This article has been provided by Dr. Huseyin ACAR to give information about ‘’Retinal Artery Occlusion and Its Treatment’ in general terms.
WHAT IS THE STRUCTURE OF RETINA ?
Main task of our eyes is to perceive the incoming light and to transmit it to the vision centers of the brain. This is accomplished by focusing the incoming light upon the nerve layer, which is retina, with the help of the lens system in the embodied structure. The vessel system that nourishes and removes the waste materials must work properly so that the retina can detect the light and transmit it to the brain. The blood circulation in the retina consists of artery and vein system. An artery passes through the optic nerve and reaches the retina and is divided into its branches. Then the system turns towards capillaries. Afterwards, the capillaries come together to form the veins. The veins are towards capillaries. Afterwards, the capillaries come together to form the veins. The veins are combined together to leave the eye through the optic nerve and carry the dirty blood to the heart.
Image 1: The blood circulation in the retina consists of artery and vein system
WHAT ARE THE CAUSES OF RETINAL ARTERY OCCLUSION ?
The most important cause of blockages in the arterial system of the retina is blood clots. These clots usually originate from the large veins in our neck or from our heart. Deterioration of the structure of the vessel wall may occur due to the diseases such smoking, hypertension, cholesterol and diabetes or to the diseases associated with aging. Clots form gradually in the areas where this degradation occurs. These clots also break away from their site and travel to the organs such as the eye or the brain, causing the vessels to become clogged.
WHAT ARE THE SYMPTOMS OF RETINA ARTERY OCCLUSION ?
Occlusion in the retinal arterial system causes sudden and painless vision loss in the patient. The reduction of vision is very obvious, if the clogged vessel is the main artery. When one of the branches of the artery is obstructed, the patients complain that they cannot see a certain area of sight because the cells only in this area that are fed by this vessel are damaged. When vascular occlusion occurs, the body attempts to dissolve the clot to protect itself. If the organism can melt the clots quickly, the cells begin to function again and the complaints on visual impairment disappear, however if it cannot melt quickly, then the cells begin to die after a certain period of time and thus permanent damage happens.
HOW IS THE DIAGNOSIS AND TREATMENT OF RETINAL ARTERY OCCLUSION ?
In retinal artery occlusion, diagnosis is usually made with normal examination. In some cases, it may be difficult to diagnose it. In such cases, supporting tests such as eye angiography and OCT may be required to diagnose. Unfortunately, the treatment results are not promising. There are two reasons for this. The first one is that the cells in the retina layer are very sensitive and cannot survive without oxygen for a long time, and the second one is the failure to replace the cells that are damaged with new cells. In the early stages of the treatment, the amount of damages may be lowered by forcing the clot to travel into the more smaller vessels as the clots can be dislocated from their original sites by decreasing of intraocular pressure and applying messages to the eye. Another method in the treatment of the disease is hyperbaric oxygen therapy. In this method, the oxygen concentration level in the blood is raised and thus the cells already damaged but still alive are healed. The earlier the treatment is started in hyperbaric oxygen therapy, the greater the chance is to get a positive response for the treatment. .
Finding the main cause of retinal artery occlusion is at least as important as treating the disease. If the cause of the disease is a clot originated from the cardiovascular system and in case that this is not treated properly, another clot originating from the same region may also cause more severe situations by entering into the brain or into the other eye.
SUMMARY
Retinal arterial occlusions are the result of cases where the vessels feeding the nerve layer of our eyes get clogged by usually a blood clot. The source of the blood clot is usually the arteries in our neck or the heart. The disease manifests itself as sudden and painless vision loss. Early diagnosis and treatment is very important factor. The other more important point is to treat the root cause of the disease. Otherwise, a new blood clot from the same origin can cause more serious consequences.