Anti-VEGF drugs (also called VEGF inhibitors) slow the abnormal growth of blood vessels associated with certain cancers and degenerative eye conditions, such as age-related macular degeneration. Anti-VEGF stands for anti-vascular endothelial growth factor.
Anti-VEGF drugs work by interfering with either vascular endothelial growth factor (VEGF) which is a signal protein produced by many cells that stimulates the growth of new blood vessels, or by blocking the VEGF receptor so that VEGF cannot bind to it. VEGF and the VEGF receptor play a major role in the formation and growth of new blood vessels during early embryogenesis and the formation of blood vessels from pre-existing vessels at a later stage (this is called angiogenesis). The formation and maintenance of blood vessel structure is important for the progression of cancer, degenerative eye conditions, and other conditions associated with inflammation. There are at least seven types of VEGF and at least three to four types of VEGF receptors.
There are several anti-VEGF drugs currently available including:
- Avastin (bevacizumab)
- Eylea (aflibercept)
- Lucentis (ranibizumab)
- Nexavar (sorafenib)
- Sprycel (dasatinib)
- Sutent (sunitinib)
- Tasigna (nilotinib)
- Votrient (pazopanib).
Abnormal angiogenesis is known to occur in cancer, degenerative eye conditions, and other conditions that involve inflammation. Specific monoclonal antibodies can be used as VEGF inhibitors and particular tyrosine kinase inhibitors are used as VEGFR inhibitors.
Anti-VEGF drugs for diabetic macular edema (DMO) are effective with three to four people out of every 10 experiencing an improvement of 3 or more lines in the visual acuity test at one year. As well as improving vision, anti-VEGF drugs prevent further visual loss and reduce edema.
How do anti-VEGF injections work?
There are three anti-VEGF inhibitors that may be used to treat eye conditions such as diabetic macular edema, myopic degeneration, retinal vein occlusions, and wet age-related macular degeneration. These are
- Avastin
- Lucentis
- Eylea.
The anti-VEGF medication is injected into the vitreous gel in the eye (this is the clear gel that maintains the shape of the eye) and targets a protein involved in the formation of abnormal blood vessels that stops the growth of these blood vessels and reduces bleeding. This reduces fluid build-up, improves vision quality, and prevents ongoing damage to the retina light receptors.
Are anti-VEGF injections painful?
Although the thought of having injections in your eye sounds frightening and horrendous, for most people it is a complete non-event as your doctor numbs your eye and you won’t usually see the needle. There is usually no pain, and the injection is quick. Some people report seeing a black ball in their eye that hangs around for about 24 hours.
How long does it take for anti-VEGF drugs to work for eye conditions?
It usually takes a few months for anti-VEGF drugs to start working for eye conditions and this is why the injection is usually given once every 4 to 6 weeks initially. After your eye(s) respond, you will need to continue treatment indefinitely, generally every 12 weeks or longer to maintain the effect. In one study, 50% of patients needed yearly injections, and 25% were able to stop injections for a year or more due after achieving stability.