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What Is Anti-VEGF Therapy?

Reviewed by: HU Medical Review Board | Last reviewed: May 2023

Macular degeneration, especially age-related macular degeneration (AMD), is one of the most common eye conditions that causes vision loss in older people. There are 2 kinds of AMD: dry AMD and wet AMD (also called neovascular AMD). Wet AMD can be treated with anti-VEGF drugs.


In wet AMD and some other forms of macular degeneration, new, weak blood vessels form in the eye. If these vessels leak fluid or bleed, the structures of the eye may be damaged. This damage leads to vision loss and even blindness.1,2

While there is no cure for macular degeneration, there are treatments, including eye injections for wet AMD. These injections can also be used in any eye disease that causes abnormal, weak blood vessels to grow (choroidal neovascularization).1,2

The drugs most often used in these eye injections are called anti-VEGF drugs. These injections may help slow the progression of AMD. Eye injections can take some time to get used to, but they have many benefits. Anti-VEGF treatments improve vision for 1 in 3 people and at least keep vision from getting worse in 9 out of 10.1,2

The role of VEGF in eye health

VEGF is a protein called vascular endothelial growth factor. It is found throughout the body and helps your body make new blood vessels when you need them. However, when too much VEGF is made in the eye, it causes new, weak blood vessels to grow. These blood vessels damage the eye and lead to poor vision or blindness.2

VEGF also increases the chances that blood vessels in the eye will become leaky. When eye blood vessels leak, it causes swelling. This can damage the retina and may lead to retinal detachment and worse vision.2

How does anti-VEGF therapy work?

Anti-VEGF drugs work by blocking VEGF and minimizing its effects. While 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.1,2

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 direct injection into the eye is the most effective.1,2

Anti-VEGF drugs inhibit VEGF by binding or trapping it. This prevents it from promoting the growth of new abnormal blood vessels. Lab-made molecules called aptamers have been designed to bind VEGF and prevent it from minimizing effects beyond the eye.1,2

Examples of anti-VEGF drugs

There are many anti-VEGF drugs, including:1-4

All of these drugs are effective for treating wet AMD. Each drug has a slightly different structure, but most are delivered through an injection into the eye. Susvimo requires a small implant to be inserted into the eye, and the drug is then released from that implant.1-4

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

Most of the side effects of anti-VEGF treatments come from the injection, not the medicine itself. And, side effects may vary some by treatment. The most common side effects or complications clear in a day to 1 to 2 weeks and include:5,6

  • Ache or pain in the eye that lasts a day or 2
  • Foggy vision
  • Floaters that clear in about a week
  • Bruising in the white of the eye where the needle goes in
  • Sore or gritty eyes

Your doctor may recommend you take over-the-counter pain relievers like Tylenol or hold a cool compress to your eye for up to 10 minutes to make you more comfortable. Most doctors ask you to use antibiotic eye drops for a day or 2 afterward to prevent infections.5,6

If you feel any serious pain or notice changes in your vision, call your doctor right away. These could be signs of serious complications like retinal detachment or infection.5

These are not all the possible side effects of anti-VEGF treatments. Talk to your doctor about what to expect when taking these drugs. You also should call your doctor if you have any changes that concern you.

Things to know about anti-VEGF drugs

If you and your doctor decide to pursue treatment with anti-VEGF drugs, the injections will be given in the office on a set schedule. The schedule depends on the drug you are taking and how well you respond to the treatment. Cost may also vary widely depending on which anti-VEGF drug you take. You may still need other treatments for your macular degeneration along with an anti-VEGF drug.2

Before beginning treatment for macular degeneration, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.

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