Central Retinal Artery Occlusion
- Overview
- Cause
- Evaluation
- Treatment
The circulation to the retina enters the eye through the central retinal artery. When a patient develops a sudden occlusion of the central retinal artery, the vision suddenly and severely declines. Research has shown that retinal cells become irreversibly damaged after the vessel is occluded for more then 45 minutes.
Patients with a central retinal artery occlusion can usually only see shapes and movevment. Over time, 5% to 10% of patients recover some useful vision. The majority of patients recover some side vision, but do not regain central vision.
Most central retinal artery occlusions are embolic. A cholesterol, calcium, or platelet emboli breaks free from the carotid artery or from the heart and travels to the eye where it blocks the artery. A central retinal artery occlusion is considered a stroke.
In an elderly patient, giant cell arteritis can cause a central retinal artery occlusion through inflammation of the artery. In patients who have malaise, headache, and jaw pain, it may be appropriate to order special testing looking for possible giant cell arteritis.
The eye can be evaluated with special testing. Usually fundus photograph (see right panel) and fluorescein angiography (see below). Normally the retinal vessels completely fill (turn white) within four seconds of the fluorescein dye entering the eye. In the below animation the retinal vessels take over 2 minutes to fill with dye. The white background which occurs in the first 20 seconds is from fluorescein dye filling the choroidal vessels which are behind the retina.
Systemic evaluation for stoke risk is important looking for possible sources for an embolism. Usually carotid and cardiac ultrasound are obtained. Sometimes other testing is necessary.
