Types and what happens in the eye
A distinction is made between central vein occlusion, when the entire outflow from the retina is affected, and branch occlusion, when only one of the branches is blocked and the corresponding part of the visual field is lost. The degree of ischemia is assessed separately: if the capillaries are preserved, the form is considered non-ischemic and proceeds more mildly; if a significant part of the retina is left without blood flow, the form is ischemic, vision decreases more, and in response to oxygen starvation, new defective vessels begin to grow. They can block the outflow pathways of intraocular fluid and cause severe secondary glaucoma.
- Central retinal vein occlusion
- Occlusion of a branch of the central vein
- Non-ischemic form - better prognosis
- Ischemic form - risk of newly formed vessels
- The main reason for decreased vision is macular edema.
- Late complication - neovascular glaucoma
Causes and risk factors
The retinal artery and vein pass through a common connective tissue membrane. With hypertension and atherosclerosis, the arterial wall thickens and compresses the vein, blood flow slows down, and a blood clot forms in this place. Therefore, the main set of risk factors is cardiovascular: high blood pressure, high cholesterol, diabetes, smoking, overweight, and lack of exercise. Increased intraocular pressure and glaucoma separately increase the risk. In people under fifty years of age, the cause may be blood clotting disorders, vasculitis and the use of hormonal contraceptives.
- Arterial hypertension
- Atherosclerosis and high cholesterol
- Diabetes mellitus
- Glaucoma and increased intraocular pressure
- Smoking, obesity, sedentary lifestyle
- Blood clotting disorders and vasculitis in young people
Symptoms
A typical beginning is that a person discovers in the morning that one eye sees as if through foggy glass, or notices that part of the vision has fallen out. There is no pain, redness or discharge, so many people put off visiting the doctor, hoping that it will go away. With branch occlusion, complaints may be minimal and limited to blurriness in one sector. Vision sometimes fluctuates: worse in the morning, a little better in the afternoon. Weeks or months after ischemic occlusion, severe pain and redness may appear - a sign of developed secondary glaucoma.
- Sudden loss of vision in one eye
- A veil or spot before the eye
- Loss of a sector of the field of view
- Curvature of lines due to macular edema
- No pain in the acute period
- Late pain and redness in neovascular glaucoma
Diagnostics
The fundus picture is very characteristic: dilated convoluted veins, multiple hemorrhages in the form of flames, swelling of the optic disc and macula. OCT shows how thick the macula is and serves as the main tool for monitoring treatment. Fluorescein angiography identifies areas left without blood flow, and thereby distinguishes between ischemic and non-ischemic forms. Be sure to measure intraocular pressure in both eyes. At the same time, a general examination is needed: pressure, lipid spectrum, sugar, coagulation parameters, and in young people - an expanded search for the cause.
- Fundus examination with pupil dilation
- Optical coherence tomography of the macula
- Fluorescein angiography
- Measuring intraocular pressure
- Computer perimetry
- Lipid spectrum, glucose, coagulogram, consultation with a therapist
Treatment
It is impossible to dissolve an already formed blood clot in a retinal vein, so treatment is aimed at the consequences. The main thing is to eliminate macular edema, on which central vision depends: for this, intravitreal injections of drugs that suppress vascular growth factor are performed in a course under OCT control; If necessary, hormonal implants are used. In the ischemic form, laser coagulation of the retina is performed to prevent the growth of new vessels and secondary glaucoma. At the same time, the therapist or cardiologist selects treatment for hypertension, diabetes and lipid metabolism disorders - without this, the risk of a repeat episode in the second eye is high.
- Intravitreal injections for macular edema
- Hormonal implants according to indications
- Laser coagulation for ischemic form
- Regular monitoring using OCT
- Treatment of hypertension, diabetes, dyslipidemia
- Smoking cessation and weight control
