Can I have breast augmentation surgery if I have Idiopathic Intracranial hypertension?

You really would need to get the okay from your neurologist. I am not knowledgeable enough in the condition and your case in particular especially in regard to the effect of anesthesia. I suspect it will be okay to proceed just make sure to check with your neurologist.

I would presumably say yes everything should be fine as long as everything has been stable, however two key factors need to be assessed.  Your neurologist will have to be on board and aware that you are planning on undergoing breast augmentation surgery and possibly a tummy tuck under general anesthesia and your anesthesiologist will need to be aware as well.  
As long as your neurologist clears you for the surgery and feels that you are low risk, then the anesthesiologist will also have to be aware of the circumstances as well.
Make certain you see a board certified plastic surgeon and make certain your surgeon is aware of your IIH.
Hope that helps.