Central Retinal Artery Occlusion
The retina has become milky because of infarction. Tissue necrosis makes the tissue lose its normal transparency.
The red-orange color of the fovea appears in stark contrast to the surrounding milky retinal edema. Called a "cherry-red spot," it results from the fact that the fovea contains only the photoreceptor layer, which is spared because it is nourished by the choroidal circulation rather than the retinal circulation.
A cherry-red spot can also occur in lysosomal enzyme disorders in which lipid builds up in retinal ganglion cells. Good examples are , Mucolipidosis Type 1 and 2, Multiple Sulfatase Deficiency, and Niemann-Pick Type A.
Central retinal artery occlusion
There are two mechanisms: embolism and thrombosis. The relative prevalence of each mechanism is unknown.
Emboli may come from the ophthalmic or carotid artery, aortic arch, or heart. Local thrombosis is associated with any prothrombotic state, most commonly arteriosclerosis.
The blindness is profound and sudden, but painless because the retina has no sensory innervation.
What to do?Send the patient promptly to an ophthalmologist. Treatmentwhich may not be very effectiveis aimed at lowering pressure in the eye, in hopes of getting the clot to move farther out in the arterial tree. This is done by aspirating fluid out of the anterior chamber, applying finger pressure to squeeze aqueous out through normal exit pathways, or administering acetazolamide to reduce aqueous production.
Thrombolysis has not been proven effective.
The patient needs a full work-up for stroke.