What is it about ?
In the retina, there are three types of blood vessels: arteries, veins, and optic nerve blood vessels. The arteries supply the eyes with oxygen-rich blood, and after the oxygen diffuses, the veins return the blood to the heart. The optic nerve carries information from the retina to the brain. When a blood clot stops the flow of blood to a blood vessel, it is called thrombosis.
There are three types of ocular thrombosis depending on the blocked blood vessel:
- Blocked vein: venous thrombosis,
- Clogged artery: arterial thrombosis,
- Obstruction of an optic nerve blood vessel: optic nerve infarction, medically called “anterior ischemic optic neuropathy” (NOIA) (“ischemia” means “insufficient blood flow”).
In this patient guide, we are only talking about central retinal artery thrombosis, that is, a blood clot in the central retinal artery.
The central retinal artery provides blood supply to the retina and is therefore essential for sight. It is in fact on the retina that the images that we see are formed.
Blockage in this artery is usually caused by a blood clot from the carotid artery or heart. The clot is formed away from the eye and carried in the blood until it gets stuck in the artery.
This condition occurs mostly in older people with a disease cardiovascular, less often in younger individuals who present with heart rhythm disorder or a problem with the heart valves (valve disease). THE’temporal arteritis can also lead to this obstruction, although this is rare.
How to recognize it?
The most common symptom is sudden, painless loss of sight with one eye. About 2 in 10 people affected can now only see light and dark. Usually the sight is just counting the number of fingers raised. The pupil (the central black part of the eye) is dilated.
In case of’temporal arteritis, the person suffers from headache intense and his field of vision is greatly reduced. Visual loss then occurs.
About 1 in 10 people affected have had episodes ofTIA (transient ischemic attack). TIA is caused by a transient blockage of an artery. If it occurs in the eye, it is associated with sudden loss of sight on one side for several minutes, half an hour at most. Afterwards, the vision returns.
In case of’blockage of an artery in the brain, the sight generally drops completely or partially on both sides. Speaking becomes difficult and the person is dizziness.
How is the diagnosis made?
Based on your complaints, the doctor will refer you urgently to the ophthalmologist, who will examine the retina in the eye. This examination must be carried out quickly, since permanent damage to the retina occurs already after an hour and a half.
Then we try to find the cause of the problem with the help of a blood test, a electrocardiogram (ECG), of a ultrasound carotid arteries and a CT scan of the brain.
What can you do ?
Contact a doctor immediately. Start a massage of the eyeball: press it for 10 seconds with the edge of the fist of the hand, then release it suddenly (also for 10 seconds). This way the clot sometimes breaks off and travels further into the blood vessel. Continue in this way until you arrive at the ophthalmologist.
What can your doctor do?
The doctor will give you 250 mg of aspirin and send you to the hospital as soon as possible. If necessary, the fluid will be removed from the eye to lower the pressure in the eye. It is not possible to dissolve the clot in the artery.
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