Branch Retinal Vein Occlusion (BRVO)
WHAT IS BRANCH RETINAL VEIN OCCLUSION (BRVO)?
Branch Retinal Vein Occlusion (BRVO) is a blockage of one or more branches of the central retinal vein, which runs through the optic nerve. Branch Retinal Vein Occlusion symptoms include:
- Peripheral vision loss
- Blurred or distorted central vision
BRVO is one of the two types of retinal vein occlusions. When there is blockage of the retina’s central vein, it is called a central retinal vein occlusion (CRVO).
BRVO is more common in patients with high blood pressure, diabetes, and atherosclerosis. Smoking is also a significant risk factor. However, in some cases, there is no apparent underlying cause. Underlying medical conditions that are considered associated risk factors such as high blood pressure require evaluation and treatment with a primary care physician.
Branch Retinal Vein Occlusion (BRVO) Eye Photos
Why does Branch Retinal Vein Occlusion cause decreased vision?
With a BRVO, the circulation of blood through the affected vein is either halted or reduced, often resulting in an accumulation of blood and fluid (macular edema) within the retinal tissue. The reduction in blood flow (ischemia) and macular edema both contribute to decreased visual acuity.
What is likely to be the visual outcome?
While gradual spontaneous improvement in vision is possible in a minority of patients, without treatment the vision in most patients will remain decreased or even worsen.
What can be done to improve vision?
Unfortunately, BRVO cannot be cured, however, there are effective treatments that can help patients maintain or improve their visual outcome by reducing the associated macular edema. Treatment options include intravitreal injection (injection of medicine into the eye) and laser.
What results can I expect with BRVO treatment?
Intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors such as Lucentis (FDA approved), Eylea (FDA approved), and Avastin (used off-label) or steroids such as triamcinolone and Ozurdex (FDA approved) can help maintain or improve vision.
Laser is sometimes used to treat macular edema but is now considered a second-line treatment for most cases based on visual outcomes and limitations. For instance, if there is significant hemorrhage in the retina, laser cannot be performed until the hemorrhage resolves spontaneously, which may take a few months.
Other problems related to Branch Retinal Vein Occlusion?
In response to a BRVO, some patients will develop an abnormal growth of fragile new blood vessels (retinal neovascularization) on the surface of the retina months or years after initial diagnosis. These blood vessels generally do not have any associated symptoms unless they rupture and bleed.
In general, rupture is spontaneous and unpredictable, and if there is a significant amount of hemorrhage into the vitreous cavity of the eye, vision can be dramatically reduced. Although the blood may resolve spontaneously in some cases, it can take weeks or months depending on the severity.
If neovascularization is detected on a follow-up office visit, laser can be administered to shrink the abnormal fragile vessels in order to minimize the risk of vitreous hemorrhage and vision loss. Laser does not guarantee that there will be no future hemorrhaging, but it does significantly lower this risk. Occasionally if there is a very severe or persistent (non-clearing) vitreous hemorrhage, vitrectomy surgery may be warranted to remove the blood.
Are there any restrictions or precautions?
There is no generalized restriction on visual or physical activities such as reading, watching TV, and exercise. However, having blurred vision in one eye may hamper depth perception, so one may need to exercise caution with stairs, exercise equipment, pouring hot liquids, and driving. In severe cases, one may need to temporarily avoid certain activities such as driving, using tools, and operating machinery as a precaution. It is relatively uncommon for a BRVO to occur in both eyes and blurred vision in the affected eye does not in any way harm the “good” eye.
Why should a patient come back before his/her scheduled appointment?
A patient should contact their retinal specialist right away if there is a marked decrease in vision or if the affected eye becomes painful. This applies whether or not any treatment was administered.