Review Question - QID 104471

This patient is presenting with sudden monocular vision loss, atrial fibrillation, a cherry red spot on the macula, and a normal ocular ultrasound suggesting a diagnosis of central retinal artery occlusion (CRAO).

Central retinal artery occlusion presents acutely as a painless, monocular loss of vision. The retina will appear pale on fundoscopic exam with a cherry-red macula. This occurs because the loss of perfusion of the retina allows blood from the choroid to shine through. Risk factors can include a hypercoagulable state and atrial fibrillation. Treatment can involve digital massage of the globe and CO2 rebreathing, which function to dilate retinal vessels in an attempt to pass the clot into a distal segment of the vessel (though there is not concrete evidence to support this practice).

Figure A is an ECG demonstrating atrial fibrillation with an irregularly, irregular rhythm with no P waves. Figure B is an ultrasound of the eye that is unremarkable and does not demonstrate a free flap (thus, ruling out retinal detachment). Figure C is the fundoscopic finding of a cherry red macula.

Incorrect Answers:
Answer 2: Central retinal vein occlusion presents with the "blood and thunder" finding on fundoscopy in addition to vision loss.

Answer 3: Hemorrhagic stroke would present with focal neurological deficits that worsen as there is continued bleeding. It is unlikely this patient is having a stroke given his only neurological finding is monocular vision loss.

Answer 4: Ischemic stroke would present with focal neurological deficits that extend beyond just monocular vision loss. Though this diagnosis is possible, the fundoscopy findings and otherwise normal neurological exam suggest against this.

Answer 5: Retinal detachment would present with vision loss described as "a curtain coming down over the vision" with an ultrasound showing a free flap in the eye.

Bullet Summary:
Central retinal artery occlusion presents with a sudden monocular loss of vision.