The retina of the eye is an extremely important structure for eye sight. If the eye is compared to a camera, the retina would be the film where the "picture" is formed. Without the retina, there is no vision. For the retina to function, adequate and proper blood circulation is a must. Fine blood vessels enter the retina and provide oxygen and nutrition. The blood then leaves the retina via the vein. The central retinal vein is located very close to the eye nerve (optic nerve).
What is Central Retinal Vein Occlusion?
Central Retinal Vein Occlusion (CRVO) is caused by a blood clot in the vein that drains the blood from the retina of the eye. The artery brings continuous blood to the retina but the blood can not leave the retina because of the block in the vein. Within a short time, the blood and its fluid start to back up in the retina and start to leak around (this is very similar to dropping a camera and exposing the sensitive film to water). There is immediate loss of vision.
This condition has 2 broad categories which may overlap:
Non ischemic: The milder form of the disease is not caused by a blood clot . This may resolve fully with good visual outcome, or progress to the ischemic type.
Ischemic: The severe form of the disease is due to a blood clot in the vein. These patients are often left with a painful eye with no vision.
How often is the condition diagnosed?
Some physicians indicate that about 60,000 people develop a CRVO each year in the United States. It is a common condition in individuals over the age of 60. CRVO does not have any particular racial preference but is slightly more common in males. Even though the disorder has been reported in all ages, the majority of affected individuals are older than 50 years.
What are risk factors for CRVO?
The majority of individuals who develop CRVO may have one of these conditions:
- Diabetes mellitus
- Heart problems
- Bleeding or clotting disorders
- Some type of collagen vascular disorder
- Use of birth control pill
- Closed head trauma
- Excessive alcohol consumption
How do individuals with CRVO present?
At the initial stage, some may present with
- no symptoms
- decreased vision
- sudden or gradual vision loss
- eye pain when looking at bright lights
- painful blind eye
- redness of the eye
- watering of the eye
How is the diagnosis made?
Whenever vision is altered, you will be quickly referred to an eye doctor. Workup for all eye disorders may include:
- measurement of blood pressure
- blood work
- specialized eye studies
Can one die after developing CRVO?
No, the disorder may make you blind but it does not affect your long term survival.
What is prognosis of CRVO?
If the CRVO is not associated with a blood clot, it may resolve on its own in some patients. Those with a blood clot generally progress to blurred vision. In addition, some individuals with ischemic occlusion will also develop CRVO of the other eye. This usually occurs after 2-3 years.
What happens if the condition is allowed to progress?
As the condition progresses the visual loss continues. New vessels readily develop in the eye which decrease vision and also lead to development of glaucoma (high pressures in the eye).
After a diagnosis of CRVO has been made, many patients are advised by their doctors that the vision may return on its own if nothing is done to the eye. However, spontaneous recovery of vision in CRVO is very uncommon and when it does occur, the amount of recovery is usually very small.
What is treatment for CRVO?
Today, there is no reliable effective treatment to prevent the loss of vision or to improve vision once it is lost.
What are treatment options for CRVO?
Since there is no specific treatment available for CRVO, the thrust of management is geared towards identifying and treating any systemic medical problems to reduce further complications. Because the exact pathogenesis of the CRVO is not known, various medical modalities of treatment have been advocated by numerous physicians with varying success in preventing complications and preserving vision.
What types of medications have been used to treat CRVO?
The following is a list of those advocated treatments:
- Anti-inflammatory agents
- Isovolumic hemodilution (hydrate the individual with fluids)
- Plasmapheresis (remove any bad antibodies)
- Blood thinners such as heparin, Warfarin
- Thrombolytic agents (agents to dissolve clot)
- Systemic corticosteroids
- Injection of blood thinner in the eye (intravitreal)
- Injection of steroids in the eye (intravitreal)
Surgical Care: Laser photocoagulation is the known treatment of choice in treatment of CRVO. This prevents new vessel formation and may prevent further vision loss.
Is there a special diet to help treat CRVO?
Diet should be tailored to systemic medical problems.
What is the role of physical activity when CRVO is diagnosed?
There are no specific restrictions. If you do develop some type of bleeding in the eye, you should avoid strenuous activities, sleep with the head elevated and avoid bending and lifting heavy objects (the grunt and groaning can increase the pressure in the eye).
How can one prevent CRVO?
The best way to prevent CRVO is to ensure that you control any systemic disease that you have (e.g. control your BP and diabetes)
Even though controversial, good control of your glaucoma may also be helpful
Which type of physician deals with CRVO?
In general disorders of the eye are dealt with eye physicians (ophthalmologists). Because the eye is a delicate structure and disorders of the eye can have a profound affect on life, it is imperative that you see an eye doctor anytime you have visual problems.
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