What is Anti-VEGF Therapy?

Macular degeneration, especially age-related macular degeneration (AMD) is one of the most common eye conditions that can cause vision loss in older individuals. There are 2 kinds of AMD: dry AMD and wet AMD (also called neovascular AMD).

In wet AMD and myopic macular degeneration (MMD), new abnormal blood vessels form underneath the retina. If these vessels leak fluid or bleed, the retina may be damaged, resulting in vision loss.

While there is no cure for macular degeneration, there are treatments available, including eye injections for wet AMD and myopic CNV found in MMD. These injections can also be used in any eye disease that involves choroidal neovascularization, or the formation of the abnormal new blood vessels.

The drugs used in these eye injections are called anti-VEGF drugs. These injections can help slow the progression of AMD or MMD and are the most common and effective clinical treatment for this kind of condition. Eye injections can take some time to get used to, but they have many benefits.1

What is VEGF?

VEGF is a protein called vascular endothelial growth factor. Generally, this is a protein that encourages the growth of new blood vessels as part of a healing response to injury. However, when it is produced in the eye, it promotes the growth of abnormal blood vessels beneath the retina in the choroid. This can be dangerous.2

VEGF also increases the permeability of existing blood vessels, which means they have an increased likelihood of leaking. When the abnormal blood vessels leak, it causes swelling. This can damage retinal cells and may even lead to retinal detachment, leading to impaired vision.2

How does anti-VEGF therapy work?

Anti-VEGF drugs work by blocking VEGF and minimizing its effects. Although VEGF can be beneficial in other parts of the body to promote healing and blood vessel formation, it is problematic when overproduced in the eye due to the delicate nature of the retina and surrounding tissue layers. When trying to minimize VEGF in the eye, it is important to concentrate the effects of any anti-VEGF drug in the eye and minimize the effects in the rest of the body. This means that a direct injection into the eye is the most effective.1,2

Anti-VEGF drugs inhibit VEGF by binding or trapping it, thereby preventing it from promoting the growth of new abnormal blood vessels. Synthetic nucleic acid or protein molecules called aptamers have been designed to bind VEGF and prevent it from exerting downstream effects.1,2

Formulations of anti-VEGF drugs

There are several different anti-VEGF drugs, including:1,2

Although bevacizumab was actually first developed for use in colon cancer, it is safe and often used off-label in the eye. All of these drugs have been shown to be effective for treating wet AMD. Each medicine has a slightly different structure, and aflibercept works in a slightly different way than bevacizumab and ranibizumab.1,2

What are the possible side effects of anti-VEGF drugs?

Side effects can vary depending on the specific treatment/drug you are taking. Most side effects of the therapy are related to the injection procedure itself rather than the drug. After the eye injection, you might have some soreness, floaters, or foggy vision, all of which should go away in a day or 2.2

More serious complications of intraocular injections can include infection, retinal detachment, or bleeding inside the eye. Sometimes, a small amount of bleeding over the white part of the eye may occur from a broken blood vessel. This is called a subconjunctival hemorrhage. While unsightly, it will not affect your vision long-term and often resolves on its own over several weeks.2

What do I do if I experience any side effects or complications?

You can take over-the-counter pain relievers like Tylenol, or hold cool compresses to your eye for 10 minutes at a time to treat the more common side effects. After an injection, if you feel any serious pain or have changes in your vision, call your doctor immediately. If there are signs of a retinal detachment, this needs to be addressed as soon as possible. If it turns out to be nothing, it’s always better to be safe than sorry. Do not be nervous about staying vigilant about your eye health.

Things to consider about anti-VEGF drugs

If you and your doctor decide to pursue treatment with anti-VEGF drugs via eye injections, the injections will be administered in the office on a treatment schedule. This is typically every 4 to 6 weeks for a certain period of time, and then possibly less frequently later on, depending on treatment response.3

If you have been diagnosed with wet AMD or MMD, your doctor might have suggested anti-VEGF therapy for you. Talk with him/her about any concerns you might have, do your research from trusted, reputable sources, and come to a decision that is right for you. Anti-VEGF therapy has been shown to be effective for many people and can slow down the progression of wet AMD or MMD. It may help preserve your remaining vision and may even restore some vision loss related to swelling or bleeding in the retina.

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Written by Jaime R. Herndon | Reviewed October 2021