Central
Retinal Artery OcclusionIntroduction: Any condition
where clots can form and enter the arteries that supply the eye has
the potential to close off the retinal artery. This can be due to blood clots
that grow on heart valves and then break off as in a patient with endocarditis.
It can also come from fat emboli or from thrombosis as a result of arteriosclerotic
changes in the carotid artery of an older person. One serious complication
of temporal arteritis, a complication associated with the rheumatological condition
"polymyalgia rheumatica", is sudden blindness from central retinal artery
occlusion. Here is a site that shows pictures
of fundoscopy findings. Signs and symptoms: With
central retinal artery occlusion blindness occurs suddenly on one eye. This is
painless. When the physician checks the affected eye for the pupillary light
reflex (light should normally make the pupil smaller), there would be a poor or
no such reflex. On the other hand the pupil of the same affected eye may respond
very quickly when the other eye is tested with light. Diagnostic
tests: Apart from pupillary reflexes and lack of vision there are
other findings. In the first three days the eye specialist using fundoscopy can
see a lighter colored area where there is no blood flow to the affected retina.
At the same time there is a cherry-red spot in the "fovea", the area
of the retina where most of the daytime vision normally takes place. Here
is a link where this can be seen (pictures
of fundoscopy findings). When you click on the images, they enlarge.
Treatment: Unless the treatment is promptly started
within less than 6 hours, there is no hope to restore vision in the affected area.
Treatment is directed at reducing the eye pressure (intraoccular pressure), identifying
and attempting to resolve the clot and to treat any other eye disease or other
underlying medical condition.
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