An 82-year-old man with a history of atrial fibrillation presents to the emergency room complaining of sudden-onset, painless vision loss in his right eye starting 2 days ago. When it started, he felt like a “curtain was pulled down” over his right eye but wasn't able to seek care immediately because it was snowing outside and he didn't want to travel in inclement weather. A review of systems is significant for occasional palpitations and presyncope. The patient’s medications include aspirin and carvedilol. He reports that he is a smoker with a 50-pack-year history. The patient’s temperature is 99°F (37.2°C), blood pressure is 112/72 mmHg, pulse is 84/min, and respirations are 14/min with an oxygen saturation of 97% on room air. Physical exam reveals 20/800 vision in the right eye. A fundoscopic exam of the right eye is shown in Figure A. Physical and fundoscopic examinations of the left eye are unremarkable. Which of the following is the most appropriate next step in management?
Start retinal photocoagulation
Continue aspirin and start statin therapy
Administer tissue plasma activator
Start timolol drops
Continue aspirin and start statin therapy
This patient with a history of atrial fibrillation is presenting with acute-onset, painless, monocular vision loss and a fundoscopic exam positive for retinal whitening. This suggests a diagnosis of central retinal artery occlusion and management should focus on control of underlying risk factors given that he is 2 days out from the event.

Symptoms of central retinal artery occlusion (CRAO) include sudden, painless, complete, and normally unilateral vision loss. A fundoscopic exam can show pallor of the optic disc, diffuse ischemic whitening of the retina, cherry-red macula, retinal edema, and constricted/bloodless retinal arterioles. The center of the macula appears red because the photoreceptor layer at the fovea is perfused by the posterior choroidal vasculature rather than the central retinal artery. Treatment involves surgical decompression of the retinal anterior chamber, ideally within 1 hour of the occlusion. Tissue plasminogen activator should be administered if the patient presents within an acceptable time frame. If surgical intervention is not readily available, additional steps with minimal evidence to support their use include ocular massage (to dislodge the embolus) and either carbogen therapy or hyperbaric oxygen. Chronic management includes control of underlying risk factors with aspirin and statin therapy.

Dattilo et al. review the evidence regarding the treatment of central retinal artery occlusion. They discuss how treatments have not been particularly effective in the treatment of this disorder. They recommend engaging in secondary prevention of vascular events by controlling risk factors.

Figure/Illustration A is a fundoscopic photograph showing retinal pallor surrounding the superior temporal arcade (red circle). This finding is characteristically seen in central retinal artery occlusion.

Incorrect Answers:
Answer A: Administering ranibizumab is not appropriate because this medication is an anti-VEGF antibody, which can be used to treat wet age-related macular degeneration. Symptoms of wet age-related macular degeneration include acute visual distortion and loss of central vision that occurs over months. A fundoscopic exam would show neovascularization.

Answer B: Administration of tissue plasma activator has not been shown to be beneficial in central retinal artery occlusion if the event has occurred several days ago. This medication is used in patients who sustain an ischemic stroke within 4.5 hours of developing symptoms. A stroke in the posterior lobe can present with cortical hemianopsia.

Answer D: Retinal photocoagulation is used to treat diabetic retinopathy. In diabetic retinopathy, symptoms of painless vision loss present gradually. A retinal exam would show retinal hemorrhage and possibly neovascularization.

Answer E: Timolol is a beta-blocker used to treat glaucoma. Assessment of the optic disk would show an enlarged cup-to-disk ratio. Glaucoma can present with pain and pressure in the affected eye. Acute angle closure glaucoma would present with a rock-hard eye and may lead to permanent vision loss if not treated promptly.

Bullet Summary:
Chronic management of central retinal artery occlusion involves control of underlying risk factors with aspirin and statin therapy.