A retinal vein occlusion is a thrombosis-like narrowing or occlusion in a retinal vein. Depending on where it originates on the retina, it can primarily impair sharp and color vision. The vessels dilate before they close, so that vessel water or blood can leak out and small retinal swellings develop, which can lead to visual impairment in the form of blurred vision or distorted color vision.
What is a retinal vein occlusion?
Retinal vein occlusion (RVV), which is sometimes also referred to as an ocular stroke, is a thrombosis-like complete or partial occlusion of a retinal vein. A distinction is made as to whether the entire retina is affected or only parts of it. In the first case, the retinal central vein is affected and in the latter case “only” side branches of the central vein are affected. For what does cpp stand for, please visit biotionary.com.
The disease is one of the vascular retinal diseases. The completely painless stenosis or complete blockage is usually caused by a blood clot (thrombus). The blood that collects in front of the constriction widens the vein so that its walls become porous and vessel water or blood can escape and small edema form in the retina.
Especially when the papilla (blind spot) or the fovea (yellow spot), the zone of sharpest vision, are affected by the hemorrhage, visual impairment occurs, usually in the form of blurred vision. Other forms of visual impairment can also occur. For example, there are often quadratic field of vision restrictions or temporary blindness.
Causes
Most often, retinal vein occlusion is caused by a thrombus, a blood clot that forms locally or has been brought in from outside and has become “stuck” in one of the retinal veins. Strictly speaking, a vein occlusion due to thrombi that have been brought in is an embolism.
In some cases, due to atherosclerotic changes in the retinal arteries, the veins are compressed a little by the space demands of the arteries. This creates stenoses that impede blood circulation and promote the formation of thrombi. It has been observed that thrombi affecting the retinal accessory veins are often located near the capillary arteriovenous junctions.
The exact reasons why thrombi can form in the retinal veins are not sufficiently known. It is discussed whether an increased hematocrit value, as it occurs after intensive altitude training, can cause retinal vein occlusion. Likewise, general risk factors for the occurrence of thrombosis also increase the risk of developing retinal vein occlusion. Increased intraocular pressure and glaucoma are also considered risk factors.
Symptoms, Ailments & Signs
The beginning of a retinal vein occlusion is often completely painless and symptomless, so that in many cases the disease is only discovered by chance during a routine eye examination by a specialist. The first signs that are noticed are usually a reduction in visual acuity such as blurred vision.
This occurs when a retinal vein in close proximity to the fovea becomes blocked and its function is compromised by developing edema. Typically, the visual impairment is more severe early in the morning than during the day, because the edema in the macula, as the yellow spot is also known, recedes a little as a result of the upright posture of the body.
Diagnosis & course of disease
If retinal vein occlusion is suspected, a careful history is important for further diagnosis in order to identify whether there is an increased risk of RVO. Even a simple visual inspection of the back of the eye using an ophthalmoscope can reveal clear signs of RVV. Typical changes in the blood vessels or bleeding into the vitreous body of the eye appear.
To get a more accurate picture of the type of RVV, a fluorescence angiography can be performed, which clearly shows the course of the veins in the retina. In some cases, optical coherence tomography (OCT) is necessary to complete the diagnosis. It allows changes in the individual layers of the retina to be recognized. The course of untreated disease depends on the location of the retinal vein. If there is bleeding in the area of the fovea, the disease can lead to blindness if left untreated.
Complications
The course of a retinal vein occlusion depends on various factors. There are patients whose vision improves again without treatment. However, if the affected blood vessel is completely blocked and a large area of the retina is no longer supplied with blood, complications will increase. The same applies if the main vein is affected.
A so-called ischemic venous occlusion is present when the retinal blood flow has failed in an area at least ten times as large as the blind spot of the eye. Possible complications include reocclusion of a retinal vein in the other eye within five years, new blood vessel formation and chronic macular edema. The formation of new blood vessels in the eye is stimulated by the retinal vein occlusion in order to be able to supply the eye with sufficient oxygen.
However, the new blood vessels grow uncontrollably and are also fragile. This causes further retinal damage. It becomes dangerous when the blood vessels penetrate into the vitreous body. As a result, tension can build up in the eye, which under certain circumstances can lead to detachment of the retina and blindness in the affected eye.
If the vessels grow into the chamber angle, the fluid may no longer be able to drain completely in this area. As a result, a glaucoma can develop, which leads to blindness. In the case of chronic macular edema, vision also deteriorates noticeably despite treatment.
When should you go to the doctor?
