My Mom Is Receiving Avastin For Treatment Of Glioblastoma Multiforme.

My mom is receiving Avastin for treatment of glioblastoma multiforme. She has been having problems with her vision lately, blurry seeing rainbow colors and can't read anything small like a phone. This wasn't a problem until recently. She also thinks she has vertigo because she is having a hard time hearing and feels like she will tip over when she tries to stand from a seated position. Could this be a reaction to the treatment?