- What is retinal thrombosis?
- Causes of retinal thrombosis
- Retinal thrombosis symptoms
- Diagnostics of the retinal thrombosis
- Retina treatment
What is retinal thrombosis?
Retinal thrombosis is an eye disease caused by an acute circulatory disorder in the central retinal vein (PCV). Synonyms for PCV thrombosis: retinopathy of venous stasis, hemorrhagic retinopathy.
Depending on the localization, retinal vein thrombosis is divided into occlusion (blockage) of the central vein itself and blockage of its branches. When the branches are occluded, only the peripheral part of the retina, which supplied the affected branch with blood, is involved in the pathological process, and when the central vein is blocked, most of the retina, since in this case the thrombus is located at the level of the optic nerve. Therefore, the symptoms and prognosis in these two cases are slightly different.
The incidence of PCV thrombosis is 2.14 per 1000 people, and among patients with glaucoma - 17.3 per 1000 people. The disease is observed mainly in people over the age of 40, the average age of patients is 51–65 years. Occlusion of the branches of the PCV is more common (67% of cases). Thrombosis of PCV and its branches ranks second in prevalence after diabetic retinopathy among retinal vascular diseases.
Causes of retinal thrombosis
Isolated retinal vein thrombosis is uncommon.
It usually develops under the influence of other diseases, primarily the following:
- Systemic vasculitis (connective tissue diseases affecting blood vessels);
- Malignant diseases of the blood and hematopoietic organs (macroglobulinemia, polycythemia, myeloma), characterized by increased blood clotting, as well as thrombophilia.
In most diseases, the wall of the arteries thickens, hardens and compresses the adjacent vein, as a result of which blood flow in the vein slows down and a blood clot forms. Stagnation of blood in a vein increases vascular permeability, causes a reverse flow of blood into the capillaries of the retina, its exit into the intervascular space and an increase in intraocular pressure, which can result in retinal hemorrhage and its edema.
The following diseases and conditions can also cause thrombosis:
- Infectious diseases (influenza, sepsis, sinusitis, oral infections);
- Ophthalmic hypertension;
- Swelling of the optic nerve;
- Intraocular tumors;
- Thyroid ophthalmopathy (orbitopathy).
Additional risk factors are:
- Other endocrine pathologies;
- Sedentary lifestyle;
- Alcohol abuse.
Retinal thrombosis symptoms
There are two types of thrombosis of the PCV and its branches:
Ischemic (complete occlusion, covering an area of at least 10 diameters of the optic nerve head) - characterized by serious damage to the blood flow, extensive retinal hemorrhages, a significant decrease in visual acuity, a high risk of complications;
- Non-ischemic (incomplete occlusion) - retinal lesions are less pronounced, visual acuity deterioration is insignificant.
The safety of vision directly depends on the degree of ischemia. Central vein thrombosis can develop within a few hours and manifests itself as a sudden painless deterioration or complete loss of vision in one eye. Frequent complaints with vein thrombosis are fog or dark spots before the eyes, distortion of objects. However, if the macula (central part) of the retina is not affected, normal visual acuity may remain. In this case, thrombosis is often discovered by chance during a routine examination.
There are several stages in the development of the disease:
- Prethrombosis - the veins are convoluted, unevenly dilated, blood flow is slowed down, venous stasis is diagnosed in the fundus, there are single hemorrhages. Visual acuity is slightly reduced, periodic fogging is possible, complaints may be absent;
- Direct thrombosis - veins are dark, wide, intermittent, arteries are narrowed, hemorrhages throughout the retina (with lesions of the CVS) and in the vitreous, the boundaries of the optic nerve head are blurred, edema of the macular zone is observed. Symptoms: significant deterioration in visual acuity, blurred vision, limitation of the field of vision;
- Postthrombotic retinopathy - for several months, traces of hemorrhage, pathological neoplasm of vessels on the optic nerve head are determined in the fundus. Vision returns slowly.
Diagnostics of the retinal thrombosis
When collecting anamnesis, the presence of concomitant diseases is revealed.
Physical research methods are used:
- Visometry - checking visual acuity using a table or finger counting;
- Tonometry - measurement of intraocular pressure;
- Perimetry - determination of central or peripheral scotoma (narrowing of the visual field);
- Biomicroscopy - detection of vitreous opacity, iris and pupil defects, etc.;
- Ophthalmoscopy - examination of the fundus for hemorrhages. The clinical picture usually resembles a crushed tomato.
Laboratory methods include general and biochemical blood tests. Also, fluorescence angiography is performed to determine the type of thrombosis and to accurately formulate the diagnosis.
Treatment of thrombosis of the PCV and its branches should be started as early as possible.
Its main tasks:
- Resorption of hemorrhages;
- Restoration of blood flow in the affected vein;
- Removal of retinal edema;
- Improvement of trophism (nutrition) of the retina.
Fibrinolytics (plasminogen, streptodecase injections, hemase) are used to restore blood flow. After them, direct anticoagulants (heparin) are prescribed.
To lower blood pressure, take nifedipine, fenigidine, intramuscular-lasix, which also reduces retinal edema. Timolol (Arutimol, Kuzimolol) is instilled into the eyes to reduce intraocular pressure.
Antiplatelet agents are used to improve microcirculation and prevent recurrent thrombosis: clopidogrel (Plavix), pentoxifylline (Trental).
For symptomatic therapy of retinal inflammation and edema, local and systemic hormonal drugs are used: injections of glucocorticoids Dexamethasone, Diprospan.
Additionally, antispasmodics, vitamins C and group B are prescribed.
The author of the article: Degtyareva Marina Vitalievna, ophthalmologist, ophthalmologist