Thrombosis in the eye

introduction

At a thrombosis it is a Blood clots, which forms in a vessel and can partially or completely close it. This blood clot is also called thrombus designated. Often thromboses arise in the Veinsbecause, on the one hand, the blood flow velocity is lower here than in arterial vessels and, on the other hand, the vein walls are thinner. Thromboses usually occur in vessels distant from the heart, such as in the leg or pelvic veins. But also a thrombosis in the eye is possible. The blood clot forms in a vein that connects the Retina supplies and therefore leads to impaired vision. Rapid treatment is therefore of great importance in order to be able to reverse the damage that has occurred.

causes

In addition to the generally applicable developmental factors for thrombosis, a number of diseases are associated with a particularly high risk of thrombosis in the eye. This includes a permanent increased pressure in the eye, as well as diabetes mellitus and arterial hypertension. The blood clot in the retinal vein means that the oxygen-depleted blood can no longer be sufficiently transported away from the retina. In the acute phase there is therefore bleeding into the retina. In the long term there will be a Insufficient supply of oxygen for the retinal cells, which in turn causes permanent visual impairment. In addition, in the chronic phase of the disease there are often vascular growths in the retina, which under certain circumstances can lead to further loss of vision.

Symptoms

A thrombosis in the eye is common for those affected not painful and only goes with one Vision deterioration hand in hand. Depending on which vein is affected by the occlusion, the localization of the impaired vision can also differ. For example, the upper or lower field of vision can be more likely to be affected, but a more lateral or central loss of vision is also conceivable. It is particularly impressive for those affected when the Middle of the retina either directly (through the closure of the vein itself) or indirectly (through water retention in the center of the retina). If the latter is the case, those affected often report it, especially in the morning about a deterioration in vision in the form of a Veil vision. This is due to the fact that the transport of water from the retina is lower, especially at night, and this can therefore preferentially accumulate there until the early hours of the morning.

However, it is important to distinguish a thrombosis in the eye very clearly and early on from a stroke, as this is often associated with similar symptoms.

Diagnosis

For the clear determination of a thrombosis The ophthalmologist usually runs one in the eye Reflection of the retina (also: Ophthalmoscopy) by. To do this, it shines into the affected eye and can thus detect changes in the retina. The main characteristic of thrombosis in the eye is the striped or punctiform hemorrhage in various areas of the retina.

Treatment / therapy

First and foremost, if there is a thrombosis in the eye, a blood thinning therapy (also: hemodilution) aimed at. This is particularly effective when started within a few hours of the event. This treatment method is intended to improve the blood circulation in the retina in the long term and thus reduce or completely eliminate the impaired vision. Therapy with the blood-thinning medication should last about four to five weeks.

Therapy is also available VEGF antibodies (such as ranibizumab) conceivable. VEGF (vascular endothelial growth factor) is a messenger substance that is formed for the formation and growth of new vessels. Treatment with antibodies against VEGF should therefore inhibit this messenger substance in its effect and thus counteract the growth of blood vessels in the retina. This medication must be administered into the eye using a syringe.

Another drug used for treating ocular vein thrombosis is a Implant, which also has to be injected into the eye and releases cortisone there over a period of several months. This is supposed to suppress the inflammation of the retina and have a positive effect on the healing process.

If there are already vascular growths, they can be removed with the help of Laser coagulation and thus new hemorrhages into the retina with further complications are prevented.

Finally, there is also a surgical procedure for treating an ocular vein thrombosis. This is the radial optic neurotomy (RON for short), in which small incisions are made in the area of ​​the optic nerve head, which are intended to improve blood circulation in the retina in the long term. However, the operation is relatively complex and only suitable for occlusions of the central vein.

Medical therapy

Probably the most commonly used drugs for treating thrombosis in the eye are drugs to thin the blood (also: hemodilution). The primary purpose of these substances is to dissolve the thrombus that has formed and thus enable blood flow to the retina again.

There are also two drug therapies that require the drug to be injected into the eye due to its solubility properties. On the one hand, a thrombosis in the eye can also be treated with antibodies. These are directed against VEGF (vascular endothelial growth factor). This is a messenger substance that is crucial for the formation of new vessels. The administration of this drug is intended to counteract the random proliferation of new vessels in the retina, as this can be associated with permanent visual impairment.

The second drug that is administered using a syringe is an implant that remains in the eye and continues for several months cortisone gives. This counteracts an inflammatory reaction and thus supports the healing process of the damaged retina.

Application through a syringe

Medicines that have to be applied into the eye by means of a syringe usually have solubility properties that make this necessary. This is an injection into the vitreous humor (also: intravitreal injection). This procedure is usually carried out on an outpatient basis and can be carried out both in the hospital and in specialized ophthalmological practices. To do this, the eye is initially using Drop widenedso that it is less sensitive to light and glare. In this state, the pupil can no longer contract well and enables the treating doctor to look better into the eye. Then one follows local anesthesia with the help of eye drop. To avoid possible blinking during the injection, the eyelid is usually held by an instrument called Eyelid lock held up. Due to the local anesthesia, this is usually not or barely noticeable. The actual drug is then finally injected into the whites of the eye with a syringe. The person concerned only feels a slight pressure from this. After the procedure, patients should not drive a car or bicycle and, if necessary, wear dark glasses for a few hours, as they are more sensitive to light. After a few hours, however, all changes have disappeared and no further treatment is required.

Can a thrombosis in the eye be cured?

A thrombosis in the eye is currently treatable in principle, but mostly remains permanent visual impairment. The original state after such an event is rarely restored.

However, one has to distinguish between the occlusion of a vein and the occlusion of an artery. The course is at arterial vessels most of time more dramatic and therefore has to be treated within a few hours in order to be able to save some of the eyesight. At venous occlusions however, mostly only helps regular Diagnostics in advance to prevent such blockages. The therapy results are usually not completely satisfactory for those affected.

Nonetheless, it is treatment a thrombosis in the eye indispensable, because even if the original vision cannot be restored, various consequential damages and further complications can be prevented in this way.

stroke

In principle, the mechanism by which a thrombosis develops in the eye is exactly the same as in a stroke. Only when the vascular occlusion occurs, the thrombus blocks a vessel that supplies the retina. If this happens in a vessel that supplies the brain, it is called a stroke.

The main risk factors that can lead to a thrombosis in the eye are largely identical to those for an increased risk of stroke. These are diseases such as diabetes, high blood pressure and general changes in the blood vessels.

In summary, one can say that a thrombosis in the eye and a stroke are closely related. The occlusion of a vessel in the eye can therefore be an indication of an increased risk of stroke and should always be clarified further.