Central retinal vein occlusion (CRVO)is a blockage of the main vein responsible for draining blood from the retina. This blockage causes the walls of the vein to leak blood and excess fluid into the retina, which collects in the macula – the part of the eye responsible for detailed central vision – and causes vision to become cloudy and blurred.
There are two types of central retinal vein occlusion:
Non-Ischemic CRVO: Non-ischemic CRVO is a milder and more common form of the disease. In early stage, patients only experience sudden blurred vision. This may progress to become more serious, ischemic CRVO, if left untreated.
Ischemic CRVO: Ischemic CRVO is a more serious form of central retinal vein occlusion and causes more drastic, sudden vision loss. Ischemic CRVO can lead to the development of glaucoma as abnormal blood vessels begin to grow in the eye and increase intraocular pressure. This can be painful as well as causing severe, or even permanent, vision loss.
For patients learning about retinal vein occlusion, please note, there are two variations, “central” and “branch” retinal vein occlusion. This page only covers central retinal vein occlusion. Click here to read about the branch retinal vein occlusion.
Symptoms of Central Retinal Vein Occlusion (CRVO)
The most noticeable symptom of central retinal vein occlusion is a blurring or loss of vision in one eye. In severe cases, complete vision loss occurs. This vision loss is painless and may happen suddenly. Vision loss may gradually worsen over the course of hours or days.
Additional symptoms of central retinal vein occlusion are:
- The appearance of floaters. These shapes resemble small hairs or spots of dust that float within your field of vision
- In severe case, particularly for ischemic CRVO, a build-up of painful pressure in the affected eye
If left untreated, central retinal vein occlusion can lead to complete and permanent vision loss / blindness in the affected eye.
Causes ofCentral Retinal Vein Occlusion (CRVO)
Central retinal vein occlusion occurs when a blood clot blocks the main vein from draining blood from the retina. Narrowing of the arteries is a major factor in the development of central retinal vein occlusion. This can be compounded by other health conditions (mentioned below) that can slow the blood stream, block the walls of the vein, and form abnormal blood vessels; all of which contribute to the formation of blood clots.
Increased risk factors for developing central retinal vein occlusion are:
- Hypertension / high blood pressure
- Glaucoma or those with high intraocular pressure in their eye(s)
The risk of this disease increases with age. Central retinal vein occlusion is more likely to affect patients over the age of 50 years old.
Diagnosing Central Retinal Vein Occlusion (CRVO)
If you experience sudden vision loss, you should contact your eye care professional. Central retinal vein occlusion is a serious condition and requires prompt treatment from a retinal specialist.
Central retinal vein occlusion can be diagnosed through a dilated eye exam and slit-lamp examination. Intraocular pressure will need to be measured, as ischemic CRVO can lead to the development of glaucoma and raise intraocular pressure, causing further vision loss.
Additional diagnostic testing using fluorescein angiography may also be necessary in order to evaluate the formation of abnormal blood vessels, leakage of these blood vessels, and the presence of any other retina conditions.
Treatment ofCentral Retinal Vein Occlusion (CRVO)
Determining the underlying cause of the retinal vein blockage is the first step in treating central retinal vein occlusions.
Because blocked veins cannot be unblocked, treatment is intended to stabilize the condition and reduce swelling of the macula. Many patients regain some of their previous vision, but rarely will vision return to 100% normal. There is presently no cure for central retinal vein occlusion.
Panretinal photocoagulation laser treatment is used to reduce growth of new blood vessels. Central retinal vein occlusion is treated using anti-VEGF medications, such as intravitreal injections of Avastin or Lucentis to reduce macular swelling. These treatments helps stabilize vision by sealing off or destroying leaking blood vessels that interfere with the macula and cause swelling.
Central retinal vein occlusion istreated using anti-VEGF medications, such as intravitreal injections of Avastin or Lucentis to reduce macular swelling.
In addition to the treatment of retinal vein occlusion, it is important that patients responsibly manage their health in order to reduce their risk of developing further eye conditions in the future.
Recommended lifestyle changes to reduce the risk of retinal vein occlusion are:
- Properly managing diabetes
- Eating a low-fat diet
- Not smoking
- Maintaining an ideal weight
- Getting regular exercise