In wet age-related macular degeneration (AMD), abnormal blood vessels grow under the retina and leak blood and fluid.  This causes rapid damage to the macula, the portion of the eye responsible for fine, detailed central vision. 

 

Avastin (bevacizumab) is an antibody that inhibits VEGF-A, a protein which plays a critical role in the formation of new blood vessels. It was developed for use in cancer and is registered in New Zealand as a cancer treatment. It is very closely related to Lucentis, a medication shown to be extremely effective for AMD and macular oedema from diabetic retinopathy and retinal vein occlusions in clinical trials.  A number of trials have shown that Avastin and Lucentis have very similar effectiveness in treating wet AMD.