlusion frequently causes severe and irreversible Visual loss. An embolus from the carotid artery or the heart chambers is the most common culprit, whereby to reduce or even completely deprive blood perfusion to the retina. The characteristic feature is an acute, painless loss of vision in the range of counting fingers to light perception in 90% of patients; and cardinal signs include afferent pupillary defect, and pale and swollen optic nerve with splinter hemorrhages. The occurrence of cherry- red spot and mild or marked retinal edema associated with sudden painless visual loss is a hallmark of the disease. Generally, CRAO is usually associated with systemic hypertension, diabetes mellitus, and valvular heart disease [1]. Moreover, like cerebral infarction, CRAO is often found in older patients with underlying precipitating factors. However, it may jeopardize younger individuals, especially in those with migraine, trauma, congenital heart disease, and

various heriditary hypercoagulation states [2].

Acute renal infarction usually occurs in the sixth to eighth decade of life with a myriad of etiologies [3]. Its typical

Fig. 1 Fundus photograph of the left eye revealing the cherry red spot and retinal edema.

0735-6757/$ – see front matter (C) 2009

253.e2 Case Report

paracentesis, vasodilators, hemodilution, Hyperbaric oxygen, or surgical removal of the embolus has proven effective [8]. Anticoagulants should be reserved for the secondary prevention of cerebral or ocular infarction in those patients with underlying diseases requiring long-term anticoagulation therapy or selected Hypercoagulable states.

Our patient highlights that the preceding visual events may portend a devastating thromboembolic insult. If unrecognized, ensuing overwhelming compromise of renal function and permanent visual loss may occur. It should be addressed that, even with modern imaging modality, the heralding symptoms could be easily overlooked in General practice. Better outcomes only rely on heightened vigilance and early intervention.

Fig. 2 selective angiography of right renal artery showing thrombi within the middle interlobar branch of right renal artery with resultant territorial infarction.

manifestations include persistent steady, low back, abdom- inal or flank pain, accompanied by nausea, vomiting, and fever [4]. In contrast, idiopathic form of renal infarction, albeit rare, usually occurs in younger population and is a diagnosis of exclusion. It is still unclear whether the idiopathic nature represents a distinct disease entity or just reflects the tip of the iceberg for vasculopathy. Despite advances in the diagnostic armamentarium with which to unravel the conundrum of its idiopathic origin, the prognosis seems to improve little over the past years. The reasons for the resultant irreversible, relentless attrition of renal function can be attributed, at least in part, to delayed identification and lack of effective risk screening.

Optimal treatment of idiopathic renal infarction remains unknown. In comparison with the results of surgical management, anticoagulant and/or thrombolytic therapy provided favorable outcomes with good recovery of renal function [5]. Aside from initial renal function, completeness of Arterial occlusion, the size and site of clot, presence of collateral circulation, and the question of renal salvage would be expected to depend on time interval to intervention [6]. In patients with total parenchymal involvement secondary to bilateral emboli or to a unilateral main renal artery embolus in a solitary kidney, surgical embolectomy is recommended because of favorable kidney salvage and operative mortality rate [7]. Similarly, there is no consensus on treatment strategy of CRAO. Most ophthalmologists agree that attempting to dislodge a visible retinal embolus by ocular massage and nonaggressive decrease of Intraocular pressure by medications may be useful in some patients. However, there is no evidence supporting the use of anterior chamber

Ying-Jen Chen MD Department of Ophthalmology Tri-Service General Hospital National Defense Medical Center

Taipei 114, Taiwan

Wei-Liang Chen MD Wei-Chi Tsai MD

Department of Emergency Medicine Tri-Service General Hospital National Defense Medical Center

Taipei 114, Taiwan

Yu-Tzu Tsao MD

Department of Medicine Tri-Service General Hospital National Defense Medical Center

Taipei 114, Taiwan E-mail address: [email protected]

doi:10.1016/j.ajem.2008.06.027

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