What exactly is retinal vein occlusion?
Retinal vein occlusion occurs when a vein in the posterior part of the eye, more specifically in the light – sensitive layer called the retina, becomes blocked. The retina is responsible for converting light stimuli into electrical signals, before transmitting them to the human brain through the optic nerve.
A retinal vein occlusion obstructs the drainage of venous blood from the eye into the systemic circulation, leading to venous stasis and congestion in the blood supply to the eye, resulting in combined hemorrhages and fluid leakage into the retina. Clinically, this can be observed by twisted veins, white spots, and swelling of the macula and the optic disc.
Which are the types of retinal vein occlusion?
There are 2 types of retinal vein occlusion:
- Central retinal vein occlusion (CRVO): when the central retinal vein (at the level of the optic nerve) is blocked
- Branch retinal vein occlusion (BRVO): when one or more smaller peripheral retinal veins are blocked
Which patients are at risk of developing retinal vein occlusion?
Risk factors for retinal vein occlusion include:
- Diabetes
- Glaucoma
- Hyperlipidemia
- Hypertension
- Atherosclerosis
- Blood clotting disorders
- Smoking
- Thrombophilia
It’s worth noting that if a vein occlusion occurs in one eye, there is a statistically higher risk of the other eye being affected in the future, so monitoring is recommended.
What are the main symptoms of retinal vein occlusion?
The key symptoms are:
- Blurred vision
- Loss of part of the visual fields
- Extensive vision loss
- Floaters (black spots or threads)
- Eye pain and pressure
How is retinal vein occlusion treated?
The primary goal in treating retinal vein occlusion is to maintain stable vision. This is achieved by sealing the blood vessels that are bleeding. The technique used is laser photocoagulation. The laser helps prevent the formation of new pathological vessels (neovascularization).
Intravitreal injections of anti – vascular endothelial growth factor (anti – VEGF) agents, can significantly aid in treating the occlusion. The progress of injection effectiveness is monitored through vision measurements and optical coherence tomography (OCT) exams.
In patients who do not respond to standard intravitreal anti – VEGF injections, a corticosteroid implant is recommended. Vitrectomy surgical procedure, is another option in severe cases.
In general lines, patients should control their diabetes, blood pressure, and cholesterol levels.