A 71-year-old man comes to the emergency department due to sudden-onset vision loss in his left eye for one hour. He has a history of coronary artery disease, hypertension, and type 2 diabetes mellitus. Blood pressure is 145/80 mm Hg and pulse is 72/min. On examination, the patient can see only hand motions through the left eye. Funduscopic evaluation of the eye shows a cherry-red spot in the macula with surrounding retinal whitening. Cranial nerve examination is otherwise unremarkable. There is a left-sided neck bruit on cardiovascular examination. Which of the following is the most likely path of the embolus causing this patient's symptoms?

Question

A 71-year-old man comes to the emergency department due to sudden-onset vision loss in his left eye for one hour.  He has a history of coronary artery disease, hypertension, and type 2 diabetes mellitus.  Blood pressure is 145/80 mm Hg and pulse is 72/min.  On examination, the patient can see only hand motions through the left eye.  Funduscopic evaluation of the eye shows a cherry-red spot in the macula with surrounding retinal whitening.  Cranial nerve examination is otherwise unremarkable.  There is a left-sided neck bruit on cardiovascular examination.  Which of the following is the most likely path of the embolus causing this patient's symptoms?

Quizplus · Accepted Answer

11ec160b_3566_4a37_9249_99e01d02f105_MD0001_00 Retinal artery occlusion (RAO) is an important cause of acute, painless, monocular vision loss. Thromboembolic complications of atherosclerosis in the internal carotid are the most common cause of RAO. The retinal artery is one of the first branches of the ophthalmic artery, which receives its supply from the internal carotid (Choice B). The retinal artery then travels within the retinal nerve to supply the inner retina and the surface of the optic nerve. (Choices A and C) There are a number of anastomoses between branches of the ophthalmic artery and branches of the external carotid, including the facial artery and temporal artery, but neither branch anastomoses with the retinal artery or supplies the retina. (Choice D) The anterior cerebral artery is a branch off the circle of Willis that supplies blood to the midline portions of the frontal and superior medial parietal lobes. Its occlusion can lead to loss of strength and sensation in the contralateral lower extremity, incontinence, and transcortical motor aphasia. Educational objective: Retinal artery occlusion is a cause of acute, painless, monocular vision loss. It is usually caused by thromboembolic complications of atherosclerosis traveling from the internal carotid artery and through the ophthalmic artery. __________ References: Orbital vascular anatomy. (http://www.ncbi.nlm.nih.gov/pubmed/17019411) Ocular ischemic syndrome - a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/22847215)

A 71-Year-Old Man Comes to the Emergency Department Due to Sudden-Onset