This vein blockage must be treated immediately by a doctor. If left untreated, this disease can cause permanent and, above all, irreversible damage, which can significantly impair the eyesight of those affected. Early diagnosis and treatment can prevent further complications. Pain does not usually occur with this vein occlusion. However, ametropia that occurs relatively suddenly and without any particular reason can indicate this venous occlusion and should be examined by a doctor.
In some cases, color vision is also impaired, so that the affected person suddenly can no longer perceive colors correctly. Furthermore, a yellow spot in the affected person’s field of vision can indicate this vein occlusion and should be examined. Those affected often show a crooked posture of the body and can no longer keep their back upright. At the first signs of the disease, an ophthalmologist or a general practitioner can be consulted. In order to avoid complete blindness, further treatment should usually be carried out by an ophthalmologist.
Treatment & Therapy
If a causative thrombus has been identified, a first goal is to reduce hematocrit (thinning of the blood) to prevent further thrombus formation. VEGF inhibitors (vascular endothelial growth factor blockers) are used to prevent the formation of new vessels with reduced functionality. The drugs are injected directly into the vitreous humor of the eye.
Due to the lack of oxygen in the affected retinal regions, there is an increased incentive for the formation of new blood vessels, but this does not lead to an improvement in the blood circulation situation. The newly formed veins rupture easily, increasing the risk that the functionality of the retina will be impaired by new bleeding.
An additional treatment with cortisone preparations, with which a swelling of the affected areas of the retina should be achieved, is a little controversial. In some cases, laser treatment can improve visual performance. However, the procedure is only indicated for venous branch occlusions, but not for a blockage of the central vein.
Prevention
There are no direct preventive measures that could prevent the formation of a retinal vein occlusion. However, a number of preventive measures and certain activities can reduce the risk of developing RVV. It’s all about keeping the veins healthy and elastic and not giving arteriosclerosis a chance.
Important factors such as a healthy diet with a large proportion of natural foods and light exercise and endurance sports can be seen as important preventive measures. Phases of stress should be able to alternate with phases of rest and toxins that damage blood vessels such as nicotine, alcohol and others should be avoided as far as possible.
A balanced cholesterol level also contributes to prevention. The cholesterol level is considered balanced if the ratio of LDL to HDL does not exceed around 4. The total cholesterol level is less important.
Aftercare
After the successful treatment of a retinal vein occlusion, good follow-up treatment is very important in order to prevent a recurrence of a venous occlusion, but also the development of secondary diseases. The long-term administration of blood-thinning medication (Macumar) is essential here in order to ensure permanent blood circulation in the retina. If glaucoma has occurred, permanent administration of medication that lowers the intraocular pressure (glaupax) may also be necessary.
If diabetes is the underlying disease, it is important that this is also treated permanently, since diabetes that is not treated well promotes the recurrence of venous occlusions. In addition, the INR and Quick values of the blood should be checked regularly. This can be done with measuring devices that are available on prescription at the pharmacy.
However, if bad values are measured, the general practitioner and specialist must be informed. In addition to this, regular check-ups of the fundus of the eye should be carried out by the ophthalmologist in order to detect a recurrence of a retinal vein occlusion at an early stage. In addition, a vitamin K-poor diet (avoiding green vegetables) is recommended to keep the blood thin.
In addition, smoking should be consistently avoided, since tobacco smoke sticks the blood platelets together, increases blood pressure and constricts the vessels. Likewise, the consumption of alcohol should be avoided, as this also has a vasoconstrictive and blood pressure-increasing effect.
You can do that yourself
If symptoms of a retinal vein occlusion are noticed, the doctor should be consulted first. It is important to observe the signs of the disease until you see the doctor. The doctor must then be informed of the symptoms. Possible causes should also be discussed during the consultation with the doctor.
After treatment, the triggering factors must be addressed. High blood pressure is usually the cause, which needs to be treated by changing your lifestyle. A healthy diet and exercise are important components of therapy. Smokers should give up cigarette consumption or at least greatly reduce it. People with diabetes may need to lose weight. A healthy lifestyle also helps if the cholesterol level is too high or if the uric acid level in the blood is too high. In addition, the ophthalmologist should be consulted regularly. The doctor can monitor the course of the disease and suggest further measures.
Homeopathic remedies such as the preparations Aconitum 6X, Arnica 6X, Crataegus 6X or Rauwolfia 6X can help with high blood pressure . Phosphorus and Lachesis can also be used as accompanying medication. The exact dosage and selection must be discussed with the specialist. Various relaxation techniques such as yoga or autogenic training help to lower blood pressure. Likewise, cold-blooded applications, massages or a visit to the sauna. Which measures make sense depends on the cause of the retinal vein occlusion.
